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CFP09PPC
IEEE Conference Record – Abstracts
PPC2009
Pulsed Power Conference 2009
The 17th IEEE International Pulsed Power Conference
June 28 – July 2, 2009
Washington, D.C.
Sponsored by: Pulsed Power Science and Technology
Committee of The IEEE Nuclear and Plasma Sciences Society
PPC2009 Conference Website:
ppc.missouri.edu
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IEEE CONFERENCE RECORD – ABSTRACTS The 17th IEEE International Pulsed Power Conference Copyright and Reprint Permission: Abstracting is permitted with credit to source. Libraries are permitted to photocopy beyond the limit of U.S. copyright law for private use of patrons those articles in this volume that carry a code at the bottom of the first page, provided the per-copy fee indicated in the code is paid through Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923. For other copying, reprint or republication permission, write to IEEE Copyrights Manager, IEEE Operations Center, 445 Hoes Lane, P.O. Box 1331, Piscataway, NJ 08855-1331. All rights reserved. IEEE Catalog Number: CFP09PPC ISBN: 978-1-4244-4065-8 Library of Congress: 2009901215 Additional copies of this Conference Record are available from: IEEE Operations Center 445 Hoes Lane P.O. Box 1331 Piscataway, NJ 08855-1331 1-800-678-IEEE Copyright © 2007 by Institute of Electrical and Electronics Engineers, Inc.
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Table of Contents
WELCOME ...........................................................................................................7
PPC2009 COMMITTEE CHAIRS AND STAFF ....................................................9
PPC2009 TECHNICAL PROGRAM COMMITTEE MEMBERS .........................10
PULSED POWER SCIENCE AND TECHNOLOGY COMMITTEE.....................10
ORAL SESSION CHAIRS ..................................................................................11
POSTER SESSION CHAIRS .............................................................................11
CONFERENCE SUPPORTERS AND SPONSORS ...........................................12
18TH INTERNATIONAL PULSED POWER CONFERENCE ..............................13
PREVIOUS PULSED POWER CONFERENCES...............................................14
CONFERENCE LOCATION ...............................................................................15
ABOUT DC.........................................................................................................15
CONFERENCE FORMAT ..................................................................................16
STUDENT TRAVEL GRANT..............................................................................16
IEEE ARTHUR H. GUENTHER PULSED POWER STUDENT AWARD ...........17
REGISTRATION FEES ......................................................................................17
REGISTRATION.................................................................................................18
PUBLICATIONS.................................................................................................19
JOB PLACEMENT CENTER .............................................................................19
SOCIAL EVENTS AND COMPANION ACTIVITIES ..........................................20
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TECHNICAL SESSIONS....................................................................................24
CONFERENCE RECORD ABSTRACTS .........................................................102
O1: E-BEAM DRIVEN X-RAY SOURCES .......................................................104
O2: COMPACT PULSED POWER...................................................................109
O3: NARROW BAND AND ELECTRON DEVICES.........................................115
O4: HIGH ENERGY DENSITY PLASMAS – Z PINCHES................................119
O5: RF/HPM SYSTEMS AND EFFECTS .........................................................124
O6: PULSED POWER SOURCES – HIGH CURRENT ACCELERATORS .....129
O7: EXPLOSIVE PULSED POWER 1..............................................................135
O8: HIGH ENERGY DENSITY PLASMAS – APPLICATIONS ........................141
O9: INTENSE ELECTRON AND ION BEAMS AND PLASMAS......................146
O10: PULSED POWER SWITCHES AND COMPONENTS – CLOSING SWITCHES.......................................................................................................151
O11: PULSED POWER SWITCHES AND COMPONENTS – SOLID STATE SWITCHES.......................................................................................................156
O12: EXPLOSIVE PULSED POWER 2............................................................162
O13: ADVANCED DIELECTRICS....................................................................168
O14: PULSED POWER SYSTEMS..................................................................173
O15: REPETITIVE PULSED POWER AND HIGH CURRENT PULSERS .......178
01P: MICROWAVE AND RF SOURCES, CHARGED PARTICLE BEAMS AND SOURCES, DIELECTRICS AND ENERGY STORAGE...................................183
02P: HIGH ENERGY DENSITY PLASMAS AND PULSED POWER SWITCHES AND COMPONENTS .......................................................................................216
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O16: ELECTROMAGNETIC LAUNCHERS AND PULSED POWER SYSTEMS..........................................................................................................................251
O17: PULSED POWER CAPACITORS ...........................................................256
O18: POWER ELECTRONICS AND SYSTEMS..............................................261
O19: BREAKDOWN PHENOMENA IN GASES, LIQUIDS & SOLIDS ............268
O20: INDUSTRIAL, COMMERCIAL, & MEDICAL APPLICATIONS ...............274
03P: INDUSTRIAL, COMMERCIAL, & MEDICAL APPLICATIONS AND EXPLOSIVE AND COMPACT PULSED POWER............................................281
04P: PULSED POWER SOURCES, PULSED POWER SYSTEMS, DIAGNOSTICS, AND POWER ELECTRONICS & SYSTEMS ........................321
O21: INDUSTRIAL, COMMERCIAL, & MEDICAL APPLICATIONS ...............365
O22: BULK OPTICAL SWITCHES AND COMPONENTS ...............................371
AUTHOR INDEX...............................................................................................377
TECHNICAL SESSION GUIDE........................................................................389
MAP OF HOTEL...............................................................................................391
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WELCOME WELCOME On behalf of the Pulsed Power Science and Technology (PPS&T) Standing Committee of the IEEE Nuclear and Plasma Sciences Society, I am pleased to welcome you to the 17th IEEE International Pulsed Power Conference (PPC2009) held in Washington, D.C. from June 28th through July 2nd, 2009. This conference is held biennially and serves as the principal forum for the exchange of information on pulsed power science, technology, and engineering. The proceedings also serve as the major archival resource of papers published in this field. Historically, the conference has significant international participation, and this year is expected to be no exception. Approximately half of the abstracts accepted for presentation are by authors representing nearly 30 European and Asian countries. The setting for the technical and social activities of PPC2009 is the Renaissance Mayflower Hotel, a historic site in the heart of downtown Washington. The Mayflower is routinely frequented by celebrities, international royalty, and diplomats, because of its atmosphere and access to the corridors of power. President Truman coined this stately property “D.C.’s second best address” when he lived there for the first 90 days of his presidency. The Conference Banquet will be held Wednesday evening in the magnificent Grand Ballroom, the setting of inaugural balls for every U.S. President since the days of Calvin Coolidge. As the U.S. national capital, the District of Columbia is a vibrant city filled with opportunities to explore grand government buildings, monuments, memorials, museums, art, theatre, music, culture, nightlife, and more. The National Mall, a focal point for many visitors, is within easy walking distance or subway ride from the Mayflower. Lined on all sides with many of the most popular destinations of interest, here you’ll find the regal U.S. Capitol building with its newly opened 600,000 sq. ft. Visitor Center, a host of Smithsonian museums, and well-recognized monuments, including the Washington, the Lincoln, and the Jefferson Memorials. We will be providing a free shuttle on Monday for attendees and companions to explore the sights in and around the Mall. In addition to a great venue, the conference will feature a varied technical program which offers a unique opportunity for IEEE members and non-members alike to learn more about the technology and science that underpins many of the world’s large science machines. We have over 400 oral and poster presentations scheduled in the program, addressing a wide variety of subjects that are often unique to the Pulsed Power Community: dielectrics and energy storage, charged particle beams and sources, high voltage switches and components, and many more. The conference will begin with early registration check-in and a reception on Sunday evening, June 28th. The technical sessions of the conference begin Monday morning with two plenary speakers, followed by three pairs of oral
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sessions scheduled throughout the rest of the day. Tuesday’s activities will follow a similar schedule. On both Monday and Tuesday an exhibitor program will be displayed in parallel with the oral sessions. A reception to highlight our exhibitors will be held Monday evening. Wednesday and Thursday will follow a slightly different format. On both days we will start the day with a plenary talk given by one of the PPS&T Committee award winners, followed by a mix of oral and poster sessions the rest of the day. PPC2009 is supported in significant measure by government and corporate sponsors, and by the participation of exhibitors who provide not only financial support but display components and services that are particularly relevant to the attendees and their needs. I hope you will take a moment to express your appreciation to our sponsors and visit the vendor booths on Monday and Tuesday to explore what they have to offer. I would like to gratefully acknowledge the guidance of the many PPS&T committee members who collectively and individually provided words of wisdom and advice to navigate the many issues in preparing for this conference. I would also like to express my sincere appreciation to the Conference Organizing Committee and the Technical Program Committee for their tireless efforts, as well as staff members of the IEEE Meeting and Conference Management team, the Naval Surface Warfare Center Dahlgren Division, and the University of Missouri - Columbia who helped make this meeting possible. The 18th Pulsed Power Conference will be held in Chicago, Illinois in 2011. Dr. Randy Curry, who has done an outstanding job in assembling the technical program for PPC2009, will be the general chair. I encourage you to provide feedback to the PPS&T committee on your PPC2009 experience to help make future conferences even better. It has been my pleasure and privilege to serve the Pulsed Power Community as your chair for this 17th meeting. Thank you for your attendance and contributions. I hope you will find the experience both professionally rewarding and personally memorable. Frank E. Peterkin, Ph.D. PPC2009, Chair
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PPC2009 COMMITTEE CHAIRS AND STAFF General Conference Chair Frank Peterkin, Naval Surface Warfare Center – Dahlgren Technical Program/Publication Chair Randy Curry, University of Missouri - Columbia Conference Treasurer Matt McQuage, Naval Surface Warfare Center – Dahlgren Conference Coordinator Keisha Hersey, IEEE Meeting and Conference Management Sponsor Chair Tom Hussey, Air Force Office of Scientific Research Professional Awards Chair Peter Turchi, Los Alamos National Laboratory Student Travel Grants Chair Frank Hegeler, Naval Research Laboratory Companion Program Chair Barb Hussey Visa Assistance Ken Struve, Sandia National Laboratories Webmaster Tanys Nelson, University of Missouri - Columbia Abstract and Paper Submission Bo Yu, Brookhaven National Laboratory Staff Assistants Stacey Woodard, Naval Surface Warfare Center – Dahlgren Linda Macon, University of Missouri - Columbia Kristy Breid, University of Missouri – Columbia
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PPC2009 TECHNICAL PROGRAM COMMITTEE MEMBERS
Randy Curry (Chair) University of Missouri - Columbia Susan Heidger Air Force Research Laboratory - Kirtland Don Sullivan Ktech Corp. Ken Struve Sandia National Laboratories Ray Scarpetti Los Alamos National Laboratory Stuart Moran Naval Surface Warfare Center - Dahlgren David Price L-3 Communications, Pulse Sciences Bryan Oliver Sandia National Laboratories Mark Crawford Institute for Advanced Technology Larry Altgilbers Army Space and Missile Defense Command Bruce Weber Naval Research Laboratory Robert O’Connell University of Missouri - Columbia
PULSED POWER SCIENCE AND TECHNOLOGY COMMITTEE
Edl Schamiloglu (Chair) University of New Mexico Raymond Allen Naval Research Laboratory Larry Altgilbers Army Space and Missile Defense Command Pat Corcoran L-3 Communications, Pulsed Sciences Mark Crawford Institute for Advanced Technology Randy Curry University of Missouri - Columbia James Degnan Air Force Research Laboratory - Kirtland Charles Gilman Science Applications Inc. Mark Henderson Naval Air Warfare Center - China Lake Thomas Hussey Air Force Office of Scientific Research Juergen Kolb Old Dominion University John Maenchen Sandia National Laboratories Andreas Neuber Texas Tech University Bryan Oliver Sandia National Laboratories Frank Peterkin Naval Surface Warfare Center – Dahlgren David Price L-3 Communications, Pulse Sciences Mark Rader Army Space and Missile Defense Command Rick Spielman Ktech Corp. Peter Turchi Los Alamos National Laboratory
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ORAL SESSION CHAIRS Benjamin Prichard Los Alamos National Laboratory Andreas Neuber Texas Tech University Donald Sullivan Ktech Corp. Bruce Freeman Ktech Corp. Robert Reinovsky Los Alamos National Laboratory Matthew Domonkos Air Force Research Laboratory - Kirtland David Johnson L-3 Communications, Pulse Sciences Allen Stults Aviation & Missile Research D & E Laboratory Mark Rader Army Space and Missile Defense Command Michael Mazarakis Sandia National Laboratories Thomas Hughes Voss Scientific Matt McQuage Naval Surface Warfare Center – Dahlgren Jack Bernardes Naval Surface Warfare Center – Dahlgren Tim Andreadis Naval Research Laboratory Susan Heidger Air Force Research Laboratory - Kirtland David Wetz University of Texas at Austin Timothy Renk Sandia National Laboratories Dwayne Surls University of Texas at Austin Paul Armistead Office of Naval Research Richard Ness Ness Engineering Dan Schweickart Air Force Research Laboratory – Wright Patterson Naz Islam University of Missouri - Columbia Mike Kempkes Diversified Technologies, Inc. Jacob Walker Naval Surface Warfare Center – Dahlgren
POSTER SESSION CHAIRS Peter Duselis Ktech Corp. Dianne Loree Air Force Research Laboratory - Kirtland Mike Ong Lawrence Livermore National Laboratory Kim Morales Naval Surface Warfare Center – Dahlgren Keith LeChien Sandia National Laboratories Aaron Dougherty Naval Research Laboratory Zac Shotts Radiance Technology Donald Murphy Naval Research Laboratory Joshua Leckbee Sandia National Laboratories James Dickens Texas Tech University
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Pulsed Power Conference 2009
Conference Supporters and Sponsors
The Pulsed Power Science and Technology Committee of the IEEE Nuclear and Plasma Sciences Society
Also supported by:
Air Force Office of Scientific Research Defense Threat Reduction Agency
Department of Energy Ktech Corporation
L-3 Communications Lawrence Livermore National Laboratory
Lockheed Martin Naval Research Laboratory Office of Naval Research
Sandia National Laboratories SAIC
Exhibitors
ABB Semiconductors
Applied Energetics, Inc. Barth Electronics, Inc.
Diversified Technologies, Inc. General Atomics
HV Components/CKE HVR Advanced Power Components
Kumamoto University Powerex, Inc.
Pulsed Technologies, Ltd. SBE, Inc.
Silicon Power Corp. Stangenes Industries, Inc. TDK-Lambda High Power
Tech-X Corporation UltraVolt, Inc.
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18th International Pulsed Power Conference
Chicago, Illinois June 19-24, 2011 Hyatt Regency, McCormick Place
Co-located with ICOPS/SOFE June 26-30, 2011
Chair: Dr. Randy D. Curry University of Missouri [email protected]
Technical Program Chair:
Dr. Bryan V. Oliver Sandia National Laboratories
ppc.missouri.edu
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Previous Pulsed Power Conferences
1976 Lubbock, TX T.R. Burkes, M. Kristiansen
1976 Lubbock, TX A.H. Guenther, M. Kristiansen
1981 Albuquerque, NM T.H. Martin, A.H. Guenther
1983 Albuquerque, NM T.H. Martin, M.F. Rose
1985 Arlington, VA M.F. Rose, P.J. Turchi
1987 Arlington, VA P.J. Turchi, B.H. Bernstein
1989 Monterey, CA B.H. Bernstein, J.P. Shannon
1991 San Diego, CA R. White, K. Prestwich
1993 Albuquerque, NM K. Prestwich, W. Baker
1995 Albuquerque, NM W. Baker, G. Cooperstein
1997 Baltimore, MD G. Cooperstein, I. Vitkovitsky
1999 Monterey, CA C. Stallings, H. Kirbie
2001 Las Vegas, NV R.E. Reinovsky, M.A. Newton
2003 Dallas, TX M. Glesselmann, A. Neuber
2005 Monterey, CA J.E. Maenchen, E. Schamiloglu
2007 Albuquerque, NM E. Schamiloglu, F. Peterkin
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Conference Location Conference Location
The conference hotel, which also serves as the venue for all technical sessions, is the Renaissance Mayflower Hotel in downtown Washington DC. Situated in the heart of the business district within several city blocks of the White House and the National Mall, this historic hotel in Dupont Circle offers an elegant and historic aura combined with an abundance of modern conveniences courtesy of a recent $11 million luxury
restoration project. Conference attendees and their guests may dine at the hotel's newly renovated Cafe Promenade & Lounge, or enjoy the close proximity to dozens of restaurants within easy walking distance. Also nearby are many major attractions such as national monuments, internationally renowned museums, and major federal government facilities.
About DC About DC
In Washington, DC, you’ll enjoy access to fascinating, FREE attractions and historic sights. Touch a moon rock, marvel at the Hope Diamond, view Dorothy’s Ruby Red slippers or explore Native American culture at the Smithsonian Institution’s fifteen Washington, DC area facilities. Discover treasures like the Gutenberg Bible at the Library of Congress, the only da Vinci painting in North America at the National Gallery of Art and historic documents like the Declaration of Independence at the National Archives. Away from these celebrated federal sites, Washington, DC unwinds into a fascinating network of neighborhoods where visitors discover trendy boutiques, hip bars and restaurants, plus art galleries, historic homes and lush parks and gardens. Shoppers love the store-lined streets of Georgetown, while jazz music fans won’t want to miss a trip to U Street, where Duke Ellington played his first notes. The city’s
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international character shines through in its Adams Morgan and Dupont Circle neighborhoods, two prime destinations for eclectic dining and nightlife and the historic center of the city’s embassy community. The arrival of several new eateries has made the nation’s capital a prime destination for dining out, with many of the city’s top tables located in the downtown Penn Quarter neighborhood. DC is also earning new recognition as a thriving performing arts town, with 65 professional theatre companies based in the metropolitan area presenting edgy world premieres and celebrated Broadway musicals throughout the year.
Conference Format Conference Format
The conference will include plenary, oral, and poster sessions. One plenary presentation will be an address by the 2009 IEEE NPSS Erwin Marx Award recipient; another address will be given by the 2009 IEEE NPSS Peter Haas Pulsed Power Award recipient; and another will be an address by the 2009 IEEE NPSS Plasma Science and Applications Award recipient. Oral presentations will include both invited and contributed papers. Invited talks will be 30 minutes and contributed talks 15 minutes including five minutes for questions. Oral presentations will be delivered using a computer and LCD projector. The expected applications are Microsoft Powerpoint and Adobe Acrobat (pdf files). Presentations are to be submitted on a CD or flash memory and will be transferred to the database at registration.
Student Travel Grant Student Travel Grant
A limited number of travel grants, typically $750, were available to encourage graduate IEEE members to attend PPC-2009. Applicants were required to submit the following information by 15 April 2009. • Copy of submitted abstract • IEEE membership number •Social security number (for US participants only) • Proposed travel budget to the conference (cost sharing with other students is encouraged) • Two letters of recommendation, one of which is from the student’s advisor, stating research to be presented.
Chair of the Student Travel Grant Committee:
Dr. Frank Hegeler [email protected]
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IEEE Arthur H. Guenther Pulsed Power Student Award
IEEE Arthur H. Guenther Pulsed Power Student
Award
IEEE Arthur H. Guenther Pulsed Power Student Award
The IEEE NPSS Pulsed Power Science and Technology Committee's Outstanding Pulsed Power Student Award was established in 1997. In 2007 this award was renamed the Arthur H. Guenther Pulsed Power Student Award following the passing of the former Peter Haas award recipient. It is offered annually, but presented biennially at the Pulsed Power Conference. This award is designed to encourage student contributions and participation as principal or sole authors of papers and to recognize outstanding student contributions in pulsed power engineering, science or technology. In order to be eligible for an award, the student must fulfill the following three eligibility criteria: 1) The student must be the first author of the paper or poster and must have performed the majority of the work. 2) The work must be original. And 3) The student must receive endorsement from her/his graduate advisor. The evaluation committee will review the eligible abstracts and down-select up to 8 abstracts for presentation before the committee at the conference. Complete instructions will be provided to the finalists once their abstracts have been selected. Selection criteria of presentations will be based on the quality of the work as well as the student’s grasp of the subject matter and his/her ability to communicate clearly. A $1,000 and a certificate will be granted to the winner.
For information contact: Dr. Peter J. Turchi [email protected].
Registration Fees Registration Fees
Notes The registration fee for non-members includes a free six-month membership in the IEEE. See below. Affiliate members of the IEEE Nuclear and Plasma Science Society (NPSS) qualify for the lower Members rate. For membership information, contact IEEE Member Services at 800-678-IEEE. Free Introductory IEEE Membership In order to encourage participation in the activities of the IEEE and the Pulsed Power Science and Technology and Plasma Science and Applications Committees of the IEEE Nuclear and Plasma Science Society, free half-year memberships will be given to all interested non-IEEE members (including students) registering for this conference. This free half-year membership includes a subscription to IEEE Spectrum and Transactions
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on Plasma Science. The regular cost of a full year’s membership can be found at www.ieee.org. Membership includes: 1. Subscription to Transactions on Plasma Science, a journal devoted to all aspects of plasma science and technology. 2. Subscription to IEEE Spectrum, a magazine covering engineering topics of general technical, economic, political, and social interest. 3. Subscription to the NPSS Newsletter with news items about the Pulsed Power Conference, Conference on Plasma Science, and the Symposium on Fusion Engineering. 4. Eligibility to participate in a broad range of IEEE activities. 5. Opportunities for IEEE educational services such as video-conferences and individual learning packages. To receive our free membership, fill out an application at the Registration Desk or call 800-678-IEEE.
Registration
Registration
Advance Registration Advance registration is highly recommended. Register in full (including payment of the registration fee) by 15 May 2009 to qualify for the lower advance registration fee. Advance registration can be carried out online at the conference website. The online registration facility will be activated by January 2009. Registration on-site There will be a Registration Desk at the Conference for attendees who have not registered in advance. The Registration Desk will be open on Sunday 28 June from 3 pm-7 pm. On Monday 29 June it will open at 7:00 am, and Tuesday 30 June through Thursday 2 July, it will open at 8:00 am.
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Publications Publications All PPC2009 abstracts appear in this Conference booklet only. Authors of papers presented at the conference are expected to submit manuscripts for inclusion in the published IEEE Proceedings of the 17th International Pulsed Power Conference. Manuscripts from oral and poster presentations may be up to six pages in length. Invited authors may contribute papers up to eight pages in length, and plenary speakers may submit manuscripts up to ten pages. In addition, all authors from PPC2009 are encouraged to consider contributing to a Special Pulsed Power Issue of the IEEE Transactions on Plasma Science (TPS) planned to be published in October 2010. The submission deadline for this issue is expected to be 30 September 2009. Please note that authors of papers presented at PPC2009 which might not be appropriate for the Special Issue are encouraged to submit their manuscripts to a regular issue of the Transactions on Plasma Science. Information about the Transactions and links to the Manuscript Central manuscript submission portal may be found on the TPS website at http://www.ieeetps.org. Any questions about the Transactions, submissions, etc. should be directed to the Editor, Dr. Steven J. Gitomer ([email protected]).
Job Placement Center Job Placement Center
Continuing the tradition from recent Pulsed Power Conferences a job placement center will be setup at PPC2009. Individuals interested in employment opportunities in pulsed power, plasma science, and related areas should mail a resume or vitae to:
PPC2009 Job Placement Center PO Box 1570 Dahlgren, Virginia 22448-5161
Alternatively, email an electronic copy to [email protected]. Please use the PDF or Microsoft Word format and put “PPC2009 Job Placement” in the subject line of the email message.
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SOCIAL EVENTS AND COMPANION ACTIVITIES
SOCIAL EVENTS AND COMPANION ACTIVITIES
Social Events
• Welcome Reception on Sunday, 28 June in parallel with the opening of conference registration.
• Exhibitor’s Reception with light hors d’oeuvres the evening of Monday, 29 June. Please take the time to browse our exhibitor booths and thank them for their financial support to the conference.
• The Conference Banquet will be held Wednesday evening, 1 July in the beautiful and historic Grand Ballroom. As was done in 2007, attendance at the banquet is NOT included in the general registration fee for the conference. To help us better plan for actual banquet participation, banquet attendance requires payment of a nominal $15 fee for early registrants or $25 for on-site registrants.
MONDAY, JUNE 29, 2009EVENT: THE SMITHSONIAN SHUTTLE DATE: MONDAY, JUNE 29, 2009 TIME: 9:30AM – 5:30PM
Aerial view of the National Mall in Washington, D.C. Photo courtesy of the National Park ServicePROGRAM DESCRIPTION:
Guests will welcome the convenience of their private shuttle to the Smithsonian Museums that line the National Mall. During their trip to the Mall, a professional, uniformed tour guide will provide an overview of the various Smithsonian Museums and their current special exhibits. Guests will have door to door service
to the following Museum’s: • African Art Museum • Air & Space Museum • American History Museum • American Indian Museum • Arts & Industries Building • Freer Gallery • Arthur M. Sackler Gallery • Hirshhorn Museum and Sculpture Garden • Natural History Museum • National Gallery of Art Smithsonian Institution Building, "The Castle"
Photo courtesy of the Smithsonian
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The coach will depart the hotel for the National Mall on the following schedule: 9:30am, 10:30am, 11:30am, 1:00pm, 2:00pm, 3:00pm and 4:00pm. Return service back to the Mayflower Hotel will be offered from the Smithsonian Castle Informational Center on the following schedule: 10:15am, 11:15am, 12:30pm, 1:45pm, 2:45pm, 3:45pm, and 5:00pm. TUESDAY, JUNE 30, 2009
EVENT: UNDERCOVER CAPITAL ~ THE SPIES OF WASHINGTON, D.C. WITH LUNCH AT CHADWICK’S IN GEORGETOWN DATE: TUESDAY, JUNE 30, 2009 TIME: 9:00AM – 3:00PM Lunch is included
PROGRAM DESCRIPTION: Washington, D.C. has long been famous for two hundred years as the scene of the political dealmaking, of political maneuvering, of political gamesmanship, and also acts of great political courage and distinction. Lesser known are the acts of espionage that have occurred in the very shadows of our nation’s capitol. In this all encompassing riding tour, under the guide of U.S. Air Force Intelligence Officer and Vietnam Veteran, Carol Besette, guests will learn little known secrets including the connection Capitol Hill has with spying activities of over four hundred years ago. Guests will see the offices and homes of some of the most famous Hill residents (some of whom not usually associated with espionage), and learn little known spy stories about some of the most famous buildings and faces in Washington.
Russian Embassy
They will explore the neighborhoods around the present Russian Embassy on Upper Wisconsin Avenue learning a rich history of espionage involving well-
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known and little known personalities, embassies, apartments, and restaurants of the area, and even of the revered Washington National Cathedral! They will uncover who was the Confederate spy who practiced her wiles in the shadow of the White House. Guests will also unveil the motivation of the FBI counterintelligence agent who provided information to the Soviets at the same time that he worked to capture Soviets spies and whether there really was a link between Jacqueline Kennedy Onassis and the famous Cambridge Five group of spies. Guests will take a respite for lunch at Chadwick’s in Georgetown. Located on K Street, Chadwick’s was often used as a drop point by one of the most damaging spies in U.S. history, Aldridge Ames. Guests will be seated in the upstairs dining room. By special arrangement, through Capital City Events, Inc. guests will have a personal briefing with Gary Powers, founder of the Cold War Museum and son of CIA Intelligence officer and U2 pilot, Francis Gary Powers, shot down over Russia in 1960.
WEDNESDAY, JULY 1, 2009 EVENT: NEWSEUM ~ THE INTERACTIVE MUSEUM OF NEWS DATE: WEDNESDAY, JULY 1, 2009 TIME: 9:00AM – 1:00PM PROGRAM DESCRIPTION:
Newseum building complex James P. Blair/Newseum
Today, guests will travel to one of the newest museum in the nation’s capital, the
Newseum, the interactive museum of news. Open to the public in April 2008, the 250,000 square foot museum offers guests five centuries of news history with up-to-the- second technology and hands-on exhibits. Escorted by your licensed Capital City Events tour guide, guests will visit the Great Hall of News where they will be surrounded by a continuous flow of breaking news as well as historic clips. The Halls’ soaring, 90-foot-high atrium also showcases modern news gathering and transmission icons. News breaks, and a deadline is looming. Can you prepare a complete, timely and accurate report? The Interactive Newsroom gives guests a chance to play the role of a reporter or photographer. Here, touch-screen stations
provide the reporting tools and techniques needed. There are also eight "Be a Reporter" stations where guests can pick up a microphone, step before a camera and experience what it's like to be the next Diane Sawyer or Anderson Cooper.
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Guests will also have the opportunity to visit the 911 Gallery, which chronicles the events of September 11, 2001 and pays tribute to photojournalist William Biggart, a journalist who died covering the attacks. Also featured are front pages from around the globe about the attacks and first-person accounts from reporters and photographers who covered the story. Among many other exhibits, the Newseum also features the most comprehensive collection of Pulitzer Prize-winning photographs ever assembled including the Marines raising Old Glory on Iwo Jima, the joyful reunion of a returning POW and his family, and a firefighter cradling an injured infant after the Oklahoma City bombing. Lastly, soaring above Pennsylvania Avenue, guests will have the opportunity to visit America’s Main Street encompassing landmarks and monuments of American history, including the U.S. Capitol, the National Gallery of Art, the National Archives and the Washington Monument.
NEWSEUM EXHIBITS AND THEATERS
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TECHNICAL SESSIONS
Monday June 29 10:00 - 12:00 Colonial Oral Sessions Session Chair: Benjamin A. Prichard Los Alamos National Laboratory Session O1: E-Beam Driven X-ray Sources
O1-1 Characterization of the Rod-Pinch Diode X-Ray Source on Cygnus B. V. Oliver1, G. Cooperstein2, S. R. Cordova1, D. Crain3, D. Droemer3, T. Haines4, D. Hinshelwood2, N. King4, S. Lutz3, C. L. Miller5, I. Molina1, D. Mosher6, D. Nelson1, E. Ormond1, S. Portillo7, J. Smith4, D. Welch5, W. M. Wood4 1Sandia National Laboratories, Albuquerque, NM, United States 2Naval Research Laboratory, Washington, DC, United States 3National Securities Technologies, LLC, Las Vegas, NV, United States 4Los Alamos National Laboratories, Los Alamos, NM, United States 5Voss Scientific, LLC, Albuquerque, NV, United States 6L-3 Pulse Sciences, San Leandro, CA, United States 7Ktech Corp., Albuquerque, NM, United States
O1-2 Cygnus Dose Symmetry* E. C. Ormond1, D. S. Nelson1, S. R. Cordova2, I. Molina2, J. R. Smith3, E. A. Rose3, R. E. Gignac4, D. E. Good4, M. D. Hansen4, D. J. Henderson4, C. V. Mitton4, S. S. Lutz4 11649-1, Sandia National Laboratories, Mercury, NV, United States 21645, Sandia National Laboratories, Albuquerque, NM, United States 3Los Alamos National Laboratory, Los Alamos, NM, United States 4National Security Technologies, Las Vegas, NV, United States
O1-3 Detailed Simulation of the CYGNUS Rod Pinch Radiographic Source C. L. Miller1, D. R. Welch1, D. V. Rose1, B. V. Oliver2
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1Voss Scientific, LLC, Albuquerque, NM, USA 2Sandia National Laboratories, Albuquerque, NM, USA
O1-4 X-Ray Absorption and Scattering Issues for Rod-Pinch Radiographic Sources* D. Mosher1, D. D. Hinshelwood2, G. Cooperstein2, B. Huhman2, R. J. Allen2, S. S. Lutz3, M. J. Berninger3, B. V. Oliver4, S. Portillo5, T. Haines6 1L-3 Communications, Reston, VA, United States 2Naval Research Laboratory, Washington, DC, United States 3National Security Technologies, North Las Vegas, NV, United States 4Sandia National Laboratories, Albuquerque, NM, United States 5Ktech Corporation, Albuquerque, NM, United States 6Los Alamos National Laboratory, Los Alamos, NM, United States
O1-5 Status of Self-Magnetic Pinch Diode Investigations on RITS-6* K. Hahn1, B. V. Oliver1, S. R. Cordova1, J. Leckbee1, I. Molina1, M. Johnston1, T. Webb1, N. Bruner2, D. V. Rose2, D. R. Welch2, S. Portillo3, D. Ziska3, S. Clough4, A. Critchley4, I. Crotch4, A. Heathcote4, A. Jones4, J. Threadgold4 1Sandia National Labs, Albuquerque, NM, United States 2Voss Scientific, Albuquerque, NM, United States 3KTech Corporation, Albuquerque, NM, United States 4Atomic Weapons Establishment, Reading, Berkshire, United Kingdom
O1-6 Plasma Dynamics in Relativistic Electron Beam Diodes for Flash X-Ray Radiography M. D. Johnston1, B. V. Oliver1, S. Portillo1, D. R. Welch2, D. W. Droemer3 1Sandia National Laboratories, Albuquerque, NM, United States 2Voss Scientific, LLC, Albuquerque, NM, United States 3National Security Technologies, LLC, Las Vegas, NV, United States
O1-7 Comparisons of the Self Pinch Diode and Paraxial Diode Electron Distributions at the Conversion Target Using LSP P. N. Martin, S. Vickers AWE, Aldermaston, United Kingdom
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Monday June 29 10:00 - 12:00 Ballroom Session Chair: Andreas A. Neuber TTU, Pulsed Power Laboratory Session O2: Compact Pulsed Power O2-1 Study of Hybrid Nonlinear Transmission Lines for High Power
RF Generation J. O. Rossi, P. N. Rizzo Associated Plasma Laboratory, National Institute for Space Research -INPE, S.J. Campos, SP, Brazil
O2-2 A 250kV-300ps-350Hz Marx Generator as Source for a UWB Radiation System L. Pecastaing1, B. Cadilhon1, T. Reess1, A. De Ferron1, P. Pignolet1, S. Vauchamp2, J. Andrieu2, M. Lalande2, J. -P. Brasile3 1Laboratoire de Genie Electrique - UPPA, Pau, France 2XLIM OSA, Brive, France 3Thales Communisations, Colombes, France
O2-3 Development of Miniature Marx Generator Using BJT M. Inokuchi1, T. Ueno2, M. Akiyama1, T. Sakugawa1, H. Akiyama1 1Graduate School of Science and Technology Kumamoto University, Kumamoto, Japan 2Oita National College of Technology, Oita, Japan
O2-4 0.5MJ 18kV Module of Capacitive Energy Storage B. E. Fridman, R. S. Enikeev, N. A. Kovrizhnykh, K. M. Lobanov, R. A. Serebrov STC "SINTEZ", D.V. Efremov Scientific Research Institute of Electrophysical Apparatus, St.-Petersburg, Russian Federation
O2-5 Development of a Compact X-pinch Driver with Single Cap-Single Switch Design. First Results for Radiography of Wire Array Experiments within Sphinx Project A. Loyen, F. Lassalle, P. Maury, A. Morell, H. Calamy, P. Combes, A. Georges Exnam, Centre d'ETudes de Gramat, Gramat, France
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O2-6 Development of 150kJ Compact Pulsed Power System for ETC Accelerator B. H. Lee, J. S. Kim, S. H. Kim, K. S. Yang The 4th R&D Institute-1, ADD, Daejeon, South Korea
O2-7 Nano- and Picosecond Pulse Generators Based on FID Technology V. M. Efanov, M. V. Efanov, A. V. Kriklenko, P. M. Yarin, A. V. Komashko, A. A. Arbuzov FID GmbH, Burbach, Germany
O2-8 High-Power, Compact and Repetitive Driver for Pulsed Electron Beam Generation R. Shukla, P. Deb, S. K. Sharma, A. Shyam, P. Banerjee, T. Prabahar, B. Adhikary, K. G. Shah E&ED, BARC, Mumbai, India
Monday June 29 13:00 - 14:30 Ballroom Session Chairs: Donald Sullivan Ktech Corp. Bruce Freeman Ktech Corp. Session O3: Narrow Band and Electron Devices O3-1 Generation of Sub-GW-Level RF Pulses in Nonlinear
Transmission Lines V. V. Rostov, N. M. Bykov, D. N. Bykov, A. V. Gunin, A. I. Klimov, V. O. Kutenkov, I. V. Romanchenko High Current Electronics Institute, Tomsk, Russian Federation
O3-2 High Efficiency Relativistic Magnetron with Diffraction Output M. I. Fuks, E. Schamiloglu Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, NM, USA
O3-3 Experimental Verification of the Theory of the Transparent Cathode S. Prasad, J. Buchenauer, M. Fuks, E. Schamiloglu
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Electrical and Computer Eng., University of New Mexico, Albuquerque, United States
O3-4 Experimental Studies of the Influence of a Resonance Cavity in an Axial Vircator C. Möller, M. Elfsberg, A. Larsson, S. E. Nyholm Defence & Security, Systems and Technology, Swedish Defence Research Agency (FOI), Stockholm, Sweden
O3-5 Relativistic Magnetron Operation with Explosive Emission and Ferroelectric Plasma Source Cathodes Y. Hadas, A. Sayapin, T. Kweller, Y. E. Krasik Physics dep., Technion-Israel Institute of Technology, Haifa, Israel
O3-6 New Configuration of Virtual Cathode Oscillator W. Jiang Tsinghua University, Beijing, China
Monday June 29 13:00 - 14:30 Colonial Session Chair: Robert E. Reinovsky Los Alamos National Laboratory Session O4: High Energy Density Plasmas – Z Pinches O4-1 Innovative Long Implosion Time Plasma Radiation Sources
H. Calamy1, F. Zucchini1, A. Loyen1, F. Lassalle1, P. Combes1, S. Ritter1, J. F. Cambonie1, B. Roques1, S. Bland2, N. Niasse2 1Centre d'Etudes de Gramat, Gramat, France 2Blackett Laboratory, Imperial Collega, London, UK
O4-2 Plasma Streaming Across Magnetic Field
R. Presura, C. Plechaty, Y. Sentoku, S. Wright, D. Martinez, S. Neff, V. V. Ivanov, Y. Stepanenko University of Nevada, Reno, Nevada 89557, United States
O4-3 Numerical Simulations of Thick Aluminum Wire Behavior under Megaampere Current Drive* S. F. Garanin1, S. D. Kuznetsov1, W. L. Atchison2, R. E. Reinovsky2, A. J. Awe3, B. S. Bauer3, S. Fuelling3, I. R. Lindemuth3, R. E. Siemon3
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1All-Rusiian Research Institute of Experimental Physics (VNIIEF), Sarov, Russian Federation 2LANL, Los Alamos, New Mexico, USA 3University of Nevada, Reno, Nevada, USA
O4-4 Current Implosion of Quasi-Spherical Wire Arrays E. V. Grabovski1, A. N. Gritsouk1, V. V. Aleksandrov1, V. P. Smirnov2, P. V. Sasorov3, V. V. Fedulov1, I. N. Frolov1, Y. N. Laukhin1, A. N. Gribov1, S. F. Medovshikov1, K. N. Mitrofanov1, G. M. Oleinik1, A. A. Samokhin1, G. S. Volkov1, V. I. Zaitsev1 1SRC RF TRINITI, Troitsk, Russian Federation 2Kurchatov Institute, Moscow, Russian Federation 3ITEP, Moscow, Russian Federation
O4-5 Trailing and Lost Mass in Z-Pinch Experiment on Angara-5-1 Facility G. Oleynik TRINITI, Troitsk, Russian Federation
O4-6 X-Ray Backlighting for Early Stages of Wire Array Z-Pinches Using an X-Pinch T. Zhao, X. Zou, X. Wang, Y. Zhao, Y. Du Department of Electrical Engineering, Tsinghua University, Beijing, China
Monday June 29 15:00 - 17:00 Ballroom Session Chair: Diana Loree Air Force Research Laboratory Session O5: RF/HPM Systems and Effects O5-1 History and Hardware behind the Active Denial Technology
Capability D. L. Loree Directed Energy Directorate, Air Force Research Laboratory, Kirtland AFB, NM, United States
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O5-2 WBTS HPM a Transportable High-Power Wide-Band Microwave Source D. Morton1, J. Banister1, T. DaSilva1, J. Levine1, T. Naff1, I. Smith1, H. Sze1, T. Warren1, D. Giri2, C. Mora3, J. Pavlinko3, J. Schleher3, C. Baum4 1L3 Pulse Sciences, San Leandro, CA, United States 2Pro-Tech, CA, United States 3SAIC, ABQ, NM, United States 4University of New Mexico, NM, United States
O5-3 High Power Pulse Burst Generation by Solitons-Type
Oscillation on Nonlinear Lumped Element Transmission Lines J. D. C. Darling, P. W. Smith Dept. of Engineering Science, University of Oxford, Oxford, United Kingdom
O5-4 All-Solid-State 13.56 MHz RF Sources with 20 kW Power
V. M. Efanov, P. M. Yarin, A. V. Kriklenko FID GmbH, Burbach, Germany
O5-5 Use of Radiation Sources to Provide Seed Electrons in High
Power Microwave Surface Flashover* M. Thomas, J. Foster, H. Krompholz, A. Neuber Center for Pulsed Power and Power Electronics, Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, TX, United States
O5-6 Short Pulse High Power Microwave Surface Flashover
J. T. Krile, L. M. McQuage, J. Walter, J. Dickens, A. A. Neuber Center for Pulsed Power and Power Electronics, Texas Tech University, Lubbock, TX, United States
O5-7 Performance of a Compact Triode Vircator and Marx Generator
System J. W. Walter, J. C. Dickens, M. Kristiansen Center for Pulsed Power and Power Electronics, Texas Tech University, Lubbock, TX, United States
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Monday June 29 15:00 - 17:00 Colonial Session Chair: David L. Johnson L-3 Communications/Pulse Sciences Session O6: Pulsed Power Sources – High Current
Accelerators
O6-1 Linear Transformer Driver (LTD) Development at Sandia
National Laboratory M. G. Mazarakis1, S. Cordova1, R. G. Gilgenbach2, D. L. Johnson3, A. A. Kim4, K. J. LeChien1, J. J. Leckbee1, F. W. Long1, M. K. Matzen1, R. G. McKee1, J. L. McKenney1, B. V. Oliver1, J. L. Porter1, V. A. Sinebryukhov4, W. A. Stygar1, D. M. VanDevalde5, K. Ward6, J. W. Weed1, J. R. Woodworth1 1Sandia National Laboratories, Albuquerque, NM, United States 2University of Michigan, Ann Arbor, MI, United States 3L3 Communications - Pulse Sciences, San Leandro, CA, United States 4High Current Electronic Institute, Tomsk, Russia 5EG&G, Albuquerque, NM, EG&G 6Ktech Corporation, Albuquerque, NM, United States
O6-2 Positive-Polarity Power Flow in Multiple-Adder MITLs* J. W. Schumer, P. F. Ottinger, R. J. Allen, D. D. Hinshelwood, S. B. Swanekamp Plasma Physics Division, Naval Research Laboratory, Washington, DC, United States
O6-3 Conceptual Designs for an Upgrade of the Sphinx Z-Pinch Driver F. Lassalle, A. Georges, B. Roques, H. Calamy, A. Loyen Centre d'Etudes de Gramat, Gramat, France
O6-4 Polarity Inversion on Saturn V. J. Harper-Slaboszewicz1, K. A. Mikkelson1, B. V. Weber2, D. P. Murphy2, R. J. Commisso2, J. R. Goyer3, J. C. Riordan3 1Sandia National Laboratories, Albuquerque, NM, United States 2Naval Research Laboratory, Washington, DC, United States 3Pulsed Sciences, L3 Communications, San Leandro, CA, United States
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O6-5 Circuit Modeling Techniques Applied to ZR P. A. Corcoran1, B. A. Whitney1, V. L. Bailey1, L. G. Schlitt2, M. E. Seiford3, J. W. Douglas4, M. E. Savage1, W. A. Stygar3, I. D. Smith1 1L-3 Systems /Pulse Sciences, San Leandro, CA, United States 2Leland Schlitt Consulting Services, Estes Park, CO, United States 3Sandia National Laboratory, Albuquerque, NM, United States 4John Douglas Consulting Services, Tucson, AZ, United States
O6-6 Testing of a 1-MV Linear Transformer Driver (LTD) for Radiographic Applications J. J. Leckbee1, S. Cordova1, B. V. Oliver1, D. L. Johnson2, M. Toury3, R. Rosol3, B. Bui4 1Sandia National Laboratories, Albuquerque, NM, United States 2L3 Communications - Pulse Sciences, San Leandro, CA, United States 3CEA-DAM, Polygone d'Experimentation de Moronvilliers, Pontfaverger-Moronvilliers, France 4Ktech Corporation, Albuquerque, NM, United States
O6-7 Design and Tests of Induction Cavity for 3MV IVA Accelerator P. T. Cong, A. C. Qiu, H. L. Yang, F. J. Sun, G. W. Zhang, H. Y. Wu Northwest Institute of Nuclear Technology, Xi'an, China
Tuesday June 30 10:00 - 12:00 Ballroom Session Chairs: Allen H Stults
Aviation and Missile Research Development and Engineering Laboratory Mark S Rader
US Army SMDC Session O7: Explosive Pulsed Power 1 O7-1 Use of Ferroelectric Generators for RF Applications
A. H. Stults WDI, Aviation and Missile Research Development and Engineering Laboratory, Redstone Arsenal, AL, United States
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O7-2 Development of Ferroelectric Materials for Explosively Driven Pulsed Power Systems E. F. Alberta1, W. S. Hackenberger1, B. Freeman2, D. J. Hemmert3, A. H. Stults4, L. L. Altgilbers5 1TRS Technologies Inc., State College, PA, United States 2Ktech Corp., Albuquerque, NM, United States 3HEM Technologies, Lubbock, TX, United States 4U.S. Army AMRDEC, Huntsville, AL, United States 5U.S. Army SMDC, Huntsville, AL, United States
O7-3 Prediction of Compact Explosively-Driven Ferroelectric Generator Performance D. W. Bolyard, A. Neuber, J. Krile, J. Dickens, M. Kristiansen Center for Pulsed Power and Power Electronics, Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, TX, United States
O7-4 Electrical Conduction in Select Polymers under Shock Loading C. F. Lynn, A. Neuber, J. T. Krile, J. Dickens, M. Kristiansen Electrical Engineering, Texas Tech University, Lubbock, TX, United States
O7-5 A Helical Magnetic Flux Compression Generator with a Conical Armature Z. W. Dong, C. Y. Yu, Q. Zhao, X. J. Yang Institute of Applied Physics and Computational Mathematics, Beijing, China
O7-6 Performance of a Compact, Cascade FCG System J. V. Parker1, C. E. Roth1, F. M. Lehr2, S. K. Coffey3, J. H. Degnan2 1Science Applications International Corporation, Albuquerque, NM, United States 2Directed Energy Directorate, Air Force Research Laboratory, Albuquerque, NM, United States 3Numerix, Inc, Albuquerque, NM, United States
O7-7 Ultra-Compact High Efficiency Multi-Kilovolt Pulsed Power Source Z. S. Roberts, Z. D. Shotts, M. F. Rose Radiance Technologies, Huntsville, Alabama, United States
O7-8 Circuit Modeling of a Power Conditioning Circuit with an Electroexplosive Opening Switch K. A. O'Connor, R. D. Curry Center for Physical and Power Electronics, University of Missouri-Columbia, Columbia, MO, United States
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Tuesday June 30 10:00 - 12:00 Colonial Session Chair: Michael G. Mazarakis
Sandia National Laboratories Session O8: High Energy Density Plasmas – Applications O8-1 Numerical Simulation of Metallic Surface Plasma Formation by
Megagauss Magnetic Fields I. R. Lindemuth1, R. E. Siemon1, B. S. Bauer1, M. A. Angelova1, W. L. Atchison2, S. F. Garanin3, V. Makhin4 1University of Nevada, Reno, NV, United States 2Los Alamos National Laboratory, Los Alamos, NM, United States 3All-Russian Institute of Experimental Physics, Sarov, Russia 4NumerEx, Albuquerque, NM, United States
O8-2 Wire Explosion in Vacuum: Velocity of Current-Carrying Corona and Strata Formation R. Baksht1, A. G. Rousskikh2, V. I. Oreshkin2, I. Beilis1 1Tel Aviv University, Tel Aviv, Israel 2Institute of High Current Electronics, Tomsk, Russia
O8-3 Warm Dense Matter: Another Application for Pulsed Power Hydrodynamics R. E. Reinovsky Applied Physics Division, Los Alamos National Laboratory, Los Alamos, NM, United States
O8-4 Effect of External Magnetic Field on Shaped-Charge Operation G. A. Shvetsov1, A. D. Matrosov1, N. N. Marinin1, S. V. Fedorov2, A. B. Babkin2, S. V. Ladov2 1Lavrentyev Institute of Hydrodynamics, Novosibirsk, Russian Federation 2Bauman Moscow State Technical University, Moscow, Russian Federation
O8-5 Explosive Magnetic Liner Devices to Produce Shock Pressures up to 3 TPa A. M. Buyko1, S. F. Garanin1, Y. N. Gorbachev1, G. G. Ivanova1, A. V. Ivanovsky1, I. V. Morozova1, V. N. Mokhov1, A. A. Petrukhin1, V. N. Sofronov1, V. B. Yakubov1, W. L. Atchison2, R. R. Reinovsky2
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1All-Russian Research Institute of Experimental Physics (VNIIEF), Sarov, Russian Federation 2LANL, Los Alamos, New Mexico, USA
O8-6 Pulsatile Behavior of a Helical D.C. Arc in Air at Atmospheric Pressure L. M. Shpanin1, G. R. Jones2, J. W. Spencer2 1Electronic, Electrical and Computer Engineering, University of Birmingham, Birmingham, United Kingdom 2Electrical Engineering and Electronics, University of Liverpool, Liverpool, United Kingdom
O8-7 Advantages of Second-Generation High Temperature
Superconductors for Pulsed Power Applications J. C. Hernandez-Llambes, D. Hazelton Superconducting Devices, Superpower-Inc, Schenectady, United States
Tuesday June 30 13:00 - 14:30 Colonial Session Chair: Thomas Hughes Voss Scientific Session O9: Intense Electron and Ion Beams and Plasmas O9-1 Generation of Ion Beams in Positive Polarity on HERMES III
Operated in a Long-Pulse Mode* T. J. Renk1, V. J. Harper-Slaboszewicz1, K. A. Mikkelson1, J. W. Schumer2, P. F. Ottinger2 1Sandia National Laboratories, Albuquerque, NM, United States 2Naval Research Laboratory, Washington DC, United States
O9-2 High-Voltage, High-Impedance Ion Beam Production from
Extended Cylindrical Diodes D. Hinshelwood1, R. J. Allen1, R. J. Commisso1, G. Cooperstein1, S. L. Jackson2, D. Mosher3, D. P. Murphy1, P. F. Ottinger1, J. W. Schumer1, S. B. Swanekamp3, B. V. Weber1, F. C. Young3 1Plasma Physics Division, US Naval Research Laboratory, Washington, DC, USA 2National Research Council Postdoctoral Research Associate, Washington, DC, USA 3L-3 Communications, Reston, VA, USA
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O9-3 Application of TW-Level Pulsed Power to the Detection of
Fissile Materials* R. J. Commisso1, J. W. Schumer1, F. C. Young2, J. P. Apruzese1, R. J. Allen1, G. Cooperstein1, D. D. Hinshelwood1, S. L. Jackson3, D. Mosher2, D. P. Murphy1, P. F. Ottinger1, S. B. Swanekamp2, S. J. Stephanakis2, B. V. Weber1 1Plasma Physics Division, Naval Research Laboratory, Washington DC, United States 2Titan Group, L-3 Communications, Reston, VA, United States 3NRL National Research Council Research Associate, Washington DC, United States
O9-4 Design of a Compact Coaxial Magnetized Plasma Gun for
Magnetic Bubble Expansion Experiments Y. Zhang1, A. G. Lynn1, S. C. Hsu2, H. Li2, W. Liu2, M. Gilmore1, C. Watts1 1University of New Mexico, Electrical & Computer Engineering Department, Albuquerque, NM, United States 2Los Alamos National Laboratory, Los Alamos, NM, United States
O9-5 LIF Characterization of the Hollow Anode Plasma Ions
V. Vekselman, D. Yarmolich, J. Gleizer, J. Felsteiner, Y. Krasik Physics Department, Technion, Haifa 32000, Israel
O9-6 Supershort Avalanche Electron Beam Generation in Gases
V. F. Tarasenko High Current Electronics Institute, Tomsk, Russian Federation
Tuesday June 30 13:00 - 14:30 Ballroom Session Chair: Matt McQuage Naval Surface Warfare Center Dahlgren Division Session O10: Pulsed Power Switches and Components
Closing Switches
O10-1 Jitter and Recovery Rate of a Triggered Spark Gap with High
Pressure Gas Mixtures Y. J. Chen, J. C. Dickens, J. W. Walter, M. Kristiansen EE, Texas Tech University, Lubbock, United States
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O10-2 Low Inductance Switching Studies for Linear Transformer Drivers W. A. Stygar1, L. F. Bennett1, H. D. Anderson2, J. R. Woodworth1, J. A. Alexander1, M. J. Harden2, J. R. Blickem3, F. R. Gruner4, R. White5 1Dept 1671, Sandia National Laboratories, Albuquerque, New Mexico, United States 2National Security Technologies, Albuquerque, New Mexico, United States 3Ktech Corporation, Albuquerque, New Mexico, United States 4Kinetech LLC, The Dalles, Oregon, United States 5L3 Communications, Pulse Sciences, San Diego, California, United States
O10-3 High Voltage, Flowing Fluid Switch S. L. Heidger1, M. Ruebish2, R. Curry3, D. Shiffler1 1Air Force Research Laboratory, Kirtland AFB, NM, United States 2Sandia National Laboratories, Albuquerque, NM, United States 3University of Missouri-Columbia, Columbia, MO, United States
O10-4 Repetitively Pulsed 1 MV Laser Triggered Gas Switches F. Hegeler1, J. D. Sethian2, M. C. Myers2, A. M. Fielding1, M. F. Wolford2, R. L. Jaynes3, P. M. Burns4, J. L. Giuliani2, M. Friedman1 1Commonwealth Technology, Inc., Alexandria, VA, United States 2Plasma Physics Division, Naval Research Laboratory, Washington, DC, United States 3Science Applications International, Corp., McLean, VA, United States 4Research Support Instruments, Lanham, MD, United States
O10-5 Evaluation of Spark Gap Switches Operated at Low Percent of Self Break Voltage J. M. Lehr1, K. C. Hodge2, S. F. Glover1, G. E. Pena2, L. X. Schneider2 1Exploratory Pulsed Power, Sandia National Laboratories, Albuquerque, NM, United States 2Ktech Corporation, Albuquerque, NM, United States
O10-6 Prospective Pulsed Power Applications of Pseudospark
Switches J. Slough1, C. Pihl1, V. D. Bochkov2, D. V. Bochkov2, P. V. Panov2, I. N. Gnedin2 1Plasma Dynamics Laboratory, University of Washington, Redmond, WA, USA 2Pulsed Technologies Ltd., Ryazan, Russian Federation
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Tuesday June 30 15:00 - 17:00 Ballroom Session Chair: Jack Bernardes
Naval Surface Warfare Center Dahlgren Division Session O11: Pulsed Power Switches and Components –
Solid State Switches O11-1 Wide-Pulse Evaluation of 0.5 cm2 Silicon Carbide SGTO
H. K. O’Brien1, A. Ogunniyi1, W. Shaheen2, C. J. Scozzie1, A. Agarwal3, V. Temple4 1US Army Research Laboratory, Adelphi, MD, United States 2Berkeley Research Associates, Beltsville, MD, United States 3Cree, Inc, Durham, NC, United States 4Silicon Power Corporation, Clifton Park, NY, United States
O11-2 8 kV, 8mm X 8mm SiC SUPER GTO Technology Development for Pulse Power A. K. Agarwal1, C. Capell1, J. Zhang1, R. Callanan1, J. Melcher1, V. Temple2, H. O’Brien3, C. Scozzie3 1SiC Power Device R&D, Cree Inc., Durham, NC, United States 2Commercial Power Division, Silicon Power Corporation, Clifton Park, NY, United States 3AMSRD-ARL-SE-DP, U.S. Army Research Laboratory, Adelphi, MD, United States
O11-3 SiC Based High Voltage Switches - Options in Pulse Power
P. Friedrichs SiCED Electronics Development GmbH & Co. KG, Erlangen, Germany
O11-4 Device Optimization and Performance of 3.5 cm2 Silicon SGTO for Army Applications A. Ogunniyi1, H. O'Brien1, C. Scozzie1, W. Shaheen2, V. Temple3 1US Army Research Laboratory, Adelphi, MD, United States 2Berkeley Research Associate, Beltsville, MD, United States 3Silicon Power Corporation, Clifton Park, NY, United States
O11-5 Analysis of Ultra-Fast Switching Dynamics in a Hybrid MOSFET/Driver T. Tang, C. Burkhart
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Power Conversion Department, Stanford Linear Accelerator Center, Menlo Park, United States
O11-6 Characterization of Power IGBTs under Pulsed Power Conditions J. A. VanGordon1, S. D. Kovaleski1, G. E. Dale2 1Electrical and Computer Engineering, University of Missouri, Columbia, MO, United States 2High Power Electrodynamics Group, Los Alamos National Laboratory, Los Alamos, NM, United States
O11-7 High Voltage Photoconductive Switches Using Semi-Insulating, Vanadium Doped 6H-SiC C. James, C. Hettler, J. Dickens Center for Pulsed Power and Power Electronics, Texas Tech University, Lubbock, TX, United States
O11-8 High-Power Picosecond Current Switching by Silicon Diode
Using Tunneling-Assisted Impact Ionization Front S. N. Rukin, S. K. Lyubutin, B. G. Slovikovsky, S. N. Tsyranov Ural Division, Institute of Electrophysics Russian Academy of Sciences, Ekaterinburg, Russian Federation
Tuesday June 30 15:00 - 17:00 Colonial Session Chair: Tim Andreadis
Naval Research Laboratory Session O12: Explosive Pulsed Power 2
O12-1 Stand-Alone, FCG-Driven High Power Microwave System A. Young1, M. Elsayed1, J. Walter1, A. Neuber1, J. Dickens1, M. Kristiansen1, L. L. Altgilbers2 1Center for Pulsed Power and Power Electronics, Texas Tech University, Lubbock, TX, United States 2SMDC, U.S. Army, Huntsville, AL, United States
O12-2 Integration of a Self-Contained Compact Seed Source and Trigger Set for Flux Compression Generators M. A. Elsayed1, A. Neuber1, M. Kristiansen1, L. L. Altgilbers2
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1The Center for Pulsed Power and Power Electronics, Texas Tech University, Lubbock, Texas, United States 2SMDC, U.S. Army, Huntsville, Alabama, United States
O12-3 A New 40 MA Ranchero Explosive Pulsed Power System
J. H. Goforth, W. L. Atchison, S. A. Colgate, J. R. Griego, J. A. Guzik, D. H. Herrera, D. B. Holtkamp, G. Idzorek, A. Kaul, R. C. Kirkpatrick, R. T. Menikoff, H. Oona, P. T. Reardon, R. E. Reinovsky, C. L. Rousculp, A. G. Sgro, L. J. Tabaka, T. E. Tierney, D. T. Torres, R. G. Watt Los Alamos National Laboratory, Los Alamos, NM, United States
O12-4 Dominant Role of the Explosively Expanding Armature on the Initiation of Electric Discharge in Magnetic Flux Compression Generators S. I. Shkuratov1, J. Baird1, E. F. Talantsev2, L. L. Altgilbers3, A. H. Stults4 1Loki Incorporated, Rolla, MO, United States 2Pulsed Power LLC, Lubbock, TX, United States 3U.S. Army Space and Missile Defense Command, Huntsville, AL, United States 4U.S. Army Aviation Research, Development and Engineering Center, Huntsville, AL, United States
O12-5 Experimental Results using Ferromagnetic Generators to Load
Inductive Coils A. H. Stults Aviation and Missile Research, Development, and Engineering Center RDMR-WDF-S
O12-6 Conductivity of Explosively Shocked Polycrystalline and Single Crystal Potassium Chloride S. I. Shkuratov1, J. Baird1, E. F. Talantsev2, L. L. Altgilbers3, A. H. Stults4 1Loki Incorporated, Rolla, MO, United States 2Pulsed Power LLC, Lubbock, TX, United States 3U.S. Army Space and Missile Defense Command, Huntsville, AL, United States 4Development and Engineering Center, Huntsville, AL, United States
O12-7 Effect of Shock Wave Profile on the Magnetic Flux and Energy
Transfer in Miniature Ferromagnetic Primary Sources S. I. Shkuratov1, J. Baird1, E. F. Talantsev2, L. L. Altgilbers3, A. H. Stults4
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1Loki Incorporated, Rolla, MO, United States 2Pulsed Power LLC, Lubbock, TX, United States 3U.S. Army Space and Missile Defense Command, Huntsville, AL, United States 4U.S. Army Aviation Research, Development and Engineering Center, Huntsville, AL, United States
O12-8 Operation of Longitudinal Shock Wave Ferroelectric Generators in the Resistance Mode S. I. Shkuratov1, J. Baird1, E. F. Talantsev2, L. Altgilbers3 1Loki Incorporated, Rolla, MO, United States 2Pulsed Power LLC, Lubbock, TX, United States 3U.S. Army Space and Missile Defense Command, Huntsville, AL, United States
Wednesday July 1 9:15 - 11:15 Ballroom Session Chair: Susan L. Heidger
Air Force Research Laboratory (AFRL/RDHP) Session O13: Advanced Dielectrics O13-1 High Temperature Polymer Dielectrics from the Ring Opening
Metathesis Polymerization (ROMP) S. M. Dirk1, P. S. Sawyer1, J. S. Wheeler2, M. E. Stavig1, B. A. Tuttle2 1Organic Materials Department, Sandia National Laboratories, Albuquerque, NM, United States 2Electronic and Nanostructured Materials Department, Sandia National Laboratories, Albuquerque, NM, United States
O13-2 Dielectric Characterization of Polymer-Ceramic Nanocomposites* K. A. O'Connor, J. Smith, R. D. Curry Center for Physical and Power Electronics, University of Missouri-Columbia, Columbia, MO, United States
O13-3 Nonlinear Modeling of Ferroelectric Dielectrics Transmission
Line S. L. Henriquez1, M. S. Litz1, S. B. Bayne2, D. Katsis3 1Directed Energy and Power Generation, U.S. Army Research Laboratory, Adelphi, MD, United States
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2Texas Tech University, Lubbock, MD, United States 3Athena Energy Corp., Bowie, MD, United States
O13-4 Defect Modified PVDF Dielectric Polymers with Very High
Energy Density for Capacitor Application X. Zhou1, S. Zhang2, C. Zou3, Q. Zhang1,3 1Electrical Engineering, The Pennsylvania State University, University Park, PA, United States 2Strategic Polymer Science, Inc, State College, PA, United States 3Materials Research Institute, The Pennsylvania State University, University Park, PA, United States
O13-5 Computation of Dielectric Response of Polymers with Nonlinear Fillers K. Zhou, S. A. Boggs Institute of Material Science, University of Connecticut, Storrs, CT, United States
O13-6 High Electric Field Properties of Bi-Based Perovskite Solid Solutions D. P. Cann, B. J. Gibbons, M. R. Emerson, N. Triamnak Materials Science, School of Mechanical, Industrial, and Manufacturing Engineering, Oregon State University, Corvallis, United States
O13-7 Potential High Temperature, High Energy Density Dielectrics
for Multilayer Ceramic Capacitors for Power Applications C. A. Randall1, H. Ogihara1, S. S. N. Bharadwaja1, M. T. Lanagan1, S. Trolier-McKinstry1, C. Stringer2 1Materials Research Institute, The Pennsylvania State University, University Park, PA, United States 2Engineering Dept., The Pennsylvania State University-DuBois, DuBois, PA, United States
O13-8 Pulse Laser Deposition of Nd-Doped BaTiO3 Films for High
Energy Density Pulsed Power Capacitors P. S. Lee1, J. B. Lam1, M. -F. Lin1, J. Ma2 1School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore 2Temasek Laboratories, Nanyang Technological University, Singapore, Singapore
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Wednesday July 1 9:15 - 11:15 Colonial Session Chair: David Wetz
Institute for Advanced Technology, The University of Texas at Austin
Session O14: Pulsed Power Systems O14-1 An Update on NIF Pulsed Power
P. A. Arnold1, G. F. James1, D. E. Petersen1, D. L. Pendleton1, G. B. McHale1, F. Barbosa1, A. S. Runtal2, P. L. Stratton1 1Lawrence Livermore National Laboratory, Livermore CA, United States 2IAP World Services, Livermore CA, United States
O14-2 Optimizing Compact Marx Generator Networks
C. J. Buchenauer Electrical and Computer Engineering Department, University of New Mexico, Albuquerque, NM, USA
O14-3 A Control Theory Approach on the Design of a Marx Generator
Network L. Zaccarian1, S. Galleani1, C. J. Buchenauer2, C. T. Abdallah2, E. Schamiloglu2 1DISP, University of Roma, Tor Vergata, Roma, Italy 2Electrical and Computer Engineering Department, University of New Mexico, Albuquerque, NM, USA
O14-4 PHELIX
C. L. Rousculp, P. J. Turchi, W. A. Reass, D. M. Oro, F. E. Merrill, J. R. Griego, R. E. Reinovsky Los Alamos National Laboratory, Los Alamos, NM, United States
O14-5 Evaluation of Conductor Stresses in a Pulsed High-Current
Toroidal Transformer P. J. Turchi, C. L. Rousculp, W. A. Reass, D. M. Oro, J. R. Griego, R. E. Reinovsky Los Alamos National Laboratory, Los Alamos, NM, United States
O14-6 NDCX-II Pulsed Power System and Induction Cells
W. L. Waldron, L. L. Reginato, M. A. Leitner Lawrence Berkeley National Laboratory, Berkeley, CA, United States
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O14-7 State-of-the-Art of a Transmission-Line-Transfer Based
Multiple-Switch Pulsed Power Technology Z. Liu1, A. J. M. Pemen1, E. J. M. V. Heesch1, G. J. J. Winands2, K. Yan3 1Eindhoven University of Technology, Eindhoven, Netherlands 2TNO Science and Industry, Eindhoven, Netherlands 3Zhejiang University, Hangzhou, China
O14-8 Transients in the Capacitor Cells Circuits and Semiconductor
Switches Workability R. S. Enikeev, B. E. Fridman STC, D.V. Efremov Scientific Research Institute of Electrophysical Apparatus, St.-Petersburg, Russian Federation
Wednesday July 1 9:15 - 11:15 Chinese Room Session Chair: Timothy J. Renk
Sandia National Laboratories Session O15: Repetitive Pulsed Power and High Current
Pulsers O15-1 A 2MV, <300ps Risetime, 100Hz, Pulser for Generation of
Microwaves D. Morton1, J. Banister1, J. S. Levine1, T. Naff1, I. Smith1, H. Sze1, T. Warren1, D. Giri2, C. Mora3, J. Pavlinko3, J. Schleher3, C. E. Baum4 1L3 Pulse Sciences, San Leandro, CA, United States 2Pro-Tech, CA, United States 3SAIC, ABQ, NM, United States 4University of New Mexico, NM, United States
O15-2 Compact Solid State Modulator & RF System
S. M. Iskander Power Tubes & Systems, E2V Technology, Chelmsford, United Kingdom
O15-3 High Repetition Rate Pulsed Power Generator Using IGBTs
and Magnetic Pulse Compression Circuit T. Sakugawa1, K. Kouno1, K. Kawamoto1, H. Akiyama1, K. Suematsu2, A. Kouda2, M. Watanabe2
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1Graduate School of Science and Technology, Kumamoto University, Kumamoto, Japan 2Suematsu Electronics Co. Ltd., Yatsushiro, Japan
O15-4 Repetitive Solid State Pulse Modulator Based on a DC Voltage
Multiplier L. M. S. Redondo1, 2 1Instituto Superior de Engenharia de Lisboa, Lisbon, Portugal 2Centro de Fsica Nuclear da Universidade de Lisboa, Lisbon, Portugal
O15-5 Design and Operation of a 700 kV Arbitrary Waveform
Generator R. J. Adler, V. M. Weeks Applied Energetics, Tucson, AZ, United States
O15-6 Development on Repetitive Pulsed-Power Switching W. Jiang1, X. Wang1, K. Liu2, J. Qiu2, H. Li3 1Tsinghua University, Beijing, China 2Fudan University, Shanghai, China 3China Academy of Engineering Physics, Mianyang, China
O15-7 High Power FID Pulsers with Amplitude of up to 500 kV and Energy in Pulse of 1 kJ V. M. Efanov, M. V. Efanov, A. A. Dyublov, N. K. Savastianov FID GmbH, Burbach, Germany
O15-8 Mathematical Models of Conductive Media Explosion at Extremely High Linear Current Density S. I. Krivosheev, G. A. Shneerson, Y. E. Adamian High Voltage Techique, Sankt-Petersburg State Politechnical University, Saint Petersburg, Russian Federation
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Poster Session Wednesday July 1 11:15 - 12:30 East/State Session Chairs: Peter Duselis
Ktech Corporation Matthew T. Domonkos AFRL / RDHP
Mike M. Ong Lawrence Livermore National Laboratory
Session 01P: Microwave and RF Sources, Charged Particle
Beams and Sources, Dielectrics and Energy Storage
01P-1 Aging Characteristic of Insulation Materials under Laser
Irradiation and Pulsed Discharge J. Wang1, R. Z. Pan1, 2, P. Yan1 1Institute of Electrical Engineering, Chinese Academy of Sciences, BeiJing, China 2Graduate University, Chinese Academy of Sciences, BeiJing, China
01P-2 High-Voltage Pulsed Breakdown Testing of Organic Composite Dielectrics M. Roybal1, J. Buchenauer1, E. Schamiloglu1, J. Rossi2, S. Sawhill3, E. Savrun3 1University of New Mexico, Albuquerque, NM, United States 2National Institute for Space Research, São José dos Campos, Brazil, United States 3Sienna Technologies Inc., Woodinville, WA, United States
01P-3 Research Progress of Multilayer High Gradient Insulator
Technology C. Y. Ren, W. Q. Yuan, D. D. Zhang, J. Wang, P. Yan Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing, China
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01P-4 Methods to Increase Hold off Voltage of Polystyrene Dielectric J. L. Zirnheld, K. M. Burke, S. Olabisi, J. D. Campbell Energy Systems Institute, University at Buffalo, Buffalo, NY, United States
01P-5 Breakdown Strength of Al2O3 Doped Polymer Layers
S. S. M. Chung1,2, C. H. Cheng3, J. Y. Jian3, J. W. Lan1, H. Y. Lin4, S. H. Cheng5, T. W. Suen6 1of Elecronics Engineering, Southern Taiwan University of Technology, Tainan, Taiwan 2Center for Micro/Nana Science and Technology, National Cheng Kung University, Tainan, Taiwan 3Department of Chemical Engineering, Southern Taiwan University, Tainan, Taiwan 4Mechanical and System Research Laboratory, Industrial Technology Research Institute, Hsinchu, Taiwan 5Institute of Nuclear Energy Research, Atomic Energy Commission, Taoyuan, Taiwan 6Electronic Research Division, Chung-Shan Institute of Science and Technology, Taoyuan, Taiwan
01P-6 High Voltage Insulator Failures and Improvements Made in the
Oil and Water Section of the Z Machine at Sandia National Laboratories in 2008 B. S. Stoltzfus 1671, Sandia National Labs, Albuquerque, NM, United States
01P-7 A New Model of a Lightning Channel Corona Sheath During Discharge J. M. Cvetic1, B. I. Jeftenic2, P. V. Osmokrovic1, S. D. Marjanovic3 1Dept. of Microelectronics, Faculty of Electrical Engineering, Belgrade, Serbia 2Dept. of Electrical Drive, Faculty of Electrical Engineering, Belgrade, Serbia 3Dept. of Gaseous Electronics, Institute of Physics, Belgrade, Serbia
01P-8 Pulsed Breakdown Voltage Characteristics of Pressurized Carbon Dioxide up to Supercritical Conditions T. Kiyan1, K. Miyaji1, M. Takade1, H. Fukuhara2, M. Hara1, H. Akiyama1 1Graduate School of Science and Technology, Kumamoto University, Kumamoto, Japan
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2Department of Electrical and Computer Engineering, Kumamoto University, Kumamoto, Japan
01P-9 An Evaluation of Dielectric Materials for Use in Pulsed Power Devices P. J. Leask, R. A. Ibbotson, S. J. Evans Advanced Technology Centre, BAE Systems, Bristol, United Kingdom
01P-10 Phenomena Accompanying the Pulsed Electric Discharges in Water P. G. Rutberg, V. A. Kolikov, M. E. Pinchuk, A. Y. Stogov, V. N. Snetov Institute for Electrophysics and Electric Power Russian Academy of Science, St. Petersburg, Russian Federation
01P-11 Progress on Simulating the Initiation of Vacuum Insulator Flashover M. P. Perkins, T. L. Houck, J. B. Javedani, G. E. Vogtlin, D. A. Goerz National Security Engineering Division, Lawrence Livermore National Laboratory, Livermore, Ca, United States
01P-12 Cavity Initiation through an Evaporating Mechanism for the Pulse Breakdown in Liquids V. M. Atrazhev1, V. S. Vorob'ev1, I. V. Timoshkin2, S. J. MacGregor2, M. J. Given2 1Theoretical Department, Institute for High Temperatures, Moscow, Russian Federation 2Department EEE, University of Strathclyde, Glasgow, United Kingdom
01P-13 Pre-Breakdown Currents in Insulating Liquids Stressed with Non-Uniform DC Electric Field I. V. Timoshkin, M. J. Given, S. J. MacGregor, M. P. Wilson Department of EEE, University of Strathclyde, Glasgow, United Kingdom
01P-14 Impulse Breakdown Characteristics of Dielectric Materials Immersed in Insulating Oil M. P. Wilson1, S. J. MacGregor1, I. V. Timoshkin1, M. J. Given1, M. A. Sinclair2, K. J. Thomas2, J. M. Lehr3 1Dept. Electronic & Electrical Engineering, University of Strathclyde, Glasgow, United Kingdom
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2Pulsed Power Group, AWE Aldermaston, Reading, United Kingdom 3Exploratory Pulsed Power Technologies Branch, Sandia National Laboratories, Albuquerque, NM, United States
01P-15 A New Method for Electrical Tree Propagation in Solid Dielectrics M. Talaat1, A. El-Zein2, M. El Bahy3 1Electrical Power and Machines, Ph. D. Student, Zagazig, Egypt 2Electrical Power and Machines, Professor, Zagazig, Egypt 3Electrical, Professor, Sinai, Egypt
01P-16 Runaway Electrons Preionized Diffuse Discharges at High Pressure V. F. Tarasenko, E. H. Baksht, A. G. Burachenko, I. D. Kostyrya, M. I. Lomaev, D. V. Rybka High Current Electronics Institute, Tomsk, Russian Federation
01P-17 DC Electrical Breakdown of Water in a Sub-Micron Planar Gap C. Song, P. Wang ECE, Clemson University, Clemson, SC, United States
01P-18 Evaluation of Magnetic Insulation in SF6 Filled Regions T. L. Houck, T. J. Ferriera, D. A. Goerz, J. B. Javedani, R. D. Speer, L. K. Tully, G. E. Vogtlin Lawrence Livermore National Laboratory, Livermore, CA, United States
01P-19 Registration of Initial Stage of Air Breakdown in the Fields of Subgigawatt Ka-Band Microwave Pulses M. I. Yalandin1, A. G. Reutova1, K. A. Sharypov1, V. G. Shpak1, S. A. Shunailov1, M. R. Ulmasculov1, G. A. Mesyats2 1Institute of Electrophysics, Ural Branch of Russian Academy of Sciences, Ekaterinburg, Russian Federation 2Lebedev Physical Institute RAS, Moscow, Russian Federation
01P-20 The Influence of a DC Electric Field on High Power Microwave Window Flashover in Air and N2 Environments* J. Foster, M. Thomas, H. Krompholz, A. Neuber
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Center for Pulsed Power and Power Electronics, Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, TX, United States
01P-21 Helical Antennas for High Powered RF J. R. Mayes, M. G. Mayes, W. C. Nunnally, C. W. Hatfield Applied Physical Electronics, L.C., Austin, TX, United States
01P-22 A Marx Generator Driven Impulse Radiating Antenna T. A. Holt Applied Physical Electronics, L. C., Austin, TX, United States
01P-23 Ultrawideband Antennas for Imaging in the near Field S. Xiao1, M. Migliaccio1, J. T. Camp1, C. E. Baum2, K. H. Schoenbach1 1Old Dominion University, Frank Reidy Research Center for Bioelectrics, Norfolk, VA, United States 2University of New Mexico, Department of Electrical and Computer Engineering, Albuquerque, NM, United States
01P-24 Numerical Simulations of an Inverted Magnetron T. P. Fleming Directed Energy Directorate, Air Force Research Lab, Albuquerque, NM, United States
01P-25 A Versatile and Mobile L-Band High Power Microwave Systems M. U. Karlsson, M. E. Jansson, F. Olsson, D. D. Åberg Applied Physics, BAE Systems Bofors AB, KARLSKOGA, Sweden
01P-26 Analytical Calculation of Anode Current in Relativistic Magnetron A. D. Andreev1, M. I. Fuks2, K. J. Hendricks1, E. Schamiloglu2 1Directed Energy Directorate, Air Force Research Laboratory, Kirtland AFB, NM, United States 2ECE, University of New Mexico, Albuquerque, NM, United States
01P-27 Electric Field Distributions in the Cross-Sections of the SIC Hollow-Core Waveguides S. Asmontas1, L. Nickelson1, T. Gric1, R. Martavicius2 1Terhertz's Electronic Laboratory, Semiconductor Physics Institute, Vilnius, Lithuania
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2Electronic System Department, Gediminas Technical University, Vilnius, Lithuania
01P-28 PIC-Simulation of Highly-Effective, Non-Stationary Relativistic 70-GHz BWO M. I. Yalandin1, V. G. Shpak1, V. P. Tarakanov2, S. V. Zhakov3 1Institute of Electrophysics, Ural Branch of Russian Academy of Sciences, Ekaterinburg, Russian Federation 2High Energy Research Centre of Russian Academy of Sciences, Moscow, Russian Federation 3Institute of Metal Physics, Ural Branch of Russian Academy of Sciences, Ekaterinburg, Russian Federation
01P-29 Peculiarities of Transient Processes in Relativistic Backward-Wave Oscillators and Amplifiers A. Konyushkov, E. Abubakirov, A. Sergeev Russian Academy of Sciences, Institute of Applied Physics, Nizhny Novgorod, Russian Federation
01P-30 Effects of Coupling Conduct in Phase Matching of Parallel Virtual Cathode Oscillators S. S. M. Chung1, 2, T. I. Tzeng3, H. Y. Lin4, S. H. Cheng5, T. W. Suen6 1Department of Electronics Engineering, Southern Taiwan University of Technology, Tainan, Taiwan 2Center for Micro/Nana Science and Technology, National Cheng Kung University, Tainan, Taiwan 3Computational Application Division, National Center of High-performance Computing, Hsinchu, Taiwan 4Mechanical and System Research Laboratory, Industrial Technology Research Institute, Hsinchu, Taiwan 5Institute of Nuclear Energy Research, Atomic Energy Commission, Taoyuan, Taiwan 6Electronic Research Division, Chung-Shan Institute of Science and Technology, Tauyuan, Taiwan
01P-31 Optimization of the Energy Efficiency for a Coaxial Vircator M. U. Karlsson, F. Olsson, D. Ã…berg, M. E. Jansson Applied Physics, BAE Systems Bofors AB, KARLSKOGA, Sweden
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01P-32 High Power S-Band Microwave Radiation from Small Body Waveguides E. C. Becker, S. D. Kovaleski, J. M. Gahl University of Missouri-Columbia, Columbia, MO, United States
01P-33 Large Signal Analysis of Ring-Bar Slow-Wave Structures for Ku-Band Traveling-Wave Tubes D. T. Lopes1, C. C. Motta2 1Nuclear & Energetic Research Institute, Sao Paulo, Brazil 2University of Sao Paulo, Sao Paulo, Brazil
01P-34 RF Generation in a Discrete Element Nonlinear Transmission Line D. M. French1, R. M. Gilgenbach1, Y. Y. Lau1, J. W. Luginsland2, D. Shiffler3 1Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI, United States 2NumerEx, Albuquerque, NM, United States 3Directed Energy Directorate, Air Force Research Laboratory, Albuquerque, NM, United States
01P-35 Numerical Simulations of the Influence of a Reflector in a Coaxial Vircator C. Möller, T. Hurtig, A. Larsson, S. E. Nyholm Defence & Security, Systems and Technology, Swedish Defence Research Agency (FOI), Stockholm, Sweden
01P-36 UNIPIC: a Novel Particle-in-Cell Simulation Method for Design of High Power Terahertz Vacuum Electron Devices H. Zhang, J. Wang School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an, China
01P-37 Relativistic Resonant TWT with Bragg Reflectors V. A. Gintsburg1, N. G. Kolganov1, N. F. Kovalev1, M. I. Fuks2, E. Schamiloglu2 1Branch of High-Current Microwave Electronics, Institute of Applied Physics, Nizhny Novgorod, Russia 2Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, NM, USA
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01P-38 Experimental Investigation of the Relativistic Cherenkov Microwave Oscillator without a Guiding Magnetic Field E. M. Totmeninov, A. I. Klimov, V. V. Rostov Siberian Branch RAS, Institute of High Current Electronics, Tomsk, Russian Federation
01P-39 Pulse Power Technology Challenge of High-Current Secondary Emission Magnetron Injection Gun S. Cherenshchykov National Science Center, Kharkov, Ukraine
01P-40 MAGIC3D Electromagnetic FDTD-PIC Code Dense Plasma Model Benchmark A. J. Woods, L. D. Ludeking Mission Systems, Alliant Techsystems (ATK), Newington, VA, United States
01P-41 Modeling of a Gridded Electron Gun for Traveling-Wave Tubes C. C. Xavier1, C. C. Motta2 1Instituto de Pesquisas Energticas e Nucleares/CNEN-SP, Sao Paulo, Brazil 2University of Sao Paulo - USP, Sao Paulo, Brazil
01P-42 ELECTRON Family Generators of Atmospheric Plasma with Runaway Electrons A. N. Maltsev1, I. R. Arslanov2, A. Y. Ivanov2, D. Y. Kolokolov2, I. N. Lapin2, S. N. Garagaty2, V. V. Chupin2 1Institute of Atmospheric Optics Russian Academy of Sciences, Tomsk, Russian Federation 2Electrodinamic Systems & Technologies, LLC, Tomsk, Russian Federation
01P-43 Twin Electron Beam Diode Design A. W. P. Jones Hydrodynamics, Atomic Weapons Establishment, Reading, United Kingdom
01P-44 Misalignment Effects on Beam Dynamics in AIRIX S. J. Pichon, M. Caron, L. Hourdin CEA DAM Ile-de-France, Arpajon, France
01P-45 Explosive Velvet Cathode Emission on a 4 MV, 2 kA, 60 ns Pulsed Power Diode M. Toury, M. Caron, R. Rosol, B. Etchessahar CEA Polygone d'Expérimentation de Moronvilliers, Pontfaverger-Moronvilliers, France
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01P-46 Determination of Emission Behaviour of Carbon Fibre Cathodes W. An, G. Mueller, A. Weisenburger Institut für Hochleistungsimpuls- und Mikrowellentechnik, Forschungszentrum Karlsruhe Institute fro Pulsed Power and Microwave Technique, Eggenstein-Leopoldshafen, Germany
01P-47 Multicapillary and Carbon Fiber Cathodes for High-Current Electron Beam Generation J. Z. Gleizer, V. Vekselman, Y. Hadas, V. T. Gurovich, Y. E. Krasik Physics, Technion Israel Institute of Technology, Haifa, Israel
01P-48 Negative-Polarity Rod-Pinch Diode Experiments on RITS-6 J. J. Leckbee1, B. V. Oliver1, M. D. Johnston1, K. D. Hahn1, S. Portillo1, B. Bui2 1Sandia National Laboratories, Albuquerque, NM, United States 2Ktech Corporation, Albuquerque, NM, United States
01P-49 Radiographic Diode Optimization in the Presence of Sheath Current in a MITL on RITS-6 K. Hahn1, B. V. Oliver1, D. V. Rose2, N. Bruner2, D. R. Welch2, V. Bailey3, J. Leckbee1, E. Schamiloglu4 1Sandia National Labs, Albuquerque, NM, United States 2Voss Scientific, Albuquerque, NM, United States 3L-3 Communications, San Leandro, CA, United States 4University of New Mexico, Dept. of Electrical and Computer Engineering, Albuquerque, NM, United States
01P-50 Measurements of Energy Spectra and Spatial Profile of Large-Area Diode RITS-6 Electron Beam T. J. Webb1, B. V. Oliver1, D. R. Welch2, J. Zier3, Y. Y. Lau3, R. Gilgenbach3 1Sandia National Laboratories, Albuquerque, NM, United States 2Voss Scientific, Albuquerque, NM, United States 3University of Michigan, Ann Arbor, Michigan, United States
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01P-51 Development of a Large Area, High Current, Repetitively Pulsed Diode for KrF Lasers* M. C. Myers1, J. D. Sethian1, F. Hegeler2, M. Friedman2, M. F. Wolford1, P. M. Burns3, R. L. Jaynes4, J. L. Giuliani1 1Plasma Physics Division, Naval Research Laboratory, Washington, DC, United States 2Commonweatlth Technologies, Inc., Alexandria, VA, United States 3Research Support Instruments, Lanham, MD, United States 4Science Applications International Corp., McLean, VA, United States
01P-52 Modeling Multipactor in RF Devices P. H. Stoltz, C. Nieter, C. Roark Tech-X Corporation, Boulder, CO, United States
01P-53 Terahertz Radiation Generation via Optical Rectification of X-Mode Laser in a Rippled Density Magnetized Plasma V. K. Tripathi, L. Bhasin Physics Department, Indian Institute of Technology Delhi, New Delhi, India
01P-54 Electron Beam Source Based on the Plasma Sheets Having Micron-Scale Width D. V. Yarmolich, V. V. Vekselman, V. T. Gurovich, J. Felsteiner, J. Z. Gleizer, Y. E. Krasik Physics, Technion, Haifa, Israel
Wednesday, July 1 13:30 - 14:45 East/State Session Chairs: Kim Morales Naval Surface Warfare Center- Dahlgren
Keith LeChien Sandia National Laboratories Session 02P: High Energy Density Plasmas and Pulsed
Power Switches and Components
02P-1 Prefire Probability of the Switch Type Fast LTD A. A. Kim, S. V. Frolov, V. M. Alexeenko, V. A. Sinebryukhov
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Institute of High Current Electronics, Tomsk, Russian Federation
02P-2 Synchronous Triggering of Multiple, Electrically-Isolated Vacuum Switches Using a Coaxial Transformer V. Gorodetsky High Power Solution Division, Science Applications International, Manassas, VA, United States
02P-3 Experiment and Circuit Model of Laser-Triggered Flashover Switch R. Z. Pan 1 , 2, J. Wang1, W. M. Ouyang1,2, G. S. Sun1, P. Yan1 1Institute of Electrical Engineering, Chinese Academy of Sciences, BeiJing, China 2Graduate University, Chinese Academy of Sciences, BeiJing, China
02P-4 Experiment of Laser-Triggered Flashover in Pulsed Voltage R. Z. Pan1, 2, J. Wang1, W. M. Ouyang1,2, G. S. Sun1, P. Yan1 1Institute of Electrical Engineering, Chinese Academy of Sciences, BeiJing, China 2Graduate University, Chinese Academy of Sciences, BeiJing, China
02P-5 Radial Design of Closing Multigap Switch V. Kladukhin, S. Khramtsov, S. Kladukhin, V. Yalov, P. Zagulov Institute of Electrophysics of Russian Academy of Sciences, Ekaterinburg, Russian Federation
02P-6 Breakdown Strength Criteria of a Spark Gap Switch in High Pressure SF6 Gas for Pulsed Power S. H. Nam1, H. Rahaman1, H. Heo1, S. S. Park1, J. W. Shin2, J. H. So2, W. Jang2 1Pohang Accelerator Laboratory, Pohang, South Korea 2ADD, Daejeon, South Korea
02P-7 Study of Arc Velocity in an Arc-Rotating Gap Based on B-dot Probes R. Guo, J. He, C. Zhao, L. Chen, Y. Pan Dept. High Voltage Engineering, College of Electric and Electronic Engineering, Hust, Wuhan, China
02P-8 Multigap Pseudospark Switch for FAIR K. Frank1, I. J. Petzenhauser2, B. -J. Lee3, U. Blell2
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1Center for Pulsed Power and Power Electronics, Texas Tech University, Lubbock, TX, United States 2FAIR Synchrotrons, GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt, Germany 3Institute of Applied Physics, Goethe University, Frankfurt, Germany
02P-9 Measurement of the Effective Length of Laser-Plasma Channels in a Laser Triggered Gas Switch by Guided Microwave Backscattering M. Gilmore1, B. S. Stoltzfus2, M. E. Savage2, A. G. Lynn1 1University of New Mexico, Albuquerque, NM, United States 2Sandia National Laboratories, Albuquerque, NM, United States
02P-10 Development of High-Power Photoconductive Semiconductor Switches W. Xie1, H. Li1, H. Liu1, J. Liu1, J. Yuan2, X. Wang2, W. Jiang2 1Institute of Fluid Physics, CAEP, Sichuan, China 2Department of Electrical Engineering, Tsinghua University, Beijing, China
02P-11 Performance Improvements of the 6.1-MV Laser-Triggered Gas-Switch on the Refurbished Z K. R. LeChien1, W. A. Stygar1, M. E. Savage1, D. E. Bliss1, P. E. Wakeland2 1Sandia National Laboratories, Albuquerque, NM, USA 2Ktech Corp., Albuquerque, NM, USA
02P-12 Investigation of UV LEDs for Compact Back-Lighted Thyratron Triggering C. Jiang, E. Sozer, H. Chen, W. Johnson, M. A. Gundersen EE-Electrophysics, University of Southern California, Los Angeles, CA, United States
02P-13 High Action Switching with the Extreme Break over Diode (XBOD®) A. Griffin, D. Giorgi, G. Celestin, T. Navapanich OptiSwitch Technology Corporation, San Diego, CA, United States
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02P-14 Pulse Triggered Spark Gap Design Aided by Charge Simulation Method with Consideration of Space Charge Effects L. S. N. Wang Electromagnetic Survivability Division, Survivability & Vulnerability Assessment Division/WSMR, White Sands Missile Range, United States
02P-15 Arc Dynamics in High Current Rail Spark Gaps A. V. Kharlov Pulsed Power, Institute of High Current Electronics, Tomsk, Russian Federation
02P-16 Formation of Multi Channels in Multi Gap Gas Switch for Linear Transformer Driver D. X. Liu Electrical Engineering/High Voltage, Xi'an Jiaotong University, School of Electrical Engineering, High Voltage Division, Xi'an, China
02P-17 Development of a Sub-Nanosecond Jitter Eight-Output 150kV Trigger Generator L. Peng1, Q. Aici1, S. Fengju2, Y. Jiahui2 1Electrical Engineering, Xi'an Jiaotong University, Xi'an, China 2Pulsed Power, NorthWest Institute of Nuclear Technology, Xi'an, China
02P-18 Design and Performance Analysis of Two-Stage Mpc System D. D. Zhang1, P. Yan1, J. Wang1, Y. Zhou1, 2, 3 1Institute of Electrical Engineering, Chinese Academy of Sciences, BeiJing, China 2Graduate School of Chinese Academy of Sciences, BeiJing, China 3School of Automation and Electrical Engineering, Tianjin University of Technology and Education, TianJin, China
02P-19 Magnetic Characteristics of Saturable Pulse Transformer in Magnetic Pulse Compression System D. D. Zhang1, P. Yan1, J. Wang1, Y. Zhou1,2,3 1Institute of Electrical Engineering, Chinese Academy of Sciences, BeiJing, China 2Graduate School of Chinese Academy of Sciences, BeiJing, China 3School of Automation and Electrical Engineering,
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Tianjin University of Technology and Education, TianJin, China
02P-20 Power and Jitter Optimization of a 1.5 kV, 100 ps Rise-Time, 50 kHz Repetition-Rate Pulsed Power Generator L. M. Merensky1, A. F. Kardo-Sysoev2, A. N. Flerov3, D. Shmilovitz4, A. S. Kesar1 1Propulsion Physics Laboratory, Soreq NRC, Yavne, Israel 2Ioffe PTI, St. Petersburg, Russia 3The Baltic State Technical University, St. Petersburg, Russia 4Faculty of Engineering, Tel Aviv University, Ramat Aviv, Israel
02P-21 Silicon Diode Evaluated as Rectifier for Wide-Pulse Switching Applications H. K. OBrien1, A. Ogunniyi1, W. Shaheen2, C. J. Scozzie1, V. Temple3 1US Army Research Laboratory, Adelphi, MD, United States 2Berkeley Research Associates, Beltsville, MD, United States 3Silicon Power Corporation, Clifton Park, NY, United States
02P-22 High Electric Field Packaging of Silicon Carbide Photoconductive Switches C. V. Hettler, C. R. James, J. C. Dickens Center for Pulsed Power and Power Electronics, Texas Tech University, Lubbock, TX, United States
02P-23 Balancing Circuit for a 5kV/100ns Pulsed Power Switch Based on SiC-JFET Super Cascode J. Biela, D. Aggeler, B. Dominik, J. W. Kolar D-ITET, Power Electronics Laboratory, ETH Zurich, Zurich, Switzerland
02P-24 Fast Optical Gating of 5kV Silicon Thyristors H. D. Sanders, S. C. Glidden Applied Pulsed Power, Inc., Freeville, NY, United States
02P-25 Prediction of the Characteristics of Transformer Oil under Different Operation Conditions W. A. Ahmed
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Electrical Power and Machines, Helwan University, Faculty of Engineering, Cairo, Egypt
02P-26 Investigation of Corona Discharge around 400 kV Conductors Due to Extra-Low Frequency Electromagnetic Fields S. Carsimamovic1, Z. Bajramovic1, P. Osmokrovic2, M. Veledar3, A. Carsimamovic3, E. Aganovic3, S. Nuic4 1Faculty of Electrical Engineering, University of Sarajevo, Sarajevo, Bosnia and Herzegovina 2Faculty of Electrical Engineering, University of Belgrade, Belgrade, Serbia 3Independent System Operator in B&H, Sarajevo, Bosnia and Herzegovina 4Dalekovod, Zagreb, Croatia
02P-27 Effect of Shielding on Reduction of the Eddy Current Losses in Power Transformer Tank Wall M. Motalleb, M. Vakilian, A. Abbaspour Electrical Engineering, Sharif University of technology, Tehran, Iran
02P-28 Experimental Study of Current Loss in a Post-Hole Convolute on a 1 Ma Linear Transformer Driver M. R. Gomez1, R. M. Gilgenbach1, D. M. French1, J. C. Zier1, Y. Y. Lau1, M. R. Lopez2, M. E. Cuneo2, M. G. Mazarakis2 1Plasma, Pulsed Power, and Microwave Lab - Nuclear Engineering and Radiological Sciences Department, University of Michigan, Ann Arbor, MI, United States 2Sandia National Laboratories, Albuquerque, NM, United States
02P-29 Inductive Storage - Inductor for Capacitor Cell N. A. Kovrizhnykh, A. A. Drozdov, R. S. Enikeev, B. E. Fridman, A. U. Konstantinov, U. L. Kryukov, A. A. Malkov STC, D.V. Efremov Scientific Research Institute of Electrophysical Apparatus, St.-Petersburg, Russian Federation
02P-30 Interferometric and Spectroscopic Measurements on a Triggered Plasma Opening Switch Source A. G. Lynn1, M. Gilmore1, N. R. Devarapalli1, M. E. Savage2, D. P. Jackson2, B. S. Stoltzfus2 1Electrical & Computer Engineering Dept., University of New Mexico, Albuquerque, NM, United States 2Sandia National Laboratories, Albuquerque, NM, United States
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02P-31 Transient Processes Features in the Electric Circuit with the Ferromagnetic Open Switch G. A. Shneerson, I. P. Efimov, A. V. Kononenko High Voltage Pulse Technique, Saint-Petersburg State Polytechnical University, Saint-Petersburg, Russian Federation
02P-32 Influence of Current-Breaking Switching Operations on Vacuum Insulation P. Osmokrovic1, M. Jurosevic1, G. Ilic2, R. Maric1 1Faculty of Electrical Engineering, University of Belgrade, Belgrade, Serbia 2Electric Power Industry of Serbia (EPS), Belgrade, Serbia
02P-33 Measurement of Arc Velocity in an Arc-Rotating Pulsed Power Switch Based on B-Dot Probes H. Junjia, G. Rui College of Electrical & Electronics Engineering, Huazhong Univ. of Sci. & Tech., Wuhan, China
02P-34 Erosion and Lifetime Evaluation of Molybdenum Electrode under High Energy Impulse Current T. K. Raychaudhuri, D. K. Pal, A. Upadhyay, R. Thakur Metallurgy Division, TBRL, Chandigarh, India
02P-35 Streamer in High Gain GaAs Photoconductive Semiconductor Switches H. Liu1, 2, C. Ruan1 1College of Physical Electronics, University of Electronic Science and Technology of China, Chengdu, SiChuan, China 2College of Electronic and Information Engineering, Chengdu University, Chengdu, SiChuan, China
02P-36 Comparison of Recovery Time and dV/dt Immunity for Si and SiC SGTOs A. Ogunniyi1, H. O'Brien1, C. Scozzie1, W. Shaheen2, A. Agarwal3, V. Temple4 1US Army Research Laboratory, Adelphi, MD, United States 2Berkeley Research Associates, Beltsville, MD, United States 3Cree Inc, Durham, NC, United States 4Silicon Power Corporation, Clifton Park, NY, United States
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02P-37 12.6 kA / 20 kV / 300 Hz Reverse Conducting Solid State Switch for DeNox / DeSox Modulator A. Welleman, S. Gekenidis ABB Switzerland Ltd, Semiconductors, Lenzburg, Switzerland
02P-38 Modular 30 kV IGBT Switch for Pulsed Power Applications V. Zorngiebel1, E. Spahn1, A. Welleman2, S. Scharnholz1 1French-German Research Institute of Saint-Louis, 68301 Saint Louis Cedex, France 2ABB Switzerland Ltd. Semiconductors, 5600 Lenzburg, Switzerland
02P-39 Performance Study of a Novel 13.5 kV Multichip Thyristor Switch S. Scharnholz1, V. Brommer1, V. Zorngiebel1, A. Welleman2, E. Spahn1 1ISL, Saint Louis, France 2ABB Switzerland Ltd, Semiconductors, Lenzburg, Switzerland
02P-40 The PFL "Squiggle:" An independent Monitor of Trigger and Cascade Section Runtimes D. E. Bliss1, J. R. Woodworth1, T. G. Avila2, H. J. Seamen2, M. E. Savage1 1Sandia National Laboratories, Albuquerque, NM, USA 2Ktech Corporation, Albuquerque, NM, USA
02P-41 Concept of a Two-Stage Liner Generator of Dense High-Temperature Plasma V. A. Vasyukov, A. V. Ivanovskiy, A. I. Kraev, A. A. Petrukhin, V. F. Rybachenko, A. A. Sadovoy, V. V. Zmushko, Y. A. Rezchikova Russian Federal Nuclear Center, Russia Research Institute of Experimental Physics, Sarov, Nizhniy Novgorod Region, Russia
02P-42 Pulsed Source of Energy on the Basis of a Helical Explosive Magnetic Generator with a Built-in Current Opening Switch of Cumulative Type P. V. Duday, V. A. Ivanov, A. I. Kraev, S. V. Pak, A. N. Skobelev, R. R. Zubaerova Russian Federal Nuclear Center, Russia Research Institute of Experimental Physics, Sarov, Nizhniy Novgorod Region, United States
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02P-43 A Simple Operation Model of a Plasma Opening Switch with Longitudinal Magnetic Field at the Erosion Stage A. V. Ivanovskiy Russian Federal Nuclear Center, Russia Research Institute of Experimental Physics, Sarov, Nizhniy Novgorod Region, Russia
02P-44 A Device to Study the Properties of Substances at the Impact of the Magnetically Driven Cylindrical Condensed Liner on the Targets at the Velocity > or = 20 Km/s A. M. Buyko, Y. N. Gorbachev, A. V. Ivanovsky, V. V. Pavliy, A. A. Petrukhin, N. I. Sitnikova, V. B. Yakubov Russian Federal Nuclear Center, Russia Research Institute of Experimental Physics, Sarov, Nizhniy Novgorod Region, Russia
02P-45 Considerations of a High Repitition Capillary Discharge Operated in Nitrogen as a Water-Window X-Ray Microscope Source E. S. Wyndham, M. Favre, M. P. Valdivia, J. C. Valenzuela Facultad de Fisica, Pontificia Universidad Catolica de Chile, Casilla, Santiago de Chile, Chile
02P-46 Electron Emission Characteristics of Cardon-Nano Tubes under Low Vacuum Conditions* S. Li, H. Kirkici Electrical and Computer Engineering, Auburn University, Auburn, AL,, United States
02P-47 Beam-Plasma Interaction under Weak Coupling in Finite External Magnetic Field E. V. Rostomyan Institute of Radiophysics & Electronics National Ac Sci of Armenia, Ashtarack, Armenia
02P-48 Magneto-Hydrodynamic Simulation of Z-Pinches Taking into Account Multigroup Diffusion Radiation Transfer V. D. Selemir, P. B. Repin, A. P. Orlov, B. G. Repin Scientific and Technical Center of Physics, Russian Federal Nuclear Center - VNIIEF, Sarov, Nizhny Novgorod Region, Russian Federation
02P-49 Liner Experiments with Explosive Power Sources V. D. Selemir, V. A. Demidov, P. B. Repin, A. P. Orlov, V. F. Ermolovich, A. S. Boriskin, G. M. Spirov, I. V. Pikulin, A. A. Volkov, O. M. Tatsenko, A. N. Moiseenko, I. M. Markevtsev,
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S. A. Kazakov, E. V. Shapovalov, B. P. Giterman, Y. V. Vlasov, M. A. Barinov, A. G. Repiev, E. G. Danchenko, A. P. Romanov, Y. N. Lashmanov, A. V. Filippov, E. A. Bychkova, E. S. Rudneva, V. S. Pokrovsky, D. S. Pokrovsky, A. R. Volodko Scientific and Technical Center of Physics, Russian Federal Nuclear Center - VNIIEF, Sarov, Nizhny Novgorod Region, Russian Federation
02P-50 Two-Dimensional Magneto-Hydrodynamic Simulation of Z-Pinches Considering Hall Effect P. B. Repin, V. D. Selemir, A. P. Orlov Scientific and Technical Center of Physics, Russian Federal Nuclear Center - VNIIEF, Sarov, Nizhny Novgorod Region, Russian Federation
02P-51 The Role of Electron Heat Conductivity and Radiation Transport in 1D Simulations of Wire Explosions in Zebra Experiments * S. F. Garanin, S. D. Kuznetsov All-Rusiian Research Institute of Experimental Physics (VNIIEF), Sarov, Russian Federation
02P-52 Electrical Recovery after a Vacuum Discharge for Highly Repetitive Plasma EUV Sources T. Yamamoto1, K. Nagano1, D. Yasui1, A. Kuwahata1, S. Katsuki2, T. Sakugawa1, H. Akiyama1 1Graduate School of Science and Technology, Kumamoto University, Kumamoto, Japan 2Bioelectrics Research Center, Kumamoto University, Kumamoto, Japan
02P-53 Gas-Filled-Capillary Discharge Experiment J. Schmidt, K. Kolacek, O. Frolov, V. Prukner, J. Straus Institute of Plasma Physics AS CR, v.v.i., Prague, Czech Republic
02P-54 Numerical Matching an EUV Laser of Recombination Type on Hydrogen-like Ions of Nitrogen with a Pulse Energy Supply System V. A. Burtsev, N. V. Kalinin Center of High Power Engineering, Efremov Scientific Research Institute of Electrophysical Apparatus, Saint Petersburg, Russian Federation
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02P-55 A Nanosecond Discharge-Based X-Ray Source in Atmospheric Pressure Air with a Subnanosecond Pulse Duration V. F. Tarasenko, I. D. Kostyrya High Current Electronics Institute, Tomsk, Russian Federation
02P-56 Theory and Experimental Measurements of Contact Resistance W. Tang, M. R. Gomez, Y. Y. Lau, R. M. Gilgenbach, J. Zier Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI, United States
02P-57 Effect of Self Generated Magnetic Field on Double Layer Proton Acceleration from Laser Irradiated Thin Metal Foils V. K. Tripathi1, A. Sharma1, C. S. Tripathi2 1Physics Department, Indian Institute of Technology Delhi, New Delhi, India 2Department of Physics, University of Maryland, College Park, Maryland, United States
02P-58 Use of RHEPP-1 Repetitive Ion Beam to Simulate Exposure of IFE Chamber Wall Materials to Repeated Reactor-Level Ion Fluences* ** T. J. Renk1, P. P. Provencio1, J. P. Blanchard2, S. Sharafat3 1Sandia National Laboratories, Albuquerque, NM, United States 2University of Wisconsin, Madison, WI, United States 3University of California, Los Angeles, CA, United States
02P-59 Optimal Design of a Grid Cathode Structure in Spherically Convergent Beam Fusion Device by Response Surface Methodology Combined with Experimental Design H. Ju, B. Kim, H. Hwang, K. Ko Electric Engineering, Hanyang University, Seoul, South Korea
02P-60 Analyses of the Gyroelectric Plasma Rod Waveguide S. Asmontas1, L. Nickelson1, T. Gric1, R. Martavicius2 1Terahertz's Electronics Laboratory, Semiconductor Physics Institute, Vilnius, Lithuania 2Electronic System Department, Gediminas Technical University, Vilnius, Lithuania
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Wednesday, July 1 15:00 - 17:00 Colonial Oral Sessions Session Chair: Dwayne Surls
Institute for Advanced Technology, University of Texas at Austin
Session O16: Electromagnetic Launchers and Pulsed Power
Systems O16-1 Research on a Plasma-Driven Railgun for Economical Access
to Low Earth Orbit D. A. Wetz, F. Stefani, I. R. McNab, J. V. Parker Institute for Advanced Technology, The University of Texas at Austin, Austin, TX, United States
O16-2 Development of a 40-Stage Distributed Energy Railgun R. W. Karhi1, M. Giesselmann1, D. Wetz2, J. Diehl1 1Center for Pulsed Power and Power Electronics, Texas Tech University, Lubbock, Texas, United States 2Institue for Advanced Technology, University of Texas, Austin, Texas, United States
O16-3 Modeling of the Contact Resistance and the Heating of the
Contact of a Multiple Brush Projectile for Railguns with the Finite Element Code ANSYS M. I. R. Coffo, J. Gallant Weapon Systems and Ballistics, Royal Military Academy, Brussels, Belgium
O16-4 Rail Current Reduction by Series Augmentation of an EM
Railgun M. J. Veracka1, C. N. Boyer2, J. M. Neri3, T. G. Engel4 1Tactical Electronic Warfare, Naval Research Laboratory, Washington, DC, United States 2Titan Group, L3 Communications, Reston, VA, United States 3Plasma Physics, Naval Research Laboratory, Washington, DC, United States 4ECE, University of Missouri, Columbia, MO, United States
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O16-5 Effect of Resistance Modification on EML Capacitor Bank Performance B. M. Huhman1, J. M. Neri1, T. Lockner2 1Plasma Physics Division, US Naval Research Laboratory, Washington, DC, United States 2Electrophysics Applications, LLC, Albuquerque, NM, United States
O16-6 Experimental Investigation of the Operation of an Electrodynamic Spraying Setup G. A. Shvetsov, Y. L. Bashkatov, A. G. Anisimov, V. V. Zykov, V. P. Chistyakov Lavrentyev Institute of Hydrodynamics, Novosibirsk, Russian Federation
O16-7 Genesis: A 4 MA Programmable Pulsed Power Driver for Isentropic Compression Experiments S. F. Glover1, K. W. Reed1, G. E. Pena1, L. X. Schneider1, J. -P. Davis1, C. A. Hall1, R. J. Hickman1, K. C. Hodge2, J. M. Lehr1, D. J. Lucero3, D. H. McDaniel1, J. G. Puissant2, J. M. Rudys1, M. E. Sceifford1, S. J. Tullar2, D. M. Van De Valde3, F. E. White2 1Sandia National Laboratories, Albuquerque, United States 2Ktech Corporation, Albuquerque, United States 3EG&G, Albuquerque, United States
O16-8 Analytic Model and Experimental Study of the UNM Reltron Pulsed Power System S. Soh, E. Schamiloglu, J. Gaudet, R. L. Terry Electrical & Computer Engineering, University of New Mexico, Albuquerque, New Mexico, United States
Wednesday, July 1 15:00 - 17:00 Ballroom Session Chair: Paul Armistead
Office of Naval Research Session O17: Pulsed Power Capacitors
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O17-1 High Energy Density Capacitors for Pulsed Power Applications F. W. MacDougall1, J. B. Ennis1, X. H. Yang1, R. Jow2, J. Ho2, S. Scozzie2, R. A. Cooper1, J. E. Golbert1, J. F. Bates1, C. Naruo1, M. Schneider1, N. Keller1, S. Joshi1 1General Atomics Electronic Systems, Inc., San Diego CA, United States 2US Army Research Laboratory, Adelphi MD, United States
O17-2 Achieving High Dielectric Constant Polymer/BaTiO3 Nanocomposites at Low Filling Ratios J. Wang1, L. Zhu1 , 2, Q. Wang3, J. Huang3, W. Li3 1Institute of Materials Science and Department of Chemical, Materials and Biomolecular Engineering, University of Connecticut, Storrs, CT, United States 2Department of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, OH, United States 3Agiltron, Inc., Woburn, MA, United States
O17-3 Sub-Microsecond, 50 kV-Class Pulsed Power Capacitor Design and Life Testing M. T. Domonkos1, S. Heidger1, D. Shiffler1, T. Tran1, D. Brown2, C. W. Gregg2, K. Slenes3 1AFRL/RDHP, Air Force Research Laboratory, Kirtland AFB, NM, United States 2SAIC, Albuquerque, NM, United States 3TPL, Inc., Albuquerque, NM, United States
O17-4 High Energy Density Film Capacitors S. Zhang1, Q. Zhang1, S. Rockey1, B. Zellers1, C. Zou2 1Strategic Polymer Sciences, Inc., State College, PA, United States 2MRI, Penn State University, University Park, PA, United States
O17-5 Advanced Multilayer Ceramic Capacitors with High Energy Density for Pulse Power Applications S. Kwon1, W. Hackenberger1, J. Day2 1TRS Technologies, State College, PA, United States 2Calramic Technologies LLC, Reno, NV, United States
O17-6 Monte Carlo Modeling of Heterogeneities in Ceramic, Polymer, and Composite Capacitors E. Furman, G. Sethi, B. Koch, M. Lanagan
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Materials Research Institute, Pennsylvania State University, University Park, PA, United States
O17-7 Analysis of Capacitor Performance by Repetitive Pulsed Charge Discharge Operation S. L. Heidger1, E. Loree2, M. Domonkos1, D. Shiffler1, W. Hackenberger3 1Air Force Research Laboratory (AFRL/RDHP), Kirtland AFB, NM, United States 2Loree Engineering, Albuquerque, NM, United States 3TRS Technologies, State College, PA, United States
O17-8 Application of a Quasi-Static EM Solver to Optimization of Low Inductance Film Capacitors S. Qin, S. A. Boggs Institute of Materials Science, University of Connecticut, Storrs, CT, United States
Wednesday July 1 15:00 - 17:00 Chinese Room Session Chair: Richard Ness Ness Engineering Session O18: Power Electronics and Systems O18-1 A High-Power High Voltage Power Supply for Long-Pulse
Applications A. Pokryvailo, C. Carp, C. Scapellati Spellman High Voltage Electronics Corporation, Hauppauge, NY, United States
O18-2 High Power, High Efficiency, Low Cost Capacitor Charger Concept and Demonstration A. Pokryvailo, C. Carp, C. Scapellati Spellman High Voltage Electronics Corporation, Hauppauge, NY 11788, United States
O18-3 ILC Marx Modulator Development Program Status C. Burkhart, T. Beukers, M. Kemp, R. Larsen, K. Macken, M. Nguyen, J. Olsen, T. Tang
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SLAC National Accelerator Laboratory, Menlo Park, CA, United States
O18-4 Design Considerations for a PEBB-based Marx-topology ILC Klystron Modulator K. Macken, T. Beukers, C. Burkhart, M. Kemp, M. Nguyen, T. Tang SLAC National Accelerator Laboratory, Menlo Park, United States
O18-5 A Hybrid Solid State Marx Magnetron Modulator R. L. Cassel Stangenes Industries, Inc., Palo Alto, CA, United States
O18-6 Transient Thermal Response of Pulsed Power Electronic Packages N. R. Jankowski1, 2, F. P. McCluskey2 1Sensors and Electron Devices Directorate, U.S. Army Research Laboratory, Adelphi, MD, United States 2Department of Mechanical Engineering, University of Maryland, College Park, MD, United States
O18-7 A Hierarchical Control Architecture for a PEBB-based ILC Marx Modulator K. Macken, C. Burkhart, R. Larsen, M. Nguyen, J. Olsen SLAC National Accelerator Laboratory, Menlo Park, United States
O18-8 Nanosecond High Voltage Pulse Generators PROTEUS without
High-Voltage Gas or Semiconductor Switch A. N. Maltsev1, I. R. Arslanov2, V. V. Chupin2, A. Y. Ivanov2, D. Y. Kolokolov2, I. N. Lapin2 1Institute of Atmospheric Optics Russian Academy of Sciences, Tomsk, Russian Federation 2Electrodinamic Systems & Technologies, LLC, Tomsk, Russian Federation
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Thursday July 2 9:15 - 11:15 Ballroom Session Chairs: Dan Schweickart
Air Force Research Laboratory Susan L. Heidger Air Force Research Laboratory (AFRL/RDHP)
Session O19: Breakdown Phenomena in Gases, Liquids &
Solids O19-1 Insulator Surface Flashover Due to Ultra-Violet Illumination
J. B. Javedani, T. L. Houck, D. A. Lahowe, G. E. Vogtlin, D. A. Goerz Engeineering, Lawrence Livermore National Laboratory, Livermore, CA, United States
O19-2 Optical Emission Diagnostics of the Plasma Channel in the Pulsed Electrical Discharge in Gas Bubbles S. Gershman1, A. Belkind1, K. Becker2 1A. Belkind & Associates, LLC, North Plainfield, NJ, United States 2Polytechnic Institute of New York University, Brooklyn, NY, United States
O19-3 An In-Depth Investigation into the Effect of Oil Pressure on the Complete Statistical Performance of a High Pressure, Flowing Oil Switch* P. Norgard, R. D. Curry Center for Physical and Power Electronics, University of Missouri-Columbia, Columbia, MO, United States
O19-4 Generation of Discharge Plasma in Water by High Repetition Rate Pulsed Power Modulator K. Kouno1, T. Sakugawa1, K. Kawamoto1, S. H. R. Hosseini1, S. Katsuki1, H. Akiyama1, Z. Li2 1Graduate School of Science and Technology, Kumamoto University , Kumamoto, Japan 2Electrical Engineering, Toyo University, Kawagoe, Japan
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O19-5 VUV Emission from Dielectric Surface Flashover at Atmospheric Pressure T. G. Rogers1, A. Neuber1, G. Laity1, K. Frank1, J. Dickens1, T. Schramm2 1Center for Pulsed Power and Power Electronics, Texas Tech University, Lubbock, Texas, United States 2Department of Physics, Am Hubland, D-97074 Wuerzburg, Germany
O19-6 Pulsed Breakdown Characterization of Advanced Liquid Dielectrics for High-Power, High-Pressure, Rep-Rate Oil Switching* C. Yeckel, R. D. Curry Center for Physical and Power Electronics, University of Missouri-Columbia, Columbia, MO, United States
O19-7 Time Resolved Imaging of a Pulsed Plasma Discharge in Water P. Ceccato, O. Guaitella, A. Rousseau LPP Ecole Polytechnique, Palaiseau, France
O19-8 Dynamic Arc Modeling of Pollution Flashover Process on HV Insulators under AC Voltage M. K. Mohamed Ali Mr. Mustafa Khalil Mohamed Ali, Cairo, Egypt
Thursday July 2 9:15 - 11:15 Colonial Session Chair: Naz E. Islam
University of Missouri - Columbia Session O20: Industrial, Commercial, & Medical Applications O20-1 Near-Field Imaging of Tumor Tissue with Sub-Nanosecond
Electrical Pulses S. Xiao1, C. E. Baum2, K. H. Schoenbach1 1Old Dominion University, Frank Reidy Research Center for Bioelectrics, Norfolk, VA, United States 2University of New Mexico, Department of Electrical
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and Computer Engineering, Albuquerque, NM, United States
O20-2 Bioelectric Studies with Subnanosecond Pulsed Electric Fields J. T. Camp1, X. Shu1, S. Beebe1, P. F. Blackmore2, K. H. Shoenbach1 1Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, United States 2Eastern Virginia Medical School, Norfolk, VA, United States
O20-3 Direct Versus Capacitive Coupling in Cell Electroporation Experiments D. M. French1, R. M. Gilgenbach1, Y. Y. Lau1, M. D. Uhler2 1Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI, United States 2Biological Chemistry, University of Michigan, Ann Arbor, MI, United States
O20-4 Thermal and Non-Thermal Effects of Intense Burst Sinusoidal Electric Fields on HeLa Cells S. Katsuki1, K. Mitsutake2, N. Nomura2, M. Hirakawa2, K. Abe2, K. Morotomi2, K. -I. Yano1, H. Akiyama1, T. Shuto3, H. Kai3 1Bioelectrics Research Center, Kumamoto University, Kumamoto, Japan 2Graduate School of Science and Technology, Kumamoto University, Kumamoto, Japan 3Faculty of Medical and Pharmaceutical Sciences, Kumamoto Universit, Kumamoto, Japan
O20-5 Tumor Treatment with Nanosecond Pulsed Electric Fields
J. F. Kolb, X. Chen, J. Zhuang, W. Ren, S. J. Beebe, K. H. Schoenbach Frank Reidy Research Center for Bioelectrics, Old Dominion University, VA, United States
O20-6 Low Energy Nanosecond Pulsed Plasma Disinfection Needle C. Jiang1, M. T. Chen1, C. Schaudinn2, A. Gorur2, P. P. Sedghizadeh2, J. W. Costerton2, P. T. Vernier1, M. A. Gundersen1 1Department of EE-Electrophysics, University of Southern California, Los Angeles, CA, United States 2Center for Biofilms, School of Dentistry, University of Southern California, Los Angeles, CA, United States
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O20-7 Decontamination of Wastewater by Pulsed Electric Field Treatment: a Critical Evaluation C. A. Gusbeth1, W. Frey1, G. Mller1, T. Schwartz2 1IHM, Forschungszentrum Karlsruhe GmbH, Karlsruhe, Germany 2ITC-CPV, Forschungszentrum Karlsruhe GmbH, Karlsruhe, Germany
O20-8 Multi-Electrode Electrohydraulic Discharge for Sterilization and Disinfection Y. Huang, H. Yan, S. Li, K. Yan Department of Environmental Science, Zhejiang University, Hangzhou, China
Thursday July 2 11:15 - 12:30 East/State Poster Sessions Session Chairs: Aaron Dougherty Naval Research Laboratory
Zach Shotts Radiance, Inc. Session 03P: Industrial, Commercial, & Medical Applications
and Explosive and Compact Pulsed Power
03P-1 Energy Deposition Assessment and Electromagnetic
Evaluation of Electroexplosive Devices in a Pulsed Power Environment J. Parson, J. Dickens, J. Walter, A. Neuber Electrical and Computer Engineering, Texas Tech University, Lubbock, TX, United States
03P-2 Experiments on a 1-MA Linear Transformer Driver R. M. Gilgenbach1, M. R. Gomez1, J. C. Zier1, D. M. French1, Y. Y. Lau1, M. G. Mazarakis2, M. E. Cuneo2, B. V. Oliver2, T. A. Mehlhorn2 1Nuclear Eng. & Rad. Sciences, University of Michigan, Ann Arbor, MI, United States 2Sandia National Labs, Albuquerque, NM, United States
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03P-3 A Compact 5kV Battery-Capacitor Seed Source with Rapid Capacitor Charger S. L. Holt1, J. C. Dickens1, J. L. McKinney1, M. Kristiansen1, L. L. Altgilbers2 1Center for Pulsed Power and Power Electronics, Texas Tech University, Lubbock, TX, United States 2Space and Missile Defense Command, United States Army, Huntsville, AL, United States
03P-4 Limits and Failure Modes in High Voltage Vector Inversion Generators Z. S. Roberts, Z. D. Shotts, M. F. Rose Radiance Technologies, Huntsville, Alabama, United States
03P-5 High Voltage Solid State Switched Vector Inversion Generator for HPM Applications Z. D. Shotts, M. F. Rose Radiance Technologies, Huntsville, Alabama, United States
03P-6 A Compact Nested High Voltage Generator for Medium Pulse Duration Applications J. A. Gilbrech, R. J. Adler, F. K. Childers, M. Hope, E. Koschmann Applied Energetics, Tucson, AZ, United States
03P-7 High-Power Compact Capacitor Charger M. G. Giesselmann, T. T. Vollmer Pulsed Power & Power Electronics, Texas Tech University, Lubbock, TX, United States
03P-8 Compact Solid State Variable Amplitude High Repetition Rate Pulse Generator S. J. Pendleton1, D. Singleton2, A. Kuthi2, M. A. Gundersen1, 2 1Physics, University of Southern California, Los Angeles, CA, United States 2Electrical Engineering - Electrophysics, University of Southern California, Los Angeles, CA, United States
03P-9 A 15 kA Linear Transformer Driver* D. Matia, M. Giesselmann, A. Neuber, M. K. Kristiansen Center for Pulsed Power and Power Electronics Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, TX, United States
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03P-10 Design and Performance of an Ultra-Compact 1.8 kJ, 600 kV Pulsed Power System C. Nunnally, J. R. Mayes, C. W. Hatfield, J. D. Dowden Applied Physical Electronics LC, Austin, TX, United States
03P-11 Development of a Sequentially Switched Marx Generator for HPM Loads J. R. Mayes, C. W. Hatfield Applied Physical Electronics, L.C., Austin, TX, United States
03P-12 A New, Compact Pulsed Power System Based on Surge Arrestor Technology M. C. Clark Collins Clark Technologies Inc., Albuquerque, New Mexico, United States
03P-13 Compact, DC-Powered 100Hz, 600kV Pulsed Power Source M. B. Lara, J. R. Mayes, C. Nunnally, T. A. Holt Applied Physical Electronics, Austin, TX, United States
03P-14 Nanosecond FID Pulse Generator with Amplitude of 10 kV and PRF of 3.3 MHz V. M. Efanov, M. V. Efanov, A. V. Kriklenko, N. K. Savastianov FID GmbH, Burbach, Germany
03P-15 Disk Magneto-Cumulative Energy Sources for X-Ray Complex EMIR V. A. Demidov, A. S. Boriskin, S. A. Kazakov, A. A. Agapov, Y. V. Vlasov, R. M. Garipov, S. N. Golosov, N. P. Kazakova, S. V. Kutumov, Y. N. Lashmanov, A. N. Moiseenko, L. N. Plyashkevich, S. E. Pavlov, A. P. Romanov, A. S. Sevastyanov, O. M. Tatsenko, A. V. Filippov, E. V. Shapovalov, E. I. Schetnikov, V. A. Yanenko Scientific and Technical Center of Physics, Russian Federal Nuclear Center - VNIIEF, Sarov, Nizhny Novgorod Region, Russian Federation
03P-16 Design of a Compact Power Conditioning Unit for Use with an Explosively Driven High Power Microwave System J. Korn1, A. Young1, C. Davis1, A. Nueber1, M. Kristiansen1, L. Altgilbers2
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1The Center for Pulsed Power and Power Electronics, Texas Tech University, Lubbock, TX, United States 2SMDC, U.S. Army, Huntsville, AL, United States
03P-17 Power Conditioning Opimization for a Flux Compression Generator Using a Non-Explosive Testing System C. B. Davis, A. Young, A. A. Neuber, J. C. Dickens, M. Kristiansen Center for Pulsed Power and Power Electronics, Texas Tech University, Lubbock, TX, United States
03P-18 An Innovative and Non-Invasive Technology for Food Processing B. M. Novac, P. Sarkar, I. R. Smith, C. Greenwood Electronic and Electrical Engineering, Loughborough University, Loughborough, Leicestershire, United Kingdom
03P-19 Current Pulse Effects on Damage Experiments in a Cylindrical Geometry A. M. Kaul Applied Physics Division, Los Alamos National Laboratory, Los Alamos, NM, United States
03P-20 Pulsed Electric Field Effects on the Germination Rate of Sicklepod and Yellow Nutsedge Seeds R. Bokka, S. Li, H. Kirkici Electrical Engineering, Auburn University, Auburn, AL, United States
03P-21 Estimated Electrical Power Delivery to a Plasma Channel Formed in a Water Gap. M. J. Given, I. Timoshkin, M. P. Wilson, S. J. Macgregor Department of Electronic and Electrical Engineering, University of Strathclyde, Glasgow, United Kingdom
03P-22 Detection of the Onset of Pore Formation by Nanosecond-Time-Resolution Pulsed Laser Fluorescence Microscopy Measurements on Plant Cell Protoplasts W. Frey, T. Berghoefer, B. Flickinger IHM, Forschungszentrum Karlsruhe, Eggenstein-Leopoldshafen, Germany
03P-23 Investigation of Drift Dynamics and Injection Stability of High-Current Electron Beam with Picosecond Resolution M. I. Yalandin1, A. G. Reutova1, K. A. Sharypov1, V. G. Shpak1, S. A. Shunailov1, M. R. Ulmasculov1, G. A. Mesyats2
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1Institute of Electrophysics, Ural Branch of Russian Academy of Sciences, Ekaterinburg, Russian Federation 2Lebedev Physical Institute RAS, Moscow, Russian Federation
03P-24 Atmospheric Glow Discharge Plasmas Using a Microhollow Cathode Device* A. Lodes, R. D. Curry Center for Physical and Power Electronics, University of Missouri-Columbia, Columbia, MO, United States
03P-25 Pulse Power System for Waste Water Cleaning Y. Y. Livshiz, O. Gafri Chief Technological Officer WADIS Ltd, Rehovot, Israel
03P-26 Application of Pulsed Power System for Water Treatment of the Leachate H. J. Ryoo1, Y. S. Jin1, S. R. Jang2, S. H. Ahn2, G. H. Rim1 1Industry Application Research Division, KERI, Changwon, South Korea 2Dept. of Energy Conversion Technology, University of Science & Technology, Daejeon, South Korea
03P-27 The Optimal Design and Comparison of Power Supply for Dielectric Barrier Discharge Ozone Reactor B. Kim, H. Ju, K. Ko Electric Engineering Department, Hanyang University, Seoul, South Korea
03P-28 Ozone Synthesis Using Streamer Discharge Produced by Ns Pulse Voltage under Atmospheric Pressure K. Takaki1, S. Mukaigawa1, T. Fujiwara1, T. Go2 1Faculty of Engineering, Iwate University, Morioka, Iwate, Japan 2Ichinoseki National College of Technology, Ichinoseki, Iwate, Japan
03P-29 Development of Compact Ozonizer Using Wire to Plate Electrodes S. Ueda1, F. Tanaka1, K. Kouno1, M. Akiyama1, T. Sakugawa1, H. Akiyama1, Y. Kinoshita2 1Graduate School of Science and Technology, Kumamoto University, Kumamoto, Japan 2Toyota Motor Corporation, Susono, Japan
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03P-30 Spectral and Optical Investigations of Electric Arc Alternating Current Plasma Generators Using Carbon Dioxide as a Plasma Forming Agent P. G. Rutberg, A. V. Nikonov, R. V. Ovchinnikov, A. V. Pavlov, S. D. Popov, E. O. Serba, V. A. Spodobin, A. V. Surov Institute of Electrophysic and Electricpower RAS, Saint-Petersburg, Russian Federation
03P-31 Investigation of Electrode Units of Alternating Current Plasma Generators. Ways of Increase in Lifetime of Operation and Durability. V. E. Kuznetsov, A. A. Safronov, I. I. Kumkova, R. V. Ovchinnikov, V. N. Shiryev, K. A. Kuzmin, O. B. Vasilieva IEERAS, St. Petersburg, Russian Federation
03P-32 Nitric Oxide Generated by Atmospheric Pressure Air Microplasma K. Matsuo Science and Technology, Kumamoto University, Kumamoto, Japan
03P-33 The Electric Arc Alternating Current Plasma Generator on Steam-Air Mixtures for Plasmachemical Applications P. G. Rutberg, S. D. Popov, A. V. Surov, E. O. Serba, A. V. Nikonov, A. V. Pavlov, I. I. Kumkova, O. B. Vasilieva Institute for Electrophysics and Electric Power, Russian Academy of Sciences, St. Petersburg, Russian Federation
03P-34 Intracellular DNA Damage in CHO Cells Induced by Application of Burst RF Fields M. Yano1, N. Nomura1, K. Abe1, S. Katsuki2, H. Akiyama2 1Graduate School of Science and Technology, Kumamoto University, Kumamoto, Japan 2Bioelectrics Research Center, Kumamoto University, Kumamoto, Japan
03P-35 Pulsed Electric Field Induced Changes in Dielectric Properties of Biological Cells J. Zhuang, S. J. Beebe, K. H. Schoenbach, J. F. Kolb Frank Reidy Research Center for Bioelectrics, Old Dominion University, VA, United States
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03P-36 Sensitivity of Some Biological Tissues and Cellular Cultures to Repetitive Sub-Microsecond Microwaves V. V. Rostov1, M. A. Bolshakov1, I. R. Knyazeva1, O. P. Kutenkov1, L. P. Zharkova1, M. A. Buldakov2, N. V. Litvyakov2, N. V. Cherdyntseva2 1Russian Academy of Sciences, High Current Electronics Institute, Tomsk, Russian Federation 2Russian Academy of Medical Sciences, Institute of Oncology, Tomsk, Russian Federation
03P-37 Pulse-Modulated Microwaves Propagation Inside of a 3D Non-Coordinate Shape Heart Model S. Asmontas1, L. Nickelson1, R. Martavicius2, V. Engelson3 1Terhertz's Electronic Laboratory, Semiconductor Physics Institute, Vilnius, Lithuania 2Electronic System Department, Gediminas Technical University, Vilnius, Lithuania 3Department of Computer Science, Linkoping University, SE-58183, Linkoping, Sweden
03P-38 Spectroscopy of Non-Thermal Atmospheric Helium Plasma Needle B. Onyenucheya, T. M. DiSanto, J. L. Zirnheld, K. M. Burke Energy Systems Institute, University at Buffalo, Buffalo, NY, United States
03P-39 Study on the High Frequency High Voltage Power Supply Used for Leak Inspection Y. Sun1, P. Yan1, Y. Gao1, J. Shao2 1Institute of Electrical Engineering ,Chinese Academy of Sciences, Beijing, China 2School of Physical Science and Technology, Huanggang Normal University, Huanggang, Hubei, China
03P-40 Effect of Frequency of Burst Pulse High Electric Field and Burst Pulse High Intensity Electromagnetic Wave on Microorganisms Y. Minamitani, Y. Kuramochi, T. Saito, T. Ueno Graduate School of Science and Engineering, Yamagata University, Yonezawa, Yamagata, Japan
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03P-41 Investigation of Operating Modes of Electric Arc Alternating Current Plasma Generators Using Carbon Dioxide as a Plasma Forming Agent P. G. Rutberg, A. A. Safronov, A. V. Surov, S. D. Popov, G. V. Nakonechny, R. V. Ovchinnikov, V. A. Spodobin, S. A. Lukyanov, S. A. Kuschev Institute for Electrophysics and Electric Power, Russian Academy of Sciences, St. Petersburg, Russian Federation
03P-42 The Effect of Spraying of Water Droplets and Location of Water Droplets on the Water Treatment by Pulsed Discharge in Air T. Kobayashi1, T. Handa1, Y. Minamitani1, Y. Tashima2, T. Nose2 1Graduate School of Science and Engineering, Yamagata University, Yonezawa, Japan 2Sekisui Chemical Co., Ltd., Kyoto, Japan
03P-43 Efficient Streamer Plasma Generation A. J. M. Pemen, G. J. J. Winands, Z. Liu, E. J. M. V. Heesch, T. H. P. Ariaans Electrical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands
03P-44 Exhaust Gas Treatment by 5ns Pulse Generator T. Matsumoto1, D. Wang2, T. Namihira3, H. Akiyama3 1Department of Computer Science and Electrical Engineering, Kumamoto University, Kurokami 2-39-1, Kumamoto, Japan 2Priority Organization for Innovation and Excellence, Kumamoto University, Kurokami 2-39-1, Kumamoto, Japan 3Bioelectrics Research Center, Kumamoto University, Kurokami 2-39-1, Kumamoto, Japan
03P-45 Consideration of Parallel and Serial Coaxial Reactors for NOx Treatment by Nanosecond Pulsed Power Discharge F. Fukawa1, N. Shimomura1, S. Yamanaka1, T. Yano1, Y. Yokote1, K. Teranishi1, H. Akiyama2, H. Itoh3 1The University of Tokushima, Tokushima, Japan 2Kumamoto University, Kumamoto, Japan 3Chiba Institute of Technology, Narashino, Chiba, Japan
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03P-46 Pulsed Discharge Plasma Generated by Nano-Seconds Pulsed Power in Atmospheric Air D. Wang1, T. Namihira2, H. Akiyama3 1Priority Organization for Innovation and Excellence, Kumamoto University, Kumamoto, Japan 2Bioelectrics Research Center, Kumamoto University, Kumamoto, Japan 3Graduate School of Science and Technology, Kumamoto University, Kumamoto, Japan
03P-47 Purification of High Conductive Liquid Using Gas-Liquid Phases Discharge Reactor K. Takahashi1, Y. Sasaki2, S. Mukaigawa1, K. Takaki1, T. Fujiwara1, N. Satta2 1Faculty of Engineering, Iwate University, Iwate, Japan 2Faculty of Agriculture, Iwate University, Iwate, Japan
03P-48 Improvement of Efficiency for Decomposition of Organic Compound in Water Using Pulsed Streamer Discharge in Air with Water Droplets by Increasing of Residence Time T. Sugai, T. Abe, Y. Minamitani Graduate School of Science and Engineering, Yamagata University, Yonezawa, Japan
03P-49 TEM and EDX Analysis of Bacterial Spores Treated by Nanosecond Pulsed Electric Fields K. Arikawa1, J. Choi1, T. Namihira2, T. Sakugawa1, S. Katsuki2, H. Akiyama1, H. Seta3, X. Y. Shan3, N. Ando3 1Graduate School of Science and Technology, Kumamoto University, Kumamoto, Japan 2Bioelectrics Research Center, Kumamoto University, Kumamoto, Japan 3Product Development Center, Suntory LTD., Kawasaki, Japan
03P-50 Shielding Effectiveness of Low Temperature Plasma Screen S. S. M. Chung1, 2, J. W. Lan1, H. Y. Lin3, S. H. Cheng4, T. W. Suen5 1Department of Electronics Engineering, Southern Taiwan University of Technology, Tainan, Taiwan 2Center for Micro/Nana Science and Technology, National Cheng Kung University, Tainan, Taiwan 3Mechanical and System Research Laboratory, Industrial Technology Research Institute, Hsinchu, Taiwan
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4Institute of Nuclear Energy Research, Atomic Energy Commission, Taoyuan, Taiwan 5Electronic Research Division, Chung-Shan Institute of Science and Technology, Taoyuan, Taiwan
03P-51 Parametric Studies of an Electrohydrodynamic Plasma Actuator for Boundary Layer Flow Control T. Hurtig, P. Appelgren, A. Larsson Defence & Security Systems and Technology, Swedish Defence Research Agency, Stockholm, Sweden
03P-52 Radiation Hardness of Avalanche Diodes and Gas Discharge Tubes Used for Transient Voltage Suppression M. Vujisic1, K. Stankovic2, V. Vukic3 1Faculty of Electrical Engineering, University of Belgrade, Belgrade, Serbia 2Institute of Nuclear Sciences, Belgrade, Serbia 3Electrical Engineering Institute, Belgrade, Serbia
03P-53 Optimization of Discharge Condition for Recycling Aggregate by Pulsed Discharges Inside of Concrete D. Wang1, S. Inoue2, J. Araki2, T. Aoki3, S. Maeda2, S. Iizasa2, M. Takaki2, T. Namihira4, M. Shigeishi2, M. Ohtsu2, H. Akiyama2 1Priority Organization for Innovation and Excellence, Kumamoto University, Kumamoto, Japan 2Graduate School of Science and Technology, Kumamoto University, Kumamoto, Japan 3Department of Computer Science and Electrical Engineering, Kumamoto University, Kumamoto, Japan 4Bioelectrics Research Center, Kumamoto University, Kumamoto, Japan
03P-54 Electrohydraulic Shock Wave Generation as a Mean to Increase Intrinsic Permeability of Concrete T. Reess1, A. De Ferron1, O. Maurel2, W. Chen2, M. Matallah2, C. Laborderie2, G. Pijaudier2, F. Reybethbeder3, A. Jacques3, J. Lassus3 1Laboratoire de Genie Electrique, University of Pau, Pau, France 2IPRA, University of Pau, Pau, France 3TOTAL, Pau, France
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03P-55 Breakdown Characteristics of Argon in Partial Vacuum under High Frequency Pulsed Voltage with Varying Duty Cycle M. Lipham, H. Zhao, S. Li, H. Kirkici Electrical and Computer Engineering, Auburn University, Auburn, AL, United States
03P-56 Improvement of Polyphenols Extraction from Grape Pomace Using Pulsed Arc Electro-Hydraulic Discharges N. Boussetta1, A. Silvestre de Ferron2, T. Reess2, L. Pecastaing2, J. L. Lanoiselle1, E. Vorobiev1 1Université Technologique de Compiègne, Unité de Transformations intégrées de la Matière Renouvelable, Compiègne, France 2Université de Pau, Laboratoire de Génie Electrique, Pau, France
03P-57 Fruit Body Formation of Basidiomycete by Pulse Electric Field Stimulations K. Takaki1, N. Yamazaki1, S. Mukaigawa1, T. Fujiwara1, H. Kofujita2, Y. Sakamoto3, K. Takahasi4, M. Narimatsu5, K. Nagane6 1Faculty of Engineering, Iwate University, Morioka, Iwate, Japan 2Faculty of Agriculture, Iwate University, Morioka, Iwate, Japan 3Microorganism Application Research Department, Iwate Biotechnology Research Center, Kitakami, Iwate, Japan 4Morioka Forest Association, Morioka, Iwate, Japan 5Tono Agricultural and Forestry Center, Tono, Iwate, Japan 6Nagane Co. Ltd., Kunohe, Iwate, Japan
03P-58 Effects of Nanosecond Pulsed Electric Field on the Embryonic Development of Medaka Fish Egg (Oryzias Latipes) D. K. Kang1, S. Nakamitsu1, S. Iwasaki1, S. H. R. Hosseini1, S. Kono2, N. Tominaga2, T. Sakugawa1, S. Katsuki1, H. Akiyama1 1Graduate School of Science and Technology, Kumamoto University, Kumamoto, Japan 2Ariake National College of Technology, Omuta, Japan
03P-59 Operation of an Electroporation Device for Mash M. Sack1, J. Sigler2, C. Eing1, L. Stukenbrock2, R. Staengle1, A. Wolf1, G. Mueller1
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1Forschungszentrum Karlsruhe, Eggenstein-Leopoldshafen, Germany 2Staatliches Weinbauinstitut, Freiburg, Germany
03P-60 Promotion of Germination Using Pulsed Electric Field S. Ihara, R. Inuzuka, C. Yamabe Department of Electrical and Electronic Engineering, Faculty of Science and Engineering, Saga University, Saga, Japan
03P-61 Isolated Power Supply for Self-Neutralization Tests of a Ferroelectric Plasma Thruster B. T. Hutsel, S. D. Kovaleski, J. W. Kwon Dept. of Electrical and Computer Engineering, University of Missouri, Columbia, MO, United States
03P-62 Flashover Prevention of High Voltage Piezoelectric Transformers A. Benwell, S. D. Kovalesko, J. W. Kwon, T. Wacharasindhu, E. Baxter Electrical and Computer Engineering, University of Missouri - Columbia, Columbia, MO, United States
03P-63 Spectral Diagnosis of Plasma Jet at Atmospheric Pressure X. L. Tang1, 2, 3, G. Qiu1,2,3, X. P. Wang4, X. P. Feng4 1Plasma & Surface Research Center, College of Science, Donghua University, Shanghai 201620, China 2National Engineering Research Center for Dyeing and Finishing of Textiles, Shanghai 201620, China 3College of Material Science and Engineering, Donghua University, Shanghai 201620, China 4Department of Physics, University of Puerto Rico, San Juan, P. R. 00931-3343, Puerto Rico
03P-64 The Effects of Collection Plate Area with Electrostatic Flows Resulting from Multiple Corona Discharges J. D. Kribs, M. S. June, K. M. Lyons Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC, United States
03P-65 Toxicity of Direct Non-Thermal Atmospheric Pressure Plasma Treatment of Living Tissue S. Kalghatgi1, D. Dobrynin2, A. Wu3, E. Podolsky3, E. Cerchar3, G. Fridman4, A. Fridman2, A. Brooks3, K. Barbee4, G. Friedman1
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1Department of Electrical and Computer Engineering, Drexel University, Philadelphia, United States 2Department of Mechanical Engineering, Drexel University, Philadelphia, United States 3Department of Surgery, Drexel University College of Medicine, Philadelphia, United States 4School of Biomedical Engineering, Drexel University, Philadelphia, United States
03P-66 Experimental Investigations of Ring-Shaped Plasma Bullets Emitted by a Pulsed Plasma Jet M. Laroussi, E. Karakas, A. Begum Laser & Plasma Engineering Institute, Old Dominion University, Norfolk, VA, United States
03P-67 On the Interaction of Non-Thermal Atmospheric Pressure Plasma with Tissues S. Kalghatgi1, C. Kelly2, E. Cerchar3, R. Sensenig3, A. Brooks3, A. Fridman4, A. Morss-Clyne4, J. Azizkhan-Clifford2, G. Friedman1 1Department of Electrical and Computer Engineering, Drexel University, Philadelphia, United States 2Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, United States 3Department of Surgery, Drexel University College of Medicine, Philadelphia, United States 4Department of Mechanical Engineering, Drexel University, Philadelphia, United States
Thursday July 2 13:30 - 14:45 East/State Session Chairs: Donald Paul Murphy
Naval Research Laboratory Joshua Leckbee Sandia National Laboratories James Dickens Texas Tech University
Session 04P: Pulsed Power Sources, Pulsed Power
Systems, Diagnostics, and Power Electronics & Systems
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04P-1 Beam Loading in the Darht Second Axis Induction Cells K. Nielsen1, D. Dalmas1, J. Johnson1, R. Temple1, B. Prichard2, C. Y. Tom3 1Hydrodynamic Experiments, Los Alamos National Lab, Los Alamos, NM, United States 2SAIC, Los Alamos, NM, United States 3NSTEC, Los Alamos, NM, United States
04P-2 Modulate the Pulse Shape by Varying Volt-Second Products in LTD L. Zhou, J. Deng, L. Chen, W. Zou Institute of Fluid Physics, CAEP, Sichuan, China
04P-3 Comparison of the Performance of the Upgraded Z with Circuit Predictions K. W. Struve1, L. F. Bennett1, J. -P. Davis1, D. D. Hinshelwood2, M. E. Savage1, B. S. Stoltzfus1, T. C. Wagoner3 1Pulsed Power Sciences Center, Sandia National Laboratories, Albuquerque, NM, United States 2Plasma Physics Division, Naval Research Laboratory, Washington, DC, United States 3Pulsed Power Department, Ktech Corporation, Albuquerque, NM, United States
04P-4 ZR-Convolute Analysis and Modeling: Plasma Evolution and Dynamics Leading to Current Losses D. V. Rose1, D. R. Welch1, R. E. Clark1, E. A. Madrid1, C. L. Miller1, C. B. Mostrom1, W. A. Stygar2, B. M. Jones2, K. W. Struve2, M. E. Cuneo2 1Voss Scientific, LLC, Albuquerque, NM, United States 2Sandia National Laboratories, Albuquerque, NM, United States
04P-5 Current Loss in the Vacuum Section of the Refurbished Z Accelerator T. D. Pointon, D. B. Seidel Sandia National Laboratories*, NM, United States
04P-6 An Optimization Study of Stripline Loads for Isentropic Compression Experiments D. B. Seidel, W. L. Langston, M. D. Knudson, R. W. Lemke, J. -P. Davis, T. D. Pointon Sandia National Laboratories*, Albuquerque, NM, United States
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04P-7 Numerical Simulations of Power Flow in Magnetically Insulated Transmission Lines Driving Z-Pinch Loads S. W. Vickers1, J. Chittenden2 1United Kingdom, AWE, Aldermaston, United Kingdom 2Plasma Physics, Imperial College, London, United Kingdom
04P-8 Conversion of Mercury (a 2-TW Inductive Voltage Adder) to Positive Polarity* R. J. Allen1, C. L. Berry2, R. J. Commisso1, E. Featherstone2, R. Fisher2, G. Cooperstein1, D. D. Hinshelwood1, S. L. Jackson3, A. T. Miller2, P. F. Ottinger1, D. G. Phipps1, J. W. Schumer1 1Plasma Physics Division, Naval Research Laboratory, Washington, DC, United States 2Titan Group, L-3 Communications, Reston, VA, United States 3National Research Council, Washington, DC, United States
04P-9 Benchmarking and Implementation of a Generalized MITL Flow Model P. F. Ottinger, J. W. Schumer, H. D. David, A. J. Allen Plasma Physics Division, Naval Research Laboratory, Washington, DC, United States
04P-10 A Stacked Transformer Modulator that Delivers High Voltage at High Rep-Rate and Duty Factor G. Saewert, H. Pfeffer Fermi National Accelerator Laboratory
04P-11 Development Concept of High-Current Accelerators with High Pulse Repetition Frequency Within Wide Range of Output Parameters. A. V. Gunin, V. V. Rostov, A. S. Stepchenko, V. V. Gubanov, V. N. Kiselev SB RAS, Institute of High Current Electronics, Tomsk, Russian Federation
04P-12 Development of a 1-MV, 1-MA, Rep-Rate Linear Transformer Driver at SNL K. R. LeChien1, M. G. Mazarakis1, W. E. Fowler1, W. A. Stygar1, A. A. Kim2 1Sandia National Laboratories, Albuquerque, NM, United States 2High Current Electronics Institute, Tomsk, Russia
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04P-13 High Voltage Semiconductor Pulsed Generator for Producing the Oxide Nanostructures Water Dispersions P. G. Rutberg1, I. V. Grekhov2, V. A. Kolikov1, S. V. Korotkov2, I. A. Rolnik2, V. N. Snetov1, A. Y. Stogov1 1Institute for Electrophysics and Electric Power Russian Academy of Science, St. Petersburg, Russian Federation 2Ioffe Physico-Technical Institute Russian Academy of Science, St. Petersburg, Russian Federation
04P-14 Damping Resonant Current in a Spark-Gap Trigger Circuit to Reduce Noise E. L. Ruden1, D. J. Brown2, T. C. Grabowski2, C. W. Gregg2, B. M. Matinez2, J. V. Parker2, J. F. Camacho3, S. K. Coffey3, P. Poulsen4 1Directed Energy Directorate, Air Force Research Laboratory, Kirtland AFB, NM, United States 2Science Applications International Corporation, Albuquerque, NM, United States 3NumerEx, LLC, Albuquerque, NM, United States 4CARE’N Co., Livermore, CA, United States
04P-15 A MV Marx Generator Modified for Nanosecond Risetime T. A. Holt, M. B. Lara, J. R. Mayes, M. G. Mayes Applied Physical Electronics, L. C., Austin, TX, United States
04P-16 A Modular PFN Marx with a Unique Charging System and Feedthrough D. T. Price, R. J. Adler, J. A. Gilbrech Applied Energetics, Tucson, AZ, United States
04P-17 125kV, 100kA, 150ns, 5pps Test Facility with Solid State Switched Distributed Pulse Compression Marx S. C. Glidden, H. D. Sanders Applied Pulsed Power, Inc., Freeville, NY, United States
04P-18 Repetitive Auto-Triggered Marx Generator for an Ultra Wideband Source B. Cassany1, P. Modin1, B. Cadilhon1, A. Silvestre de Ferron2 1Div. DEV/SEMR/LSRV, CEA DAM, Le Barp, France 2Electrical Engineering Laboratory, Pau University, France
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04P-19 Experimental Results on Design Aspects of a Compact Repetitive Marx Generator A. Sharma, S. Mitra, S. K., V. Sharma, K. V. Nagesh, D. P. Chakravarthy, P. D. P., A. K. Ray Accelerator & Pulse Power Div., Bhaba Atomic Research Centre, Mumbai, Maharashtra, India
04P-20 Investigation of Spark Gap Discharges in a Regime of Very High Repetition Rate H. Rahaman1, S. H. Nam1, S. H. Kim1, S. S. Park1, S. H. Kim1, H. Heo1, O. R. Choi1, S. C. Kim1, K. Frank2 1Pohang Accelerator Laboratory, Pohang, South Korea 2Center for Pulsed Power and Power Electronics, Texas Tech University, Texas, United States
04P-21 Compact All Solid State Pulsed Power Generator Driven by FPGA M. Akiyama1, K. Kouno1, K. Kawamoto1, T. Sakugawa1, H. Akiyama1, K. Suematsu2, A. Kouda2, M. Watanabe2 1Kumamoto Univercity, Graduate School of Science and Technology, Kumamoto, Japan 2Suematsu Electronics Co. Ltd., Kumamoto, Japan
04P-22 A Compact, Low Jitter, Fast Rise Time, Gas-Switched Pulse Generator System with High Pulse Repetition Rate Capability R. J. Focia1, C. A. Frost2 1Pulsed Power Laboratories, Inc., Edgewood, NM, United States 2Pulse Power Physics, Inc., Albuquerque, NM, United States
04P-23 An All Solid-State Pulsed Power Generator with Semiconductor and Magnetic Compression Switches K. Liu, D. Wang, J. Qiu Institute of Electrical Light Sources, Fudan University, Shanghai, China
04P-24 Compact and RepetitiveTesla-Based Power Source B. M. Novac, P. Sarkar, I. R. Smith, C. Greenwood Electronic and Electrical Engineering, Loughborough University, Loughborough, Leicestershire, United Kingdom
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04P-25 Testing a Scaled Pulsed Modulator for an IEC Neutron Source into a Resistive Load G. E. Dale, R. M. Wheat, R. Aragonez ISR-6, Los Alamos National Laboratory, Los Alamos, NM, United States
04P-26 Pulse Power Electromagnetic Fields, Rep-Rate Influence on Electromagnetic Effects L. Palisek, L. Suchy VTUPV Vyskov, VOP-026 Sternberk, s.p., Sternberk, Czech Republic
04P-27 A High Voltage Power Converter with a Frequency and Voltage Controller S. Zabihi1, F. Zare1, H. Akiyama2 1QUT, Brisbane, Australia 2Kumamoto University, Kumamoto, Japan
04P-28 High Voltage Pulsed Power Using a Current Source for a Plasma System S. Zabihi1, F. Zare2, H. Akiyama2 1Engineering Systems, QUT, Brisbane, Australia 2Pulsed Power, Kumamoto University, Kumamoto, Japan
04P-29 Design and Construction of a Corona Charged High Power Impulse Generator F. Vega1, 2, N. Mora1, F. Roman1, N. Peña3, F. Rachidi2, B. Daout4 1National University of Colombia - EMC UN, Bogota, Colombia 2Swiss Swiss Federal Institute of Technology –EPFL, Laussane, Switzerland 3Andes University-GEST, Bogota, Colombia 4Montena EMC, Rossens, Switzerland
04P-30 Modeling Fluid/Structual Interaction in a Pulsed Power Accelerator J. A. Lips 1655 Pulsed Power Engineering, Sandia National Labs, Albuquerque, NM, United States
04P-31 Cygnus Source Emission D. S. Nelson1, E. C. Ormond1, M. E. Burke1, S. R. Cordova2, I. Molina2, E. A. Rose3, M. J. Berninger4, R. E. Gignac4, D. E. Good4, M. D. Hansen4, D. J. Henderson4, S. S. Lutz4, C. V. Mitton4
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1Sandia National Laboratories, Mercury, NV, United States 2Sandia National Laboratories, Albuquerque, NM, United States 3Los Alamos National Laboratory, Los Alamos, NM, United States 4National Security Technologies, North Las Vegas, NV, United States
04P-32 Microwave Shielding Measurement Method L. L. Hatfield, B. Schilder Electrical Engineering, Texas Tech University, Center for Pulsed Power and Power Electronics, Lubbock, United States
04P-33 Electro-Dynamic Force Analysis of Armature-Rail Tight Contact M. T. Li1, 2, P. Yan1, W. Q. Yuan1, Y. Zhou1, 2, 3, J. Wang1 1Institute of Electrical Engineering, Chinese Academy of Sciences, BeiJing, China 2Graduate University, Chinese Academy of Sciences, BeiJing, China 3School of Automation and Electrical Engineering, Tianjin University of Technology and Education, TianJin, China
04P-34 Current Distribution and Inductance Gradient Calculation at Different Rail Geometric Parameters Y. Zhou1, 2, 3, P. Yan1, W. Q. Yuan1, J. Wang1, M. T. Li1, 2 1Institute of Electrical Engineering, Chinese Academy of Sciences, BeiJing, China 2Graduate School, Chinese Academy of Sciences, BeiJing, China 3School of Automation and Electrical Engineering, Tianjin University of Technology and Education, TianJin, China
04P-35 Electro-Thermal-Mechanical Validation Experiments L. K. Tully, J. M. Solberg, D. A. White, D. A. Goerz, J. S. Christensen, T. J. Ferriera, R. D. Speer Lawrence Livermore National Laboratory, Livermore, United States
04P-36 A Simple Model of High-Power Thyristor and Its Application in EML Transient Analysis Y. Zhou1, 2, 3, P. Yan1, W. Q. Yuan1, J. Wang1, M. T. Li1, 2
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1Institute of Electrical Engineering, Chinese Academy of Sciences, BeiJing, China 2Graduate School, Chinese Academy of Sciences, BeiJing, China 3School of Automation and Electrical Engineering, Tianjin University of Technology and Education, TianJin, China
04P-37 Development of Gas-Discharge Lasers Using TPI-Type Pseudospark Switches P. A. Bokhan1, D. E. Zakrevsky1, M. A. Lavrukhin1, D. S. Churkin2, A. M. Razhev2, A. A. Zhupikov2, S. K. Vartapetov3, O. V. Gryaznov3, V. D. Bochkov4, D. V. Bochkov4, V. M. Dyagilev4, V. G. Ushich4 1Institute of Semiconductor Physics SB RAS, Novosibirsk, Russian Federation 2Institute of Laser Physics SB RAS, Novosibirsk, Russian Federation 3Physics Instrumentation Center at GPI RAS, Troitsk, Moscow region, Russian Federation 4Pulsed Technologies Ltd., Ryazan, Russian Federation
04P-38 Design and Analysis of Linear Flux-Switching Permanent Magnet Motor for Electromagnetic Launcher M. Mirzaei1, S. E. Abdollahi2 1Electrical Engineering, Amirkabir University of Technology, Tehran, Iran 2Electrical Engineering, University of Tehran, Tehran, Iran
04P-39 Compact 200-Hz Pulse Repetition GW Marx Generator System C. Nunnally, J. R. Mayes, C. W. Hatfield, M. B. Lara, T. R. Smith Applied Physical Electronics LC, Austin, TX, United States
04P-40 Development of a Solid State Versatile Pulsar for High Voltage and High Power Applications R. Varma, K. S. Sangwan Industrial Electronics Group, Central Electronics Engineering Research Institute (CEERI)/ Council of Scientific and Industrial Res, Pilani, Rajasthan, India
04P-41 Efficient Pulsed Power Generation A. Rahman, M. S. Alam, M. Y. El-Sharkh, N. Sisworahardjo, P. C. Byrne
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Department of Electrical and Computer Engineering, University of South Alabama, Mobile, AL 36688, United States
04P-42 Circuit Simulation Analysis of a Vircator Powered by Different High-Voltage Pulse Sources P. Appelgren, M. Akyuz, M. Elfsberg, T. Hurtig, C. Moeller, A. Larsson, S. E. Nyholm Swedish Defense Research Agency FOI, Tumba, Sweden
04P-43 Inductive Energy Storage Modulator Using SI Thyristor J. Li, M. Watanabe, E. Hotta Dept. of Energy Sciences, Tokyo Institute of Technology, Yokohama City, Japan
04P-44 Modeling of a Streamer Plasma Reactor Energized by a Capacitive Energy Pulse Modulator M. Wolf1, Y. Yankelevich1, A. Pokryvailo1, R. Baksht1, S. Singer2 1Soreq NRC, Yavne, Israel 2Tel-Aviv University, Tel-Aviv, Israel
04P-45 Design and Analysis of a Modified Homopolar Pulsed Generator M. Mirzaei1, S. E. Abdollahi2 1Electrical Engineering Department, Amirkabir University of Technology, Tehran, Iran 2Electrical Engineering Department, University of Tehran, Tehran, Iran
04P-46 A Semiconductor Switch and Magnetic Switch Based Multi Purpose Pulsed Power Generator G. H. Rim, J. S. Kim, H. J. Ryoo, Y. S. Jin, J. H. Cho, Y. B. Kim Industry Applications Research Division, KERI, Changwon, South Korea
04P-47 A Klystron Power System for the ISIS Front End Test Stand M. Kempkes1, K. Schrock1, A. Letchford1, 2, R. C. Ciprian1, T. Hawkey1, M. P. J. Gaudreau1 1Diversified Technologies, Inc., Bedford, MA, United States 2STFC Rutherford Appleton Laboratory, Didcot, United Kingdom
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04P-48 Commissioning of the 50 TW Leopard Laser Pulsed Power System B. Le Galloudec, S. Samek, B. McDaniel, V. Nalajala University of Nevada, Reno, Nevada, United States
04P-49 Optically Monitoring of the Marx Switches to Characterize AWE's Flash X-ray Machines S. G. Clough Pulsed Power Science and Engineering Group/DRAS, AWE, Reading, Berkshire, United Kingdom
04P-50 6-MV Vacuum Voltmeter Development B. V. Weber1, R. J. Allen1, R. J. Commisso1, D. D. Hinshelwood1, D. G. Phipps1, S. B. Swanekamp2 1Plasma Physics Division, Naval Research Laboratory, Washington, DC, United States 2L-3 Communications, Reston, VA, United States
04P-51 Design and Test of a Fast Capacitive High Voltage Probe H. Heo1, S. H. Kim1, S. S. Park1, S. H. Nam2, J. W. Shin2, D. W. Choi2, J. H. So2 1Pohang Accelerator Laboratory, Pohang, Kyungbuk, South Korea 2ADD, Daejeon, South Korea
04P-52 Electromagnetic Dot Sensor A. Al Agry, R. A. Schill, Jr., S. Garner, S. Andersen, K. Buchanan UNLV, Las Vegas, Nevada, United States
04P-53 High Speed (30ps) Transmission Line Current Sensor J. E. Barth Barth Electronics, Inc., Boulder City, NV, United States
04P-54 Advances in Fiber Based Faraday Rotation Current Measurements* A. D. White, G. B. McHale, D. A. Goerz Lawrence Livermore National Laboratory, Livermore, CA, United States
04P-55 Frequency-Domain Characterization of Pulsed Power Diagnostics* A. D. White, R. A. Anderson, D. A. Goerz Lawrence Livermore National Laboratory, Livermore, CA, United States
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04P-56 Compact Soft X-Ray Pulse Radiograph Based on X-Pinch and Low Scale Fast Capacitor Bank S. Chaikovsky, A. Rousskikh, N. Labetskaya, A. Fedunin, V. Feduschak, V. Oreshkin, N. Ratakhin, N. Zharova Institute of High Current Electronics, Tomsk, Russian Federation
04P-57 X-Ray Methodics for Local Time-Resolved Diagnostics of Relatively Small Concentrations of Metal in a High-Absorption Mediums for Definition of Concentration of Metal Vapors in a High-Current Pulsed Discharge P. G. Rutberg1, M. E. Pinchuk1, A. A. Bogomaz1, L. A. Shirochin2, M. A. Polyakov2, A. V. Budin1, S. Y. Losev1 1Institute for Electrophysics and Electric Power of Russian Academy of Sciences, St.-Petersburg, Russian Federation 2Sant-Petersburg State University of Telecommunications, St.-Petersburg, Russian Federation
04P-58 An Effective Way to Preserve X-Ray Film in the Explosive Experiment at the Diagnostic Test Bench B. T. Egorychev, A. V. Ivanovsky, A. I. Kraev, V. B. Kudelkin, V. V. Chernyshev RFNC-VNIIEF, Sarov, Nizhny Novgorod Region, Russian Federation
04P-59 Influence of Tube Volume on the Measurement Uncertainty of Geiger-Muller Counters K. Stankovic1, M. Vujisic2 1Institute of Nuclear Sciences "Vinca", Belgrade, Serbia 2Faculty of Electrical Engineering, University of Belgrade, Belgrade, Serbia
04P-60 Spectral Penning Ionization Gauge for Early Leak Detection in E-Beam Foils for Electra: 700 J, KrF Laser R. L. Jaynes1, J. L. Giuliani2, J. D. Sethian2, F. Hegeler3, A. E. Robson3, A. Magassarian1, M. F. Wolford2, P. M. Burns4 1Science Applications International, Corp., McLean, VA, USA 2Plasma Physics Division, Naval Research Laboratory, Washington, DC, USA 3Commonwealth Technology, Inc., Alexandria, VA, USA 4Research Support Instruments, Lanham, MD, USA
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04P-61 The High Performance Driver for Thyratron Tube C. Y. Liu Light Source Division/ Power Supply Group, National Synchrotron Radiation Research Center, Hsinchu, Taiwan
04P-62 Multiple Output Timing and Trigger Generator R. M. Wheat, G. E. Dale ISR Division, Group ISR-6, Los Alamos National Laboratory, Los Alamos, NM, United States
04P-63 Design and Testing of the High Voltage Capacitor Charger for 150kJ Pulsed Power Application H. J. Ryoo1, S. R. Jang2, J. S. Kim1, Y. B. Kim1 1Applied Electrophysic Research Center, KERI, Changwon, South Korea 2Dept of Energy Conversion Technology, University of Science & Technology, Daejeon, South Korea
04P-64 Repeatability Analysis in HV Capacitor Charging Applications A. Pokryvailo Spellman HV, Hauppauge NY 11788, United States
04P-65 A Fusing Switch for Fault Suppression in the SNS High Voltage Converter Modulators* M. A. Kemp1, C. Burkhart1, M. N. Nguyen1, D. E. Anderson2 1Power Conversion Department, SLAC National Accelerator Laboratory, Menlo Park, CA, United States 2Oak Ridge National Laboratory, Oak Ridge, TN, United States
04P-66 Optimal Design of a Two Winding Inductor Based Bouncer Circuit D. Bortis, J. Biela, J. W. Kolar ETH Zurich, Zurich, Switzerland
04P-67 Transient Behavior of Solid State Modulators with Split Core Transformer D. Bortis, J. Biela, J. W. Kolar Power Electronics Laboratory, ETH Zurich, Zurich, Switzerland
04P-68 A Vernier Regulator for ILC Marx Droop Compensation T. Tang, C. Burkhart, J. Olsen
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Power Conversion Department, Stanford Linear Accelerator Center, Menlo Park, United States
04P-69 Comparative Evaluation of Isolated Medium Voltage DC-DC Converter Topologies for Recharging the Energy Storage of Pulsed Power Systems G. I. Ortiz, D. Bortis, J. W. Kolar ETH Zurich, Zurich, Switzerland
04P-70 A 432-kW Peak Power Solid-State Resonant Link Power Modulator System* N. Schoeneberg, D. Szenasi, M. Coblentz, C. Lors, W. Drumheller, K. Jansen, C. Manzanares, V. Gorodetsky, R. Jolin, B. Childress, D. Barrett High Power Solutions Division, Science Application International Corporation, Manassas, VA/Albuquerque, N.M, United States
Thursday July 2 15:00 - 17:00 Colonial Oral Sessions Session Chair: Mike Kempkes
Diversified Technologies Inc. Session O21: Industrial, Commercial, & Medical Applications 021-1 Scalable, Compact, Nanosecond Pulse Generator with a High
Repetition Rate for Biomedical Applications Requiring Intense Electric Field J. M. Sanders, A. Kuthi, Y. H. Wu, P. T. Vernier, C. Jiang, M. A. Gundersen Electrical Engineering - Electrophysics, University of Southern California, Los Angeles, CA, United States
O21-2 Pulsed Power for a Dynamic Transmission Electron Microscope* W. J. DeHope, N. D. Browning, G. H. Campbell, E. G. Cook, W. E. King, T. B. LaGrange, B. J. Pyke, B. W. Reed, R. M. Shuttlesworth, B. C. Stuart Lawrence Livermore National Laboratory, Livermore, CA, United States
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O21-3 High Power UV and VUV Excilamps and Their Applications V. F. Tarasenko, S. M. Avdeev, M. V. Erofeev, M. I. Lomaev, E. A. Sosnin, V. S. Skakun, D. V. Shitz High Current Electronics Institute, Tomsk, Russian Federation
O21-4 ADRE-Plasma Processing of Solid State Surface A. N. Maltsev1, I. R. Arslanov2, S. N. Garagaty2, A. Y. Ivanov2, D. Y. Kolokolov2, I. N. Lapin2, V. V. Chupin2 1Institute of Atmospheric Optics Russian Academy of Sciences, Tomsk, Russian Federation 2Electrodinamic Systems & Technologies, LLC, Tomsk, Russian Federation
O21-5 Optimization of Reactor Dimensions for Air Pollution Control by Pulsed Power Discharges T. K. Sindhu, M. Manju, D. Kavitha, S. Selvakumar Electrical and Electronics Engineering, Amrita Vishwa Vidya Peetham, Coimbatore, Tamil Nadu, India
O21-6 A Compact Underwater Shock Wave Generator Using Magnetic Pulse Compression Circuit for Medical Applications S. Iwasaki, D. K. Kang, S. Nakamitsu, S. H. R. Hosseini, T. Sakugawa, H. Akiyama Graduate School of Science and Technology, Kumamoto University, Kumamoto, Japan
O21-7 Novel Atmospheric Pressure Non-Thermal Plasma Needle for Selective Killing of Melanoma Cell T. M. DiSanto, J. L. Zirnheld, B. Onyenucheya, K. M. Burke Energy Systems Institute, University at Buffalo, Buffalo, NY, United States
O21-8 An Ultra-Portable Marx Generator-Based Solution for MIL STD 461E/F RS-105 Testing J. R. Mayes, M. B. Lara, W. C. Nunnally, M. G. Mayes, J. Dowden Applied Physical Electronics, L.C., Austin, Texas, United States
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Thursday July 2 15:00 - 17:00 Ballroom Session Chair: Jacob Walker
Naval Surface Warfare Center Dahlgren Division Session O22: Bulk Optical Switches and Components O22-1 GaN and 6H-SiC Photoconductive Switches
J. S. Sullivan Lawrence Livermore National Laboratory, Livermore, CA, United States
O22-2 Solid-State High-Voltage Crowbar Utilizing Series-Connected Thyristors J. F. Tooker, P. Huynh, R. W. Street Fusion Energy Research, General Atomics, San Diego, CA, United States
O22-3 Pulsed and DC Charged PCSS Based Trigger Generators S. F. Glover1, F. J. Zutavern1, M. E. Swalby1, M. J. Cich1, G. Loubriel1, A. Mar1, F. E. White2 1Sandia National Laboratories, Albuquerque, NM, United States 2Ktech Corporation, Albuquerque, NM, United States
O22-4 GaAs PCSS for DC Charged Pulsed Power Applications F. J. Zutavern1, S. F. Glover1, M. E. Swalby1, A. Mar1, G. Loubriel1, L. D. Roose1, F. E. White2 1Sandia National Laboratories, Albuquerque, NM, United States 2Ktech Corporation, Albuquerque, NM, United States
O22-5 Optically Isolated Circuit for Failure Detection of a Switch in a HV Series Connected Stack V. Senaj, N. Voumard, M. J. Barnes, L. Ducimetiere TE/ABT/FPS, CERN, Geneva, Switzerland
O22-6 A Miniature High-Power POS Driven by a 300 kV Tesla Charged PFL Generator B. M. Novac, K. Rajesh, I. R. Smith, C. Greenwood Electronic and Electrical Engineering, Loughborough University, Loughborough, Leicestershire, United Kingdom
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O22-7 Reverse Matched Pulse Circuits with Minimum Loss J. E. Barth Barth Electronics, Inc., Boulder City, NV, United States
O22-8 Peculiar Photoconductivity in Nonlinear GaAs Photoconductive Semiconductor Switch J. Yuan1, X. Wang1, W. Jiang1, H. Liu2, J. Liu2, W. Xie2, H. Li2 1Department of Electrical Engineering, Tsinghua University, Beijing, China 2Institute of Fluid Physics, China Academy of Engineering Physics, Sichuan, China
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PPC-2009
THE 17TH IEEE INTERNATIONAL PULSED POWER
CONFERENCE
ABSTRACTS
Conference Record Abstracts
102
MONDAY
JUNE 29
O1: E-Beam Driven X-ray Sources
O2: Compact Pulsed Power
O3: Narrow Band and Electron Devices
O4: High Energy Density Plasmas – Z Pinches
O5: RF/HPM Systems and Effects
O6: Pulsed Power Sources – High Current Accelerators
O1: E-Beam Driven X-ray Sources Colonial
Monday, June 29 10:00-12:00
O1-1: Characterization of the Rod-Pinch Diode X-Ray Source on Cygnus
B. V. Oliver1, G. Cooperstein2, S. Cordova1, D. Crain3, D. W. Droemer3, Haines, T. 4, Hinshelwood, D. 2, N. King4, S. S. Lutz3,
C. L. Miller5, I. Molina1, D. Mosherr6, D. Nelson1, E. C. Ormond1, S. Portillo7, J. Smith4, D. R.
Welch5, W. M. Wood4
1Sandia National Laboratories, Albuquerque, NM, United States
2Naval Research Laboratory, Washington, DC, United States
3National Securities Technologies, LLC, Las Vegas, NV, United States
4Los Alamos National Laboratories, Los Alamos, NM, United States
5Voss Scientific, LLC, Albuquerque, NV, United States
6L-3 Pulse Sciences, San Leandro, CA, United States
7Ktech Corp., Albuquerque, NM, United States
The rod-pinch diode [1] is a self-magnetically insulated electron beam diode that is capable of producing a very bright source of hard x-rays. As fielded on the Cygnus accelerators [2], the diode operates at an impedance of 50 Ohms and produces short pulse (~50 ns) bremsstrahlung radiation with a 2.2 MeV photon endpoint energy and dose of 4 rad measured at one meter, with x-ray spot size ~ 1mm. Recently, a series of experiments on Cygnus have been conducted to better characterize the diode’s operation and x-ray output. In particular, the x-ray spectral content, source size, and shot-to-shot reproducibility have been diagnosed. The intent of these experiments is to enable improvements that may extend the diode’s radiographic utility. An array of end-on and side-on viewing x-ray diagnostics have been utilized which include, pin hole imaging, time resolved and time integrated spot size measurements, step wedges, as well as diode current and voltage measurements. High fidelity, PIC/Monte-Carlo simulations have also been conducted to help analyze the data. An overview of these experiments and simulations, the conclusions from analysis and a discussion of future plans is presented. [1] R. A. Mahaffey, J. Golden, S. A. Goldstein, and G. Cooperstein, Appl. Phys. Lett. 33, 795 (1978) [2] D. Weidenheimer, P. Corcoran, R. Altes et al., in Proc. 13th IEEE Int. Pulsed Power Conf., 2001, pp. 591-595
O1-2: Cygnus Dose Symmetry* E. C. Ormond1, D. Nelson1, S. Cordova2,
I. Molina2, J. R. Smith3, E. A. Rose3, R. E. Gignac4, D. E. Good4, M. D. Hansen4, D. J. Henderson4, C. V. Mitton4, S. S. Lutz4
11649-1, Sandia National Laboratories, Mercury, NV, United States
21645, Sandia National Laboratories, Albuquerque, NM, United States
3Los Alamos National Laboratory, Los Alamos, NM, United States
4National Security Technologies, Las Vegas, NV, United States
The Cygnus Dual Beam Radiographic Facility consists of two identical radiographic sources each with a dose rating of 4-rad at 1 m, and a 1-mm diameter spot size. The development of the rod pinch diode was responsible for the ability to meet these criteria. The rod pinch diode in a Cygnus machine uses a 0.75-mm tungsten diameter tapered anode rod extended through a 9-mm diameter cathode aperture. When properly configured, the electron beam born off the aperture edge can self-insulate and pinch onto the tip of the rod creating an intense, small x-ray source. The Cygnus sources are utilized as the primary diagnostic on experiments, which are single-shot, high-value events. In such an application there is an emphasis on reliability and reproducibility. The azimuthal quality and reproducibility of the Cygnus source will be analyzed using lithium fluoride thermoluminescent dosimeters. Photogrammetry will be used to quantify the precision of the rod pinch diode build (i.e. the centeredness the anode rod). One goal of these tests will be investigation of the relationship of dose symmetry to anode rod position (i.e. the correlation of off-center dose to an off-center anode rod). * Work supported by Sandia National Laboratories. Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under Contract DE-AC04-94-AL85000.
O1-3: Detailed Simulation of the CYGNUS Rod Pinch Radiographic Source C. L. Miller1, D. R. Welch1, D. V. Rose1,
B. V. Oliver2 1Voss Scientific, LLC, Albuquerque, NM, USA
2Sandia National Laboratories, Albuquerque, NM, USA
In this paper, we present results from LSP simulations of the nominally 2-MV, 40-kA CYGNUS radiographic machine[1] using a standard rod pinch diode.[2] The rod pinch electron beam diode consists of a small diameter, high atomic number anode extending through a thin cathode aperture. Typically, the beam electrons have stopping ranges larger than the anode diameter and must undergo multiple passes through the rod producing bremsstrahlung radiation in the process. The evolution of rod pinch begins with the space charge limited electron emission phase and, after anode heating and plasma formation enters the pinched phase. At this time, electrons stop striking the anode rod directly and cycle around the rod to strike the tip. Significant shot-to-shot variation of the photon spectrum can introduce an error in interpreting the radiograph. To model these effects, we use the LSP code [3,4] which includes detailed, time-accurate modeling of the electrons within the dense anode with the ITS (Integrated Tiger Series) Monte Carlo package.[5,6] Our preliminary results suggest the incident electrons trajectories show only incremental variation with varying applied voltages, with most of them striking the anode within 3 mm of the rod tip. This consistency applied to the resultant X-ray spectrum as well, with changes only to the value for the end-point energy. Allowing stimulated electron emission from the cathode due to anode ion impact leads to a large radius for electron production, but enhances current directly back to the anode base by only a few percent. We will present results from these integrated simulations of electron and photon generation and quantify the sensitivities on the photon distribution and compare these to measured data. 1. J. R. Smith, et al., “Performance of the Cygnus X-ray Source,” Beams 2002: 14th International Conference on High-Power Particle Beams, Albuquerque, New Mexico, June 23–28, 2002. 650, 135–8. 2. R. A. Mahaffey, J. Golden, S. A. Goldstein, and G. Cooperstein, Appl. Phys. Lett. 33, 795 (1978). 3. T. P. Hughes, S. S. Yu, and R. E. Clark, Phys. Rev. 2, 11041 (1999). 4. D. R. Welch, D. V. Rose, B. V. Oliver, and R. E. Clark, Nucl. Instrum. Methods Phys. Res. A 464, 134 (2001). 5. J. A. Halbleib, R. P. Kensek, G. D. Valdez, S. M. Seltzer, and M. J. Berger, IEEE Trans. Nucl. Sci. 39, 1025 (1994). 6. D. V. Rose, D. R. Welch, B. V. Oliver, R. E. Clark, D. L. Johnson, J. E. Maenchen, P. R. Menge, C. L.
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Olson and D. C. Rovang, J. Appl. Phys. 91, 3328 (2002). *Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.
O1-4: X-Ray Absorption and Scattering Issues for Rod-Pinch Radiographic
Sources* D. Mosher1, D. Hinshelwood2, G. Cooperstein2,
B. M. Huhman2, R. J. Allen2, S. S. Lutz3, M. J. Berninger3, B. V. Oliver4, S. Portillo5,
T. Haines6 1L-3 Communications, Reston, VA, United States
2Naval Research Laboratory, Washington, DC, United States
3National Security Technologies, North Las Vegas, NV, United States
4Sandia National Laboratories, Albuquerque, NM, United States
5Ktech Corporation, Albuquerque, NM, United States
6Los Alamos National Laboratory, Los Alamos, NM, United States
During the past decade, the megavolt pulsed-power-driven rod-pinch source has been used extensively for high-brightness x-ray radiography [1, 2]. For this application, a mm-diameter tungsten rod anode extends through a washer-shaped cathode, and magnetic forces drive the electron beam emitted from the cathode to a pinch onto the tapered rod tip. Bremsstrahlung radiation from the tip irradiates extended objects meters distant from the source on the rod axis of symmetry. For the present work, two measures of radiographic performance are of interest: radiographic spot size and uniformity of irradiation across the object plane. The spot size may be larger than that associated with the rod geometry because of hydrodynamic expansion due to electron-beam heating. Here, we investigate possible increase in spot size by another mechanism: forward scattering by the large-diameter cathode of x-rays from the nearby rod tip. This scattering is observed in side-viewing pinhole images which show x-rays emanating from the cathode. Also observed and studied here is a radial nonuniformity in the object plane due to differential x-ray attenuation by the rod tip as a function of angle from the axis of symmetry. Measurements in a non-pinched, tapered-rod configuration show that the degree of nonuniformity is well-correlated with the axial extent of electron-beam deposition on the rod. X-ray imaging data from Cygnus [2] and HRS [3] are analyzed by, and correlated with, the ITS Monte-Carlo codes [4] to determine if the two phenomena considered here can impact radiographic performance. *Work supported through Sandia National Laboratories, a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000. 1. G. Cooperstein, J.R. Boller, R.J. Commisso,
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D.D. Hinshelwood, D. Mosher, P.F. Ottinger, J.W. Schumer, S.J. Stephanakis, S.B. Swanekamp, B.V. Weber, and F.C. Young, "Theoretical Modeling and Experimental Characterization of a Rod-Pinch Diode," Phys. Plasmas 8, 4618 (2001). 2. B.V. Oliver, these Proceedings. 3. R.J. Allen, G. Cooperstein, F.C. Young, J.W. Schumer, D.D. Hinshelwood, D. Mosher, D. Holmberg, and S.E. Mitchell, “Characterization and Optimization of a Compact 1-MV, 6-kA Radiographic Source,” Proc. 14th IEEE International Pulsed Power Conf., (Dallas, TX, June 2003), p. 883. 4. J.A. Halbleib, R.P. Kensek, G.D. Valdez, S.M. Seltzer, and M.J. Berger, “ITS: The Integrated TIGER Series of electron/photon transport codes-Version 3.0”, IEEE Trans. Nucl. Sci. 39, 1025 (1992).
O1-5: Status of Self-Magnetic Pinch Diode Investigations on RITS-6*
K. Hahn1, B. V. Oliver1, S. Cordova1, J. J. Leckbee1, I. Molina1, M. D. Johnston1,
T. J.Webb1, N. Bruner2, D. V. Rose2, D. R. Welch2, S. Portillo3, D. Ziska3, S. Clough4,
A. Critchley4, I. Crotch4, A. Heathcote4, A. Jones4, J. Threadgold4
1Sandia National Labs, Albuquerque, NM, United States
2Voss Scientific, Albuquerque, NM, United States 3KTech Corporation, Albuquerque, NM, United
States 4Atomic Weapons Establishment, Reading,
Berkshire, United Kingdom The electron beam-driven self-magnetic pinch diode is presently fielded on the RITS-6 accelerator at Sandia National Laboratories and is the leading candidate for future x-ray radiographic source development at the Atomic Weapons Establishment. The diode is capable of producing sub 3-mm radiation spot sizes and greater than 350 Rads measured at 1 m from the x-ray source. While RITS-6 is capable of delivering 12 MV using a magnetically insulated transmission line (MITL), the diode typically operates between 6 - 7 MV, thereby limiting the power-law scaling of dose production with voltage. Coupling this low-impedance diode to a MITL with similar or higher impedance affects its radiographic potential. The diode operational sensitivity is compounded by complex physical processes. In particular, the interaction of evolving plasmas from the cathode and anode seem to limit the diode stability to a narrow operating regime. To better quantify the diode physics, high-resolution, time-resolved diagnostics have been utilized which include plasma spectroscopy, gated imaging, x-ray p-i-n diodes, spot size, and diode/MITL current measurements. The data from all of these diagnostics are also used to benchmark particle-in-cell simulations in order to better understand the underlying physics of operation and diode coupling to a MITL. An overview of these experiments and simulations including future plans is presented. * Work supported by Department of Energy’s National Nuclear Security Administration under Contract DE-AC04-94-AL85000.
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O1-6: Plasma Dynamics in Relativistic Electron Beam Diodes for Flash X-Ray
Radiography M. D. Johnston1, B. V. Oliver1, S. Portillo1,
D. R. Welch2, D. W. Droemer3 1Sandia National Laboratories, Albuquerque, NM,
United States 2Voss Scientific, LLC, Albuquerque, NM, United
States 3National Security Technologies, LLC, Las
Vegas, NV, United States
Experiments have been conducted at Sandia National Laboratories’ RITS-6 accelerator facility (operating at 7.5 MV and 180 kA) investigating plasma formation and propagation in relativistic electron beam diodes used for flash x-ray radiography. High resolution, visible and ultraviolet spectra were collected in the A-K gap of the Self-Magnetic Pinch (SMP) diode. Time and space resolved spectra are compared with time-dependent, collisional-radiative (CR) calculations and Lsp, hybrid particle-in-cell code simulations. Results indicate the presence of a dense (1x10^17 cm-3), low temperature (few eV), on-axis plasma, composed primarily of protons from electrode surface contaminants, which rapidly expands (10-30 cm/us) from the anode to the cathode. In addition, a cathode plasma sheath is observed which extends several millimeters into the A-K gap. It is believed that the interaction of these electrode plasmas causes a premature impedance collapse of the diode and subsequent reduction in radiation output. Diagnostics include high speed imaging and spectroscopy using nanosecond gated ICCD cameras, streak cameras, and photodiode arrays.
O1-7: Comparisons of the Self Pinch Diode and Paraxial Diode Electron
Distributions at the Conversion Target Using LSP
P. N. Martin, S. Vickers AWE, Aldermaston, United Kingdom
Simulations of radiographic diodes are routinely used at AWE to investigate the operation of x-ray sources used to radiograph heavy metal driven implosion experiments. The x-ray generation is heavily dependant on the distribution of electrons striking the Bremstrahlung conversion target and being able to accurately describe this distribution is key to any given simulation being useful. The time resolved distribution of electrons striking the Bremstrahlung conversion target for both the self magnetic pinch diode [1] and paraxial diode [1] are described using the LSP PiC code [2] and compared both to each other and to the common first approximations of a shell of electrons and fully filled cone respectively. [1] T. J. Goldsack et al., “Multi-megavolt multi-axis high resolution flash X-ray source development for a new hydrodynamics research facility at AWE, Aldermaston,” IEEE Trans. Plasma Sci., vol. 30, no. 1, pp. 239-253, Feb 2002. [2] LSP is a software product of ATK-Mission Research Corp. www.mrcabq.com.
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O2: Compact Pulsed Power Ballroom
Monday, June 29 10:00-12:00
O2-1: Study of Hybrid Nonlinear Transmission Lines for High Power RF
Generation J. Rossi, P. N. Rizzo
Associated Plasma Laboratory, National Institute for Space Research -INPE, S.J. Campos, SP,
Brazil Nowadays there has been a great interest in the study of nonlinear transmission lines (NLTLs) for high power RF generation. This has been motivated by two scientific advances. The first one obtained recently by Seddon et al. [1] was the development of a saturated ferrite core TL that is capable of generating RF power peaks of about 20 MW with efficiency of 20 % at 1.0 GHz. The other one was the experimental work developed by Smith [2] at Oxford involving NLTLs made of barium or strontium titanate ceramic tiles, which provided 60 MW RF power at frequencies between 100 - 300 MHz. Later, they argued it would be possible to produce solitons with higher frequencies (particularly for the SrTiO3 line) since in their experiment the measurements were compromised by the limited bandwidth of the electrical diagnostics used (around 200 MHz). However, another possibility arisen in [2] is that the nonlinearity of the ceramic materials used as dielectrics was not sufficiently large since soliton frequencies obtained were much less than the relaxation frequency f of the nonlinear materials employed (f > 1 GHz for strontium titanate). Then, a possible approach to reach higher frequencies for the Oxford line would be the additional use of ferrite blocks laid between the barium strontium titanate tiles as the ferrite permeability drop will produce an additional increase on the soliton frequency. This proposed line is called hybrid line and to-date there is no report about such line being tested to our knowledge. As a result, the main point of this paper is to study a hybrid line made of discrete nonlinear components Ls & Cs using a SPICE simulator. For this, we use a program called LT_SPICE in which the inductor L with a saturated magnetic core is of easy implementation. For the nonlinear capacitors, varactors diodes are used to produce the C-V dependence as these devices have been used with great success to build and simulate NLTLs for soliton generation in the MHz range. Herein an important aspect consists of investigating the RF extraction at a load matched to the line output as hybrid lines allow their characteristic impedance Z to be kept constant along the line length. Some simulation results and comparison with experimental measurements for a hybrid line prototype operating at low voltages will be provided. It is expected that these results could also serve as an important tool for future designs
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of compact hybrid NLTL systems for operation at higher frequencies (1.0 - 2.0 GHz) in mobile platforms of defense systems or satellite communications, especially if ferroelectric capacitors are used as nonlinear elements for high power operation. [1] N. Seddon, C.R. Spikings, & J.E. Dolan, RF Pulse Formation in NLTLs, in Proc. of the 2007 Pulsed Power Conf., pp. 678-681. [2] J. A. Gaudet, E. Schamiloglu, J.O. Rossi, C.J. Buchenauer, & C. Frost, Non-Linear Transmission Lines For HPM Applications - A Survey, in Proc. of the 2008 IEEE Power Modulators & HV Conf., pp. 131-138.
O2-2: A 250kV-300ps-350Hz Marx Generator as Source for a UWB Radiation
System L. Pecastaing1, B. Cadilhon1, T. Reess1,
A. De Ferron1, P. Pignolet1, S. Vauchamp2, J. Andrieu2, M. Lalande2, J.P. Brasile3
1Laboratoire de Genie Electrique - UPPA, Pau, France
2XLIM OSA, Brive, France 3Thales Communisations, Colombes, France
The paper aims at presenting the design and realisation of an autonomous, ultra wideband (UWB) radiation source consisting of a high gain broadband antenna driven by a subnanosecond pulsed power source. The high voltage pulse source is a single ten stage subnanosecond Marx generator which delivers pulses in the range of 250kV/1.5J, with a minimum 300ps rise-time, subnanosecond pulse duration at a maximum pulse repetition frequency of 350Hz. The main particularity of our system is to integrate the pulse forming device (a peaking stage and a crowbar switch), directly on the last stage of the Marx generator. This adjustment avoids the loss of output pulse amplitude due to a classical pulse forming line. The development of the Marx generator combined with its own pulse forming device is explained and discussed in the paper. Dedicated home made probes based on capacitive line divider are realized to measure both the temporal characteristics and the high voltage amplitude of the pulses delivered by the pulsed power source. These probes allow to observe voltage pulses without perturbation in any place of the circuit and to measure their main characteristics. Its 2.3GHz high cut off frequency and its sufficient division ratio permits to measure the rise-time, fall-time, pulse width and the amplitude of the output signal of the pulser. Calibration tests in the frequency and time domain are also performed and detailed in the paper. Another major factor in UWB radiation systems is the radiating element. The pulsed source is combined with a travelling wave antenna called Valentine antenna. Some mechanical modifications were made to improve the dielectric strength of this radiating element. A 3-D model of its structure, on a time domain electromagnetic software, was first performed to study the influence of these modifications on the main radiating characteristics of the antenna. Then, this antenna is tested with HV pulses in order to avoid any undesirable breakdown. Various tests on the whole source (battery-DC/DC converter-Marx generator-pulse forming device-antenna) were investigated in order to evaluate the figure-of-merit of our system. A novel method to measure high level electromagnetic fields, called MICHELSON method, is used. The incident field scattering on
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a target permits to move the field measurement toward a novel location, where a simple equipment can measure the scattered field without breakdown risk. The results obtained with this method are compared to ones measured with a classical derivative field sensor. Moreover, the high gain and capability of the Valentine antenna to radiate short pulses without dispersion allow to achieve a high measured figure-of-merit. Finally in this paper, the maximum figure-of-merit obtained is 450kV with our compact source.
O2-3: Development of Miniature Marx Generator Using BJT
M. Inokuchi1, T. Ueno2, M. Akiyama1, T. Sakugawa1, H. Akiyama1
1Graduate School of Science and Technology Kumamoto University, Kumamoto, Japan
2Oita National College of Technology, Oita, Japan
We have studied and developed a small sized all solid-state pulsed power generator for industrial applications and biomedical applications such as an ozonizer and a cell treatment. In this paper, we describe a novel 19 stages miniature Marx generator using bipolar junction transistors (BJTs) to produce high voltage and low energy pulses with nano-seconds pulse rise time. This pulsed power generator consists of a Cockroft-Walton circuit and a Marx circuit. The Cockroft-Walton circuit is able to charge all capacitors and the charging voltage is about 300 V. The Marx circuit consists of resistors, capacitors, and BJTs as extreme high speed closing switches by avalanche breakdown phenomena. And the size of Marx circuit is 72 mm x 95 mm. The effect utilized to achieve rise-time of nano-seconds or faster is the avalanche breakdown of BJTs. The short-pulsed power generator has an output voltage of about -4.5 kV and pulse duration of 5 nano-seconds by series BJTs for cutting load current. And the charging energy is milli-Joule regime. At these points, we recommend using for biomedical applications.
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O2-4: 0.5MJ 18kV Module of Capacitive Energy Storage
B. E. Fridman, R. S. Enikeev, N. A. Kovrizhnykh, K. M. Lobanov, R. A. Serebrov
STC "SINTEZ", D.V. Efremov Scientific Research Institute of Electrophysical Apparatus, St.-
Petersburg, Russian Federation
The module of the capacitive energy storage is intended to investigate high-current electrical discharges in dense media. The module is a functionally completed remote-operated capacitive energy storage built on eight capacitor cells with semiconducting switches [1]. The module comprises a charger with a high-frequency inverter, a protection contactor with normally closed high-voltage contacts to neutralize cell charge, control units of RSD switches, control and diagnostics apparatus with a programmable logic controller. The semiconducting switches in the capacitor cells are triggered by light pulses transmitted from a remote control board via eight optical cables. Information exchange between the module control and diagnostics system and the remote terminal is also realized via optical cables. The storage is designed for operation in the programmable discharge mode, when semiconducting switches in the capacitor cells are switched on in the specified time sequence according to the preset program. A maximal current pulse amplitude of 400 kA at the module output is attained during simultaneous discharge of all eight cells in the short-circuit mode. The wave-front of the current pulse is 150 mcs. The volume of the capacitor module is 1.3 m3. 1. B.E. Fridman, et al., Energy Storage Capacitor Cell with Semiconductor Switches. In Proc. 2007 IEEE Pulsed Power Conf., p. 542 545.
O2-5: Development of a Compact Xpinch Driver with Single Cap-Single Switch
Design. First Results for Radiography of Wire Array Experiments within Sphinx
Project A. Loyen, F. Lassalle, P. Maury, A. Morell,
H. Calamy, P. Combes, A. Georges EXN/MAN, Centre d'ETudes de Gramat,
GRAMAT, France
A compact X-pinch driver has been developed within the Sphinx project for radiography of wire array loads. For cost reduction, it uses components of same technology as Sphinx machine : a single 1.3 µF, 90kV capacitor and a single multigap-multichannel (MMCS) switch. Its dimensions are 0.4m*0.4m*1m. At 70kV charging voltage, it delivers on a ~ 10 nH inductive load a current of 250 kA with a 290 ns rise time (10-90% of Imax).In order to be integrated into the Sphinx vacuum chamber for future experiments, the vacuum transmission line is highly constrained; this line has a 48mm external diameter, a 3mm gap and a 405mm length and represents a fifth of the total inductance of the generator. Details are given on the architecture and performances of the X-pinch driver. First results with X-pinch loads made of 2 and 4 wires as well as plans for radiography of wire array experiments are described. _______________________________ * Work supported by French Ministry of Defense – DGA/DUM NBC
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O2-6: Development of 150kJ Compact Pulsed Power System for ETC
Accelerator B. H. Lee, J. S. Kim, S. H. Kim, K. S. Yang
The 4th R&D Institute-1, ADD, Daejeon, South Korea
This paper describes a 150kJ compact pulsed power system(CPPS) for electrothermal chemical(ETC) accelerator on a vehicle. The CPPS provides pulsed electrical energy into plasma injector which generates tens of thousands K plasma and has the characteristics of nonlinear resistance depending on the current. The design requirements of the CPPS are as follows: the maximum power of 200 MW, the pulse width of about 500 μs, the volume of no more than 0.5 , the efficiency of energy transfer over 80 %, the repetition rate of 4~5 times per minute. The 150kJ CPPS is composed of four 37.5kJ capacitor bank modules in parallel to make a rectangular pulse shape and satisfy the above requirements. Each module is designed and fabricated to achieve a high reliability, safety, efficiency and density considering several expected conditions of worst operation. The test result of the 150kJ CPPS in the conditions of normal and worst operation is presented.
O2-7: Nano- and Picosecond Pulse Generators Based on FID Technology V. M. Efanov, M. V. Efanov, A. V. Kriklenko, P. M. Yarin, A. V. Komashko, A. A. Arbuzov
FID GmbH, Burbach, Germany
Several families of high voltage pulse generators with amplitude from several kilovolts to hundreds of kilovolts and pulse duration from 0.1 ns to 10 ns have been developed. High voltage pulse generators can have output voltage with amplitude of 15-20 kV into 50 Ohms, rise time of 100 ps, and pulse duration of 200-300 ps with pulse repetition frequency of up to 100 kHz. At amplitudes of 1-2 kV possible, PRF is up to 5 MHz. One of the groups of generators delivers ultra-short pulses: rise time of 20-30 ps, amplitude of up to 10 kV and pulse duration of about 100 ps. For accelerator and laser applications, new pulsers with rectangular pulse shape have been developed. These pulsers provide output amplitude of up to 100 kV and pulse duration of 2-20 ns. Rise time can be tailored from 100 ps to several nanoseconds. There are now units with continuous adjustment of pulse duration in the range from several nanoseconds to several microseconds at an amplitude of up to 20 kV. All pulsers feature high amplitude stability, with typical jitter of less than 30 ps. It is possible to simultaneously operate a large number of these pulsers into a single load with an accuracy of tens of picoseconds. The most compact pulse generators of this group have a peak power of up to hundreds of megawatts with dimensions of about 200x100x50 mm.
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O2-8: High-Power, Compact and Repetitive Driver for Pulsed Electron
Beam Generation R. Shukla, P. Deb, S. K. Sharma, A. Shyam,
P. Banerjee, T. Prabahar, B. Adhikary, K. G. Shah
E&ED, BARC, Mumbai, India
In this paper we are presenting the design, fabrication and operation details of compact air core pulse transformer which is used for Pulsed High Voltage Charging of Pulse forming line or fast capacitor for driving an electron beam source. The Transformer output voltage is fed to different pulse forming lines varying in capacitance and dielectrics like water, ethelene glycol and solid dielectric. The measured peak output voltage is 130kV for 1.1 nanofarad capacitance Pulse forming line made by polythelene solid-dielectric. This output voltage is generated from only 3kV charged 4uF capacitor connected in primary of pulse transformer which discharges through a spark gap. The connections of capacitor to the primary of coil is made low-inductive to give maximum flux coupling and efficiency. The energy efficiency of system is ~70% which is very good for proposed energy efficient repetitive operation. The voltage limits of operation of this tranformer are also reported in this paper. The whole primary circuit system with transformer is 1 feet in length 1 feet width and 0.5 feet height which makes it compact. The use of air core makes the transformer very low weight system which is not exceeding 2 kgs. The study of operation of this pulse transformer with various pulse forming lines and optimization of this transformer for highest possible output voltages is theme of this paper. This pulse transformer, when connected with optimized pulse forming line, generates electron beams of very high power which can be used for various applications. The demonstration of electron beam generation from this compact system is also presented in the paper.
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O3: Narrow Band and Electron Devices
Ballroom
Monday, June 29 13:00-14:30
O3-1: Generation of Sub-GW-Level RF Pulses in Nonlinear Transmission Lines
V. V. Rostov, N. M. Bykov, D. N. Bykov, A. V. Gunin, A. I. Klimov, V. O. Kutenkov,
I. V. Romanchenko High Current Electronics Institute, Tomsk,
Russian Federation Many researchers are focusing on Nonlinear Transmission Lines (NLTLs) to produce high power RF pulse oscillators [1-4]. The key components in such devices are the nonlinear materials which are used to provide the direct energy conversion of high voltage pulse in to electromagnetic oscillations. This paper presents the new experimental results obtained using two types of NLTLs. Authors used two nonlinear elements in a high voltage coaxial line: (1) the periodical structure of gas gaps, and (2) the homogenous fill up with saturated ferrite under axial bias. The concept of the first one is due to the in-phase composition of RF fields excited by currents in periodical succession of gas gaps in the internal conductor. The most stable, narrow-band and efficient operation of system with 12 cylindrical gas gaps (200 kV, 18 ns) was realized at RF frequency of 1 GHz and RF power of few hundreds MW. The maximum power conversion efficiency was estimated as 10%. The bandwidth was amounted near 10 % at -3 db level. In the second NLTL there was no spatial dispersion. In this case the self-consistent traveling magnetic field dynamics in the course of coherent magnetic switching in ferrites under axial bias was observed. The pulse voltage driver formed 9 ns pulses from 110 to 290 kV. The reached efficiency of energy transformation for first 8 oscillations is about 10% at the optimal external magnetic field. The peak power in oscillations formed on a resistive load is estimated to be about 400 MW. The linear growth of central frequency from 600 MHz to 1.1 GHz with incident pulse amplitude was found. 1. A.M. Belyantsev, A.I. Dubnev, S.I Klimin, Yu.A. Kobelev and L.A. Ostrovskii Generation of radio pulses by an electromagnetic shock wave in a ferrite loaded transmission line, Tech. Phys. vol 40(8), pp 820-826, 1995. 2. M.P. Brown and P.W. Smith High power pulsed soliton generation at radio and microwave frequencies. Proc. of 11th IEEE Pulsed Power Conf., Baltimore, pp. 346-354, 1997. 3. N. Seddon, C.R. Spikings, and J.E. Dolan RF Pulse Formation in Nonlinear Transmission Lines, IEEE Pulsed Power & Plasma Science Conf., Albuquerque, pp. 678-681, 2007. 4. J.A. Gaudet, E. Schamiloglu, J.O. Rossi, C. J. Buchenauer, and C. Frost Nonlinear Transmission Lines for High Power Applications (survey) Proc. of 28th IEEE Int. Power Modulator Conf., Las Vegas, p. 82, 2008.
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O3-2: High Efficiency Relativistic Magnetron with Diffraction Output
M. I. Fuks, E. Schamiloglu Department of Electrical and Computer Engineering, University of New Mexico,
Albuquerque, NM, USA
A relativistic magnetron with diffraction output (MDO) is a magnetron where the radiation is extracted axially, following the continuation of the anode vanes of the device onto a conical horn antenna whose cross section exceeds cutoff for radiated waves [1]. The MDO possesses unique attractive properties:1) strong resistance to microwave breakdown, unlike conventional magnetrons with radial extraction of microwaves through a narrow slot from one or a few cavities; 2) the MDO and its magnetic field-producing system is compact, unlike conventional magnetrons with radial extraction requiring Helmholtz coils; 3) any eigenmode of the MDO can be selected as the operating wave, unlike magnetrons with asymmetric output, in which only non-azimuthally degenerate modes (that is, the pi- or 2pi -modes) can be used and jump to neighboring modes, leading to the disruption of magnetron operation; 4) in a MDO the operating pi mode can be radiated with any desired mode using the mode converter that is comprised by the continuation of the anode vanes in the conical horn antenna and corresponding to the symmetry of the radiated wave [2]. In earlier experiments with an X-band MDO [1] with tapered continuation of the vanes onto a conical horn antenna, multigigawatt radiated power was demonstrated. Recently, computer simulations [3] for the well-known A6 magnetron were performed in which a diffraction output with expanding continuation of the vanes onto a conical horn antenna have demonstrated incredible enhancement of energy conversion efficiency up to 37%, whereas with the original tapered continuation of the anode vanes the efficiency was only 3% [1]. This impressive result is attributed to a better matching of the interaction space with the antenna, and stimulated us to further optimize the MDO, in particular by using a transparent cathode [4] to drive it. Our previous investigations [4] demonstrated that such a cathode in the A6 magnetron provides fast start-of-oscillations, higher output power and efficiency (unlike what is provided using a conventional solid metal or graphite cathode). As a result of the optimization of the number and azimuthal positions of the emitters, the cathode and anode block lengths, and angles of antenna opening, an energy conversion efficiency of about 60% with gigawatt radiated power for an applied voltage V = 400 kV (that is planned for in experiments) was achieved in MAGIC particle-in-cell simulations. It was also shown in simulations that increasing the
voltage leads to increasing the power as the square of the voltage while maintaining high efficiency operation. [1] L.N. Chekanova, M.I. Fuks, A.A. Kolomensky, et al., Proc. 4th Int. Conference High-Power Beams 81," vol. 2, (Palaiseau, France, 1981), pp. 839-846. [2] M.I. Fuks, N.F. Kovalev, A.D. Andreev, and E. Schamiloglu, IEEE Trans Plasma Sci., vol. 34, pp. 620-626 (2006). [3] M. Daimon and W. Jiang, Appl. Phys. Lett., vol. 91, 191503 (2007 [4] H. Bosman, M. Fuks, S. Prasad and E. Schamiloglu, IEEE Trans. Plasma Sci., 34, pp. 607-619 (2006).
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O3-3: Experimental Verification of the Theory of the Transparent Cathode
S. Prasad, J. Buchenauer, M. Fuks, E. Schamiloglu
Electrical and Computer Eng, University of New Mexico, Albuquerque, United States
The transparent cathode is a hollow cathode with longitudinal sections removed, thereby comprising a discrete number of individual emitters. This cathode was proposed to decrease the start time for oscillations since it is “transparent” for operating modes in magnetrons [1]. The use of this cathode in a magnetron not only offers several different forms of priming (cathode priming, electrostatic priming, and magnetic priming), thereby giving fast start of oscillations but also allows for a large amplitude of the azimuthal component of the RF electric field acting on the electron flow near the cathode surface resulting in fast rate of build-up of oscillations [1,2]. The theory of magnetron operation with transparent cathodes has been verified both numerically using the 3-dimensional particle-in-cell (PIC) code MAGIC and experimentally with an applied voltage of 260 kV in 17 ns pulses using the high current electron accelerator SINUS-6. The well known A6 magnetron design was selected for study. Fast start and rate of build-up of oscillations were observed in the case of the transparent cathode compared to the traditional solid cathode. The fast Fourier transform of the RF signal showed single mode operation in the 2π mode for the magnetron with the transparent cathode, whereas several peaks of different frequencies were observed in the case of the solid cathode indicating mode competition. The microwave power extracted from the magnetron driven by a transparent cathode with 6 discrete emitters was approximately 600 MW while the solid cathode produced only about 150 MW. References 1. M. Fuks and E. Schamiloglu, “Rapid start of oscillations in a magnetron with transparent cathode,” Phys. Rev. Lett., vol. 95, pp. 205101-1-4 (2005). 2. H.L. Bosman, M.I. Fuks, S. Prasad, E. Schamiloglu, “Improvement of the output characteristics of the magnetrons using the transparent cathode,” IEEE Trans. Plasma Sci., vol. 34, pp. 606-619 (2006).
O3-4: Experimental Studies of the Influence of a Resonance Cavity in an
Axial Vircator C. Möller, M. Elfsberg, A. Larsson, S. E. Nyholm Defence & Security, Systems and Technology,
Swedish Defence Research Agency (FOI), Stockholm, Sweden
A vircator (virtual-cathode oscillator) is a narrow-band vacuum cavity oscillator often used as the radiation source in a High-Power Microwave (HPM) system. In a vircator, electrons are emitted from a cathode made of an electron emitting material and accelerated towards an anode, usually made of metal mesh or foil. The electrons passing through the anode form an electron cloud, the virtual cathode, when the space charge limit is reached. To increase the output microwave power of a vircator, a resonance cavity enclosing the virtual cathode is often included in the system. An axial vircator has been designed where it is simple to change the depth of the resonance cavity and the extraction of the microwaves, in order to find an optimum of the cavity size with respect to the output power of radiated microwaves. The microwave radiation is generated both when the electron beam is reflected between the cathode and the virtual cathode and when the virtual cathode oscillates in the resonance cavity. To be able to separate these two sources of radiation the microwaves can be extracted from the side of the anode-cathode gap and/or the cavity side. The vircator is driven by a 400 kV Marx generator. The electron emitter was made of carbon fibre with diameter 55 mm and the anode mesh was made of a set of parallel molybdenum wires. During the experiments, the vircator was radiating into an anechoic chamber. The current through and voltage over the vircator were monitored as well as the radiated microwave field in the chamber. Experimental results are presented for different extraction of microwave radiation and for different depth of the resonance cavity. The radiation intensity is higher, and shows a stronger dependence of the depth of the resonance cavity, from the cavity side than from the anode-cathode gap side.
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O3-5: Relativistic Magnetron Operation with Explosive Emission and
Ferroelectric Plasma Source Cathodes Y. Hadas, A. Sayapin, T. Kweller, Y. E. Krasik
Physics dep., Technion-Israel Institute of Technology, Haifa, Israel
The problem of a reliable electron source is one of a crucial issue in efficient operation of relativistic microwave tubes. In this report we present results of comparison of experimental research of relativistic magnetron operation with commonly used explosive emission plasma cathode and novel ferroelectric plasma source cathode. The latter allows one to form the plasma prior to the accelerating pulse and to control the plasma parameters using different amplitude of the driving pulse and different time delay between the plasma formation and the application of the accelerating pulse. The experiments were carried out using relativistic S-band magnetron powered by Linear Induction Accelerator (~350kV, 4kA, 200ns). Using different time- and space-resolved electrical, optical and spectroscopical diagnostics the plasma parameters (density, temperature and expansion velocity) were studied during the accelerating pulse. In the case of explosive emission plasma it was found that the plasma is not uniform and consists of separate plasma spots whose number increases during the accelerating pulse. It was shown that the microwave generation is accompanied by a significant increase in plasma density and ion temperature, up to ~5•10^16 cm-3 and ~8 eV, respectively. The plasma electron temperature was found to be ~8 eV. It was shown that the plasma expansion velocity in the axial direction reaches ~10^7 cm/s and does not exceed ~2•10^5 cm/s in the radial direction. The application of the ferroelectric plasma cathode allows one to avoid a time delay in the appearance of the electron emission, to achieve better matching between the magnetron and Linear Induction Accelerator impedances, and to increase significantly (~30%) the duration of the microwave pulse with a ~10% increase in the microwave power. These result in a microwave radiation generation to be 30% more efficient compare to the explosive emission cathode use, where efficiency does not exceed 20 %.
O3-6: New Configuration of Virtual Cathode Oscillator
W. Jiang Tsinghua University, Beijing, China
A new configuration of virtual cathode oscillator has been proposed and studied by using three-dimensional particle-in-cell simulations. This microwave oscillator is featured by wide range of operable power level and high beam-to-microwave efficiency. It requires weak external magnetic field to guide and confine the electron beam. The particle-field interaction occurs at the resonance between the virtual cathode oscillation and the electromagnetic mode of the structure, which is substantially different from previous vircators. Intitial simulation results have given microwave conversion efficiency over 20 %.
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O4: High Energy Density Plasmas – Z Pinches
Colonial
Monday, June 29 13:00-14:30
O4-1: Innovative Long Implosion Time Plasma Radiation Sources
H. Calamy1, F. Zucchini1, A. Loyen1, F. Lassalle1, P. Combes1, S. Ritter1, J.F. Cambonie1,
B. Roques1, S. Bland2, N. Niasse2 1Centre d'Etudes de Gramat, Gramat, France
2Blackett Laboratory, Imperial Collega, London, UK
The SPHINX machine [1] developed at Centre d’Etudes de Gramat is based on the 1 microsecond LTD technology and is used as a radiation effects simulator. It delivers a 5.5MA, 800ns current on a Z-pinch load. Efficient plasma radiation sources were obtained especially with the use of multi microsecond prepulse technique [2]. Cylindrical wire array Z-pinches made of a 7 cm radius single array of aluminium wires generates total radiation of 6 TW, 300 kJ with 25 kJ above 1 keV. As the main drawback of this load is its initial dimension that does not allow to work close to the radiation source, Centre d’Etudes de Gramat has started to investigate the potential of more compact wire array loads. Among all the candidates available, radial wire array loads [3] were first tested. In that configuration, wires are radially connecting two concentric electrodes and higher ablation rate close to the cathode generates a magnetic cavity that implodes axially and radially. An evolution of this scheme named Radial Array Focus where the central electrode is extended above the radial array was also tested. The goal of this load was to use the principle of radial array but also to make the axial accelerating region longer. We presents here results of preliminary experiments done on a small test bed (730 kA, 1.2 µs) that was built to study radial wire array loads behavior with long current rise time. Experimental results of radial wire array and radial array focus loads of typical dimensions 70 mm diameter for the anode and between 6 and 50 mm for the cathode are given. We also describe experiments performed at higher current ( 5 MA ) on the Sphinx driver for these two kind of loads. Discussion on the dynamics of these objects and on the parameters of the final radiating region are given as well of 3D MHD simulations with Gorgon code. [1] F. Lassalle et al., IEEE Trans. on Plasma Sciences; Volume: 36, Issue: 2, Part 1 pages 370-377, April 2008. [2] H. Calamy et al., Physics of Plasmas 15, 012701, Jan. 2008 [3] S. Bland et al., “Radial Arrays as Plasma Radiation Source », Wire Array Workshop, Battle, 2007 * Work supported by French Ministry of Defense – DGA/DUM NBC
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O4-2: Plasma Streaming Across Magnetic Field
R. Presura, C. Plechaty, Y. Sentoku, S. Wright, D. Martinez, S. Neff, V. V. Ivanov, Y. Stepanenko
University of Nevada, Reno, Nevada 89557, United States
The effectiveness of diverse phenomena such as the solar wind deflection by planetary magnetospheres, the magnetic field advection in wire array z-pinch precursors, or the operation of magnetically insulated transmission lines may be strongly impacted by plasma penetration across magnetic field. Charge separation due to the plasma-field interaction can lead to penetration in all these instances. Experiments at the Nevada Terawatt Facility addressed the penetration of laser-produced plasma across external magnetic field. Ambient fields with strength up to 60 T, azimuthal symmetry, and 1/r radial dependence were generated in vacuum by driving 0.6 MA current through a cylindrical conductor with the pulsed power generator Zebra. Plasma flows were produced by ablation of solid targets with the short pulse laser Leopard (I ~ 100 PW/cm2). The dynamic plasma-field interaction was investigated for polyethylene plasma expanding along the magnetic field gradient and for stainless steel plasma expanding towards decreasing values of the field strength. The plasma evolution was monitored in the plane perpendicular to the magnetic field with multi-frame laser interferometry and shadowgraphy diagnostics, with 150 ps exposure time, 3 ns inter-frame delay, and 532 nm wavelength. Without magnetic field, the ablation plasma plume expanded quasi-hemispherically, elongated in direction normal to the target. When the magnetic field was present, the plasma plume evolved into a jet-like configuration, well-defined by steep density gradients. The plasma plume became narrower with the distance from the target. The tip of the structure continued to expand with unchanged velocity (~ 300 km/s) for the duration of observation (20 ns). The plasma expansion continued even after the pressure of the ambient magnetic field became significantly higher than the plasma pressure. However, at several mm from the target, where the plume narrowed down, the estimated diffusion time was less than 1 ns, so the magnetic field could diffuse in the plasma during the expansion. One possible explanation of the observations is that the plasma motion across the magnetic field leads to charge separation and, thus, to the onset of an electric field transverse to both the plasma velocity and the magnetic field. In this situation, the E×B drift allows the plasma to continue its expansion with practically unchanged velocity. This explanation is supported by two-dimensional particle-in-cell
simulations used to model plasma penetration across magnetic field.
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O4-3: Numerical Simulations of Thick Aluminum Wire Behavior under
Megaampere Current Drive* S. F. Garanin1, S. D. Kuznetsov1,
W. L. Atchison2, R. E. Reinovsky2, A. J. Awe3, B. S. Bauer3, S. Fuelling3, I. R. Lindemuth3,
R. E. Siemon3 1All-Rusiian Research Institute of Experimental Physics (VNIIEF), Sarov, Russian Federation
2LANL, Los Alamos, New Mexico, USA 3University of Nevada, Reno, Nevada, USA
A series of experiments to study the behavior of thick wires (0.5 mm to 2 mm in diameter) driven by currents of about 1 MA have recently been conducted on the Zebra facility at the University of Nevada, Reno. The objective of these experiments was to study plasma formation on the surface of conductors under the impact of megagauss magnetic fields. Laser shadowgraphy, filtered optical and extreme ultraviolet photodiodes, and extreme ultraviolet spectroscopy used in the experiments provided data on radial expansion of wires and plasma radiation. This paper focuses on numerical simulations of these experiments. Simulations with wires having a diameter of 1.6 mm and less demonstrated plasma formation with temperatures above 3 eV, which is in preliminary agreement with the experiment. For 2 mm diameter wires, although plasma is observed in the simulations, it has substantially smaller optical thickness than in the simulations of the smaller-diameter wires, and the radiation fluxes prove to be much lower. This can shed light on the experimental results, where the radiation of the 2 mm wires was very weak. The simulated time dependences of the wire radii agree rather well with the experimental results obtained using laser diagnostics and light imaging. The experimental data of the photodiodes also agree well with the simulated time dependence of the detected radiation. * This work is based on the results of the investigations conducted under the LANS/VNIIEF Contract #37713-000-02-35, Task Order 037.
O4-4: Current Implosion of Quasi-Spherical Wire Arrays
E. V. Grabovski1, A. N. Gritsouk1, V. V. Aleksandrov1, V. P. Smirnov2,
P. V. Sasorov3, V. V. Fedulov1, I. N. Frolov1, Y. N. Laukhin1, A. N. Gribov1,
S. F. Medovshikov1, K. N. Mitrofanov1, G. M. Oleinik1, A. A. Samokhin1, G. S. Volkov1,
V. I. Zaitsev1 1SRC RF TRINITI, Troitsk, Russian Federation
2Kurchatov Institute, Moscow, Russian Federation
3ITEP, Moscow, Russian Federation
The radiating Z-pinches are supposed to be applied at an irradiation of a thermonuclear target for ICF. For dynamic hohlraum scheme the microtarget is located inside of the cylinder, on which the shock by the outer liner is produced. The critical point is the stream of radiation power on a surface of a microtarget. In paper [1] is shown, that at implosion of quasi-spherical liner instead of cylindrical in the double hohlraum design it is possible to increase a stream of power on a target in 3-4 times. In paper [2] the technology of such liner producing is offered. In paper [3] the implosion of quasi-spherical array consisting of several wires is shown. On Angara-5-1 facility the experiments on implosion of quasi-spherical arrays are carried out. We use wire arrays with mass 250-350 ug, height 15 mm produced from 40-60 wires as a part of a spherical surface of radius 6-10 mm with the removed poles. The medial surface density of these liners was inversely proportional to distance from a surface of sphere up to a symmetry axis. The X-rays was measured by four vacuum X-ray diodes and the 4-shot recording of the X-ray image of the liner with duration ~ 2 ns was performed in quanta 20-700 eV. The previous experiments on conical and biconical liners and RMHD calculation have shown that in case of such loadings the X-ray impulse has the two peaks. The first peak corresponds to implosion of a narrower part of cones and the second to implosion of wider one . In experiments with quasi-spherical arrays also observed two peaks on a X-ray signal. The signal of the data unit XRD2 is produced by more hard quantums than signal of the XRD1. The relation of these signals increases with a radiation hardness. From the X-ray images it is shown that the second peak of radiations corresponds to a moment when the shaping of pinches near to poles is completed and the radiation of the second peak is produced from the center of quasi-spherical array. It testifies to spherical implosion of a part of substance of our quasi-spherical array. The radiation hardness in the second peak which is characterized by the relation of signals XRD2 to XRD1 above than radiation hardness at
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implosion cylindrical liners. It specifies higher temperature of the liner of substance cramped in center of quasi-spherical array. [1] V.P. Smirnov, S. V. Zakharov, E. V. Grabovski, Letters to JETP, 2005. V. 81. N. 9. p 556. [2] T. J. Nash, D. H. McDaniel, R. J. Leeper at al. Phisics of plasmas 12, 052705, 2005. [3] S.V. Lebedev, D.J. Ampleford, S.N. Bland, S.C. Bott, and G.N. Hall, Recent Wire Array Experiments on the MAGPIE Generator, Dense Z-Pinches: 6th International Conference on Dense Z-Pinches, edited by J. Chittenden (2006) СP808, pp. 69 - 72.
O4-5: Trailing and Lost Mass in Z-Pinch Experiment on Angara-5-1 Facility
G. Oleynik TRINITI, Troitsk, Russian Federation
The interest to wire assembly, as to power sources of X-radiation is recently increasing. The current implosion of the wire array looks as the good driver of radiation for achievement of thermonuclear ignition in indirect targets in ICF. Essential problem in physics of implosion of the wire arrays is the problem on that, how much substance remains on periphery of initial wire assembly at the moment of final compression. At the moment of a stagnation of the liner, when its radius is already small, the impedance of the contracting liner can reach some Ohm. The corresponding voltage on a gap 1cm should exceed 1MV. If on periphery of initial wire assembly is present sufficient quantity of well conductive plasma, it can partially shunt a current and the compression with high speed will not realized. It is shown from X-pinch radiography that the plasma formation descends nonuniformly. It appears that in the moment of stagnation some of plasma can be produced on periphery of initial wire array. This plasma just also can partially shunt a current. The estimations demonstrate that the small part of initial mass (some percents) can intercept on itself a noticeable part of a current that can change output parameters of implosion. The research of a problem about that, how much mass is on periphery of initial wire assembly at the moment of final compression, was conducted with the help of a shift laser interferometer. It was received, that mass on peripherals of initial wire array in the moment of stagnation is up to 10% from initial wire array mass. Additional dates were received from analysis of plasma self-luminosity in visible and soft X-ray regions. 2-D time resolved images demonstrate the considerable radiation from periphery of initial wire array in the period of stagnation. Soft X-ray streak camera images show that at the moment of final compression about few percent of total power is radiated from periphery of initial wire array. It is impossible to have radiation without plasma. It means, that plasma exists at periphery of initial wire array. It is possible, that the plasma of such mass really can shunt a part of a current.
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O4-6: X-Ray Backlighting for Early Stages of Wire Array Z-Pinches Using an
X-Pinch T. Zhao, X. Zou, X. Wang, Y. Zhao, Y. Du
Department of Electrical Engineering, Tsinghua University, Beijing, China
In order to investigate the early behavior of wire array z-pinches, a ~500kV/400kA/100ns pulsed power generator (PPG-I) for driving x-pinch was constructed at Tsinghua university recently. PPG- I was composed of a Marx generator, a combined pulse forming line (PFL), a gas-filled V/N field distortion switch, a transfer line, and a vacuum chamber housing the x-pinch (Mo wire) and z-pinch load. The dynamics of x-pinches as well as z-pinches has been investigated by x-pinch x-ray backlighting with PPG-I. To study the evolution of x-pinch, two x-pinches in parallel are mounted between the output electrodes in vacuum chamber. The sequence images of x-pinch at different time were obtained through two x-pinches radiographing each other. Plasma explosion and implosion near the cross point of x-shape wires can be clearly seen in backlighter images. To study the early behavior of the plasma in wire array z-pinches, source X-pinch and object wire array z-pinch were placed in one of the return current rods and between the output electrodes, respectively. Plasma formation, inter-wire plasma merging, and instabilities were also clearly observed, which can provide a better understanding of the physics of z-pinches and basic experimental data to validate simulation models.
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O5: RF/HPM Systems and Effects Ballroom
Monday, June 29 15:00-17:00
O5-1: History and Hardware Behind the Active Denial Technology Capability
D. L. Loree Directed Energy Directorate, Air Force Research
Laboratory, Kirtland AFB, NM, United States
Properly designed high average power 95 GHz millimeter wave transmitters can offer versatile potential to meet emerging requirements across the spectrum of military and domestic security conflict environments. It is a cross domain technology, offering a robust non-lethal weapon capability and potential in other mission areas. Initially developed by Air Force Research Laboratory, Kirtland AFB, NM as the Active Denial System (ADS), this capability is a counter-personnel, non-lethal, directed-energy weapon. Active Denial projects a beam of millimeter waves to induce an intolerable heating sensation on an adversary’s skin, repelling the individual or highly perturbing their activities with minimal risk of injury. It adds to the ability to confirm intent and stop, deter and turn back an advancing adversary, providing an alternative to lethal force. Active Denial System 1 (seen on shows such as Future Weapons, Modern Marvels, and 60 Minutes) was integrated with a substantial hybrid-electric power plant onto a High Mobility Multi-Purpose Wheeled Vehicle (HMMWV) as a technology demonstration system under a DoD Advanced Concept Technology Demonstration program and used in a series of three Military Utility Assessments, testing performance in simulated operational scenarios, with over 3,500 exposures of volunteers. Further potential exists for reducing the size and integrating the technology on a variety of platforms, ground and air. Challenges now are primarily technology development to make the proven capability smaller, lighter, and more agile for the ultimate users. This briefing will highlight the history of the program, describe the basic effect, and detail current hardware configuration emphasizing areas of future technology development.
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O5-2: WBTS HPM a Transportable High-Power Wide-Band Microwave Source
D. Morton1, J. Banister1, T. DaSilva1, J. S. Levine1, T. Naff1, I. Smith1, H. Sze1,
T. Warren1, D. Giri2, C. Mora3, J. Pavlinko3, J. Schleher3, C. Baum4
1L3 Pulse Sciences, San Leandro, CA, United States
2Pro-Tech, CA, United States 3SAIC, ABQ, NM, United States
4University of New Mexico, NM, United States
HPM WBTS (High Power Microwave, Wide-Band Threat Systems) is a high power, repetitively pulsed, wide-band microwave generator capable of 100Hz burst operation. The HPM WBTS microwave capability covers the range of 200MHz to 6GHz in nine frequency bands. E-Field specification at target is 30-110 V/m/MHz depending on frequency. The system is transportable, capable of being set up at remote sites and operation on generator power. The HPM WBTS is composed of several modules all of which store and transport in a standard 40’ container. The pulser and its accompanying power supplies, controls and ancillary systems are housed in a ‘pallet’ structure which can be moved when needed. The system is operated remotely via a fiber-optic linked lap-top computer. The system incorporates built-in diagnostics and data acquisition capability. The HPM WBTS pulser produces burst of microwave radiation using a spiral antenna excited by a short (<1ns, full width half maximum) >2MV negative pulse with a rise-time of <300ps (10-90%). The HPM WBTS is capable of operation at 100Hz with burst lengths of up to 500 pulses**. Rep-rate and burst length are fully programmable. Voltage can be adjusted down to <50% of maximum using a combination of hardware changes and charge voltage adjustment. To cover the 200MHZ to 6GHz frequency range, nine different antennas are utilized. The high pressure SF6 insulated antennas are divided into four groups, each of which is driven by one of four swappable pulse forming lines (PFLs). The HPM WBTS pulse power driver is capable of generating pulses with a slew rate of up to ~6.7x1015 volts per second into the antenna. An accompanying paper at this conference will describe the HPM WBTS pulse power driver and its electrical performance in detail(1). This paper will focus on the overall design, performance and features of the HPM WBTS. Illustrations, specifications and descriptions of field performance will be presented. Radiated E-field measured data will not be included. * The authors would like to thank the Test Resource Management Center (TRMC) Central Test and Evaluation Investment Program
(CTEIP) for their support. This work is funded by CTEIP's Directed Energy Test and Evaluation Project (DETEC) under PEO STRI contract number N61339-00-D-0710-0027. ** Maximum Voltage, Rep-rate and Burst Length Specification are non-concurrent. (1) “A 2MV, <300ps Risetime, 100Hz, Pulser for Generation of Microwaves,” D. Morton, J. Banister, T. DaSilva, J. Levine, T. Naff, I. Smith, H. Sze, T. Warren, D. Giri, C Mora, J. Pavlinko, J. Schleher, C. Baum, IEEE Pulsed Power Conference 2009.
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O5-3: High Power Pulse Burst Generation by Soliton-Type Oscillation on Nonlinear
Lumped Element Transmission Lines J. D. C. Darling, P. W. Smith
Dept. of Engineering Science, University of Oxford, Oxford, United Kingdom
Nonlinear Lumped Element Transmission Line (NLETL) technology is considered to have potential as a source of high power pulse burst waveforms at RF frequencies. Recent work by the Pulsed Power & Plasma Physics Group at the University of Oxford has provided a comprehensive analysis of key trends relevant to the design of such lines, and an enhanced understanding of the phenomenon by which the input pulse to a suitable NLETL may break into a train of high frequency oscillations. The demonstration of efficient coupling of these nonlinear oscillations on to linear loads and antennas has been a key feature of this work. The nonlinear-dispersive Korteweg de Vries (KdV) equation has on several occasions been associated with the electrical transmission line incorporating capacitive nonlinearity, and the individual pulses in the past identified as soliton waves accordingly. The type of oscillation under consideration has been found here to be directly reliant upon the discrete nature of the transmission line and mathematically distinct from other continuous soliton solutions. Despite these observations there are strong indicators that the combination of spatial discreteness and nonlinearity leads to wave trains of a solitonic nature, most closely related to the discrete breathers arising from certain theoretical models of a nonlinear lattice. This paper reports on the latest work in this area alongside high power experimental results as progress is made towards achieving the goal of approaching frequencies of 500 MHz at around 500 MW. With ferroelectric ceramics providing a nonlinear dielectric material, a wide ranging survey has found that the disc cores of a few specific obsolete commercial capacitors offer comparable properties to those likely to be readily available via a bespoke manufacturing process, and at a fraction of the cost. Important design considerations which are applied to the construction of the high power lines include the provision of a large ratio of nominal to fully saturated capacitance values, which may be associated with the barium-titanate based core material of certain high-K capacitors. Whilst good quality oscillation has been demonstrated on a range of lines, it is also important to overcome the problem of extraction to typical load impedances. The Asymmetric Parallel (ASP) arrangement of two lines was conceived with this in mind and promising results have been obtained at low voltages. Experimental work presented will focus on the ASP configuration for
effective extraction of soliton-type pulse burst waveforms, and also investigate the incorporation of propagating antenna capability directly into the transmission line structure.
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O5-4: All-Solid-State 13.56 MHz RF Sources with 20 kW Power
V. M. Efanov, P. M. Yarin, A. V. Kriklenko FID GmbH, Burbach, Germany
A new family of all-solid-state RF power sources with frequency of 13.56 MHz and output power from 1 kW to 20 kW has been developed. Those with output power of 1-2 kW have a volume of about 1 liter and can drive loads ranging from tens of Ohms to several kOhms. They are air-cooled and require input power of 100-200 VDC. The larger sources deliver average power of 10-20 kW into 50-100 Ohm loads. They are water-cooled, with dimensions of 480x500x160 mm. Input power is 100-300 VDC, and the output power is adjusted by varying the input voltage. FID’s new RF sources feature frequency modulation up to 100 kHz, and a computer control interface that provides continuous monitoring of output parameters as well as power adjustment and fault protection. All RF sources of the new series are more than 85% efficient and highly reliable.
O5-5: Use of Radiation Sources to Provide Seed Electrons in High Power
Microwave Surface Flashover* M. Thomas, J. Foster, H. Krompholz, A. Neuber Center for Pulsed Power and Power Electronics,
Department of Electrical and Computer Engineering, Texas Tech University, Lubbock,
TX, United States Delay times of high power microwave surface flashover are affected by radiation illuminating the dielectric. An S-band magnetron is used as source for a 4 MW, 3 μs microwave pulse at 2.85 GHz. This pulse is propagated through a WR-284 waveguide, and its risetime is reduced to 50 ns using a plasma switch pulse steepening technique. A controlled environment of pure Argon at 400 torr was used with 2 mW/cm2 UV-radiation illuminating the test window. Argon was chosen due to its relatively small number of processes involved such as inelastic electron collisions and due to the well-known cross-sections for these processes. Delay times in the presence of UV are significantly shorter than without UV illumination. The initial electron density contribution due the UV source is roughly estimated to be ~106 cm-3. A small admixture of radioactive Krypton-85 showed only marginal changes in the observed delay times, likely due to an insufficient concentration of Kr-85 producing ionization events only every few microseconds. A detailed discussion of experimental breakdown delay data, along with theoretical expectations and statistical analysis, will be given, with the goal of developing a model for HPM window breakdown in UV environment, to describe the role of discharge initiating electrons, and to quantify breakdown at high altitudes. * This work was solely funded by the Cathode and HPM Breakdown MURI program funded and managed by the Air Force Office of Scientific Research (AFOSR).
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O5-6: Short Pulse High Power Microwave Surface Flashover
J. T. Krile, L. M. McQuage, J. Walter, J. Dickens, A. Neuber
Center for Pulsed Power and Power Electronics, Texas Tech University, Lubbock, TX, United
States High Power Microwave (HPM) induced surface flashover is investigated in order to gain a better understanding of this phenomenon and reduce the limitations it imposes on transmitted power levels. This work, utilizing an experimental virtual cathode oscillator (vircator) as HPM source, builds on previous testing that employed a magnetron producing only a few megawatts at 2.85 GHz. Both the previous and current experimental setups are designed to produce a flashover on the high pressure side of a transmission window without the influence of a triple point. While the previous setup was limited to a maximum power of 2.5 MW and a pulse rise time of ~ 50 ns, the vircator is capable of producing 50 MW peak for 100 ns with an adjustable frequency from 3 to 5 GHz and a rise time of < 4 ns. The dominant modes of the vircator and magnetron are the circular TE11 and rectangular TE10 modes respectively, with the major electric field component in both setups normal to the direction of propagation, yielding comparable field geometries at the transmission window. The experimental setup permits the study of flashover factors including gas pressure, composition, temperature, and air speed. Diagnostic equipment enables the analysis of power levels and flashover luminosity with sub-nanosecond resolution. Radiating at 20 MW, the current window design can transmit a 10 ns pulse at a pressure corresponding to 60,000 ft altitude and a 17 ns pulse at 48,500 ft. It is extrapolated that a 100 ns pulse can be transmitted up to an altitude of roughly 33,300 ft under the given conditions. Additional experimental results, including a detailed analysis of the flashover delay times under various conditions, are compared with data from literature and previous testing. * This work was primarily funded by the Cathode and HPM Breakdown MURI program funded and managed by the Air Force Office of Scientific Research (AFOSR).
O5-7: Performance of a Compact Triode Vircator and Marx Generator System
J. Walter, J. Dickens, M. Kristiansen Center for Pulsed Power and Power Electronics,
Texas Tech University, Lubbock, TX, United States
Vircator high power microwave sources are simple, robust, and require no external magnetic field, making them desirable for use in practical compact high power microwave systems. A vircator can be driven directly from the output of a low-impedance Marx generator, eliminating the need for bulky intermediate energy storage components. A compact high power microwave system has been constructed and tested at Texas Tech University utilizing a triode geometry vircator and a compact Marx Generator. The size and performance of this system is compared to a similar system previously developed at Texas Tech. The current triode vircator is housed within a six inch diameter tube which is eleven inches in length. The Marx is contained in an oil tank that is 36 inches long x 12 inches wide x 18 inches tall. Diode voltage and current, and radiated microwave waveforms are presented.
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O6: Pulsed Power Sources – High Current Accelerators
Colonial
Monday, June 29 15:00-17:00
M. G. Mazarakis
O6-1: Linear Transformer Driver (LTD) Development at Sandia National
Laboratory 1, S. Cordova1,
R. G. Gilgenbach2, D. L. Johnson3, A. A. Kim4, K. R. LeChien1, J. J. Leckbee1, F. W. Long1,
M. K. Matzen1, R. G. McKee1, J. L. McKenney1, B. V. Oliver1, J. L. Porter1, V. A. Sinebryukhov4, W. A. Stygar1, D. M. Van De Valde5, K. Ward6,
J. W. Weed1, J. R. Woodworth1 1Sandia National Laboratories, Albuquerque, NM,
United States 2University of Michigan, Ann Arbor, MI, United
States 3L3 Communications - Pulse Sciences, San
Leandro, CA, United States 4High Current Electronic Institute, Tomsk, Russia
5EG&G, Albuquerque, NM, EG&G 6Ktech Corporation, Albuquerque, NM, United
States
Sandia in collaboration with the High Current Electronic Institute (HCEI) in Tomsk, Russia is developing new, fast, high-current, high-voltage induction accelerators based on the Linear Transformer Driver (LTD) technology. LTD based drivers are currently considered for many applications including x-ray radiography, very high current Z-pinch drivers, and Z-pinch IFE (Inertial Fusion Energy). LTD is a new method for constructing high-current, high-voltage induction pulsed accelerators. The salient feature of the approach is switching and inductively adding the pulses at low voltage straight out of the capacitors through low inductance transfer and soft iron core isolation. The pulse forming capacitors and switches are enclosed inside the accelerating cavity. High currents can be achieved by feeding each cavity core with many capacitors connected in parallel in a circular array. High voltage is obtained by inductively adding the output voltage of many cavities in series. Utilizing the presently available capacitors and switches, we can envision building the next generation of fast radiographic and Z-pinch drivers without large Marx generators and voluminous oil-water, pulse forming and pulse compression networks as is the case with the present technology drivers. One of the most significant advantages is that the LTD drivers can be rep-rated. They can be multipulsed with a repetition rate, in principle, up to the capacitor specifications of 10 Hz. The latter makes LTD the driver of choice for z-pinch IFE where the required repetition rate is of the order of 0.1 Hz. Presently we have in Sandia in a single shot operation a 1-MV, 125-kA prototype radiographic voltage adder with seven LTD cavities connected
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in series, a larger 0.5-MA, 100-kV LTD cavity in a rep-rated operation, and a large 1-MA LTD cavity operating in a single shot mode at the University of Michigan. In parallel we are preparing a new LTD laboratory, named MYKONOS, to house our 10, 1-MA, 100-kV LTD cavities recently constructed and received from the HCEI in Tomsk, Russia. The cavities are stackable and will be assembled in a 1-MV, 1-MA voltage adder configuration enclosing deionized water as an insulator. This will be the first induction voltage adder constructed and operated with a water filled coaxial transmission line. Experimental results obtained with the prototype radiographic accelerator, the 0.5-MA and 1-MA cavities, progress of the new 1MV, 1MA, MYKONOS laboratory, and future plans for both radiographic and high current accelerators will be presented. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energys National Nuclear Security Administration under Contract DE-AC04-94AL85000.
O6-2: Positive-Polarity Power Flow in Multiple-Adder MITLs*
J. W. Schumer, P. F. Ottinger, R. J. Allen, D. Hinshelwood, S. B. Swanekamp
Plasma Physics Division, Naval Research Laboratory, Washington, DC, United States
To efficiently couple a self-pinched ion-diode (SPD) with a positive-polarity, high-impedance (20 - 40 Ohms) inductive voltage adder (IVA), a detailed understanding of electron power flow in the vacuum magnetically-insulated transmission line (MITL) section is required. Such an ion diode could be used for the production of an intense ion beam pulse (4-8 MeV, 20-100 kA, 50 ns), suitable for a variety of DOE and DoD applications. In the positive-polarity MITL, the center conductor is the anode and the outer conductor is the cathode/emitter surface. To complicate matters, high-voltage IVA architectures are constructed by joining multiple inductive cells to form the outer conductor (i.e. cathode); thus, electrons are “born” at different potentials and execute complicated orbits within the MITL, forming what is referred to as layered flow. The cumulative effect of these layered electron populations results in lower effective MITL impedance than the usual flow impedance, altering the machine-to-load coupling and potentially loading down the driver. Whereas a large body of work has been devoted to the understanding of electron power flow in a simple MITL, much less attention has been paid to the electron dynamics in this more complicated, positive-polarity MITL within an IVA. What previous work that is available [1] is expanded upon here. Results from PIC simulations using LSP [2] will be presented, as well as comparisons to recent experiments on Mercury and Hermes, both operating in positive polarity with a self-pinched ion diode. *Work supported by DOE through SNL. a L3 Communications. [1] C.W. Mendel and S.E. Rosenthal, Phys. Plasmas 2, 1332 (1995). [2] LSP is a software product of ATK Mission Research, Albuquerque, NM 87110.
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O6-3: Conceptual Designs for an Upgrade of the Sphinx Z-Pinch Driver
F. Lassalle, A. Georges, B. Roques, H. Calamy, A. Loyen
Centre d'Etudes de Gramat, Gramat, France
The SPHINX machine (1) developed at Centre d’Etudes de Gramat is based on the 1 microsecond LTD technology and is used as a radiation effects simulator. It operates in direct drive mode with 16 branches of 10 LTD stages each and delivers a 5.5MA, 800ns current on a Z-pinch load. With 2.2 MJ stored energy and a load 7cm radius made of a single array of aluminum wires, total radiation is 6TW, 300kJ with 25kJ above 1keV. We investigate several conceptual driver designs to improve radiation outputs from aluminum and argon loads and also to be able to drive higher Z loads like titanium, stainless steel or copper. The analysis focuses on two architectures based respectively on the 100ns LTD technology (2,3) and the 1 microsecond LTD technology (1). Two designs giving approximately same driver size (building availability specification) and comparable driver cost (funding specification) are compared. Details on LTD stages designs and drivers architectures are given. These designs correspond respectively to a 0.8MJ, 6MA, 200ns driver and a 9MJ, 19MA, 1400ns driver. Yield analysis is based on performances measured on fast Z-pinches (200ns) and performances extrapolated at currents above 6MA for slow Z-pinches (800ns). This analysis shows that the microsecond driver, compared to the 200ns one can be up to eight times more efficient in terms of cost/Joule of radiated energies. Improvements under study and innovative developments on long implosion time plasma radiation sources (4) would further confirm in the future the interest of the compact and low cost microsecond LTD technology. 1. F. Lassalle et al., “Status on the Sphinx Machine Based on the Microsecond LTD Technology”, IEEE Trans. On Plasma Sciences, Volume 36, Issue 2, Part 1 pages 370-377, April 2008 2. Centre d’Etudes de Gramat contract with HCEI-ITHPP on development of a 1MA, 100ns LTD stage working with atmospheric dry air insulation 3. W. A. Stygar et al.; « Architecture of petawatt-class z-pinch accelerators », Phys.Rev. 10, 030401 (2007) 4. H.Calamy et al., this conference. ____________________________ * Work supported by French Ministry of Defense – DGA/DUM NBC
O6-4: Polarity Inversion on Saturn V. J. Harper-Slaboszewicz1, K. A. Mikkelson1,
B. V. Weber2, D. P. Murphy2, R. J. Commisso2, J. R. Goyer3, J. C. Riordan3
1Sandia National Laboratories, Albuquerque, NM, United States
2Naval Research Laboratory, Washington, DC, United States
3Pulsed Sciences, L3 Communications, San Leandro, CA, United States
The Saturn accelerator is a 10 MA, 2 MV, 50 ns, negative polarity pulsed power driver using nested radial MITLs to drive low impedance loads [1]. In the past, operating Saturn in positive polarity has required modifying water section components to invert the polarity in the water. In addition, for full-power operation, restacking the vacuum insulator to reverse the insulator angles would be required. To reduce the time and effort required to field loads requiring positive polarity, an innovative method of inverting the polarity in vacuum has been implemented. This method makes use of two enabling elements. First, to minimize losses associated with convoluting the power in vacuum, only one stack module comprising one radial triplate MITL is used. Modified components in the water section combine the power from the two outputs of the water triaxial transmission lines to drive a single triax in vacuum. Second, a single post-hole convolute, developed to support the fielding of a large diameter gas gun, is used to convolute the power flow from the triplate feed to a coaxial transmission line. To invert the polarity, the negative-high-voltage inner conductor of this coaxial line is connected to ground through a ballast inductance. The load is connected inside this ballast inductance, so that the polarity is inverted at the load. Current and voltage diagnostics were fielded on short circuit shots to verify the polarity inversion, and load shots have demonstrated the ability to deliver 800 kV, 3 MA, 50 ns power pulses to a positive polarity bremsstrahlung load. [1] Smith, B. L.; Boyes, John D.; Robischon, Steven J.; Woolston, T. L.; Douglas, G. M.; Franklin, T. L.; Hart, J. M.; Ives, Harry Crockett, III; Cap, Jerome Scot, Engineering design of the Saturn accelerator, presented at the 6th IEEE Pulsed Power Conference, June 29- July 1 1987, Arlington, VA.
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O6-5: Circuit Modeling Techniques Applied to ZR
P. A. Corcoran1, B. A. Whitney1, V. L. Bailey1, L. G. Schlitt2, M. E. Seiford3, J. W. Douglas4,
M. E. Savage1, W. A. Stygar3, I. D. Smith1 1L-3 Systems /Pulse Sciences, San Leandro, CA,
United States 2Leland Schlitt Consulting Services, Estes Park,
CO, United States 3Sandia National Laboratory, Albuquerque, NM,
United States 4John Douglas Consulting Services, Tucson, AZ,
United States
An overview of a transmission line based circuit model for ZR is presented along with a comparison of its output to experimental measurements of ZR driving a short circuit load (Shots 1780, 1852) and a z-pinch wire load (Shot 1785). The circuit model includes a 2-D network of transmission lines that was used to model the 2-D and 3-D aspects of ZR’s output transmission lines and water convolute. The development of the 2-D network is discussed along with benchmarks to a 3-D LSP-based model. The various switch parameters needed to match the measured waveshapes are also discussed.
O6-6: Testing of a 1-MV Linear Transformer Driver (LTD) for Radiographic Applications
J. J. Leckbee1, S. Cordova1, B. V. Oliver1, D. L. Johnson2, M. Toury3, R. Rosol3, B. Bui4
1Sandia National Laboratories, Albuquerque, NM, United States
2L3 Communications - Pulse Sciences, San Leandro, CA, United States
3CEA-DAM, Polygone d'Experimentation de Moronvilliers, Pontfaverger-Moronvilliers, France
4Ktech Corporation, Albuquerque, NM, United States
The linear transformer driver (LTD) is a promising new pulsed power technology with applications including high voltage flash x-ray radiography and high current Z-pinch drivers. A LTD cavity is similar to a traditional inductive voltage adder (IVA) cavity, however the primary energy storage is packed inside the cavity. The resulting architecture is more compact than a traditional Marx generator driven IVA. The 1-MV LTD is designed to supply 125 kA in a 100-ns FWHM voltage pulse without the optional peaking capacitors. A single cathode stalk is threaded through the centers of the seven series cavities forming a coaxial magnetically insulated transmission line (MITL). The MITL is terminated with a large area electron beam diode. Electrons are emitted from the surface of the aluminum cathode, accelerated across a vacuum gap (referred to as the anode-cathode or AK gap), and strike the carbon anode producing an approximately 75-ns FWHM x-ray pulse. Individual cavities were tested with various resistive load impedances. Experiments with large area electron beam diodes of varying impedance were used to evaluate the performance of the 1-MV LTD under loads similar to radiographic diodes. ____________________________________ * Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000. ** This work was performed under the auspices of an agreement between CEA/DAM and NNSA/DP on cooperation on fundamental sciences.
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O6-7: Design and Tests of Induction Cavity for 3MV IVA Accelerator
P.T. Cong, A. C. Qiu, H. L. Yang, F. J. Sun, G. W. Zhang, H. Y. Wu
Northwest Institute of Nuclear Technology, Xi'an, China
The Induction Voltage Adder (IVA) is a three stages, 3MV, 60kA，70ns FWHM accelerator designed to study rod-pinch diode (RPD) where the bremsstrahlung radiographic source is generated. The IVA accelerator has three 1MV, 70ns inductively isolated cavities connected in series through a high voltage, vacuum insulating transmission line (VITL). The transfer efficiency of current from the cavity primary circuit to the diode is 0.9, and the maximum field of 200kV/cm on the negatively stressed surface of VITL is below electron emission threshold. Each inductive cell contains 840kg pre-annealed amorphous magnetic cores whose size parameters are determined by the current transfer efficiency and electron emission field. The experimentally measured results of maximum relative permeability of amorphous magnetic cores under pulse excitation are consistent with saturation wave model when dB/dt is greater than 10T/μs . The ratio of the remanent flux density to the saturation magnetic flux density (Br/Bs) is about 0.5 for the produced large magnetic cores. The analysis of electric field for cavity with cores and azimuthal transmission line is carried out, and the ratio of operation field stress to the critical breakdown field stress is about 0.5. The results of tests for design verification of electric field safety and magnetic core performance are reported. With saturable magnetization inductance and resistance of eddy current being calculated for inductive cell, the IVA accelerator circuit model is provided, and the simulation predictions are presented and compared with the experimental results. Key words: Inductive voltage adder; Magnetic cores; Azimuthal transmission line; Circuit model; Electric field
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TUESDAY
JUNE 30
O7: Explosive Pulsed Power 1
O8: High Energy Density Plasmas – Applications
O9: Intense Electron and Ion Beams and Plasmas
O10: Pulsed Power Switches and Components – Closing Switches
O11: Pulsed Power Switches and Components – Solid State Switches
O12: Explosive Pulsed Power 2
O7: Explosive Pulsed Power 1 Ballroom
Tuesday, June 30 10:00-12:00
O7-1: Use of Ferroelectric Generators for
RF Applications A. H. Stults
WDI, Aviation and Missile Research Development and Engineering Laboratory,
Redstone Arsenal, AL, United States
Three different explosive shock wave generators were tested for use in direct drive, no balun use of of ferroelectric generators to drive RF antennas. The antenna for this set of comparison was a rectangular sinuous antenna used to maximize low frequency performance in a given, restrictive form factor. Unique characteristics of PNZT 95/5/2 and a sinuous antenna are explained and experimentally illustrated
O7-2: Development of Ferroelectric Materials for Explosively Driven Pulsed
Power Systems E. F. Alberta1, W. Hackenberger1, B. Freeman2,
D. J. Hemmert3, A. H. Stults4, L. Altgilbers5 1TRS Technologies Inc., State College, PA,
United States 2Ktech Corp., Albuquerque, NM, United States
3HEM Technologies, Lubbock, TX, United States 4U.S. Army AMRDEC, Huntsville, AL, United
States 5U.S. Army SMDC, Huntsville, AL, United States
First demonstrated in the 1950s, ferroelectric generators (FEG) have been shown to be versatile compact pulsed-power sources. An FEG works by subjecting a ferroelectric ceramic to a high-pressure shock-wave typically produced by a high-explosive charge. The resulting compression causes the ferroelectric to release the electric charge stored within its crystal structure. Most explosively-driven FEG research has used commercial-off-the-shelf piezoelectric compositions such as lead zirconate-titanate ( Pb(Zr0.48Ti0.52)O3, i.e. PZT ). Although these materials can be used to demonstrate pulsed-power and RF weapons concepts, they do not deliver enough energy to field compact devices. To solve this problem a manufacturing process was developed to produce a higher energy-density composition known as PZT-95/5 ( Pb(Zr0.95Ti0.05)O3 ). This material, originally developed by Sandia National Laboratories in the 1960s, is capable of storing much more energy than commercially available PZT materials and is also capable of releasing all of its stored energy very rapidly (~ 1 s) by virtue of a pressure-induced phase transition. This paper discusses the development, testing, and scale-up of TRS Shock-HV FEG material. This modified PZT-95/5 has been demonstrated to provide 2 to 3 times more power output than state-of-the-art materials. This new material will allow the development of a new generation of powerful, yet compact, FEG-based devices thus enabling a broad range of man-portable pulsed-power devices and RF weapons
O7-3: Prediction of Compact Explosively- Driven Ferroelectric Generator
Performance D. W. Bolyard, A. Neuber, J. T. Krile, J. Dickens,
M. Kristiansen Center for Pulsed Power and Power Electronics,
Department of Electrical and Computer Engineering, Texas Tech University, Lubbock,
TX, United States
Explosively-driven ferroelectric generators are attractive as potential prime energy sources for one-time use pulsed power systems. While the output voltages and energies of small ferroelectric discs have been shown to be on the order of the theoretical maximum values, scaling the ferroelectric to larger thicknesses has proven less successful. The primary limiting factors are how much of the ferroelectric material is compressed simultaneously, as well as how evenly the pressure pulse compresses the ferroelectric material. Both are difficult to control for thicker ferroelectric discs or stacks of discs due to pressure pulse attenuation in the material and rarefaction waves shortening the pressure pulse. Experimentally determining the spatially resolved pressure pulse in the ferroelectric is next to impossible; the primary quantity accessible in the experiment is the output voltage pulse of the shocked material. Hence, a hydrodynamic code system (CTH, developed by Sandia National Laboratories) is utilized to calculate the temporally and spatially resolved pressure. The calculated pressure values are converted into voltage produced by the ferroelectric through an algorithm based on an empirical polarization-pressure hysteresis curve. The validity of the algorithm has been verified for PZT EC-64 with experimental data from a flyer plate experiment reported in literature and our own experiments with the shock wave from the explosives more directly applied to the ferroelectric. Both calculations and experiments produced output voltages, normalized to the thickness of the ferroelectric, ranging from 1.4 to 3.4 kV/mm for one inch diameter discs. We will discuss how this pressure to voltage algorithm along with pressure simulations aided in the scaling of the amount of ferroelectric material in an explosively-driven ferroelectric generator, as well as in the design of new driver elements with the goal to increase the peak output voltage of a generator while keeping the generator compact. The calculated voltage output results will be compared with experimental data of explosively-driven ferroelectric generators.
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O7-4: Electrical Conduction in Select Polymers under Shock Loading
C. F. Lynn, A. Neuber, J. T. Krile, J. Dickens, M. Kristiansen
Electrical Engineering, Texas Tech University, Lubbock, TX, United States
It is known that polymers become conductive under shock loading, which can be detrimental to the operation of explosive driven high current/voltage devices. Hence, the electrical characteristics of several select insulating materials under extreme pressure were investigated. Four polymers Nylon, Teflon, Polypropylene, and High Density Polyethylene, were tested under shock pressures up to ~23 GPa. Shock waves were generated with high explosives, and CTH, a hydrodynamic code developed at Sandia National Laboratories, was utilized to calculate pressure and temporal resolution of the shock waves. Time of arrival measurements of the shock waves were taken to correlate the hydrodynamic calculations with experimental results. A notable delay between shock front arrival and the onset of conduction is exhibited by each polymer. The delay tends to decrease with increasing pressure down to approximately 500 ns for HDPE at ~23 GPa under electric field strength of ~6.3 kV/cm. The polymer, under the aforementioned conditions, conducted for ~5 us before recovering to an insulating state. At pressures of ~5 GPa and electric field strength of 6.3 kV/cm the delays range from ~5 us to ~20 us. There is a significant variance in the measured delay for each polymer; however, it is clear that some polymers exhibit more delay than others, thereby indicating better insulating properties under shock loading. Additionally, it was shown through experiments that the polymers conducted for a finite time on the microsecond time scale before recovering back to an insulating state. This recovery from a shock wave induced conducting state back to insulating state was investigated for possible use as a novel opening switch. **subject to approval for public release
O7-5: A Helical Magnetic Flux Compression Generator with a Conical
Armature Z. W. Dong, C. Y. Yu, Q. Zhao, X. J. Yang
Institute of Applied Physics and Computational Mathmatics, Beijing, China
The helical magnetic flux compression generator (HMFCG) driven by high explosive is widely used in a variety of high-energy and high current applications, especially in a single shot at remote location applications. Although general principles of HMFCG are reasonably well documented, the desire to design an HMFCG with a higher efficiency and versatility is still being remained by most of research groups even now. A two-dimensional magnetic hydrodynamic (MHD) code used to model the dynamic behavior of magnetic flux compression generators with helically wound coils，known as MFCG-IV is developed. In this paper the influence of a conical armature on the process of the magnetic flux compression in a simply HMFCG is analyzed and simulated systematically by using code MFCG-IV. Simulation results show that output power of an HMFCG with a conical armature can be enhanced, but generally its output energy is reduced.
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O7-6: Performance of a Compact, Cascade FCG System
J. V. Parker1, C. E. Roth1, F. M. Lehr2, S. K. Coffey3, J. H. Degnan2
1Science Applications International Corporation, Albuquerque, NM, United States
2Directed Energy Directorate, Air Force Research Laboratory, Albuquerque, NM, United States
3Numerix, Inc, Albuquerque, NM, United States
A flux compression generator (FCG) with high energy gain generally exhibits low flux transport efficiency. This problem can be addressed by using a cascade of two (or more) FCGs coupled together by inter-stage transformers. The transformer provides flux gain to overcome the flux loss in the previous FCG. This technique is effective, but unattractive in some applications due to the size and weight of the coupling transformer. An alternative to using an external transformer is magnetic coupling directly to the windings of the FCG, the so-called flux-trapping technique. In this paper we describe a system of two FCGs coupled via flux-trapping. The driver FCG, designated SAM, is a 10 cm diameter by 49 cm long, 286 uH device that was custom-designed for this application. The output of SAM is a single-turn loop that is tightly coupled to the first winding section of a larger FCG, designated JILL. The JILL generator is a 26 cm diameter by 79 cm long, 314 uH FCG designed to drive a load inductance in the range 0.5 to 2 uH. The single-turn driver loop, coupled to the 35 turn input winding of JILL, provides a calculated flux gain of 28. The first experimental test of the SAM/JILL system was conducted in July 2008 at the Air Force Research Laboratories Chestnut test site. The SAM generator was seeded with 1.0 kA (flux 0.29 Wb) and produced a current of 472 kA (flux 0.10 Wb) in the coupling loop at crowbar time of the JILL generator. Based on the calculated mutual inductance of 5.95 uH, the JILL generator began operation with a seed flux of 2.81 Wb. With this seed flux, the expected output current for JILL driving a 0.8 uH load is 1.8 MA. The measured output current was 884 kA, roughly one half of the expected current. Analysis of the I-dot data from the test shows that this low performance was due to multiple electrical breakdowns in the JILL generator during the interval when the armature-stator contact point was underneath the coupling loop. Subsequent analysis suggests that the electrical breakdowns were the result of flux compression in the coupling loop. Details of the experiment and analysis will be presented. A modification to the SAM/JILL apparatus has been proposed to eliminate electrical breakdown. This proposed
modification will be discussed and experimental results, if available, will be presented.
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O7-7: Ultra-Compact High Efficiency Multi-Kilovolt Pulsed Power Source
Z. S. Roberts, Z. D. Shotts, M. F. Rose Radiance Technologies, Huntsville, Alabama,
United States
Single shot high power, high energy pulsed electrical sources have been investigated over the years and encompass magnetic flux compression generators, MCG, at the high energy high power end of the scale to Ferroelectric generators, FEG, and ferromagnetic generators, FMG, at lower energy but still high power. While most of the reported research (see the Proceedings of the Pulsed Power Conferences) has concentrated on the pulse generators themselves, a complete pulsed power train encompassing all elements of a pulsed power system has not been adequately studied or optimized within the context of miniature sizes. In this paper, we will describe recent experiments aimed at producing a pulsed electrical system consisting of a FEG [1], a resonant energy transfer element, high speed switching (either dielectric puncture or explosive), a Vector Inversion Generator configurable as an oscillator [2,3], and a means to combine them into an efficient system that delivers maximum energy to a load at voltages in excess of 100 kV. Pulse compression ratios for this system are on the order of 1000, from microsecond electrical pulses from the FEG to nanosecond pulses from the VIG. In its final embodiment, the finished pulse generator will be on the order of 1.5 inches in diameter and approximately 8 inches long and capable of delivering a fast high voltage pulse ( ~ 9ns rise time, 200 kV max) at energy levels of joules to the load. Further since it is made of inert materials, it should have an infinite shelf life. The basic proof-of-principle experiment was reported in the 2005 Pulsed Power Conference [4]. In this work, we will describe recent experiments to develop resonant energy transfer from the FEG to the VIG at high efficiency, the development of explosive/dielectric switching at kilovolt levels and the explosive testing of prototype FEG/VIG configurations that constitute laboratory prototypes sufficient for modeling and simulation. Preliminary data showing high frequency oscillation for the FEG/VIG configured as an oscillator will be presented and analyzed in terms of possible antenna configurations and breakdown issues. The power conditioning technology researched herein is relevant to all sizes of single pulse generators and this work constitutes the first demonstration of an ultra-compact scalable power conditioning subsystem that is an energy source element, a dynamic impulse generator, and a generator of RF energy at a frequency controllable by the user in a single
compact system with only two dynamic components
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O7-8: Circuit Modeling of a Power Conditioning Circuit with an
Electroexplosive Opening Switch K. A. O'Connor, R. D. Curry
Center for Physical and Power Electronics, University of Missouri-Columbia, Columbia, MO,
United States
Power conditioning systems utilizing inductive energy storage require an opening switch to transfer energy to the system load. Electroexplosive opening switches are often implemented due to their long conduction time of large currents, as well as the rapid change of impedance, and high dielectric strength. Due to the complex relationship between the circuit current and switch impedance, numerical modeling methods are required to understand the dynamic switch and circuit behavior. The resistivity of electroexplosive opening switches can be described in terms of the specific energy dissipated in the switch or the specific action. The specific energy and specific action are dependent on the integral of the square of the current through the switch. The current through the switch is also dependent on the impedance of the switch. Therefore, an iterative process using numerical methods is required to model the switch resistivity and its effects on circuit behavior. A Matlab program was written to simulate an electroexplosive opening switch in a power conditioning circuit with an inductive energy store. The program was developed assuming the source was a flux compression generator, but additional sources can be modeled. An inductor or a transformer can be used as the inductive energy storage element. The program can allow simulation of a resistive load, representing a high power microwave source, the capacitive load of a high power RF source, or an inductive load. A detailed description of the development of the program is provided. Simulation results are included for an exploding wire fuse with a resistive and a capacitive load.
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O8: High Energy Density Plasmas – Applications
Colonial
Tuesday, June 30 10:00-12:00
O8-1: Numerical Simulation of Metallic Surface Plasma Formation by Megagauss
Magnetic Fields I. R. Lindemuth1, R. E. Siemon1, B. S. Bauer1,
M. A. Angelova1, W. L. Atchison2, S. F. Garanin3, V. Makhin4
1University of Nevada, Reno, NV, United States 2Los Alamos National Laboratory, Los Alamos,
NM, United States 3All-Russian Institute of Experimental Physics,
Sarov, Russia 4NumerEx, Albuquerque, NM, United States
Plasma formation on the surface of thick metal in response to a pulsed multi-megagauss magnetic field is being investigated at the University of Nevada, Reno (UNR) with well-characterized experiments [1,2]. Aluminum rods with 0.5-2 mm diameter are pulsed with the 1.0-MA, 100-ns UNR Zebra generator. The rod radii are larger than the magnetic skin depth. A novel rod mechanical connection eliminates non-thermal precursor plasma, which in earlier experiments was produced by electric-field-driven electron avalanche and arcing electrical contacts. The rod surface has been examined with time-resolved imaging, pyrometry, spectroscopy, and laser shadowgraphy. A number of US and Russian radiation-magnetohydrodynamic (R-MHD) codes are being used to help interpret the experimental results such as time of plasma formation and rate of current channel expansion. The code results are sensitive to the equation-of-state and resistivity models used as well as computational parameters such as zoning and time-step size. All codes and EOS/resistivity combinations predict plasma formation for at least some, but not always all, rod sizes for which plasma formation is observed experimentally. The best results obtained to date with the UNR code MHRDR use the standard SESAME Maxwell-construct EOS and a Russian resistivity model, and the computed times of formation agree remarkably well with the observations across the full range of wire diameters. This leads to the conclusion that plasma formation is indeed an MHD effect and does not involve the non-MHD processes often invoked in other contexts. The computations show that plasma is formed in low-density material that is resistive enough to expand across the magnetic field and yet conductive enough that Ohmic heating exceeds expansion cooling as the expanding material undergoes the liquid-vapor transition. Analytic modeling based upon examining the characteristic Ohmic heating time and other characteristic times shows that plasma formation
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should indeed be expected at the high electric fields involved and that the formation observed in the computations is not a fictitious numerical effect. 1. S. Fuelling et al., IEEE Trans. Plasma Sci. 36, 62 (2008). 2. R.E. Siemon et al., J. Fusion Energy 27, 235 (2008).
O8-2: Wire Explosion in Vacuum: Velocity of Current-Carrying Corona and
Strata Formation R. Baksht1, A. Rousskikh2, V. Oreshkin2,
I. Beilis1 1Tel Aviv University, Tel Aviv, Israel
2Institute of High Current Electronics, Tomsk, Russia
Composition of a current-carrying layer at wire explosion (WE) in vacuum plays the important role at wire-array implosions. Experimental data show that a wire explosion in vacuum is accompanied by the formation of a low-density plasma corona surrounding a denser core [1, 2] and by the appearance of strata [1] - alternating layers of material of increased and decreased density. The time of the corona appearance coincides with the time of a voltage collapse. The report presents the results of measurements of a current-carrying corona expanding velocity. The measurements were performed for Al and W thin wires at current densities of 10E8 Amper per square centimeter. The velocity was measured using a collector. The cylindrical brass collector of inner diameter 18 mm was placed coaxially between the wire and the return conductors. Detected velocity of the current-carrying corona has reached (3-7)10E6 cm/s for W wires of diameter 6 μm. Magnetohydrodynamic simulation reproduces the main features of the wire explosion. In the previous paper we have shown [3] that strata are formed before the voltage collapse, that is, at the stage of heating of the wire metal. To observe the strata, the soft x-radiation generated at the hot point of an x-pinch was used.The stratification is most probably due to the thermal instability that develops as a consequence of the increase in metal resistivity with temperature [4]. The report shows the development of further study of the strata formation. We discuss also the probable effect of the strata formation on the corona expanding velocity. 1. Exploding wires // Edited by Chace W.G. and Moor H.K. N.Y.: Plenum Press, 1959; 1964; 1965; 1968; Vols.1- 4. 2. I.M.Vitkovitsky and V.E.Sherer, J.Appl. Phys, 52, 3012 (1981). 3. A. G. Rousskikh V. I. Oreshkin, S. A. Chaikovsky, N. A. Labetskaya, A. V. Shishlov, I.I. Beilis and R.B. Baksht, Physics of Plasmas 15 (11), (2008). 4.V.I.Oreshkin, Phys. Plasmas, 15 092103 (2008).
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O8-3: Warm Dense Matter: Another Application for Pulsed Power
Hydrodynamics R. E. Reinovsky
Applied Physics Division, Los Alamos National Laboratory, Los Alamos, NM, United States
Pulsed Power Hydrodynamics (PPH) is an application of low-impedance, pulsed power, and high magnetic field technology to the study of advanced hydrodynamic problems, instabilities, turbulence, and material properties. PPH can potentially be applied to the study of the properties of warm dense matter (WDM) as well. Exploration of the properties, such as equation of state, viscosity, conductivity of warm dense matter is an emerging area of study focused on the behavior of matter at density near solid density (from 10% of solid density to slightly above solid density) and modest temperatures (~1-10 eV). Conditions characteristic of WDM are difficult to obtain, and even more difficult to diagnose. One approach uses laser or particle beam heating of very small quantities of matter on timescales short compared to the subsequent hydrodynamic expansion timescales (isochoric heating) and a vigorous community of researchers are applying these techniques. Pulsed power hydrodynamic techniques, such as large convergence liner compression of a large volume, modest density, low temperature plasma to densities approaching solid density or through multiple shock compression and heating of normal density material between a massive, high density, energetic liner and a high density central “anvil” are possible ways to reach relevant conditions. Another avenue to WDM conditions is through the explosion and subsequent expansion of a conductor (wire) against a high pressure (density) gas background (isobaric expansion) techniques. However, both techniques demand substantial energy, proper power conditioning and delivery, and an understanding of the hydrodynamic and instability processes that limit each technique. In this paper we will examine the challenges to pulsed power technology and to pulsed power systems presented by the opportunity to explore this interesting region of parameter space. *This work performed under the auspices of the US Department of Energy.
O8-4: Effect of External Magnetic Field on Shaped-Charge Operation
G. A. Shvetsov1, A. D. Matrosov1, N. N. Marinin1, S. V. Fedorov2, A. B. Babkin2, S. V. Ladov2
1Lavrentyev Institute of Hydrodynamics, Novosibirsk, Russian Federation
2Bauman Moscow State Technical University, Moscow, Russian Fegeration
The present paper considers the possibility of using external magnetic fields for the antiterrorist protection of various objects against shaped-charge action by means of their magnetic screening – the creation of a magnetic field in the space ahead of the object being protected from attack [1]. The results of experimental and numerical investigations of the effect of the magnetic field generated in a shaped-charge liner on the structure of the shaped charge jet formed and jet penetration into a target are presented. Emphasis is placed on large-scale effects It is shown that a considerable decrease in the depth of penetration of shaped-charge jets into a target can be achieved at moderate magnetic fields of a few tenths of a tesla. The physical mechanisms involved in the disruption of shaped-charge jets are discussed. The results of the experiments and numerical calculations confirm that the “magnetic protection” of objects from shaped-charge warheads is in principle possible. 1. G. A. Shvetsov, A. D. Matrosov, S. V. Fedorov, A. V. Babkin and S.V. Ladov “Magnetic Screening Against Shapaed-Charge Action”, 2007 IEEE Pulsed Power and Plasma Science Conference, June 17–22, 2007, paper 3P120.
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O8-5: Explosive Magnetic Liner Devices to Produce Shock Pressures up to 3 TPa A. M. Buyko1, S. F. Garanin1, Y. N. Gorbachev1,
G. G. Ivanova1, A. V. Ivanovsky1, I. V. Morozova1, V. N. Mokhov1, A. A. Petrukhin1, V. N. Sofronov1, V. B. Yakubov1, W. L. Atchison2,
R. R. Reinovsky2 1All-Russian Research Institute of Experimental Physics (VNIIEF), Sarov, Russian Federation
2LANL, Los Alamos, New Mexico, USA
The paper considers liner devices with a 15-module 0.4 meter diameter disc explosive magnetic flux compression generator (DEMG) that are close to the device with a similar 10-module DEMG successfully tested in joint VNIIEF/LANL experiments ALT-1,2. The devices are intended for testing the possibility of producing 1 3 TPa shock pressures and for measuring Hugoniots of different materials at such pressures. Basic differences of the physical design of the devices and their diagnostic suites from those used in ALT-1,2 are described. Basic simulated performance characteristics of the pulsed power system and liner assemblies of these devices are presented and discussed. The values of current, energy and power that can be delivered to the liner load are ~ 70 MA , ~ 40 MJ and ~ 20 TW; these are a factor of ~ 2, ~ 4 and ~ 7, respectively, higher than in ALT-1,2 simulations. Magnetic fields on cylindrical impacting liners having initial radii of ~ 4 cm can reach ~ 6 MG, with peak velocities of 2 mm thick Al liners at an impact radius of 1 cm growing as high as ~ 27 km/s (in the ALT-1,2 devices: ~2 MG and ~ 12 km/s). The paper focuses on two-layer impacting liners accelerated to ~ 20 km/s and composed of an outer current carrying aluminum layer and an inner iron or tungsten layer that produces impact and according to 1D simulations remains solid in the process of implosion.
O8-6: Pulsatile Behavior of a Helical D.C. Arc in Air at Atmospheric Pressure
L. M. Shpanin1, G. R. Jones2, J. W. Spencer2 1Electronic, Electrical and Computer Engineering,
University of Birmingham, Birmingham, United Kingdom
2Electrical Engineering and Electronics, University of Liverpool, Liverpool, United
Kingdom
An electromagnetically convoluted arc plasma column has previously been investigated for the interruption of high voltage Alternating Currents [1]. The convoluted arc column was formed around the outside of a magnetic field producing coil by the interaction of the arc sustaining current (several kilo-amperes) with the spatial distribution of the magnetic field. In this contribution investigations into a D.C., rather than A.C., form of a convoluted arc column in air at atmospheric pressure are described. It is shown that under such conditions, strong pulsations in the power dissipated in the convoluted arc occur without the extinction and re-ignition of the arc and their associated, severe voltage transients. The pulsations appear to be associated with the formation and collapse of the arc helix and are manifest as regular oscillations of the arc voltage. Results will be presented for the time variation of the arc electrical parameters, which reflect the power pulsations along with high-speed photographs, which give an insight into the causes of the pulsations. Consideration will be given to the possible use of such a device for producing plasma pulses for various applications. 1. L. M. Shpanin, G. R. Jones, J. W. Spencer, J. E. Humphries, Electromagnetic arc convolution and enhanced PTFE ablation for current interruption, Proc. 17th Int. Conf. on Gas Discharges and their Applications (ISBN 978-0-9558052-0-2), Cardiff, U.K., 2008, pp.133-136.
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O8-7: Advantages of Second-Generation High Temperature Superconductors for
Pulsed Power Applications J. C. Hernandez-Llambes, D. Hazelton
Superconducting Devices, Superpower-Inc, Schenectady, United States
Within the past few years a newer, more robust type of superconductor known as Second-generation (2G) High Temperature Superconductor (HTS) wire, has become available in sufficient quantities and lengths for developers to build prototype devices and test their capabilities. This new material offers the potential for revolutionary changes in magnet technology, enabling more compact and higher performance systems that can meet the stringent demands of different pulsed power technologies, particularly for those in high energy density, nuclear, fusion and plasma applications. This manuscript will discuss the latest advantages and superior performance of the new 2G HTS superconductors. We will discuss the principal advantages over First-Generation (1G) Low Temperature Superconductors (LTS) and conventional conductors. We also discuss how pulsed power applications can benefit from their use and their suitability. We will show a wide range of extreme low and high temperature tests performed with currents up to 40kA with 2G HTS that demonstrate superior performance and new capabilities. We also will illustrate different applications where 2G HTS can be the key to improving the performance, compactness and other capabilities of present pulsed power applications.
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O9: Intense Electron and Ion Beams and Plasmas
Colonial
Tuesday, June 30 13:00-14:30
O9-1: Generation of Ion Beams in Positive Polarity on HERMES III Operated
in a Long-Pulse Mode* T. J. Renk1, V. J. Harper-Slaboszewicz1,
K. A. Mikkelson1, J. W. Schumer2, P. F. Ottinger2 1Sandia National Laboratories, Albuquerque, NM,
United States 2Naval Research Laboratory, Washington DC,
United States
We report on ion diode experiments on the HERMES III facility [1] at Sandia National Laboratories. In negative polarity, HERMES design parameters are 20 MV, 700kA, 40 ns. Here, positive polarity operation is desired for ion beam extraction. However, in order to minimize conversion time from the normal negative polarity operation, the charging voltage was reversed rather than reversing the adder cavities. Voltage stresses on the insulators were reduced by operating the accelerator in the long pulse mode originally used in some radiographic studies [2]. This is the first time HERMES has been operated in full machine, positive polarity, long pulse mode, with nominal parameters of 8 MV, 300 kA, 90 ns. The ion beam is generated in a pinch-reflex ion diode [3]. Electrons are emitted from a cylindrically symmetric knife-edge cathode (6 cm radius), and initially cross the anode-cathode (A-K) gap directly. Increasing current within the diode diverts the electron orbits toward the center axis, where proximity to the thin-foil anode leads to ion evolution and extraction. Power flow into the ion diode from the HERMES multi-cell inductive adder section and magnetically insulated transmission line (MITL) was modeled using the LSP particle-in-cell code. In order to retain the physics of layered electron power flow with a moderate-amount of numerical effort, the 20-cell adder-section was modeled using a 5-cell equivalent, all the while using average inner-radii center conductor elements within the MITL. Ion-current efficiency scaling with voltage, cathode-radius, and AK-gap agreed with analytic estimates from previous self-pinched ion-diode experiments. Using an assumed HERMES forward-going wave, load currents were predicted for various A-K gaps. Ion generation efficiencies of 20% were predicted. Beam experiments have been conducted with diagnostics consisting of time-integrated shadowbox/witness plates, nuclear activation, and a Faraday cup array. Load voltage is inferred from the diagnostics package, and MITL currents are measured by monitors located on both anode and cathode side. Measurements to date indicate a mostly protonic beam of between 4 and 6 MV,
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depending upon the A-K gap, with consistency between the nuclear activation and Faraday cup diagnostics. Efforts are ongoing to optimize the beam power and understand the power flow from MITL section to the A-K gap, and latest results will be presented. *Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin Co., under US DOE Contract DE-AC04-94AL85000. [1] J. J. Ramirez, et al., HERMES III, A I6 TW, Short Pulse, Gamma Ray Simulator, in Proceedings of the 7th International Conference on High Power Particle Beams, (Karlsruhe, West Germany, July 4-7, 1988), p. 148. [2] M. G. Mazarakis, et al., in Proceedings 10th IEEE Pulsed Power Conference, (Albuquerque, NM, July 10-13, 1995), p. 528. [3] S.J. Stephanakis, et al., Phys. Rev. Lett. 37, 1543 (1976).
O9-2: High-Voltage, High-Impedance Ion Beam Production from Extended
Cylindrical Diodes D. Hinshelwood1, R. J. Allen1, R. J. Commisso1,
G. Cooperstein1, S. L. Jackson2, D. Mosher3, D. P. Murphy1, P. F. Ottinger1, J. W. Schumer1, S. B. Swanekamp3, B. V. Weber1, F. C. Young3 1Plasma Physics Division, US Naval Research
Laboratory, Washington, DC, USA 2National Research Council Postdoctoral
Research Associate, Washington, DC, USA 3L-3 Communications, Reston, VA, USA
We are pursuing the development of high-voltage (3-6 MV), relatively high-impedance (10-20 Ohms) pulsed ion diodes for DoD applications [1]. We have converted the 6-MV, 300-kA Mercury inductive-voltage adder [2, 3] to positive polarity to drive such diodes. In a conventional ion diode with a cylindrical cathode and axial gap, the diode current is limited to the critical current that scales with the ratio of radius to gap. The ion efficiency scales with the ratio of electron to ion path lengths in the diode, which in turn scales with the ratio of radius to gap. Therefore, the ion efficiency scales roughly inversely with the diode impedance, which reduces performance on higher-impedance generators. This limitation can be circumvented by arranging the electrodes as concentric cylinders with a radial gap [4-6]. In this case, the critical current is unchanged but the ion efficiency now scales with the ratio of cylinder length to gap. Thus, with a sufficiently long diode, high efficiency at high impedance should be possible. This so-called equatorial-pinch diode may also be thought of as an extended rod-pinch diode, where the high ion currents that can limit radiographic performance [7] are now viewed as an asset. While this geometry is not suitable for ion-beam transport, it is suitable for applications where the source size and/or directionality are not critical - in particular, the production of either neutrons, or characteristic gammas using the reaction 19F(p,alpha-gamma)16O. Indeed, the extended size of the source may facilitate survivable electrodes and thus a higher shot rate. We will present results of experiments with a variety of cylindrical diode geometries, as well as comparison with the results of LSP [8] simulations. Diagnostics include electrical monitors, depth-dose stacks, and a variety of activation measurements. 1. R.J. Commisso, these proceedings. 2. R.J. Allen, et al., “Initialization and Operation of Mercury, a 6-MV MIVA”, 15th IEEE Pulsed Power Conf., June 2005. 3. R.J. Allen, et al., these proceedings. 4. R.J. Barker and Shyke A. Goldstein, "Decoupling Ion Efficiency from Impedance in
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Pulsed Power Diodes," NRL Memorandum Report 5184 (1983). 5. G. Cooperstein, et al., "Status of Light Ion Inertial Fusion Research at NRL," Laser Interaction and Related Plasma Phenomena, 6, 957 (1984), and references therein. 6. J.N. Olsen, et al., "Self-Magnetic-Field-Enhanced Ion Diode," J. Appl. Phys 55, 1263 (1984). 7. B.V. Oliver, et al., "Magnetically insulated electron flow with ions with application to the rod-pinch diode," Phys. Plasmas 11, 3976 (2004). 8. ATK Mission Research, Albuquerque, NM 87110.
O9-3: Application of TW-Level Pulsed Power to the Detection of Fissile
Materials* R. J. Commisso1, J. W. Schumer1, F. C. Young2, J. P. Apruzese1, R. J. Allen1, G. Cooperstein1, D.
Hinshelwood1, S. L. Jackson3, D. Mosher2, D. P. Murphy1, P. F. Ottinger1,
S. B. Swanekamp2, S. J. Stephanakis2, B. V. Weber1
1Plasma Physics Division, Naval Research Laboratory, Washington DC, United States
2Titan Group, L-3 Communications, Reston, VA, United States
3NRL National Research Council Research Associate, Washington DC, United States
The remote detection of fissile material by passive and active techniques is an area of intense interest. Many active detection approaches using either photon or neutron irradiation are being investigated.[1] Pulsed-power generators, often applied to the laboratory simulation of nuclear weapon effects, can be an integral part of a methodology to detect fissile material Using various beam-target interactions, short-pulse (50- to 100-ns), high-power (1- to 9-MV, 10- to 1000-kA) accelerators are able to produce intense bursts of a variety of radiations including bremsstrahlung, characteristic gamma rays, and neutrons. These radiations can induce fission, the products of which may be detected. Success of this approach depends heavily on innovations in compact pulsed power and development of high-sensitivity, low signal-to-noise detection schemes. We will report on the production of 6.13-, 6.92-, and 7.13-MeV characteristic gamma rays from the 19F(p,alpha-gamma) reaction using a water-line generator at 2 MV/1.5-TW (Gamble II)[2,3] and an IVA at ~ 3.5 MV/~1 TW using a pinch-reflex ion diode[4]. For this work, Mercury was converted to run in positive polarity [5]. Issues regarding IVA operation in positive polarity [6] will also be discussed. *Work supported by DTRA and ONR [1] See manuscripts in Nucl. Instr. and Meth. in Phys. Res. B, vol. 261, pp. 268-378, 2007. [2] J.W. Schumer, R.J. Commisso, et al., in the Proceedings of the 2007 IEEE Nuclear Science Symposium and Medical Imaging Conference (Honolulu, HI, October 28 – November 3, 2007), p. 1026. [3] R.J. Commisso, J.W. Schumer, et al., presentation at the 9th International Conference on Applications of Nuclear Techniques, Rethymno, Crete, June 2008. [4] S.J. Stephanakis, et al., in Proceedings of the 9th Inter. Conference on High Power Particle Beams, Edited by D. Mosher and G. Cooperstein (NTIS, Springfield, VA, 1992) vol. II, p. 871. [5] R.J. Allen, this conference. [6] J.W. Schumer, et al., this conference.
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O9-4: Design of a Compact Coaxial Magnetized Plasma Gun for Magnetic
Bubble Expansion Experiments Y. Zhang1, A. G. Lynn1, S. C. Hsu2, H. Li2,
W. Liu2, M. Gilmore1, C. Watts1 1University of New Mexico, Electrical & Computer
Engineering Department, Albuquerque, NM, United States
2Los Alamos National Laboratory, Los Alamos, NM, United States
This talk will discuss the design of a compact coaxial magnetized plasma gun and its associated hardware systems in detail. The plasma gun is used for experimental studies of magnetic bubble expansion into a lower pressure background plasma as a model for extragalactic radio lobes. The gun is powered by a 120F, 10kV ignitron-switched capacitor bank. High-pressure gas is puffed into an annular gap between inner and outer coaxial electrodes. The applied high voltage ionizes the gas and creates a radial current sheet. The ~100kA discharge current generates toroidal flux; and poloidal flux is provided by using an external bias magnet. The axial JB force ejects plasma out of the gun. If the JB force exceeds the magnetic tension of the poloidal flux by a sufficient amount then a detached magnetized plasma will be formed. Using spatially resolved magnetic probe array measurements and a high speed camera, we are studying the evolution of this plasma bubble as it interacts with a pre-existing lower pressure background plasma which is provided by a helicon source (HelCat). The talk will discuss details of the plasma bubble formation system including the main-bank power system, gas valve control system, bias flux power system, and the magnetic probe diagnostic. Experimental data will also be provided. Supported by NSF-AST/DOE grant AST-0613577 and LANL LDRD
O9-5: LIF Characterization of the Hollow Anode Plasma Ions
V. Vekselman, D. Yarmolich, J. Gleizer, J. Felsteiner, Y. E.Krasik
Physics department, Technion, Haifa 32000, Israel
Measurements of plasma ion velocity distribution during operation of the high-current (1 kA, 20 us) Hollow Anode (HA) electron source with and without application of the accelerating pulse (200 kV, 200 ns) were carried out using Laser Induced Fluorescence (LIF) technique. The application of a single-frequency dye laser with narrow bandwidth and ns-timescale pulse duration provides time- and space-resolved accurate non-perturbing measurements of ion energy distribution which were not available using other electrical or spectroscopy measurements. The data obtained in current research suggesting possible explanation of electron extraction from the boundary of the positively charged plasma during the HA operation for reliable and reproducible generation of electron beams ~ 1 kA with cross-sectional area of up to 200 cm^2.
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O9-6: Supershort Avalanche Electron Beam Generation in Gases
V. F. Tarasenko High Current Electronics Institute, Tomsk,
Russian Federation
This paper reports the properties of supershort avalanche electron beam (SAEB) formed in different gases under atmospheric pressure and analyses the SAEB generation mechanism and methods of its registration. It is shown that at a nanosecond discharge in the atmospheric pressure air and SAEB current recording through a small diameter area the pulse duration behind the foil is not larger than 80 ps. In order to record the pulse shape, it is necessary to use a small-size coaxial collector loaded to a high-frequency cable and to read a charge density distribution over the foil surface for determining the SAEB amplitude by means of this collector. The obtained electron distribution over the foil section should be compared with the distribution obtained per pulse by means of a luminescent screen or a photographic film. It is demonstrated that SAEB is generated into an angle exceeding 2π sr in the air at the pressure of 1 atm. Decrease of the gap d between the cathode and anode results in the amplitude decrease of the beam current generated to the side walls of the gas diode. However, even at small discharge gap (d=8 mm) the beam current is generated in direction of the gas diode side walls placed at a certain distance from the cathode that exceeds several times the value of the discharge gap. Generation of the electron beam into the solid angle exceeding 2π sr is explained by the fact that at SAEB generation the dense plasma near the cathode has the form close to the spherical one. An electron beam was obtained behind AlBe foil of the thickness 45 μm at the pressure of sulfur hexafluoride and xenon in a gas diode up to 2 atm and at the pressure of helium up to 15 atm. It was demonstrated that FWHM of a supershort avalanche electron beam increases up to 150 ps at the increased pressures of sulfur hexafluoride (>1 atm).
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O10: Pulsed Power Switches and Components – Closing Switches
Ballroom
Tuesday, June 30 13:00-14:30
O10-1: Jitter and Recovery Rate of a Triggered Spark Gap with High Pressure
Gas Mixtures Y.J. Chen, J. Dickens, J. Walter, M. Kristiansen
EE, Texas Tech University, Lubbock, United States
Recent attention in impulse antenna phased array has necessitated the need to develop a reliable high voltage, high repetition rate switch that will operate with ultra low jitter. An ideal jitter of a small fraction of the rise time is required to accurately synchronize the array to steer and preserve the rise time of the radiated pulse. This paper presents the impact, gases and gas mixtures have on switch performance which includes recovery rate and in particular, jitter. A 50 Ω, ~1 nF pulse forming line is charged to 50 kV and provides the low inductance voltage source for testing. Triggering is provided by an SOS voltage source that supplies 80 - 150 kV, 10 ns rise-time pulses at a rep rate up to 100 Hz in burst mode. A hermetically sealed spark gap with a Kel-F lining is used to house the switch and high pressure gas. Gases tested include, dry Air, H2, N2, and SF6, as well as various mixtures such as H2-N2 and N2-SF6. A Kr85-Ar gas mixture is also tested in a N2 environment to further improve switch jitter. Switch gas temperature as a function of operation time with resulting jitter measurements is quantified. Manipulation of switch gas temperature and its effects on jitter will also be discussed.
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O10-2: Low Inductance Switching Studies for Linear Transformer Drivers W. A. Stygar1, L. F. Bennett1, H. D. Anderson2,
J. R. Woodworth1, J. A. Alexander1, M. J. Harden2, J. R. Blickem3, F. R. Gruner4,
R. White5 1Dept 1671, Sandia National Laboratories, Albuquerque, New Mexico, United States
2National Security Technologies, Albuquerque, New Mexico, United States
3Ktech Corporation, Albuquerque, New Mexico, United States
4Kinetech LLC, The Dalles, Oregon, United States
5L3 Communications, Pulse Sciences, San Diego, California, United States
We are developing new low-inductance gas switches for Linear Transformer Drivers (LTDs). Linear Transformer drivers are a new pulsed-power architecture that may dramatically reduce the size and cost of future pulsed-power drivers, but which place stringent requirements on gas switches. A typical large LTD may have 10,000 or more gas switches that are DC-charged to 200 kV and that must be triggered with a jitter of 5-ns or less with a very low prefire rate. We are studying new air-insulated gas switches with total inductances of 70-90 nH. These switches transfer 100 J of stored energy for thousands of shots. Typical 10%-90% current risetimes are less than 50 ns and peak currents are on the order of 40 kA into a matched load. One of the switches has a 1-sigma jitter less than 800 picoseconds. Since triggering 10,000 or more switches is a significant challenge, we are also making a detailed study triggering requirements for these switches. Details of switch geometries, triggering, performance, and lifetimes will be presented. Sandia is a multiprogram laboratory operated by Sandia Corporation for the United States Department of Energys National Nuclear Security Administration under Contract DE-AC04-94AL85000.
O10-3: High Voltage, Flowing Fluid Switch
S. Heidger1, M. Ruebish2, R. D. Curry3, D. Shiffler1
1Air Force Research Laboratory, Kirtland AFB, NM, United States
2Sandia National Laboratories, Albuquerque, NM, United States
3University of Missouri-Columbia, Columbia, MO, United States
The self break performance of a high pressure, flowing oil, repetitive output switch integrated into a primary transformer-pulse forming network test pulser with impedance of 5 ohms that is capable of 250 kV output voltage, 50 nanosecond pulse length and repetition rates of 30 pulses per second is investigated. In particular, we study switch performance (jitter at optimal efficiency - breakdown at 80-90% of full charge) as a function of the fluid flow rate, switch pressure and balance of fluid flow through the radial and axial sections of the switch. Data shows initial assumptions that the switch needed to operate above the critical pressure for suppression of bubble formation in the PAO (326 psi) proved incorrect. Current data suggests that the jitter is lower at pressures below the critical pressure of bubble formation as long as a proper balance of axial and radial flow and sufficient flow rates to sweep debris and whatever bubbles are formed is maintained. These lower pressure requirements mean the switch can be designed with a thinner and lighter housing than the current 2000 psi rated version, and a much smaller, fluid pumping system. The switch is at least 4X more compact, than gas filled switches capable of comparable operation and utilize flight qualified, poly alpha olefin dielectric coolant that is resident in most airframes.
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O10-4: Repetitively Pulsed 1 MV Laser Triggered Gas Switches
F. Hegeler1, J. D. Sethian2, M. C. Myers2, A. M. Fielding1, M. F. Wolford2, R. L. Jaynes3,
P. M. Burns4, J. L. Giuliani2, M. Friedman1 1Commonwealth Technology, Inc., Alexandria,
VA, United States 2Plasma Physics Division, Naval Research Laboratory, Washington, DC, United States 3Science Applications International, Corp.,
McLean, VA, United States 4Research Support Instruments, Lanham, MD,
United States
The krypton fluoride (KrF) laser facility, Electra, is a repetitively pulsed, electron beam pumped laser system at the Naval Research Laboratory, which is focused on meeting the scientific and technical requirements of a durable driver for Inertial Fusion Energy (IFE). The main laser amplifier includes two identical pulsed power systems that generate 500 kV, 100 kA, 140 ns pulses to opposing diodes. Each pulsed power system charges two parallel pulse forming lines (PFL) to 1 MV, and the energy is switched into the electron beam diode load with laser triggered spark gaps at the end of each line. The two parallel, sulfur-hexafluoride filled spark gaps should fire within a few nsec in order to apply the correct power pulse to the cathode. This in turn requires low jitter and by inference, relatively short runtimes. The switches must maintain this performance at repetition rates of up to 5 Hz for more than 100,000 continuous pulses without maintenance. The original switches employed a hemispheric electrode shape that created highly non-uniform electric fields across the gap and caused the middle of the gap to operate at greater than 50% above self-break. This design could not meet the jitter requirements for runs exceeding a few thousand shots. In addition, erosion as well as fogging of the trigger optics limited operation to 30,000 shots. A new electrode shape has been successfully implemented in the 1 MV, 50 kA spark gaps that significantly improves the switch performance and increases electrode life. It uses flat electrodes with a diameter of 37 mm to produce a more uniform electric field in the switch gap. A similar concept was introduced by LeChien et al. for the ZR switch [1], and it has been modified to fit the repetitive application for the Electra KrF laser. This paper compares the original and new electrode shapes of the 1 MV laser triggered spark gaps and discusses the switch jitter, runtime, trigger laser energy, electrode erosion, and the trigger optic shot life. [1] K. R. LeChien et al., "Development of a 5.4 MV laser triggered gas switch for multimodule, multimegampere pulsed power drivers," Physical
Review Special Topics-Accelerators and Beams, vol. 11, article number 060402, June 2008. Work is supported by DOE/NNSA
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O10-5: Evaluation of Spark Gap Switches Operated at Low Percent of Self Break
Voltage J. M. Lehr1, K. C. Hodge2, S. F. Glover1,
G. E. Pena2, L. X. Schneider2 1Exploratory Pulsed Power, Sandia National
Laboratories, Albuquerque, NM, United States 2Ktech Corporation, Albuquerque, NM, United
States
GENESIS is a low impedance driver, capable of precision current pulse shaping up to 4 MA with programmed, variable risetimes between 200 and 600 ns. GENESIS’ programmable pulsed power requires variable, precision current-pulse shaping, achieved through the sequential triggering of 240 switches, with unprecedented high voltage switch operating range requirements. Programmability is achieved by varying the relative trigger times of specific sets of switches. During the charge cycle, the GENESIS switches must hold off the full 200 kV charge voltage. However, as some switches are triggered, the relative voltage across the remaining switches begins to decrease while they await their trigger for the desired pulse shaping. The relative voltage across these second and third tier switches may decrease to as low as 100kV. These switches have to operate reliably at these lower voltages with a gas pressure set for full voltage hold off. In addition to the specific GENESIS application, this evaluation is also pertinent to crowbar or diverter switches, were the switch must initially hold off much higher voltages than it will be triggered at.
O10-6: Prospective Pulsed Power Applications of Pseudospark Switches
J. Slough1, C. Pihl1, V. D. Bochkov2, D. V. Bochkov2, P. V. Panov2, I. N. Gnedin2 1Plasma Dynamics Laboratory, University of
Washington, Redmond, WA, USA 2Pulsed Technologies Ltd., Ryazan, Russian
Federation
The evolution of pulsed power technologies is closely associated with development of high-power and fast switching components. Pseudo Spark Switches (PSS) or thyratrons of TPI- and TDI-type are known as promising [1, 2] switching elements. The range of pulsed power technologies in which these thyratrons can be applied is very wide. The most prominent applications are apparatuses for new energy sources (including thermonuclear fusion), environment-friendly, energy-saving and robotic production installations for material processing. The TDI-type switch is successfully tested in installations of "plasma focus", plasma lens, in shock waves sources, used for materials processing, medical lithotripters, crowbar protection circuits etc. TDI and TPI-switches are free of a majority of shortcomings inherent in conventional thyratrons, in particular TDI-thyratrons equipped with built-in device designated as SRNV are capable of operating in completely no-heating regime, that is without heating both of cathode and hydrogen reservoir [2]. In this report some results of comparative tests for PSS TDI1-150/25-models versus mercury ignitrons type D switches in Field Reversed Configuration (FRC) installations with energy storage up to 14kJ, operating voltage 5-40 kV, peak currents Imax =190 kA, jitter 4-10 ns are presented. Another application, connected with an idea of 1950-s to process various materials by electric discharge in a liquid-filled bath has recently emerged due to increasing cost of materials and energy, strict requirements to environmental safety. The data on tests of electro-hydropulse installation module with energy storage up to 3 kJ for operation with large volumes of processed materials (up to several tons per hour) are presented. The choice of TDI switch has been motivated by the fact that it combines all advantages of modern fast switches such as low stored energy losses, low jitter, absence of heated cathode, high durability and resistance to failure, containing no mercury, high radiation tolerance, low overall dimension and low cost. Tests have shown that TDI-thyratrons are characterized as stable and reliable switches for high currents (over 25 kA). Self inductance of the thyratrons is considerably less than for existing
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switching components and is estimated to be less 8 nano Henry, allowing for efficient energy transfer to low impedance loads. The switches are capable of withstanding high overcurrents up to 200 kA, rate of current rise up to 5x10^12 A/s at oscillation frequency in burst mode. Based on the life tests data for the most powerful TDI-thyratrons the recommendations serving to simplify the choice of the best switch for installations reliability improvement are presented. The TDI-thyratrons do have doubtless advantages if compared with ignitrons, hot cathode thyratrons, triggered spark-gaps, vacuum gaps and solid-state components and are recommended as the best switching elements in pulsed power installation. [1] Journal of Physics D: Appl. Phys. 37 (2004) 2107–2111. [2] 2nd Euro-Asian Pulsed Power Conference, Vilnius, Lithuania, Sept. 2008, O4-5.
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O11: Pulsed Power Switches and Components – Solid State Switches
Ballroom
Tuesday, June 30 15:00-17:00
O11-1: Wide-Pulse Evaluation of 0.5 cm2 Silicon Carbide SGTO
H. K. O’Brien1, A. Ogunniyi1, W. Shaheen2, C. Scozzie1, A. K.Agarwal3, V. Temple4
1US Army Research Laboratory, Adelphi, MD, United States
2Berkeley Research Associates, Beltsville, MD, United States
3Cree, Inc, Durham, NC, United States 4Silicon Power Corporation, Clifton Park, NY,
United States
Silicon carbide Super-GTOs are being pursued by the Army as a replacement for current silicon-based, high-power pulse switches. In the Army Research Laboratorys evaluations, silicon carbide has shown wide-pulse (1-ms width) current capabilities with a factor of 1.5 times higher current and 2.5 times higher action compared to similar silicon devices. As material development improves, silicon carbide SGTOs of larger area and higher hold-off voltage are being fabricated at reasonable wafer yield levels. The SGTOs evaluated in this study are four times the area of the last generation of SiC SGTOs and have about double the voltage blocking. They were developed in collaboration with Silicon Power Corporation and Cree, Inc. The SGTOs are designed for 5-7 kV high-voltage blocking and 100 V reverse-gate blocking. The active (emitter) area for each device is 0.36 cm2, about 70% of the device area. The devices included in this study were all fabricated by Cree and packaged in-house at the Army Research Laboratory. The 0.5 cm2 silicon carbide SGTOs were evaluated in an RLC pulse circuit which provided a half-sine shaped pulse at a width of 1 ms. The parameters assessed were peak current capability, 1000-shot reliability, and current sharing between parallel switches. SGTOs were pulsed as high as 1550 A, but 1250 A was found to be the most reliable and repeatable current level for most devices. This current waveform corresponds to an action of 820 A2s and a current density over the emitter area of 3.5 kA/cm2. Additional evaluations were conducted with two SGTOs connected in parallel. Together, they were pulsed up to 2600 A, and repeatedly at 2500 A, with current sharing of 51% and 49%. The pair of devices was pulsed for over 1000 single shots without any significant change in forward voltage drop or current sharing. This paper details the evaluations of individual and paralleled devices which are being studied in preparation for future work with multi-chip modules.
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O11-2: 8 kV, 8mm X 8mm SiC SUPER GTO Technology Development for Pulse
Power A. K. Agarwal1, C. Capell1, J. Zhang1, R. Callanan1, J. Melcher1, V. Temple2,
H. K.O’Brien3, C. Scozzie3 1SiC Power Device R&D, Cree Inc., Durham, NC,
United States 2Commercial Power Division, Silicon Power Corporation, Clifton Park, NY, United States 3AMSRD-ARL-SE-DP, U.S. Army Research
Laboratory, Adelphi, MD, United States
The SiC Super GTO devices are being developed by Cree jointly with Army Research Laboratory and Silicon Power Corporation for pulse power applications. During the last 5 years, the SiC materials technology has made rapid advances in reducing substrate and epilayer defects, improving minority carrier lifetime and increasing wafer diameter from 75 mm to 100 mm. Along with materials improvements, substantial advances in fabrication technology and device optimization including edge termination have led to 8 kV, 8 mm x 8 mm SiC Super GTO devices which have been packaged in the Thin Pak configuration with no wire bonds to achieve a pulsed current density of 4 kA/cm2 normalized to the active area, stable forward voltage drop, high action and short Tq recovery times. The devices show extremely low leakage current of about 100 nA up to 8 kV and a sharp avalanche at 8.5 kV. Current sharing is very important when a large number of smaller devices are packaged together. It will be shown that the SiC super GTOs share the current well under dynamic operation and therefore this is a viable technology for pulse power applications. It may not be necessary to go to full wafer SiC devices which will take a very long time to mature. Currently, 10 kV, 1 cm2 die are being fabricated. This paper will address the advances in SiC materials, device design, processing and yield of large area devices. We believe that SiC Super GTO technology is poised to make a major impact on a wide variety of short and long pulse applications for DoD systems such as Rail Guns and Active Armor.
O11-3: SiC Based High Voltage Switches - Options in Pulse Power
P. Friedrichs SiCED Electronics Development GmbH & Co.
KG, Erlangen, Germany
A certain attention paid to wide band gap semiconductors was observed beginning in the early nineties. Regarding power devices, it was focused during the last years to the most interesting materials like GaN and SiC. Especially SiC has realized an impressive growth process due to its outstanding technological advantages. In contrast to the most other candidates among the wide band gap semiconductors SiC can be characterized by the following advantages • Indirect semiconductor, important for bipolar power electronics e.g. • Ability for selective doping of both, n- and p-type • Native thermal oxide SiO2 • Freestanding and high quality crystals available • Broad targeted range of applications (power electronics, high frequency electronics optoelectronics, high temperature electronics etc.) After only ten years from first attempts to grow device grade substrates, the introduction of first products (Schottky Barrier diodes) occurred in 2001 by Infineon and Cree. Even considering the higher device price, the implementation in systems could be realized also from an economical point of view due to the achievable system advantages. The use of SiC components is today mainly triggered by the possibility to achieve higher power densities for power conversion systems via higher switching frequencies. Next steps will be characterized by a broader spectrum of blocking voltages as well as an improved cost-performance ratio for addressing additional potential applications. The development of SiC based switching devices is still at R&D level for MOSFET type structures, however, vertical JFETs are in a mature phase and nearly ready to be fabricated. Scenarios exist how to implement these devices successfully in emerging markets for highly efficient energy conversion like photovoltaic systems. A more sustaining development is mandatory in order to exploit the performance of SiC in the high voltage market. Even if technically attractive solutions are available, for instance in distributed energy components or for new generation traction systems, the technical and economical breakthrough cannot be fixed on a time scale based from a today’s point of view. However, we will demonstrate some results which prove the huge technical advantages which can be gained from using SiC. New applications can come up which up to know were not imaginable with the abilities of existing power semiconductors. One of thee scenarios could also be the use in pulse
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power applications. For these applications mainly the ability of SiC to offer high blocking voltages even for unipolar devices and thus, very fast switching is of interest. It will be sketched like e.g. by a simple serial connection several tens of kV blocking with switching times in the ns range can be achieved. The presentation should give the community an inside in the potential and the status of SiC semiconductors with special respect to the needs in pulse power systems.
O11-4: Device Optimization and Performance of 3.5 cm^2 Silicon SGTO for
Army Applications A. Ogunniyi1, H. K. O'Brien1, C. Scozzie1,
W. Shaheen2, V. Temple3 1US Army Research Laboratory, Adelphi, MD,
United States 2Berkeley Research Associate, Beltsville, MD,
United States 3Silicon Power Corporation, Clifton Park, NY,
United States
The U.S. Army Research Laboratory (ARL) has been investigating silicon super gate turn-off thyristors (SGTOs) for high action pulse switching necessary for Army survivability and lethality applications. The silicon SGTO designed by Silicon Power Corporation (SPCO) was evaluated to determine its repeatable pulse current capability at a 1 ms pulse width. The initial SGTO design was a 3.5 cm^2 chip rated for 4 kV forward blocking and 10 kA peak current at 10 μs pulse width or 100 A continuous. When High pot tested, most of the Si SGTOs exhibited hold off voltage beyond 4 kV. The majority of the Si SGTOs blocked up to 7 kV while displaying a leakage current of 100 μA. The active (cathode mesa) area of the device was 2.0 cm^2. The minimum recommended gate pulse required to turn on the device ranges from .5 A to 1 A. Rapid turn-on and even current distribution across the device area was achieved because of the cell based emitter design and the integrated gate and cathode fingers. The entire Si SGTO die used in this work was packaged by SPCO. SPCO used a ThinPak lid and high voltage potting compound to package the SGTOs. The ThinPak lid eliminates wire bonds and reduces parasitics such as stray inductance and bond resistance. The previous work by ARL on these switches reported repetitive peak current of 5 kA with a charge voltage of 4 kV. Additionally, the switches failed short at peak currents of 6 kA, with calculated action of 1.3 x 10^4 A^2 s at 5 kA. This work highlights the device optimization that SPCO has since made on the Si SGTO to improve the device pulsing performance. The latest Si SGTO evaluated maintains the same chip area and active area as the previous devices. Modification to the packaging design and the enhancement of the emitter design enables the latest Si SGTO to exhibit repeatable peak current of 5.5 kA (a 10% increase compared to the previous batch). Furthermore, these devices can handle single-shot currents well over 6 kA before failure. The calculated action for the latest switches was 1.6 x 10^4 A^2 s at 5.5 kA. Additionally, a study was conducted on the effects of varying gate current on the device forward voltage drop at 1 ms. It can be noted that the gate amplitude and width do not
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affect the Si SGTO voltage forward drop at 1 ms pulse width.
O11-5: Analysis of Ultra-Fast Switching Dynamics in a Hybrid MOSFET/Driver
T. Tang, C. Burkhart Power Conversion Department, Stanford Linear Accelerator Center, Menlo Park, United States
The turn-on dynamics of a power MOSFET during ultra-fast, ~ ns, switching are described in this paper. The testing was performed on a custom hybrid MOSFET/Driver module, which was fabricated by directly assembling die-form components, power MOSFET and drivers, on a printed circuit board. By using die-form components, the hybrid approach substantially reduces parasitic inductance, which facilitates ultra-fast switching. The measured turn on time of the hybrid module with a resistive load is 1.2 ns for an applied voltage of 1000 V and drain current of 33 A. Detailed analysis of switching waveforms reveals that common assumptions regarding switching behavior are not valid in the ultra-fast regime. For example, turn on of the hybrid module is effectively complete with <40% of the Miller charge injected into the gate. Further, analysis and simulation shows the minimum turn on time scales with the RC product of the drain-source on resistance and drain-source capacitance. This information will be useful in power MOSFET selection and gate driver design for ultra-fast switching applications.
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O11-6: Characterization of Power IGBTs under Pulsed Power Conditions
J. A. VanGordon1, S. D. Kovaleski1, G. E. Dale2 1Electrical and Computer Engineering, University
of Missouri, Columbia, MO, United States 2High Power Electrodynamics Group, Los Alamos
National Laboratory, Los Alamos, NM, United States
The power insulated gate bipolar transistor (IGBT) is used in many types of applications. Although the use of the power IGBT has been well characterized for many continuous operation power electronics applications, little published information is available regarding the performance of a given IGBT under pulsed power conditions. Additionally, component libraries in circuit simulation software packages have a finite number of IGBTs. This paper presents a process for characterizing the performance of a given power IGBT under pulsed power conditions. Specifically, signals up to 4.5 kV and 1 kA with approximately a 5 μs pulse width will be applied to a given IGBT. This process utilizes curve fitting techniques with collected data to determine values for a set of modeling parameters. These parameters are used in the Oziemkiewicz implementation of the Hefner model for the IGBT that is utilized in some circuit simulation software packages [1, 2]. After the nominal parameter values are determined, they can be inserted into the Oziemkiewicz implementation to simulate a given IGBT. [1] G.T. Oziemkiewicz, Implementation and Development of the NIST IGBT model in a SPICE-base commercial circuit simulator, Degree of Engineer Thesis, University of Florida, Gainesville, FL, USA, 1995. [2] Spectrum Software, Micro-Cap Version 9.0.2.0, 2007. This project is supported by Los Alamos National Laboratory.
O11-7: High Voltage Photoconductive Switches Using Semi-Insulating,
Vanadium Doped 6H-SiC C. James, C. Hettler, J. Dickens
Center for Pulsed Power and Power Electronics, Texas Tech University, Lubbock, TX, United
States
SiC manufacturers are continually improving the purity of their wafers, however, interband impurities, while detrimental in many applications, can be useful in the operation of photoconductive switches. Compact, high-voltage photoconductive switches were fabricated using c-plane; Vanadium doped 6H-SiC obtained from II-VI, Inc. This material incorporates a large amount of interband impurities that are compensated by the Vanadium amphoteric, but at present is only available as c-plane wafers. In order to avoid micropipe defects, lateral switches were fabricated to allow validation of material simulations. High quality epi-layers were grown on opposing faces to produce very low resistivity contacts on the semi-insulating material and high-k encapsulant increases the surface flashover potential of the switch. Spectroscopic analysis of the SiC and epi-layers was performed via photo-luminescent spectroscopy and electron spectroscopy. Switch parameters were simulated using Silvaco.
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O11-8: High-Power Picosecond Current Switching by Silicon Diode Using
Tunneling-Assisted Impact Ionization Front
S. N. Rukin, S. K. Lyubutin, B. G. Slovikovsky, S. N. Tsyranov
Ural Division, Institute of Electrophysics Russian Academy of Sciences, Ekaterinburg, Russian
Federation
New principle of high-power ultrafast current switching based on tunneling-assisted impact ionization front in silicon diode structures has been experimentally implemented and theoretically studied. A voltage pulse with amplitude of 180 kV and a front duration of 400 ps was applied to a semiconductor device containing 44 series connected silicon diode structures located in a 50-Ohm transmission line. Due to sharp nonuniformity of the applied voltage distribution across the length of the device the switching process presents a successive breakdown of the series connected structures. Each successive structure breaks down with a shorter time interval as the electromagnetic shockwave builds. The current switching by the individual structure takes around 30 to 50 ps, and is initiated at electric field of about 1 MV/cm in the vicinity of the p-n junction, where tunneling ionization of the silicon begins. At such conditions the rise time of the output voltage wave is determined by the switching time and inductance of a few last structures and can be less than 100 ps to a peak voltage over 100 kV. In experiments in 50-Ohm transmission line we have obtained 150-kV output pulses having 80 to 100 ps rise time. The maximum current and voltage rise rates are record for semiconductor switches and amount to 30 kA/ns and 1.5 MV/ns, respectively.
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O12: Explosive Pulsed Power 2 Colonial
Tuesday, June 30 15:00-17:00
O12-1: Stand-Alone, FCG-Driven High Power Microwave System
A. Young1, M. Elsayed1, J. Walter1, A. Neuber1, J. Dickens1, M. Kristiansen1, L. Altgilbers2
1Center for Pulsed Power and Power Electronics, Texas Tech University, Lubbock, TX, United
States 2SMDC, U.S. Army, Huntsville, AL, United States
An explosively driven High Power Microwave (HPM) source has been developed which is based on the use of a Flux Compression Generator (FCG) as the primary driver. Four main components comprise the HPM system, and include a capacitor-based seed energy source, a dual-staged FCG, a power conditioning unit and an HPM diode (reflex-triode vircator). Volume constraints dictate that the entire system must fit within a tube having a 15 cm diameter, and a length no longer than 1.5 m. Additional design restrictions call for the entire system to be stand-alone (free from any external power sources). An initial prototype of the system was fabricated, where FCG output currents of ~45 kA were transformed into voltages of ~140 kV, resulting in microwave radiation with power levels up to 30 MW. The prototype system also relied on outlet power for operation of the microwave diode vacuum system as well as an external detonator trigger device. Presented here are the details of improvements made to the first prototype, which includes elimination of all external power sources and decreasing the volume of the entire system (below 26 liters), while simultaneously increasing the output energy from the individual stages. As will be seen, the modifications made to the system components resulted in the radiation of microwaves with higher power levels than previously achieved. Waveforms will be shown which illustrate the development of power as it commutates through each stage of the system, as well as power radiated from the diode. Comparisons between the first prototype and the present design will be made, and data will be offered demonstrating the advantages of explosive pulsed power over traditional methods of HPM generation.
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O12-2: Integration of a Self-Contained Compact Seed Source and Trigger Set
for Flux Compression Generators M. Elsayed1, A. Neuber1, M. Kristiansen1, L.
Altgilbers2 1The Center for Pulsed Power and Power
Electronics, Texas Tech University, Lubbock, Texas, United States
2SMDC, U.S. Army, Huntsville, Alabama, United States
Implementing helical flux compression generators (HFCG) in a single-use and portable compact pulsed power application requires that all of the components including the FCG and its peripherals be minimized in size (more stress on volume than mass). Two integral components that accompany an FCG in this type of system is the prime power source and the trigger set. The objective of the prime power source or seed source is to provide the initial seed current/energy into the primary stage of an FCG. That is, the seed source will energize the FCGs field coil, thus indirectly providing flux to the energy amplifying working coil. This is known as indirect seeding. Another integral component in an FCG based pulsed power system is the trigger set. The trigger set is used to detonate an exploding bridge wire (EBW) which triggers the high explosives (HEs) in an FCG. The HEs are packed inside of an aluminum armature centered inside of the FCG coil. It is important that the trigger set be initiated at the time of maximum seed current magnitude into the primary stage of the FCG coil. This paper will discuss a recent design of a stand-alone apparatus that implements a self-contained (battery powered with full charge time less than 40 sec) [1], singleuse Compact Seed Source (CSS) using solid state components for the switching scheme along with a single-use Compact Trigger Set (CTS) that also implements a similar switching technique. The CSS and CTS stand-alone apparatus developed is a system (0.005-m3 volume and weighing 3.9 kg) capable of delivering over 360-J (~12 kA) into a 5.20-H FCG load and approximately 2-mJ (~600 A) into the EBW. Both the CSS and CTS have trigger energies of micro-Joules at the TTL triggering level. [1] M. Elsayed, M. Kristiansen, A. Neuber, Fast-charging compact seed source for magnetic flux compression generators, 2008 Review of Scientific Instruments. Vol. 79, 124702.
O12-3: A New 40 MA Ranchero Explosive Pulsed Power System
J. H. Goforth, W. L. Atchison, S. A. Colgate, J. R. Griego, J. A. Guzik, D. H. Herrera,
D. B. Holtkamp, G. Idzorek, A. Kaul, R. C. Kirkpatrick, R. T. Menikoff, H. Oona,
P. T. Reardon, R. E. Reinovsky, C. L. Rousculp, A. G. Sgro, L. J. Tabaka, T. E. Tierney,
D. T. Torres, R. G. Watt Los Alamos National Laboratory, Los Alamos,
NM, United States
We are developing a new high explosive pulsed power (HEPP) system based on the 1.4 m long Ranchero generator which was developed in 1999 for driving solid density z-pinch loads. The new application requires approximately 40 MA to implode similar liners, but the liners cannot tolerate the 65µs, 4 MA current pulse associated with delivering the initial magnetic flux to the 200 nH generator. To circumvent this problem, we have designed a system with an internal start switch and four explosively formed fuse (EFF) opening switches. The internal start switch is installed between the output glide plane and the armature. It functions in the same manner as a standard input crowbar switch when armature motion begins, but initially isolates the load. The circuit is completed during the flux loading phase using post hole convolutes. Each convolute attaches the inner (coaxial) output transmission line to the outside of the outer coax through a penetration of the outer coaxial line. The attachment is made with the conductor of an EFF at each location. The EFFs conduct one MA each, and are actuated just after the internal start switch connects to the load. EFFs operating at these parameters have been tested in the past. The post hole convolutes must withstand 80 kV at peak dI/dt during the Ranchero load current pulse. We describe the design of this new HEPP system in detail, and give the experimental results available at conference time.
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O12-4: Dominant Role of the Explosively Expanding Armature on the Initiation of
Electric Discharge in Magnetic Flux Compression Generators
S. I. Shkuratov1, J. Baird1, E. F. Talantsev2, L. Altgilbers3, A. H. Stults4
1Loki Incorporated, Rolla, MO, United States 2Pulsed Power LLC, Lubbock, TX, United States
3U.S. Army Space and Missile Defense Command, Huntsville, AL, United States
4U.S. Army Aviation Research, Development and Engineering Center, Huntsville, AL, United States
Energy losses during explosive and electrical operation of magnetic flux compression generators (FCGs) are not fully understood phenomena. Electric discharge within the FCG is one of the energy losses mechanisms in the system. In this paper, we experimentally demonstrate that the explosively expanding armature of the FCG plays a dominant role in the formation of plasma and electric discharge initiation inside the FCG.
O12-5: Experimental Results using Ferromagnetic Generators to Load
Inductive Coils
A. H. Stults Aviation and Missile Research, Development,
and Engineering Center RDMR-WDF-S
Several experimental series of using explosively loaded ferromagnetic generators into inductive coils have been summarized into a lessons learned outline of best practices for building small FMGs. All of these FMGs were built using 25mm diameter, commercially available N50 magnets. All of these experiments were conducted at Redstone Arsenal, AL. Loads representative of flux compression stators were built and used but long time, tens of microseconds, effects on the inductors were also examined. This paper will summarize over seventy tests with techniques used to mitigate skin losses as well as eddy current losses. Improved energy density over prior efforts is explained. First cut scaling by linear combination of generators is also shown. References Shkuratov, S.I., Talantsev, E.F., Baird, J., Altgilbers, L.L., Stults, A.H., and Kolossenok, S.V. “Operation of High-Voltage Transverse Shock Wave Ferromagnetic Generator in the Open Circuit and Charging Modes”, 2005 IEEE Pulsed Power Conference, pp. 533-536.
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O12-6: Conductivity of Explosively Shocked Polycrystalline and Single
Crystal Potassium Chloride S. I. Shkuratov1, J. Baird1, E. F. Talantsev2, L.
Altgilbers3, A. H. Stults4 1Loki Incorporated, Rolla, MO, United States
2Pulsed Power LLC, Lubbock, TX, United States 3U.S. Army Space and Missile Defense Command, Huntsville, AL, United States 4Development and Engineering Center,
Huntsville, AL, United States
The search for dielectric materials that are capable of changing their conductivities due to the shock compression is important for the development of miniature magnetic flux compression generators. Results of experimental investigations into changes in the electrical conductivity of explosively shocked polycrystalline and single crystal potassium chloride samples are presented. KCl polycrystalline samples of diameter D = 32.5 mm/thickness h = 13 mm and single crystals oriented in (100) direction of D = 38.0 mm/h = 6 mm were loaded by shock waves generated from high explosives (desensitized RDX). It follows from the experimental results that polycrystalline samples exhibited no transition to conductivity, while shock wave shaping affected the degree of transition to conductivity in single crystal KCl.
O12-7: Effect of Shock Wave Profile on the Magnetic Flux and Energy Transfer in
Miniature Ferromagnetic Primary Sources
S. I. Shkuratov1, J. Baird1, E. F. Talantsev2, L. Altgilbers3, A. H. Stults4
1Loki Incorporated, Rolla, MO, United States 2Pulsed Power LLC, Lubbock, TX, United States
3U.S. Army Space and Missile Defense Command, Huntsville, AL, United States
4U.S. Army Aviation Research, Development and Engineering Center, Huntsville, AL, United States
A miniature autonomous completely explosive pulsed power system containing a ferromagnetic primary power source and a loop magnetic flux compression generator (LFCG) has been experimentally and theoretically studied. The ferromagnetic generator (FMG) utilizing the transverse (shock wave propagates across the magnetization vector M) shock wave demagnetization of Nd(2)Fe(14)B hard ferromagnet produced the initial current that was amplified during the operation of the LFCG. It follows from the experimental results that the magnetic flux and energy transferred from the FMG to the LFCG-Load system depend on the profile of the shock wave generated in the Nd(2)Fe(14)B element. We performed numerical simulation of shock compression of Nd(2)Fe(14)B element within the FMG. Distribution of the shock pressure and temperature inside the Nd(2)Fe(14)B for different shock wave profiles are given and discussed. The FMG-LFCG-Load system of volume 52 cm3 was capable of producing output currents up to 5 kA with energy compression coefficient more than 3.0.
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O12-8: Operation of Longitudinal Shock Wave Ferroelectric Generators in the
Resistance Mode S. I. Shkuratov1, J. Baird1, E. F. Talantsev2, L.
Altgilbers3 1Loki Incorporated, Rolla, MO, United States
2Pulsed Power LLC, Lubbock, TX, United States 3U.S. Army Space and Missile Defense Command, Huntsville, AL, United States
Results of systematic experimental investigations of operation of explosive-driven longitudinal shock wave ferroelectric generators (FEGs) with resistance load are presented. One of the specific features of FEGs is direct electrical connection of the ferroelectric energy-carrying element to the load. The ferroelectric element is always a part of the load circuit during explosive and electrical operation of the FEG. Electrical parameters of the ferroelectric element change significantly under shock wave action during operation of the generator and it effects on the electrical parameters of the FEG-Load system. It follows from the experimental results that the output voltage, current and power produced by the FEG across the resistance load depend on both the electrical parameters of the load and geometrical dimensions of the ferroelectric energy-carrying element of the FEG. It is experimentally demonstrated that miniature FEG is capable of delivering in the active load a pulsed power with peak amplitude up to 0.35 MW. Detailed analysis of experimental results is given.
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WEDNESDAY
JULY 1
O13: Advanced Dielectrics
O14: Pulsed Power Systems
O15: Repetitive Pulsed Power and High Current Pulsers
01P: Microwave and RF Sources, Charged Particle Beams and Sources, Dielectrics and Energy Storage
02P: High Energy Density Plasmas and Pulsed Power Switches and Components
O16: Electromagnetic Launchers and Pulsed Power Systems
O17: Pulsed Power Capacitors
O18: Power Electronics and Systems
O13: Advanced Dielectrics Ballroom
Wednesday, July 1 9:15-11:15 S. M. Dirk
O13-1: High Temperature Polymer Dielectrics from the Ring Opening Metathesis Polymerization (ROMP)
1, P. S. Sawyer1, J. S. Wheeler2, M. E. Stavig1, B. A. Tuttle2
1Organic Materials Department, Sandia National Laboratories, Albuquerque, NM, United States
2Electronic and Nanostructured Materials Department, Sandia National Laboratories,
Albuquerque, NM, United States
Recently much research has focused on the development of new polymer dielectric materials to fabricate capacitors for use in the inverters of next generation hybrid electric vehicles (HEV). The capacitors used in HEVs inverters will be required to operate at 150 °C, 600V, and have an energy density of 0.9 J/cm3. Polymer based thin film capacitors are ideal for this application due to their relatively high energy density, low cost, and high dielectric breakdown strength. We have polymerized several ring strained monomers using ring opening metathesis polymerization (ROMP) and have identified a promising polymer system based on N-Phenyl-7-oxanorbornene-5,6-dicarboximide (PhONDI). Several of its copolymers with norbornene have been evaluated for possible use as next generation high temperature polymer dielectrics in thin film capacitors. The copolymers were cast into thin films and Au electrodes were deposited on the polymer film. The electrical properties were evaluated as a function of temperature. The polymer system exhibited very good high temperature dielectric properties and is potentially useful as a high temperature capacitor dielectric. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.
O13-2: Dielectric Characterization of Polymer-Ceramic Nanocomposites*
K. A. O'Connor, J. Smith, R. D. Curry Center for Physical and Power Electronics,
University of Missouri-Columbia, Columbia, MO, United States
Polymer-ceramic nanocomposites for high power applications are being developed at the University of Missouri-Columbia. Several polymers and epoxies have been investigated as candidate matrix materials. Composites with several loading factors of nanoparticles have been prepared. The matrix materials and composites are characterized through measurements of the dielectric constant and loss over a wide range of frequencies, dielectric strength in pulsed high voltage conditions, and scanning electron microscopy. Two test stands have been implemented for measurement of the complex dielectric permittivity in two frequency ranges of interest. Measurements from 100 kHz to 30 MHz are performed using parallel-plate methods and a precision LCR meter. Frequency measurements from 200 MHz up to 4.5 GHz are performed through network analysis. The nanocomposites were also characterized for dielectric breakdown. A test stand was built to characterize the nanocomposites under pulsed conditions. Dielectric strength measurements were conducted with a 40-125 kV pulse generator which produced a 60 ns risetime. A summary of the composite materials, diagnostic methods, and preliminary results are reported. The complex permittivity and dielectric strength are reported for several matrix material candidates. The permittivity, dielectric strength, and losses for a number of candidate composite materials will also be discussed. *Funding for this program was provided by ONR under contract number N00014-08-1-0267.
O13-3: Nonlinear Modeling of Ferroelectric Dielectrics Transmission
Line S. L. Henriquez1, M. S. Litz1, S. B. Bayne2,
D. Katsis3 1Directed Energy and Power Generation, U.S.
Army Research Laboratory, Adelphi, MD, United States
2Texas Tech University, Lubbock, MD, United States
3Athena Energy Corp., Bowie, MD, United States
This paper describes the use of barium strontium titanate, Ba0.6Sr0.4TiO3, (BST) as a dielectric medium in a parallel plate transmission line to control the frequency response of a 200MW high power microwave system. The physical dimensions of the dielectric were designed and modeled for a desired frequency response at L-Band frequencies. Layers of BST and aluminum oxide are stacked for 20 stages for an increased output response. The effects of increasing the amount of stages are demonstrated through the model development. Previous experiments have used air to spatially separate the dielectric medium for periodicity1. The accuracy of the models was compared against measured results. 20 stages of BST and alumina pairs were bonded together in an epoxy to remove pockets of air from between dielectric layer of the transmission line and to introduce uniformity between the alumina and BST package. The resulting physical dimensions of the ceramic block were 7.5mm x 25mm x 42mm. The results of this paper discuss the importance of the modeling process and its impact on the high power microwave source system development. The nonlinear transmission line is described a ladder of inductors and nonlinear capacitors. This system is modeled using PowerSim [2]. The nonlinear capacitor is modeled using a voltage controlled voltage source. Predictions of this model are compared to experimental data. The experimental results include two different spatially modulated transmission lines. The results of the model will be compared to the experimental data. Improved fabrications have minimized mismatches between the nonlinear transmission line and low impedance load. Modeling techniques results are expected to improve impedance mismatches in the experimental system. [1]. H. Ikezi, S. S. Wojtowicz, R. E. Waltz, J. S. deGrassie, and D. R. Baker, “High-power soliton generation at microwave frequencies,” J. Appl. Phys., vol. 64, no. 6, September 15, 1988, pp. 3277-3281. [2]. PSIM User Manual Verision 5.0, PSIM. May 2001.
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O13-4: Defect Modified PVDF Dielectric Polymers with Very High Energy Density
for Capacitor Application X. Zhou1, S. Zhang2, C. Zou3, Q. Zhang1,3
1Electrical Engineering, The Pennsylvania State University, University Park, PA, United States
2Strategic Polymer Science, Inc, State College, PA, United States
3Materials Research Institute, The Pennsylvania State University, University Park,PA, United
States
To meet the requirement of future high performance and compact systems, it is desirable to develop dielectric materials with high energy density. The high electric displacement (D>0.1 C/m^2) and breakdown field (>600 MV/m) in polyvinylidene fluoride based polymers suggest high electrical energy density in this class of polymers. By defect modifications which reduce or eliminate the remnant polarization in the polymer, a high electric energy density (>25J/cm^3) can indeed be obtained in defect modified PVDF polymers. Here, properties related to capacitor application, such as energy density, breakdown strengh, discharge speed and so on, will be presented for this class of materials
O13-5: Computation of Dielectric Response of Polymers with Nonlinear
Fillers K. Zhou, S. A. Boggs
Institue of Material Science,, University of Connecticut, Storrs, CT, United States
In previous work, we have configured COMSOL Multiphysics to solve 2-D and 3-D transient nonlinear paraelectric-polymer composite materials. By randomly embedding paraelectric particles with field dependent dielectric response into polymer matrix with constant dielectric response, the overall field dependent dielectric response of these composites can be analyzed as a function of volume fraction. However, the composite dielectric response is a strong function of the morphology of the particles within the polymer matrix. Here we compute the overall dielectric response for various particle morphologies at constant volume fraction and examine the effect of particle (agglomerate) “structure” on the dielectric response of such composite materials.
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O13-6: High Electric Field Properties of Bi-Based Perovskite Solid Solutions D. P. Cann, B. J. Gibbons, M. R. Emerson,
N. Triamnak Materials Science, School of Mechanical,
Industrial, and Manufacturing Engineering, Oregon State University, Corvallis, United States
The perovskite structure exhibits a wide range of solid solubility and recent results in the binary Bi(Zn1/2Ti1/2)O3-ABO3 system show great promise for high energy density applications. With the addition of 10-30 mole percent Bi(Zn1/2Ti1/2)O3 to common ferroelectric perovskites such as BaTiO3 and NaNbO3, the Curie temperature drops below room temperature and a pseudo-cubic perovskite phase appears. Interestingly, the dielectric response of these cubic phases is nearly linear with only a slight deviation at the highest fields (typically above 80 kV/cm). In contrast to most linear dielectrics, these materials are characterized by permittivities in excess of 1000 that persist to fields of 100 kV/cm. These high E-field properties are enabled by high densities in bulk ceramics and high insulation resistances. Measurement of the electric field induced strain of these materials show a parabolic E-field dependence which indicates no evidence of domain involvement. Microstructural analysis via transmission electron microscopy (TEM) revealed a complex non-uniform microstructure. While the precise mechanism is unknown, it is likely tied to limited kinetics during processing and a complex cation stoichiometry with multiple cations on the perovskite A and B sites. In this presentation, recent results on bulk ceramics and sputtered thin films will be presented.
O13-7: Potential High Temperature, High Energy Density Dielectrics for Multilayer
Ceramic Capacitors for Power Applications
C. A. Randall1, H. Ogihara1, S. S. N. Bharadwaja1, M. T. Lanagan1, S. Trolier-
McKinstry1, C. Stringer2 1Materials Research Institute, The Pennsylvania
State University, University Park, PA, United States
2Engineering Dept., The Pennsylvania State University-DuBois, DuBois, PA, United States
There is a need to expand the range of available materials that can operate at high temperatures and also can store transient electrical energy of the order of 4J/cc up to and above 200˚C. Many of the high permittivity materials have limitations such as voltage saturation and degradation mechanisms. Here we are looking at new dielectric materials with the perovskite structure that possess either linear dielectric characteristics or weak relaxor characteristics. The materials to be discussed involve solid solutions of calcium zirconate for the linear materials, and also new bismuth scandate-barium titanate solid solutions that are weakly non-linear, but with relatively high permittivities ~ 1000. The electrical challenges and processing of these materials will be discussed, as well as some of the basic physics influencing their properties.
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O13-8: Pulse Laser Deposition of Nd-Doped BaTiO3 Films for High Energy
Density Pulsed Power Capacitors P. S. Lee1, J. B. Lam1, M. F. Lin1, J. Ma2
1School of Materials Science and Engineering, Nanyang Technological University, Singapore,
Singapore 2Temasek Laboratories, Nanyang Technological
University, Singapore, Singapore
Pulse power in mobile platform requires high dielectric constant materials with high breakdown field strength for high energy density capacitors in energy storage and power compression devices. High energy densities of more than an order of magnitude than the current available commercial capacitors are required for microsecond discharge applications. In this work, we have utilized the pulse laser deposition (PLD) method in fabricating multi-layer thin film capacitors of Nd doped BaTiO3 (BTO) and pure BaTiO3. PLD targets were fabricated using the solid state reaction with varying Nd2O3 concentration. Various film thickness were deposited using the 248nm wavelength KrF excimer laser. Metal-insulator-metal capacitors were formed on the deposited films with Pt circular electrodes. High dielectric constants of 6400 and 4800 were obtained for measured frequency of 1kHz and 100 kHz respectively for 1 at% Nd doped BaTiO3 after vacuum annealing at 650 degC. The dielectric loss tangent is less than 0.006 at 100 kHz. Depending on the doping concentration of Nd, the dielectric breakdown field strength ranges from 7.6E+07 to 8.2E+06 V/m. X-ray Diffractometry (XRD) analysis shows the formation of polycrystalline tetragonal perovskite phase formed for the Nd doped BTO samples while the undoped sample is of monoclinic polycrystalline structure. Scanning Electron Microscope (SEM) imaging shows that these films are crack free and uniform. Atomic Force Microscropy (AFM) indicates a smooth surface morphology with rms of about 20 nm which explains the good dielectric behavior.
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O14: Pulsed Power Systems Colonial
Wednesday, July 1 9:15-11:15
O14-1: An Update on NIF Pulsed Power P. A. Arnold1, G. F. James1, D. E. Petersen1, D. L. Pendleton1, G. B. McHale1, F. Barbosa1,
A. S. Runtal2, P. L. Stratton1 1Lawrence Livermore National Laboratory,
Livermore CA, United States 2IAP World Services, Livermore CA, United
States
The National Ignition Facility (NIF) is a 192-beam laser fusion driver operating at Lawrence Livermore National Laboratory. NIF relies on three large-scale pulsed power systems to achieve its goals: the Power Conditioning Unit (PCU), which provides flashlamp excitation for the laser’s injection system; the Power Conditioning System (PCS), which provides the multi-megajoule pulsed excitation required to drive flashlamps in the laser’s optical amplifiers; the Plasma Electrode Pockels Cell (PEPC), which enables NIF to take advantage of a four pass main amplifier. More than a decade has been spent on the design, production, installation, and commissioning this hardware. It is now fully operational. Seven-day-per-week operation of the laser has commenced, with the three pulsed power systems providing routine support of laser operations. We present the details of the status and operational experience associated with the three systems along with a projection of the future for NIF pulsed power. *This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344.
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O14-2: Optimizing Compact Marx Generator Networks
C. J. Buchenauer Electrical and Computer Engineering
Department, University of New Mexico, Albuquerque, NM, USA
Compact linear Marx generators are frequently constructed in close-fitting metallic housings. The parasitic capacitance formed between the enclosure and Marx components can substantially exceed the inner stage capacitance and play an important role in the Marx network performance. This capacitance and the inner stage inductance form the components of a lumped-constant transmission line, which facilitates proper sequential firing of the spark switches. With appropriate component values, these Marx generators can deliver fast rising and nominally flat pulses into resistive loads. These same Marx generators may be thought intrinsically unsuitable for charging capacitive loads because of their large internal parasitic capacitance. When the total parallel parasitic capacitance exceeds the effective series capacitance of the charged capacitors, as little as two thirds or less of the stored energy may be transferred to the external load capacitor if driven directly by the Marx generator. In addition to the loss in transfer efficiency, the remaining energy induces high frequency oscillations in the Marx circuit that will lead to component heating and early failure. These problems can be avoided by suitable choices of Marx network component values, switch timing, and external network components. In fact, even with relatively large parasitic capacitance values, theoretical solutions are found for which energy transfer efficiencies of unity are achieved with lossless network components. Necessary and sufficient conditions for such solutions will be presented with examples and pspice simulations. A formal theoretical treatment of this problem is presented in a companion paper by Zaccarian et al.
O14-3: A Control Theory Approach on the Design of a Marx Generator Network
L. Zaccarian1, S. Galleani1, C. J. Buchenauer2, C. T. Abdallah2, E. Schamiloglu2
1DISP, University of Roma, Tor Vergata, Roma, Italy
2Electrical and Computer Engineering Department, University of New Mexico,
Albuquerque, NM, USA
A Marx generator is a type of electrical circuit first described by Erwin Otto Marx in 1924. It has since been utilized in numerous applications in pulsed power with resistive or capacitive loads. To-date the vast majority of research on Marx generators designed to drive capacitive loads relied on experimentation and pspice circuit modeling to guide their activities. In this presentation we describe how the problem of designing a Marx generator to drive a capacitive load is reduced to that of choosing a gain matrix F that places the eigenvalues of the closed-loop matrix A+BF at specific locations. Here A is the identity matrix and B characterizes the elements of the Marx generator and depends on the number of stages n. This formulation is a well-known problem in the area of feedback control, and is known as the static output feedback problem. While the problem is difficult to solve in general, due to the specific structures of the A and B matrices, various efficient algorithms exist to find solutions. In a companion paper by Buchenauer it is shown that if certain conditions hold, then setting the natural frequencies of the circuit to be harmonically related guarantees that all the energy is delivered to the load capacitor after a suitable delay. A theorem formalizing this result is presented.
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O14-4: PHELIX C. L. Rousculp, P. J. Turchi, W. A. Reass,
D. M. Oro, F. E. Merrill, J. R. Griego, R. E. Reinovsky
Los Alamos National Laboratory, Los Alamos, NM, United States
The Precision, High Energy density, Liner Implosion eXperiment (PHELIX) pulsed power driver is currently under development at Los Alamos National Laboratory. When operational PHELIX will provide 0.5-1.0 MJ of capacitively stored energy into cm size liners which will reach implosion velocities of 1-4 km/s with approximately 10-20 microsecond implosion time. Peak load currents will be in the 5-10 MAmp range. To do this the machine will utilize a reusable, multi-turn primary, single-turn secondary transformer to couple the 100-120 kV Marx capacitor system to the load. The transformer has been designed toward a coupling coefficient of 0.9. PHELIX is being designed to be portable with only an 8 x 25 ft2 footprint. This will allow the machine to be taken to the experiment designer’s diagnostic of choice. The first such diagnostic will the LANL proton-radiography facility. There the multi-frame, high-resolution, imaging capability will be used to study hydrodynamic and material phenomena.
O14-5: Evaluation of Conductor Stresses in a Pulsed High-Current Toroidal
Transformer P. J. Turchi, C. L. Rousculp, W. A. Reass, D. M. Oro, J. R. Griego, R. E. Reinovsky
Los Alamos National Laboratory, Los Alamos, NM, United States
The Precision, High-Energy density, Liner Implosion eXperiment (PHELIX) pulsed power driver is currently under development at Los Alamos National Laboratory. When operational PHELIX will provide 5-10 MAmps of peak current with pulse rise-time of ~5-10 μs. Crucial to the performance of PHELIX is a multi-turn primary, single-turn secondary, current step-up toroidal transformer, Rmajor ~ 30 cm, Rminor ~ 10 cm. The transformer lifetime should exceed 100 shots. Therefore it is essential that the design be robust enough to incur the magnetic stresses produces by high currents. In order to evaluate our design, two methods have been utilized. First, a theoretical evaluation has been performed. By identifying the magnetic forces as J2/2 L, where J is the electric current and L in the inductance of the system, estimates of stress can be obtained for a simple steady-state system. These results are then compared to a computational MHD model of the same system. Results will be discussed.
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O14-6: NDCX-II Pulsed Power System and Induction Cells
W. L. Waldron, L. L. Reginato, M. A. Leitner Lawrence Berkeley National Laboratory,
Berkeley, CA, United States
The Heavy Ion Fusion Science Virtual National Laboratory (HIFS-VNL) is currently developing design concepts for NDCX-II, the second phase of the Neutralized Drift Compression Experiment, which will use ion beams to explore Warm Dense Matter (WDM) and Inertial Fusion Energy (IFE) target hydrodynamics. The ion induction accelerator will include induction cells and Blumleins from the decommissioned Advanced Test Accelerator (ATA) at Lawrence Livermore National Laboratory (LLNL). A test stand has been built at Lawrence Berkeley National Laboratory (LBNL) to test refurbished ATA induction cells and pulsed power hardware for voltage holding and ability to produce various compression and acceleration waveforms. The performance requirements, design modifications, and test results will be presented.
O14-7: State-of-the-Art of a Transmission-Line-Transfer Based
Multiple-Switch Pulsed Power Technology
Z. Liu1, A. J. M. Pemen1, E. J. M. V. Heesch1, G. J. J. Winands2, K. Yan3
1Eindhoven University of Technology, Eindhoven, Netherlands
2TNO Science and Industry, Eindhoven, Netherlands
3Zhejiang University, Hangzhou, China
This article reviews recent works on a Transmission-Line-Transformer (TLT) based multiple-switch pulsed power technology. By interconnecting multiple switches via a TLT, all switches can be synchronized automatically and no external synchronization trigger circuit is required. High-power pulses can be realized either by voltage adding or by current multiplication. In comparison with a single-switch circuit, the switching duty or switching current for each switch is reduced by a factor n (where n is the number of switches). As a result, the switch lifetime is expected to improve significantly. It can produce either exponential or square pulses, with various voltage and current gains and with a high degree of freedom in choosing output impedances. This technology has been investigated systematically. An equivalent circuit model was introduced to gain insight into the fundamental principle, and agrees with experimental observations. The feasibility of producing efficient high-power fast-rising short pulses has been proven with a ten-switch prototype. The ten-switch setup has been successfully demonstrated at a repetition rate up to 300 pulses per second (pps). Pulses with a rise-time of about 10 ns, a pulse width of about 55 ns, a peak output power of 300-810 MW, a peak output voltage of 40-77 kV, and a peak output current of 6-11 kA have been obtained with an energy conversion efficiency of 93-98%. Proper operation of the μs large current pulse generation by using multiple thyristors has been verified, which can be used for powerful electrohydraulic discharge. In addition, the proposed multiple-switch topology can also be applied in other well-known circuits, e.g. Blumlein generator, Inductive-Voltage-Adder (IVA), etc.
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O14-8: Transients in the Capacitor Cells Circuits and Semiconductor Switches
Workability R. S. Enikeev, B. E. Fridman
STC, D.V. Efremov Scientific Research Institute of Electrophysical Apparatus, St.-Petersburg,
Russian Federation
The paper considers capacitor cells with the pulse forming network and semiconductor switches, including reverse-switched dynistors (RSD) and power semiconductor diodes [1]. Conditions for switches operating in the programmable discharge mode, overvoltage limitations by snubber circuits and varistors, prevention of overvoltages processes by soft recovery diodes, control of the semiconductor structure heating by measuring the electrical parameters, diodes reverse recovery behavior are investigated on pilot cells. Peculiar features of RSD and diodes operation are investigated, including possible emergence of reverse voltage on RSD anodes before their triggering in case of a current pause in RSD and their repeatable switching in the programmable discharge mode, as well as generation of switching overvoltages on the diodes. The methods providing reliable and stable switching are tested, including in-series connection of protective diodes with RSD, insurance of capacitor discharge through RSD, application of snubber circuits and varistors. Fast and soft reverse recovery diodes were investigated in the surge current mode and in the programmable discharge mode. 1. B.E. Fridman, et al. Energy Storage Capacitor Cell with Semiconductor Switches. In Proc. 2007 IEEE Pulsed Power Conf., p. 542 545.
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O15: Repetitive Pulsed Power and High Current Pulsers
Chinese Room
Wednesday, July 1 9:15-11:15
O15-1: A 2MV, <300ps Risetime, 100Hz, Pulser for Generation of Microwaves
D. Morton1, J. Banister1, J. S. Levine1, T. Naff1, I. Smith1, H. Sze1, T. Warren1, D. Giri2, C. Mora3,
J. Pavlinko3, J. Schleher3, C. Baum4 1L3 Pulse Sciences, San Leandro, CA, United
States 2Pro-Tech, CA, United States
3SAIC, ABQ, NM, United States 4University of New Mexico, NM, United States
HPM WBTS (High Power Microwave, Wide-Band Threat Systems) is a high power, repetitively pulsed, wide-band microwave generator capable of 100Hz burst operation. The HPM WBTS microwave capability covers the range of 200MHz to 6GHz in nine frequency bands. E-Field specification at target is 30-110 V/m/MHz depending on frequency. The system is transportable, capable of being set up at remote sites and operation on generator power. The HPM WBTS is composed of several modules all of which store and transport in a standard 40’ container. The pulser and its accompanying power supplies, controls and ancillary systems are housed in a ‘pallet’ structure which can be moved when needed. The system is operated remotely via a fiber-optic linked lap-top computer. The system incorporates built-in diagnostics and data acquisition capability. The HPM WBTS pulser produces a short (<1ns, full width half maximum) >2MV negative pulse with a rise-time of <300ps (10-90%) into the antenna load. The HPM WBTS is capable of operation at 100Hz with burst lengths of up to 500 pulses**. Rep-rate and burst length are fully programmable. Voltage can be adjusted down to <50% of maximum using a combination of hardware changes and charge voltage adjustment. To accommodate nine different antennas with unique sizes and voltage requirements, four swappable PFL (pulse forming line) assemblies are utilized. Each PFL is tuned for its corresponding antenna set. The PFLs are oil switched using an innovative geometry capable of generating the ~6.7x1015 volts per second slew rate into the antenna. The PFL are charged through a unique self-breaking, SF6 insulated edge-plane transfer switch (TS). The TS discharges an oil insulated transfer capacitor which is in turn charged by a low-inductance, compact folded geometry Marx generator. This paper will focus on the design and performance of the Marx, TS, PFLs, oil switching and antenna feed features of the HPM WBTS. An accompanying paper at this conference will describe the overall HPM WBTS system(1). A detailed description of the pulse power design
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and electrical waveforms data taken from both computer simulation and field testing will be presented. Radiated E-field measured data are not included. * The authors would like to thank the Test Resource Management Center (TRMC) Central Test and Evaluation Investment Program (CTEIP) for their support. This work is funded by CTEIP's Directed Energy Test and Evaluation Project (DETEC) under PEO STRI contract number N61339-00-D-0710-0027. ** Maximum Voltage, Rep-rate and Burst Length Specification are non-concurrent. (1) “HPM WBTS A Transportable High-Power Wide-Band Microwave Source,” D. Morton, J. Banister, T. DaSilva, J. Levine, T. Naff, I. Smith, H. Sze, T. Warren, D. Giri, C Mora, J. Pavlinko, J. Schleher, C. Baum, IEEE Pulsed Power Conference 2009.
O15-2: Compact Solid State Modulator & RF System
S. M. Iskander
Power Tubes & Systems, E2V Technology, Chelmsford, United Kingdom
The paper describes the MPT583x series, a successful development and commercial application of pulsed RF power manifested in a solid state modulator and magnetron as an RF source at a sub system level. The modulator design is rated at 55 kV peak pulse amplitude at 250A peak current with 13 kW mean power continuous operation, repetitive pulse system driving high power magnetrons such as the MG5028 (5MW peak RF) and MG5193 (2.6MW peak RF), with output RF power of up to 5MW peak and 4 kW mean. It is based substantially on the FET-based solid-state direct-switched repetitive pulse modulator developed in the early part of the 21st century We highlight the key technical challenges addressed during the development, including performance issues, fault handling, and control of a compact solid state modulator. The modulator uses a series switch, which connects a capacitor bank to a load for the duration of the received drive (trigger) pulse. These products have a standard physical package for all the applications This system is integrated from wall socket to RF pulse power. The MPT583x series of products is based around proven MOSFET technology developed over the preceding 5 years and proven on in-house high power magnetron test equipment.
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O15-3: High Repetition Rate Pulsed Power Generator Using IGBTs and
Magnetic Pulse Compression Circuit T. Sakugawa1, K. Kouno1, K. Kawamoto1, H. Akiyama1, K. Suematsu2, A. Kouda2,
M. Watanabe2 1Graduate School of Science and Technology,
Kumamoto University, Kumamoto, Japan 2Suematsu Electronics Co. Ltd., Yatsushiro,
Japan
Recently, all solid-state pulsed power generators, which are operated with high repetition rate, long lifetime and high reliability, have been developed to be used for industrial applications, such as high repetition rate pulsed gas lasers, high energy density plasma (EUV sources) and pulse ozonizer. Re-quirements of these applications are repetitive fast rise time pulsed power. Recently, semiconductor power device technology has improved the performance of fast high voltage switching and low switching loss. In particular, insulated gate bipolar transistor (IGBT) is highly efficient semiconductor switching device. However, the IGBT switch is still not sufficient to drive the pulse laser and the pulse ozonizer themselves. In practical systems, semiconductor switches are used with the assistance of magnetic switches. We have studied and developed high repetition rate small size pulsed power mod-ulator for generation of discharge plasma. This generator consists of an IGBT switch circuit, a step-up pulse transformer and magnetic pulse compression (MPC) circuit. This modulator is able to generate an output voltage of about 12kV with voltage rise time of less than 100 ns. And repetition rate are up to 1000 pulses per second (pps). We did the operation test and generate the streamer discharge with 1000 pps.
O15-4: Repetitive Solid State Pulse Modulator Based on a DC Voltage
Multiplier L. M. S. Redondo1, 2
1Instituto Superior de Engenharia de Lisboa, Lisbon, Portugal
2Centro de Fsica Nuclear da Universidade de Lisboa, Lisbon, Portugal
The use of repetitive high-voltage pulses is, nowadays, spreading fast into many environmental, biological, medical and industrial applications, needing new flexible and compact pulsed power topologies with optimized performance, taking the most of semiconductor technology. We will report on a newly developed solid-state repetitive high-voltage (HV) pulse modulator topology created from the mature concept of the dc voltage multiplier configuration. DC voltage multipliers (VM) have been around for decades for HV dc generation from relatively low ac voltages, in wide different applications. Essential, two different types of VM are used, where the output voltage comes from a series of capacitors with lower breakdown voltages (e.g. the common Cockcroft-Walton circuit), or from a single capacitor with higher voltage rating. The first connection is recommended when generating high voltages at low currents and the second one is recommended when generating lower voltages at higher currents. The circuit here proposed is based in the second VM type circuit, where a number of dc capacitors share a common connection and the voltage rating in each one is different. Hence, besides the standard VM diodes, two solid-state on/off switches are used, in each stage, to commutate from the typical charging VM mode to a pulse mode with the dc capacitors connected in series with the load. Due to the on/off semiconductor configuration, in half-bridge structures, the maximum voltage blocked by each one is the dc capacitor voltage in each stage. Comparing with the Marx modulator concept, where a number of capacitors are charged in parallel with a dc voltage supply, and discharge in series into the load. In this circuit, a number of dc capacitors are charged in parallel with an ac voltage supply and discharged in series into the load. However, in relation to the Marx generator, here the capacitors have growing dc voltage ratings, which allows for reaching higher voltages with less stages. The high voltage measurements of the new modulator topology output will be presented and compared with the results of circuit simulations.
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O15-5: Design and Operation of a 700 kV Arbitrary Waveform Generator
R. J. Adler, V. M. Weeks Applied Energetics, Tucson, AZ, United States
The control of voltage in an arbitrary manner has lead to fundamental advances in fields which range from music to lasers. Such generators have traditionally been limited to a maximum voltage of 10 V. We have conceived, developed, tested and operated an arbitrary waveform generator with a range of voltages up to 720 kV. These devices have a wide variety of applicability. They are effective, high capability devices for simple square wave generation, and they also allow for a remarkable range of waveforms to be produced. The generators we have built are similar in some ways to solid state Marx generators, but with a novel charging system. The unit is also similar to the type of device described by Swanson in US Patent 4,403,197. The topology consists of a set of pulse generators arrayed in series where each pulse generator has a shunt diode. Each of the subunits can be on or off. We array the subunits in series. If M units are on at a voltage V we have voltage MV. We vary M in order to make an arbitrary voltage. The stages are truly independent, so the voltage of an individual stage device never increases due to the action of the other devices. This is in contrast to the action of switching in a series IGBT stack where one slow device will be subjected to N times its rated voltage. The main problem is to charge the stage capacitances C1...CN. We have developed a novel means of charging the stages using air core magnetic flux. We place the stages inside rings which have secondary coils on them. We arrange outside the rings - and with adequate spacing - to have a primary coil which provides a time varying axial magnetic field. The individual stages are charged with voltage multipliers connected to secondaries coupled to the magnetic field. In this paper we describe successful construction and operation of one of these devices up to 720 kV.
O15-6: Development on Repetitive Pulsed-Power Switching
W. Jiang1, X. Wang1, K. Liu2, J. Qiu2, H. Li3 1Tsinghua University, Beijing, China 2Fudan University, Shanghai, China
3China Academy of Engineering Physics, Mianyang, China
Repetitive pulsed power generation has been studied at different power levels by using gap switches, magnetic switches, semiconductor switches and photo-conductive switches, respectively. This is a systematic research program aimed at commercial applications of pulsed power technology to gas discharge, ion implantation, particle acceleration, and other fields. High pressure spark-gap switches are studied for repetition rate below kHz at high power level. The investigation is concentrated on the breakdown strength dependence on the pulse repetition rate. Magnetic pulse compression are studied for repetition rate in the range of kHz - 100 kHz at medium power level. The development received cooperation from magnetic-core manufacturers. Semiconductor and photo-conductive switches are studied for very short pulse width and very high repetition rate at relatively low peak-power level. Research interests are mainly on switching efficiency and device temperature control. Switching-device combination and circuit configuration design are considered as key issues toward designing compact repetitive pulsed power generator systems for specified applications. This work is sponsored by National Natural Science Foundation of China (NSFC), under Contract No. 50837004.
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O15-7: High Power FID Pulsers with Amplitude of up to 500 kV and Energy in
Pulse of 1 kJ V. M. Efanov, M. V. Efanov, A. A. Dyublov,
N. K. Savastianov FID GmbH, Burbach, Germany
A new series of high power pulse generators for plasma chemistry, accelerators, and pumping of high-power lasers has been developed. These air-cooled pulsers are based on all-solid-state semiconductor switches having turn-on time of less than 1 ns and peak current of up to 100 kA. The largest generator of this series has dimensions of 1200x400x300 mm, and delivers 500kV pulses with rise time of 1 ns into 100-1000 Ohm load. Energy in pulse can reach 1 kJ. At amplitude of 100-500 kV and pulse duration of 5-100 ns the pulse repetition frequency can be up to 1 kHz. Voltage pulses have high amplitude stability: the typical jitter is less than 100 ps. Many such pulse generators can operate into single load. All pulse generators of this series have efficiency of about 90%, which enables users to realize tens of kilowatts without liquid cooling.
O15-8: Mathematical Models of Conductive Media Explosion at
Extremely High Linear Current Density S. I. Krivosheev, G. A. Shneerson, Y. E. Adamian High Voltage Techique, Sankt-Petersburg State
Politechnical University, Saint Petersburg, Russian Federation
In current carrying elements of modern high pulsed current generators and miniature single turn coils magnetic field induction on conductor surface can achieve values up to 10^2-10^3 T. Corresponding linear current density is 10^8-10^9 A/m, and current density in skin layer reaches 10^11-10^13 A/m2. At these conditions forming of shock wave, expansion and cooling of media near conductor surface take place. Full-scale computer modeling of skin layer explosion using updated equations of state and dependences of media conductivity on temperature and density presents very complicated pattern of media flow. Interpretation of computational results is possible by their comparison with calculations using simplified models and analytical estimations. Process of shock wave forming and peculiarities of nonlinear field diffusion near the shock-wave front are examined in paper presented. Numeric modeling at varied current rise laws is used. Calculation results allow determination of the shock-wave front structure and features of stationary flow forming. Also process of separation of pressure and current waves fronts is studied. Along with movement of “field-conductor” boundary in the flow beyond the shock-wave front important role in skin layer explosion process plays expansion of the gas into field area. It is shown that sharp drop of the conductivity near the boundary can lead to additional energy release and forms conditions for ejection of low density gas into the field area. Analysis of this process jointly with the flow beyond the shock-wave front gives opportunity to describe electric explosion impact on the current in discharge circuit.
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01P: Microwave and RF Sources, Charged Particle Beams and Sources, Dielectrics and Energy Storage
East/State
Wednesday, July 1 11:15-12:30
01P-1: Aging Characteristic of Insulation Materials under Laser Irradiation and
Pulsed Discharge J. Wang 1, R. Z. Pan1, 2, P. Yan1
1Institute of Electrical Engineering, Chinese Academy of Sciences, BeiJing, China
2Graduate University, Chinese Academy of Sciences, BeiJing, China
The laser-triggered flashover switch can achieve precision synchronization, which has a low jitter and delay. The operating life is the important parameter of the switch. The aging of insulation materials is the main influence factor to limit the switch life. The wavelength of 1064/532 nm laser and ns pulse discharge are forced on insulators. The energy density of 1064(532) nm laser is from 2.0mJ/mm2 to 8.5mJ/mm2 (0.5mJ/mm2 to 5.1mJ/mm2). laser is focused with 2mm30mm rectangle. The discharge current is from 10A to 1000A. The material of electrode is stainless steel and the diameter is 100mm.Three kinds of insulations include nylon 6, polycarbonate and Al2O3, are tested in the experiment. The relation of laser irradiation times (different laser energy) and flashover field of insulation is given. The surface appearance of insulation materials under laser irradiation and discharge is observed by photon microscope. The flashover field measurement combined with surface appearance observation, the aging mechanics under laser irradiation and discharge is discussed. The experimental results show that the nylon 6 has the best arc and laser resistance and the highest electric strength is the polycarbonate among these insulation materials.
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01P-2: High-Voltage Pulsed Breakdown Testing of Organic Composite Dielectrics
M. Roybal1, J. Buchenauer1, E. Schamiloglu1, J. Rossi2, S. Sawhill3, E. Savrun3
1University of New Mexico, Albuquerque, NM, United States
2National Institute for Space Research, São José dos Campos, Brazil, United States
3Sienna Technologies Inc., Woodinville, WA, United States
The Pulsed Power, Beams, and Microwaves Laboratory at the Electrical and Computer Engineering (ECE) Department at the University of New Mexico (UNM) in collaboration with Sienna Technologies, Inc. are developing high energy storage materials as supported by DoD. For many future pulsed power systems, it is necessary for the dielectric material to have a large dielectric constant in order to achieve a higher energy density electrical device. Unfortunately, ceramics with high dielectric constant typically have lower breakdown strength (< 1.0 MV/cm) compared with organic and thermoplastic materials. In view of this, to achieve high energy densities (> 0.5 J/cm3) in dielectrics the present trend consists of casting in a mold a composite material composed of granulated ceramic embedded in an organic dielectric matrix. In an effort to accomplish this, Sienna Tech. has been responsible for fabrication of the organic composite dielectric samples while UNM performs the electrical characterization of this material. This presentation presents information based on the pulsed power breakdown tests that where preformed on these materials and its results for future organic dielectrics.
01P-3: Research Progress of Multilayer High Gradient Insulator Technology
C. Y. Ren, W. Q. Yuan, D. D. Zhang, J. Wang, P. Yan
Institute of Electrical Engineering, Chinese Academy of Sciences, BeiJing, China
In order to satisfy application demand for high performance and miniaturization of pulsed power system, multi-layer HGI (high gradient insulators) were designed and fabricated. Using high temperature laminated method; we developed two types of HGI which were fabricated from interleaved layers of brass and PI (polyimide), stainless steel and FEP (fluorinated ethylene propylene). Small samples and large insulation rings of HGI were obtained. The surface state and vacuum out-gassing characteristics of HGI samples were detected, respectively. Based on the vacuum experimental platform of nanosecond (10ns/35ns) pulse source with Marx generator and single coaxial pulse-forming line, the vacuum surface flashover characteristics of HGI samples were tested. The flashover characteristics of conventional insulation materials, such as PMMA (polymethyl methacrylate), were also measured in same test platform. The results shown that flashover taken place in the rising period of voltage, and the maximal vacuum flashover field intensity of HGI samples was close to 180kV/cm. The surface states of HGI samples had important influence on flashover characteristics, which were also further study emphases.
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01P-4: Methods to Increase Hold off Voltage of Polystyrene Dielectric J. L. Zirnheld, K. M. Burke, S. Olabisi,
J. D. Campbell Energy Systems Institute, University at Buffalo,
Buffalo, NY, United States
This paper discusses experimental studies conducted to determine the effects of methods to increase the electrical stress limit of polystyrene dielectric samples. Surfaces of samples were laser annealed to create a more uniform surface and decrease voids where voltage may accumulate. Geometry of the dielectric samples were considered with the aim of reducing electric field intensity at the triple point formed by the cathode, dielectric, and ambient environment. The triple point can lead to increased electric field and become a source for electron emission. The dielectric samples were subjected to high voltage stress via a custom built partial discharge analyzer (PDA) capable of delivering 40 kVac, 20 kV dc or ac superimposed on dc. Preliminary results have shown that annealing of the surface has increased the hold-off voltage of the dielectric samples in comparison to benchmark samples that were not annealed. Studies have shown that reduction of the electric field intensity at the triple point can increase the voltage at which secondary electron emission avalanche initiates, which is widely agreed upon as the process preceding the onset of surface flashover. Experimental results are discussed and related to factors of interest including electric field intensity at the triple point, flashover hold off voltage and correlation with methods applied.
01P-5: Breakdown Strength of Al2O3 Doped Polymer Layers
S. S. M. Chung1,2, C. H. Cheng3, J. Y. Jian3, J. W. Lan1, H. Y. Lin4, S. H. Cheng5, T. W. Suen6
1of Elecronics Engineering, Southern Taiwan University of Technology, Tainan, Taiwan
2Center for Micro/Nana Science and Technology, National Cheng Kung University, Tainan, Taiwan 3Department of Chemical Engineering, Southern
Taiwan University, Tainan, Taiwan 4Mechanical and System Research Laboratory,
Industrial Technology Research Institute, Hsinchu, Taiwan
5Institute of Nuclear Energy Research, Atomic Energy Commission, Taoyuan, Taiwan
6Electronic Research Division, Chung-Shan Institute of Science and Technology, Taoyuan,
Taiwan
High energy capacitors occupies most of the volume and weight of any Pulsed Power system, and the breakdown strength is the key to high energy storage since the stored energy is C=CV2/2 and C=eA/d. Adding nanoparticles to form nanocomposite usually increases the imaginary part of dielectric constant and permittivity several folds, which is useful in Radar Absorbing Material (RAM), but the effect on breakdown field is less unanimous. In pulsed condition, these nanoparticles sometimes increases breakdown field due to shielding effect from accumulated interface charges, but the effectiveness is a function of pulse length. In DC condition, breakdown field and stored energy some times decreases due to new path created by these nanoparticles for hot-electrons and concentrated local electric field, but this is a function of particles sizes and doped concentration. A remedy for DC condition may be layers of nanocomposites with blocking layers in between to increase the hold off voltage. We will report breakdown field measurements of epoxy doped with Gama phases of 1-9 phr Al2O3 and Polyimide doped with Alpha phases of Al2O3 in 1-7 weight %, and the combinations of them.
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01P-6: High Voltage Insulator Failures and Improvements Made in the Oil and
Water Section of the Z Machine at Sandia National Laboratories in 2008
B. S. Stoltzfus 1671, Sandia National Labs, Albuquerque, NM,
United States
Many changes were made to the Z machine oil and water section in 2007 as part of the Z refurbishment project. As Z was returned to routine operation, a number of the new component designs required modification. While none of the presented failures affected load performance, they did result in significant time and cost for machine maintenance. This paper summarizes the oil and water section insulator failures encountered in 2008 along with a description of the solutions implemented.
01P-7: A New Model of a Lightning Channel Corona Sheath During
Discharge J. M. Cvetic1, B. I. Jeftenic2, P. Osmokrovic1,
S. D. Marjanovic3 1Dept. of Microelectronics, Faculty of Electrical
Engineering, Belgrade, Serbia 2Dept. of Electrical Drive, Faculty of Electrical
Engineering, Belgrade, Serbia 3Dept. of Gaseous Electronics, Institute of
Physics, Belgrade, Serbia
A generalized lightning traveling current source return stroke model (GTCS) has been used to examine the dynamics of the lightning channel corona sheath surrounding a thin channel core. Based on the results of the laboratory measurements of the corona discharge of Cooray, 2000, a constant magnitude of electric field inside the channel corona sheath during discharge is assumed. The new model includes the charge diffusion introduced by Maslowski et al. 2009. The corona sheath surrounding thin channel core consists of two zones containing charge, zone 1 (inner zone containing net positive charge) and zone 2 (zone containing negative charge surrounding zone 1), respectively, and an outer zone 3 surrounding zone 2 without charge. Theoretical expressions for the corona sheath radii and the velocities are derived for the GTCS model and applied to different travelling-current-source types of models. The classical traveling current source model, the Diendorfer-Uman model, and the modified Diendorfer-Uman model are considered. It is concluded that the outer radius of zone 1 first increases and then decreases with time. The expressions of radial electric field inside zones 1 and 2, as well as in the vicinity but outside of zone 2, are derived. It is shown how the radial electric field is connected with the channel charging function introduced by the GTCS. Using these expressions and the measurements of Miki et al. 2002, we calculated the channel charging function from the radial electric field measured in the immediate vicinity of the lightning channel. As a result, the corona sheath radius and the velocity vs. time are calculated. The theoretical and the calculated results derived in this study give the new insights into the dynamics of the discharge of the lightning channel corona sheath. They could be used in further investigations of the conductivity of the plasma channel vs. time and height as well as for the validation of the different return stroke models.
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01P-8: Pulsed Breakdown Voltage Characteristics of Pressurized Carbon Dioxide up to Supercritical Conditions
T. Kiyan1, K. Miyaji1, M. Takade1, H. Fukuhara2, M. Hara1, H. Akiyama1
1Graduate School of Science and Technology, Kumamoto University, Kumamoto, Japan 2Department of Electrical and Computer
Engineering, Kumamoto University, Kumamoto, Japan
It is very interesting work from viewpoint of green chemistry because both of discharge plasma and supercritical fluids have higher chemical reactivity potential and unique characteristics. The generation of discharge plasma in media will generate various reactive species such as high-energy electrons, radicals, ultraviolet rays and so on. Those are able to enhance chemical reaction in media or to promote some reaction. On the other hand, the chemical reaction schemes in supercritical fluids have been accomplishing in various ways for its industrial applications. Therefore, the productions of discharge plasma in supercritical condition may offer great possibility in reaction engineering. In our previous work, we have been reported about the discharge characteristics in each phase including supercritical conditions of carbon dioxide using direct current power supply by point-to-plane electrodes with a few hundred micro gaps. In order to control large volume plasma or stable non-thermal plasma, we investigated pulsed breakdown voltage characteristics of pressurized carbon dioxide up to supercritical conditions. We report the experimental results about pulsed breakdown voltage in carbon dioxide media within the pressures range of 0.1 to 15 MPa at several constant temperatures. We also report area effect on pulsed breakdown voltage in supercritical carbon dioxide.
01P-9: An Evaluation of Dielectric Materials for Use in Pulsed Power
Devices P. J. Leask, R. A. Ibbotson, S. J. Evans
Advanced Technology Centre, BAE Systems, Bristol, United Kingdom
The use of high dielectric strength insulating materials in the field of pulsed power is of fundamental importance. Over the last few years there has been a constant drive for increasingly compact high voltage devices, and this requires dielectric materials that have breakdown strengths which are greater than those of established substances. In order to evaluate new novel insulating materials we have undertaken a study into various liquids, gels and solids. The experimental set-up for this investigation used an 8 stage Marx generator in order to produce a high potential difference between two uncoated stainless steel spherical electrodes. The electrodes were insulated by the material under test and were spaced 1.5 to 3.5 mm apart. The breakdown voltage of each of the samples was recorded as a function of the gap distance, and the data was then post-processed in order to determine the breakdown strength of each of the samples. A number of materials were identified in the study that had very high breakdown strengths and these are now being incorporated into our compact pulsed power devices. In addition to these tests, investigations were also undertaken on electrodes coated with a number of dielectric materials. The use of electrode coatings in order to increase voltage hold-off is a well-known technique and papers describing it go back over 40 years. However, almost all of the previous coating studies describe their use in gas insulated or vacuum gaps whereas in this measurement the dielectric coatings were used for an oil insulated gap. A number of materials were identified which increased the breakdown voltage by up to 60% over uncoated electrodes.
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01P-10: Phenomena Accompanying the Pulsed Electric Discharges in Water P. G. Rutberg, V. A. Kolikov, M. E. Pinchuk,
A. Y. Stogov, V. N. Snetov Institute for Electrophysics and Electric Power Russian Academy of Science, St. Petersburg,
Russian Federation
Spreading of the photoionization and the shock waves fronts produced at pulsed electric discharges across the metal electrodes in water has been investigated. Rate of a current in the channel of the discharge up to 10^10 А/s, pulse duration 0.2 s. It was determined that velocity of the shock waves spreading at an initial stage of the discharge is defined by that of the photoionization front and reaches 2*10^4 m/s. Data on characteristics and structure of photoionization front depending on discharge power and interelectrode gap are presented.
01P-11: Progress on Simulating the Initiation of Vacuum Insulator Flashover
M. P. Perkins, T. L. Houck, J. B. Javedani, G. E. Vogtlin, D. A. Goerz
National Security Engineering Division, Lawrence Livermore National Laboratory, Livermore, Ca,
United States
Vacuum insulators are critical components in many pulsed power systems. The insulators separate the vacuum and non-vacuum regions, often under great stress due to high electric fields. The insulators will often flashover at the dielectric vacuum interface for electric field values much lower than for the bulk breakdown through the material. Better predictive models and computational tools are needed to enable insulator designs in a timely and inexpensive manner for advanced pulsed power systems. In this talk we will discuss physics models that have been implemented in a PIC code to better understand the initiation of flashover. The PIC code VORPAL [1] has been ran on the Linux cluster Hera at LLNL. Some of the important physics modules that have been implemented to this point will be discussed for simple angled insulators. These physics modules include field distortion due to the dielectric, field emission, low energy secondary emission models, and insulator charging. In the future we will incorporate physics modules to investigate the effects of photoemission, electron stimulated desorption, gas ionization, and magnetic insulation. This work will lead to an improved understanding of flashover initiation and better computational tools for advanced insulator design. [1] Tech-X Corporation, 5621 Arapahoe Ave., Suite A, Boulder, CO, 80303. http://www.txcorp.comThis work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
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01P-12: Cavity Initiation Through an Evaporating Mechanism for the Pulse
Breakdown in Liquids V. M. Atrazhev1, V. S. Vorob'ev1,
I. V. Timoshkin2, S. J. MacGregor2, M. J. Given2 1Theoretical Department, Institute for High
Temperatures, Moscow, Russian Federation 2Department EEE, University of Strathclyde,
Glasgow, United Kingdom
The influence of the hydrostatic pressure, temperature and the duration of the applied voltage on the electric strength of dielectric liquids was studied experimentally by many researchers [1-4]. It has been established that the electric strength of the insulating liquids is practically independent on the duration of the applied voltage for impulses longer than several ms. For shorter impulses (<1ms) the measured breakdown strength increases rapidly with the decrease in the pulse duration and approaches its ionization avalanche limited value [5]. It is known that the impact electron ionization in the dielectric liquids does not depend on external pressures and temperatures, which suggests that the breakdown process in these liquids can occur through a gas phase [6, 7]. This approach assumes that the liquid is heated by the pre-breakdown electrical currents due to high field electron emission from the cathode [6]. As a result of such local heating, the liquid boils generating vapor-filled bubbles, and the electric breakdown potentially occurs through the suspension of the bubbles in the liquid. The present paper considers a thermal mechanism of the electrical breakdown in the insulating liquids through the formation of the vapor bubbles. The formation of the bubbles is analysed using the theory of homogeneous nucleation in a superheated liquid. Concentration of the bubbles, their radiuses and time of growth are estimated. The electric breakdown of the vapor bubbles filled with different molecular gases is described in the frameworks of the percolation theory using the Paschen curves for these gases [8]. Obtained analytical expressions which link the breakdown strength of the insulating liquids with their temperature, external pressure, inter-electrode gap length and duration of the impulse are given in the paper. These analytical results are compared with the experimental data available in the literature. [1] K.C. Kao and J.B. Higham, J. Electrochem. Soc., Vol.108, p522, 1961. [2] K.C. Kao and J.P.C. McMath, IEEE Trans. Electr. Insul., Vol.EI-5, p.64, 1970. [3] K. Yoshino, H. Fujii, K. Hayashi, U. Kubo and Y. Inuishi, J. Electrostatics, Vol.7, p.103, 1979. [4] M.D.Cevallos, M.D. Butcher, J.C. Dickens, A.A. Neuber, and H.G. Krompholz, Proc. of the
15th Int. IEEE Pulsed Power Conference, Monterey, CA, June 13-17, 2005. [5] V.M. Atrazhev, E.G. Dmitriev, I.T. Iakubov, IEEE Trans. Electr. Insul., Vol.26, p.586, 1991. [6] P.K. Watson and A.H. Sharbaugh, J. Electrochem. Soc., Vol.107, p.516, 1960. [7] K.C. Kao, IEEE Trans.Electr.Insul., Vol.EI-11, p.121, 1976. [8] J.S. Mirza, C.W. Smith, and J.H. Calderwood, J. Phys. D: Appl. Phys., Vol.4, p. 1126,1971.
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01P-13: Pre-Breakdown Currents in Insulating Liquids Stressed with Non-
Uniform DC Electric Field I. V. Timoshkin, M. J. Given, S. J. MacGregor,
M. P. Wilson Department of EEE, University of Strathclyde,
Glasgow, United Kingdom
Insulating liquids are widely used in power industry and high voltage systems including pulsed power components. In the pulsed power systems insulating liquids are often stressed with impulse, uni-polar and highly divergent electric fields. Understanding of the pre-breakdown mechanisms and processes in such conditions is important for the optimization of practical applications of the dielectric liquids. This paper discusses a study of the pre-breakdown activity in different insulating liquids: various types of transformer oils and synthetic ester liquid. These liquids were stressed with the DC highly non-uniform electric fields in a needle-plane electrode system. The needle electrode was connected to a positive or negative high voltage DC power supply and the plane electrode was grounded. The pre-breakdown currents in the dielectric liquids were observed using a trans-resistance amplifier. The paper discusses the differences in the behavior of the pre-breakdown currents including anode and cathode impulses in the different insulating liquids. These results may help to improve understanding of the basic processes in liquid dielectrics which lead to the breakdown.
01P-14: Impulse Breakdown Characteristics of Dielectric Materials
Immersed in Insulating Oil M. P. Wilson1, S. J. MacGregor1,
I. V. Timoshkin1, M. J. Given1, M. A. Sinclair2, K. J. Thomas2, J. M. Lehr3
1Dept. Electronic & Electrical Engineering, University of Strathclyde, Glasgow, United
Kingdom 2Pulsed Power Group, AWE Aldermaston,
Reading, United Kingdom 3Exploratory Pulsed Power Technologies Branch, Sandia National Laboratories, Albuquerque, NM,
United States
Surface discharges along dielectric components chosen to insulate high-voltage, pulsed-power systems are a problem that can lead to catastrophic failure. Every time a surface flashover or discharge occurs across a component part of a large-scale pulsed-power machine, the output data relating to the shot can also be lost. Knowledge of the electrical fields that can be repeatedly applied to different dielectric materials without resulting in surface flashover or breakdown is therefore important for the appropriate design of insulating components for pulsed-power systems. Impulse voltages of up to 300 kV in magnitude were applied to cylindrical samples of: low-density polyethylene; ultra-high molecular weight polyethylene; polypropylene; Rexolite; and Torlon; via a 10-stage, inverting Marx generator. Breakdown was studied under both uniform- and non-uniform-field conditions, with samples located between a pair of electrodes immersed in insulating oil. Different sample topologies were investigated to determine the effect on the surface-discharge/breakdown field. Previous results, where breakdown occurred on the falling edge of the applied pulses after a variable delay time, indicated that polypropylene had the highest applied field of ~630 kV/cm to initiate breakdown under uniform-field conditions. For the present study, the Marx generator was configured such that the rise-time of the applied impulses was ~1 µs, resulting in breakdown occurring on the rising edge of the pulse. The results presented will provide comparative data for system designers for the appropriate choice of dielectric materials to act as insulators for high-voltage, pulsed-power machines.
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01P-15: A New Method for Electrical Tree Propagation in Solid Dielectrics
M. Talaat1, A. El-Zein2, M. El Bahy3 1Electrical Power and Machines, Ph. D. Student,
Zagazig, Egypt 2Electrical Power and Machines, Professor,
Zagazig, Egypt 3Electrical, Professor, Sinai, Egypt
In the propagation of electrical tree growth behavior in solid dielectrics under operating voltages, one must consider the effects of mechanical stresses, electrical field stresses and the voids distribution to the electrical tree growth. In this study a general model of electrical tree propagation is firstly proposed by using a hyperbolic needle- to plane gap, with needle radius 5μm and gap spacing 1mm, depend on voids location in the polymer, by using Poisson randomly distribution function, combines both the mechanical stresses and the electrical field distribution in the medium, and enables this effect of compressive to predict the electrical tree dynamic growth. The obtained results have been assessed through comparison with available experimental data.
01P-16: Runaway Electrons Preionized Diffuse Discharges at High Pressure
V. F. Tarasenko, E. H. Baksht, A. G. Burachenko, I. D. Kostyrya, M. I. Lomaev, D. V. Rybka High Current Electronics Institute, Tomsk,
Russian Federation
Breakdown of the gaps with a non-uniform electric field filled with nitrogen and air as well as with other gases under high-voltage nanosecond pulses was investigated. It is shown that conditions of obtaining a diffuse discharge without a source of additional ionization are extended at the voltage pulse duration decreasing. A volume discharge is formed due to the gap pre-ionization by runaway electrons and X-ray quanta. At a negative polarity of the electrode with a small radius of curvature, a volume (diffuse) discharge formation is determined by pre-ionization with runaway electrons which are generated due to the electric field amplification near the cathode and in the gap. At a positive polarity of the electrode with a small radius of curvature, the X-ray radiation, generated at the runaway electrons braking at the anode and in the gap, is of great importance in a volume discharge formation. A runaway electrons preionized diffuse discharge (REP discharge) has two characteristic stages. In the first stage, the ionization wave overlaps the gap during a fraction of a second. The discharge current is determined by the conductivity current in the dense plasma of the ionization wave and the displacement current in the remaining part of the gap. The second stage of the discharge can be related to the anomalous glow discharge with a high specific input power. During the second stage, the gap voltage decreases and the cathode spots formed as a result of explosive electron emission can participate in the electron emission from the cathode. At the increase of the voltage pulse duration and specific input power, the REP discharge transforms into a spark discharge form. A REP discharge is easily realized in various gases and at different pressures. At pressure decrease was obtained the anode electrons beam current to rise (up to ~2 kA/cm2 in helium). At the REP discharge, the anode is influenced by the plasma of a dense nanosecond discharge with the specific input power up to hundreds of megawatt per a cubic centimeter, by the electrons beam, shock wave and optical radiation from discharge plasma of various spectral ranges, including UV and VUV. This allows forecasting the REP discharge application for modification and cleaning of metal and dielectric surfaces. The REP discharge is promising as well for creation of the VUV-range excilamps with a high radiation power in a pulse.
191
01P-17: DC Electrical Breakdown of Water in a Sub-Micron Planar Gap
C. Song, P. Wang ECE, Clemson University, Clemson, SC, United
States
Water breakdown subjected to uniform DC electric field in 300 nm planar gaps is experimentally studied. Test devices with microstrip line configurations are fabricated through nanofabrication technology and the results show that water breakdown occurs at ~ 100 kV/cm electric field under current system setup. The initiation process of water breakdown in a small gap is discussed. It is most likely being initialized by pre-existed bubbles or bubbles generated from electrolysis of water. Electrode surface roughness is examined and its effect on observed water breakdown is investigated. Therefore, the process for electrode fabrication needs to be carefully chosen and the fabrication procedures need to be optimized to provide smooth surfaces without sharp tips or micro protrusions in future water breakdown investigations.
01P-18: Evaluation of Magnetic Insulation in SF6 Filled Regions
T. L. Houck, T. J. Ferriera, D. A. Goerz, J. B. Javedani, R. D. Speer, L. K. Tully,
G. E. Vogtlin Lawrence Livermore National Laboratory,
Livermore, CA, United States
The use of magnetic fields perpendicular to quasi-static electric fields to deter electrical breakdown in vacuum, referred to as magnetic insulation, is well understood and used in numerous applications. Here we define quasi-static as applied high-voltage pulse widths much longer than the transit time of light across the electrode gap. For this report we extend the concept of magnetic insulation to include the inhibition of electrical breakdown in gases. Ionization and electrical breakdown of gases in crossed electric and magnetic fields is only a moderately explored research area. For sufficiently large magnetic fields an electron does not gain sufficient energy over a single cycloidal path to ionize the gas molecules. However, it may be possible for the electron to gain sufficient energy for ionization over a number of collisions. To study breakdown in a gas, the collective behavior of an avalanche of electrons in the formation of a streamer in the gas is required. Effective reduced electric field (EREF) theory, which considers the bulk properties of an electron avalanche, has been successful at describing the influence of a crossed magnetic field on the electric field required for breakdown in gases; however, available data to verify the theory has been limited to low gas pressures and weak electronegative gases. High power devices, for example explosively driven magnetic flux compressors, operate at electrical field stresses, magnetic fields, and insulating gas pressures nearly two orders of magnitude greater than published research for crossed fields in gases. The primary limitation of conducting experiments at higher pressures, e.g. atmospheric, is generating the large magnetic fields, 10s Tesla, and electric fields, >100 kV/cm, required to see a significant effect. In this paper we describe measurements made with a coaxial geometry diode, form factor of 1.2, operating at peak electrical field stress of 220 kV/cm, maximum magnetic field of 20 Tesla, and SF6 pressure of 760 torr. Information on the design considerations and performance of the measurement apparatus is provided. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
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01P-19: Registration of Initial Stage of Air Breakdown in the Fields of Subgigawatt
Ka-Band Microwave Pulses M. I. Yalandin1, A. G. Reutova1, K. A. Sharypov1,
V. G. Shpak1, S. A. Shunailov1, M. R. Ulmasculov1, G. A. Mesyats2
1Institute of Electrophysics, Ural Branch of Russian Academy of Sciences, Ekaterinburg,
Russian Federation 2Lebedev Physical Institute RAS, Moscow,
Russian Federation
Initial stage of breakdown of atmospheric air in the fields of Ka-band pulses was recorded with the rise of microwave power up to the maximum value at characteristic time of ~300 ps. Microwave pulses were generated by relativistic BWOs, possessing an output peak power of ~170 MW and ~500 MW (FWHM: 4 ns and 300 ps, respectively). The effects of air breakdown in the fields of such pulses are essential with extraction of radiation through vacuum window of horn-type antenna; with canalization of radiation in the waveguides and quasi-optical transmission lines. Of special interest is the case, when HPM pulses are generated in repetitive regime. In the experiments it was shown that appearance of microwave breakdown corresponds in general to the rise of electrical strength of air with the time scale decrease down from units of nanosecond. It was demonstrated, that the lag of breakdown development makes it possible to ensure irradiation and canalization of a single, subnanosecond HPM pulses without shortening and essential losses of energy. On the other hand, an increase of exposure time of even a single, short microwave pulse at a certain critical level of electric field leads to appearance and build-up of cutting effect. Propagation of powerful microwave pulse produces somewhat ionizing background, and, hence, a subsequent incoming pulse undergoes more essential absorption. This effect was observed also in oversized circular waveguide for 300-ps long HPM pulse by method of reflectometry with a 2-ns delay of the second propagating pulse. In the case of FWHM~4 ns the microwave absorption was dramatic at a pulses repetition interval up to 1 s, and exhibited an obvious enhancement of the pulse cutting for each sequential pulse (buildup effect). Development of air breakdown distorts an envelope of irradiated power recorded by microwave detector. Actually, understating of the HPM pulse width becomes probable. This can lead to overestimation of HPM peak power, determined from the results of accompanying energy measurements of microwaves by vacuum calorimeter. Therefore with the durations of HPM generation of ~1 ns and shorter the question of identification of breakdown thresholds in the air acquires a special importance.
Work supported by Russian Foundation for Basic Researches. Grant 08-02-00183 and Grant 08-02-01059.
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01P-20: The Influence of a DC Electric Field on High Power Microwave Window Flashover in Air and N2 Environments* J. Foster, M. Thomas, H. Krompholz, A. Neuber Center for Pulsed Power and Power Electronics,
Department of Electrical and Computer Engineering, Texas Tech University, Lubbock,
TX, United States
Observed delay times for high power microwave surface flashover are influenced significantly by the presence of a DC electric field. The experimental setup to investigate theses influences uses an S-band magnetron operating at 2.85 GHz, which outputs a 4 MW, 3μs pulse through a WR-284 waveguide towards a plasma switch reducing the pulse rise time from ~600 ns to ~50 ns. The switch reflects this fast-rising pulse through a 4-port circulator towards a dielectric window where surface flashover is observed. A wire electrode charged to ±20 kV is inserted into the dielectric interface perpendicular to the electric field of the TE10 mode to provide a DC electric field in the flashover region. Tests have been conducted in pure N2 at 125 torr in order to provide an environment composed of primarily electrons and positive ions, without the presence of negative ions as expected in air. The average measured delay of window flashover with a DC field pointing into the dielectric has been observed to increase by ~50%. Additionally, effective emission rates of seed electrons causing breakdown have shown a decrease from 14 e/μs to 2 e/μs for this configuration, indicating the removal of charged species from the high microwave field region due to charge drift in the applied DC field. An overview of the experimental setup is given along with a statistical analysis of delay times measured in Air as well as N2. The open question of where seed electrons originate from and the quantification of the primarily processes involved will be addressed. * This work was solely funded by the Cathode and HPM Breakdown MURI program funded and managed by the Air Force Office of Scientific Research (AFOSR).
01P-21: Helical Antennas for High Powered RF
J. R. Mayes, M. G. Mayes, W. C. Nunnally, C. W. Hatfield
Applied Physical Electronics, L.C., Austin, TX, United States
Radiating high power RF below 1 GHz can be difficult. Large structures are preferred for high voltage operation; however, large structures are difficult to deploy. Conversely, small geometries are more easily deployed, but insulating the high voltage can be difficult. Dipole structures have made their way into use due to thei relatively simple and compact implementation; however, their radiation pattern is not desirable, since they radiate in a donut pattern, which can disrupt, or even destroy one's own electronic controls. Impulse Radiating Antennas have been configured for wideband operation; however, their large geometry is very difficult to deploy. Helical antennas offer many advantages over other methods. The helical antenna is relatively compact, with its cylindrical geometry. The antenna's geometry is wavelength dependent, but is acceptable from several hundred MHz and higher, with the upper limit being dominated by the high voltage operation. It offers a good gain factor and can be operated as a narrow band, or wide band device. Applied Physical Electronics, L.C. has been developing high voltage helical antennas for narrow band and wide band applications. This paper describes the fundamental operation of the helical antenna. Simulation and experimental results are provided.
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01P-22: A Marx Generator Driven Impulse Radiating Antenna
T. A. Holt Applied Physical Electronics, L. C., Austin, TX,
United States
APELC has developed an Impulse Radiating Antenna (IRA) that consists of a TEM-horn-fed parabolic reflector that is directly driven by a 22-J, 400-kV Marx generator. The system is based off of standard Marx generator designs offered by APELC. The Marx generator output couples directly to the TEM horn via a transition from a coaxial geometry that approximates a standard coaxial-to-parallel plate transition. Main design considerations that facilitate achievement of high instantaneous radiated power include appropriate Marx generator risetime, transition design, and TEM horn focal point positioning. Data collected over the course of the system design is presented.
01P-23: Ultrawideband Antennas for Imaging in the near Field
S. Xiao1, M. Migliaccio1, J. T. Camp1, C. Baum2, K. H. Schoenbach1
1Old Dominion University, Frank Reidy Research Center for Bioelectrics, Norfolk, VA, United
States 2University of New Mexico, Department of
Electrical and Computer Engineering, Albuquerque, NM, United States
The use of prolate-spheroidal reflectors as part of a sub-nanosecond Impulse Radiating Antenna (IRA) allows us to generate electric fields with high spatial resolution in the near field of the antenna [1,2,3]. The IRA can serve as part of an ultrawideband imaging system to probe electrical inhomogeneities in a biological target [4]. In addition, with high-power sub-nanosecond electrical pulses at high repetition rates, it becomes possible to deposit substantial electromagnetic energy into a biological target, which might allow local hyperthermia or even allow us to stimulate nonthermal effects in biological cells. The impulse radiating antenna consists of a conical wave launching system and a prolate spheroidal reflector. The TEM spherical wave emitted from F1 is reflected on the prolate spheroidal reflector surface to converge at the second focal point (F2). The reflector has an aperture diameter 14.4 cm, and the distance between the two foci is 24.1 cm. The antenna is submerged in a liquid medium which allows to better match the tissue permittivity. Tissue (relative) permittivities range from 10 for adipose tussue to 50 for muscle tissue. While this antenna due to its operation in high permittivity media has a relatively small aperture diameter, we are simultaneously working with a reflector antenna [3] with a larger aperture diameter of 0.5 m which is operated in air. The antenna also uses a prolate spheroidal reflector, but with a symmetrical conical arm feeds (either 4 or 2 arms) extended from the first focal point to the reflector. A balun is being used to suppress the common mode signal. The electric field distribution along the axis of the rotationally symmetric antenna from the reflector edge to the optical focal point of the spheriodal reflector was recorded for a monopolar excitation pulse with a FWHM width of 240 ps. Also recorded was the radial distribution of the electric field at the focal point position. The results obtained with a wideband pulse were compared to those obtained with narrowband radiation at 1.5 GHz and 0.9 GHz. The experimental results were compare to modeling results using MAGIC, a 3-D EM solver [5]. Acknowledgement: This work has been supported by AFOSR and by Bioelectrics Inc., VA.
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[1] K. Hirasawa, K. Fujimoto, T. Uchikura, S. Hirafuku, H. Naito, “Power Focusing Characteristics of Ellipsoidal Reflector,” IEEE trans. A.P., 32 (10), 1033-1039, 1984. [2] S. H. Kim, K. W. Chen and J. S. Yang, “Modal Analysis of Wake Fields and Its Application to Elliptical Pill-box Cavity with Finite Aperture,” J. Appl. Phys., 68 (10), p. 4942, 1990. [3] C. E. Baum, “Focal Waveform of a Prolate-spheroidal IRA”, 42 (6), Radio Science. [4] S. Xiao, C. E. Baum, and K. H. Schoenbach, “Near-Field Imaging of Tumor Tissue with Sub-Nanosecond Electrical Pulses”, this conference. [5]http://www.mrcwdc.com/magic/index.html.
01P-24: Numerical Simulations of an Inverted Magnetron
T. P. Fleming Directed Energy Directorate, Air Force Research
Lab, Albuquerque, NM, United States
An Inverted Relativistic Magnetron configuration consisting of either a twelve or fourteen vane slow wave structure is investigated using the three-dimensional electromagnetic particle in cell code ICEPIC. Several design features of the inverted magnetron make it an attractive alternative to the standard relativistic magnetron; among these are larger cathode surface area and a reduction in downstream loss current. However, a reduction in the desired resonant RF phase velocity requires the slow wave structure to possess an unusually large vane count relative to the standard design. The large vane count supports many more possible modes, leading to mode competition and mode lock-in problems which significantly impede output power and efficiency. Moreover, the method by which electromagnetic energy is extracted from the magnetron may also influence what modes are favored. Our ICEPIC simulations show that these performance problems may be mitigated by the introduction of small perturbations in the cathode surface. These perturbations prime the diode electric field such that a DC azimuthal electric field component, Eθ, is introduced within the electron hub region. This azimuthal field component in turn hastens the capture of electrons into spokes and initiates oscillations, as well as reducing mode competition. Additionally several of our simulations have employed straps, which electrically connect alternating vanes to favor π mode oscillations and reduce mode competition. Finally, several downstream power extraction configurations are examined. These configurations are designed to excite a TE11 mode past the extraction slots.
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01P-25: A Versatile and Mobile L-Band High Power Microwave Systems
M. U. Karlsson, M. E. Jansson, F. Olsson, D. Åberg
Applied Physics, BAE Systems Bofors AB, KARLSKOGA, Sweden
The BAE Systems Bofors new mobile High Power Microwave system has proved itself very suitable for research and evaluation of microwave effects in the L-band. The system is composed of a high voltage modulator, a microwave source, a conical horn antenna and an adjoining vacuum system. An integrated battery supply makes the system operational in all terrains and independent of standard laboratory utilities. The total weight of the system is less than 500 kg and the length is just above two meters. The system is capable of generating GW-levels of microwaves and with minor modifications the frequency could be changed well into the S-band without too much loss in power. A typical antenna gain for the system is 15-25 dBi.
01P-26: Analytical Calculation of Anode Current in Relativistic Magnetron
A. D. Andreev1, M. I. Fuks2, K. J. Hendricks1, E. Schamiloglu2
1Directed Energy Directorate, Air Force Research Laboratory, Kirtland AFB, NM, United States
2ECE, University of New Mexico, Albuquerque, NM, United States
An analytical expression for calculation of the anode current of a relativistic magnetron is derived using a method originally developed in [1]. The anode current is described as the cathode-to-anode drift of the electron guiding centers in the crossed magnetic and induced rf electric fields. To derive the expression for the anode current, the cylindrical geometry of a magnetron is approximated by a planar model and the drift of the electron guiding centers is analyzed in the frame of reference moving with the phase velocity of the induced rf electric field. Drift of the electron guiding centers from the cathode to the anode is analyzed using a zero-space-charge approximation. The anode current determined by this drift is calculated under an assumption that the cathode operates in a space-charge-limited mode, when the external electric field at the cathode surface is zero. Results of the calculations are compared with computer simulations of the anode current of the A6 relativistic magnetron with increased cathode-anode gap and anode radius [2]. This magnetron is able to operate in stable π-mode, in a broad range of applied voltages and magnetic fields, in a frequency range of 2.7-2.8 GHz. Simulations of the magnetron operation are performed using the ICEPIC code. Analyses of the obtained results show rather good agreement between analytics and simulations at intermediate voltages and magnetic fields. The slight disagreement at high voltages can be explained by a number of simplifying assumptions made during development of the analytical expression: plane model of the magnetron, zero-space-charge approximation, etc. There are also the 3-dimensional effects that affect the agreement between analytics and simulations: increased magnetic field additionally created by the cathode current of the magnetron, axial spread out of the rotating electron flow that increases effective cathode area, etc. [1] V. E. Nechaev, A. S. Sulakshin, M. I. Fuks, and Yu. G. Shtein, "Relativistic Magnetron," in Relativistic High-Frequency (Microwave) Electronics, Proceedings of All-Union (USSR) Conference, Gorkiy, 26-28 September, 1978, Institute of Applied Physics, USSR Academy of Sciences, pp. 114-129, 1979. [2] R. W. Lemke, T. C. Genoni, and T. A. Spencer, "Three-dimensional particle-in-cell
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simulation study of a relativistic magnetron," Physics of Plasmas, Vol. 6, No. 2, February 1999, pp. 603-613. ___________ Andrey D. Andreev is currently the NRC Post-Doc at AFRL, Albuquerque, NM
01P-27: Electric Field Distributions in the Cross-Sections of the SIC Hollow-Core
Waveguides S. Asmontas1, L. Nickelson1, T. Gric1,
R. Martavicius2 1Terhertz's Electronic Laboratory, Semiconductor
Physics Institute, Vilnius, Lithuania 2Electronic System Department, Gediminas
Technical University, Vilnius, Lithuania
The SiC material can be used in wide area of applications. Silicon is the material that dominates the electronics industry today. A change of technology from silicon to silicon carbide is going to revolutionize the power electronics. So the SiC power devices are beginning to be commercialized nowadays [1]. Hollow-core (HC) waveguides have a wide range of excellent properties. For example, HC waveguides enjoy the advantages of high laser power, no end reflections and small beam divergence [2]. We have investigated HC cylindrical SiC waveguide. The investigations were made at different temperatures (T=200C, 12500C, 15000C, 18000C). The complex permittivity of the SiC material depends on the temperature. The complex permittivity values were taken from [3]. We have calculated the dispersion characteristics of the main and several higher modes of the HC SiC waveguides with different radiuses. We have also calculated the electric and magnetic field distributions in the cross-sections of these waveguides. Our calculations show that the field distributions and losses of the HC waveguides are very different dependent on the temperature. References: [1] A. Agarwal, S.-H. Ryu, Status of SiC Power Devices and Manufacturing Issues, CS MANTECH Conference, 24-27 April 2006, Vancouver, British Columbia, Canada, p. 215-218, 2006. [2] H. Jelinkova, M.Nemec, J.Sulc, P. Cerny, M. Miyagi, Y.-W. Shi, Y. Matsuura, Review. Hollow wave delivery systems for laser technological application, Progress in Quantum Electronics, Vol. 28, No. 3-4, p. 145-164, 2004. [3] T. A. Baeraky, "Microwave Measurements of the Dielectric Properties of Silicon Carbide at High Temperature", Egypt. J. Sol., Vol. 25, No. 2, p. 263-273, 2002.
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01P-28: PIC-Simulation of Highly-Effective, Non-Stationary Relativistic 70-
GHz BWO M. I. Yalandin1, V. G. Shpak1, V. P. Tarakanov2,
S. V. Zhakov3 1Institute of Electrophysics, Ural Branch of
Russian Academy of Sciences, Ekaterinburg, Russian Federation
2High Energy Research Centre of Russian Academy of Sciences, Moscow, Russian
Federation 3Institute of Metal Physics, Ural Branch of
Russian Academy of Sciences, Ekaterinburg, Russian Federation
In the last decade we have made a number of simulations of quasi-stationary and nonstationary subgigawatt-power relativistic backward wave oscillators (BWO) operating in the millimeter band. In the frequency range of 38 GHz data of PIC- simulations [1] were confirmed in the experiments [2] with accuracy not worse than 10-20%. The present work demonstrates the results of full-scale numerical PIC-simulation of nonstationary BWO designed for the frequency band of ~70 GHz. This is an oscillator with predicted duration of microwave pulse of ~150 ps and an output peak power of up to 0.4 GW. Quasi-stationary option of similar powerful 70-GHz BWO with elongated HPM pulse could be of interest in the further experiments for producing a sub-terahertz radiation spikes by the method of backward scattering of pumping wave by relativistic electrons in superradiative regime [3]. In the report we will present the following: (1) Test results of pulsed generators of accelerating voltage pulses. (2) Simulation of the accelerating voltage pulse delivery to the e-beam injector. (3) PIC modeling of e-beam formation in accelerating diode. (4) Preliminary BWO simulation based on similarity laws. (5) Simulation of the BWO generation with the e-beam diode of real geometry and Bz-field interpolation. (6) Selection of the guiding pulsed solenoid profile providing an adequate B-field interpolation. Calculation of the pulsed solenoid supply source. (7) Final PIC-simulations of the BWO equipped with a real-geometry e-beam diode, pulsed solenoid coil and electrodynamic slow-wave structure. (8) Prospective BWO PIC-model equipped with magnetic focusing system based on high-coercive permanent magnets. Work supported by Russian Foundation for Basic Researches. Grant 07-08-00772 and Grant 08-02-01059.
REFERENCES [1]. V.P. Tarakanov, User's Manual for Code KARAT, Berkeley Research Associates, Inc., VA, USA, 1992. [2]. M.I. Yalandin, V.G. Shpak, V.V. Rostov Compact relativistic millimeter-band microwave oscillators, Izv. Vuzov, Fizika, vol. 49. no.11, Supplement, pp.450-453, 2006. [3]. V. Shpak, M. Yalandin, G. Denisov, N. Ginzburg, Backward scattering of high-power microwaves by subnanosecond relativistic electron beam, Digest of Tech. Papers of the 15-th IEEE Int. Pulsed Power Conf., Monterey, CA,USA, 13-17 June 2005, P.186-189.
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01P-29: Peculiarities of Transient Processes in Relativistic Backward-Wave
Oscillators and Amplifiers A. Konyushkov, E. Abubakirov, A. Sergeev Russian Academy of Sciences, Institute of
Applied Physics, Nizhny Novgorod, Russian Federation
One of essential features of high-current relativistic electron beams, employed in high power microwave generators and amplifiers is their short duration. As a rule its value does not exceed tens of nanoseconds, that means several hundreds (or even less) of high-frequency field oscillation periods. Hence, the problem of minimizing transient times in relativistic microwave generators is among the most important ones. In the report we performed an analysis of transient processes in relativistic backward-wave oscillator (BWO), while special attention was drawn to analysis of high-frequency noises of electron beam and peculiarities of the BWO operation near excitation threshold. It was found, that the main reason for high-frequency noises of electron beam is employing explosion emitted injectors. Electrons in explosion emitted beams are injected from separated areas of cathode plasma, and the beam consists of numerous electron packets, called ectons. Due to random time of a single ecton origination and its low duration (5-10 ns), the explosion emitted beam has a noise term similar to shot-noise of conventional electron tubes. Simulations showed that in case of backward-wave beam noises do not have any significant effect on a steady-state operation of the device, but determine oscillations start-up time. Transition times found in accordance to this theory are of the same order as experimental results. At the same time high frequency noises produce an essential effect on BWO-amplifiers with low input signal. The report contains the analyses of minimum level of input signal, when amplification regime is still possible. Possibility of hard excitation is another peculiar feature of relativistic BWOs with high efficiencies. The analysis of transient processes of relativistic BWO showed that operation in hard regime (or close to that) gives possibility to realize short oscillation rise-time and reach a stable and efficient operation of the device at small exceeding of the self-excitation threshold. Actually, the possibility of hard excitation of the BWO is more significant for the amplifying version of the device. Utilization of a backward-wave amplifier, operating, operating in regime of regenerative amplification near threshold of its self-excitation, is very profitable because it allows one to achieve high amplification and reduce the
influence of electron beam noises by narrowing amplification frequency band. Obviously, external signal can force the BWA to self-oscillation, if its parameters lay near the boundary of area, where the hard excitation exists. Effect of hard excitation strongly limits maximum level of input signal and prevents from achieving high gain in the amplifier. The report presents results of theoretical research of various versions of relativistic backward wave regenerative amplifiers, and discussion on manifestation of hard oscillations in such regimes.
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01P-30: Effects of Coupling Conduct in Phase Matching of Parallel Virtual
Cathode Oscillators S. S. M. Chung1, 2, T. I. Tzeng3, H. Y. Lin4,
S. H. Cheng5, T. W. Suen6 1Department of Electronics Engineering,
Southern Taiwan University of Technology, Tainan, Taiwan
2Center for Micro/Nana Science and Technology, National Cheng Kung University, Tainan, Taiwan
3Computational Application Division, National Center of High-performance Computing, Hsinchu,
Taiwan 4Mechanical and System Research Laboratory,
Industrial Technology Research Institute, Hsinchu, Taiwan
5Institute of Nuclear Energy Research, Atomic Energy Commission, Taoyuan, Taiwan
6Electronic Research Division, Chung-Shan Institute of Science and Technology, Tauyuan,
Taiwan
Current high power microwave (HPM) system faces two major challenges: field emission breakdown field limits on waveguides and windows and pulse width shortening in source and windows; a possible solution would be consecutively firing of multiple sources. Virtual cathode oscillator (Vircator) is known for low efficiency (3-5%), short pulse (10-50 ns), and low stability (current fluctuation ~10-30%) depending on cathode materials, single or double opposing-fired, or pre-modulated electron beam designs, how ever, Vircator is still the only device capable of multi-GW output without heavy magnets and complicated cooling systems, therefore suitable for multiple sources device. Early experiment of H. Sze et al. on phase locking of two strongly coupled Vircators suggest mode control and output combination through this scheme is possible, where as some parametric relations are yet to identified. We explore this arrangement with MAGIC simulation, with variables in coupling conduct length and width, which affect the electric field distribution and modes. Preferred conduct length would be multiples of main resonant wavelengths.
01P-31: Optimization of the Energy Efficiency for a Coaxial Vircator M. U. Karlsson, F. Olsson, D. Åberg,
M. E. Jansson Applied Physics, BAE Systems Bofors AB,
KARLSKOGA, Sweden
This paper describes the experimental results from an optimization work done on a coaxial vircator. The microwave source is driven by a Marx generator and excludes any type of pulse forming device between the two subsystems. There are two main reasons for not including any pulse forming device. The first is the final goal to build an extremely compact and robust high power microwave system. The second reason is to get as high energy efficiency as possible from the system, calculated as the ratio between the output microwave energy and the stored energy in the Marx generator. The vircator operates with an applied maximum voltage of close to 400 kV and the impedance is around 25 Ohms during the process when the main part of the microwave radiation is generated. The microwave pulse is for most of the cases as long as 400 ns. For the experiments described in this paper focus has been on variations in the axial geometry and on different emitter materials. Results that are given include microwave power, spectral content, mode characteristics and energy efficiency. In an attempt to better understand and explain the experimental results particle-in-cell simulations have been carried out in MAGIC.
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01P-32: High Power S-Band Microwave Radiation from Small Body Waveguides
E. C. Becker, S. D. Kovaleski, J. M. Gahl University of Missouri-Columbia, Columbia, MO,
United States
High power microwave radiation in the S-Band is currently being studied in small body waveguides. Waveguide structures are currently being developed that transmit high power microwaves in the S band from the TE11 mode into high gain, highly directive radiation patterns. Using advanced modeling techniques, the behavior of these high power electromagnetic waves can be accurately described inside the waveguide as well as in the near and far field regions, which in turn, improves the quality of high power experiments performed on the waveguide. Presented are the modeling results of high power electromagnetic waves in the small body waveguide. Plans for an S-Band microwave experiment are also discussed.
01P-33: Large Signal Analysis of Ring-Bar Slow-Wave Structures for Ku-Band
Traveling-Wave Tubes D. T. Lopes1, C. C. Motta2
1Nuclear & Energetic Research Institute, Sao Paulo, Brazil
2University of Sao Paulo, Sao Paulo, Brazil
This work deals with the investigation of possibilities of using ring-bar slow-wave structures (SWS) in medium-high power traveling-wave tubes (TWT) for the Ku-band (13.7514.5GHz). Ring-bar SWSs are often used in high (pulsed) power TWTs for narrow band purposes. Its main advantages over the single helix are a higher interaction impedance (roughly twice) and a good rejection factor to the backward mode. The main drawback of this kind of SWS is a higher dispersion profile that limits its bandwidth. Additionally, ring-bar SWSs are faster and have higher upper cutoff frequency than single helices. These features implicate in a larger SWS diameter if compared to a single helix in the same frequency, making the fabrication of the interaction circuit easier. The investigation here attempts to verify if this more dispersive SWS, under some dispersion profile linearization techniques (like the use of vanes and dielectric loading), can result in a interaction circuit with acceptable gain profile over the Ku band. The large signal analysis (hot model) is performed by an in house large signal lagrangian code under development and the cold tests are performed with a 3D eigensolver.
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01P-34: RF Generation in a Discrete Element Nonlinear Transmission Line D. M. French1, R. M. Gilgenbach1, Y. Y. Lau1,
J. W. Luginsland2, D. Shiffler3 1Nuclear Engineering and Radiological Sciences,
University of Michigan, Ann Arbor, MI, United States
2NumerEx, Albuquerque, NM, United States 3Directed Energy Directorate, Air Force Research
Laboratory, Albuquerque, NM, United States
Nonlinear transmission lines have been demonstrated to be an effective technique for generating high power ultrawideband or mesoband radiation without the need for a vacuum system, electron beam, or magnet. Preliminary experiments have been performed at AFRL and UM on a discrete element nonlinear transmission line with nonlinear capacitance. Depending on the injected pulse, either pulse sharpening or RF generation could be observed. The differences between these two cases and the threshold for RF generation will be discussed. Time frequency analysis has been applied to analyze the generated RF spectrum. These effects were reproduced in circuit simulations. Results from these preliminary experiments and plans for future high power nonlinear transmission line experiments using LTD technology at UM will be presented. *Research supported by AFOSR and AFRL
01P-35: Numerical Simulations of the Influence of a Reflector in a Coaxial
Vircator C. Möller, T. Hurtig, A. Larsson, S. E. Nyholm Defence & Security, Systems and Technology,
Swedish Defence Research Agency (FOI), Stockholm, Sweden
A vircator (virtual-cathode oscillator) is a narrow-band vacuum cavity oscillator often used as the radiation source in a High-Power Microwave (HPM) system. One possible configuration is the coaxial vircator, in which the anode and cathode are coaxial cylinders, and the inner cylinder serves as the anode. The electrons are emitted from the surface of the cathode, which is made of an electron emitting material, and accelerated towards the anode, usually made of a metal mesh or a metal foil. The electrons continue through the anode and form an electron cloud - the virtual cathode, inside the anode, when the space charge limit is reached. In normal operation, the symmetric TM01 mode is generally radiated. This mode may not, however, be optimal in all applications since it has a nought on boresight. It is possible to excite the more favourable TE11 mode, which has its maximum on boresight, by splitting the emitting surface of the cathode into two sections, thus creating two interacting virtual cathodes. The two virtual cathodes formed oscillate in a push-pull mode. To improve the performance of the vircator, a reflector can be inserted in the waveguide through which the microwave radiation is extracted. Numerical particle-in-cell (PIC) simulations have been performed with both TM01 and TE11 excitation, where the position of the reflector has been changed. The results show a great impact on the radiated power due to the reflector position.
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01P-36: UNIPIC: a Novel Particle-in-Cell Simulation Method for Design of High
Power Terahertz Vacuum Electron Devices
H. Zhang, J. Wang School of Electronic and Information Engineering,
Xi'an Jiaotong University, Xi'an, China
New micromachining techniques now provide us with the technology to fabricate the vacuum electron devices, such as reflex klystron, traveling wave tube, backward wave oscillator, with the dimensions suitable for operation in the terahertz region of the electromagnetic spectrum. For the success of these devices, accurate designs are required since the optimization of certain parameters is critical to obtaining useful amounts of ac power. Classical models for device design have long been in existence, but these are no longer valid at terahertz frequencies. For this reason, a novel computer simulation tool has been developed, especially aimed at the design of terahertz vacuum electron devices. This simulation tool is referred to as “UNIPIC”, which means a combination of Union, Universal and Particle-in-Cell. It is a user-configurable code that solves Maxwell’s equations together with Lorentz particle motion. A variety of 2D, finite-difference electromagnetic algorithms and 3D particle-in-cell algorithms can be combined in problem-specific ways to provide fast, accurate and transient calculations for research and design needs. It is also characterized by many technical improvements. For example, a volume-weighting cloud-in-cell (CIC) model was proposed in this code rather than the area-weighting CIC model in order to enhance the calculation precision in the situations where macro-particles exist near the symmetric axis; another betterment is that a cyclotron and drift correction mechanism was proposed to improve the accuracy of the particle moving algorithms, which could relax the time step limitation and resultantly reduced the total computing time; Other characteristics, such as PML error diffusion method, Monte-Carlo collision consideration as well as main peculiarities expected for devices operation at terahertz frequencies were all taken into account in this new simulation scheme. For its validation of real design, a 140GHz MW-Class relativistic backward wave oscillator was simulated with both UNIPIC and MAGIC (which is a traditional, famous PIC code in HPM field) under the same conditions. The effects of device parameters which are critical to the optimization of output power in this tube based on an explosive electron emission source were also studied. The compared results demonstrated that UNIPIC had the same computation precision as MAGIC and owned the more perfect GUI mechanism for data output. Therefore, it is believed that UNIPIC is a
reliable, practical and promising 2.5D full electromagnetic PIC code, which must ease the complicated design process of high power terahertz devices in future.
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01P-37: Relativistic Resonant TWT with Bragg Reflectors
V. A. Gintsburg1, N. G. Kolganov1, N. F. Kovalev1, M. I. Fuks2, E. Schamiloglu2
1Branch of High-Current Microwave Electronics, Institute of Applied Physics, Nizhny Novgorod,
Russia 2Department of Electrical and Computer Engineering, University of New Mexico,
Albuquerque, NM, USA Results from an experimental study are given for an X-band relativistic resonant traveling wave tube (RTWT) with selective feedback produced by Bragg reflectors. An axisymmetric slow wave structure (SWS) consisting of separate sinusoidal-profile rings each with length equal to one period was used and allowed us to find the threshold SWS length for self-excitation. The optimal length corresponded to the maximum generated power. Long sections with gradually decreasing depth of corrugation were used on both ends of the SWS for matching with reflectors. The Bragg reflectors used had three spiral corrugations and allowed for operation with two combinations of mode: 1) amplification of the HE11-mode with feedback on the TE41-mode at frequency f1 = 10.9 GHz and 2) amplification of the TM01- mode with feedback on the TE31-mode at frequency f2 = 9.12 GHz. One or the other mode combination was realized by mutual rotation of the reflectors. Variation in the mutual phasing of the reflectors changes the length of the feedback circuit that shifts the resonant frequency within the Bragg stop-bands, giving preference to one mode combination or the other. A Gaussian radiation pattern corresponded to the first mode combination and the radiated power achieved was 1.5 GW (both polarizations are present) when the SWS length Lsws = 28d, the applied voltage V = 1.1 MV, electron beam current I = 6.5 kA and relation of the electron beam radius Rb to the minimal SWS radius Rb/R = 0.75 (Rb was limited by the input diaphragm to protect the SWS from electron bombardment although radiation power quickly rises with increasing beam radius). The power was measured a distance 5.2 m from the horn antenna with a 28 cm aperture. This result was obtained when the guide magnetic field exceeded the region of cyclotron absorption of the feedback mode. It is interesting to note that for the axial magnetic field polarized in one direction, only the radiation pattern with the maximum power at the center is observed and its intensity weakly depends on the rotation of the reflectors. When the axial magnetic field is polarized in the opposite direction the radiation pattern changes from a Gaussian beam to a pattern with a deep minimum at the center corresponding to radiation of the TM01- mode. Replacement of these reflectors with Bragg reflectors with five-spiral
corrugations eliminates radiation of the TM01- mode. Dependencies of RTWT operation on the parameters of the electron beam, length of the interaction space, reflection coefficients, and guide magnetic field are investigated in detail. This oscillator demonstrated operation with great stability from one shot to the next.
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01P-38: Experimental Investigation of the Relativistic Cherenkov Microwave
Oscillator Without a Guiding Magnetic Field
E. M. Totmeninov, A. I. Klimov, V. V. Rostov Siberian Branch RAS, Institute of High Current
Electronics, Tomsk, Russian Federation
Research and development of relativistic microwave generators without an external magnetic field are of interest for some applications. Absence of the external guiding magnetic field is the most important because this allows for avoiding the energy consumption for the magnetic field creation. The energy consumption can be very high in repetitively pulsed mode of the generators. Examples of such devices are, vircator, MILO, Relativistic cherenkov microwave oscillator without a guiding magnetic field. This paper presents the results of experimental investigation of the Relativistic cherenkov microwave oscillator. In this generator, a solid cylindrical relativistic electron beam is formed in a planar diode and propagates through a resonant slow wave system without external magnetic field. Transportation of the electron beam in the drift tube uses the azimuthal component of the self magnetic field, which prevents the beam divergence under the action of the self space charge. Slowing down of the traveling wave to the light speed enables efficient interaction of the wave with the solid cylindrical relativistic electron beam. In this case the distribution of the electric field longitudinal component of the fundamental harmonic over the slow wave system cross-section is nearly uniform. Preliminary modulation of the electron beam at the entrance of the slow wave system provides the condition for efficient energy exchange at the phase velocity of synchronous wave a bit higher than the electron velocity. The efficiency as high as 25 – 40% of the device for the electron energies 0.5 – 1 MeV was predicted in the simulations with the used PIC code KARAT. In the experiments the solid cylindrical relativistic electron beam was formed in the planar diode that included the anode mesh and cathode that was placed inside a focusing stainless steel electrode. The mode TM01 generation was observed with an efficiency of 10 ± 2 % taking into account the total vacuum diode current at the electron energy 1 MeV. The microwave peak power was 1.3 ± 0.3 GW at the oscillation frequency of 4.03 GHz. The energy of the microwave pulse measured using aperture calorimeter was 13 ± 1 J. The microwave pulse width was about 11 ns. For some pulses the peak microwave power reached 1.5 ± 0.3 GW with 12 ± 2 % efficiency. The transmitted current measured just behind the anode mesh was about 50% of the total diode current. Thus, the
efficiency of the device was about 20 % taking into account the transmitted current. The regime was realized with an efficiency of 5 ± 1 % for the electron energy 0.5 MeV. The average microwave peak power was 0.1 ± 0.02 GW at the oscillation frequency of 3.9 GHz. The energy of the microwave pulse measured using aperture calorimeter was 1.5 ± 0.5 J. The microwave pulse width was about 20 ns. An attempt of the repetitively pulsed mode of the generator was made in this work.
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01P-39: Pulse Power Technology Challenge of High-Current Secondary
Emission Magnetron Injection Gun S. Cherenshchykov
National Science Center, Kharkov, Ukraine
The design and the principle of a cold cathode magnetron gun operation in a secondary emission mode are described briefly. There are reported characteristic properties and advantages of such device in comparison to known conventional devices for generating of electron flows in vacuum. These advantages are the simplicity of the device, durability, the good repeatability of pulses and their driving. Besides, the gun is differed by energetic efficiency due to the absence of a cathode heating and by environmental purity due to long life time and to the absence of detrimental and non-utilized materials. Self-sustained secondary emission from metallic cathode being the operating principle of the gun permits to increase easily total current, pulse duration and pulse repetition rate. Avalanche emission on a voltage pulse decay permits to achieve a switching time of 10-9 seconds according to experiments and up to 10-11seconds according to theoretical estimations. The gun current may be varied from 10-2 A up to 5*103 A depending on the voltage of 4*103-8*105 V applied to guns of different designs. According to experimental results the pulse duration may be varied in the range 10-9-10-2 seconds at the pulse repletion rate up to 50 Hz. There are reported the ranges of parameters of different gun designs achieved recently. The expression for the gun beam current calculation was deduced based on the method of scaling simulation. Examples of the gun application are enumerated including the tested experimentally. The resent achievements and the prospects for the development are discussed in the report. The research of high current sample of the gun is supported by the governments of USA and Canada through the intergovernmental fund STCU in frame of the project #1968 «HIGH-CURRENT ELECTRON GUN WITH SECONDARY EMISSION».
01P-40: MAGIC3D Electromagnetic FDTD-PIC Code Dense Plasma Model
Benchmark A. J. Woods, L. D. Ludeking
Mission Systems, Alliant Techsystems (ATK), Newington, VA, United States
BACKGROUND: For more than 2 decades, the MAGIC electromagnetic (EM) finite difference time domain particle-in-cell (FDTD PIC) code [1] has had air ionization dense plasma models similar to those in the Lsp code [2]. Lsp has been applied to a number of EM plasma investigations in recent years (e.g. [3]). MAGIC users have also lately modeled gas plasmas. Correlation of the models with the more recently-developed Lsp code was considered prudent. INTRODUCTION: MAGIC FDTD PIC EM code responses computed using the dense plasma model have been recently compared with Lsp for 2D problems [4]. Excellent agreement of the tools was achieved using simple geometric representations of generic electron beam chamber experiments. Validation of the models in total was demonstrated based on the zone-by-zone travelling plasma breakdown of the electric fields. The subsequent transition to magnetic field determination of electron trajectories stressed every core aspect of the codes. This paper will present the results of the straight-forward implementation of the core models in the MAGIC3D code. AIR PLASMA MODEL: Air ionization is caused by primary and secondary electrons. Primaries are the energetic beam particles and secondaries are the low energy ionization products which also ionize neutrals. Processes of electron attachment to neutrals, recombination with ions, and neutralization of ions are included. The plasma is driven primarily by the ratio of the electric field to the air pressure. The applied electric field causes an conductivity which is applied on a cell-by-cell basis to the Maxwell’s equations. ELECTRON BEAM TESTS A large pinched electron beam test is performed in a cylindrical cavity. The current density from a 15-cm-wide annulus rises to 3 A/cm2 in 10 ns then remains constant causing significant beam pinch. The resulting contours at 30 ns from MAGIC2D and Lsp (and 3D expected) are very similar and show a maximum pinched magnetic field of ~0.018 tesla 1.2 meters from the cathode [4]. SUMMARY: The responses of MAGIC and Lsp on air ionization test problems using simple geometric representations of generic electron beam chamber experiments demonstrate significant agreement of dense plasma models in total. MAGIC also enables the convenient representation of more complex gas mixtures causing dense plasmas. The new MAGIC3D
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version will permit increased geometric detail of dense plasma models, as well as the specification of user-defined gas mixtures. References [1] B. Goplen, et. al., “User-configurable MAGIC for Electromagnetic PIC Calculations,” Computer Physics Communications 87 (1995), (see also www.mrcwdc.com). [2] Lsp is an EM PIC code product of Alliant Techsystems. http://www.mrcwdc.com/LSP/description.html [3] D. V. Rose, et. al., “Computational Modeling of High Pressure Gas Breakdown and Streamer Formation,” 2007 IEEE Pulsed Power Conference Digest of Technical Papers, 2007. [4] A. Woods and L. Ludeking, “MAGIC Electromagnetic FDTD-PIC Code Dense Plasma Model Comparison with Lsp”, summary of paper submitted to Tenth International Vacuum Electronics Conference - IVEC 2009, 28-30 April 2009, Rome, Italy.
01P-41: Modeling of a Gridded Electron Gun for Traveling-Wave Tubes
C. C. Xavier1, C. C. Motta2 1Instituto de Pesquisas Energticas e
Nucleares/CNEN-SP, Sao Paulo, Brazil 2University of Sao Paulo - USP, Sao Paulo, Brazil
EGUN code was used to model a 0,7μPerv electron gun with grid and shadow grid under space-charge limited flow to be used in a traveling-wave tube (TWT). The basic parameters design are to obtain a 2.0 mm beam-waist and a 6.5 compression ratio. Five freedom parameters input were varied: cathode radius disc; electrode focus angle; cathode-to-anode distance; grid-to-cathode distance; and grid voltages. For each set, grid voltages ranged from 0V to 600V with 100V step. As a result, on each simulation current, perveance and laminarity of the electron beam flow was observed. It was also observed a decreasing of gun perveance and current when the grid voltage is on when it compared to the gun project without grid. Current and perveance behavior of the five parameters above are presented. In order to easily establish the beam-waist distance from the anode, a 3-Dimensional viewer of the EGUN output current density data was developed. An experimental setup of the electron gun is in final assembling stage and is also presented.
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01P-42: ELECTRON Family Generators of Atmospheric Plasma with Runaway
Electrons A. N. Maltsev1, I. R. Arslanov2, A. Y. Ivanov2,
D. Y. Kolokolov2, I. N. Lapin2, S. N. Garagaty2, V. V. Chupin2
1Institute of Atmospheric Optics Russian Academy of Sciences, Tomsk, Russian
Federation 2Electrodinamic Systems & Technologies, LLC,
Tomsk, Russian Federation
The "Electrodynamic Systems & Technologies", LLC (Tomsk, Russia, [1]) had developed the product line of new type atmospheric plasma generators named "ELECTRON". This product is intended, first of all, for generation of new type cold and practically homogeneous ADRE-plasma (Atmospheric Discharge with Runaway Electrons) [2]. The uniqueness of ADRE-plasma is associated with big number of fast (runaway) electrons with energy up to tens of kiloelectronvolts (in comparison with all other types of atmospheric plasma had the average electron energy of several electronvolts only). High energy allows runaway electrons to cover distance up to tens of centimeters in air under atmospheric pressure and does possible to use ADRE-plasma for wide range of applications where electrons must have the energy much more than several electronvolts. Typical areas of ADRE application are treatment, sterilization or conversion of gases and liquids; treatment, modification, activation, covering, and sterilization of solid state surface of glass, polymer materials, textile, nonwoven fabrics, etc. There isn't necessary to use any vacuum chambers, or expensive inert gas. The ADRE-plasma is working in free of charge atmospheric air under the normal conditions, as well as in mixture of water aerosol with air, or in dense natural gas, and different other dense gaseous media. The construction of ADRE-plasma generator “ELECTRON” consist of a high voltage pulse generator “PROTEUS” as the basic power supply unit, and atmospheric air electrode unit with ventilation and ozone destruction blocks covered by metal grounded shield with support feet. There are two types of connectors between this units – coaxial high-voltage cable or oil filled coaxial metallic transmission line. Three models of high voltage pulse generators of “PROTEUS” line characterized by different durations of high voltage leading front from 150 ns down to 1 ns can be used as a power supply unit. So there are three types of plasma generators "ELECTRON-I", "ELECTRON-II", and "ELECTRON-III" based on respective high voltage generators of "PROTEUS" line. One of several types of standard electrode unit can be used for each plasma generator of "ELECTRON" line with linear
dimensions up to 200 cm. The atmospheric plasma overall cross section square can reach up to 1500 cm2 for one electrode unit, and the inter-electrode gap can be regulated in the region of 2-6 cm. The output voltage pulse amplitude is about 20-70 kV for different gaps. Output voltage pulse power can reach up to 50 MW. Pulse half-height duration is 4 to 400 ns for different models. Pulse repetition frequency can be regulated up to 2 kHz. There are three types of control - manual (using control panel with digital indicator), external analog triggering, and computer based. References. 1.http://www.edynamicst.com/en/production_en/plasma_generators_Electron_en 2. A. N. Maltsev, “Fast electron, ion, atom, UV and X-Ray radiation beams, as well as ozon and/or other chemically active molecules generation in dense gases”, Patent # 2274923 of Russian Federation, with priority since September 01, 2003.
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01P-43: Twin Electron Beam Diode Design
A. W. P. Jones Hydrodynamics, Atomic Weapons Establishment,
Reading, United Kingdom
The feasibility of creating additional radiographic sources using some of the loss current in AWE’s next generation flash x-ray machines to is being investigated. Particle in cell simulations of the acceleration region of two paraxial diodes are modelled in the code LSP [1]. These simulations represent trial of this system on the pulsed power accelerator EROS in what is expected to be an overly challenging close, 80mm axis to axis separation, of two beams. The simulations are used to predict that the electron beams could transit the 50mm gap with negligible deviation. The design of the experiments to test this system are then presented. Comparison is made to previous work with the beams at significantly greater separation [2]. [1] D.R. Welch, D.V. Rose, M.E. Cuneo, R.B. Campbell, T.A. Melhorn, Phys. Plasmas 13, 063105 2006 [2] G Cooper, J McLean, R Davitt, “Recent X-Ray Diode and Magnetically Insulated Transmission Line Experiments Performed on the 5.5MV Superswarf Machines at AWE Aldermaston, Proceedings of the IEEE Pulsed Power Conference 2001
01P-44: Misalignment Effects on Beam Dynamics in AIRIX
S. J. Pichon, M. Caron, L. Hourdin CEA DAM Ile-de-France, Arpajon, France
The AIRIX facility is a high current induction linear accelerator designed for radiography applications. Obtaining an appropriate electron beam requires a very accurate knowledge of the machine. Some discrepancies observed between beam transport theoretical results and measurements may be explained by a misalignment of the diode extraction magnetic system which would give to the beam a dissymmetric behaviour. System misalignment is likely to come from a coil shift or tilt with respect to the accelerator axis. To evaluate the produced beam perturbation, diode magnetic field measurements have been undertaken with a 3D Hall effect probe and an estimation of the system misalignment has been retrieved from the detected signatures using a 3D electromagnetic code. Then, further beam dynamics simulations can quantify the impact of the misalignment on the beam performances.
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01P-45: Explosive Velvet Cathode Emission on a 4 MV, 2 kA, 60 ns Pulsed
Power Diode M. Toury, M. Caron, R. Rosol, B. Etchessahar
CEA Polygone d'Expérimentation de Moronvilliers, Pontfaverger-Moronvilliers, France
Pulsed Powed diode play a key role on the final performances of a Linear Induction Accelerator (LIA). Usually, for a complete beam characterisation at the diode output the following set of data is required: the primary beam current intensity (I), the primary beam energy (E), the mean angular beam dispersion (X’,Y’), the RMS beam size (X,Y) as well as the beam emittance. The first two parameters are given in a routine way by the regular electrical captors present into the beam lines. For the last three ones, a classical beam diagnostic based on the detection of the electron induced Cerenkov radiation is a kind of standard. The drawback of this approach is that beam has to be intercepted to be characterized. We propose in this paper a first step toward an in line method based on explosive cathode plasma imaging and modelisation.
01P-46: Determination of Emission Behaviour of Carbon Fibre Cathodes
W. An, G. Mueller, A. Weisenburger Institut für Hochleistungsimpuls- und
Mikrowellentechnik, Forschungszentrum Karlsruhe Institute fro Pulsed Power and
Microwave Technique, Eggenstein-Leopoldshafen, Germany
Multipoint emission cathodes are used in our institute to modify materials by using the generated large intense pulsed electron beams (GESA). To investigate the emission behaviour of carbon fibre cathodes, like they are used in the GESA facilities a single fibre bundle experiment was designed. In a vacuum chamber a single carbon fibre is connected via a resistor with a spark attached to a capacitor. Using serial resistors the current through the fibre tip could be varied. The potential of the carbon fibre was controlled by active voltage divider. The electrical wiring of the carbon fibre correlates the one of the GESA IV. The anode of the experimental set-up takes over the function of the grid of the real device. The development of the plasma is measured using high speed photography along the fibre axis. The individual carbon fibres have a diameter of 7µm with a length of about 20mm. One fibre bundle like used in a GESA cathode consists of several hundred single fibres. In the first phase of discharging using two single fibres the lightning of the individual fibre pike is visible. Due to increasing current the the fibre starts to glow around these points. Simultaneously at the bottom where the cutted fibres protrude an intensive lightning point develops. Estimations of the temperature at the tip indicate that they are sufficient high to heat the tip above sublimation temperature. Therefore, a point emission at the fibre tip during the entire time of the discharge is highly improbable. Instead, the fibre emits along its entire length.
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01P-47: Multicapillary and Carbon Fiber Cathodes for High-Current Electron
Beam Generation J. Z. Gleizer, V. Vekselman, Y. Hadas,
V. T. Gurovich, Y. E. Krasik Physics, Technion Israel Institute of Technology,
Haifa, Israel
Results of high-current sub-microsecond duration electron beam generation in a ~200kV diode with multicapillary dielectric cathode (MCDC) assisted by a ferroelectric plasma source (FPS) and carbon fiber cathodes with current densities ~40A/cm^2 are presented. It was shown that the operation of the MCDC is determined by the parameters of the plasma flow generated by the FPS. It was found that the high resistivity of the plasma produced inside capillaries allows effective de-coupling of individual capillary plasma discharges that results in uniform electron beam generation. It was shown that in the diode with carbon fiber cathode during the accelerating pulse, generation of the plasma occurs in a form of several mm size plasma spots randomly distributed on the cathode surface. In the vicinity of the cathode surface average plasma density and temperature were found to be ~3×10^14cm^−3 and ~5eV, respectively, for electron current density ~22A/cm^2 and the plasma expansion velocity towards the anode was found to be ~1.5×10^6cm/s during first 150ns of the accelerating pulse.
01P-48: Negative-Polarity Rod-Pinch Diode Experiments on RITS-6
J. J. Leckbee1, B. V. Oliver1, M. D. Johnston1, K. Hahn1, S. Portillo1, B. Bui2
1Sandia National Laboratories, Albuquerque, NM, United States
2Ktech Corporation, Albuquerque, NM, United States
Pulsed power driven flash radiography is used for the interrogation of dense materials during dynamic experiments. High quality x-ray imaging requires high x-ray dose from a small source size. The Negative-Polarity Rod-Pinch (NPRP) diode is being developed and tested on the RITS-6 accelerator to expand radiographic capabilities to meet future requirements. Results of these experiments will be discussed. The NPRP diode consists of a long rod shaped anode which extends through a hole in the center of a flat plate cathode. Electrons are emitted from the edge of a hole in the cathode plate and attach to the tip of the anode rod. In the negative polarity configuration, x-rays are extracted through the rod and out the end of the accelerator. The Rod-Pinch diode has been studied on several pulsed power drivers in both positive and negative polarities and voltages in the range 1–6 MV. Experiments on the RITS-6 accelerator were conducted in what is known as the low impedance configuration where the accelerator produces a 7.5-MV pulse on a 40-ohm magnetically insulated transmission line (MITL). Experimental results and observed trends will be discussed. ____________________________ *Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.
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01P-49: Radiographic Diode Optimization in the Presence of Sheath Current in a
MITL on RITS-6 K. Hahn1, B. V. Oliver1, D. V. Rose2, N. Bruner2,
D. R. Welch2, V. Bailey3, J. J. Leckbee1, E. Schamiloglu4
1Sandia National Labs, Albuquerque, NM, United States
2Voss Scientific, Albuquerque, NM, United States 3L-3 Communications, San Leandro, CA, United
States 4University of New Mexico, Dept. of Electrical and Computer Engineering, Albuquerque, NM, United
States
Several electron-beam-driven diodes are currently being investigated to develop intense x-ray sources for high-brightness flash radiography on the RITS-6 accelerator (7-12 MV, 180 kA, 70 ns FWHM) at Sandia National Laboratories. RITS-6 utilizes a magnetically insulated transmission line (MITL) to couple the electromagnetic power pulse to the diode. In a MITL, the total current is divided between bound current electrons that flow in the cathode conductor and free electrons referred to as sheath current that flow between the cathode and anode. The large scope of diode operating conditions can be classified relative to the impedance of the MITL as either high-impedance (i.e. paraxial diode) or low-impedance (i.e. pinched-beam diodes). For each diode, the presence of sheath flow can lead to several deleterious effects on the diode operation which include excitation of cavity modes in various locations in the accelerator, producing unwanted background x-ray sources, and requiring a large, cumbersome geometry. Whether operating at high or low-impedance, extensive control of the sheath current flow is required. Particle-in-cell codes such as LSP are often used to design the interface between the MITL and diode. Key results from simulations are presented and compared to experimental measurements for various configurations presently fielded on RITS-6. Proposed improvements to existing designs largely based on simulations are also presented. * Work supported by Department of Energy’s National Nuclear Security Administration under Contract DE-AC04-94-AL85000.
01P-50: Measurements of Energy Spectra and Spatial Profile of Large-Area Diode
RITS-6 Electron Beam T. J. Webb1, B. V. Oliver1, D. R. Welch2, J. Zier3,
Y. Y. Lau3, R. Gilgenbach3 1Sandia National Laboratories, Albuquerque, NM,
United States 2Voss Scientific, Albuquerque, NM, United States
3University of Michigan, Ann Arbor, Michigan, United States
The RITS-6 induction voltage adder (IVA) electron accelerator has an output voltage of 7-12 MV and beam currents from about 10 kA to 170 kA depending on the diode employed and the two options for the vacuum transmission line impedance of the magnetically insulated transmission line (MITL). The determination of the diode voltage has traditionally be done by a combination parapotential flow theory in the MITL and translating the voltage pulse to the diode and/or solving radiographers equations for the x-ray dose rate. However the time-integrated voltage can also be inferred from the electron beam energy spectrum unfolded from measurements of the absorbed dose as a function of depth in the anode material. Depth dose measurements using radiochromic film sandwiched in an aluminum anode were performed with the high impedance MITL. Results are presented for the unfolded electron spectrum using a modified least-squares optimization method with Monte Carlo radiation transport code generated mono-energetic depth-dose profiles. Variations in the beam spatial profile are observed. Time-resolved measurements of the beam current density were performed by gated CCD cameras observing the beam-generated Cerenkov light pattern inside range-thin fused silica. These measurements were made at similar beam current but lower voltage than the depth-dose shots. Various cathode surface treatments were used to see if beam profile depended strongly on the electron source. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energys National Nuclear Security Administration under contract DE-AC04-94AL85000.
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01P-51: Development of a Large Area, High Current, Repetitively Pulsed Diode
for KrF Lasers* M. C. Myers1, J. D. Sethian1, F. Hegeler2,
M. Friedman2, M. F. Wolford1, P. M. Burns3, R. L. Jaynes4, J. L. Giuliani1
1Plasma Physics Division, Naval Research Laboratory, Washington, DC, United States
2Commonweatlth Technologies, Inc., Alexandria, VA, United States
3Research Support Instruments, Lanham, MD, United States
4Science Applications International Corp., McLean, VA, United States
The kilo-Joule class, repetitively pulsed, krypton-fluoride (KrF) lasers being developed for use in inertial fusion energy research require large area vacuum diodes that are durable and efficient. Emitters of 1000’s of cm2 must reliably produce 100’s of kA at voltages up to 1 MV in flat-topped, sub-microsecond pulses, at pulse repetition frequencies (PRF) up to 10 Hz for 10E5 – 10E8 continuous shots. The electron beams are produced in vacuum diodes that are immersed in an external magnetic field. Each beam must be efficiently delivered to the high pressure laser gas through a thin anode foil that is supported by a ribbed anode structure. Diode development at the Naval Research Laboratory is being conducted on the Electra KrF Laser’s main amplifier which generates nominal 500 kV, 110 kA, 100 ns flat-top pulses at up to 5 Hz PRF. Durability has been demonstrated on continuous 2.5 Hz runs of greater than 60,000 shots using a 3,000 cm2 carbon fiber-based emitter, with present cathode life exceeding 0.5 million shots. Greater efficiency has been achieved on continuous 2.5 Hz runs of greater than 10,000 shots with a carbon fiber-based emitter that is patterned into beam strips by utilizing soft iron to shape the local magnetic field. Anode foil lifetime issues were addressed by using the laser gas to convectively cool the foil, by eliminating voltage reflections that cause emission from the anode, and by alleviating the causes of slow fall time of the driving pulse. Details of the diode development process and time resolved electrical and optical measurements of electron emission will be presented. Solutions for anode foil cooling and voltage reversal mitigation will be discussed.
01P-52: Modeling Multipactor in RF Devices
P. H. Stoltz, C. Nieter, C. Roark Tech-X Corporation, Boulder, CO, United States
Multipacting limits the performance of many high power rf devices. We show simulation results for 3D integrated modeling of multipacting, including accurate geometries, rf fields, and secondary emission models. In particular, we show application of this modeling to a 56 MHz superconducting quarter-wave structure being designed at Brookhaven National Laboratory. We show in that structure that multipacting occurs both radially between the inner and outer conductors and diagonally between the inner conductor and the corner of the outer conductor and axial end plate. We discuss how this multipacting scales with power and with geometry modifications, including modifications to add ripples to the outer conducting surface.
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01P-53: Terahertz Radiation Generation via Optical Rectification of X-Mode Laser in a Rippled Density Magnetized Plasma
V. K. Tripathi, L. Bhasin Physics Department, Indian Institute of
Technology Delhi, New Delhi, India
A scheme of resonant terahertz radiation generation by the optical rectification of a picosecond laser pulse or nonlinear mixing of two cw lasers in rippled density magnetized plasma is proposed. The X-mode laser pulse propagating perpendicular to dc magnetic field exerts a longitudinal ponderomotive force on electrons driving a current with finite transverse component and producing THz radiation at frequency equal to the inverse pulse duration. The terahertz power scales as the square of density ripple amplitude and rises quite strongly with magnetic field strength. In case of two co-propagating lasers, one produces THz radiation at the difference frequency. At laser intensity of 10 ^ 16 W/cm ^ 2 the power conversion efficiency into the THz wave at typical parameters turns out to be about 1 %.
01P-54: Electron Beam Source Based on the Plasma Sheets Having Micron-Scale
Width D. Yarmolich, V. V. Vekselman, V. T. Gurovich,
J. Felsteiner, J. Z. Gleizer, Y. E. Krasik Physics, Technion, Haifa, Israel
200 keV, 300 ns) generation∼High-current electron beam (1.5 kA, 30 A/cm2, in a diode with a micron-scale width multi-slot cathode is reported. The cathode operation is based on formation of the plasma thick sheets inside the dielectric slots. The plasma, which density and temperature ≤1015cm3 and 7eV respectively, had 25m width and area of few cm2. The dependence of the plasma parameters inside the slots upon the slot’s width as well as the control of the extracted electron beam parameters by varying the slot’s width and the distance between slots have been studied. Presented model allows one to estimate dependence of plasma parameters on the current, neutral density, and slot width for extraction electron beam with required parameters.
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02P: High Energy Density Plasmas and Pulsed Power Switches and Components
East State
Wednesday, July 1 13:30-14:45
02P-1: Prefire Probability of the Switch Type Fast LTD
A. A. Kim, S. V. Frolov, V. M. Alexeenko, V. A. Sinebryukhov
Institute of High Current Electronics, Tomsk, Russian Federation
The LTD technology is promising for numerous applications requiring high-power, high-current power pulses with the rise time of ~50-100 ns. The architecture of the LTD cavities is rather simple including three type of parts only that are storage capacitors, gas spark switches and ferromagnetic cores. The reliability of these parts greatly determine the performance of the whole LTD-based pulsed power system. The most powerful LTD stages with two-polarity charging and oil insulation of the cavity utilize the switches type Fast LTD. These are multi-gap spark switches operating in dry air at a pressure of ~4 ata, where the charge voltage is distributed between the gaps by using the corona discharge from negative needles. This is a new technology, and many features of the corona discharge in such conditions are not clear at the moment. In the report we present the most recent data related to prefire probability of the switches type Fast LTD.
216
02P-2: Synchronous Triggering of Multiple, Electrically-Isolated Vacuum Switches Using a Coaxial Transformer
V. Gorodetsky High Power Solution Division, Science
Applications International, Manassas, VA, United States
A coaxial transformer-based trigger circuit has been developed to provide high voltage isolation between multiple vacuum switch devices. The circuit, which can be operated from a 5 kV MS32 trigger unit, provides a sufficient drive to the UV trigger electrode in each vacuum switch. The coaxial transformer provides isolation between the trigger electronics and the high voltages associated with the vacuum switch plasma. The transformer also provides isolation between each of the switches. The use of a coaxial transformer in this application makes the overall circuit inductance less critical compared to direct triggering of the switches. The coaxial transformer-based triggering approach enables reliable switching of the number of vacuum switches simultaneously.
02P-3: Experiment and Circuit Model of Laser-Triggered Flashover Switch R. Z. Pan1,2, J. Wang1, W. M. Ouyang1,2,
G. S. Sun1, P. Yan1 1Institute of Electrical Engineering, Chinese
Academy of Sciences, BeiJing, China 2Graduate University, Chinese Academy of
Sciences, BeiJing, China
Based on the platform of laser-triggered surface flashover in pulsed voltage, experiment of laser-triggered surface flashover is carried out using the flat electrodes and columned insulators of nylon. A single/double harmonic, with wavelength λof 1064/532 nm, Q-switched Nd:YAG laser is applied to trigger the insulators surface flashover. The synchronization of laser pulse and voltage pulse is achieved by the control of digital delay/pulse generator. The circuit model of laser-trigger flashover switch is set up by circuit method in the study. The parameters of the circuit model are calculated through the waveforms of the experiment. The waveforms of voltage and current are obtain through circuit simulation. In addition, the results of experiment show that flashover delay time and jitter time decrease with increase of pulsed voltage and laser energy density. The simulation waveforms of the switch model are consistent with the waveforms of the experiment.
217
02P-4: Experiment of Laser-Triggered Flashover in Pulsed Voltage
R. Z. Pan1, 2, J. Wang1, W. M. Ouyang1,2, G. S. Sun1, P. Yan1
1Institute of Electrical Engineering, Chinese Academy of Sciences, BeiJing, China
2Graduate University, Chinese Academy of Sciences, BeiJing, China
With the aim of studying the characteristics of laser-triggered surface flashover in pulsed voltage, synchronization problem of laser pulse and voltage pulse is solved through a high precision trigger system. The experimental platform of laser-triggered surface flashover in pulsed voltage is built up in the laboratory. A single/double harmonic, with wavelength λof 1064/532 nm, Q-switched Nd:YAG laser is applied to trigger the surface flashover. Based on the platform, experiment of laser-triggered surface flashover is carried out using the flat electrodes and columned insulators. The material of electrode is stainless steel and the electrode diameter is 100mm. Three kinds of insulations are tested in the experiment. The materials of insulations are nylon, polycarbonate and Al2O3, respectively. The diameter of insulation is 20mm, and insulations thickness are 6mm, 8mm and 10mm. Laser pulses wavelength are 532nm and 1064nm, and laser is focused with 2mm30mm rectangle. The results of experiment show that flashover delay time and jitter time decrease with increase of pulsed voltage and laser energy density. In addition, the comparison of the three kinds of insulation is obtained through the result.
02P-5: Radial Design of Closing Multigap Switch
V. Kladukhin, S. Khramtsov, S. Kladukhin, V. Yalov, P. Zagulov
Institute of Electrophysics of Russian Academy of Sciences, Ekaterinburg, Russian Federation
An approach of designing of axial-radial type closing multigap switch is described. Switch commutation process is based on self-propagation of overvoltage across gaps. Commutation process initiating is implemented by applying an overvoltage to the gap which is adjacent to the inner electrode. Such gap switches could be used in highcurrent and highvoltage generators of nanoseconds pulses as commutators of double forming lines. Process dynamic modeling and design features are described. Experimental testing results of switch are also presented in this paper.
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02P-6: Breakdown Strength Criteria of a Spark Gap Switch in High Pressure SF6
Gas for Pulsed Power S. H. Nam1, H. Rahaman1, H. Heo1, S. S. Park1,
J. W. Shin2, J. H. So2, W. Jang2 1Pohang Accelerator Laboratory, Pohang, South
Korea 2ADD, Daejeon, South Korea
A spark gap is a significant component in pulsed power applications. However, it is indeed difficult to design the spark gap switch unless the electrical breakdown strength of SF6 gas is correctly predicted. We have developed an empirical formula, which takes into account the field enhancement factor (FEF) of the spark gap geometry, to determine the breakdown strength of SF6 gas in a high pressure range with a great precision. The result showed a very good approximation with several published experimental data. In support of the above empirical approach, a spark gap switch is designed and constructed at Pohang Accelerator Laboratory (PAL). This spark gap switch is coupled with a 33 stage PFN Marx system to generate fast rise time high power impulses at a matched load. The measurement data are noted for self–breakdown electric field strength of the spark gap in different SF6 pressures. The computed breakdown field strength as a function of the operating pressure is in good agreement with the experimental data. Successful operation of the spark gap is proven very well, for the range of gas pressures considered, up to the breakdown voltage of about 1.2 MV.
02P-7: Study of Arc Velocity in an Arc-Rotating Gap Based on B-dot Probes
R. Guo, J. He, C. Zhao, L. Chen, Y. Pan Dept. High Voltage Engineering, College of Electric and Electronic Engineering, Hust,
Wuhan, China
An arc-rotating gap and the arc velocity were investigated. The electrodes were coaxial and the arc was driven by the axial magnetic field generated by the coils which located in the top and bottom of the switch. The coils were connected to the inner electrode and created a magnetic mirror field. Magnetic flux density at the gap is proportional to the current. The arc rotation velocity was measured by B-dot probes. In order to obtain the arc velocity variation of each circle, six B-dot probes were installed just below the gap. The time when the arc passsing each probe can received from the probe signals. So the average velocity between two probes was obtained. The arc current was provided by a time-sequence power supply which could generate an approximate trapezoidal waveform. The current was 18-72 kiloampers with pulse width of several microseconds. The correlation between arc velocity and current was studied based on the experimental data. The results showed that the arc rotated in high speed so the electrode erosion was limited. The arc velocity reached a remarkable peak value in first two or three circles and then oscillated at a lower value in the plateau of arc current waveform. The surface drag force is varied during rotation and it was an important factor to balance the magnetic force. The arc velocity was approximated proportional to the current 1.1 times power in this situation by fitting the experimental data. The switch worked in atmospheric air.
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02P-8: Multigap Pseudospark Switch for FAIR
K. Frank1, I. J. Petzenhauser2, B. J. Lee3, U. Blell2
1Center for Pulsed Power and Power Electronics, Texas Tech University, Lubbock, TX, United
States 2FAIR Synchrotrons, GSI Helmholtzzentrum fuer
Schwerionenforschung GmbH, Darmstadt, Germany
3Institute of Applied Physics, Goethe University, Frankfurt, Germany
At the GSI Helmholtzzentrum fuer Schwerionenforschung GmbH a new accelerator complex, called Facility for Antiproton and Ion Research (FAIR), is under construction. Its main components are the SIS100 and SIS300 heavy ion synchrotrons. To operate their injection/extraction kicker magnet systems, modulators with pulse-forming networks (PFNs) are necessary. The PFNs will be charged to a high voltage up to 70 kV and discharged via a high-voltage switch. The switch has to handle currents up to 6 kA, pulse durations up to 7 microseconds with an overall lifetime exceeding 10^8 shots. The repetition rate is about 4 Hz and a current rise rate of at least 3.5*10^10 A/s is required. The only commercially available switch in this parameter range is actually a multi-gap thyratron. As an alternative, a three-gap pseudospark switch is under development at GSI since three years. It combines the major advantages of the thyratron with its low stand-by power as a cold-cathode device. Like for the thyratron, the maximum hold-off voltage of a single gap pseudospark switch is limited to about 35 kV. For a hold-off voltage of 70 kV, a three-gap system was designed. A first sealed-off prototype switch of this design is under test at the moment. It already could be a voltage hold-off capability of more than 80 kV demonstrated. The circuit of capacitive and resistive voltage dividers was optimized and the results for different setups are reported. As trigger an improved high-dielectric trigger module was developed. The results of delay and jitter are presented. With such an high-dielectric trigger unit a crucial issue for minimum delay breakdown remains the plasma coupling between the different gaps by optimized drift-spaces. Therefore the drift-space between the gaps was further improved with regard to low-inductance and fast plasma coupling, respectively. Finally first results of experiments with saturable inductors in the anode circuit show the benefit of those devices.
02P-9: Measurement of the Effective Length of Laser-Plasma Channels in a Laser Triggered Gas Switch by Guided
Microwave Backscattering M. Gilmore1, B. S. Stoltzfus2, M. E. Savage2,
A. G. Lynn1 1University of New Mexico, Albuquerque, NM,
United States 2Sandia National Laboratories, Albuquerque, NM,
United States Laser triggered gas switches are critical components in many pulsed power driven systems, such as ZR at Sandia National Laboratories. Timing jitter is of concern is such systems, where power flow from multiple modules must be switched to a load simultaneously. Laser triggered gas switches utilize a laser-produced plasma channel (LPPC) to initiate breakdown between electrodes biased to ~ 80% of breakdown voltage. The effective length of the LPPC is an important parameter affecting the breakdown timing. Backscattering of microwaves inside a waveguide by an LPPC, introduced by focusing the trigger laser through holes in the broad wall, has been used to characterize effective length of the channel. Simulations indicate that the backscattering is sensitive to the LPPC conductor length both inside and outside the waveguide. A quarter wavelength stub has therefore been introduced outside of the waveguide, to short circuit the LPPC conductor to the waveguide wall, while still allowing laser access. Theoretical, computational, and initial plasma channel experimental results, as well as comparisons with other diagnostics, are presented. * Work supported by Sandia National Laboratories
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02P-10: Development of High-Power Photoconductive Semiconductor
Switches W. Xie1, H. Li1, H. Liu1, J. Liu1, J. Yuan2,
X. Wang2, W. Jiang2 1Institute of Fluid Physics, CAEP, Sichuan, China 2Department of Electrical Engineering, Tsinghua
University, Beijing, China
Photoconductive semiconductor switches (PCSSs) have been considered as a promising high-power switching device, and used in high-power ultra wideband microwave source, compact pulsed power generator, and so on. In the past 30 years, PCSSs have been fabricated from Si, GaAs, InP, diamond, ZnSe, SiC, and GaN. Semi-insulating GaAs photoconductive semiconductor switches have been investigated. Photoconductivity tests were performed with different laser wavelength, optical energy and bias voltage. Peculiar photoconductivity, which means the “lock-on” current increased instead of staying on a constant value after the trigger laser pulse had ended, was found. In order to understand the influence of laser beam profile on photoconductivity of the PCSS, several types of laser beam profile have been used, such as illumination throughout the surface of the PCSS, 1-mm-wide strip illumination spanning the electrode gap, 1-mm-wide strip illumination parallel to the electrode, and laser spot. 1-mm-wide strip illumination parallel to the electrode was respectively located at the center of the gap, near the cathode and near the anode. An overview of the GaAs PCSSs characteristics and experimental results will be presented. As a switch material, SiC has several advantages over the other known materials. We are in the process of developing high-power SiC PCSSs, and initial experimental results will also be presented. *Work supported by the National Natural Science Foundation of China under Grant 50837004
02P-11: Performance Improvements of the 6.1-MV Laser-Triggered Gas-Switch
on the Refurbished Z K. R. LeChien1, W. A. Stygar1, M. E. Savage1,
D. E. Bliss1, P. E. Wakeland2 1Sandia National Laboratories, Albuquerque, NM,
USA 2Ktech Corp., Albuquerque, NM, USA
Qualifying the initial design of the refurbished Z laser-triggered gas-switch (LTGS) was conducted on a single-switch test module at a peak voltage of 5.4-MV and peak current of 700-kA. At this level, and on the single-switch test bed, the switch had a jitter of ~5 ns, a prefire and flashover rate of less than 0.1%, and a lifetime in excess of 150 shots. When the same design was implemented on the 36-module Z-machine, the prefire probability increased a factor of 30, the flashover probability increased by a factor of 70. All insulator flashovers occurred at the bottom of the switch, and were attributed to collection of contamination that was influenced by gravity. The jitter increased by a factor of 3, largely because of the necessity to operate switches at high pressure to avoid flashover and because of the inability to verify laser alignment just before a shot. Under these conditions the replacement lifetime was less than 10 shots. In addition, the maximum operating point increased from 5.4-MV at 700-kA to a peak voltage of 6.1-MV and a peak current of 790-kA to drive loads of interest. Since the initial deployment of the refurbished Z LTGS in October 2007 there have been three major design iterations to improve the performance to an acceptable level. The size of the switch and the lasers utilized were constrained for these design iterations because changes to these components were cost prohibitive. The most recent design iteration has reduced the random prefire rate to 0.7%, reduced the flashover rate to ~0.4%, reduced single switch jitter to ~6-ns, and increased the average switch life to greater than 50 shots. These major performance improvements were attributed to i) insulator housing redesign, ii) utilization of low-erosion metal for electrodes, iii) addition of a fast and turbulent SF6 gas purge, and iv) improvements to laser alignment verification. The switch is ~80-cm in length, 40-cm in diameter, and is immersed in transformer oil. The switch is pulse-charged from a 780-kJ, 6-MV Marx generator in 1.4-µs. Closure of the switch allows energy stored in a 24-nF intermediate-store water capacitor to flow into subsequent pulse-forming stage. The entire system (36-modules) generates a ~70-TW at the present system operating level, but after near term improvements are complete, this level will increase to ~100-TW. The reliability, predictability, and reproducibility of gas switch performance, and therefore machine
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performance since machine jitter is dominated by gas switches, is discussed. New designs aimed at reducing the prefire rate by a factor of ~2 and reduce switch jitter by at least a factor of 2 are discussed.
02P-12: Investigation of UV LEDs for Compact Back-Lighted Thyratron
Triggering C. Jiang, E. Sozer, H. Chen, W. Johnson,
M. A. Gundersen EE-Electrophysics, University of Southern California, Los Angeles, CA, United States
The back-lighted thyratron (BLT), an optically-triggered pseudospark switch, employs high energy (e.g. UV) photons to produce photoelectrons and initiate the breakdown: a low-pressure high-power glow discharge. Characteristic of these switches are high-voltage hold-off (>30 kV), high peak current capability, excellent current rise rate (up to 10^12 A/s) and a simple device geometry [1]. It is of interest to develop ultra-compact BLTs [2] with reliable and practical optical triggering systems for applications in compact pulsed power. Recent remarkable advances in ultraviolet (UV) light emitting diodes (LEDs) [3] have potentially enabled new optical trigger schemes for compact BLTs: replace expensive trigger light sources such as gas lasers, upconverted-YAG lasers or UV flash lamps, and thereby substantially simplify the light-triggered BLT systems, significantly reducing the total switch cost and the BLT system volume. In this work, potential utilization of UV LEDs for BLT triggering is discussed. The photoelectron yields are measured for metal photocathodes illuminated by a 277 nm UV LED which is driven by current pulses of varying durations at a pressure range typically for BLT operation. The number of photoelectrons needed to generate an avalanche in a switch and initiate breakdown is extrapolated from measurements of BLT-based, electron-beam current. *This work is supported by the Air Force Office of Scientific Research. [1 ] C.G. Braun, W. Hartmann, V. Dominic, G. Kirkman, M. Gundersen and G. McDuff, “Fiber optic triggered high-power low-pressure glow discharge switches,” IEEE Trans. Electron Devices 35 (4), 559 (1988). [2 ] C. Jiang, A. Kuthi, and M. A. Gundersen, “Toward ultracompact pseudospark switches,” Appl. Phys. Lett. 86, 024105 (2005). [3 ] A. Lunev, J. Zhang, Y. Bilenko, X. Hu, J. Deng, T. Katona, M. Shur, R. Gaska, and M. Asif Khan, “A 110 mW AlGaN-Based UV Lamp emitting at 278 nm,” Device Research Conference Digest, DRC'05, 21 (2005).
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02P-13: High Action Switching with the Extreme Break over Diode (XBOD®)
A. Griffin, D. Giorgi, G. Celestin, T. Navapanich OptiSwitch Technology Corporation, San Diego,
CA, United States
Many pulsed power systems require highly reliable, fast turn-on and high action (I2t) switches. High reliability can be achieved by solid-state switches and high action switching has typically been performed by large area, low voltage (4-6 kV) and low dI/dt silicon thyristors. High dI/dt thyristors due to their highly integrated gates or small areas are limited in action and thus many are required in parallel. The series and parallel operation of individual switches, in individual packages, where each switch requires a separate trigger signal results in a larger than necessary switch package. The Extreme Break Over Diode (XBOD®), developed by OptiSwitch Technology Corporation (OTC), is an large area (88 mm diameter), 4 kV “gateless” silicon thyristor which is turned on by a dV/dt pulse to the anode. The elimination of a gate enables multiple large area XBODs® to be integrated into a single package and triggered by a single pulse. These features result in a compact, high voltage (12-20 kV), high current (100-200 kA) and high action switch for many pulsed power applications. In this paper we will report on the design of the XBOD® and the switching of a 4-stack and 5-stack XBOD® with measured action of greater than 5 MA2-sec.
02P-14: Pulse Triggered Spark Gap Design Aided by Charge Simulation Method with Consideration of Space
Charge Effects L. S. N. Wang
Electromagnetic Survivability Division, Survivability & Vulnerability Assessment
Division/WSMR, White Sands Missile Range, United States
A computer aided designs code to optimize the switch performance of spark gaps are synthesized through various design parameters, specifically, electrode geometric configurations (inter-electrode and gap spacing), gas pressure, mixtures and polarity of working and triggering pulse shape, and over-voltages, etc. Since the ionization initiated breakdown processes are very sensitive to distorted fields during the pulsing transient stage, a static Charge Simulation Method (CMS) [1] to evaluate the triggering impacts by field distortions is implemented. In CSM code, contour points at equal-potentials of main electrodes composed of plane or axially symmetric (straight line, circle, parabola, hyperbola, etc.) shapes and the trigger electrode of specific geometry and relative position are programmed along with position specifications of points, lines or rings for virtual charges confined inside each equal-potentials to formulate a system of charge-position potential equations. The values of virtual charges are solved by conventional matrix inversion, or accelerated by such as Gauss-Seidel or over-relaxation iterative algorithms, but usually introduce with numerical oscillations along contour points. Least Square and augmented numerical techniques are adopted to minimize associated oscillatory potential contours. With CSM calculated distributed fields E within inter-electrodes, or reduced electric fields E/N with which reduced ionization coefficients, alpha - elta, are correlated, breakdown criteria, Townsend's for static threshold or Raether’s criterion for the space charges dominating diffusion avalanche, are evaluated for one particular field line, along which it reaches its maximum value. Furthermore in order to evaluated the space charge impact, equivalent virtual charges are devised for spheroid shapes as space charge expanding from ionization positions along axial avalanche positions between anode / cathode and trigger electrode. These dynamic space-charge equivalent virtual charges in positions of ring shells are additive to the original static virtual charges are solved and then tentative to be incorporated in previously developed transient SPARKGAP code, both in space and time, at each time step of outer iterations [2]. Special attention paid to three-electrode designs, particularly, with an sharp edged trigger electrode and its streamer competing processes within
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separate sub-gaps, along with fast rising trigger pulse for over-voltages to induce fast gap voltage collapsing, thus, to generate fast rising and higher peak current through the gap. Comparative parametric simulations are provided for possible enhancement of desired gap switch performance.
02P-15: Arc Dynamics in High Current Rail Spark Gaps
A. V. Kharlov Pulsed Power, Institute of High Current Electronics, Tomsk, Russian Federation
Large capacitive energy storage systems are being implemented for powerful laser systems, electromagnetic launchers, and other pulsed power systems. Such MJ-class modularized capacitor banks individually require precise, reliable, cost-effective, and robust closing switches for synchronous operation. The closing switch, under intense mechanical and thermal shocks imposed by the high peak current, must tolerate high charge transfer, and provide long service life. The most popular closing switches up to date are spark gaps due to relatively simple design, robustness, easily field maintenance and repair. Main drawback of spark gaps is limited lifetime, which is related directly or indirectly to erosion of the electrodes. Various types of switches have been introduced, which utilize principle of arc motion in a magnetic field, thus effectively decreasing the current density on the switch electrodes. Three-electrode gas switches with electrodynamical acceleration of a spark channel have been developed in the Institute of High Current Electronics, Tomsk [1]. In such switches at a given current amplitude the diameter of the extended electrodes allows to control the spark velocity and hence the erosion of the electrodes providing the required lifetime. This report deals with numerical calculations of arc motion and electrodes erosion in rail spark gap. Results of numerical calculations are compared with experimental results in the report. Conditions for reduced electrodes erosion are defined [1] B. M. Kovalchuk, A. A. Kim, A. V. Kharlov et al., "Three-electrode gas switches with electrodynamical acceleration of a discharge channel", Rev. Sci. Instrum., 79, 053504(2008).
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02P-16: Formation of Multi Channels in Multi Gap Gas Switch for Linear
Transformer Driver D. X. Liu
Electrical Engineering/High Voltage, Xi'an Jiaotong University, School of Electrical
Engineering, High Voltage Division, Xi'an, China
Multi channeling discharge can dramatically reduce the switch jitter, inductance and the erosion of the electrodes. To investigate the formation of multi channels in multi gap gas switch for linear transformer driver (LTD), this paper focus on a new method with small balls and grooves for anchoring electrodes on the inside wall of the insulation cylinder of the switch. Symmetrical distribution of discharging channels has been obtained during the closure of the multi channel multi gap gas switch (MMGS). The experimental result indicates that the anchoring method can provide uniform electric field distribution between electrodes, and it is effective to improve the formation of the multi channels in the multi gap gas switch.
02P-17: Development of a Sub-Nanosecond Jitter Eight-Output 150kV
Trigger Generator L. Peng1, Q. Aici1, S. Fengju2, Y. Jiahui2
1Electrical Engineering, Xi'an Jiaotong University, Xi'an, China
2Pulsed Power, NorthWest Institute of Nuclear Technology, Xi'an, China
One developing direction of large drive sources by now is that tens of branchs, consisting of hundreds of pulsed power modules connected in series, operate in parallel to produce a high pulsed power required. One set of reliable trigger system providing multi-output trigger pulses with low delay jitter is crucial to synchronize so many pulsed power moduls reliably. To search a simple spark gap structure as the master switch of the developed trigger generator, a field-distortion three-electrode spark gap with a disc-shaped trigger electrode and its modified structure are fabricated and tested in this paper. The results demonstrate that the two gas spark gaps have similar breakdown delay and jitter when the charging voltage ratio is higher than 80%, but the modified has a wider operating voltage range. For its better operating performance and simplified structure, the modified spark gap has been chosed as the master switch, and a set of compact 150kV trigger generator with eight output cables is developed. Testing results indicate that the developed trigger generator in this paper provides a highest output voltage of about 150kV with a risetime of 10ns ( for four or less than four output cables ) or 16ns ( for eight output cables ), and a short output delay of less than 20ns with a jitter of less than 1ns. Similar operating performance data has been obtained through the primary synchronizing operation of two sets such trigger generators, which indicates that the novel developed trigger generator possesses a potential of a lot numbers operating in parellel to provide enough output trigger pulses for synchronizing hundreds of pulsed power modules.
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02P-18: Design and Performance Analysis of Two-Stage Mpc System
D. D. Zhang1, P. Yan1, J. Wang1, Y. Zhou1, 2 ,3 1Institute of Electrical Engineering, Chinese
Academy of Sciences, BeiJing, China 2Graduate School of Chinese Academy of
Sciences, BeiJing, China 3School of Automation and Electrical
Engineering, Tianjin University of Technology and Education, TianJin, China
A thorough theoretical analysis of a two-stage magnetic pulse compression (MPC) system is presented. The MPC system suffices to form 20kV, 70ns pulses across a 207Ω resistive load. Equivalent circuits for two consecutive operation stages of the compressor accounting for nonlinear processes in magnetic switches are analyzed．Both experiment and simulation results illustrated pre-pulse and reverse oscillation waveform on the resistive load. A thorough theoretical analysis of the cause of the pre-pulse and reverse oscillation waveform is presented. Equivalent circuits for final operation stage of the compressor accounting for pre-pulse and reverse oscillation waveform in Magnetic Switch (MS) are presented and analyzed. Simulation results illustrated how unsaturated inductance of MS and resistive load affected the amplitude of pre-pulse. To diminish the pre-pulse, unsaturated inductance of MS must be aggrandized which means a better ferrite core with higher differential permeability should be considered. Reverse oscillation waveform can be damped by increasing the inductance of freewheeling inductor which connected in parallel with the load．If a fast-recovering diode is applied as a substitute for the freewheeling inductor, current would mostly flow through the diode while charging, and almost no pre-pulse appears on the load, also the final operation stage matching improves，so that the pulse voltage reverse amplitude and damped oscillation duration are reduced drastically. The experimental results obtained with a resistive load are in fair agreement with the circuit calculation.
02P-19: Magnetic Characteristics of Saturable Pulse Transformer in Magnetic
Pulse Compression System D. D. Zhang1, P. Yan1, J. Wang1, Y. Zhou1, 2, 3
1Institute of Electrical Engineering, Chinese Academy of Sciences, BeiJing, China
2Graduate School of Chinese Academy of Sciences, BeiJing, China
3School of Automation and Electrical Engineering, Tianjin University of Technology
and Education, TianJin, China
Saturable pulse transformer (SPT) is finding increased use in Magnetic Pulse Compressor (MPC). SPTs are fabricated from ferromagnetic amorphous metal alloy ribbons. And the magnetic characteristics of these amorphous metals are discussed in relation to optimizing the performance of SPTs in such applications. To evaluate the magnetic performance of the magnetic core, a 1－cosine waveforms test stand is designed and built. The test stand is able to operate at modest repetition rates. The magnetization rates achieved in the experiments extend from 0.8 to 2.5 T/μs, corresponding to saturation times from 1 to 4 μs. The current through the core is calculated by voltage across the resistive load, and the loop voltage is picked up with a single wire loop and integrated by software. B-H curves are derived from the measured voltage and current waveforms. The differential permeability can be calculated from the slope of the B-H curve. Comparisons are presented for two Metglas cores which one is Mylar-insulated and the other not. Of the Mylar insulated core the trend is clear that increasing the packing factor, corresponding to increasing the winding tension, and more material in the core, tended to reduce the usable volt-second area and the eddy current loss together. Formulas are given for selecting core dimensions for IGBT switch protection. Finally, more practical energy transfer in SPT and the effects of leakage current are presented by applying custom characteristics to a two-stage MPC in Pspice simulation.
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02P-20: Power and Jitter Optimization of a 1.5 kV, 100 ps Rise-Time, 50 kHz
Repetition-Rate Pulsed Power Generator L. M. Merensky1, A. F. Kardo-Sysoev2,
A. N. Flerov3, D. Shmilovitz4, A. S. Kesar1 1Propulsion Physics Laboratory, Soreq NRC,
Yavne, Israel 2Ioffe PTI, St. Petersburg, Russia
3The Baltic State Technical University, St. Petersburg, Russia
4Faculty of Engineering, Tel Aviv University, Ramat Aviv, Israel
Sub-nanosecond pulsed-power generators are important for variety of applications such as ultra-wideband radars, laser driving, material characterization, water purification, and medical diagnostics and treatment. A 1.5 kV, 100-ps rise-time pulsed-power generator operating at a repetition frequency of 50 kHz was built and optimized through this work. The generator has three compression stages, two of which use fast high-voltage diodes. The first stage uses a power MOSFET that produces high voltage by breaking an inductor current. The second stage employs a 3 kV drift step recovery diode that cuts the reverse current rapidly to create a 1 ns rise-time pulse. In the last stage, a silicon-avalanche shaper is used as a fast, 100-ps closing switch. Experiments targeted to bring the circuit performance to optimum resulted in peak output power increase by 44%, namely from 45 kW to 65 kW. The experimental investigation showed that the optimization process can be used to reduce the shot-to-shot jitter from 20-ps to less than 13-ps. Theoretical model and its analysis will be presented.
02P-21: Silicon Diode Evaluated as Rectifier for Wide-Pulse Switching
Applications H. K. O’Brien1, A. Ogunniyi1, W. Shaheen2, C.
Scozzie1, V. Temple3 1US Army Research Laboratory, Adelphi, MD,
United States 2Berkeley Research Associates, Beltsville, MD,
United States 3Silicon Power Corporation, Clifton Park, NY,
United States Silicon diode chips, designed by Silicon Power Corporation, were explored as a more power-dense, lighter-weight replacement for traditional hockey-puk diodes in pulse switching applications. Army switching needs call for compact, high-power symmetric blocking pulse switches. While larger, wafer-scale silicon thyristors are capable of symmetric voltage hold-off, they are too bulky to meet the volume and weight requirements of vehicle-mounted systems. The Army Research Laboratory has demonstrated very promising switching performance with Silicon Powers Super-GTO, but the device cannot reliably block voltage applied in the reverse direction. The 3.5 cm2 silicon diode has the same area as the SGTO chip with reverse blocking capability up to 6 kV. Connected in series with the SGTO, it protects the switch by blocking negative voltage while still limiting the volume and weight of the overall package. The diode chip can be solder-mounted and does not require any high-pressure clamping. The diodes evaluated in this study were individually packaged at Silicon Power, then statically characterized and pulsed at the Army Research Laboratory. In series with the SGTO, the diode was pulsed with a half-sine shaped current of 5.5 kA with a pulse width of 1 ms. The action was calculated to be 1.6x104 A2s with a peak power of about 50 kW. As the systems voltage swung negative at the end of the forward current pulse, the diode rapidly transitioned from conduction mode to reverse blocking at 1.1 kV. Several diodes were individually pulsed in this circuit for 1000 shots at this level without increasing forward drop or reverse leakage. Diodes are being further evaluated in a crowbar configuration, clamping negative current ringing from the circuits inductance. This paper will include results of the ongoing rectifying and clamping pulse evaluations.
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02P-22: High Electric Field Packaging of Silicon Carbide Photoconductive
Switches C. Hettler, C. James, J. Dickens
Center for Pulsed Power and Power Electronics, Texas Tech University, Lubbock, TX, United
States
Photoconductive semiconductor switches (PCSS) made from semi-insulating (SI) silicon carbide (SiC) are promising candidates for high frequency, high voltage, and low jitter switching. However, existing switches fail at electric fields considerably lower than the intrinsic dielectric strength of SiC (3 MV/cm) because of the field enhancements near the electrode-semiconductor interfaces. Various geometries were identified which could reduce the electric field near the contact regions. The switches were simulated with various parameters and compared. In all cases, it was determined that a high dielectric constant (high-k) encapsulant is a crucial requirement that reduces high fields within the bulk material while inhibiting surface flashover. An assortment of high-k encapsulants were evaluated and a portion were subsequently tested in the lab. The observed dielectric strength and relative permittivity of the encapsulants are presented. Pseudo switches, employing sapphire substrates, were constructed and biased to electrical breakdown. The dielectric strength of the interface between the semiconductor and the encapsulant was tested and improvements were discussed.
02P-23: Balancing Circuit for a 5kV/100ns Pulsed Power Switch Based on SiC-JFET
Super Cascode J. Biela, D. Aggeler, B. Dominik, J. W. Kolar D-ITET, Power Electronics Laboratory, ETH
Zurich, Zurich, Switzerland
In many pulse power applications such as accelerators, medical systems, or radar systems there is a general trend towards solid state modulators based on semiconductor technology, as these offer adjustable pulse parameters, turn off capabilities and lower maintenance effort. There, high voltage, high current and fast semiconductor switches are required in order to achieve a high pulsed power and fast transients. Therefore, often high power IGBT modules or IGCT devices are used. Since these devices are based on bipolar technology the switching speed is limited and the switching losses are higher (e.g. tail current), what could limit the pulse repetition rate and the converter efficiency and increases the costs for cooling. Part of the switching speed limitation is caused by the parasitic elements of the power module packing as has been shown in [1, 2]. There, standard 4.5kV IGBT chips for traction applications are mounted in a special low inductive housing, which allows significantly faster switching transitions. In contrast to bipolar devices unipolar ones (e.g. SiC JFETs) basically offer a much better switching performance. Moreover, these devices enable high blocking voltages due to the larger bandgap of SiC. At the moment, normally on JFETs with 1.2-1.7kV [3, 4] and first test samples of 6.5kV devices are available. Moreover, in [3] normally off JFETs with a blocking voltage up to 1.8kV have been presented. In order to increase the blocking voltage capability the JFETs can be cascaded and connected in series with a low voltage MOSFET [4], so that the series connection behaves like a very fast, high voltage normally off switch, which is called Super Cascode. In [5] first results for the switching behaviour with resistive load have been presented. However, the turn on changed from a very fast transient at the beginning to a kind of RC behaviour resulting in a slower turn on transient. Therefore, in this paper a new balancing network of the Super Cascode is presented, which allows a turn on with a dv/dt of 100kV/µs and a 90% to 10% fall time of approximately 50ns. There, both the theoretical explanation of the operation principle and measurement results are included. With the new balancing network, additionally the transient voltage distribution is significantly improved. [1] M. Giesselmann et al., "High Voltage Impulse Generator Using HV-IGBTs", IEEE Pulsed Power Conference, June 2005 Page(s):763 - 766. [2] Powerex: http://www.pwrx.com.
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[3] M. Mazzola et al., “Inductive Switching with a 1-kA (saturation) Noramlly On SiC JFET Switch Module”, IEEE International Power Modulators and High Voltage Conference Proceedings. [4] R. Elpelt et al., "Serial connection of SiC VJFETs - features of a fast high voltage switch", REE. Revue de l'Electricite et de l'Electronique, pp. 60-68, 2004. [5] J. Biela et al. "5kV/200ns Pulsed Power Switch Based on SiC-JFET Super Cascodes”, IEEE International Power Modulators and High Voltage Conference Proceedings.
02P-24: Fast Optical Gating of 5kV Silicon Thyristors
H. D. Sanders, S. C. Glidden Applied Pulsed Power, Inc., Freeville, NY, United
States
Applied Pulsed Power has used laser diodes to improve the turn on time of standard commercial high voltage, high current silicon thyristors. Many applications currently using spark gap switches cannot take advantage of the long lifetime of a solid state switch such as a silicon thyristor due to the relatively long turn-on times of high voltage silicon thyristors. For electrically triggered devices, the rate at which the switch impedance falls is related to the transit time for carriers injected at the cathode to cross the base junction in order to start and build up the thyristor action, and is also related to the rate at which the entire area of the device is turned on. These issues limit the shortest pulsewidths to >300ns for practical applications. Switching losses are high at the shorter pulsewidths. Because the heat generated in the device by these losses cannot be conducted away from the device on the time scale of the pulse and because the lifetime of the device is strongly related to temperature, switching losses set an upper limit for the maximum power flow through the switch for a desired lifetime. The turn-on time of a silicon thyristor has been improved by generating charge carriers using solid state laser diodes. Optically pumping the silicon thyristor with sufficient energy at the appropriate wavelength generates a large number of charge carriers uniformly throughout the device. Previous experiments have tried to create devices based on fast optical gating of high voltage silicon thyristors. However, these used thick, expensive, prototype devices. We examined the use of standard commercial silicon thyristors. Using standard silicon devices, which have a thickness of 525 microns, allows the use of less expensive, more readily available light sources. This paper will describe how fast optical gating of silicon thyristors achieves turn-on times of less than 40ns to currents of several thousand amperes using commercial devices. Switching efficiency, power handling capability and overall system efficiency are increased. The turn on time as a function of optical energy and with the combination of both optical and electrical triggering are discussed. Work supported by DOE Grant No. DE-FG02-08ER85188.
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02P-25: Prediction of the Characteristics of Transformer Oil under Different
Operation Conditions W. A. Ahmed
Electrical Power and Machines, Helwan University, Faculty of Engineering, Cairo, Egypt
Power systems and transformer are intrinsic apparatus, therefore its reliability and safe operation is important to determine their operation conditions, and the industry uses quality control tests in the insulation design of oil filled transformers. Hence the service period effect on AC dielectric strength is significant. The effect of aging on transformer oil physical, chemical and electrical properties was studied using the international testing methods for the evaluation of transformer oil quality. The study was carried out on six transformers in the field and for monitoring periods over twenty years. The properties which are strongly time dependent were specified and those which have a great impact on the transformer oil acidity, breakdown voltage and dissolved gas analysis were defined. These properties can decide the transformer oil changes or purifiers to save the transformer from damage.
02P-26: Investigation of Corona Discharge Around 400 kV Conductors
Due to Extra-Low Frequency Electromagnetic Fields
S. Carsimamovic1, Z. Bajramovic1, P. Osmokrovic2, M. Veledar3, A. Carsimamovic3,
E. Aganovic3, S. Nuic4 1Faculty of Electrical Engineering, University of Sarajevo, Sarajevo, Bosnia and Herzegovina
2Faculty of Electrical Engineering, University of Belgrade, Belgrade, Serbia
3Independent System Operator in B&H, Sarajevo, Bosnia and Herzegovina
4Dalekovod, Zagreb, Croatia
Investigation of corona discharge around conductors of 400 kV overhead transmission lines Tuzla-Visegrad, Tuzla-Sarajevo and Tuzla-Ugljevik due to extra-low frequency (ELF) electromagnetic fields (EMF), are performed. These transmission lines are important objects for operation of electric power system of Bosnia and Herzegovina. Corona discharge is generally undesirable in electric power transmission, where it causes power losses, audible noise, electromagnetic interference etc. In this paper, it is given a review of the method for the electric and magnetic fields calculation of the power system high voltage elements. Electric field calculation is based on the method of equivalent charges, and the magnetic field calculation on the basis of Biot-Savart law. Two software are available. The first one is computer program EFC 400 and another is the program for the calculation of the electric and magnetic fields called Electric field and Magnetic field, developing by authors in the program package MATLAB. Verification of software program are performed on the basis of comparisons between field measurement results with calculation results of ELF EMF under lines on the heigh 1 m above earth.
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02P-27: Effect of Shielding on Reduction of the Eddy Current Losses in Power
Transformer Tank Wall M. Motalleb, M. Vakilian, A. Abbaspour
Electrical Engineering, Sharif University of technology, Tehran, Iran
The current sources in power transformers such as leads and windings, are sources of Eddy current losses. Due to these losses some parts of tank wall are subject to serious local overheating. It affects the safety and reliability of the expensive objects and power delivery. In first step the calculation of eddy current losses in tank wall is important. There are several methods for calculating the eddy current losses. In the next step offering the methods for reduction of the eddy losses, is important. There are various methods for reduction of these eddy current losses. One of them is internal shielding of transformer tank wall. In this paper the effects of tank wall shielding for reduction of the eddy losses, are introduced. At the first the effects of electromagnetic shields and magnetic shunts are introduced. Then, the eddy losses are calculated in tank wall of a type of three phase power transformer. Finally the reduced value of tank eddy losses after the shield installing is calculated.
02P-28: Experimental Study of Current Loss in a Post-Hole Convolute on a 1 Ma
Linear Transformer Driver M. R. Gomez1, R. M. Gilgenbach1, D. M. French1, J. Zier1, Y. Y. Lau1, M. R. Lopez2, M. E. Cuneo2,
M. G. Mazarakis2 1Plasma, Pulsed Power, and Microwave Lab -
Nuclear Engineering and Radiological Sciences Department, University of Michigan, Ann Arbor,
MI, United States 2Sandia National Laboratories, Albuquerque, NM,
United States Post-hole convolutes can be used to combine the current from several sources. This is particularly useful in large scale pulsed power devices such as Sandia National Laboratories' Z-Machine. The Z-Machine utilizes a double post-hole convolute to combine the current from four MITLs to one load. Current losses in the convolute region can be as high as 20% of the driver current. A 1 Mega-Ampere fast Linear Transformer Driver (LTD) has been assembled and tested into a resistive load at the University of Michigan. The Michigan Accelerator for Inductive Z-pinch Experiments (MAIZE) employs a transmission line with a modular load design. A single post-hole convolute load has been designed and is under construction for MAIZE. The intended diagnostics for the post-hole convolute experiments include an array of calibrated B-dot monitors and fiber optically-coupled spectroscopy. The current losses in the convolute region will be measured by subtracting the current measured downstream of the post-hole region from the sum of the currents measured upstream of the post-hole region. Location and timing of plasma gap closure in the region will be measured spectroscopically. Different materials were used for the anode and cathode, therefore the source of the plasma (and thus the source of gap closure) can be determined by the plasma composition. Plasma temperature and density will also be calculated using the spectroscopic measurements. Material presented will include Particle-In-Cell simulations using MAGIC PIC 3D, experimental design, and preliminary results. *MRG was supported by the Stockpile Stewardship Graduate Fellowship awarded by the KRELL institute in conjunction with the DoE/NNSA. JZ received a NPSC Fellowship funded by Sandia. This work was supported by U. S. DoE through Sandia National Laboratories award document numbers 240985, 768225, 790791 and 805234 to the University of Michigan. Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energys National Nuclear Security Administration under Contract DE-AC04-94AL85000.
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02P-29: Inductive Storage - Inductor for Capacitor Cell
N. A. Kovrizhnykh, A. A. Drozdov, R. S. Enikeev, B. E. Fridman, A. U. Konstantinov, U. L. Kryukov,
A. A. Malkov STC, D.V. Efremov Scientific Research Institute
of Electrophysical Apparatus, St.-Petersburg, Russian Federation
The inductor for the capacitor cell of the powerful capacitive energy storage [1, 2] is presented. The inductor is part of the Pulsed Forming Network of the capacitor cell. Energy stored in the inductor is 64 kJ, maximum voltage between terminals is 18 kV, maximal current is 60 kA. Three modifications of the inductor rated for 25 mcH, 40 mcH and 80 mcH have been developed. All three inductors are of a toroidal form, similar in dimensions and are wound with a rectangular wire. The main advantages of the developed inductor are a small leakage field, the absence of contact joints inside the inductor and the optimal scheme of counteraction to the electrodynamic forces acting on the turns. The paper presents the calculations of the stressed-strained state and strength of the inductor, as well as the results of the experimental studies of the inductor, including testing for the ultimate load capacity, testing of the high-voltage insulation for electric strength and testing of the cooling regime. The features of the inductor manufacturing technology are described. The inductor prototypes have passed the service life tests. 1. B.E. Fridman, et al. Energy Storage Capacitor Cell with Semiconductor Switches. In Proc. 2007 IEEE Pulsed Power Conf., p. 542- 545. 2. B.E. Fridman, et al. 0.5 MJ, 18 kV Module of Capacitive Ebnergy Storage. Abstract book of 2009 IEEE Pulsed Power Conf.
02P-30: Interferometric and Spectroscopic Measurements on a Triggered Plasma Opening Switch
Source A. G. Lynn1, M. Gilmore1, N. R. Devarapalli1,
M. E. Savage2, D. P. Jackson2, B. S. Stoltzfus2 1Electrical & Computer Engineering Dept.,
University of New Mexico, Albuquerque, NM, United States
2Sandia National Laboratories, Albuquerque, NM, United States
Plasma opening switches (POS) have a long history in the pulsed-power field. The key idea behind the POS is to use plasma as a high conductivity, low mass conduction channel that acts as a low impedance shunt until displaced by magnetic fields. The Triggered Plasma Opening Switch (TPOS) at Sandia National Laboratories is a unique device that exploits these plasma properties, and opens by applying a magnetic field to move the plasma on a ten-nanosecond time scale. The TPOS’s objective is to take the initial ~0.8MA (~250ns rise time) storage inductor current and deliver ~0.5MA at ~2.4MV (~10ns rise time) to a load of ~5-10 ohms. Configuration advantages include power gain (output power compared to either input power or trigger power), minimization of trigger input power as the result of using two stages in series, low output jitter, and low closed-state voltage drop. This two-stage design is novel and is the first to demonstrate command triggering of a plasma opening switch. The TPOS utilizes a set of pulsed flashboard-type plasma sources with a dipole guide magnetic field. Here we report measurements of switch plasma parameters obtained by a 120 GHz heterodyne tracking interferometer and visible spectroscopy. In particular, detailed plasma dynamics as a function of azimuthal position, flashboard driving voltage, and guide magnetic field strength are shown. The switch plasma is a key factor in determining switch performance, and these measurements are part of an effort to improve switch operation through better understanding of the switch plasma source spatial and temporal behavior. * Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.
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02P-31: Transient Processes Features in the Electric Circuit with the Ferromagnetic Open Switch
G. A. Shneerson, I. P. Efimov, A. V. Kononenko High Voltage Pulse Technique, Saint-Petersgurg State Polytechnical University, Saint-Petersburg,
Russian Federation
The ferromagnetic opening switch (FOS) function is based on the use of the solenoid with the ferromagnetic core with two orthogonal components of the magnetic induction (longitudinal and transversal). In the initial state, the core is saturated, and then it leaves the saturation state in result of switching-off of the magnetic biasing creating the transverse component. Then the magnet inductance sharply rises and the energy store circuit current switches. In the talk, the optimization problem for the core sizes and characteristics of the magnetic biasing control circuit is considered, that enables us to provide an effective jump of inductance at the minimum magnetic biasing current. Calculation of the switching process allows us to make the analysis and optimization of the FOS operating modes at wide range of parameters describing the magnet, the energy source and the load. Forming of the fast-rising current in the feed circuit for a small-induction load (small size single-turn coil) is considered as example. At the same time, a possibility to use FOS for sharp current breakage in devices for cold welding and for forming of the high-voltage pulses for sterilization of water solutions with the use of a strong electric field is investigated.
02P-32: Influence of Current-Breaking Switching Operations on Vacuum
Insulation P. Osmokrovic1, M. Jurosevic1, G. Ilic2, R. Maric1
1Faculty of Electrical Engineering, University of Belgrade, Belgrade, Serbia
2Electric Power Industry of Serbia (EPS), Belgrade, Serbia
Microscopic surface topography of contacts in vacuum switchgear undergoes substantial changes after various switching operations, which influence the inter-contact gap dielectric strength. According to the manner in which they change the topography of the contacts, switching operations are divided into those that cause contact welding or breaking of welded contacts, and those accompanied by the appearance of the switch-off arc. The action of the switch-off arc, or the current breaking, produces the change of vacuum switchgear contacts' surfaces through the following mechanisms: 1) erosion of contacts, 2) explosion of a conducting metal bridge during the development of the arc, 3) condensation of neutral metal vapors at contacts, and 4) microparticle emission from the melted regions on the surface of the anode and the cathode. Mechanisms 1), 2), and 3) dominate the emergence of a diffuse arc (i.e. the vacuum arc mode in which there is several small-current arcs in parallel, that don't produce a unified anode spot). Mechanism 4) is dominant in a compressed arc (i.e. the vacuum arc mode in which unification of anode spots into a single one occurs). The aim of this paper is to investigate the influence of current breaking on vacuum insulation. For that purpose, experiments with several types of vacuum switches have been conducted, in which the following parameters were varied: the type of arc (diffuse, compressed, and intermediate), the kind of contact material, and the parameters of the current-breaking procedure. The obtained experimental results have been statistically processed, and theoretically interpreted on both the microscopic level (considering electrical discharge mechanisms in vacuum insulation) and the macroscopic level (by pointing out their practical consequences for pulsed power application of vacuum switchgear).
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02P-33: Measurement of Arc Velocity in an Arc-Rotating Pulsed Power Switch
Based on B-Dot Probes H. Junjia, G. Rui
College of Electrical & Electronics Engineering, Huazhong Univ. of Sci. & Tech., Wuhan, China
The B-dot probes are installed in an arc-rotating pulsed power switch to measure the arc velocity in air at atmospheric pressure. B-dot probe is a small sensing coil based on Faradays law. Its voltage varies with the distance from the arc to probe. The probes are set under the gap and its axial is parallel to the arc moving direction. Six probes are set uniformly in a circle to obtain the arc velocity variation with current. The zero-crossing point of probe voltage signal is considered as the time when the arc above the probe. The variation of arc velocity is obtained from the experiment results, and the arc rotates at about 550m/s when the current is 20kA.
02P-34: Erosion and Lifetime Evaluation of Molybdenum Electrode under High
Energy Impulse Current T. K. Raychaudhuri, D. K. Pal, A. Upadhyay,
R. Thakur Metallurgy Division, TBRL, Chandigarh, India
The lifetime of the electrodes used in pulse current discharge with voltage level several 10s of kV depends on the erosion of electrode. There are many areas that have not been investigated and many areas that require additional study. Some studies have presented results related to erosion of electrode made of Cu-W, Ti, Graphite, Stainless Steel etc. There is little information available on erosion of Mo electrode. The mass loss and surface erosion of the electrode are related with the electrode material (conductivity, melting point, density and thermal capacity) and the impulse transferred charge (or energy) per impulse. Molybdenum was selected as electrode material considering these factors in addition to high erosion resistance due to high work function and better formability. The useful life of the electrode can be estimated based on the measured wear rates of electrodes expressed in units of μg/coulomb. The paper presents experimental work carried out to investigate the erosion characteristics of Mo electrode using 35 kV voltage and 10-15 kA current. The experimental results for Mo electrodes indicate less than 60 μg/coulomb for 5,000 coulomb transfers. For 10-15 kA current transfer with Mo electrodes we can take 1x105 shots with wear of 0.3 grams without appreciable local wear.
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02P-35: Streamer in High Gain GaAs Photoconductive Semiconductor
Switches H. Liu1, 2, C. Ruan1
1College of Physical Electronics, University of Electronic Science and Technology of China,
Chengdu, SiChuan, China 2College of Electronic and Information
Engineering, Chengdu University, Chengdu, SiChuan, China
The streamer formation and propagation is described in detail in high gain GaAs photoconductive semiconductor switches (PCSS). This theory is an extension of the collective impact ionization (CII) theory. This streamer model combining with the CII mechanism can explain the propagation velocity and the branch and the bend of streamer in high gain GaAs PCSS. The calculated results of photo-ionization effects and the propagation velocities of streamer imply that this model is reasonable because the results are consistent with the reported experimental observations.
02P-36: Comparison of Recovery Time and dV/dt Immunity for Si and SiC SGTOs
A. Ogunniyi1, H. K. O'Brien1, C. Scozzie1, W. Shaheen2, A. K. Agarwal3, V. Temple4
1US Army Research Laboratory, Adelphi, MD, United States
2Berkeley Research Associates, Beltsville, MD, United States
3Cree Inc, Durham, NC, United States 4Silicon Power Corporation, Clifton Park, NY,
United States
Present Army applications require switching components that can perform at pulse widths greater than 1 ms, while having relatively fast recovery transition times from the on-state to the off-state. This work investigates the recovery time (Tq) and the dV/dt immunity of silicon (Si) and silicon carbide (SiC) super gate turn-off thyristors (SGTOs). The Si SGTO was designed and fabricated by Silicon Power Corporation (SPCO). It has a chip area of 3.5 cm^2 with an active area of 2.0 cm^2 and is rated between 4 - 6 kV forward blocking. The SiC SGTO was designed by SPCO and Cree, while the fabrication was done by Cree. It has a chip area of .5 cm^2 with an active area of .36 cm^2 and is rated for 5 kV forward blocking and a drift region 60 μm thick. In this work, both the Si and SiC SGTO were pulsed at various charge voltages to determine the safe, repeatable peak current for both switches. Once the replicable peak current was determined for both switches, the next task was to determine the recovery time of both the Si and SiC SGTO based on the reproducible peak current. The recovery time (Tq) is the amount of dead time required for the switch to transition from the on-state to the off-state with confidence that the device will not arbitrarily turn on. Based on previous work done at ARL, it was discovered that the Si SGTO was not fully off after a 1 ms current pulse was applied to the switch. When high voltage was reapplied to the switch after 1 ms current pulse width, the device would turn back on even though no gate current pulse was applied to the gate terminal of the device. It was decided that gate-assisted turn-off was the appropriate solution to reduce the recovery time of the Si SGTO to ten's of microseconds time span. Applying - 10 V to the gate terminal after a 1 ms anode current pulse width, reduced the Tq to 25 μs. The SiC SGTO does not require gate-assistance and can obtain a Tq of 25 μs at a reproducible peak current at 1 ms pulse width. The SiC SGTOs were tested for dV/dt immunity with an overall voltage slope of 2.4 kV/μs and an instantaneous rise time of up to 8 kV/μs, whereas the Si SGTOs with - 6 V applied to gate termianal had an instantaneous rise time exceeding 13 kV/μs with an overall voltage slope of 8.4 kV/μs.
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02P-37: 12.6 kA / 20 kV / 300 Hz Reverse Conducting Solid State Switch for DeNox
/ DeSox Modulator A. Welleman, S. Gekenidis
ABB Switzerland Ltd, Semiconductors, Lenzburg, Switzerland
The presentation will show the specification, the design, the construction, and the test results of a solid state switch of which 32 pcs are used for DeNox and DeSox Modulators in a steel sintering production line. A closing switch which is operating at a charge voltage of 20 kVdc with a 300 Hz pulse repetition rate and 12.6 kA damped sine wave of 12 µs and 250 µs during arcing condition. The pulse current rise rate (di/dt) is more than 10 kA/µs. The paper will show the selection criteria of the semiconductor devices, and the optimization of the devices for this application. The complete ready-to-use closing switch is built up with a series connection of eight reverse conducting semiconductor devices with individual integrated optical triggered driver units which results in a compact stack construction with very low self inductance. Each device has a blocking voltage of 4500V and has a monolithic integrated freewheeling diode on the same silicon wafer. Because eight single wafer, press pack devices are used, the switch has a long term redundancy of one, and short term redundancy of two devices. This will assure a service friendly system with almost no maintenance. The switch is capable to operate continuous at a pulse repetition rate of 300 Hz and has to be cooled with oil or de-ionised water. Information will be also given on life-time expectancy based on earlier produced systems, redundancy and costs.
02P-38: Modular 30 kV IGBT Switch for Pulsed Power Applications
V. Zorngiebel1, E. Spahn1, A. Welleman2, S. Scharnholz1
1French-German Research Institute of Saint-Louis, 68301 Saint Louis Cedex, France
2ABB Switzerland Ltd. Semiconductors, 5600 Lenzburg, Switzerland
In this paper we present the development of a modular semiconductor switch, suited for pulsed power applications which require fast switching. The technical specifications we planned for a single module are a voltage capability of about 20 kV, a maximum current in the order of 250A and the capability of generating pulse widths of a few microseconds. The goal was to use two of these modules in a series connection, to built up a device with a blocking capability of at least 30 kV and a maximum current of 250 A. For the realization of the single 20 kV module IGBTs were considered as suited to meet the specifications. First we tested single devices to develop the IGBT driver unit and the trigger generator which is usable for a high turn on current pulse in pulsed power applications. Out of these tests IGBT dies with a maximum blocking voltage of 1700 V, a signal rise time of 100 ns, and a short circuit current rate of 650 A were selected from ABB. Because the single switch was planned with a maximum voltage of about 20 kV, a series connection of the IGBTs was necessary. For a synchronous switching of all the IGBTs an inductive coupled turn on and turn off driver unit was realized. This circuitry was developed in cooperation with ABB Switzerland Ltd, Semiconductors. The maximum value for the blocking voltage for the complete semiconductor switch was determined by the predefined size of the circuit board. Build up from the idea of a military use, we chose a circular board design with a diameter of 155 mm. So finally we were able to arrange 15 IGBT dies on the board. With a maximum blocking voltage of 1700 V of each device and a fixed DC link voltage of 70 % of this maximum, the limit for the module come to 18 kV. Using a load resistance of 50 Ohm the current was limited to a value of 360 A. This paper describes the development of the semiconductor switch incipient with the choice of the discrete IGBT dies, the development of the trigger generator, the active clamp protection circuit which is necessary for a safe switching at high voltages, and the IGBT driver unit. We show the first measurement results of a single pulse switching at 18 kV. Using a series connection of these single 18 kV modules, built up from ABB in an industrial standard, we will detail measurement results for tests at a maximum voltage of 30 kV, using two modules in series. In these tests the current was
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limited to 270 A. The results show the synchronous switching of the in series connected switches triggered off by the inductive coupled turn on and turn off driver.
02P-39: Performance Study of a Novel 13.5 kV Multichip Thyristor Switch
S. Scharnholz1, V. Brommer1, V. Zorngiebel1, A. Welleman2, E. Spahn1 1ISL, Saint Louis, France
2ABB Switzerland Ltd, Semiconductors, Lenzburg, Switzerland
The performance of a new ABB multichip thyristor switch has been investigated under different pulse conditions. The switch, jointly developed by ISL and ABB, consists of a stack of three thyristor wafers and one diode wafer, each having a diameter of 91 mm. Asymmetrically designed, each thyristor wafer provides a blocking capability of 4.5 kV. These devices are modified GCTs, specially designed for pulsed power applications. Packaged individually they are capable of a current rise rate (dI/dt) in excess of 20 kA/µs. This has been demonstrated for both, discrete devices and switching assemblies of up to three thyristors in series connection [1]. The 4.5 kV diode assures the switch to be reverse blocking on a reduced scale. Unlike first prototypes, which have been presented previously [1, 2], the wafer stack is now integrated in an industry standard, hermetically sealed, ceramic presspack housing. In this configuration the switch is specified for 13.5 kV repetitive peak off-state voltage and 100 kA pulse current (half sine wave, tp< 100 µs). To study the performance of these new devices a typical pulsed power circuitry was used. Initially, the device was stressed with a 35 µs half sine pulse, having a peak current of 100 kA maximum. Our attention focused on the determination of the maximum dI/dt of the device under different pulse conditions. In the initial condition, the maximum dI/dt amounted to 9 kA/µs without showing any abnormal behavior. A modified test condition with a half sine pulse width of 20 µs allowed increasing the di/dt to 12.5 kA/µs at a peak current level of 80 kA. In a subsequent test the peak current attained 100 kA and the dI/dt reached 14 kA/µs, but in this case the device failed. Additional tests, under again modified conditions, aimed at a further dI/dt increase at lower current levels. This time, the peak current amounted to only 9 kA, but the dI/dt reached 20,5 kA/µs. Subsequently, the device under test failed at a peak current level of 10 kA and a di/dt value of 24.5 kA/µs. In both fault cases only one of the three thyristor chips failed. The devices were still usable with a reduced blocking capability of 9 kV. Furthermore, a defect examination indicated that the failure mechanism is local overheating due to an inhomogeneous current distribution, probably caused by the high dI/dt value. So in conclusion, the devices showed a di/dt capability basically equal to that of individually packaged, 4.5 kV fast
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switching thyristors used in ISL pulsed power applications. [1] E. Spahn et al., “Novel 13.5 kV multichip thyristor with an enhanced dI/dt for various pulsed power applications,” 15th IEEE Int. Pulsed Power Conf., Montgommery, CA (USA), 2005. [2] S. Spahn et al.; “ 50 kJ ultra compact pulsed power supply unit for active protection launcher systems,” 14th Int. EML Symp., Victoria, CA (USA), 2008.
02P-40: The PFL "Squiggle:" An independent Monitor of Trigger and
Cascade Section Runtimes D. E. Bliss1, J. R. Woodworth1, T. G. Avila2,
H. J. Seamen2, M. E. Savage1 1Sandia National Laboratories, Albuquerque, NM,
USA 2Ktech Corporation, Albuquerque, NM, USA
The refurbished Z pulsed power driver has been operational since October of 2007 delivering a peak current of ~26 MA to the load. A critical component of the redesigned accelerator was the laser triggered gas switch (LTGS) with a maximum operating point of 6.3 MV, 820 kA and an overall 1-sigma timing jitter of 6-7 ns. We have identified a feature in the V-dot monitor on the Pulse Forming Line (PFL) downstream of the LTGS which is indicative of the closure of the trigger section of the switch. The PFL “squiggle” feature allows us to independently measure the runtime of the cascade and trigger sections and identify problems associated with the laser triggering of the switch, such as poor alignment or degrading transmission of the focusing lens. The squiggle also helps characterize the effect of changes in operating conditions and switch design. For the most recent design version of the LTGS, the trigger and cascade section runtimes (with ± 1-sigma jitter) are 6.3 ±0.8 ns and 47 ±6 ns respectively. The trigger and cascade section runtimes are not correlated suggesting that the trigger and cascade sections operate independently of each other.
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02P-41: Concept of a Two-Stage Liner Generator of Dense High-Temperature
Plasma V. A. Vasyukov, A. V. Ivanovskiy, A. I. Kraev,
A. A. Petrukhin, V. F. Rybachenko, A. A. Sadovoy, V. V. Zmushko, Y. A. Rezchikova
Russian Federal Nuclear Center, Russia Research Institute of Experimental Physics,
Sarov, Nizhniy Novgorod region, Russia
The paper will present the concept of a two-stage liner generator of dense high-temperature plasma. The generator comprises a cylindrical condensed liner driven by the current of an explosive magnetic generator to a velocity of more than 10 km/s. The internal volume of the acceleration chamber is pumped out to prevent current penetration under the liner and to create conditions for an acceleration of the working gas clouds from the edges and their convergence in the center of the chamber. Acceleration of the working gas in the form of the toroidal clouds from the edges towards the center of the chamber happens in the result of reduction of the chamber volume length realized with the help of the edge deflectors with a special calculated shape of the surface. The kinetic energy of high-velocity clouds of the working gas provides the required initial temperature for the stage of further compression of the working gas to high density and temperature realized in the center of the chamber.
02P-42: Pulsed Source of Energy on the Basis of a Helical Explosive Magnetic
Generator with a Built-in Current Opening Switch of Cumulative Type
P. V. Duday, V. A. Ivanov, A. I. Kraev, S. V. Pak, A. N. Skobelev, R. R. Zubaerova
Russian Federal Nuclear Center, Russia Research Institute of Experimental Physics,
Sarov, Nizhniy Novgorod region, United States
The paper gives a description of the experiments studying the operation of an explosive pulsed source of current with a microsecond rise front. The source comprises the helical explosive magnetic generator (HEMG) combined with a current opening switch of cumulative type. The operation of the opening switch is based on the conductor cutting by the jet streams formed at the impact of the wall of the HEMG’ central armature on the surface of the jet-former. The proposed design allows reducing the amount of the explosive and the dimensions as compared with a conventional design of the current source on the basis of HEMG and the explosive switches.
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02P-43: A Simple Operation Model of a Plasma Opening Switch with
Longitudinal Magnetic Field at the Erosion Stage A. V. Ivanovskiy
Russian Federal Nuclear Center, Russia Research Institute of Experimental Physics,
Sarov, Nizhniy Novgorod region, Russia
It is known that the introduction of a longitudinal magnetic field into plasma of a plasma opening switch (POS) improves its operation parameters significantly. The paper will present a simple calculation model making it possible to assess the efficiency of operation of the POS with application of a longitudinal magnetic field at the erosion stage. The application of this model provided the scaling ratios for the case of current peaking for the disk EMG with an electrically exploded foil current opening switch.
02P-44: A Device to Study the Properties of Substances at the Impact of the
Magnetically Driven Cylindrical Condensed Liner on the Targets at the
Velocity > or = 20 Km/s A. M. Buyko, Y. N. Gorbachev, A. V. Ivanovsky,
V. V. Pavliy, A. A. Petrukhin, N. I. Sitnikova, V. B. Yakubov
Russian Federal Nuclear Center, Russia Research Institute of Experimental Physics,
Sarov, Nizhniy Novgorod region, Russia
The paper will present the construction diagram of the pulsed power devices made on the basis of disk explosive magnetic generators (DEMG) with an electrically exploded foil opening switch of current (FOS). The devices are used to conduct research of the properties of substances loaded by the liner impact at the velocity of > or = 20 km/s. The element composition of the device and the peculiarities of the physical phenomena accompanying the operation of DEMG with FOS will be considered.
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02P-45: Considerations of a High Repitition Capillary Discharge Operated in Nitrogen as a Water-Window X-Ray
Microscope Source E. S. Wyndham, M. Favre, M. P. Valdivia,
J. C. Valenzuela Facultad de Fisica, Pontificia Universidad
Catolica de Chile, Casilla, Santiago de Chile, Chile
The Capillary Discharge is a very bright radiation source. When operated as a ns discharge at a peak current of order 10 kA and at a high repetition rate of order 200 Hz a very bright source at 2,8 nm is obtained. The source aperture is 0.8 mm. A successful source depends on intense axial electron beams generated by the transient hollow cathode mechanism. These e-beams greatly enhance the plasma X-Ray emission above that of a quasi Maxwellian distribution. Crucial to the practical realization of such a source is extremely low inductance geometry, effective heat removal and a ceramic wall and electrode heat loading that avoids ablation and impurities in the plasma. Observations of the time resolved optical spectrum from both ends of the plasma together with filtered X-ray diodes and a Faraday cup permit the verification of model parameters and also verify that the wall loading is not evaporating the surface. Four capillary length and internal diameters are explored. Furthermore the electrical circuit based on low cost IGBT’s is presented and a drive configuration that minimizes transformer magnetization losses that in other configurations is deposited in the plasma causing wall evaporation and contamination.
02P-46: Electron Emission Characteristics of Cardon-Nano Tubes
under Low Vacuum Conditions* S. Li, H. Kirkici
Electrical and Computer Engineering, Auburn University, Auburn, AL,, United States
In general, for plasma switches, the initiation of the plasma is critical and this is usually achieved by a “trigger” scheme. The seed electrons needed to initiate a breakdown can be generated by several means such as termionic emission or cold-cathode electron emission. The efficiency of these seed electron emission determines how well the plasma switch can close or open. In an early study we reported the electron emission characteristics of carbon-nano-tubes (CNT) at vacuum and discussed the possibilities of these materials as triggering material for pseudospark switches [1]. It is known that CNTs are prima candidates for cold-cathouse electron emitters. However, they can only operate at very low (vacuum level) pressures. In this work we present the electron emission characteristics of CNT and other materials, such as Zinc Oxide, tungsten, and copper in higher pressure rages that are the traditional operating pressures of pseudospark switches. We also present comparison of the electron emission measurements at several different pressures and before and after images of these materials obtained by SME. *This work is sponsored by AFOSR, with a grant number AF-FA9550-08-1-0050 [1] Shaomao Li; Koppisetty, K.; Kirkici, H.; “Characteristics of Cold-Electrode Emitter Materials for Pulsed Hollow Cathode Discharges,” Proceedings of the 2008 IEEE International Power Modulators and High Voltage Conference, Page(s):480 – 482, 27-31 May 2008
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02P-47: Beam-Plasma Interaction under Weak Coupling in Finite External
Magnetic Field E. V. Rostomyan
Institute of Radiophysics & Electronics National Ac Sci of Armenia, Ashtarack, Armenia
Plasma-filled microwave sources on relativistic electron beams have essential advantages as compared to vacuum ones [1, 2]. Their operation is based on stimulated emission of the oscillations of plasma-filled waveguide by the beam electrons. The devices correspond to cylindrical waveguide with thin annular plasma and spatially separated coaxial thin annular e-beam. The devices operate at higher beam current and the output frequency might be gradually changed by changing plasma density. In this configuration the beam-plasma interaction (BPI) has many specific features. It depends mainly on the level of overlap of the beam and the plasma fields. Along with the conventional case of maximal overlap of the fields (strong coupling [3]) the opposite case of weak overlap (weak coupling [4]) is possible also. The proper oscillations of the beam become very important. The physical character of BPI changes. The beam instability (BI) becomes due to the growth of negative energy beam wave (NEBW). The growth rate of this instability attains maximum under resonance of NEBW with plasma wave [1,4]. This wave-wave effect is called Collective Cherenkov Effect. The trends of increasing output frequency leads to decreasing of the skin depth in the walls of resonators. Their quality factor Q decreases and actually dissipation increases. In these conditions the role of dissipation increases [4-6] as it provides growth of the same wave. Even small dissipation leads to a new type of dissipative BI [4] with inverse proportional dependence on dissipation. Its properties and conditions of development are important additional factors that should be taken into account upon design of the devices. Up to now theory of plasma-filled microwave devices is developed mainly in strong external longitudinal magnetic field. However, the applicability conditions may be violated in real experiments especially in short wavelength range [7]. Description of devices based on cyclotron emission (anomalous Doppler Effect) is impossible at all. There is a necessity in theory of microwave devices in finite external magnetic field. Present investigation considers BPI in finite external longitudinal field in abovementioned geometry and substantiates new type dissipative beam instability with more critical (as compared to conventional) inverse proportional dependence on dissipation. It is shown that the new type of
dissipative beam instability, presented in [4], develops in finite external magnetic field also. Its properties should be taken into account under design of the devices. 1. M.V. Kuzelev et al. Plasma Phys. Rep. 26, 231,(2000); 2. M. Goeble et al. Phys Plasmas, 6, 2225, (1999). 3. E.V. Rostomyan Eur J Appl Phys 14, 177, (2001) 4. N.Karbushev, E.Rostomyan Phys Lett A,372(24), 4494, (2008) 5. E.V. Rostomyan. Europhys Lett, 77, 45001, (2007). 6. E.V. Rostomyan. Phys Plasmas, 7, 1595, (2000). 7. E.V. Rostomyan IEEE Trans Plasma Sci, 31, 1278 (2003) 8. I.N.Kartashov et al. Plasma Phys. Rep. 30, 56 (2004).
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02P-48: Magneto-Hydrodynamic Simulation of Z-Pinches Taking into
Account Multigroup Diffusion Radiation Transfer
V. D. Selemir, P. B. Repin, A. P. Orlov, B. G. Repin
Scientific and Technical Center of Physics, Russian Federal Nuclear Center - VNIIEF, Sarov,
Nizhny Novgorod Region, Russian Federation
Results of numerical simulation of irradiated Z-pinches using Lagrangian and 1D method and Eulerian 2D code FLUX-rz developed in Scientific and Technical Center of FRNC-VNIIEF are presented in the paper. In both approaches we use the magneto-hydrodynamic description of plasma taking into account the radiation transfer in the multigroup 3T-approximation. At simultaneous simulation of Z-pinches that differ in optical properties we paid special attention to comparison of obtained spectra with a stationary solution of a kinetic equation of the spectral radiation intensity transfer, coming out of a plasma column. An operation efficiency of the multi-group diffusion approximation at two-dimensional MHD simulation is demonstrated by an example of a Shot-52 experiment on Z-machine. Obtained calculated radiation spectrum that is generated by the pinch in the moment of peak power differs from a one-dimensional Planck distribution and matches well with absolute values of readings of a five-channel x-ray detector.
02P-49: Liner Experiments with Explosive Power Sources
V. D. Selemir, V. A. Demidov, P. B. Repin, A. P. Orlov, V. F. Ermolovich, A. S. Boriskin,
G. M. Spirov, I. V. Pikulin, A. A. Volkov, O. M. Tatsenko, A. N. Moiseenko, I. M. Markevtsev, S. A. Kazakov,
E. V. Shapovalov, B. P. Giterman, Y. V. Vlasov, M. A. Barinov, A. G. Repiev, E. G. Danchenko,
A. P. Romanov, Y. N. Lashmanov, A. V. Filippov, E. A. Bychkova, E. S. Rudneva, V. S. Pokrovsky,
D. S. Pokrovsky, A. R. Volodko Scientific and Technical Center of Physics,
Russian Federal Nuclear Center - VNIIEF, Sarov, Nizhny Novgorod Region, Russian Federation
Investigation results of multi-wire liners powered from a helical (MCG-200) and disk (DMCG-240) magneto-cumulative generators are presented in the paper. A current pulse of 5.3 MA at rise time of 400 ns is realized in one-cascade liners at their powering from the MCG-200 equipped with an explosive current opening switch. Parameters of a Z-pinch in this case are close to calculated ones: energy of x-ray radiation is 180 kJ in the pulse of ~20 ns length on a half height; a pinch plasma temperature is 65 eV. The DMCG-240 generators with an electric-explosive opening switch were used for powering of nested-array liner systems. The current in this case is 14 MA at the rise time from 1 up to 1.6 mks. Shortening of a current pulse front at other equal conditions leads to shortening of the pinch implosion time from 3.8 mks up to 2.5 mks, and of the x-ray radiation pulse length from 70 ns up to 55 ns. Also this leads to increase of the pinch plasma temperature from 40 eV up to 55 eV. Energy of the x-ray radiation is 500…800 kJ. An analysis of experimental results using 2D MHD code is carried out, the most probable scenario of the implosion of one- and nested- array liners is determined.
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02P-50: Two-Dimensional Magneto-Hydrodynamic Simulation of Z-Pinches
Considering Hall Effect P. B. Repin, V. D. Selemir, A. P. Orlov
Scientific and Technical Center of Physics, Russian Federal Nuclear Center - VNIIEF, Sarov,
Nizhny Novgorod Region, Russian Federation
A magneto-hydrodynamic model of an irradiating Z-pinch, which is a base for a two-dimensional (in cylindrical coordinates r-z) of a computer code FLUX-rz, developed by employees of STC FRNC-VNIIEF, earlier did not consider a Hall effect in a substance. In this paper we present results of the first stage of numerical research of a radial implosion of an annular plasma shell under effect of flowing current in it in the presence of Hall and drift components of an electric field in generalized Ohm law. A modified Hall MHD model of the Z-pinch remains in the frames of a quasi-neutral single-fluid approach to the plasma description; the necessity of application of an effective (decreased) coefficient of the plasma electric conductivity, conditioned by a helicon resistance, in the Euler FLUX-rz code is its peculiarity.
02P-51: The Role of Electron Heat Conductivity and Radiation Transport in
1D Simulations of Wire Explosions in Zebra Experiments *
S. F. Garanin, S. D. Kuznetsov All-Rusiian Research Institute of Experimental Physics (VNIIEF), Sarov, Russian Federation
Experiments at the Zebra facility at the University of Nevada, Reno, have been conducted to study the behavior of thick metal wires at ultrahigh magnetic fields. Currents of about 1 MA with 100 ns rise time were passed through 0.5 mm to 2 mm diameter aluminum wires. A number of diagnostic techniques used in the experiments provided data on radial expansion of wires and radiation of dense plasma formed on their surface by electrical explosion. The experiments have demonstrated that wires remain rather uniform lengthwise and can therefore be simulated numerically using 1D simulations. This paper considers the influence of radiation and heat conductivity on plasma formation processes. The simulations have shown that both processes electron heat conductivity and radiation transport should absolutely necessarily be taken into account for adequate description of plasma formation and wire dynamics in the experiments. Along with this, processes of electron heat conductivity magnetizing in the low-density plasma region have a minor effect on plasma formation processes and profiles of different quantities, and can therefore be ignored. It is also shown that variation of radiation transport factors by an order of magnitude weakly affects simulation results; and one can therefore expect that 1D simulations can adequately describe the experiments despite the existing uncertainty in transport factors. * This work is based on the results of the investigations conducted under the LANS/VNIIEF Contract #37713-000-02-35, Task Order 037.
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02P-52: Electrical Recovery after a Vacuum Discharge for Highly Repetitive
Plasma EUV Sources T. Yamamoto1, K. Nagano1, D. Yasui1,
A. Kuwahata1, S. Katsuki2, T. Sakugawa1, H. Akiyama1
1Graduate School of Science and Technology, Kumamoto University, Kumamoto, Japan
2Bioelectrics Research Center, Kumamoto University, Kumamoto, Japan
The discharge produced high energy-density plasmas are one of the candidates of high power extreme ultraviolet (EUV) sources for the next generation semiconductor nano-lithography. Laser ablation technology is often used to form a localized distribution of the target gas, resulting in the stabilization of the spatial distribution of hot plasmas that emit EUV of 13.5 nm with band width of 2 %. Presently the usable average EUV power of 50 W has been achieved by the highly repetitive operation of the LADPP scheme using the rotation disk electrode (RDE) technology [1]. It is necessary to increase the repetition rate to achieve 180 W for the high volume manufacturing (HVM) EUV sources. Key technologies to increase the repetition rate are the pulsed power generator technology, the thermal management, and also the recovery of the electrode gap, which is determined by the diffusion process of tin vapor. Here, we present the post-discharge phenomena of the laser assisted vacuum discharge. The discharges produce tin vapor and droplets and they stagnate between and around the electrodes. For the repetitive operation of the discharge, the space between and around the electrodes must be cleared sufficiently not to disturb the formation of laser assisted discharge plasma. We have investigated the recovery of hold-off voltage after the discharge. The second voltage pulse is applied to the electrode at a certain time after the discharge to evaluate the hold-off and breakdown voltages. The experiment shows that both the hold-off and the breakdown voltages are gradually increased and the recovery delays with increasing the discharge energy. For the discharge energy of 20 J and the operation voltage of 5 kV, the pulse repetition rate is limited below 5 kHz. For the small discharge energy of 5 J, the repetition rate can be increased up to 50 kHz. [1] E. Wagenaars, et al, Appl. Phys. Lett. Vol. 92, 181501 (2008)
02P-53: Gas-Filled-Capillary Discharge Experiment
J. Schmidt, K. Kolacek, O. Frolov, V. Prukner, J. Straus
Institute of Plasma Physics AS CR, v.v.i., Prague, Czech Republic
We have studied high-current capillary discharge as a prospective XUV laser source since 1998. Among others we have built two experimental apparatuses CAPEX (since 1998) and CAPEX-U (since 2005). On both these devices we have observed lasing at 46.9 nm (Ne-like argon line). Nevertheless, these devices are not only lasing at 46.9 nm but also they are used for testing a possibility of amplification at shorter wavelengths (below 20 nm), which have more practical applications (e.g. XUV lithography). CAPEX device is smaller and less powerful in comparison with CAPEX-U apparatus. On the contrary, CAPEX has faster capillary current rise-rate, which is more advantageous for reaching amplification below 20 nm. CAPEX device consists of a Marx generator (with up to 800 kV output pulse voltage), a pulse forming line, a gas-filled self-breakdown spark gap, and 20cm-long capillary with the inner diameter of 3 mm. Capillary discharge devices with either nitrogen-filled or methane-filled capillary are under examination at the present time. High resolved spectra will be obtained with the help of McPherson spectrometer.
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02P-54: Numerical Matching an EUV Laser of Recombination Type on
Hydrogen-like Ions of Nitrogen with a Pulse Energy Supply System
V. A. Burtsev, N. V. Kalinin Center of High Power engineering, Efremov
Scientific Research Institute of Electrophysical Apparatus, Saint Petersburg, Russian Federation
In this report results of numerical study of problems in matching electrodischarge EUV laser on hydrogen-like ions of nitrogen (λ=13.4 nm) with the pulse energy supply system consisting a generator of high-voltage pulses and a transmitting line. The length of this line was choose such that the waves reflected from the capillary load did not influence on processes occurring in the plasma load. The load itself represents a ceramic tube with close geometry of electrodes. Parasitic inductances of connection of the line with the discharge tube and the tube itself were considered. The carried out numerical experiments have shown, that effective input of energy in the load occurs when the total of ohmic and dynamic components of discharge resistance approximately matches with a wave resistance of transporting line. Thus, the wave reflected from the load carries away minimal energy. As in the given type of lasers for heating of a plasma column and in the further for radiation cooling of electrons, collapsing shock waves are used; this optimization should be carried out with account of interaction of shock waves with the current piston and with each other. Thus, it is possible to avoid an excessive removal of energy by reflected wave from the load and to minimize energy input into it for making effectively recombining active medium. It will help to realize short-wave EUV lasers including 13.4 nm lasers on hydrogen-like ions of nitrogen with enough high life time of discharge tubes. This work was supported by the grant 09-08-00160a of Russian Foundation for Basic Research
02P-55: A Nanosecond Discharge-Based X-Ray Source in Atmospheric Pressure
Air with a Subnanosecond Pulse Duration
V. F. Tarasenko, I. D. Kostyrya High Current Electronics Institute, Tomsk,
Russian Federation
X-ray radiation characteristics from a diode filled with atmospheric pressure air were investigated. A source of soft X-ray radiation with the FWHL less than 600 ps and exposure doze of ~3 mR per pulse has been created on the basis of a SLEP-150 pulser (maximum voltage amplitude of ~140 kV, FWHM of ~1 ns, and pulse rise time of ~0.3 ns). The main contribution into a registered exposure dose is shown to be made by X-ray quanta with the effective energy of ~7.5 keV. In comparison with the vacuum diode-based X-ray radiation sources, a source with atmospheric pressure gas diodes is easy-to-work and potentially has a long lifetime. When using a gas diode, there is no necessity to form a high-voltage subnanosecond pulse that essentially simplifies the design of a high-voltage pulse generator; as well as there is no necessity to use thin vacuum-tight foils for ejection of X-ray radiation that essentially raises the diode reliability and simplifies its design.
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02P-56: Theory and Experimental Measurements of Contact Resistance
W. Tang, M. R. Gomez, Y. Y. Lau, R. M. Gilgenbach, J. Zier
Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI, United
States
Electrical contact is an important issue for high power microwave sources, wire-array Z pinches, field emitters, and metal-insulator-vacuum junctions. Because of the surface roughness on a microscopic scale, true contact between two pieces of metal occurs only on the asperities of the two contacting surfaces. Current flows only through these asperities, which occupy a small fraction of the area of the nominal contacting surfaces. This gives rise to contact resistance [1]. We have developed a novel analytic theory of contact resistance of an asperity of transverse dimension (a) and finite axial length (h) connecting two metal blocks. For asperity of rectangular, cylindrical or funnel shape, we find that the contact resistance is of the form R[1+p(h/a)] where R is the corresponding h=0 a-spot theory limit of Holm [1] and Timsit [2], p has a simple form which we have verified against electrostatic code results. This higher-dimensional treatment links the contact resistance to the geometrical deformations in response to an applied pressure, and to the hardness of the material. Experimental measurements of the contact resistance of a single z-pinch wire were performed at the Plasma, Pulsed Power and Microwave Laboratory at the University of Michigan [3]. The measurements were taken for several wire types and contact methods. Traditionally strung wires (with a wire weight hanging from each end) had contact resistance values that were on the order of, or much greater than, the resistance of the wire itself. The contact resistance was significantly lower for all wires when metal gaskets were clamped over the wire at both contact points. In all cases, as the applied force normal to the contact point was increased, the contact resistance decreased. This agrees qualitatively with the theoretical predictions. Potential applications and extensions of the theory, such as the RF contact resistance, will be presented. This work was supported by AFOSR, AFRL, L-3, Northrop-Grumman and U. S. DoE through Sandia National Laboratories award document numbers 240985, 768225, 790791 and 805234 to the University of Michigan. Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energys National Nuclear Security Administration under Contract DE-AC04-94AL85000. MRG was supported by
the Stockpile Stewardship Graduate Fellowship awarded by the KRELL institute in conjunction with the DoE/NNSA. JZ received a NPSC Fellowship funded by Sandia. [1] R. Holm, Electric Contact (Springer-Verlag, 1967). [2] R. S. Timsit, IEEE Trans. Components Packaging Tech. 22, 85 (1999). [3] M. R. Gomez, J. C. Zier, R. M. Gilgenbach, D. M. French, W. Tang, and Y. Y. Lau, Review of Scientific Instruments Vol. 79, 093512 (2008).
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02P-57: Effect of Self Generated Magnetic Field on Double Layer Proton
Acceleration from Laser Irradiated Thin Metal Foils
V. K. Tripathi1, A. Sharma1, C. S. Tripathi2 1Physics Department, Indian Institute of
Technology Delhi, New Delhi, India 2Department of Physics, University of Maryland,
College Park, Maryland, United States
We propose a mechanism of self generated magnetic field from laser irradiated thin metal foils and study its role on laser driven double layer acceleration of protons. A circularly polarized finite spot size intense short pulse laser normally incident on an overdense thin metal foil produces a strong axial magnetic field and exerts a strong axial ponderomotive force on electrons. As the electrons are pushed forward and compressed, they leave behind an ion space charge, and a stage arrives when further compression of electrons stops and an electron ion double layer is detached from the foil Beyond this point the double layer is accelerated by the laser ponderomotive force. The cyclotron resonance effect of magnetic field improves the ion energy gain very significantly.
02P-58: Use of RHEPP-1 Repetitive Ion Beam to Simulate Exposure of IFE
Chamber Wall Materials to Repeated Reactor-Level Ion Fluences* **
T. J. Renk1, P. P. Provencio1, J. P. Blanchard2, S. Sharafat3
1Sandia National Laboratories, Albuquerque, NM, United States
2University of Wisconsin, Madison, WI, United States
3University of California, Los Angeles, CA, United States
The effects on materials subjected to pulsed ion beam exposures of 1000 pulses or more are being investigated on the 800 kV RHEPP-1 facility at Sandia National Laboratories, to simulate dry-wall exposures in future Laser Inertial Fusion Energy (IFE) reactors. On RHEPP-1, beams of helium or nitrogen are directed onto samples of tungsten, tungsten alloy, graphite, and silicon carbide either at room temperature or 600C. Fluences per pulse range from below melt to beyond ablation thresholds. Energetic ion fluxes represent 30% of the IFE fusion output per pulse in direct-drive reactor scenarios. (Neutron fluxes, representing most of the other 70%, cannot be readily simulated here.) Small-scale sample surfaces exposed to hundreds of ion pulses undergo thermomechanical stress as the near-surface zone expands and contracts against the non-expanding in-depth material. While a single IFE pulse does not cause the material to approach a fatigue-cracking threshold, repeated pulsings lead to stress fracturing, and formation of severe surface relief which takes hundreds of pulses to evolve. This roughening seen in poly-crystalline tungsten corresponds to a peak surface temperature (from heat-flow modeling) of 2,000 2,500K (i.e. below melt), depending upon whether the sample is heated or not. Alloying or heating of the tungsten to 600C reduces but does not eliminate these effects. Exposure to helium beam pulses appears to lead to additional surface damage that could be ascribed to He bubble formation and exfoliation. One possible way to mitigate these threats is to greatly increase the effective wall surface area, by use of a 3-D engineered surface. Exposures of W needles in single and array form show promise of reduced roughening and mass loss. The same model predicts a much higher surface stress for tungsten exposed to energy deposition expected in ITER Edge-Localized Modes (ELMs), e.g. 0.7 MJ/m2 deposited over 500 sec. The surface temperature reaches approximately the same value as indicated above for IFE pulses, but stresses and temperature gradients extend much deeper below the surface. This has implications for plasma-facing components exposed to
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Magnetic Fusion Energy (MFE) discharges in tokamaks. Both graphite- and silicon carbide-based materials erode at fluences below their respective sublimation points. The implications for both inertial and magnetic fusion energy reactors will be discussed. Measurements of surface roughening and removal, and SEM and TEM analysis will be presented, and compared to materials response predictions from heat-flow modeling. *Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Co., under US DOE Contract DE-AC04-94AL85000. ** Supported by NRL through the HAPL Program by the U.S. Department of Energy, NNSA, DP.
02P-59: Optimal Design of a Grid Cathode Structure in Spherically
Convergent Beam Fusion Device by Response Surface Methodology
Combined with Experimental Design H. Ju, B. Kim, H. Hwang, K. Ko
Electric engineering, Hanyang university, Seoul, South Korea
Neutron production is very important to apply fusion energy through Spherically Convergent Beam Fusion (SCBF) device as a portable neutron source and its rate is deeply dependent on the ion current[1]. Also the ion current has a close relation with the potential well structure inside a grid cathode. This paper proposes a design method by varying the size of cathode rings to get an optimal grid cathode structure in SCBF device. The optimization is based on the response surface methodology (RSM)[2] and the full factorial design (FFD) is also applied to raise the precision of optimization and to reduce the iteration of experiment in the application of the RSM. Finite Element Method-Flux Corrected Transport (FEM-FCT) method is employed to calculate the ion current. From the optimized model, the higher ion current is calculated and the deeper potential well is observed. [1] M. Ohnishi, Y. Yamamoto, M. Hasegawa, "Study on an inertial electrostatic confinement fusion as a portable neutron source ", Fusion Engineering and Design, Vol. 42, pp. 207, 1998 [2] X. K. Gao, T. S. Low, Z. J. Liu, S. X. Chen, “Robust Design for Toque Optimization Using Response Surface Methodology” IEEE Transactions on Magnetics, vol. 38, no. 2, pp. 1141, 2002
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02P-60: Analyses of the Gyroelectric Plasma Rod Waveguide
S. Asmontas1, L. Nickelson1, T. Gric1, R. Martavicius2
1Terahertz's Electronics Laboratory, Semiconductor Physics Institute, Vilnius,
Lithuania 2Electronic System Department, Gediminas
Technical University, Vilnius, Lithuania
Semiconductor plasma rod waveguides are widely used in the large variety of devices [1, 2]. Here we present an electrodynamical analysis of the semiconductor n-InSb plasma rod waveguide. The waveguide radius is r = 1.5 mm and the electron concentration of the semiconductor n-InSb is N = 10^19 m-3. We have admitted that electrophysical parameters of n-InSb are the following: relative permittivity of lattice , an effective mass, mobility of the electrons. The magnetic induction of the external constant magnetic field is equal to 1T. We are going to give here the dispersion characteristics and the electric field distributions of the main HE11, and the higher EH11, HE12, HE13 modes propagating in the semiconductor plasma waveguide. The electric field distributions were calculated at frequencies which are close to the cutoff frequencies of every investigated mode. We have made a conclusion that only the main mode electric field concentrates in the small centre aria of the plasma rod waveguide. The electric field strength lines of the plasma waveguide turned in comparison with the same field lines of analogical isotropic waveguide. So the semiconductor plasma rod waveguides can be used as phase shifters like other more complicated constructions of phase shifters [3]. References: [1] A. Eroglu and J. K. Lee, Wave propagation and dispersion characteristics for a nonreciprocal electrically gyrotropic medium. Progress In Electromagnetics Research, Vol. PIER62, p. 237-260, 2006. [2] L. Nickelson and V. Shugurov, "Singular Integral Equations' Methods for the Analysis of Microwave Structures", VSP Publishing International Science Publishers, Leiden-Boston, 348 p., 2005. [3] R. L. Espinola, T. Izuhara, M.-C. Tsai, and R. M. Osgood, Magneto-optical nonreciprocal phase shift in garnet silicon-on-insulator waveguides, Optics Letters, Vol. 29, No. 9, 941-943, 2004.
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O16: Electromagnetic Launchers and Pulsed Power Systems
Colonial
Wednesday, July 1 15:00-17:00
O16-1: Research on a Plasma-Driven Railgun for Economical Access to Low
Earth Orbit
D. A. Wetz, F. Stefani, I. R. McNab, J. V. Parker Institute for Advanced Technology, The
University of Texas at Austin, Austin, TX, United States
For the last four years, the Institute for Advanced Technology has been working on the development of a plasma-driven electromagnetic launcher for economical access to space [1]. The research is focused on overcoming setbacks experienced in the early developmental days of plasma-driven electromagnetic launchers, which prevented researchers from obtaining muzzle velocities in excess of 6 km/s [2]. The possibility of achieving muzzle velocities in excess of 7 km/s with an electromagnetic launcher make its use attractive and cost efficient means for launching small (~10 kg) microsatellites into low Earth orbit. For that reason, the research being performed is funded as part of a Multidisciplinary University Research Initiative (MURI) by the United States Air Force Office of Scientific Research (AFOSR). In the summer of 2007, a muzzle velocity of 5.2 km/s was achieved with no evidence of restrike arcs or bore ablation, the effects of which are believed to limit the velocity of plasma railguns to no more than 6 km/s. Since then a series of modifications have been made to the railgun bore to improve its performance and lifetime. Some of those modifications, and the experimental results obtained as a result, are discussed here. 1. D. Wetz, F. Stefani, J. Parker, and I. McNab Advancements in the Development of a Plasma-Driven Electromagnetic Launcher, 14th International Electromagnetic Launch Symposium (EML), Victoria, BC, Canada, June 10-13, 2008. 2. J. V. Parker, Why plasma armature railguns dont work (and what can be done about it), IEEE Trans. Mag., vol. 25, no. 1, pp. 418-424, 1989.
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O16-2: Development of a 40-Stage Distributed Energy Railgun
R. W. Karhi1, M. Giesselmann1, D. A. Wetz2, J. Diehl1
1Center for Pulsed Power and Power Electronics, Texas Tech University, Lubbock, Texas, United
States 2Institue for Advanced Technology, University of
Texas, Austin, Texas, United States The development process pertaining to the design, fabrication, and testing of a 40-stage free-running arc synchronous distributed energy railgun is presented. Investigation of this type of system will determine the effectiveness of a distributed energy scheme to suppress the plasma restrike phenomenon and increase plasma armature railgun performance [1]. Determined by a computer simulation, the proposed system will have a 1cm x 1cm square bore cross section and an individual stage length of 15.24 cm producing a total rail length of 6 meters for 40 stages. A free-arc is utilized to relieve the financial burden of a large stored energy facility. A velocity of 8 km/s is desired to emulate conditions during a high altitude microsatellite launch. To achieve this velocity, pulsed power in conjunction with a low pressure (~ 10 Torr) air environment is required. The pulsed power supplies 15 kJ of energy to provide an armature current (~ 50 kA) for 1 millisecond. A real-time feedback control system will accurately release the stage energy upon arc arrival. Control of the temporal variance pertaining to the trigger timing becomes a vital parameter for successful arc propagation. Experimental data collected from a 7-stage prototype distributed system is discussed which will mimic the design and operation of the first 7 stages associated with the 40-stage railgun. The copper rail length is 1.2 m long with a 1 cm x 1 cm square bore cross section and a 15.24 cm stage length. Each distributed energy stage contains a 750 micro Farad capacitor bank, a 1.5 micro Henry inductor, a phase controlled thyristor with an anti-parallel diode, and a driver board for triggering. The armature is formed using a plasma injector that is powered by a 40 kV Marx generator. Diagnostics for this examination include rail B-dot probes as well as independent Rogowski coils for each stage. Data collected from the rail B-dot probes will be used to measure the armature position and velocity as a function of time. There is no target velocity for this prototype; repeatable energy module operation, accurate stage triggering, and arc propagation toward the muzzle are the main areas focus. Outcomes of these initial experimental results will aid the development of the 40-stage system.
[1] J. V. Parker, “Why Plasma Armature Railguns Don’t Work”, IEEE Transactions on Magnetics, Vol. 25, No. 1, January, 1989, pp. 422. * Work supported by the AFOSR MURI for low cost access to space
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O16-3: Modeling of the Contact Resistance and the Heating of the
Contact of a Multiple Brush Projectile for Railguns with the Finite Element Code
ANSYS M. I. R. Coffo, J. Gallant
Weaponsystems and Ballistics, Royal Military Academy, Brussels, Belgium
When metal fiber brush armatures are used in electromagnetic railguns, contact transition has to be avoided. Therefore we want to simulate the current and temperature distribution in a multiple brush projectile for an augmented railgun to determine the heat load at the contact between the brushes and the rails. For the simulations the finite element code ANSYS is used. This code allows a combination of an electromagnetic and a thermal analysis. In this paper the simulation model we used for the study of the heat load at the contact between the rails and the current brush is presented. The modeling of the contact resistance between the rails and the fiber brushes plays a key role in this model. To simulate this contact resistance, we adapted the resistivity in a thin layer between the rails and the fiber brushes. The thickness of this layer and the resistivity are the main parameters for the electromagnetic analysis. For the thermal analysis, the thermal conductivity plays a key role. The influence of these parameters is studied and the results are discussed in this paper.
O16-4: Rail Current Reduction by Series Augmentation of an EM Railgun
M. J. Veracka1, C. N. Boyer2, J. M. Neri3, T. G. Engel4
1Tactical Electronic Warfare, Naval Research Laboratory, Washington, DC, United States
2Titan Group, L3 Communications, Reston, VA, United States
3Plasma Physics, Naval Research Laboratory, Washington, DC, United States
4ECE, University of Missouri, Columbia, MO, United States
The Naval Research Laboratory has been investigating the use of an electromagnetic railgun to launch expendable decoys for aircraft and shipboard applications. The launcher must have long rail life, consistent and controllable velocity and be capable of firing salvos of rounds. To maximize the magnetic pressure pushing the armature and minimize launch current, the launcher rails have been augmented with additional turns. Augmentation is used to increase the efficiency because this application requires the projectile to have a low velocity. Each augmenting turn is electrically in series and carries the full gun current. To reduce resistive losses, each augmented rail is composed of three mutually insulated conductors in parallel. The peak launch current scales as n-1, where n is the number of augmenting turns. Thus, for a double- augmented launcher, the peak launch current should be approximately one half that of the single-augmented gun. This scaling is experimentally observed when the augmenting turns are closely coupled to the inner rail and to each other. To obtain long rail life, several rail materials were tested including Copper 110, nickel plated copper and diffusion strengthened Glidcop. Bore riders were incorporated into the projectile to deposit a thin, lubricating coating to the rail ahead of the moving armature. Additional methods employed to extend rail life include embedding Elkonite launching pads into the rails at the breech to reduce startup damage and embedding current absorbing shunts in the rails at the muzzle to eliminate arcing when the projectile exits the railgun. Diagnostics include in-bore start-up position measurement, down bore b-dot loops, breech and muzzle voltages, current measurement and exit velocity measurement using laser beam interruption. In addition, a method was devised to record projectile position as a function of time for the first few milliseconds of motion.
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O16-5: Effect of Resistance Modification on EML Capacitor Bank Performance
B. M. Huhman1, J. M. Neri1, T. Lockner2 1Plasma Physics Division, US Naval Research
Laboratory, Washington, DC, United States 2Electrophysics Applications, LLC, Albuquerque,
NM, United States
The U.S. Navy is considering the development of an electromagnetic launcher (EML) for surface-fire support and other missions [1]. The Naval Research Laboratory has initiated a program to develop and test materials to achieve these fire rates and lifetimes [2]. The U.S. Naval Research Laboratory has assembled a facility to develop and test materials for the study of barrel lifetime in electromagnetic launchers (EML) for surface-fire support and other missions [3]. The pulsed power system utilizes several modules that can be individually triggered to shape the output current pulse. Each bank module consists of capacitors from General Atomics Electronics Systems. The switching thyristors and crowbar diodes are from ABB. A series inductor is used to limit the peak current, isolate modules from each other, and ensure the current is delivered to the test system. Several launch events have been performed, and the pulsed power systems have operated as intended [3]. The capacitor bank modules were originally designed with minimum output resistance to obtain the maximum L/R decay time into the launcher. Modification of a module to allow for a variable output resistance is highly desirable to modify the output waveform of the bank module system, such as limiting the late-time current. NRL has designed resistance packages that can be easily inserted into a specific bank to modify the damping of the current. The effect of the resistance will be shown at various power levels and the resulting effect on switch action, capacitor voltage reversal, and output current will be demonstrated. Computer modeling of the modifications will also be discussed. [1] I. R. McNab, et al., “Development of Naval Railgun”, IEEE Trans. Magn., vol. 41, no. 1, pp. 206-210, Jan. 2005. [2] R.A. Meger, et al. “Analysis of Rail Surfaces From a Multishot Railgun”, IEEE Trans. Magn., vol. 41, no. 1, pp. 211-213, Jan. 2005. [3] J.M. Neri and B.M. Huhman, “Operation of a 5-MJ Capacitor Bank for EML Materials Testing,” presented at the 2007 IEEE Pulsed Power Conference, Albuquerque, NM.
O16-6: Experimental Investigation of the Operation of an Electrodynamic Spraying
Setup G. A. Shvetsov, Y. L. Bashkatov, A. G. Anisimov,
V. V. Zykov, V. P. Chistyakov Lavrentyev Institute of Hydrodynamics,
Novosibirsk, Russian Federation
The attractiveness of the electrodynamic spraying method using an electric discharge in an inert gas atmosphere is due to a number of potential advantages, for example, the absence of fire-hazardous combustible gases and the relative purity of the spraying process. The experimental electrodynamic spraying setup consists of a small-scale plasma accelerator with a power supply, a gas system, and a control system. The coaxial accelerator has an earthed sectioned barrel with an inner diameter of 20 mm and the total length of all sections up to 1m. The power supply comprises a charging unit with a voltage up to 5 kV and a capacitor bank up to 800 µF. The maximum supply energy is up to 10 kJ. The gas system of the setup consists of a container with the working gas, a buffer container, and barrel and back-flow valves. The computer system for operating the electrodynamic spraying setup comprises a personal computer, remote-controlled units for opening metering valves, and an ignition pulse generating unit. This paper presents results from experimental studies of the dependences of the accelerating gas flow parameters and the spraying efficiency on the capacitor power supply parameters and discharge time. The maximum shock wave velocities in the working gas were higher than 2.5 km/sec at a mass velocity over 2 km/sec, which allows the spraying of various powders. The spraying experiments with Ni, Co, Cu, and Mo have shown the possibility of achieving good adhesion of the spray powders to the base material. The potentials of the method are discussed.
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O16-7: Genesis: A 4 MA Programmable Pulsed Power Driver for Isentropic
Compression Experiments S. F. Glover1, K. W. Reed1, G. E. Pena1, L. X. Schneider1, J. P. Davis1, C. A. Hall1, R. J. Hickman1, K. C. Hodge2, J. M. Lehr1,
D. J. Lucero3, D. H. McDaniel1, J. G. Puissant2, J. M. Rudys1, M. E. Sceifford1, S. J. Tullar2,
D. M. Van De Valde3, F. E. White2 1Sandia National Laboratories, Albuquerque,
United States 2Ktech Corporation, Albuquerque, United States
3EG&G, Albuquerque, United States
Enabling technologies are being pursued at Sandia National Laboratories that will improve the performance, flexibility, and efficiency of advanced pulsed power systems. In particular these technologies are addressing the need for a new pulsed power system named GENESIS, which is capable of precision current pulse shaping up to 4 MA and variable risetimes of 200-600 ns. This development has been propelled by the need to study material properties under dynamic high pressure conditions using magnetically driven isentropic compression experiments (ICE), a technique that benefits greatly from precision current pulse shaping. Genesis is designed to produce temporally controlled material pressure waves up to 400 kbar in support of equation of state analysis. Programmable pulsed power systems for ICE present significant challenges in system design and optimization. Low impedance ICE loads require extremely low driver impedance to reduce system stress and improve system performance. In addition to the impedance requirements an unprecedented switch operating range is required by the 240 sequentially triggered high voltage switches. This paper provides an overview of a new pulsed power system named GENESIS along with discussion on the use of genetic optimization techniques for pulse shaping and system design, serviceable solid insulator systems, and highly dynamic switch performance.
O16-8: Analytic Model and Experimental Study of the UNM Reltron Pulsed Power
System S. Soh, E. Schamiloglu, J. Gaudet, R. L. Terry
Electrical & Computer Engineering, University of New Mexico, Albuquerque, New Mexico, United
States
The UNM reltron is driven by a 2 stage bipolar 396 J Marx generator [1] capable of generating a maximum voltage of 120 kV. The output voltage pulse has a rise time less than 0.25 μs and a pulse width of 1-4 μs, depending on the load impedance. The pulse width is controlled by a crowbar switch that shunts current away from the load. An analytic model of the Marx generators charging and discharging process has been developed. The charging process begins with constant current charging followed by constant voltage charging. Solutions describing both charging processes and the switching criteria from constant current to constant voltage is given in this presentation. The charging current, capacitor voltage and the charging time have been found to be consistent with experiments [2]. For the discharging process, a system of 1st order Ordinary Differential Equations (ODE) is used to describe the process [3]. The system of ODEs is solved numerically and the Marx voltage and current curves are obtained. The calculated voltage across the resistive load is compared with the load voltages measured in experiments. The load voltage rise time, voltage droop and fall time obtained from the model matches the experimental data quite well. The resistive load in the model describing the discharging process is replaced with a planar diode that has an ideal cathode whose emission is space-charge-limited [4]. The 1D space charge effects is modeled using Child Langmuirs Law in cylindrical coordinates [5]. The output current of the Marx generator model is compared to beam current simulated using MAGIC. REFERENCE [1] H. Bluhm, Pulsed Power Systems (Springer, Berlin, 2006). [2] S.H. Choi, Characterization of Electron Beam Modulation in a Compact Reltron High Power Microwave Source, (M.S. Thesis, University of New Mexico, July 2002). [3]E. Kuffel, W.S. Zaengl, and J. Kuffel, High Voltage Engineering Fundamentals, 2nd Ed. (Newnes, Woburn, MA, 2000). [4] M. Reiser, Theory and Design of Charged Particle Beams (John Wiley and Sons, New York, NY, 1994). [5] S. Humphries, Jr., Charged Particle Beams (John Wiley and Sons, New York, NY 1990).
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O17: Pulsed Power Capacitors Ballroom
Wednesday, July 1 15:00-17:00
O17-1: High Energy Density Capacitors for Pulsed Power Applications
F. W. MacDougall1, J. B. Ennis1, X. H. Yang1, R. Jow2, J. Ho2, S. Scozzie2, R. A. Cooper1,
J. E. Golbert1, J. F. Bates1, C. Naruo1, M. Schneider1, N. Keller1, S. Joshi1
1General Atomics Electronic Systems, Inc., San Diego CA, United States
2US Army Research Laboratory, Adelphi MD, United States
The improvement in the performance of high energy density capacitors used in pulsed power has accelerated over the past few years. This can be attributed to increased research work in this field sponsored by the US Army Research Laboratory in support of the US militaries needs. Cost effective capacitors operating at 3 J/cc are now available to the US Military. This series of capacitors has been designated Type CMX by GA-ESI. The capacitors have a nominal 1000 shot life at the highest energy density but have a much longer life expectancy at slightly lower energy densities. The capacitor development effort will be discussed. Both short term and long term testing of this new generation of high energy density capacitors will be presented.
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O17-2: Achieving High Dielectric Constant Polymer/BaTiO3
Nanocomposites at Low Filling Ratios J. Wang1, L. Zhu1, 2, Q. Wang3, J. Huang3, W. Li3 1Institute of Materials Science and Department of
Chemical, Materials and Biomolecular Engineering, University of Connecticut, Storrs,
CT, United States 2Department of Macromolecular Science and
Engineering, Case Western Reserve University, Cleveland, OH, United States
3Agiltron, Inc., Woburn, MA, United States
Polymer-ceramic nanocomposites have attracted great interests for electronic applications, such as transducers, piezo-sensors, hydrophone materials, because they combine good processability of polymers and high dielectric constants of ceramics together. The inorganic filler can play an important role in the dielectric properties of nanocomposites, especially they can enhance the dielectric constant (er). However, a high ceramic loading is usually required to achieve high enough dielectric constant, which will dramatically reduce the processability and dielectric breakdown strength. In this work, we employed a three-phase model proposed by Vo et al. to coat 50-nm BaTiO3 nanoparticles with tetrameric Cu-phthalocyanine as a finite interfacial layer, because it possesses a very high apparent dielectric constant (er=10^4-10^5), in a poly(vinylidene fluoride-co-hexafluoropropylene) matrix. High apparent dielectric constants (even higher than theoretical predictions) were achieved at relative low volume fractions.
O17-3: Sub-Microsecond, 50 kV-Class Pulsed Power Capacitor Design and Life
Testing M. T. Domonkos1, S. Heidger1, D. Shiffler1,
T. Tran1, D. Brown2, C. W. Gregg2, K. Slenes3 1AFRL/RDHP, Air Force Research Laboratory,
Kirtland AFB, NM, United States 2SAIC, Albuquerque, NM, United States
3TPL, Inc., Albuquerque, NM, United States
Pulsed power capacitor development has historically been driven by laboratory plasma sources and the accelerator community. The primary design consideration has been reliable electrical performance. As a result of this consideration and the sheer quantity of stored energy, most capacitor designs have been based on polymer films. The capacitors are adapted from power systems designs, tend to be large, and are substantially derated to achieve reliable operation. Compact pulsed power for sub-microsecond, 0.1 to 1 MV applications have typically adapted commercial-off-the-shelf capacitors into Marx generators to scale the voltage appropriately. While extensive effort is invested in the improvement of dielectrics for pulsed power capacitors, few of the advances have made their way to packaged devices in the 50 kV-Class with greater than 0.1 J/cc capacity. This paper describes efforts to examine capacitor design and life rating to achieve gains in energy density for compact systems. In the design of capacitors, this investigation revisited capacitor design choices that contribute to limit the energy density, specifically the electrode arrangement, dielectric insulation margins, and derated shot life. A developmental polymer-ceramic nano-composite dielectric enabled design, fabrication, and testing iterations to be completed relatively rapidly. The capacitors consisted of multilayer electrodes around which the dielectric was cast from a slurry and then cured. The electrodes were shaped to maximize the use of the capacitor volume based on electrostatic modeling. The finished capacitors were DC high potential tested to at least 75 kV. They were then inserted into a nearly critically damped test circuit for life testing. The discharge length was either 100 ns or 500 ns, depending on the load resistance. The capacitors were charged to 20 to 50 kV with a DC high voltage supply, and the capacitors were driven up to 5 pulses per second. Combined with data collected by colleagues at Sandia National Laboratories, the capacitor lifetimes showed the expected dependencies on charge voltage and discharge rate. Consequently the results have enabled characterization of the capacitor energy density as a function of shot-life and discharge rate. Changes in the manufacturing have yielded ~100x improvements in pulse discharge life.
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O17-4: High Energy Density Film Capacitors
S. Zhang1, Q. Zhang1, S. Rockey1, B. Zellers1, C. Zou2
1Strategic Polymer Sciences, Inc., State College, PA, United States
2MRI, Penn State University, University Park, PA, United States
High energy density film capacitors have been developed by using a modified high quality polyvinylidene fluoride resin. Capacitor film with thickness from 2 micrometer to 10 micrometer has been produced using low-cost melt-extrusion and biaxial orientation process at commercial scale. Metallized film capacitors with capacitance from 10 uF to 100 uF were wound and tested. The prototype capacitors exhibit high dielectric breakdown strength, high energy density, fast discharge, long lifetime, and graceful failure characteristics. The high energy density film capacitors can be used for military weapon system, medical defibrillators, and other pulsed power applications.
O17-5: Advanced Multilayer Ceramic Capacitors with High Energy Density for
Pulse Power Applications S. Kwon1, W. Hackenberger1, J. Day2
1TRS Technologies, State College, PA, United States
2Calramic Technologies LLC, Reno, NV, United States
A new approach to pulse power ceramic capacitors has been developed. Breakdown strength of multilayer ceramic capacitor is governed by complicated issues such as defects in the dielectrics, dielectric grain size, electric field induced strain and electrode configuration. Current processing efforts are focused on reducing the defects in the dielectric for high breakdown strength in pulse power applications. Capacitors made from antiferroelectric (AFE) ceramics shows increasing capacitance value with voltage. This unique property allows one to put a very efficient capacitive filter in a very small package. Many different sizes of multilayer ceramic capacitors with 0.5 to ~7 uF capacitance and rated voltage ranging from 1000 to ~3000V have been successfully fabricated. Resulting capacitors showed energy density of 1~3J/cc and exhibited 1500~2000 Amp peak current in 1~2 us discharges. These results were achieved with capacitors that were only 0.07cc in total volume. In this paper, pulse power application results of various ceramic capacitors will be presented along with temperature and electric field dependence of the dielectric properties.
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O17-6: Monte Carlo Modeling of Heterogeneities in Ceramic, Polymer, and
Composite Capacitors E. Furman, G. Sethi, B. Koch, M. T. Lanagan
Materials Research Institute, Pennsylvania State University, University Park, PA, United States
High and reproducible dielectric breakdown strength is essential requirement for high energy pulse power capacitors. It is important to understand which features are especially important in determining breakdown strength, and modeling of the dielectric breakdown complements experimental work in achieving deeper insights into dialectical breakdown. We have performed Monte Carlo modeling of breakdown strength in ceramics, polymers, and layered organic/inorganic composites. In the case of ceramics, the effect of uniform and nonuniform porosity on the breakdown strengths indicated that both the level and type of porosity influence ultimate strength. Furthermore, porosity has stronger influence on the breakdown strength as the pore size-to-dielectric thickness ratio becomes larger. It was also determined that the prediction of the model agrees well with experimentally observed area dependence of dielectric breakdown of commercial capacitors. In the case of semicrystalline polymers, the modeling work strongly suggests positive contribution to the breakdown strength from the interfaces between crystalline and amorphous phases. This conclusion was reached through the comparison of Weibull modulus obtained from the experimental breakdown strength measurements of biaxially oriented polypropylene capacitors with that of Monte Carlo modeling of the same dielectrics. Only in the case of interfaces dominating the breakdown strengths there was a good agreement between experimental and modeled Weibull modulus. The modeling work also indicate that unlike ceramics for which infinite Weibull modulus is theoretically achievable for the defect-free dielectric, in the case of semicrystalline dielectrics the Weibull modulus is finite in all cases, and is controlled by polymer microstructure and capacitor geometry. Graceful failure was models for semicrystalline polymers and modeling indicates strong interaction between benefits of graceful failure and microstructural features of semicrystalline polymer. Heterogeneities play an important role in determining the intrinsic and extrinsic breakdown strength of the dielectrics that are inherently heterogeneous, such as semicrystalline polymers. In the case of layered ceramic - polymer composites we focused on understanding tree propagation as a function of the dielectric contrast between the layers and the placement of high K ceramic layer within the composite. Both dielectric contrast and
placement of the layer turned out to be important in determining required time for sample destruction. Interestingly, these effects are observed in the electrostatic modeling without introduction of defects and space charges at the interfaces. A comparison of breakdown in heterogeneous ceramics, polymers, and composites indicates a great diversity and richness of observed behavior. In particular, both the beneficial and detrimental effects of heterogeneity were deduced from the modeling, and we hope that this work will motivate further research in developing high energy materials.
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O17-7: Analysis of Capacitor Performance by Repetitive Pulsed
Charge Discharge Operation S. Heidger1, E. Loree2, M. Domonkos1,
D. Shiffler1, W. Hackenberger3 1Air Force Research Laboratory (AFRL/RDHP),
Kirtland AFB, NM, United States 2Loree Engineering, Albuquerque, NM, United
States 3TRS Technologies, State College, PA, United
States
A comparison of the performance, lifetime and failure modes of polymer and ceramic capacitors in pulsed and DC operation was made using experimental grade packaged capacitors rated from 500-2000 volts and 100 nanofarads to 2 microfarads. An Ultravolt 2C24-P-250 regulated DC/DC converter was operated at 200 milliamp constant current, to charge the test capacitors to full voltage. Then they were discharged through a load resistance that was varied from 5 to 50 ohms. Test capacitors were subjected to charge/discharge cycles by alternately triggering IGBTs at repetition rates that were varied from 1 to 200 Hertz. Capacitor lifetime was evaluated as a function of discharge rate, repetition rate, and average external temperature rise during testing. Slow charging and discharging of capacitors was accomplished using a simple test circuit consisting of a 2kV power supply that was both regulated and filtered, connected to a 100,000 ohm resistor and the test capacitor through a high voltage relay. The charge and discharge waveforms were analyzed to evaluate dynamic changes in capacitance and loss as a function of cycles and time. Performance, lifetime and failure modes in pulsed operation were compared to that in DC and low voltage, AC operation. These results and an explanation of the observed differences are reported.
O17-8: Application of a Quasi-Static EM Solver to Optimization of Low Inductance
Film Capacitors S. Qin, S. A. Boggs
Institute of Materials Science, University of Connecticut, Storrs, CT, United States
A film capacitor consists of numerous “windings” connected in series and parallel, as necessary to achieve the desired voltage and capacitance rating. The discharge properties of such a capacitor are determined by the equivalent series resistance (ESR) and equivalent series inductance (ESL) of the overall assembly, which are determined by the properties of the individual windings combined with the structure into which they are assembled, as well as the frequency dependent impedance of the load. A quasi-static electromagnetic solver has been used to compute the frequency-dependent ESR and ESL of structures which minimize capacitor inductance. The properties are frequency-dependent as a result of the variation in the relative values of resistive and inductive impedances with frequency, which changes the current path in the structure and, therefore, the magnetic field (and resulting inductance) generated by current flow. The ultimate objective is to optimize film capacitors for ns discharge applications and compute the discharge characteristics into a given load using a transient, quasi-static electromagnetic solver which will represent accurately during discharge the frequency-dependent properties of the system.
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O18: Power Electronics and Systems
Chinese Room
Wednesday, July 1 15:00-17:00
O18-1: A High-Power High Voltage Power Supply for Long-Pulse Applications
A. Pokryvailo, C. Carp, C. Scapellati Spellman High Voltage Electronics Corporation,
Hauppauge, NY, United States This paper describes a concept and physical demonstration of an ultra-high efficiency, small size and low cost 100 kV, 100 kW high voltage power supply designed for long-pulse applications (units of milliseconds to DC operation). Key technology includes a modular HV converter with energy dosing inverters, which operate at about 50 kHz and have demonstrated an efficiency of 97.5% in a wide range of operating conditions. The inverters output voltages are phase-shifted, which yields an exceptionally low ripple of 1 % and a slew rate of 3 kV/us combined with low stored energy that is less than 10 J at maximum voltage. Modular construction allows easy tailoring of HVPS for specific needs. Owing to high efficiency, small size is achieved without turning to liquid cooling. Controls provide standard operating features and advanced digital processing capabilities, along with easiness of accommodating application-specific requirements. HVPS design and testing are detailed. It is shown that the ripple factor is inversely proportional to the number of modules squared. Experimental current and voltage waveforms indicate virtually lossless switching for widely-varying load in the full range of the line input voltages, and fair agreement with circuit simulations. The overall efficiency is as high as 95 % at full load and greater than 90 % at 20 % load, with power factor typically greater than 93 %.
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O18-2: High Power, High Efficiency, Low Cost Capacitor Charger Concept and
Demonstration A. Pokryvailo, C. Carp, C. Scapellati
Spellman High Voltage Electronics Corporation, Hauppauge, NY 11788, United States
A 20 kJ/s, 10 kV, 1 kHz repetition-rate technology demonstrator design and testing are described. The goal of the development was combining high performance and versatility with low cost design and good manufacturability. This goal was met using an energy-dosing converter topology [1], [2] with smart controls adapting the switching frequency in such a way as to ensure zero-current switching for all possible scenarios, keeping maximum duty cycle for high power. Thus, the switching is accomplished at a frequency of up to 50 kHz employing relatively slow IGBTs with low conduction losses. High efficiency allows all-air cooled design that fits into a standard 6Ux19” rack. Design guidelines are reviewed. Comprehensive PSpice models accounting for numerous parasitic parameters and mimicking controls for the frequency variation were developed, and simulation results are presented. Together with analytical tools, they predicted a pulse-to-pulse repeatability of +/-0.15%; the measured figures are +/-0.25% and +/-0.4% for short- and long-term operation, respectively, at peak charging and repetition rate. Repeatability analysis is briefed upon here, and to larger extent, in an accompanying paper. Test methods are described. Typical current and voltage traces and results of thermal runs are presented. [1] Kurchik, B.Z., Pokryvailo, A., and Schwarz, A.N., "Converter for Storage-Capacitor Charging", Plenum Publishing Corporation, Translated from Pribory i Teckhnika Éxperimenta, No. 4, pp. 121-124, 1990. [2] Wolf, M., Pokryvailo, A., “High Voltage Resonant Modular Capacitor Charger Systems with Energy Dosage”, Proc. 15th IEEE Int. Conf. on Pulsed Power, Monterey CA, 13-17 June, 2005, pp. 1029-1032.
O18-3: ILC Marx Modulator Development Program Status
C. Burkhart, T. Beukers, M. Kemp, R. Larsen, K. Macken, M. Nguyen, J. Olsen, T. Tang
SLAC National Accelerator Laboratory, Menlo Park, CA, United States
A Marx-topology klystron modulator is under development as an “Alternative Conceptual Design” for the International Linear Collider project. It is envisioned as a lower cost, smaller footprint, and higher reliability alternative to the present, bouncer-topology, “Baseline Conceptual Design.” The application requires 120 kV (+/-0.5%), 140 A, 1.6 ms pulses at a rate of 5 Hz. The Marx constructs the high voltage pulse by combining, in series, a number of lower voltage cells. The Marx employs solid state elements; IGBTs and diodes, to control the charge, discharge and isolation of the cells. The developmental testing of a first generation prototype, P1, has been completed. This modulator has been integrated into a test stand with a 10 MW L-band klystron, where each is undergoing life testing. Development of a second generation prototype, P2, is underway. The P2 is based the P1 topology but incorporates an alternative cell configuration to increase redundancy and improve availability. Status updates for both prototypes will be presented.
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O18-4: Design Considerations for a PEBB-based Marx-topology ILC Klystron
Modulator K. Macken, T. Beukers, C. Burkhart, M. Kemp,
M. Nguyen, T. Tang SLAC National Accelerator Laboratory, Menlo
Park, United States
The concept of Power Electronic Building Blocks (PEBBs) has its origin in the U.S. Navy during the last decade of the past century [1]. As compared to a more conventional or classical design approach, a PEBB-oriented design approach combines various potential advantages such as increased modularity, high availability and simplified serviceability. This relatively new design paradigm for power conversion has progressively matured over the last 10 years and its underlying philosophy has been clearly and successfully demonstrated in a number of real-world applications [2]. Therefore, this approach has been adopted here to design a Marx-topology modulator for an ILC environment where easy serviceability and high availability are crucial. This paper discusses various design considerations including power cycling capability, cosmic ray withstand, fault tolerance, etc. of a 32-cell Marx modulator to power an ILC klystron; 120 kV, 140 A, 1.6 ms pulses at a repetition rate of 5 Hz. Details of the design of a PEBB Marx cell are included. In addition, the concept of nested droop correction is introduced and demonstrated. [1] T. Ericsen. 'Power Electronics Building Blocks - A systematic approach to power electronics.' In: Proceedings of Power Engineering Society Summer Meeting, Seattle, WA, 16-20 July 2000. Piscataway: IEEE, 2000. Vol. 2, p. 1216-1218. [2] P.K. Steimer, B. Ødegård, O. Apeldoorn, S. Bernet, and T. Brückner. 'Very high power IGCT PEBB technology.' In: Proceedings of IEEE Power Electronics Specialists Conference, Recife, Brazil, 12-16 June 2005. Piscataway: IEEE, 2005. P. 1-7. Work supported by the U.S. Department of Energy under contract DE-AC02-76SF00515
O18-5: A Hybrid Solid State Marx Magnetron Modulator
R. L. Cassel Stangenes Industries, Inc., Palo Alto, CA, United
States
A Solid State Marx combined with a standard pulse transformer results in a low cost and flexible modulator for magnetron application. The unique features of the Solid State Marx of variable pulse width, fast adjustable rise times, changeable amplitude and high reputation rate makes it ideally suitable for a dynamically flexibility modulator. The Magnetron and its pulse transformers can be operated at considerable distances from the modulator and power source by using a matching cable, which results in significant installation flexibility. The unique properties of the Solid State Marx enable the core bias and heater supply to be located at the modulator without additional interconnecting wiring to the magnetron. The result is a simplified cable plant and operation. The paper will delineate this unique design of the Solid State hybrid modulator and its performance
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O18-6: Transient Thermal Response of Pulsed Power Electronic Packages
N. R. Jankowski1,, 2, F. P. McCluskey2 1Sensors and Electron Devices Directorate, U.S. Army Research Laboratory, Adelphi, MD, United
States 2Department of Mechanical Engineering,
University of Maryland, College Park, MD, United States
Traditional methods of improving the thermal management of power electronic devices have involved enhancing convective performance, improving material thermal conductivity, and reducing the number of layers in the package thermal stack. These techniques can significantly decrease thermal resistance between the cooling medium and the semiconductor device which in turn allows for lower temperature or higher power density operation. However, with respect to pulsed or transient power electronics systems, a problem with the aforementioned improvements is that they only address the steady state portion of the package thermal impedance. In fact, the same changes being made to improve steady state performance may actually degrade the ability of the cooling system to mitigate temperature fluctuations caused by high rate transient conditions. A two-part numerical investigation using finite element validated thermal equivalent circuits was performed on the transient thermal response of several power module packaging schemes. First, the propagation of a thermal pulse through the package stack and the ability for the junction temperature to respond to or be mitigated by an applied convection at the back of the package was examined. This response is found to be strongly dependent on the relative duration of the applied pulse. In conventional packaging schemes, the package thermal transit time relative to pulse length can render junction temperature rise completely insensitive to applied convection. Because such factors have been driving the trend for tighter integration of the cooling mechanism into the package and closer to the device junction, the second part of the study examined the effect of such improvements on the thermal package. Specifically, numerical models were used to investigate the design tradeoff between thermal resistance and thermal capacitance in the structure. Tighter integration of the cooling mechanism and reduction in packaging material decreases the package’s thermal time constant which reduces thermal dissipation time, achieves a faster return to steady state, and enables a sustainable increase in overall pulse rate. However, the reduced thermal capacity associated with volume reduction decreases the package’s ability to absorb the energy of the
pulse, and can result in higher relative peak temperatures during the pulse for certain load frequencies despite the improved steady state performance. Comments will be made regarding the need for pulsed device package design to include an understanding of the tradeoffs involved in attempting to reduce device temperatures to improve performance and reliability. As certain package fatigue failure modes are more dependent on thermal gradients and temperature excursions than average temperature, this behavior could become the dominant package design consideration. In addition, current attempts to manage the thermal-resistance and capacitance tradeoff through proper engineering of high thermal capacity materials will be discussed.
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O18-7: A Hierarchical Control Architecture for a PEBB-based ILC Marx
Modulator K. Macken, C. Burkhart, R. Larsen, M. Nguyen,
J. Olsen SLAC National Accelerator Laboratory, Menlo
Park, United States
The idea of building power conversion systems around Power Electronic Building Blocks (PEBBs) was initiated by the Office of Naval Research in the mid 1990s [1]. A PEBB-based design approach is advantageous in terms of power density, modularity, reliability, and serviceability. It is obvious that this approach has much appeal for pulsed power conversion including the ILC klystron modulator application. Referring to [2], a hierarchical control architecture has the inherent capability to support the integration of PEBBs. This has already been successfully demonstrated in a number of industrial applications in the recent past. This paper outlines a hierarchical control architecture for a 32-cell PEBB-based Marx-topology ILC klystron modulator. As described in [3], the control in PEBB-based power conversion systems can be functionally partitioned into (three) hierarchical levels; system level, application level and hardware level. This has been adopted here. Based on such a hierarchical partition, the interfaces between these various levels are clearly identified and defined and, consequently, are easily characterized. In addition, control, protection and communication requirements are addressed. Finally, concepts for the hardware manager, executing low-level hardware oriented tasks, application manager, handling higher-level application-oriented tasks, and system level controller, dealing with system control and monitoring functions, are detailed. [1] T. Ericsen. 'Power Electronics Building Blocks - A systematic approach to power electronics.' In: Proceedings of Power Engineering Society Summer Meeting, Seattle, WA, 16-20 July 2000. Piscataway: IEEE, 2000. Vol. 2, p. 1216-1218. [2] T. Ericsen, Y. Khersonsky, P. Schugart, and P. Steimer. 'PEBB - Power Electronics Building Blocks, from concept to reality.' In: Proceedings of International Conference on Power Electronics, Machines and Drives, Dublin, Ireland, 4-6 April 2006. London: IET, 2006. P. 12-16. [3] F. Wang, S. Rosado, and D. Boroyevich. 'Open modular power electronics building blocks for utility power system controller applications.' In: Proceedings of IEEE Power Electronics Specialists Conference, Acapulco, Mexico, 15-19 June 2003. Piscataway: IEEE, 2003. Vol. 4, p. 1792-1797. Work supported by the U.S. Department of Energy under contract DE-AC02-76SF00515
O18-8: Nanosecond High Voltage Pulse Generators PROTEUS Without High-
Voltage Gas or Semiconductor Switch A. N. Maltsev1, I. R. Arslanov2, V. V. Chupin2, A. Y. Ivanov2, D. Y. Kolokolov2, I. N. Lapin2
1Institute of Atmospheric Optics Russian Academy of Sciences, Tomsk, Russian
Federation 2Electrodinamic Systems & Technologies, LLC,
Tomsk, Russian Federation
The main goal in development of the “PROTEUS” line high-voltage pulse generators was to make power supplies for new type plasma generators of Atmospheric Discharge with Runaway Electrons (ADRE) [1]. The main parameter for such a power supply is a short enough (1 ns and less) pulse leading edge by the voltage amplitude about 50 kV -100 kV. It is the first singularity of this power supply in combination with average power about 1 kW and more. The pulse repetition frequency must be more than 1 kHz. The second singularity of the “PROTEUS” line power supply is long enough operation life period (tens of thousands of hours) and low cost. It is possible to reach by absence of any gas or semiconductor high-voltage switch and by superposition of electric line voltage inversion with initial pulse shaping to 1 microsecond duration by low voltage semiconductor switch (IGBT). The output high voltage pulse formation is produced on the base of magnetic switches only with several voltage transformations, compressions and doublings. Voltage pulse leading edge (and half-height) duration, as well as pulse amplitude for different models are the following. «Proteus»-I: 150 (300) ns at 25 kV on 300 Ohm load. «Proteus»-II: 15 (30) ns at 120 kV (600 Ohm) or 30 kV (50 Ohm). «Proteus»-III 1 (4) ns at 50 kV (50 Ohm). Three modes of operation are possible – single pulse, pulse train with necessary number of pulses, and continuous operation with pulse energy up to 0.5 J, and regulated pulse repetition frequency up to 2 kHz. This unique combination of the “PROTEUS” generators output parameters is made in compliance with electric standards including overheat, overstrain and short circuit protection. Three types of the power supply control are used - manual (control panel with digital indicator), and external (analog trigger pulse or computer based control). High-voltage pulse generators of PROTEUS line can be used for excitation of various types of electric discharges in dense gases (DRE, DBD, corona, streamer), and also - in liquids and solid-states by operation both in laboratory and industrial conditions [2]. Typical areas of application are the electrical discharge plasma processing and gas laser technologies. There are
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possible to use PROTEUS line generators also as a power supply unit for geo- and some other type radars (with wavelength from tens of meters up to about 1 cm by DRE); for electroporation technologies in bio-technological, food, and pharmaceutical industries; for water treatment, air purification, etc. References 1. A. N. Maltsev, “Fast electron, ion, atom, UV and X-Ray radiation beams, as well as ozon and/or other chemically active molecules generation in dense gases”, Patent # 2274923 of Russian Federation, with priority since September 01, 2003. 2. http://www.edynamicst.com/en/technologies_en
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THURSDAY
JULY 2
O19: Breakdown Phenomena in Gases, Liquids & Solids
O20: Industrial, Commercial, & Medical Applications
03P: Industrial, Commercial, & Medical Applications and Explosive and Compact Pulsed Power
04P: Pulsed Power Sources, Pulsed Power Systems, Diagnostics, and Power Electronics & Systems
O21: Industrial, Commercial, & Medical Applications
O22: Bulk Optical Switches and Components
267
O19: Breakdown Phenomena in Gases, Liquids & Solids
Ballroom
Thursday, July 2 9:15-11:15
O19-1: Insulator Surface Flashover Due to Ultra-Violet Illumination
J. B. Javedani, T. L. Houck, D. A. Lahowe, G. E. Vogtlin, D. A. Goerz
Engeineering, Lawrence Livermore National Laboratory, Livermore, CA, United States
The surface of an insulator under vacuum while under electrical stress will flashover when illuminated by ultra-violet (UV) radiation depending on the insulator size and material, insulator cone angle, the applied voltage and insulator shot-history. A testbed comprised of an excimer laser (KrF, 248 nm, ~16 MW/cm2, 30 ns FWHM,), a vacuum chamber (low 1.0E-6 torr), and a negative polarity dc high voltage power supply (up to -60 kV) was assembled for insulator (1.0 cm thick) testing. An in-house designed and calibrated fast capacitive probe (D-dots, >12 GHz bandwidth) was embedded in the anode electrode underneath the insulator to determine the time of flashover with respect to time of UV arrival [1]. The location of the probe below the UV illuminated section of the insulator. The probe gave highly resolved temporal data and charge data between the UV arrival time and surface flashover time. A beam splitter and commercial energy meter were used to measure the UV fluence for each pulse. The testbed was utilized for testing of several candidate insulator materials, e.g. High Density Polyethylene (HDPE), Rexolite, Macor and Mycalex, at different cone angles. The +45 degree Rexolite insulator required more UV fluence to flash; minimum critical fluence of ~13.0 +/- 4.0 mJ/cm2, while holding up to 60 kV of DC charge [2]. In order to understand the physical mechanism leading to flashover, we further experimented with the +45 degree Rexolite insulator by masking portions of the UV beam to illuminate only half of the previously expose surface; 1) the half nearest the cathode, or 2) the half nearest the anode. The results were then compared with the base case of full-beam illumination. We found that the time for the insulator to flash was shorter, less UV fluence required, for the cathode-half beam illumination leading to the conclusion that the flashover mechanism for the UV illumination is initiated from the cathode side of the insulator. Qualitatively stated, the shielding of the cathode triple point against UV is more important than the anode triple junction in the design of vacuum insulators. [1] T.L. Houck, et. al. “Fast Diagnostic For Electrical Breakdowns in Vacuum”, LLNL-TR-402609, March 2008. [2] J. B. Javedani, et. al. “Ultra-Violet Induced Insulator Flashover” 28th IEEE International
Power Modulator Symposium and 2008 High Voltage Workshop, Las Vegas, NV, pp. 33-36. * This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
O19-2: Optical Emission Diagnostics of the Plasma Channel in the Pulsed
Electrical Discharge in Gas Bubbles S. Gershman1, A. Belkind1, K. Becker2
1A. Belkind & Associates, LLC, North Plainfield, NJ, United States
2Polytechnic Institute of New York University, Brooklyn, NY, United States
Optical emission spectroscopy and fast time-resolved imaging are used to assess the plasma parameters in the plasma channel of a pulsed power electrical discharge in gas bubbles. Gas bubbles are produced at the tip of a needle electrode and submerged in water. The discharge in Ar, O2, and air bubbles is generated by applying 1s long, 8 – 20 kV rectangular voltage pulses to the needle electrode. Spectroscopic methods based on line intensity ratios and Boltzmann plots of line intensities of Ar, H, Ar+ and the examination of molecular emission bands from N2 and OH radicals provide evidence of both fast beam-like electrons and slow thermalized ones with temperatures of 0.6 – 0.8 eV. Spectroscopic study of rotational-vibrational bands of OH radical and N2 gives vibrational and rotational excitation temperatures of about 0.9 eV and 0.1 eV respectively. This investigation provides important experimental information about the characteristics of the plasma in the discharge channel. Accurate experimental information is important for practical applications of discharge in gas bubbles at atmospheric pressure as well as for theoretical understanding and modeling that cannot proceed without a thorough experimental base.
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O19-3: An in-Depth Investigation into the Effect of Oil Pressure on the Complete
Statistical Performance of a High Pressure, Flowing Oil Switch*
P. Norgard, R. D. Curry Center for Physical and Power Electronics,
University of Missouri-Columbia, Columbia, MO, United States
A high pressure, flowing oil dielectric switch was developed for high performance high voltage switching, and extensively evaluated by the University of Missouri-Columbia. The switch was designed to produce a continuous train of nanosecond rise, electrical impulses, with a peak output power ranging up to several gigawatts, and at repetition frequencies ranging up to several kilohertz. High pressure, flowing oil was proposed for the switching medium as a means of enabling rapid recovery of the insulating properties of the dielectric following electrical breakdown. The switch was developed for self-breakdown operation, with an anticipated lifetime of greater than 107 switching cycles. An experimental study of the statistical performance of the high pressure, flowing oil switch was conducted over a range of oil pressures from 0.5 – 10 MPa (72 – 1450 psig), oil flow rates from 10 – 40 Lpm (2.6 – 10.6 gpm), peak modulator charge voltages from 12.5 – 25.0 kV, and gap separations from 0.40 – 1.00 mm, utilizing self-breakdown at repetition frequency of 2 Hz. In this paper, we review the effects of operating the switch over the full range of oil pressures at constant modulator charge voltage, constant gap separation, and constant oil flow rate in a study of the complete statistical performance of the high pressure oil switch. The breakdown characteristics of the high pressure oil switch demonstrate remarkable properties, including a linear dependence relating the oil pressure to both the mean and maximum breakdown electric field strength, independence of the minimum break-down electric field strength on oil pressure, and a decidedly non-linear relationship between oil pressure and breakdown electric field strength standard deviation. *The program funding was supplied partially by UDRI under contract number RSC07011.
O19-4: Generation of Discharge Plasma in Water by High Repetition Rate Pulsed
Power Modulator K. Kouno1, T. Sakugawa1, K. Kawamoto1,
S. H. R. Hosseini1, S. Katsuki1, H. Akiyama1, Z. Li2
1Graduate School of Science and Technology, Kumamoto University , Kumamoto, Japan 2Electrical Engineering, Toyo University,
Kawagoe, Japan
Recently, all solid-state pulsed power generators, which are operated with high repetition rate, long lifetime and high reliability, have been developed to be used for industrial applications of plasmas, such as high repetition rate pulsed gas lasers, high energy density plasma (EUV sources) and pulsed ozonizer. However, researches on high repetition rate discharge plasma in water less than researches on gas discharge plasma. We have studied and developed high repetition rate compact pulsed power modulator for discharge plasma in water. This modulator consists of thyristor switch circuit and magnetic pulse compression (MPC) circuit. This modulator is able to generate an output voltage of about 25kV with voltage rise time of less than 200 ns. And repetition rate are 500 pulses per second (pps). We did the operation test and generate the streamer like discharge in the water with less than 350 pps. And we found that under water discharge plasma formation is change at high repetition rate of over 350 pps.
270
O19-5: VUV Emission from Dielectric Surface Flashover at Atmospheric
Pressure T. G. Rogers1, A. Neuber1, G. Laity1, K. Frank1,
J. Dickens1, T. Schramm2 1Center for Pulsed Power and Power Electronics, Texas Tech University, Lubbock, Texas, United
States 2Department of Physics, Am Hubland, D-97074
Wuerzburg, Germany Spectroscopic measurements in the vacuum ultraviolet (VUV) regime are difficult to make due to extremely large absorption of VUV radiation in most materials. This paper describes an experimental setup designed for studying the optical emission during pulsed surface flashover for the wavelength range between 115 nm to 300 nm at atmospheric pressures with a focus on the device used to excite the spark gap. The surface flashover of interest occurred on an MgF2 window (front side of window in air, backside in vacuum) directly flanged to a vacuum spectrograph VM 505 from Acton Research Corporation. The spectra were recorded with an Andor DH520 series ICCD camera in combination with a Nikon 105 mm lens and a sodium salicylate. Spectra were measured at atmospheric pressure with a flashover spark length of about 9 mm created by a pulser designed for a 500 ns, 50 kV output. The centerpiece of this pulser is the CCSTA14N40 thyristor by Solidtron / Silicon Power which features a rate of change current of maximum 30 kA/us and a hold-off voltage of up to 4 kV. A pulse transformer with Metglas® core was used to elevate the voltage to 50 kV with a rise time of 180 ns and a peak current of 500 A. The pulser was designed for a repetition rate of 10 Hz and is triggered by 100 us TTL pulses. Emission spectra were measured from 300 nm down to 130 nm. Besides spectral lines from gases such as nitrogen, magnesium ion lines were detected as well, indicating surface erosion of the MgF2 window. Discussed in this paper, along with the measured spectra and their relation to the physics of surface flashover at atmospheric pressure, will be the design of the pulser. * Work supported by the Air Force Office of Scientific Research
O19-6: Pulsed Breakdown Characterization of Advanced Liquid
Dielectrics for High-Power, High-Pressure, Rep-Rate Oil Switching*
C. Yeckel, R. D. Curry Center for Physical and Power Electronics,
University of Missouri-Columbia, Columbia, MO, United States
As more applications require high power and rep-rate capabilities, the University of Missouri-Columbia is investigating the design of liquid dielectric switches. In particular, the design and characterization of liquid dielectrics is critical to switch optimization. Previous improvements, such as tuning of the oil pressure and flow rate, have dramatically reduced the rep-rate self-break jitter. The magnitude of self-break jitter can be further minimized through optimization of the oil dielectric formula. Several advanced oils have been identified by a collaborating institution for characterization at MU as a pressurized dielectric switching media. The oils tested were Diala AX transformer oil, two 1-decene polyalphaolefins, two decence/dodecene polyalphaolefin mixtures, a silahydrocarbon, an ester, an alkylbenzene, and DC 200 silicone oil. Experiments on the pulsed voltage breakdown were performed to characterize the breakdown behavior of these dielectrics. A pulse generator, specifically designed for the characterization of oil dielectric strength, was implemented for this study. The pulse generator produced a voltage rate of 250-kV/µs across a 1.65-mm electrode gap. Thirty voltage pulses were applied to each of the nine oils at five oil pressures, totaling 150 breakdown measurements per oil. The oils were pressurized at 3.45, 5.17, 6.89, 8.62, and 10.34-MPa, respectfully. Before each test cycle, the oil was sparged with dry nitrogen to reduce the water content, and the switch electrodes were polished. The oil was filtered through a 0.45-µm filter between each of the 150 tests. A description of the pulse generator is provided, and the experimental procedure is discussed. Data for the nine dielectric oils are presented and analyzed, including the mean and standard deviation of the voltage breakdown data. *This program was funded by UDRI under contract number RSC07011.
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O19-7: Time Resolved Imaging of a Pulsed Plasma Discharge in Water
P. Ceccato, O. Guaitella, A. Rousseau LPP Ecole Polytechnique, Palaiseau, France
Plasma discharges in dielectric liquids are widely used in pulsed power applications such as switches and transmission lines. More recently plasma discharges inside water have been used as a source of chemical radicals (OH) for pollution control applications. Such filamentary discharges are able to non selectively oxidize any toxic organic molecules dissolved in the liquid into harmless components. However, the initiation and propagation mechanisms of a plasma discharge inside a dense media are still intensively discussed. It is not clear if there is a streamer-like mechanism or a "bubble mechanism". The main question for plasma discharge in liquids is to know if there are electron avalanches in the dense media or not. In the present study, time resolved imaging of the discharge is performed in a point to plane configuration with cm gap range. Marx generator and solid state switch was used with 20ns rise time and hundreds of µs pulse duration. A capacitive divider probe and a wide band current transformer probe were used for U-I measurements. Two iCCD and a streak camera have been used for time resolved imaging and were triggered on the electrical diagnostics. Several experimental parameters have been investigated: voltage amplitude, voltage pulse duration, voltage polarity, gap, liquid ionic conductivity, presence of gas injection, presence of a dielectric barrier, etc. A statistical study (laue plot) of the time delay of the discharge initiation was performed. Its experimental behaviour is consistent with a microbubble nucleation with local joule heating at the tip electrode. The propagation velocity was also measured as a function of those experimental parameters. Two different plasma modes have been observed in the positive polarity: a slow mode(10m/s) and a fast mode(30-35km/s). Only one slow mode has been observed at negative polarity (400-500m/s). In both polarities the slow modes are weakly luminous and consist of a heavily structured gas cavity. The discharge current is a succession of 20ns peaks of typically 1A amplitude. Transient bright spots can be observed at filaments tips. The fast positive mode has a more filamentary morphology with branching. The number of filaments is related to the discharge current. The emission intensity is uniform along the filament and the propagation is continuous without steps. The discharge stops to propagate when applied voltage reaches a threshold value or after some electric field screening at low ionic conductivity. Ultrafast reillumination of a previously extinguished filament can occur at low ionic
conductivity and lead to a step propagation. The propagation velocity of the fast mode has been found to be constant during the propagation whatever the experimental parameters, and in particular as a function of the Laplacian electric field and the water ionic conductivity. Measuring the propagation velocity gives an insight on the propagation mechanism. The fact that the measured propagation velocity remains constant indicates some limiting mechanism such as voltage drop inside the plasma filament or density lowering by local energy deposition at the plasma channel tip.
272
O19-8: Dynamic Arc Modeling of Pollution Flashover Process on HV
Insulators under AC Voltage M. K. Mohamed Ali
Mr. Mustafa Khalil Mohamed Ali, Cairo, Egypt
The aim of this contribution is to present a dynamic model allowing the prediction of the process of the AC arc development on ceramic insulators. The pollution flashover, observed on insulators used in high voltage transmission lines and substations, is one of the most important problems for power transmission. Dynamic models allow the prediction of discharge activity leading to the flashover of polluted insulators and taking into account the instantaneous changes in the arc parameters (voltage, current, length, resistance, speed, etc) and the model also taking into account the configuration of the insulator profile and the change in pollution resistance. A practical insulator geometries have been studied to demonstrate the model. The validity of the model was verified by comparing the computed results with the experimental results.
273
O20: Industrial, Commercial, & Medical Applications
Colonial
Thursday, July 2 9:15-11:15
O20-1: Near-Field Imaging of Tumor Tissue with Sub-Nanosecond Electrical Pulses
S. Xiao1, C. Baum2, K. H. Schoenbach1 1Old Dominion University, Frank Reidy Research
Center for Bioelectrics, Norfolk, VA, United States
2University of New Mexico, Department of Electrical and Computer Engineering,
Albuquerque, NM, United States
The dielectric properties, conductivity and permittivity, of biological tissue differ considerably depending on type of tissue. Electrical measurements can therefore provide additional information on tissues in addition to those obtained by existing modalities such as X-ray computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound. Even for the same tissue, a pathological change may result in major changes in dielectric properties, which could serve as a marker to discriminate between normal and pathological conditions. For example, breast tumors, one of the leading causes of woman’s death in the U.S., have an order of magnitude higher electrical conductivity and permittivity than normal tissue over a wide frequency range [1], and can therefore be differentiated from the normal tissue. Wideband, nonionizing, pulsed electromagnetic radiation in the near field region can be used to study the electrical property of biological tissues. The scattered signal contains information on the dielectric properties and the geometry of the target and allows its identification through an inverse scattering method. 3-D scanning allows us to obtain the dielectric profile of the tissue under observation and to detect any abnormality in a uniform background due to the dielectric contrast. Electromagnetic waves attenuate strongly in lossy media such as tissues. A high intensity signal is therefore required to compensate for the attenuation and to obtain a detectable signal. To radiate subnanosecond electric pulses with high field amplitude, we use impulse radiation antennas (IRAs). In this case the electromagnetic energy is focused in the near-field region by means of a prolate-spheroidal reflector. Previous analytical and numerical analysis [2,3,4] have shown that prolate spheroidal antennas emitting ultrawideband pulses with temporal width of approximately 100 ps allow us to focus high power electromagnetic wideband radiation in the near field region with a spatial resolution on the order of one centimeter in tissue. We present experimental results in this paper, including the antenna construction, the near-field
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characterization, and the transmitter-receiver configuration in the imaging system. Acknowledgement: This work has been supported by AFOSR and by Bioelectrics Inc., VA. [1] M. Lazebnik, D. Popovic, L. McCarteny, C. B. Watkins, M. J. Lindstrom, J. Harter, S. Sewall, T. Ogilvie, A. Magliocco, T. M. Breslin, W. Temple, D. Mew, J. H. Booske, M. Okoniewski, and S. Hagness, “A large scale study of the ultrawideband microwave dielectric properties of normal, benign and malignant breast tissues obtained from cancer surgeries,” Phys. Med. Biol. 52(2007), 6093-6115. [2] K. Hiragana, K. Fujimoto, T. Uchikura, S. Hirafuku, H. Naito, “Power Focusing Characteristics of Ellipsoidal Reflector,” IEEE trans. A.P., 32 (10), 1033-1039, 1984. [3] S. H. Kim, K. W. Chen and J. S. Yang, “Modal Analysis of Wake Fields and Its Application to Elliptical Pill-box Cavity with Finite Aperture,” J. Appl. Phys., 68 (10), p. 4942, 1990. [4] C. E. Baum, “Focal Waveform of a Prolate-spheroidal IRA”, 42 (6), Radio Science.
O20-2: Bioelectric Studies with Subnanosecond Pulsed Electric Fields
J. T. Camp1, X. Shu1, S. Beebe1, P. F. Blackmore2, K. H. Shoenbach1
1Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, United
States 2Eastern Virginia Medical School, Norfolk, VA,
United States
Nanosecond electrical pulses have been successfully used to treat melanoma tumors by using needle arrays as pulse delivery systems. Reducing the pulse duration of intense electric field pulses from nanoseconds into the subnanosecond range, and using a prolate-spheroidal reflector as part of a picosecond Impulse Radiating Antenna (IRA), allows us to focus the electromagnetic waves into biological tissue with reasonable spatial resolution [1]. In order to achieve a spatial resolution on the order of one centimeter, pulses with duration on the order of 100 picoseconds are required. Based on the nanosecond pulse generator [3], a pulse generator was developed which allows us to generate 150 picosecond-long pulses [4]. The voltage amplitude (in an improved version) reaches values of up to 120kV. Modeling results indicate that with this pulse generator as part of an IRI, electric fields on the order of 100 kV/cm can be generated in tissue close to the body surface. In order to explore the biological effects of these ultrashort, high electric fields, a coaxial exposure chamber has been designed which is integrated into the pulse delivery system in such a way that a uniform electric field (based on modeling using MAGIC) can be expected. The chamber is placed in a water bath, which allows us to vary the ambient temperature from room temperature (20 C) to a physiologically relevant range (37 C to 41C). Experiments where platelets were exposed to 150 picosecond long pulses with an electric field of 100 kV/cm indicate a pulse number dependent uptake of calcium. The experiments were performed at a temperature of 37 C. Raising the temperature is expected to increase calcium uptake and lead ultimately to the activation of platelets. Such activation, which was observed when platelets were exposed to nanosecond pulses [5], can be used to accelerate the healing of wounds non invasively using impulse radiating antennas. This work is being supported by AFOSR and by Bioelectrics, Inc. [1] Shu Xiao, Karl H. Schoenbach, and Carl E. Baum, “Time-Domain Focusing Radar for Medical Imaging,” Proc. URSI General Assembly, Session E, Chicago, IL, August 2008, in press. [2] Carey, W.J., and Mayes, J.R. (2003). “Marx Generator Design and Performance.” Proc. Modulator Conf 2003, p. 625; [3] Tammo Heeren,
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J. Thomas Camp, Juergen F. Kolb, Karl H. Schoenbach, Sunao Katsuki, and Hidenori Akiyama, “250 kV Subnanosecond Pulse Generator with Adjustable Pulsewidth,” IEEE Trans. Diel. Electr. Insul. 14, pp. 884-888 (2007). [4] J. Thomas Camp, Shu Xiao, and Karl H. Schoenbach, “Development of a High Voltage, 150 ps Pulse Generator for Biological Applications,” Conf. Rec. 2008 IEEE Intern. Power Modulator and High Voltage Conf., Las Vegas, NV, pp.338-341. [5] J. Zhang, P.F. Blackmore, B.Y. Hargrave, S. Xiao, S.J. Beebe, and K.H. Schoenbach, “The Characteristics of Nanosecond Pulsed Electrical Field Stimulation on Platelet Aggregation in Vitro,” Arch. Biochem. Biophys., vol. 471, pp. 240-248 (2008).
O20-3: Direct Versus Capacitive Coupling in Cell Electroporation Experiments
D. M. French1, R. M. Gilgenbach1, Y. Y. Lau1, M. D. Uhler2
1Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI, United
States 2Biological Chemistry, University of Michigan,
Ann Arbor, MI, United States Cell electroporation using fields radiated or broadcast from an antenna is very attractive for both clinical and research applications. Experiments were performed to establish the basics of coupling a radiated field capacitively to a sample of cells in order to determine if electroporation can occur. Experiments have been performed using sub-nanosecond rise time pulses. Cells immobilized in agarose gel were exposed to electric fields either by direct connection with electrodes or capacitive coupling. The differences between these two cases as determined from experiment and simulations will be discussed. The addition of bleomycin to the cell suspension leads to in an increase in the percentage of cells killed due to uptake being increased as a result of pores in the cells [1]. The chemotherapeutic enhancement effect of bleomycin under specified electroporation conditions was determined at various times after electroporation. In addition, the use of fluorescent dye binding to DNA allowed for estimation of immediate killing of treated cells. The results of experiments and simulations of conventional long pulse electroporation which show spatially resolved current density profiles and the associated cell killing will also be presented. 1. David W. Jordan, Michael D. Uhler, Ronald M. Gilgenbach, and Y. Y. Lau, Enhancement of cancer chemotherapy in vitro by intense ultrawideband electric field pulses, J. Appl. Phys. 99, 094701 (2006) Work supported by AFOSR
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O20-4: Thermal and Non-Thermal Effects of Intense Burst Sinusoidal Electric
Fields on HeLa Cells S. Katsuki1, K. Mitsutake2, N. Nomura2,
M. Hirakawa2, K. Abe2, i2, K. Morotom K. I. Yano1, H. Akiyama1, T. Shuto3, H. Kai3
1Bioelectrics Research Center, Kumamoto University, Kumamoto, Japan
2Graduate School of Science and Technology, Kumamoto University, Kumamoto, Japan 3Faculty of Medical and Pharmaceutical
Sciences, Kumamoto University, Kumamoto, Japan
In the last decade biological effects of nanosecond pulsed electric fields (nsPEF) have been intensively investigated by Schoenbachs and Verniers groups. They reported that nsPEFs give intracellular effects to biological targets and induce several unique reactions such as calcium burst, activation of caspase, nanoporation, etc. Also they applied nsPEFs to mice for the remediation of melanoma. Also the nsPEF as unique biological stimuli has a huge potential to be applied in agriculture and food processing industries as well as medical fields. We have used intense burst sinusoidal electric fields (IBSEF) in order to give a well-defined electric field in terms of frequency, field strength and duration. This is preferable to focus the electrical energy on a specific target and to understand how the electric field works on the target. This paper describes the possibility to induce apoptosis to HeLa cells (human cancer cells) by applying IBSEF. Phosphatidylserine (PS) translocation is monitored as a signal of apoptosis reaction. Cells in the early-to-mid phase of apoptotic process are detected by using the marking molecule annexin V-FITC for PS. Propidium iodide (PI), a fluorescent dye that is impermeable to plasma membrane, was used simultaneously to detect dead cells. We use a fluorescent microscope for morphological analysis of apoptotic cells and a flowcytometer for statistical analysis of thousands of cells. The frequency and the field strength of IBSEF were fixed in this experiment at 100 MHz and 200 kV/m, respectively. The frequency of 100 MHz is sufficiently large for the field to penetrate into HeLa cells. Here, we compare two IBSEF pulsing sequences, one is 50 shots of 200 s-long pulse with 2 s interval and the other is single 10 ms-long pulsing. The energies dissipated in the cell suspending media are the same, whereas the temperature rises during the pulsing are different between two cases. The pulsing sequence with 200 s-long pulses is a non-thermal effect because the temperature rise during the pulsing is only 0.6˚C, which decays within seconds. On the other hand, the single 10 ms-long pulsing, which raises the temperature by approximately
30˚C, gives both non-thermal and transient thermal effects to HeLa cells. The cells subjected to the IBSEFs were analyzed at two different times, 2 and 6 hours after the pulsing. The PS translocation was detected in both cases and degrees of the translocation were the same level 2 hours after the pulsing. The number of apoptotic cells was increased 4 hours later (6 hours after the pulsing) in both cases. More apoptotic cells were detected in the case of single 10 ms-long pulsing. Our experiment shows that non-thermal effects of the intracellular intense electric fields are capable of inducing apoptosis to HeLa cells. Also the transient thermal effect is considered to enhance the biological stress leading to apoptosis.
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O20-5: Tumor Treatment with Nanosecond Pulsed Electric Fields
J. F. Kolb, X. Chen, J. Zhuang, W. Ren, S. Beebe, K. H. Schoenbach
Frank Reidy Research Center for Bioelectrics, Old Dominion University, VA, United States
Nanosecond Pulsed Electric Fields have demonstrated remarkable potential as tumor therapy. The application of 300-ns pulses with amplitudes of 40-50 kV/cm on melanomas, grown in mice, sent the tumors into complete remission. It is believed that the primary process that kills the tumor cells is the induction of apoptosis. Electrical models predict that for the application of shorter pulses, higher field strengths are required to trigger this process. By increasing field strength, the field eventually exceeds the dielectric strength of the tissue. As a consequence corona discharges can be observed, especially in the vicinity of small diameter needle electrodes. However, the non-thermal plasma could likely assist the tumor therapy by generating reactive oxidative species. We have investigated the regression of tumors that were treated with a coaxial electrode configuration comprised of a 0.4 mm needle electrode in the center of a solid ring electrode of 4 mm radius. With respect to the grounded ring-electrode, a 30 ns/27-kV high voltage pulse of either positive or negative polarity can be applied to the center electrode. With positive bias, strong corona discharges can be observed along the needle, while for the opposite polarity these are either negligible or do not occur. Tumor regression was compared for both conditions and with results for a 5-needle array of similar dimensions. Preliminary data could not determine any significant immediate advantages of either configuration. A long term study is underway.
O20-6: Low Energy Nanosecond Pulsed Plasma Disinfection Needle
C. Jiang1, M. T. Chen1, C. Schaudinn2, A. Gorur2, P. P. Sedghizadeh2, J. W. Costerton2,
P. T. Vernier1, M. A. Gundersen1 1Department of EE-Electrophysics, University of
Southern California, Los Angeles, CA, United States
2Center for Biofilms, School of Dentistry, University of Southern California, Los Angeles,
CA, United States
A 2-3 cm long, 4 kV electric pulses, when a flow of premixed He/(1%)O2 mixture exits the device nozzle at 1 L/min. Similar plasma has been applied for endodontic biofilms disinfection. Effective biofilm removal for a depth of 1 mm in a root canal was observed. [1] The temperature of nutrient media directly under plasma exposure was measured to be less than 30 oC for 5 min. This room temperature plasma can also be applied for wound disinfection. Effective inactivation of typical wound bacteria, /Staphylococcus aureus/, /Pseudomonas aeruginosa/, and /Staphylococcus epidermidis/ on nutrient agar plates was observed after plasma treatment for 5 minutes and incubation for 24 hours. The bacteria-free (>99%) voids on agar plate created by plasma exposure are larger than 3 cm in diameter for an initial bacterial concentration of >10^5 CFUs/cm^2, which implies that the nanosecond pulsed plasma needle can be an efficient, effective, and safe wound disinfection tool. This work is partly supported the Air Force Office of Scientific Research and a Los Angeles Basin Clinical and Translational Science Institute Pilot and Feasibility Grant. [1] C. Jiang, M.T. Chen, P.A. Gorur, C. Schaudinn, D.E. Jaramillo, J.W. Costerton, P.P. Sedghizadeh, P.T. Vernier, M.A. Gundersen, "Endodontic biofilm disinfection by a cold atmospheric-pressure plasma," IEEE Trans. Plasma Science, 2009, in press.
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O20-7: Decontamination of Wastewater by Pulsed Electric Field Treatment: a
Critical Evaluation C. A. Gusbeth1, W. Frey1, G. Mller1, T. Schwartz2
1IHM, Forschungszentrum Karlsruhe GmbH, Karlsruhe, Germany
2ITC-CPV, Forschungszentrum Karlsruhe GmbH, Karlsruhe, Germany
Conventional methods of bacterial decontamination of wastewater, e.g. chlorination or ozonization can produce toxic by-products, originated from organic substances. UV-disinfection is not effective in turbid water. Thus, the pulsed electric field (PEF) treatment of wastewater as a non-chemical disinfection method seems to be a suitable alternative method for reducing this bacterial load. This was demonstrated for the decontamination of hospital wastewater loaded with pathogenic and increasingly antibiotic resistant bacteria. Besides the inactivation efficiency, the economic efficiency is an important aspect in the case of treating wastewater from municipal purification plants. The additional costs for decontamination of wastewater should not exceed 10 % of the total cost for purification (2.14 /m3). In this study we investigated the efficiency of the PEF method for wastewater decontamination and the electro-sensitivity of wastewater bacteria to PEF treatment. For this purpose wastewater was sampled at the effluent of 4 different wastewater purification plants and at the wastewater outlet of two hospitals. The wastewater properties differed according to the time of sampling and weather. To investigate the electro-sensitivity of wastewater bacteria, filtered wastewater samples were inoculated with representative wastewater bacteria, e.g. E. faecalis, E. faecium, E. casseliflavus and exposed to different PEF treatments. A transmission line pulse generator was used for the PEF treatments. It delivers square pulses with a voltage amplitude between 8 and 20 kV. The pulse duration ranges from 0.6 to 2 s. For wastewater samples with a high concentration of tolerant bacteria (Gram-positive bacteria) the inactivation efficiency was low. Using ChromoCult enterococcus-agar it could be shown that the bacterial population shifted after the PEF treatment to a bacterial mixture with an increased concentration of electro-tolerant bacteria (Enterococcus). Furthermore, the electro-tolerance of the bacteria to PEF treatment differs within the same species, as found for E. faecium. Generally, the bacterial reduction depends on the sampling point (purification plant) and on the electrically dissipated treatment energy. In order to achieve a satisfactory bacterial inactivation (3.5 logs) a specific electric treatment energy between 120 J/ml and 240 J/ml is necessary. The high energy consumption is the
limiting factor for an industrial application of this method. Combined treatments of wastewater with PEF and heat (50-60 C) could reduce the costs for bacterial contamination considerably.
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O20-8: Multi-Electrode Electrohydraulic Discharge for Sterilization and
Disinfection Y. Huang, H. Yan, S. Li, K. Yan
Department of Environmental Science, Zhejiang University, Hangzhou, China
Electrohydraulic discharge (EHD) can generate localized plasma, which emitting high intensity ultraviolet, and generating shock wave and hydroxyl radical. It is a multiple mode-of-action approach of sterilization and disinfection. Based on a homemade experimental setup, including all solid-switch capacitive pulsed power source and multi-electrode EHD reactor, we experimently investigate the mechanism of EHD for Chlorella killing. Typical energy range of the pulse power source is 5-500J with a repetition rate of 0.1Hz-1Hz. Mono-current pulse wave is applied on the EHD reactor. We also design a multi-electrode configuration to increase the Chlorella killing effeciency of over 99%. Besides, a monochromator combined with PMT and a high speed camera system are used to detect the emission spectrum and plasma bubble growth proccess, respectively. After discharging, the concentration of chlorophyll measured by UV-visible spectrophotometer rises, which is caused by the broken up of Chlorella.
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03P: Industrial, Commercial, & Medical Applications and Explosive and Compact Pulsed Power
East/State
Thursday, July 2 11:15-12:30
03P-1: Energy Deposition Assessment and Electromagnetic Evaluation of
Electroexplosive Devices in a Pulsed Power Environment
J. Parson, J. Dickens, J. Walter, A. Neuber Electrical and Computer Engineering, Texas Tech University, Lubbock, TX, United States
This paper assesses critical activation limits of electroexplosive devices (EED), such as blasting caps, which are commonly used in pulsed power environments. These devices, EEDs, can be very sensitive to low levels of energy (7-8 mJ) which make them dangerous to unintended radiation produced by compact pulsed generators. Safe operation and use of these devices are very important when in use near devices that produce pulsed electromagnetic interference. The scope of this paper is to provide an evaluation of activation characteristics for EEDs that include energy sensitivity tests, thermodynamic modeling, and electromagnetic compatibility from pulsed electromagnetic interference. Two methods of energy deposition into the bridgewire of the EED are used in the sensitivity tests. These methods include single and periodic pulses of current that represent the adiabatic and non-adiabatic heating of the bridgewire. The heating of the brigewire is modeled by a solution to the heat equation using COMSOL™ with physical geometries of the EED provided by the manufacturer.
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03P-2: Experiments on a 1-MA Linear Transformer Driver
R. M. Gilgenbach1, M. R. Gomez1, J. Zier1, D. M. French1, Y. Y. Lau1, M. G. Mazarakis2, M. E. Cuneo2, B. V. Oliver2, T. A. Mehlhorn2
1Nuclear Eng. & Rad. Sciences, University of Michigan, Ann Arbor, MI, United States
2Sandia National Labs, Albuquerque, NM, United States
A 1-MA Linear Transformer Driver (LTD) has been reconstructed and tested at the University of Michigan. This is the first 1-MA LTD to be operated in the USA. The LTD was initially designed, constructed and tested at the Institute of High Current Electronics (Tomsk, Russia) in collaboration with Sandia National Labs and UM. This compact LTD (3.06 m diameter by 0.22 m thick), utilizes 80 capacitors charged up to +-100 kV with 40 multi-gap switches arranged into 40 bricks. Each brick generates 25 kA. The generated LTD output pulse is 1 MA, 100 kV with a 90 ns risetime into a matched, low inductance load. A magnetically-insulated transmission line (MITL) has been designed and constructed to transmit the 0.1 TW pulsed power to a central load. Experimental results will be presented for tests of the full LTD and MITL. Initial experiments were performed with 10 low inductance KBr resistors inside the LTD cavity, which was filled with SF6. MITL tests on the LTD are conducted in vacuum with 20 ceramic resistors. Plasma physics experiments under construction and testing on this 1-MA LTD include: 1) Posthole convolute experiments that will characterize the effects of plasma closure on the performance of vacuum convolute current adders, and 2) Magneto Rayleigh-Taylor instability experiments that will utilize thin, planar metal foil loads to study instability generation, seeding and mitigation. Preliminary experimental results will be reported and compared with circuit models and MAGIC code simulations. *This research was supported by U. S. DoE through Sandia National Laboratories award document numbers 240985, 768225, 790791 and 805234 to the University of Michigan. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energys National Nuclear Security Administration under Contract DE-AC04-94AL85000. MRG was supported by the Stockpile Stewardship Graduate Fellowship awarded by the KRELL Institute in conjunction with the DoE/NNSA. JZ received a NPSC Fellowship funded by Sandia.
03P-3: A Compact 5kV Battery-Capacitor Seed Source with Rapid Capacitor
Charger S. L. Holt1, J. Dickens1, J. L. McKinney1,
M. Kristiansen1, L. Altgilbers2 1Center for Pulsed Power and Power Electonics,
Texas Tech University, Lubbock, TX, United States
2Space and Missile Defense Command, United States Army, Huntsville, AL, United States
Many pulsed power applications have demanding system requirements. Power systems for these applications are expected to provide high energy, high pulsed power and long standby times without recharge all in a very compact package. Batteries provide high energy densities but cannot provide the power density required by some high power systems. The inverse is true for capacitors, they provide high power densities but at low energy densities. Batteries are also better suited for systems with long standby times as battery self discharge rates are typically much better than capacitor discharge rates through leakage current. When selecting a prime power source for compact pulsed power systems a hybrid system often provides the optimal solution, utilizing a battery for prime energy storage during standby and a capacitor for intermediate energy storage before and between operations. This system takes advantage of the best characteristics of both sources to fulfill the system requirements. The design and testing of such a compact system is discussed. The system utilizes a solid-state converter to charge a 50 F polypropylene capacitor to 5 kV in under 500 ms from lithium-ion polymer (LiPo) batteries. Battery selection and testing will also be covered. The battery and charger assembly occupies 900 ml while the capacitor occupies an additional 1 L. The charger performance will be examined in single use, low rep-rate, and high rep-rate burst modes.
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03P-4: Limits and Failure Modes in High Voltage Vector Inversion Generators
Z. S. Roberts, Z. D. Shotts, M. F. Rose Radiance Technologies, Huntsville, Alabama,
United States
In our laboratory, we have been researching and developing Vector Inversion Generators, VIG), for several years and have been reported extensively in the IEEE Pulsed Power Conferences (1,2,3). VIGs consist of two parallel plate transmission lines, wound on a mandrel and sharing a common conductor. They are a compact electrostatic energy storage device that can convert the stored energy into a traveling RF wave in a one component-one step process. In that regard, they are unique. In recent years, there have been a number of advances in materials technology and construction techniques that have led to substantial improvements in efficiency, life, and ease of manufacture. In our laboratory, we have constructed VIGs that can function at voltages up to 1 MV with limited lifetime in a coke can size package. Similarly, we routinely operate VIG devices at high repetition rates for millions of charge/discharge cycles. In the course of developing these devices, we have formulated a series of design equations and methodology that allow us to determine the parameter range that must be achieved for specified performance. In this paper, we will discuss the basic design equations that allow determination of the VIG erection time, the amount of energy stored in the unit, the amount of energy available at the output of the device and the restrictions on the value of the load impedance necessary for efficient energy transfer. We will describe a method for determining the maximum current, I, and dI/dt that the two switches, low voltage input and high voltage output switch to the load, will see and the constraints imposed on the unit by these parameters. While the above parameters can be uniquely specified, great care must be taken in materials selection, precision winding technique, and insulation scheme to realize a unit that performs to its full potential. Usually, the actual performance of the devices constructed by this methodology, are within a few percent of the predictions for modest input voltage and for voltages less than 500 kV. We will describe the limits on VIG technology as imposed by fundamental processes. For example, there appear to be materials imposed limits both to the charge voltage and the erected voltage that a unit can achieve. Each of these failure mechanisms limits the life of a particular device and forces a trade-off between maximum operating voltages and numbers of charge-discharge cycles. We will discuss corona production within the VIG, its effects on the output voltage, and techniques to
mitigate its effects. The techniques include precision foils, oils and potting compounds, and geometry of the individual windings on the VIG.
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03P-5: High Voltage Solid State Switched Vector Inversion Generator for HPM
Applications Z. D. Shotts, M. F. Rose
Radiance Technologies, Huntsville, Alabama, United States
For most repetitive pulsed power applications, a highly reliable power conditioning system is essential. Its function is to take the prime power source and format it to the input parameters of the load that usually needs both high voltage and current. The Vector Inversion Generator, VIG, is a device that takes electrostatically stored energy and converts it into a high-power, fast-rising electromagnetic pulse in essentially a one-component, one-step process. For many applications, VIG technology can effectively eliminate the need for multi-switching schemes and discrete capacitive storage elements. A VIG consists of two parallel plate transmission lines, sharing a common conductor that has been wound on a mandrel. These units can be made highly efficient and are capable of developing high transient voltages in a time that is determined by the two way transit time for an electromagnetic wave to propagate up the active line. Heretofore, the active line in a VIG device was switched using spark gaps because of the extremely high dI/dt and large values of current, I. Spark gap switches have limited life due to electrode erosion, are difficult to trigger with precision, and have limited pulse repetition rate. Further, spark switches are usually pressurized to increase operating voltage. If fast impedance collapse is needed, the gas used to pressurize the gap is usually hydrogen, which poses safety hazards and is difficult to keep from leaking from the system. By contrast, solid state switches have none of the undesirable characteristics associated with spark switches and gas plumbing but are limited in dI/dt, I and standoff voltage. We reported on our initial development of a solid state switched VIG in the 2007 Pulsed Power Conference [1] using a switch that was capable of 4.7 kV hold off voltage, peak current of 14 kA, and peak dI/dt of 30 kA/s. In this paper, we will describe the results of our efforts to produce a solid state switched, VIG capable of higher current and higher dI/dt for applications at high repetition rate and at modest energies. We will present VIG design methodology that determines the maximum value of both I and dI/dt that a switch will see as a function of line length and line impedance. Using these values as a guide, and switch parameters of maximum voltage of 4 kV, max current of 58 kA, and dI/dt of approximately 100 kA/s, we tested the switch in incremental steps to VIG output voltages of over 100 kV with no failures after approximately 5 million charge/discharge cycles. The test data will
be presented and analyzed in terms of limits on solid state switching for high repetition rate applications.
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03P-6: A Compact Nested High Voltage Generator for Medium Pulse Duration
Applications J. A. Gilbrech, R. J. Adler, F. K. Childers,
M. Hope, E. Koschmann Applied Energetics, Tucson, AZ, United States
The “Nested High Voltage Generator” (NHVG) topology is an effective way of distributing high DC voltages. It has been applied to a variety of technical problems including semiconductor ion implantation, X-ray security, and electron beam irradiation. We have built a unit for pulsed power applications including such applications as pulsed X-ray generation, pulsed plastics’ processing, medium power microwaves, and pulsed ion beam annealing. This unit is designed to produce 250 kV and up to 5 amperes for pulses of up to several milliseconds. Previous pulsed versions of the NHVG used “hard tube” switching but this unit uses series resonant solid state drive. Repetition rates will vary for this machine from 1 pps to 1 kHz depending on the applied pulse format. We will report on performance and also on prospects for propagating pulsed beams through the accelerator column.
03P-7: High-Power Compact Capacitor Charger
M. Giesselmann, T. T. Vollmer Pulsed Power & Pwr Elect., Texas Tech University, Lubbock, Tx, United States
We are reporting on a new design for a compact high power Capacitor charger with a power output that far exceeds the peak power of previously reported designs [1]. For this purpose we are evaluating parallel modular designs with separate inverters, transformers, & rectifiers and compare them with designs with a larger module size. For larger power implementations with a single inverter, transformer, & rectifier, the main challenge is the design of the inverter using parallel connected IGBT transistors and their current sharing. In addition the high-frequency impedance of the transformer may require litz wire windings [2]. We are planning to use current mode control for the inner current loop with a cascaded outer voltage loop. New variations of current mode control that operate on the principle of average current mode control rather than peak current mode control [1] are being assessed. [1] Giesselmann, Michael; Vollmer, Travis; Lara, Matt; Mayes, Jon, “Compact HV-Capacitor Charger”, Proceedings of the 2008 IEEE International Power Modulator Conference, Las Vegas, Nevada, May 27-31, 2008, Page(s):238 – 241. [2] Ryan C. Edwards and Michael G. Giesselmann, Characterization of a High Power Nanocrystalline Transformer, Proceedings of the 2007 IEEE Pulsed Power & Plasma Science Conference, Albuquerque, NM, June 17-22, 2007.
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03P-8: Compact Solid State Variable Amplitude High Repetition Rate Pulse
Generator S. J. Pendleton1, D. Singleton2, A. Kuthi2,
M. A. Gundersen1, 2 1Physics, University of Southern California, Los
Angeles, CA, United States 2Electrical Engineering - Electrophysics,
University of Southern California, Los Angeles, CA, United States
Presented is a solid state high repetition rate pulse generator with adjustable output amplitude, together with a resonant LC charger. This pulse generator was designed for transient plasma production for ignition and acoustic noise reduction applications. The design of the pulse-forming network makes use of commercially available insulated gate bipolar transistors (IGBT) switching a capacitor bank into a METGLAS transformer together with a Fitch voltage doubling circuit. The capacitor bank is charged to 1kV by a resonant LC charger, also switched by a commercial IGBT. The output of the pulse generator is controlled by the gate voltage of the IGBTs. Pulses with a width of 40ns can be generated with repetition rates up to 10kHz. The amplitude can be controlled from 9kV to 35kV into a 500ohm load.
03P-9: A 15 kA Linear Transformer Driver*
D. Matia, M. Giesselmann, A. Neuber, M. Kristiansen
Center for Pulsed Power and Power Electronics Department of Electrical and Computer
Engineering, Texas Tech University, Lubbock, TX, United States
The design of a 15kA linear transformer driver (LTD) is presented. The specific goal of this LTD was improved energy density over the 500 J compact Marx generator previously designed and built at Texas Tech’s Pulsed Power lab. The design of individual 50 joule stages charged to 30kV is discussed. For successful operation of the LTD multiple spark gaps have to be fired with low jitter. Possible approaches as well as the final implemented design of a low jitter triggering circuit will be presented as well. *Subject to approval for public release.
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03P-10: Design and Performance of an Ultra-Compact 1.8 kJ, 600 kV Pulsed
Power System C. Nunnally, J. R. Mayes, C. W. Hatfield, J.
Dowden Applied Physical Electronics LC, Austin, TX,
United States
A new, high-energy-density Marx generator has been developed for High Power Microwave (HPM) applications. A modular close-packing geometry combined with mica-film capacitor technology results in a 1.8 kJ energy storage capacity in a 20 in. x 45 in. cylindrical vessel. The generator has been shown to deliver 6 GW to a 30 Ohm load with a peak pulse voltage of 300 kV. The compact topology accomplishes a high energy per pulse, but also facilitates the lowest possible inductance of the system which is characterized by a 90 ns voltage risetime when discharged into a matched resistive load. The system includes an EMI hardened power electronics suite which includes a solid state trigger generator, compact HVPS, and a digital pressure regulator. The system requires only pressurized dry air for insulation, operates on an internal prime-power battery pack and operates via a fiber-optic remote control for ease of implementation on remote platforms. The system design and pulse characteristics for a resistive load are presented in this paper.
03P-11: Development of a Sequentially Switched Marx Generator for HPM Loads
J. R. Mayes, C. W. Hatfield Applied Physical Electronics, L.C., Austin, TX,
United States
Relativistic Magentrons prefer trapezoidal-shaped, high voltage pulses, as opposed to the double exponential waveshape characteristic of a Marx generator. Traditional approaches use intermediate Pulse Forming Lines (PFNs) or stacked Blumleins to create the desired pulse shape. Marx generator-driven PFNs are unacceptable, due to their size and additional overhead. Stacked Blumleins are very difficult to switch, when a large number of lines are required, which results in small line impedances. Applied Physical Electronics L.C. is developing a novel Marx generator topology that results in a rectangular waveshape, without additional pulse conditioning hardware. The topology is based on a multi-generator design. Each generator is sequentially switched to the common load, so as to simulate a rectangular waveshape. In essence, the desired rectangular pulse shape is built temporally, and the capacitance of the load can be designed to reduce the ripple in the load waveform. Each generator can be uniquely charged and triggered, resulting in a programmable, high voltage waveform generator. The generator is described for its geometry. Simulation and experimental results are provided.
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03P-12: A New, Compact Pulsed Power System Based on Surge Arrestor
Technology M. C. Clark
Collins Clark Technologies Inc., Albuquerque, New Mexico, United States
The conventional, repetitive pulsed power system incorporates a pulsed forming network at high impedance or a liquid dielectric transmission line at low impedance to produce the desired waveform. These systems are inherently complex and bulky. Explosive pulsed power is low impedance, simple and compact but is limited to specialized, single shot applications. In addition, a nonlinear element (typically a fuse) is required to condition the wave shape and transfer power to the load. Here, we describe an alternate approach to compact pulsed power which combines the advantages of both laboratory and explosive pulsed power in a simple system based on commercial surge arrestor technology. The surge arrestor (typically a Metal Oxide Varistor or MOV) was invented in the 1970’s by General Electric Corporation and is today used whenever electronic devices must be protected against power line surges. Surge arrestors are found in applications ranging from the spike protectors in household power strips, to large arrays capable of protecting entire power plants during megajoule lightning strikes. Connected across a power line, the MOV presents a very high impedance to the circuit until a specific threshold voltage is exceeded at which point it rapidly begins conducting (<50 nanoseconds) with characteristics of a forward biased diode (I~V^50). In the present concept, the MOV is inserted across the output of a conventional Marx generator and separated from the load by a triggered transfer switch. Upon erection, the Marx begins discharging into the MOV array which clamps the voltage at its characteristic value. At a predetermined time in this discharge, the transfer switch is closed, connecting the output into the load. Power is rapidly transferred to the load while the MOV elements now appear in parallel, controlling the load voltage. Using this technique, we have developed a line of commercial, compact pulsed power systems ranging from a 200 kilovolt, 5 microsecond, 1000 Ohm all solid state cathode driver to a 500 kilovolt, 30 ohm, 200 nanosecond, repetitive pulsed, High Power Microwave tube driver. In addition to the theory of operation, the performance characteristics of these devices will be presented. Finally we will discuss progress toward a 500 kilovolt, 10 ohm, 500 nanosecond repetitive pulsed system.
03P-13: Compact, DC-Powered 100Hz, 600kV Pulsed Power Source
M. B. Lara, J. R. Mayes, C. Nunnally, T. A. Holt Applied Physical Electronics, Austin, TX, United
States
A DC-powered, compact source capable of delivering upwards of 600 kV, 100 J/pulse at 100 Hz, is realized with a 10 kJ/s rapid capacitor charger driving a 16 stage Marx generator. The Marx generator and capacitor charger are fitted into a cylindrical package with approximate dimensions of 12”X60” and are powered from a 300VDC bus. The unit is controlled remotely via a fiber-optically isolated micro-controller which provides the gate drive signals and user interface for the rapid capacitor charger. Performance data for the Marx generator and the capacitor charger is presented in this paper.
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03P-14: Nanosecond FID Pulse Generator with Amplitude of 10 kV and PRF of 3.3
MHz V. M. Efanov, M. V. Efanov, A. V. Kriklenko,
N. K. Savastianov FID GmbH, Burbach, Germany
An all-solid-state pulse generator with very clean waveforms, based on FID technology, has been developed. The new pulser delivers output voltage of 10 kV into 50 Ohm in a rectangular voltage pulse with duration of 2-5 ns, rise time of 0.5-0.6 ns, and fall time of 2-3 ns. Pulse repetition rate is up to 3,3 MHz in bursts of 10-100 microseconds. The burst repetition rate can be up to several tens of kilohertz. The most important feature of the new design is the almost complete absence of pre- and after-pulses, measured at less than 0.2% of full amplitude of 10 kV. The pulser is a compact 480x400x120 mm, with internal forced-air cooling, and takes universal input power of 100-240VAC, 50-60Hz.
03P-15: Disk Magneto-Cumulative Energy Sources for X-Ray Complex EMIR
V. A. Demidov, A. S. Boriskin, S. A. Kazakov, A. A. Agapov, Y. V. Vlasov, R. M. Garipov,
S. N. Golosov, N. P. Kazakova, S. V. Kutumov, Y. N. Lashmanov, A. N. Moiseenko,
L. N. Plyashkevich, S. E. Pavlov, A. P. Romanov, A. S. Sevastyanov, O. M. Tatsenko,
A. V. Filippov, E. V. Shapovalov, E. I. Schetnikov, V. A. Yanenko
Scientific and Technical Center of Physics, Russian Federal Nuclear Center - VNIIEF, Sarov,
Nizhny Novgorod Region, Russian Federation
The first test of a disk magneto-cumulative generator (DMCG) with a high-explosive change of 480 mm diameter is carried out. The generator is a two-fold enlarged model of the earlier tested generator DMCG-240. It is intended for application in the EMIR complex for generation of soft x-ray radiation pulses at fast compression of multi-wire liners. The DMCG-480 generator consists of five disk elements. A current of ~90 MA with a characteristic rise time of ~6.5 µs was obtained in a generator load of ~7 nH inductance at an initial current of ~8 MA. A comparison of calculated and experimental results is presented in the paper. The five-element DMCG-480 was tested in combination with the explosive current opening switch with a ribbed barrier of 290 mm diameter. Rupture of a copper foil of 0.3 mm thickness was carried out at linear current density of ~0.17 MA/cm. A characteristic current rise time in a load is less than 1 µs.
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03P-16: Design of a Compact Power Conditioning Unit for Use with an
Explosively Driven High Power Microwave System
J. Korn1, A. Young1, C. Davis1, A. Neuber1, M. Kristiansen1, L. Altgilbers2
1The Center for Pulsed Power and Power Electronics, Texas Tech University, Lubbock, TX,
United States 2SMDC, U.S. Army, Huntsville, AL, United States
The generation of high power microwaves using explosively driven pulsed power is of particular interest to the defense community. The extremely high energy density of explosives provides the opportunity to design pulsed power systems which occupy significantly less volume, yet provide the same output power, as traditional methods of HPM production. An HPM system design has been established which uses a Flux Compression Generator (FCG) to drive a virtual cathode oscillator (vircator). The impedance mismatch between the FCG and vircator necessitates the use of an intermediate Power Conditioning Unit (PCU), which is composed of an energy storage inductor, an electro-explosive opening switch (fuse) and a self-break peaking gap. Dimensional constraints placed on the HPM system require that the PCU fit inside a cylinder with 15 cm diameter and take up a minimal amount of space. Operation of the PCU also dictates that it will need to accommodate currents in the tens of kilo-amperes and voltages in the hundreds of kilo-volts without electrical breakdown or failure. The design of the compact PCU is presented, which will detail the operation of each individual component, as well as the unit as a whole, and show the engineering involved which enabled the entire unit to fit in a volume of less than 11 liters while meeting the requirements stated above. Viewgraphs and waveforms will demonstrate the performance of the PCU when driven by an FCG and connected to a 20 ohm water resistor load, where currents greater than 40 kA were transformed into voltage pulses larger than 160 kV, resulting in powers dissipated in the resistive load exceeding 1.25 GW.
03P-17: Power Conditioning Opimization for a Flux Compression Generator Using
a Non-Explosive Testing System C. Davis, A. Young, A. Neuber, J. Dickens,
M. Kristiansen Center for Pulsed Power and Power Electronics,
Texas Tech University, Lubbock, TX, United States
This paper discusses a pulsed power device used to imitate output waveforms of a Flux Compression Generator (FCG) driving a High Power Microwave (HPM) source. This non-explosive system optimizes the power conditioning components of a HPM source while reducing the time and resources inherent to explosively driven FCG schemes. An energy storage inductor, fuse opening switch, and a peaking gap make up the power conditioning system. This system couples large voltage pulses (several 100 kV), suited for HPM sources, to the load by disrupting the energy storage inductor current of ~ 30 to 40 kA. Different arrangements of the power conditioning system and the load were explored to achieve optimal load voltage levels. Properly combining physical fuse compactness with the minimal fuse conductor length reduces energy loss and restrike during the vaporization process of the fuse. Therefore, various geometric fuse arrangements were examined to achieve nearly a 50% reduction in the physical fuse length at constant wire length with little to no performance loss. This paper will show that an optimal conductor length was found by varying the calculated fuse wire base length by 5, 10, and 20%, and that a 7% increase in energy transfer from the energy storage inductor to the load was observed by improving fuse wire contacts at the fuse terminals. Results from comparing various fuse geometries and fuse volumes as well as the relationship between voltage breakdown of the peaking gap and the voltage delivered to the load will be discussed.
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03P-18: An Innovative and Non-Invasive Technology for Food Processing
B. M. Novac, P. Sarkar, I. R. Smith, C. Greenwood
Electronic and Electrical Engineering, Loughborough University, Loughborough,
Leicestershire, United Kingdom
Pulsed electric field (PEF) processing is a mature technology already in use in the industrial food processing of, for example, fruit juice. It is however restricted to liquid (pumpable) food and involves metal electrodes in direct contact with the foodstuff – i.e. it is inherently an ‘invasive’ technology. In the last twelve months, Loughborough University has undertaken an experimental programme to demonstrate a new and ‘non-invasive’ technology that uses an antenna coupled to a fast high-voltage pulse generator to produce an intense pulsed electric field. The machine that has been built and successfully tested uses a Tesla-transformer-based pulse forming line generator coupled to a Valentine antenna to produce electric fields in excess of 250 kV/cm. The technology developed offers considerable promise for any type of food, including solid foods such as meat. Apart from the much greater volume available for processing, and other more or less obvious advantages, the new technique is also highly energy efficient as, unlike the existing invasive approach, it does not drive a current through the food being processed. The paper will present details of the experimental equipment and measurements of the electric field produced. Some of the major implications the technique may offer for the future of PEF food processing will be discussed.
03P-19: Current Pulse Effects on Damage Experiments in a Cylindrical Geometry
A. M. Kaul Applied Physics Division, Los Alamos National
Laboratory, Los Alamos, NM, United States Using a cylindrical configuration to study spallation damage allows for a natural recollection of the damaged material under proper driving conditions. In addition, the damaged material is able to come to a complete stop without the application of further forces. Specific areas of research include the damage initiation regime in convergent geometry, behavior of material recollected after damage, and effects of convergent geometry on the material response. These experiments challenge existing computational material models and databases and provide motivation to improve these models and increase the predictive capabilities of codes, as numerical modeling of such experiments requires the consideration of the effect of convergence and two-dimensional strains and shear stresses on the spallation profile of a material. A series of joint experiments between LANL and VNIIEF use a VNIIEF-designed helical generator to provide currents with peak values of 5 – 10 MA for driving a LANL-designed cylindrical spallation experimental load. Thus far, experiments have provided data about failure initiation of a well-characterized material (aluminum) in a cylindrical geometry, behavior of material recollected after damage from pressures in the damage initiation regime, and behavior of material recollected after complete failure (May 2009). In addition to post-shot collection of the damaged target material for subsequent metallographic analysis, dynamic in-situ experimental diagnostics include velocimetry and transverse radial radiography. This presentation will focus on the effects of tailoring the driving current pulse to obtain the desired data.
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03P-20: Pulsed Electric Field Effects on the Germination Rate of Sicklepod and
Yellow Nutsedge Seeds R. Bokka, S. Li, H. Kirkici
Electrical Engineering, Auburn University, Auburn, AL, United States
Pulsed electric field to treat seeds is an alternate method to the chemical treatment to control the weeds in the field. In this study SICKLEPOD and YELLOW NUTSEDGE seeds were subjected to DC and pulsed electric fields and their germination rate after the treatment with respect to non treated seeds were studied. The seeds used in the experiment were air dried and exposed to single and repetitive pulsed electric fields. The pulse generator is an in-house built MARX-GENERATOR with an average pulse width of few microseconds and peak voltage of 25KV. The effects of the parameters of pulsed system such as rise time, fall time, field strength and duration over which the pulse is exposed on the seed germination were studied. The results are presented.
03P-21: Estimated Electrical Power Delivery to a Plasma Channel Formed in
a Water Gap. M. J. Given, I. V. Timoshkin, M. P. Wilson,
S. J. Macgregor Department of Electronic and Electrical
Engineering, University of Strathclyde, Glasgow, United Kingdom
The breakdown of a liquid gap by a high voltage pulse is of interest in many industrial applications, as the expanding plasma channel formed in the gap leads to the formation of shockwaves in the liquid. The system therefore acts as a source for High Power Ultrasound. Such sources have found applications in mineral comminution [1], the processing of waste materials [2], as an alternative to shot peening as a method of hardening metals [3] and as an alternative to conventional rock drilling techniques.[4] If the pulse is supplied from a capacitor based power supply, an oscillating current and voltage is generally observed as the system forms a RLC circuit. A simple calculation of the instantaneous power dissipated in the plasma channel is not possible, due to the presence of an inductive component in the voltage measured across the plasma channel in the gap. However if the behaviour of this inductive voltage can be determined, it becomes possible to calculate the electrical power delivered to the plasma channel from the measured voltage and current data. The time varying behaviour of the system inductance can be calculated from the measured current transients when the gap breaks down[5]. This inductance is made up of the stray inductances in the system, the inductance of the plasma channel in the switch and the inductance of the plasma channel in the gap. By analysis of the current waveforms observed during breakdown of the gap and those observed when the gap is shorted, it is possible to separate the behaviour of the inductance of the plasma channel in the gap from the other inductances in the system. This allows the time varying inductive component of the gap voltage to be determined, allowing the calculation of power delivery to the gap to be made by considering the residual gap voltage and the behaviour of the measured current. This analysis has been performed on data obtained from the breakdown of a water gap and the delivery of energy to the gap with time has been derived for various applied voltages and gap separations. [1] Bluhm H, Frey W, Giese H, Hoppé P, Schultheiß C, and Sträßner R, 2000, Application of pulsed HV discharges to material fragmentation and recycling, IEEE TDEI, 7 625-36.
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[2] Wilson M.P, Balmer, L., Given, M.J., MacGregor, S.J., Timoshkin, I.V. An investigation of spark discharge parameters for material processing with high power ultrasound , Minerals Engineering, 20 (12), p.1159-1169, 2007 [3] Zhang W and Yao Y L, 2002, Micro scale laser shock processing of metallic components, J. Manufacturing Science and Engineering, Trans. ASME, 124 369-78. [4] Timoshkin I V, Mackersie J W, and MacGregor S J, 2004, Plasma channel miniature hole drilling technology, IEEE Trans. on Plasma Science, 32 2055-61 [5] Given, M. J.; Timoshkin, I. V.; Wilson, M. P.; MacGregor, S. J.; Lehr, J. M ,2007 Analysis of the current waveforms observed in underwater spark discharges, IEEE PPC, 2007, pp37 - 40
03P-22: Detection of the Onset of Pore Formation by Nanosecond-Time-
Resolution Pulsed Laser Fluorescence Microscopy Measurements on Plant Cell
Protoplasts W. Frey, T. Berghoefer, B. Flickinger
IHM, Forschungszentrum Karlsruhe, Eggenstein-Leopoldshafen, Germany
The field induced generation of hydrophillic pores in the plasmamembrane of biological cells, commonly referred to as electroporation, nowadays is applied for cell ingredient extraction, dewatering of biomass, bacterial decontamination and for a transfer of large molecules, drugs or DNA into the cell interior. The charging of the plasmamembrane of the targeted cells, which are suspended in a conductive buffer solution and exposed to electric field pulses, is a necessary condition for the formation of hydrophillic pores. For this work, the plasmamembranes of BY-2 tabacco protoplasts, which are filled into a microgap located on the microscope stage of a fluorescence microscope, were stained with a fast voltage sensitive fluorescent dye. 500 ns after the onset of the field exposure, the stained cells are illuminated by a 5 ns laser pulse. The changes of the fluoresence intensity of the light emitted from the stained plasmamembrane can be related to the transmembrane voltage change, caused by external electric field exposure. For a low external electric field E, the measurements show, that the membrane voltage Vm of a cell with a diameter of 2a initially shows the sinusoidal azimuthal dependence, like predicted by the relation Vm = 1.5 *E*a*sin(alpha), proposed by Cole. At a higher electric field strength, the membrane voltage first saturates at the anodic cell pole indicating the onset of enhanced pore formation. At a further increase of the electric field, this saturation becomes visible at the cathodic cell pole, too. This pronounced asymmetry in pore formation onset is caused by the high resting potential of plant cells. The conseqences for the determination of pulse parameters for an effective electroporation will be discussed.
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03P-23: Investigation of Drift Dynamics and Injection Stability of High-Current
Electron Beam with Picosecond Resolution
M. I. Yalandin1, A. G. Reutova1, K. A. Sharypov1, V. G. Shpak1, S. A. Shunailov1,
M. R. Ulmasculov1, G. A. Mesyats2 1Institute of Electrophysics, Ural Branch of
Russian Academy of Sciences, Ekaterinburg, Russian Federation
2Lebedev Physical Institute RAS, Moscow, Russian Federation
Injection stability and dynamic processes at the picosecond front of high-current electron beam were studied experimentally. Electron beams (200-300 keV; <1.5 kA; FWHM~0.5-3 ns; rise time ~200-300 ps) were injected by explosively-emissive tubular cathode and transported throughout drift vacuum chamber in longitudinal guiding magnetic field. Experiments layout was typical for vacuum Cerenkov-type HPM devices of millimeter-wave band, and for air-filled diodes producing the beams of running-away electrons. Two versions of current probes were used for diagnostics. For both options e-beam collector represented the edge of central electrode of 8-Ohm coaxial transmission line. In the first probe this line is connected in-series to stepwise one with a 50-ohm output to the oscilloscope. To reduce amplitude of a signal produced by an incident, kiloampere-range e-beam, a disk-type current collimator with narrow (~0.3 mm) radial slots was used. In the second version a single stepwise- or short conical junction to the 35-ohm measuring coaxial line was applied. Capacitive voltage divider made in a form of extended, low-resistance (< 1 Ohm) coaxial line was built inside the measuring line. This probe records a full current of non-collimated e-beam. The time resolution of the most fast probe (Option #1) was not worse than 30 ps. With the use of a slot-type collimator it was demonstrated, that subnanosecond front of e-beam is formed by chaotically distributed along the angle and non-isochronous sequence of the picosecond bursts of current. Appearance of temporary microstructure of the beam front varies from pulse to pulse and depends on a distance of e-beam drift. Registration of front of total e-beam current makes it possible to evaluate effective energy of electrons by time-of-flight method. Probable effects of sharpening of the beam leading edge will be discussed. Data of experiments will be compared with results of numerical PIC- simulation of dynamics of azimuthally uniform beam. Work supported by Russian Foundation for Basic Researches. Grant 08-02-00183 and Grant 07-08-12037.
03P-24: Atmospheric Glow Discharge Plasmas Using a Microhollow Cathode
Device* A. Lodes, R. D. Curry
Center for Physical and Power Electronics, University of Missouri-Columbia, Columbia, MO,
United States
Glow discharges are known to have relatively high electron densities even while maintaining stability. Applications of these discharges are numerous and include plasma reflectors and absorbers of electromagnetic radiation, surface treatment, thin film deposition, and gas lasers. Microhollow cathode devices have been shown to be excellent high electron density (up to 10^16 /cm^3) sources of glow plasma atmospheric air discharges. Under pD conditions on the order of 10 Torr-cm, the radial electric field created in the microhollow overtakes the axial electric field, oscillating electrons across the diameter of the hole. This effect leads to a glow discharge formed above the surface of the microhollow cathode. This geometry allows for large area arrays of highly stable glow discharges operated in parallel at atmospheric pressure. The University of Missouri-Columbia is currently developing a stable high-density large surface area plasma source. A microhollow cathode device with Cu electrodes, an Al2O3 substrate, and laser drilled 125µm cathode holes have been fabricated and investigated as a glow discharge plasma source. Illustrated are the physics behind the microhollow cathode relating to its high electron density, operation in atmospheric pressure, and generation of several discharges in parallel. Also presented are the results of several studies on the operation on variants of hollow cathode geometries. *Funding for the program was provided by ONR under contract number N00014-08-1-0266.
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03P-25: Pulse Power System for Waste Water Cleaning
Y. Y. Livshiz, O. Gafri Chief Technological Officer WADIS Ltd, Rehovot,
Israel Pulsed underwater discharge is used for waste water treatment. Waste water stream goes through camber with number of electrodes. Voltage of several tens of kilovolts is applied to the electrodes system with pulse rep-rate from10 to 100 pulses per second and pulse duration is in range of 10^-5 -10^-8 sec. Intensive action of such factors as shock wave, Ozone, UV-radiation, cavitations, high electrical field stimulate disintegration the microorganisms and provide the water disinfection The paper describes the experimental water treatment apparatus of industrial scale for production rate about 40 m^3/hour. The results are basis for creating the system for really municipal waste water apparatus of 250 m^3/hour and much more
03P-26: Application of Pulsed Power System for Water Treatment of the
Leachate H. J. Ryoo1, Y. S. Jin1, S. R. Jang2, S. H. Ahn2,
G. H. Rim1 1Industry Application Research Division, KERI,
Changwon, South Korea 2Dept. of Energy Conversion Technology,
University of Science & Technology, Daejeon, South Korea
This paper deals with the water treatment of the leachate from sewage filled ground by a pulsed power technology. Leachate from sewage filled ground should be treated below regulation level of COD in order to prevent environmental pollution and usually treated by a chemical method. Among the pollutants mixed in the leachate, chemical compounds of benzene series are known to be difficult to break down, and need to use high cost treat methods. The treatment of the benzene compounds by high power pulsed power supply was studied. For the high-rate, cost-effective treatment of leachate, pulsed power supply should have high repetition rates and require switching devices of long lifetime. In order to meet the demands of the above condition, pulsed power generator based on semiconductor switches using IGBTs as primary switches were developed. The experimental results verified that benzene compounds can be treated effectively by high voltage electric pulses, and this fact indicates that the treatment method by pulsed power source is a promising substitute.
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03P-27: The Optimal Design and Comparison of Power Supply for
Dielectric Barrier Discharge Ozone Reactor
B. Kim, H. Ju, K. Ko Electric Engineering Department, Hanyang
University, Seoul, South Korea
There numerous kinds of industrial application by using DBD (Dielectric Barrier Discharge) exist from medical to environmental researching field. Though discharging mechanism of DBD are deeply and widely investigated, DBD power supply and optimal design rules are not revealed well because applied voltage shape, voltage amplitude, operating frequency, required power, and duty rate are widely changed by reactor type and application requirements. Furthermore, currently noticed DBD applications are pointed on high pressure gas discharging physics such as ozone generating application. In case of the ozone generating application, circuit design and operation conditions of power supply are depended on configurations of DBD reactor that indicate reactor size, oxygen gas pressure, gas flow path, gap distance between electrode, dielectric material, and impedance changing of reactor when discharging is started. In general, the DBD power supply is designed and based on required power which includes voltage amplitude and current. But, when the discharging in the DBD reactor is proceeded, the required power and impedance of DBD reactor is changed. Due to the reason, it is important to match impedance of the DBD reactor at the DBD power supply. In this paper, it is shown that comparison of several types on DBD power supply which contain E-type resonant power supply, fly-back type, and simple inverter type of DBD power supply. Through the comparisons with plane DBD reactor, there are measured generation rate of ozone, power factor when the discharging is proceeded, and stability of DBD reactor and power supply. Based on the experimental comparison, this paper proposes that impedance matching and applied voltage alternation when the discharging is proceeded are most important for stable and high efficient generating of ozone.
03P-28: Ozone Synthesis Using Streamer Discharge Produced by Ns Pulse Voltage
under Atmospheric Pressure K. Takaki1, S. Mukaigawa1, T. Fujiwara1, T. Go2
1Faculty of Engineering, Iwate University, Morioka, Iwate, Japan
2Ichinoseki National College of Technology, Ichinoseki, Iwate, Japan
A ns pulse voltage was used to drive a coaxial geometry corona reactor to synthesis ozone with high energy yield. The ns pulse voltage was produced using an inductive energy storage system pulsed power generator using semiconductor opening switch (SOS) diodes. First recovery diodes were used as SOS diodes in the inductive energy storage system pulsed power generator to produce short-pulse high voltage with high-repetition rate. The pulse voltage of 12 ns width and 17 kV peak voltage was produced at charging voltage of -5 kV and was applied to a 1 mm diameter center wire electrode in the coaxial geometry reactor. The copper cylinder of 19 mm inner diameter was used as outer electrode and was connected to a ground. The ozone yield of 230 g/kWh was obtained using ns narrow pulse voltage. This value is almost 20% higher than 190 g/kWh obtained by 60 ns width pulse.
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03P-29: Development of Compact Ozonizer Using Wire to Plate Electrodes S. Ueda1, F. Tanaka1, K. Kouno1, M. Akiyama1,
T. Sakugawa1, H. Akiyama1, Y. Kinoshita2 1Graduate School of Science and Technology,
Kumamoto University, Kumamoto, Japan 2Toyota Motor Corporation, Susono, Japan
Recently, ozone has used widely for industrial applications. For example, a water treatment, cleaning a semiconductor substrate and bleaching a pulp. The conventional ozonizers such as silent discharge method or barrier discharge method with cooling water could not be compact equipment. We have been studied and developed an ozonizer using a compact size all solid-state pulsed power modulator for industrial applications. This compact pulsed power modulator (CPPM) consists of thyristor switches and magnetic pulse compression circuit. The CPPM can generate an output peak voltage of 20 kV with voltage rise time of 50 ns, and pulse repetition rate is 500 pulses per second (pps). Input power is 250 W. We have studied and developed compact ozonizer using wire to plate electrodes. Size of the compact ozonizer is 250 mm x 350 mm x 50mm. We applied positive high voltage pulses to wire electrodes, and then high repetition rate streamer discharges are generated. This compact ozonizer is no using cooling water because the streamer discharge is nonthermal discharge plasma. We used the CPPM and the compact ozonizer, and then we attained ozone concentration of over 5 g/m3 and ozone yield of 86 g/kWh with air flow rate of 20 L/min.
03P-30: Spectral and Optical Investigations of Electric Arc Alternating
Current Plasma Generators Using Carbon Dioxide as a Plasma Forming
Agent P. G. Rutberg, A. V. Nikonov, R. V. Ovchinnikov,
A. V. Pavlov, S. D. Popov, E. O. Serba, V. A. Spodobin, A. V. Surov
Institute of Electrophysic and Electricpower RAS, Saint-Petersburg, Russian Federation
Low temperature plasma having high volumetric concentration of energy for a long time draws attention mainly due to the opportunity of realization of the processes which in usual conditions either do not occur, or go very slowly and inefficiently. Carbon dioxide plasma is one of the most optimum environment for a lot of the manufactures connected with production of synthetic products, hazardous waste processing and also with the processes of solid fuel gasification etc. Besides, Carbon dioxide plasma is very promising in various technological processes of machine-building, and metal-mining industry owing to the unique properties, such as high enthalpy, oxidation-reduction character, ecological compatibility, etc. Therefore the problem of development and designing of electric arc generators using carbon dioxide as a plasma forming agent is of the hour. The paper is concerned with the results of spectral and optical measurements of the plasma generators of alternating current working on carbon dioxide. Spectra of emission radiation of carbon dioxide plasma describing its composition are shown. Temperature dependence in the plasma generators flame of the gas flow rate is investigated. The qualitative picture of behavior of an arc and plasma generator flame at different stages of the discharge received by high-speed shooting is studied.
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03P-31: Investigation of Electrode Units of Alternating Current Plasma
Generators. Ways of Increase in Lifetime of Operation and Durability.
V. E. Kuznetsov, A. A. Safronov, I. I. Kumkova, R. V. Ovchinnikov, V. N. Shiryev, K. A. Kuzmin,
O. B. Vasilieva IEERAS, St.Petersburg, Russian Federation
Maintenance of maximal duration of continuous operation of electrodes at use of various plasma gases (air, СО2, steam, etc.) will considerably extend the technological sphere of application of plasma generators, allow its efficient use with minimal costs in various processes, such as pyrolysis of wood, plasmachemical processing of coals, synthetic fuel production, etc. The results of researches carried out at the development of plasma generators, using a steam-gas mixture as a plasma-forming environment is presented. Modern methods of manufacturing of electrode materials allow creation of complex structure compositions, by means of introduction of a refractory material in a copper matrix that considerably increases its erosive resistance. The task of the present work became carrying out of researches of erosive properties of various materials and designs of electrodes for the high-voltage steam-air alternating current plasma generator with power up to 100 kW over a wide range of working parameters, charges of working gas and mass ratio of steam and air.
03P-32: Nitric Oxide Generated by Atmospheric Pressure Air Microplasma
K. Matsuo Science and Technology, Kumamoto University,
Kumamoto, Japan
The production of atmospheric pressure air microplasma jet requires no vacuum devices and it uses air gas, which considerably reduces the investment cost. Atmospheric pressure microplasma jets have recently been used for industrial and medical applications, such as local dental treatment, inner surface treatment of capillaries, stimuli of microorganisms, and local cleaning of semiconductor devices. The other advantage of the atmospheric pressure air microplasma jet is its capability to irradiate plasma to a narrow area. It is also ultra-portable and can be miniaturized easily. In the recent years, several investigators have reported that plasma irradiation on a wound improved and accelerated the wound healing process. Nitric oxide (NO) content of the microplasma jet is believed to help the wound healing. Therefore, in this research quantitative measurements of NO have been performed. Beside NO generation, the microplasma jet produces toxic and pollutant nitrogen dioxide (NO2) and ozone gases. The quantities of the generated NO2 and ozone have been measured and evaluated. In order to produce the highest quantity of the NO gas, the design and performance parameters of the microplasma jet, such as inner gap and gas flow rate, have been changed and their effects on the NO generation have been investigated. The results are used to optimize the characteristics of the air microplasma jet for medical applications.
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03P-33: The Electric Arc Alternating Current Plasma Generator on Steam-Air
Mixtures for Plasmachemical Applications
P. G. Rutberg, S. D. Popov, A. V. Surov, E. O. Serba, A. V. Nikonov, A. V. Pavlov,
I. I. Kumkova, O. B. Vasilieva Institute for Electrophysics and Electric Power, Russian Academy of Sciences, St.Petersburg,
Russian Federation
The alternative technologies of liquid fuel production, including plasma pyrolysis of organic fuel and organic containing waste, are gaining in importance in relation to the problem of shortage of natural resources, above all gas and oil. Electric arc plasma generators operating on steam or steam-air mixture are the most suitable devices for the realization of processes of hydrocarbonic raw material processing. Now these systems are under development in IEE RAS. The work is concerned with the investigation of electric parameters of high voltage alternating current plasma generators with rod electrodes and power of up to 100 kW using steam-air mixtures. Current voltage characteristics, voltage flow rate characteristics, characteristic oscillograms of operation, results of plasma jet research, and also the results of investigation of influence of plasma forming environment composition (ration of steam and air flow rates) on the electric arc parameters are presented in the paper.
03P-34: Intracellular DNA Damage in CHO Cells Induced by Application of Burst RF
Fields M. Yano1, N. Nomura1, K. Abe1, S. Katsuki2,
H. Akiyama2 1Graduate School of Science and Technology,
Kumamoto University, Kumamoto, Japan 2Bioelectrics Research Center, Kumamoto
University, Kumamoto, Japan
Biological effects of intense pulsed electric fields with wide or narrow band frequency spectra have been intensively investigated in the last decade. The pulsed electric fields (PEFs) are capable of giving unique stresses that depend on its pulse duration, rise time and amplitude. The nanosecond pulsed electric fields (nsPEF) cause intracellular effect whereas micro- to millisecond PEFs affect the membrane. We have used intense burst sinusoidal electric field (IBSEF) to give biological targets a well-defined field with respect to frequency, field strength and duration. The use of the IBSEF enables us to control the parameters independently. Our previous study [1] demonstrated that the degradation of intracellular DNA of Chinese hamster ovary (CHO) cells are induced by the application of non-thermal 100 kV/m, 100 MHz IBSEF. Here, we describe the dependence of the DNA damage on frequency and strength of the IBSEF. The IBSEFs with various strengths of up to 200 kV/m and with various frequencies in the range between 0.1 and 100 MHz were applied to CHO cells in the suspending medium. The application of IBSEF with burst duration of 200 s causes the slight temperature increase of at most 1.3˚C that may not be significant for the DNA damage. The DNA damage was detected by means of comet assay and the degree of the DNA damage was evaluated by Olive moment method. The experiment indicates that the degree of the DNA damage depends on the frequency as well as on the field strength. At the frequency of 100 MHz that is sufficiently high for the field to penetrate into the cell, the DNA was damaged with the field strength exceeding 10 kV/m. At the field strength of 100 kV/m, there is a critical frequency at 1 MHz for the DNA damage. At the frequency exceeding 1 MHz, the significant DNA damage was detected whereas no damage was detected with the frequency less than 1MHz. There is no significant frequency dependence in the range between 3 and 100 MHz. The comet pattern in the case of the IBSEF application appears to be different from that in the case of ultraviolet irradiation, which implies that the IBSEF might be a different type of stress from the ultraviolet irradiation for CHO cells. Additionally, the electrophoresis analysis of isolated genome DNA exposed to the IBSEF. It is considered that the intracellular electric fields more than
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approximately 10 kV/m are suggested to activate the biological process leading to the DNA break. [1] S. Katsuki, N. Nomura, K. Koga, H. Akiyama, I. Uchida, S.-I. Abe, IEEE Trans. Dielectr. Electr. Insulat., Vol. 14, pp.663-668 (2007)
03P-35: Pulsed Electric Field Induced Changes in Dielectric Properties of
Biological Cells J. Zhuang, S. Beebe, K. H. Schoenbach,
J. F. Kolb Frank Reidy Research Center for Bioelectrics,
Old Dominion University, VA, United States
The initial response of a cell to an applied electric field is determined by its dielectric properties. Conversely, the exposure to an electric field can alter these parameters [1]. An understanding of the phenomena helps not only to explain the interaction mechanisms but also helps to determine exposure conditions that preferentially target specific cells, such as tumor cells. We have investigated the dielectric properties of Jurkat cells, a malignant human T-cell line, before and after application of microsecond and nanosecond pulsed electric fields by means of time domain dielectric spectroscopy. By applying the measured data to electrical models of the cell (single and double shell), changes of dielectric parameters of the cell membrane, cytoplasm, nuclear envelope, and nucleoplasm were obtained. For both microsecond and nanosecond exposures, conductivities are expected to decrease dramatically following pulse application, suggesting that membrane poration had occurred [2]. This effect should be consistent with the transmembrane potential measurement using fluorescence dyes [3]. For nanosecond pulse duration, we predict that changes in the dielectric properties of nuclear envelope, and nucleoplasm are more pronounced than for microsecond pulse duration, suggesting intracellular structures are more affected by shorter pulses. Acknowledgment This research was made possible through support from Old Dominion University - Office of Research. [1] A.L. Garner, N. Chen, J. Yang, J.F. Kolb, R.J. Swanson, K.C. Loftin, S.J. Beebe, R.P. Joshi, K.H. Schoenbach, "Time domain dielectric spectroscopy measurements of HL-60 cell suspensions after microsecond and nanosecond electrical pulses," IEEE Trans. Plasma Sci. 32 (2004) 2073. [2] A.L. Garner, G. Chen, N. Chen, V. Sridhara, J.F. Kolb, R.J. Swanson, S.J. Beebe, R.P. Joshi, K.H. Schoenbach, "Ultrashort electric pulse induced changes in cellular dielectric properties," BBRC 362 (2007) 139. [3] W. Frey, J.A. White, R.O. Price, P.F. Blackmore, R.P. Joshi, R. Nuccitelli, S.J. Beebe, K.H. Schoenbach, J.F. Kolb, "Plasma Membrane Voltage Changes during Nanosecond Pulsed Electric Field Exposure," Biophysical J. 90 (2006) 3608.
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03P-36: Sensitivity of Some Biological Tissues and Cellular Cultures to
Repetitive Sub-Microsecond Microwaves V. V. Rostov1, M. A. Bolshakov1, I. R. Knyazeva1,
O. P. Kutenkov1, L. P. Zharkova1, M. A. Buldakov2, N. V. Litvyakov2,
N. V. Cherdyntseva2 1Russian Academy of Sciences, High Current
Electronics Institute, Tomsk, Russian Federation 2Russian Academy of Medical Sciences, Institute
of Oncology, Tomsk, Russian Federation
The biological effect of pulse-periodic microwave radiation (PPMR) is more expressed as compared with continuous regime. PPMR effect depends on pulse repetition frequency and specific absorbed rate (SAR). Authors have been observed these dependencies with non-relativistic magnetron (10 GHz, duration of pulse 100-300 ns, pulse repetition frequency 4-25 Hz, peak power density 0.7-17.4 kW/cm2, averaged SAR 150 W/kg). Few thousand pulses exposure of different tissues and culture of cells changes their functional characteristics, in all cases the effects depend on pulse repetition frequency. In particular, the exposure inhibited the proliferation of tumor cells mastocytoma Р-815 and Ehrlich carcinoma at 0.9-1.5 kW/cm2, the maximum effect was observed at pulse repetition frequency 8, 10 and 13 Hz. Such PPMR effect was caused probably by apoptosis start, since it was observed the activation of caspase-3 on average by 30%. Along with inhibiting action of PPMR it was revealed stimulation action on the full-thickness wounds healing and inclusion process of Н3-thymidine into spleen-DNA of intact mice (0.9-3.5 kW/cm2). The PPMR effect can be caused by oxidative modification of macromolecules, since local irradiation of mice liver was accompanied by changes in oxidative modification level of lipids and protein in hepatocytes and blood serum. The changes of these characteristics showed a complicated dynamics during 6-72 hours after exposure. In this period of time it wasnt find correlated connections between couples lipids proteins or liver blood serum at all pulse repetition frequencies. It allows suppose that PPMR exposure initiates chain of independent parallel processes in organism, which initiation location are mitochondria.
03P-37: Pulse-Modulated Microwaves Propagation Inside of a 3D Non-Coordinate Shape Heart Model
S. Asmontas1, L. Nickelson1, R. Martavicius2, V. Engelson3
1Terhertz's Electronic Laboratory, Semiconductor Physics Institute, Vilnius, Lithuania
2Electronic System Department, Gediminas Technical University, Vilnius, Lithuania
3Department of Computer Science, Linkoping University, SE-58183, Linkoping, Sweden
A human heart may be under influence of the microwave radiation for the medical examination of patients or because of hazardous environment [1]. The electrodynamical rigorous solution of Maxwells equations related to the microwave pulse propagation in a three-dimension heart model is presented here. The boundary problem was solved by using the singular integral equations (SIE) method [2]. Our solution, obtained by our SIE method, is electrodynamically rigorous. The false roots do not appear and the boundary conditions have to be satisfied only the surfaces dividing different materials. We formulated our electrodynamical problem like this: a point source radiates a microwave pulse into a 3D heart model. The heart model has an intricate shape and it limited by a non-coordinate shape surfaces. The surfaces of the 3D heart model were created in the 3D Studio MAX. The heart model consisted of cardiac muscle and the right and left atriums with ventricles cavities which were filled with blood. In our calculations the cavities were filled with blood with the permittivity 58-i19 and the walls of the heart consisted of myocardium tissue with the permittivity 55-i17. The sizes of heart model were 13 cm, 9 cm and 8cm. We assumed the monochromatic carrier microwave with the frequency 2.45 GHz was modulated with a rectangular and a triangular video pulse. We calculated for the on-off time ratio equal to 5. We investigated the electric field distribution of the microwave pulses in different planes of the heart in the same time moment. The pulse durations were always equal to 20 ms. It is important to note five factors which determine the microwave pulse propagation in our calculations: 1) the modulating signal which is a video pulse we describe by formula as a sum of harmonics; 2) a number of harmonics which approximate the modulating video pulse is chosen proportional to the on-off time ratio of the pulse; 3) a number of harmonics depends on the form of a video pulse; 4) harmonics of the microwave signals can reflect repeatedly from the interior and external heart model surfaces; 5) the harmonics interference occurs inside of the heart model. We investigated microwave electric field distributions at several cross-sections of a 3D heart model. We found
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that the amplitude of the electric field decreased different dependent on the direction while the microwave pulses were moving away from the antenna tip. References: [1] Kubacki R. Biological interaction of pulse-modulated electromagnetic fields and protection of humans from exposure to fields emitted from radars. In Conf. Proc. MIKON-2008, 1921 May 2008, Wrocław, Poland, Vol. 2, p. 360-366 (2008). [2] Nickelson L., Shugurov V. Singular integral equations methods for the analysis of microwave structures. Leiden−Boston: VSP Brill Academic Publishers (ISBN 90-6764-410-2), 348 p. (2005).
03P-38: Spectroscopy of Non-Thermal Atmospheric Helium Plasma Needle
B. Onyenucheya, T. M. DiSanto, J. L. Zirnheld, K. M. Burke
Energy Systems Institute, University at Buffalo, Buffalo, NY, United States
A novel non thermal plasma needle was developed to study its effects on keratiocytes and melanoma cells. The plasma needle operates in 80 KHz to 100 KHz frequency range, while the plasma sustaining electrodes potential is approximately 600 volts. This paper will discuss the characterization of the plasma needle via set of diagnostic techniques in an effort to identify characteristics of the plasma that affects the cells. A spectrograph was used as a noninvasive technique to study the plasma emission. The effects of the plasma temperature, derived from the plasma wavelength and intensity, on cells are discussed in the paper.
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03P-39: Study on the High Frequency High Voltage Power Supply Used for
Leak Inspection Y. Sun1, P. Yan1, Y. Gao1, J. Shao2
1Institute of Electrical Engineering,Chinese Academy of Sciences, Beijing, China
2School of Physical Science and Technology, Huanggang Normal University,
Huanggang,Hubei, China
One of the most important processes in the pharmaceutical industries is the leak detection to prevent pollution by bacteria. The high frequency high voltage method is proven to have a detection accuracy of at least 0.5m.There are pinhole detecting machines for medicines in ampoules or soft bags[1]. The paper introduces the leak inspection principle of the high frequency high voltage power supply. It is based on the dielectric barrier discharge(DBD) technology. When a high voltage is applied on the electrodes, glow discharge will occur between the high voltage electrode and the wall of the plastic container. If the solution leaks out from the micro holes generated during the encapsulation process, the discharging current will vary. We can verdict the leak according to the variation of the current. The power supply is mainly composed of a high frequency inverter using the IPM(Mitsubishi Corp.) as the switching component, a high voltage transformer, high voltage electrode (needle electrodes for 500ml PP bottles and plate electrode for PVC soft bags), ground electrode and the leak signal output circuit using a current sensor. The working frequency is 30-40kHz which varied with the different production lines and electrode structures. We established the circuit model of the system, and experimental results were in good accordance with the simulations. Further research will be focused on the inspection accuracy, reliability and stability. Reference 1.Haruo Sasaki, Kunio Kamimura. Pinhole Inspection Machine for Sealed Packages:for Detection of Pinholes of 0.5m or below. Packag. Technol. Sci. Vol 10:109-118, 1997.
03P-40: Effect of Frequency of Burst Pulse High Electric Field and Burst Pulse High Intensity Electromagnetic Wave on
Microorganisms Y. Minamitani, Y. Kuramochi, T. Saito, T. Ueno Graduate School of Science and Engineering, Yamagata University, Yonezawa, Yamagata,
Japan
As applications of pulsed power, there are biological and medical applications, like sterilization, cancer treatment, etc. We have developed a high frequency and high voltage burst pulse generator for investigating biological effect of high intensity and high frequency electric field on cells. The generator can generate a burst pulse with single frequency component and change the frequency component of the burst pulse. The highest frequency component is 70 MHz. Maximum duration of the burst pulse is 100ns. The highest amplitude of the out put voltage is 9 kV. The effect of the frequency of pulsed high electric field on yeast and E. coli was investigated by applying high voltage pulse to a cuvette by the generator. The frequency components applying to those were 20~70 MHz, and maximum field strength was 90 kV/cm. The numbers of pulses were 5, 10 and 20. Survival ratios of yeast decreased at all frequency and every number of pulses. At 70 MHz of every number of pulses, survival ratios of yeast were most decreased. The survival ratio of yeast decreased to 30 % at the frequency of 70 MHz on 20 pulses. Meanwhile, a survival ratio of E. coli decreased only 25 % at 70 MHz by applying 20 pulses. In experiment of radiating electromagnetic wave to microorganisms, other generator was used for radiating electromagnetic wave [1][2]. This generator can radiate burst pulse electromagnetic wave with the frequency components of about 135 and 280 MHz in water. Yeast was used in this experiment. The intensity of electric field of electromagnetic wave radiated for yeast was 10 kV/cm. On 100 and 200 pulses, survival ratios of yeast decreased to 70 and 35 %, respectively. The pulsed voltage was also applied directly to yeast in the cuvette using the same generator without radiating electromagnetic wave. On 100 pulses, the survival ratio of yeast decreased to 70 % as with the result in electromagnetic wave. [1] Y. Minamitani, Y. Ohe, T. Ueno, Y. Higashiyama; “Output Characteristics of High Power Pulsed Electromagneticwave Generator for Medical Applications Using Water Gap Switch and Water Capacitor”, Proc. of The 34th IEEE International Conference on Plasma Science and the 16th IEEE International Pulsed Power Conference, pp.1240-1243 (2007) [2] T. Ueno, Y. Ohe, S. Kato, Y. Minamitani, “The Intensity Distribution of Electric Field Radiating
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from the High Power Pulsed Electromagnetic Wave Generator with Water Gap Switch and Water Capacitor”, Proc. of 28th International Power Modulator Conference & High Voltage Workshop 2008, pp. 322-325 (2008)
03P-41: Investigation of Operating Modes of Electric Arc Alternating Current Plasma Generators Using Carbon
Dioxide as a Plasma Forming Agent P. G. Rutberg, A. A. Safronov, A. V. Surov,
S. D. Popov, G. V. Nakonechny, R. V. Ovchinnikov, V. A. Spodobin,
S. A. Lukyanov, S. A. Kuschev Institute for Electrophysics and Electric Power, Russian Academy of Sciences, St.Petersburg,
Russian Federation
Nowadays one of the basic ecological problems is increasing of carbon dioxide emission. By now the technologies allowing catching carbon dioxide and its storage in underground storehouses are developed. However the best alternative to warehousing will be high-temperature plasma recycling or use of carbon dioxide in plasma technologies of synthesis artificial fuels production. Carbon dioxide can be used as a plasma-forming agent in technologies of plasma gasification of organic substances (coal, peat, lignite, organic containing municipal waste) for synthetic liquid fuel production. It is also known that at temperatures above 4000 grades CO2 molecule dissociates in CO + O, at temperatures above 6000 grades CO2 molecule disintegrates in oxygen and carbon, which can be precipitated at fast cooling. It is possible to achieve such temperatures in the electric discharge chambers of electric arc alternating current plasma generators developed in IEE RAS. The paper is devoted to the results of investigation of electric arc alternating current plasma generators with power up to 300 kW at use of carbon dioxide as a plasma-forming environment. Current voltage characteristics, voltage flow rate characteristics, characteristic oscillograms of operation, and results of plasma jet research are given in the paper
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03P-42: The Effect of Spraying of Water Droplets and Location of Water Droplets
on the Water Treatment by Pulsed Discharge in Air
T. Kobayashi1, T. Handa1, Y. Minamitani1, Y. Tashima2, T. Nose2
1Graduate School of Science and Engineering, Yamagata University, Yonezawa, Japan
2Sekisui Chemical Co.,Ltd., Kyoto, Japan
We have been studying water treatment using pulsed streamer discharge generated in atmosphere of air injecting water droplets for decomposing organic compounds in water [1][2]. The pulsed streamer discharge can generate OH radicals, ozone, ultraviolet radiation and high-energy electrons that decompose organic compounds in water. However, in water, breakdown voltage for generating streamer discharge is high and it is difficult to make uniformly streamer discharges in volume. In contrast, in air, breakdown voltage for generating streamer discharge is lower than that in water and it is easy to make uniformly streamer discharges in volume. Therefore, water including organic compounds is sprayed as water droplets into the discharge area in air. In this study, the effects of spraying of water droplets and location of water droplets in discharge area have been investigated. A reactor to generate streamers has a coaxial electrode that consists of a cylindrical mesh of stainless steel of inner diameter of 36 mm and a stainless steel wire of outer diameter of 0.28 mm. The electrode length is 300 mm. Positive pulsed voltage is applied to the wire electrode, and cylindrical electrode is grounded. Pulsed voltage was 25kV with pulse width (FWHM) of 70ns. A water solution of organic dye, indigo carmine, was used for sample. Repetition rate for the pulsed voltage was 100 pps. Flow rate from shower nozzle into the discharge area was 50mL/s. Decolorization rate of water droplets including indigo carmine was measured by a UV and visible-light absorption spectrometer. In results of the experiments, it has been shown that spraying the water solution as water droplets into the discharge area is efficient for faster treatment compared to the water solution flowing along the inner wall. In addition, it has been shown that the decolorization rate of water droplets including indigo carmine was highest at the location near the cylindrical electrode of the reactor. [1] Yasushi Minamitani, Satoshi Shoji, Yoshihiro Ohba, Yoshio Higashiyama, “Decomposition of Dye in Water Solution by Pulsed Power Discharge in a Water Droplets Spray”, IEEE TRANSACTIONS ON PLASMA SCIENCE, Vol. 36, pp.2586-2591 (2008)
[2] Taiki Handa, Yasushi Minamitani, “The Effect of a Water Droplets Spray and Gas Discharge in Water Treatment by Pulsed Power”, IEEE TRANSACTIONS ON PLASMA SCIENCE, Vol. 37, pp.179-183 (2009)
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03P-43: Efficient Streamer Plasma Generation
A. J. M. Pemen, G. J. J. Winands, Z. Liu, E. J. M. V. Heesch, T. H. P. Ariaans
Electrical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands
In addition to being interesting phenomena to study, discharges and streamers can also be used for several purposes. Gas cleaning techniques using non-thermal plasma are slowly introduced into industry nowadays, as a replacement for existing gas cleaning techniques. For large scale, industrial, application of non-thermal plasma, several challenges arise, like increasing the scale, safety, long life-time, costs reduction, and so on. In the past we already demonstrated the possibility to design large scale (10-20 kW average power) pulsed corona plasma systems. By optimizing the matching between source and reactor, the electrical energy efficiency (from mains to reactor) was increased to over 90 percent. To increase the feasibility of streamer corona systems, the chemical efficiency has to be increased as well, i.e. ensure that the available energy is used for the desired chemical reactions. Several authors have already observed that, by changing the characteristics of the power source, the chemical efficiency of the system changes. The link between power source and chemical process is formed by the streamer plasma. Here we present investigations on nanosecond pulsed corona systems. We give an overview of the current status of available pulsed power techniques for large volume corona plasma generation. We report on the influence of high-voltage pulse parameters on the chemical efficiency. O-radical yields will be determined from ozone measurements at the outlet of the plasma reactor. The effect of varying high-voltage pulse parameters on the spatial and temporal development of the streamers are monitored with a fast (5 ns gate-time) ICCD camera.
03P-44: Exhaust Gas Treatment by 5ns Pulse Generator
T. Matsumoto1, D. Wang2, T. Namihira3, H. Akiyama3
1Department of Computer Science and Electrical Engineering, Kumamoto University, Kurokami 2-
39-1, Kumamoto, Japan 2Priority Organization for Innovation and
Excellence, Kumamoto University, Kurokami 2-39-1, Kumamoto, Japan
3Bioelectrics Research Center, Kumamoto University, Kurokami 2-39-1, Kumamoto, Japan
The air pollution from combustion of the fossil fuel became worse and causes the environmental problem. The conventional methods such as SCR method, Electron Beam method and Lime-gypsum method could not treat exhaust gases completely. In addition, the energy efficiency and the cost in the conventional ways are still negative situation. In recent years, the pollution control techniques using electric discharge plasmas which could attract attention as the low cost and high energy efficient exhaust gas treatment method, have been widely studied. In our laboratory, the pulsed streamer discharge plasmas which are one of the non-thermal plasma have been used to treat exhaust gases. Since a pulse width of applied voltage has a strong influence on the energy efficiency of the removal of pollutants, the development of short pulse generator is of paramount importance for practical applications. In this work, ns pulse generator which can output the 5ns pulsed voltage is developed and the exhaust gas treatment by ns pulse generator was demonstrated. As the results, the experiment gave some characteristics of the NO removal using the ns pulsed streamer discharge. For one thing, the polarity and the amplitude of applied voltage to the reactor have significant influence on the improvement of NO removal. Next, it was clear that the longer length of and the smaller diameter of the coaxial discharge reactor give the higher NO removal ratio. Moreover, it turned out to be that the existence of O2 and water vapor in the gas increases NO removal ratio widely. The most remarkable point of this work is neither such characteristics nor, 100 % of NO removal ratio. From the experimental results, it was confirmed that the ns pulsed discharge has great advantage in energy efficiency for NO removal to sub-μs pulsed discharge or other discharge methods. Under the best condition in this work, the NO removal energy efficiency of 2.3 mol/kWh (= 69g/kWh) was demonstrated at 70 % of NO removal ratio (initial NO concentration = 200ppm). This is extremely high efficiency.
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03P-45: Consideration of Parallel and Serial Coaxial Reactors for NOx
Treatment by Nanosecond Pulsed Power Discharge
F. Fukawa1, N. Shimomura1, S. Yamanaka1, T. Yano1, Y. Yokote1, K. Teranishi1, H. Akiyama2,
H. Itoh3 1The University of Tokushima, Tokushima, Japan
2Kumamoto University, Kumamoto, Japan 3Chiba Institute of Technology, Narashino, Chiba,
Japan
Nitrogen oxides (NOx) are one of the air pollutants that cause acid rain. While the principal method of NOx treatment is a discharge chemical treatment, the treatment using pulsed power has been developed. A nanosecond pulsed power generator has been developed and NOx treatment experiment is conducted. As the width of pulsed power shortens, the efficiency of treatment will be improved but the issues about load matching and control of arc discharge become difficult. Then, the parallel- and serial- connections of reactors are considered. The reactor consists of wire and cylinder electrodes and has a coaxial structure. Efficiency of the parallel connection is higher than the serial connection. In this experimental condition, three parallel reactors is the highest efficiency in all reactor configurations. Since load matching is an important matter for nanosecond pulsed power, the parallel connection would improve the treatment efficiency. Moreover, discharge volume in reactors would increase. The configuration of reactors for high efficiency of NOx treatment will be reported in detail.
03P-46: Pulsed Discharge Plasma Generated by Nano-Seconds Pulsed
Power in Atmospheric Air D. Wang1, T. Namihira2, H. Akiyama3
1Priority Organization for Innovation and Excellence, Kumamoto University, Kumamoto,
Japan 2Bioelectrics Research Center, Kumamoto
University, Kumamoto, Japan 3Graduate School of Science and Technology,
Kumamoto University, Kumamoto, Japan
Non-thermal plasma produced by pulsed power discharges in atmospheric pressure gases have been studied for various applications such as removal of hazardous environmental pollutants in gases, ozone generation and medical applications. For the industrial applications, its energy efficiencies become one of the most important factors. Several methods based on non-thermal plasma have been reported at various energy efficiencies. However, further improvement to obtain the higher efficiencies is required to be put to practical use. In our previous studies, the effect of the pulsewidth at a fixed applied voltage on NO removal concentration was investigated at 40, 60, 80, 100, and 120 ns. Its results showed that the removal energy efficiency increases with decreasing pulsewidth. Therefore, the development of a short pulse generator has been carried out. A nano-seconds pulsed generator that has voltage rise time and fall time of 2 ns each, a pulse duration of 5 ns, and peak pulsed voltage of 100 kV was built. On the other hand, the observation of discharges created by short duration pulsed voltage is an essential aspect for understanding the plasma physics of this growing field. In the present work, the propagation of the pulsed discharges was observed by both framing images and streak images. To discuss the effect of pulsewidth, the results of a Blumlein line generator with a pulsewidth of 100 ns and the nano-sedonds pulsed generator with a pulsewidth of 5 ns were compared. As the results, the discharge phase showed streamer discharge and glow-like discharge in case of 100 ns. During the glow-like discharge phase, the gas temperature increased about 150 K, and the electrode impedance showed a significant change which is concerned for the impedance mismatching between the power source and the electrode. These factors can cause the decrease of the energy efficiency. On the other hands, the discharge phase showed only the streamer discharge in case of 5 ns. The observed propagation velocity of the streamer heads in case of 5 ns was eight times faster than that of 100 ns. More results will be discussed at the presentation.
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03P-47: Purification of High Conductive Liquid Using Gas-Liquid Phases
Discharge Reactor K. Takahashi1, Y. Sasaki2, S. Mukaigawa1,
K. Takaki1, T. Fujiwara1, N. Satta2 1Faculty of Engineering, Iwate University, Iwate,
Japan 2Faculty of Agriculture, Iwate University, Iwate,
Japan
Water purification by streamer discharge using pulsed power generator under the high conductivity water containing pollutants has been investigated. A gas-liquid separated reactor was developed to treat high conductive solution. A wire electrode was placed in the gas phase and a plane electrode was immersed in the water. The pulsed high voltage generated by the six stacked Blumlein line was applied to the wire electrode to generate streamer discharge in gas phase, which propagated into the air bubble injected into the water. Indigo carmine solution was employed as a specimen. Natrium chloride was used to adjust the solution conductivity in the range from 10 to 30000 microS/cm. The solution of 30000 microS/cm conductivity was successfully decolorized at energy efficiency of 75 mg/Wh. Some species of gas such as room air, oxygen, nitrogen and argon was injected to clarify reactions of the decolorization. The result showed that the ozone produced by gas phase discharges mainly contributed to decolorize the solution.
03P-48: Improvement of Efficiency for Decomposition of Organic Compound in Water Using Pulsed Streamer Discharge in Air with Water Droplets by Increasing
of Residence Time T. Sugai, T. Abe, Y. Minamitani
Graduate School of Science and Engineering, Yamagata University, Yonezawa, Japan
Water treatment using pulsed streamer discharge in water has been studied currently. The pulsed streamer discharge in water generates active species that decompose organic compounds in water. However, the system for generating streamer discharge in water needs big battery for applying high voltage and high power, because the breakdown electric field of water is high. To solve this problem, we have studied the method spraying water droplets into discharge space in air whose breakdown electric field is lower than that in water, and have demonstrated that the method can decompose organic compounds faster in low energy consumption [1][2]. In addition, to obtain higher decomposition rate by increasing of residence time of water in the discharge space has been investigated. Two type reactors were designed to increase the residence time of water in discharge space in air. One of the reactors has pellets packed into a cylindrical electrode, and another has fluorocarbon wires weaving like many cobwebs into a cylindrical electrode. The treatment rate of the reactor with packed bed of the pellets was lower than that without the pellets because the discharge space was narrow by the pellets. Meanwhile, the treatment rate of the reactor weaving the fluorocarbon wire was higher than that without the fluorocarbon wire. It is supposed that the treated water was exposed to more streamer discharges because the residence time of water was increased and the discharge space was almost same as the reactor without the fluorocarbon wire. [1] Yasushi Minamitani, Satoshi Shoji, Yoshihiro Ohba, Yoshio Higashiyama, “Decomposition of Dye in Water Solution by Pulsed Power Discharge in a Water Droplets Spray”, IEEE TRANSACTIONS ON PLASMA SCIENCE, Vol. 36, pp.2586-2591 (2008) [2] Taiki Handa, Yasushi Minamitani, “The Effect of a Water Droplets Spray and Gas Discharge in Water Treatment by Pulsed Power”, IEEE TRANSACTIONS ON PLASMA SCIENCE, Vol. 37, pp.179-183 (2009)
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03P-49: TEM and EDX Analysis of Bacterial Spores Treated by Nanosecond
Pulsed Electric Fields K. Arikawa1, J. Choi1, T. Namihira2,
T. Sakugawa1, S. Katsuki2, H. Akiyama1, H. Seta3, X. Y. Shan3, N. Ando3
1Graduate School of Science and Technology, Kumamoto University, Kumamoto, Japan
2Bioelectrics Research Center, Kumamoto University, Kumamoto, Japan
3Product Development Center, Suntory LTD., Kawasaki, Japan
There have been many attempts to kill spores in liquid by pulsed electric field (PEF) for last half century. However, only a few successful experiment has been reported [1, 2]. In conventional treatment systems, electrical power into the exposure cell, which usually consists of two parallel plane electrodes, is limited by the arcing across the electrodes because of the local vaporization. This paper describes the nanosecond PEF treatment of Bacillus subtilis spores in liquid using a pressurized flow system, which enables to increase the power level to be sufficiently large to kill spores. Also we discuss the killing mechanism based on the microscopic element analysis using a transmission electron microscope (TEM) with an energy dispersive X-ray spectroscopy (EDX). The exposure cell is a conventional parallel electrode with inlet and outlet for the bacterial suspension. The electrode separation and the cell volume are 4 mm and 0.92 ml, respectively. A no-fluctuation compressor and a flow control valve were used to keep the treatment pressure constant. The temperature of the suspension was precisely monitored at the outlet of the exposure cell by using an electrically isolated device based on temperature sensitive fluorescent dye. The pulsed power generator based on a magnetic compression scheme repetitively delivers 100 ns long, 60 kV voltage pulses to the exposure cell. As a result of the PEF application to Bacillus subtilis spores at the pressure of 0.6 MPa, the number density of spores were successfully reduced by 10-5 at the temperature of 110˚C, which is 10˚C lower than that in the heating sterilization process [3]. The result shows that the PEF treatment at high temperature is effective to kill spores. The EDX analysis shows the distribution of elements over the spore that mainly consists of core, cortex layer and coat layer in the order from the center to the outside. The element distribution enables us to deduce how spore could be damaged by PEF treatment. Phosphorus is abundant both in core and in coat but not in cortex. The PEF-treated sample was compared with an untreated one as a sham control and an autoclaved one. In the heat-treated spores, core contents including
phosphorus leak into cortex, which indicates the breakdown of the core membrane, while the coat structure still remains. On the other hand, the PEF treatment damages both the core membrane and coat structure. 1. V.O. Marquez, G.S. Mittal and M.W. Griffiths, J. Food Sci. Vol. 62, No. 2, pp.399-409 (1997) 2. S. Katsuki, et al., IEEE Trans. Plasma Sci. Vol. 28, No. 1, pp.155-159 (2000) 3. J. Choi, et al., J. Appl. Phys. Vol. 104, 094701 (2008)
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03P-50: Shielding Effectiveness of Low Temperature Plasma Screen
S. S. M. Chung1, 2, J. W. Lan1, H. Y. Lin3, S. H. Cheng4, T. W. Suen5
1Department of Electronics Engineering, Southern Taiwan University of Technology,
Tainan, Taiwan 2Center for Micro/Nana Science and Technology, National Cheng Kung University, Tainan, Taiwan 3Mechanical and System Research Laboratory,
Industrial Technology Research Institute, Hsinchu, Taiwan
4Institute of Nuclear Energy Research, Atomic Energy Commission, Taoyuan, Taiwan
5Electronic Research Division, Chung-Shan Institute of Science and Technology, Taoyuan,
Taiwan
Recent advancements in Directed Energy Weapons (DEW) like high power laser and High Power Microwave (HPM) have sprouted interests in technologies for defense against such attack. One option for defending against HPM is plasma shielding. Plasma is a high pass filter with cross over frequency theorized to be the characteristic plasma frequency, which is a function of collision frequency and Electron Energy Distribution Function (EEDF). In practice how to generate and sustain such plasma with high characteristic plasma frequency and minimum power had been the major issue. We manufacture an array of plasma tube 12 mm in diameter and arrange them into screen. The low temperature plasma is generated with low power (300W), ~20 KHz, 10 KV peak voltage signal or DC, 1KW, very high voltage power supply, and the plasma Area Filling Factor (AFF) is about 17-50%. AC generated plasma have higher AFF, while DC generated plasma have higher plasma density due to higher power and plasma concentration on the axis. The plasma screen is placed in front of a strong reflector to test the shielding effect on the reflector’s Radar Cross Section (RCS). Preliminary results indicated the characteristic plasma frequency has a very large transition range of about 2 GHz, and even at 300W, the plasma still can shield 32% of reflected signal at 2-4 GHz range. Cross polarization show better shielding effectiveness. This technology can be used in satellite defense against HPM attack or reducing the RCS of a strong reflector.
03P-51: Parametric Studies of an Electrohydrodynamic Plasma Actuator
for Boundary Layer Flow Control T. Hurtig, P. Appelgren, A. Larsson
Defence & Security Systems and Technology, Swedish Defence Research Agency, Stockholm,
Sweden
An electrohydrodynamic plasma actuator can be used as an aerodynamic flow control device. The plasma actuator can be realised as a surface-mounted dielectric barrier discharge (DBD) that transfers directed energy from ions in the discharge to the surrounding air. Such a plasma actuator acts as a flow control device since one can modify the large scales of an airflow by adding small amounts of momentum to the boundary layer of the flow. A plasma actuator based on the DBD-technique has been designed and built. The plasma actuator consists of two surface-mounted electrodes separated in the direction of the air flow. Only one of the electrodes is in contact with the surrounding air while the other electrode is buried beneath a dielectric layer. The diagnostics consists of current and voltage probes that monitor the electrical characteristics of the actuator together with a hot ball probe that measures the velocity of air flow induced by the plasma actuator. Parametric studies have been performed in order to investigate the relative efficiency in terms of electrical power into the actuator versus mechanical power in the generated boundary flow. The parametric study includes variations of the applied driving voltage and frequency as well as different electrode and dielectric materials. It is found that, within the range tested, the absolute power in the boundary flow increase with increasing electrical power into the actuator. It is also found that, in terms of electrical to mechanical efficiency, an optimum driving frequency exists for each value of applied voltage.
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03P-52: Radiation Hardness of Avalanche Diodes and Gas Discharge Tubes Used
for Transient Voltage Suppression M. Vujisic1, K. Stankovic2, V. Vukic3
1Faculty of Electrical Engineering, University of Belgrade, Belgrade, Serbia
2Institute of Nuclear Sciences, Belgrade, Serbia 3Electrical Engineering Institute, Belgrade, Serbia
The aim of the paper is to investigate the influence of irradiation on transient voltage suppression (TVS) devices, by exposing them to a combined neutron/gamma radiation field. The conducted experimental results show that irradiation of TVS diodes causes a lasting degradation of their protective characteristics, while gas discharge tubes (GDTs) exhibit only a temporary change of performance, reverting to the pre-irradiation state in a matter of hours. Certain aspects of the radiation induced change in GDT performance may even be regarded as an improvement of protective ability. The paper provides theoretical interpretations of the effects observed in the investigated components. Radiation induced changes in TVS diode operation are attributed to the rise of bulk and surface carrier recombination rates, caused by both neutrons and gamma rays. In the case of GDTs, radiation induced changes are mainly due to the effects of the neutron field component, which ultimately lead to a higher concentration of potentially initializing free electrons in the tube's inter-electrode gap.
03P-53: Optimization of Discharge Condition for Recycling Aggregate by Pulsed Discharges Inside of Concrete
D. Wang1, S. Inoue2, J. Araki2, T. Aoki3, S. Maeda2, S. Iizasa2, M. Takaki2, T. Namihira4,
M. Shigeishi2, M. Ohtsu2, H. Akiyama2 1Priority Organization for Innovation and
Excellence, Kumamoto University, Kumamoto, Japan
2Graduate School of Science and Technology, Kumamoto University, Kumamoto, Japan
3Department of Computer Science and Electrical Engineering, Kumamoto University, Kumamoto,
Japan 4Bioelectrics Research Center, Kumamoto
University, Kumamoto, Japan
In Japan, a large amount of waste concrete scraps as industrial wastes becomes a big issue. Currently, the most of waste concrete scraps have been reused as roadbed materials and the recycling ratio of waste concrete scraps has been kept over 95% from 2000. However, it is expected that the demands of waste concrete scraps as roadbed materials would decreases even though the waste concrete scraps increase with the pulling down buildings in next decades. These mean that the recycling of waste concrete scraps would be in the negative situation. In addition, it has been becoming one of the environmental issues that the natural coarse aggregates have been gradually exhausted. Therefore, the development of a new recycling technology of waste concrete scraps has become of paramount importance in Japan. One of the conventional recycling methods to make cement paste free coarse aggregate from waste concrete scraps is based on mechanical stress; consequently it has quality restriction of the reproduced material. Moreover, the applied high stresses result in extensive destruction crashes not only the concrete but also the aggregates. In our studies, a new recycling technology has been presented by using pulsed power discharges inside of waste concrete scraps immersed in water to reproduce the coarse aggregate. In this system, a Marx generator was used as a pulsed power source and a point to hemisphere mesh electrode was immersed in water. The pulsed voltages were applied to the concrete scraps placed on hemisphere mesh and the discharge passes were formed inside of concrete scraps as the result of the electrical breakdown. Immediately after the breakdown, the concrete scraps were broken by the shockwave due to the volumetric thermal expansion of the discharge pass. After the repetitive discharge treatments, the recycled coarse aggregates were evaluated. From our previous results, the quality of the recycled coarse aggregates such as the oven-dry density, the water absorption ratio, and
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the fineness modulus were controlled by the energy consumption of discharge treatments. In the present work, the effects of the electrode gap and the water quality on the quality of recycled aggregate were investigated. Moreover, the quality dependences of recycled aggregates on aggregate brand, such as limestone, andesite and tight sands, and on the concrete compressive strength in the range of 40 to 100 N/mm2 will be discussed at the presentation.
03P-54: Electrohydraulic Shock Wave Generation as a Mean to Increase Intrinsic Permeability of Concrete
T. Reess1, A. De Ferron1, O. Maurel2, W. Chen2, M. Matallah2, C. Laborderie2, G. Pijaudier2, F. Rey-bethbeder3, A. Jacques3, J. Lassus3
1Laboratoire de Genie Electrique, University of Pau, Pau, France
2IPRA, University of Pau, Pau, France 3TOTAL, Pau, France
The subject of this article is to present an experimental study of Pulsed Arc Electrohydraulic Discharges (PAED) in water. The aim is to produce dynamic shock waves in order to increase the intrinsic permeability of mortar specimens which are immersed in water. The experimental set up allows the switching of high pulsed energy up to 100kJ in order to develop high amplitude shock waves in water. Two stainless steel ovoid electrodes are immersed in a glass fibre tank filled with tap water. The gap between the two electrodes is D=10mm. A triggered air-gap-switch is installed to discharge a tank capacitors into the water gap. The temporal behaviour of the pressure is measured using piezoelectric PVDF sensors, which present a high natural frequency of 100MHz. A relationship between the peak pressure, the energy remaining at breakdown time and the distance from the channel discharge to the mortar specimen allows the control of the peak pressure applied to cylindrical mortar specimens. The maximum applied pressure is 250MPa. The evolution of damage due to dynamic mechanical loads is correlated with the intrinsic permeability of the mortar. The behaviour of the intrinsic permeability versus applied dynamic pressure is studied in single shock. A threshold of pressure is highlighted. Indeed, no modification of the intrinsic permeability is measured for dynamic pressure level lower than 90MPa. From this value, the permeability increases linearly on a log-log plot. The influence of shock number on permeability is also presented for a constant applied pressure of 90MPa.
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03P-55: Breakdown Characteristics of Argon in Partial Vacuum under High
Frequency Pulsed Voltage with Varying Duty Cycle
M. Lipham, H. Zhao, S. Li, H. Kirkici Electrical and Computer Engineering, Auburn
University, Auburn, AL, United States
Power devices and systems operating in partial vacuum are susceptible to partial discharges, corona, or volume discharge [1]. In most cases, it is important to understand the characteristics of the discharge such as the space-charge distribution, the electron energy distribution, and collision processes in which the species are involved. Breakdown and spectroscopic studies of the discharge are the most commonly used methods of obtaining such information [2]. In this paper, the breakdown characteristics for Argon are studied in partial vacuum of 100 milliTorr to 5 Torr. A unipolar pulsed signal is applied to the parallel plate and point-plane electrode configuration [3]. The frequency is varied from 10 kHz to 100 kHz with varying duty cycle from 10% to 90%. Current- voltage and optical spectroscopic data of the argon discharge, collected as a function of time, is presented. The spectra of the light emission is time resolved with a 1ms time resolution and consecutive frames. From this series of data, the time variation of the intensities for dominant lines in the spectra lines are studied. The results of the analysis help to understand the collision processes involved in the plasma formation for the pulsed breakdown at kHz frequencies. 1. K. Koppisetty, H. Kirkici, D.L. Schweickart, “Partial vacuum breakdown characteristics of helium at 20 kHz for inhomogeneous field gap”, IEEE Transactions on Dielectrics and Electrical Insulation, Volume 14, June 2007 Page(s):553 -559 2. K. Koppisetty, M. Serkan, H. Kirkici, “Image Analysis: A Tool for Optical-Emission Characterization of Partial-Vacuum Breakdown”, IEEE Transactions on Plasma Science, Volume 37, Page(s):153 – 158, Jan. 2009 3. K. Koppisetty, H. Kirkici, “Breakdown characteristics of helium and nitrogen at kHz frequency range in partial vacuum for point-to-point electrode configuration”, IEEE Transactions on Dielectrics and Electrical Insulation, Volume 15, Page(s):749 – 755, June 2008
03P-56: Improvement of Polyphenols Extraction from Grape Pomace Using
Pulsed Arc Electro-Hydraulic Discharges N. Boussetta1, A. Silvestre de Ferron2, T. Reess2,
L. Pecastaing2, J. L. Lanoiselle1, E. Vorobiev1 1Université Technologique de Compiègne, Unité
de Transformations intégrées de la Matière Renouvelable, Compiègne, France
2Université de Pau, Laboratoire de Génie Electrique, Pau, France
Recently, the use of pulsed power has been studied for extraction of soluble compounds from bio products. This work aims at producing high dynamic shock waves by Pulsed Arc Electro-hydraulic Discharges (PAED) in a water based mixture in order to increase polyphenols extraction from grape pomace. Grape pomace is winemaking by-products composed of skins, seeds and stems. They contained valuable compounds like polyphenols. These molecules have attracted interest for their antioxidant activity. A triggered air-gap switch is used to discharge capacitors into the mixture containing grape pomace and water. The gap switch breakdown (40kV maximum pulse voltage) produces a high dynamic shock wave in the liquid. The energies are set to 160J and 4kJ with a pulse repetition frequency of 0.5Hz. Two discharge chambers of 1L and 35L are used. They are made from a stainless steel cylindrical vessel and contain a point to plane gap of 10mm. Grape pomace is firstly treated by PAED in water with a liquid/solid ratio equal to 5 and then introduced in a diffusion cell under agitation. The contents of total solutes and total polyphenols of extracts are obtained by the values of degree Brix and absorbance at 280 nm respectively. Results point out the increase of total solutes and polyphenols extraction from grape pomace after PAED treatments. Nevertheless, the scale extrapolation study requires to maintain constant the ratio of energy to product mass (in our case, it was equal to 0.53). For example, a treatment at the laboratory scale of 100 pulses at 160J/pulse gives similar results as a treatment at the pilot scale with 300 pulses at 4000J/pulses. In these conditions, the content of polyphenols is 6-fold higher (300mg/l) and the degree Brix is increased by 1.5 after PAED application.
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03P-57: Fruit Body Formation of Basidiomycete by Pulse Electric Field
Stimulations K. Takaki1, N. Yamazaki1, S. Mukaigawa1, T. Fujiwara1, H. Kofujita2, Y. Sakamoto3, K. Takahasi4, M. Narimatsu5, K. Nagane6 1Faculty of Engineering, Iwate University,
Morioka, Iwate, Japan 2Faculty of Agriculture, Iwate University, Morioka,
Iwate, Japan 3Microorganism Application Research
Department, Iwate Biotechnology Research Center, Kitakami, Iwate, Japan
4Morioka Forest Association, Morioka, Iwate, Japan
5Tono Agricultural and Forestry Center, Tono, Iwate, Japan
6Nagane Co. Ltd., Kunohe, Iwate, Japan
Pulsed high voltage was applied to logs for mushroom culturing to clarify an effect of the pulse voltage stimulation on fruit body formation of basidiomycetes i.e. mushroom. Inductive energy storage system was employed to construct a pulsed power generator with compact size. Copper thin fuse was used as opening switch to interrupt large circuit current in short time. The fuse had the dimension of 0.05 mm diameter and 10 cm length. Four stages Marx generator was used to supply a large current to a secondary energy storage inductor. The output voltage of the inductive energy storage system pulsed power generator was 120 kV with 50 ns pulse width at 5 kV charging voltage to the primary energy storage capacitor. The output voltage of 50 ns pulse width was applied to sawdust-based substrate of Lyophyllum decastes, Ganoderma lucidum, and natural logs of Lentinula edodes, Pholiota nameko and Naematoloma sublateritium as an electrical stimulation. The experimental results clearly showed that the fruit body formation for some kinds of mushroom was improved to be 1.5-2.1 times larger total weight of the formed fruit body by applying pulse voltage as electrical stimulation. For Lentinula edodes, the total weight cropped by fifteen logs was 2.29 kg at fifty times 50 kV pulse voltage stimulations. The weight of 2.29 kg was larger than 1.09 kg at one 50 kV pulse stimulation case. The maximum vale of the cropped fruit body weight by one log was 300 g at one time pulse stimulation, the weight 300 g was similar value with 320 g at fifty times stimulation case. However, there were no logs without the fruit body formation at fifty times stimulation case, whereas the fruit body was not formed on seven logs at one-time stimulation case. These results indicate clearly that the pulse voltage is effective as stimulation for fruit body formation of the some kinds of basidiomycete.
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03P-58: Effects of Nanosecond Pulsed Electric Field on the Embryonic
Development of Medaka Fish Egg (Oryzias Latipes)
D. K. Kang1, S. Nakamitsu1, S. Iwasaki1, S. H. R. Hosseini1, S. Kono2, N. Tominaga2,
T. Sakugawa1, S. Katsuki1, H. Akiyama1 1Graduate School of Science and Technology,
Kumamoto University, Kumamoto, Japan 2Ariake National College of Technology, Omuta,
Japan
The paper describes the effects of 50 to 300 nanosecond pulsed electric field on the embryonic development of the medaka fish egg (Oryzias latipes). In the recent years it has been reported that applying short (less than 100 ns) pulses increased the possibility of electric field interactions with subcellular structures, which leaded to secondary cellular events, such as temporal increase in cell membrane permeability and induction of apoptosis. The goal of the current study was to find the effects of short pulsed electric field in-vivo and during embryo development. A pulsed power modulator using a magnetic compression circuit was employed to generate 0.5 to 20 kV pulses with 50 to 300 nanosecond pulse durations. Input voltage and current were measured by using an oscilloscope and a current monitor. Fertilized eggs of d-rR medaka were used. The age of the experimental eggs were 6 hours, 1 day and 2 days post fertilization. In each experiment, a single medaka egg (about 1.2 mm diameter) was set at the middle of a 2 mm or 4 mm cuvette and a single electric pulse was applied. After the experiments the eggs were observed under a microscope until they hatched or died. A fluorescent plasma membrane integrity indicator, propidium iodide (PI), was used to study electroporative uptake kinetics of the embryo cells after the electric pulse exposure. By applying 300 ns electric pulses, extensive damage of eggs were observed immediately after pulse application. For shorter 50 ns width pulses and low electric field, delayed hatching consistent with electric field subcellular interaction was observed, whereas stronger electric field affected the eggs immediately after the pulse and those eggs could not survive and died a few days later.
03P-59: Operation of an Electroporation Device for Mash
M. Sack1, J. Sigler2, C. Eing1, L. Stukenbrock2, R. Staengle1, A. Wolf1, G. Mueller1
1Forschungszentrum Karlsruhe, Eggenstein-Leopoldshafen, Germany
2Staatliches Weinbauinstitut, Freiburg, Germany
In the course of the production of red wine the electroporation of mash enables a fast extraction of the red pigments from the skin without remarkable heating of the mash. For white wine the formation of pores in the cells fosters among others the extraction of flavouring substances. To demonstrate and further investigate these advantages the mobile electroporation device KEA-WEIN has been built. After a refurbishment in 2007, during the harvest 2008 the electroporation device KEA-WEIN has been operated successfully in two wineries. All together more than 5m of mash has been treated. The electroporation device KEA-WEIN is equipped with a 6-stage Marx-Generator operating at a repetition rate of up to 20 Hz. For the pulse application the mash is pumped through an electroporation reactor with a homogeneous field distribution. It was the aim of this years experiments to gain some experience in the operation of the electroporation device on-site in a winery. To facilitate the evaluation of the experimental results, the electroporation device has been equipped with different sensors and measurement systems, e.g. for the power drawn from the grid, the temperature of the mash before and after the electroporation, and the throughput. A computer interface enables a continuous data logging. The paper presents and discusses the measurement results and experience gained during operation.
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03P-60: Promotion of Germination Usng Pulsed Electric Field
S. Ihara, R. Inuzuka, C. Yamabe Department of Electrical and Electronic
Engineering, Faculty of Science and Engineering, Saga University, Saga, Japan
In this research promotion of plant germination by electric stimulation were demonstrated experimentally. Gladiolus, which is a genus of flowing plants in the iris family (Iridaceae) and bulbous plant, was selected as a subject because it is easy to cultivate. 32 bulbs were prepared for specimens, and 16 specimens were stimulated by applying pulsed voltage, which has a pulse width of 100 ns and a peak value of 23 kV using pulsed power. Specimens were put into electrodes at the stimulation. Needle and plate were used as high voltage and grounded electrodes, respectively. When the voltage was applied the specimen and the electrodes were immersed into water to avoid electric discharge across the electrodes. The Bulbs were cultivated for 3 month after applying voltage, and changing of the plant height was measured for culturing. The stimulated and non-stimulated bulbs started to germ at about 3 weeks and 4 weeks after, respectively. The experimental results showed that the electrical stimulation promoted the germination of the plant.
03P-61: Isolated Power Supply for Self-Neutralization Tests of a Ferroelectric
Plasma Thruster B. T. Hutsel, S. D. Kovaleski, J. W. Kwon
Dept. of Electrical and Computer Engineering, University of Missouri, Columbia, MO, United
States
The ferroelectric plasma thruster (FEPT) is being developed for use in micro-spacecraft propulsion, large scale structure vibration damping, and proximity operations. An advantage of the FEPT over other thruster technologies, such as colloid and field emission electric propulsion (FEEP) thrusters, is that the FEPT operates with a single power supply [1]. Additionally it is believed that the FEPT is self-neutralizing since both electrons and ions are accelerated to produce thrust [2]. In order to test the self-neutralization capabilities of the FEPT, the FEPT must be operated with a power supply that is isolated from the ground of the vacuum chamber wall. Presented is the design of an isolated power supply to test the self-neutralization of the FEPT operating in a vacuum chamber. [1] M. A. Kemp and S. D. Kovaleski, “Ferroelectric plasma thruster for microspacecraft propulsion,” J. Appl. Phys., vol. 100, no. 1, p. 113 306, Dec. 2006. [2] S. D. Kovaleski, “Ion acceleration in a radio-frequency driven ferroelectric source,” IEEE Trans. Plasma Sci., vol. 33, no. 2, pp. 876–881, Apr. 2005.
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03P-62: Flashover Prevention of High Voltage Piezoelectric Transformers A. Benwell, S. D. Kovaleski, J. W. Kwon,
T. Wacharasindhu, E. Baxter Electrical and Computer Engineering, University of Missouri - Columbia, Columbia, MO, United
States
Piezoelectric transformers are used as step up voltage elements in many devices [1, 2]. The University of Missouri is developing a piezoelectric transformer as an accelerator for an ion beam [3]. In cases where high voltage pulses are desired, discharges can result from a large electric field near triple point junctions [4, 5]. Due to the small scale of the device, conductive triple point shields are difficult to employ to prevent flashover. This paper presents an investigation of piezoelectric flashover prevention by thin film encapsulation and by dielectric strength matching. Dielectric material was deposited on the piezoelectric transformer both over the entire device, and at specific regions of interest. The dielectric was deposited by evaporation to eliminate gaps at the triple point. The flashover strength is evaluated depending on the dielectric type, thickness, and length. The mechanical loss incurred by the deposition is evaluated to determine if it hinders the motion of the transformer. References [1] Y. Wang, J. He, Y. Liu, J. Wu, C. Lee, and Y. Haung, Theory and experiment of high voltage step-up ratio disk type piezoelectric transformer for lcd-tv, July 2005, pp. 284-287. [2] J. Yang, Piezoelectric transformer structural modeling - a review, Ultrasonics, Ferroelectrics and Frequency Control, IEEE Transactions on, vol. 54, no. 6, pp. 1154-1170, 2007. [3] A. Benwell, S. Kovaleski, M. Kemp, A high-voltage piezoelectric transformer for active interrogation, Journal of Nuclear Materials Management, vol. 37, p. 42, 2008. [4] K. Nakamura and Y. Adachi, Piezoelectric transformers using linbo3 single crystals, Electronics and Communications in Japan, vol. 81, no. 7, pp. 1-6, 1998. [5] H. Itoh, K. Teranishi, and S. Suzuki, Discharge plasmas generated by piezoelectric transformers and their applications, Plasma Sources Science and Technology, vol. 15, no. 2, pp. S51-S61, 2006.
03P-63: Spectral Diagnosis of Plasma Jet at Atmospheric Pressure
X. L. Tang1, 2, 3, G. Qiu1, 2, 3, X. Wang4, X. P. Feng4
1Plasma & Surface Research Center, College of Science, Donghua University, Shanghai 201620,
China 2National Engineering Research Center for Dyeing and Finishing of Textiles, Shanghai
201620, China 3College of Material Science and Engineering, Donghua University, Shanghai 201620, China 4Department of Physics, University of Puerto
Rico, San Juan, P. R. 00931-3343, Puerto Rico
A new approach to surface modification of materials using dielectric barrier discharge (DBD) plasma jet at atmospheric pressure is presented in this paper. The emission spectral lines of argon plasma jet at atmospheric pressure were recorded by the grating spectrograph HR2000 and computer software. The argon plasma emission spectra, whose range is from 300nm to 1000nm, were measured at different applied voltage. Comparing to air plasma emission spectra under the same circumstance, it is shown that all of the spectral lines are attributed to neutral argon atoms. The spectral line 763.51mn and 772.42nm are chosen to estimate the electron excitation temperature. The purpose of the study is to research the relationship between the applied voltage and temperature to control the process of materials’ surface modification promptly. The results show that electron excitation temperature is in the range of 0.1eV-0.5eV and it increases with increasing applied voltage. In the process of surface modification under the plasma jet, the infrared radiation thermometer was used to measure the material surface temperature under the plasma jet. The results show that the material surface temperature is in the range of 50～100 degrees centigrade and it also increases with increasing applied voltage. Because the material surface was under the plasma jet and its temperature was decided by the plasma, the material surface temperature increases with increasing the macro-temperature of plasma jet，the relationship of the surface temperature and applied voltage indicates the relationship of the macro-temperature of the plasma jet and the applied voltage approximately. The experimental results indicate that DBD plasma jet at atmospheric pressure is a new approach to improve the quality of materials’ surface modification, and spectral diagnose is proved to be a kind of workable method by choosing suitable applied voltage.
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03P-64: The Effects of Collection Plate Area with Electrostatic Flows Resulting
from Multiple Corona Discharges J. D. Kribs, M. S. June, K. M. Lyons
Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC, United
States
To initiate an electrostatic flow within atmospheric air, the high voltages are applied to the atmosphere by the coronas, creating an ionic flow to a grounded collection plate or ring. In experiments with a focus on the viability of applying the ionic wind as a cooling mechanism, using a short annulus as the grounded collection plate for the corona discharges, it was found that there is a relationship between the size of the grounded ring and the velocity of the flow caused by the corona discharge, finding that maintaining voltage as a constant, a smaller ring provides higher efficiencies, while larger rings provide high flow rates at larger static pressures. Further research is being conducted on the influence of multiple corona discharges on the velocity and the effective static pressure of ionic flows in air as well as combustible flows
03P-65: Toxicity of Direct Non-Thermal Atmospheric Pressure Plasma Treatment
of Living Tissue S. Kalghatgi1, D. Dobrynin2, A. Wu3,
E. Podolsky3, E. Cerchar3, G. Fridman4, A. Fridman2, A. Brooks3, K. Barbee4,
G. Friedman1 1Department of Electrical and Computer
Engineering, Drexel University, Philadelphia, United States
2Department of Mechanical Engineering, Drexel University, Philadelphia, United States
3Department of Surgery, Drexel University College of Medicine, Philadelphia, United States
4School of Biomedical Engineering, Drexel University, Philadelphia, United States
Introduction Non-thermal dielectric barrier discharge plasma produced at normal atmospheric pressure and applied directly to living tissues is now being widely considered for various applications in medicine, viz; skin sterilization, wound treatment, treatment in malignant tissues and many others. One of the key questions that arises in this type of topical treatment is if the skin remains undamaged after non-thermal plasma treatment. In this paper we study the possible short term and long term toxic effects of the non-thermal plasma treatment on intact living tissue. Non-thermal plasma has been shown to sterilize intact tissue without visible or microscopic damage, and our goal was to identify the boundaries of skin toxicity after treatment. Methods The results from the previous rodent model provided strong evidence for the ability of non-thermal plasma to sterilize the surface of the tissue without any visible or microscopic damage to the tissue. It is well established that porcine (pig) skin closely resembles human skin; hence we evaluated the potential toxic effects of non-thermal plasma treatment on underlying skin cells and tissue on intact porcine skin. We evaluated the potential toxic effects on intact porcine skin in two Yorkshire pigs whose dorsal surfaces were divided into 36 treatment areas, 3 untreated and 1 treated with an electrocautery burn (positive control). The remaining 32 areas were treated with 1 of 4 power settings: Highest power 1.0 Watt/cm^2 (n=2), 0.75 Watt/cm^2 (n=2), 0.50 Watt/cm^2 (n=2), and lowest power 0.25 Watt/cm^2 (n=26). Treatment at low power was either for 30 seconds, 2, 5, or 15 minutes. All other powers were treated for 3 minutes and observed at 1 minute intervals. We assessed skin and wound damage grossly and harvested each specimen for histological analysis immediately and 24 hours post treatment. Results Low power treatment up to 15 minutes caused no
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gross, microscopic, or histological tissue damage, while 3 minutes at highest power damaged the epidermis and dermis. The first sign of gross change (erythema) occurred after 1 minute treatment at 0.50 Watt/cm^2. Damage through to the dermis was first seen after 3 minutes at 0.75 Watt/cm^2. Of note is that sterilization is achieved in about 5 sec at a low power treatment of 0.2 Watt/cm^2. Conclusions Low power plasma treatment is non-toxic to intact pig skin. The earliest signs of tissue damage occur at 0.50 Watt/cm2. Detailed analysis of any biochemical changes and inflammatory response initiation in the treated tissue will be carried out. Low power plasma treatment is now being evaluated as a safe method for sterilization of living tissue.
03P-66: Experimental Investigations of Ring-Shaped Plasma Bullets Emitted by a
Pulsed Plasma Jet M. Laroussi, E. Karakas, A. Begum
Laser & Plasma Engineering Institute, Old Dominion University, Norfolk, VA, United States
Non-thermal atmospheric pressure plasma jets have recently been playing an increasingly important role in plasma processing [1]. These devices are able to provide plasma plumes /jets in ambient air and not confined by electrodes. In this paper we report experimental investigations on the characteristics of the plasma jet emitted by a pulsed plasma source, the Plasma Pencil. The plasma pencil is driven by a high voltage pulses (up to 10 kV) with variable pulse widths (from nanoseconds to milliseconds) and repetition rates (up to 10 kHz). Using ICCD images we show that the plume is a series of plasma packets/bullets traveling at supersonic velocities. The plasma bullet phenomenon was first observed by Teschke and co-workers for an RF jet (2005) and Laroussi and co-workers in the case of a nanoseconds pulsed jet (2006) [1]. The ICCD images revealed that the plasma bullets are hollow and assume a ring (or donut) shape. Based on these observations we propose that surface ionization waves are behind the formation and propagation of the plasma bullets. Along with these results we also show that the applied voltage magnitude, the pulse length, and the gas flow rate are the major parameters affecting the characteristics of the plume/jet. [1] M. Laroussi and T. Akan, Arc-free Atmospheric Pressure Cold Plasma Jets: A Review, Plasma Processes and Polymers, Vol. 4, pp. 777-788, 2007.
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03P-67: On the Interaction of Non-Thermal Atmospheric Pressure Plasma
with Tissues S. Kalghatgi1, C. Kelly2, E. Cerchar3,
R. Sensenig3, A. Brooks3, A. Fridman4, A. Morss-Clyne4, J. Azizkhan-Clifford2, G. Friedman1
1Department of Electrical and Computer Engineering, Drexel University, Philadelphia,
United States 2Department of Biochemistry and Molecular
Biology, Drexel University College of Medicine, Philadelphia, United States
3Department of Surgery, Drexel University College of Medicine, Philadelphia, United States 4Department of Mechanical Engineering, Drexel
University, Philadelphia, United States
Non-thermal atmospheric pressure plasma is now being widely developed for various medical applications such as skin sterilization, blood coagulation, apoptosis, angiogenesis and wound healing among others. However, understanding of mechanism of interaction between non-thermal plasma and mammalian cells is lacking. Here we investigated the possibility that the dose of non-thermal plasma can be tuned to achieve various results depending on the clinical applications ranging from enhanced cell proliferation to inducing apoptosis in malignant tissue. We also attempt to determine the underlying mechanisms of interaction of non-thermal plasma with mammalian cells. First we studied the possibility that the effects of plasma could penetrate the cell membrane without damaging it. One of the most significant of such effects could be DNA damage since this is most threatening to cell survival. We measured DNA damage in mammalian cells using immunofluorescence and western blots to detect phosphorylation of the histone protein H2AX (γ-H2AX), which is a marker of DNA damage. The results indicate that short (5 seconds) direct plasma treatment at low power (0.13 W/cm^2) produces DNA damage in mammalian cells, suggesting that somehow the effects of plasma penetrate the cells. The level of damage is dependent on the dose of plasma treatment and at low doses (5 J/cm^2), cells undergo apoptosis. Further, cells treated with plasma at a dose of 0.2 J/cm^2 demonstrated twice as much proliferation as untreated cells. FGF2 release increased up to 3 h after plasma treatment, and the cell proliferative response to plasma treatment was negated by an FGF2 blocking antibody. Reactive oxygen species generated by non-thermal plasma in liquid may mediate release of FGF2 from cells after plasma treatment, since the effects were blocked with N-acetyl cysteine (NAC), a free radical scavenger. At doses higher than 1 J/cm^2 annexin-V/PI staining revealed a significant increase in apoptosis in plasma-
treated cells at 24, 48, and 72 hours post-treatment. Caspase-3 cleavage was observed beginning at 48 hours post plasma treatment at a dose of 5 seconds (5 J/cm^2). Pretreatment of cells with NAC, significantly decreased apoptosis in plasma-treated cells. We demonstrate that non-thermal plasma interacts with cells indirectly by producing long living organic peroxides in the cell growth medium, which can mediate the effects of plasma on cellular DNA. Low dose of non-thermal plasma treatment enhances cell proliferation through FGF2 release which is blocked by ROS scavengers. Plasma treatment induces apoptosis in through a pathway that appears to be dependent on DNA damage induced by plasma produced ROS. Non-thermal atmospheric plasma discharge (Plasma) may provide a novel approach to induction of apoptosis in cancer cells. Thus non-thermal plasma can be tuned to achieve various results from enhanced proliferation, stimulation of angiogenesis to induction of programmed cell death in malignant tissue.
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04P: Pulsed Power Sources, Pulsed Power Systems, Diagnostics, and Power Electronics & Systems
East/State
Thursday, July 2 13:30-14:45
04P-1: Beam Loading in the Darht Second Axis Induction Cells
K. Nielsen1, D. Dalmas1, J. Johnson1, R. Temple1, B. Prichard2, C. Y. Tom3
1Hydrodynamic Experiments, Los Alamos National Lab, Los Alamos, NM, United States
2SAIC, Los Alamos, NM, United States 3NSTEC, Los Alamos, NM, United States
The Dual-Axis Radiographic Hydrodynamics Test (DARHT) facility employs two perpendicular electron Linear Induction Accelerators to produce intense bremsstrahlung x-ray pulses for flash radiography. The second axis, DARHT II, features a 2.5-MeV injector and a 15.5-MeV, 2-kA, 1.6-microsecond accelerator consisting of 74 induction cells and drivers. Major induction cell components include high flux swing magnetic material (Metglas 2605SC) and a MycalexTM insulator. The cell drivers are pulse forming networks (PFNs). The cells and drivers are now used with a 2-kA beam and the cell voltage is near 30 kV lower than the drive voltage because of beam loading. Voltage and current waveforms as well as circuit analysis will be used to demonstrate and explain the loading effect and why it is important.
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04P-2: Modulate the Pulse Shape by Varying Volt-Second Products in LTD
L. Zhou, J. Deng, L. Chen, W. Zou Institue of Fluid Physics, CAEP, Sichuan, China
Function of magnetic core in LTD is introduced. The influence of the magnetic cores volt-second product on the output parameters of LTD is deduced by means of simulation. A series of experiments were designed to evaluate the saturation of the magnetic core and the influence on the output parameters of a LTD stage. These experiments were carried out under such conditions as different volt-second product of the core, different reset state of the core and different load resistance. Conclusions as the criterion of magnetic core saturation and reset effects of reverse current to magnetic core were drawn from the experiment results. The experiment results validate the simulation. Application of the saturation effect of magnetic core to specific fields was suggested. Conceptual design of a LTD accelerator was presented based on the deduced conclusions.
04P-3: Comparison of the Performance of the Upgraded Z with Circuit Predictions K. W. Struve1, L. F. Bennett1, J. P. Davis1, D. Hinshelwood2, M. E. Savage1, B. S. Stoltzfus1,
T. C. Wagoner3 1Pulsed Power Sciences Center, Sandia National
Laboratories, Albuquerque, NM, United States 2Plasma Physics Division, Naval Research Laboratory, Washington, DC, United States
3Pulsed Power Department, Ktech Corporation, Albuquerque, NM, United States
Since the completion of the ZR upgrade of the Z accelerator at the Sandia National Laboratories[1] in the fall of 2007, many shots have been taken on the accelerator, and there has been much opportunity to compare initial projections of the performance of the machine with actual measurements. We therefore compare predictions with measured performance for several shot configurations, and present a full-circuit, 36-line Bertha circuit model of the machine. This is done for both short-pulse and long-pulse (tailored pulse) modes of operation. As part of this we also present the as-built circuit parameters of the machine and compare with those anticipated before construction. We also compare the measured forward-going voltage of the machine with predictions that were based on measurements on the Z20 single-module test facility. Furthermore, we discuss enhancements to the circuit model that include 2D and 3D effects in the water lines and MITLs. Finally, we provide equivalent circuit models that fairly accurately represent machine performance. [1] Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.
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04P-4: ZR-Convolute Analysis and Modeling: Plasma Evolution and
Dynamics Leading to Current Losses D. V. Rose1, D. R. Welch1, R. E. Clark1,
E. A. Madrid1, C. L. Miller1, C. B. Mostrom1, W. A. Stygar2, B. M. Jones2, K. W. Struve2,
M. E. Cuneo2 1Voss Scientific, LLC, Albuquerque, NM, United
States 2Sandia National Laboratories, Albuquerque, NM,
United States
Post-hole convolutes are used in high-power transmission line systems and join several individual transmission lines in parallel, transferring the combined currents to a single transmission line attached to a load. Magnetic insulation of electron flow, established upstream of the convolute region, is lost at the convolute due, in part, to the formation of magnetic nulls, resulting in current losses. At very high-power operating levels, the formation of electrode plasmas is considered likely which can lead to additional losses. A recent computational analysis of the Sandia Z accelerator suggested that modest plasma desorption rates in the convolute region could explain measured current losses [D. V. Rose, et al., Phys. Rev. ST-AB 11, 060401 (2008)]. The recently completed Sandia ZR accelerator has utilized new convolute designs to accommodate changes to the parallel-plate transmission lines on ZR. Detailed particle-in-cell simulations, that include plasma desorption from electrode surfaces in the post-hole convolutes, are carried out to assess the measured current losses on ZR. The simulations are being used to access newer convolute designs with the goal of reducing the current losses, particularly for higher-impedance loads.
04P-5: Current Loss in the Vacuum Section of the Refurbished Z Accelerator
T. D. Pointon, D. B. Seidel Sandia National Laboratories*, NM, United States The refurbishment of the Z accelerator at Sandia National Laboratories was completed in September 2007. The vacuum section is topologically similar to the original Z design, but with new hardware for the insulator stack, the four magnetically insulated transmission lines (MITLs), and the double post-hole convolute [1]. For a given load, the operating voltage in the new vacuum section is ~30% higher, and larger current losses in the convolute are observed. The current loss in the vacuum section consists of two parts. Early in time, electrons flowing into the convolute from the MITLs and lost to the convolute anode surfaces account for the current loss. Late in time, the observed current loss is much higher than vacuum electron flow losses predicted by 2-D and 3-D particle-in-cell (PIC) simulations [2]. This additional loss is attributed to dense plasma effects in the convolute. This loss could be due to cathode plasmas [3], anode plasmas formed by deposition heating of the anode, or a combination of the two. There are no detailed diagnostics for guidance, so PIC simulations currently provide the only insight into the source of the additional convolute current loss. We believe that anode plasmas created at magnetic null regions of the convolute play a significant role. To accurately compute the time at which anode plasmas form due to electron deposition heating, accurate modeling of the electron flow into the convolute is required. We use high-resolution 2-D PIC simulations of the exact MITL geometry out to large radius to compute this flow. 3-D simulations of the convolute necessarily use coarser resolution, but with modified MITL geometry reproducing the 2-D flow into the convolute [2]. We have simulated a range of Z shots with time-accurate drive voltage and load impedance. The goal is to characterize the time for the onset of anode plasma formation as a function of MITL current and voltage, as a first step towards creating more realistic models of convolute current loss for use in circuit codes. We are also developing new methods to model dense electrode plasmas in our PIC simulations. Results of this work will be presented. 1. M. E. Savage, et al., 16th International Pulsed Power Conference, Albuquerque NM, June 2007, pp. 979 - 984. 2. T. D. Pointon, et al., 16th International Pulsed Power Conference, Albuquerque NM, June 2007, pp. 165 - 170. 3. D. V. Rose, et al., Phys. Rev. ST Accel. Beams, vol. 11, p. 060401-1, 2008. ________________________________ * Sandia is a multiprogram laboratory operated
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by Sandia Corporation, a Lockheed Martin company, for the United States Department of Energy under contract DE-AC-94-AL85000.
04P-6: An Optimization Study of Stripline Loads for Isentropic Compression
Experiments D. B. Seidel, W. L. Langston, M. D. Knudson,
R. W. Lemke, J.P.Davis, T. D. Pointon Sandia National Laboratories*, Albuquerque, NM,
United States
The Z accelerator at Sandia is a unique platform to study matter under extreme conditions [1]. In its shaped pulse mode, it can deliver up to 20 megaamperes of current to an inductive load over ~600 nanoseconds. The high current and corresponding multi-megagauss magnetic field enable quasi-isentropic compression experiments to stresses of several megabars. A recent innovation in this area has been the use of a stripline, rather than coaxial, load configuration. This configuration allows higher magnetic fields at sample surfaces than a coaxial configuration for the same driver current. Also, the magnetic fields on the anode and cathode surfaces are inherently balanced. However, there are new issues that arise with the introduction of such loads. The coaxial configuration is a closed system in the sense that all the magnetic flux is contained between the electrodes. In contrast, the flux in the stripline configuration is not contained between the electrodes, but in fact loops around the outside of each electrode. This, combined with constraints associated with the striplines termination and connection to the driver, necessarily introduces an axial variation (in the direction of the current flow) in the magnetic field of the stripline. In addition, the transverse cross-section of the stripline has a significant effect upon the amplitude of the magnetic field between the striplines electrodes for a fixed drive current, as well as the transverse uniformity of the magnetic field within the stripline. In this paper, we will describe the electromagnetic modeling of various stripline configurations, as well as our efforts to optimize the striplines geometric configuration to maximize both the magnetic field strength available for compression (for a fixed current) and the uniformity of that field. This will include a discussion of the effects of constraints dictated by other aspects of the experiment, and the tradeoffs that must be considered in the optimization process. 1. Marcus D. Knudson, Use of the Z Accelerator for Isentropic and Shock Compression Studies, in Shockwave Science and Technology Reference Library, Vol. 2, Y. Horie, Ed., Ch. 1, Springer Berlin Heidelberg , 2007. * Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energys National Nuclear Security Administration under Contract DE-AC04-94AL85000.
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04P-7: Numerical Simulations of Power Flow in Magnetically Insulated
Transmission Lines Driving Z-Pinch Loads
S. W. Vickers1, J. Chittenden2 1United Kingdom, AWE, Aldermaston, United
Kingdom 2Plasma Physics, Imperial College, London,
United Kingdom
The Z-accelerator [1] at Sandia National Laboratories employs a double-post-hole convolute to couple four magnetically insulated transmission lines (MITLs), in parallel to a single MITL to drive a dynamic Z-pinch load. Detailed magneto-hydrodynamic (MHD) models of the Z-pinch loads are sensitive to current losses in this region of the machine, limiting their predictive capability. A model is presented to investigate the current loss mechanisms, focussing on loss of magnetic insulation in the electron flow [2] and electrode plasma expansion [3]. To minimise computational demands, a hybrid approach has been employed; plasmas formed on the metal feed surfaces are treated as MHD fluids, whilst the kinetic electron flow is modelled using Particle-in-Cell (PiC) techniques. To this end, particle push algorithms have been incorporated into the 3D resistive MHD code, Gorgon [4]. The model is developed on the Z inner MITL electrode geometry [5]. Modelling the Z-pinch load as an imploding liner, and allowing plasma to expand from the cathode and anode surfaces, results for electron trajectories through the resultant electric and magnetic fields are presented. References [1] R. B. Spielman et al., Phys. Plasmas 5, 2105 (1998). [2] T. D. Pointon, W. A. Stygar, R. B. Spielman, H. C. Ives, and K. W. Struve, Phys. Plasmas 13, 043105 (2006). [3] D. V. Rose, D. R. Welch, T. P. Hughes, and R. E. Clark, Phys. Rev. ST Accel. Beams 11, 060401 (2008). [4] A. Ciardi et al., Phys. Plasmas 14, 056501 (2007). [5] W. Stygar et al., Phys. Rev. E 69, 046403 (2004)
04P-8: Conversion of Mercury (a 2-TW Inductive Voltage Adder) to Positive
Polarity* R. J. Allen1, C. L. Berry2, R. J. Commisso1,
E. Featherstone2, R. Fisher2, G. Cooperstein1, D. Hinshelwood1, S. L. Jackson3, A. T. Miller2,
P. F. Ottinger1, D. G. Phipps1, J. W. Schumer1 1Plasma Physics Division, Naval Research Laboratory, Washington, DC, United States
2Titan Group, L-3 Communications, Reston, VA, United States
3National Research Council, Washington, DC, United States
After 616 shots in a negative polarity configuration, Mercury, a 6-MV and 300-kA inductive voltage adder (IVA), has been converted to positive polarity in order to extract ion beams [1]. Conversion to positive polarity was achieved by rotating all six of the adder cells by 180 degrees. In principle, we could have chosen to instead insert the center conductor from the other end of the adder to change polarity, but rotating the cells minimized the time required to make the transition. Although most of the same pieces were used, the center conductor had to be reconfigured in order to align the transition pieces with the cell feed gaps. Because the electron flow was anticipated to be very different in positive polarity as a result of emission from surfaces of different potential, a simple blade diode was fielded for the initial shots to gain a better understanding of operation in positive polarity. The blade diode consisted of the same cathode used as a dummy load in the first negative polarity shots on Mercury [2], but with a different carbon anode that just covered the end of the center conductor. After a few short circuit and initializing shots, a series of shots were taken where only the blade diode AK gap was varied in order to characterize self-limited and load-limited operation and to compare measurements with theory and simulation. Results will be presented and contrasted with negative polarity operation. *Work supported by DTRA and ONR a L-3 Communications, Titan Group, Reston, VA b National Research Council Research Associate [1] R.J. Commisso, et al., this conference. [2] R.J. Allen, et al., “Initialization and Operation of Mercury, a 6-MV MIVA,” 15th International Pulsed Power Conference (Monterey, CA, June 2005), p.339.
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04P-9: Benchmarking and Implementation of a Generalized MITL
Flow Model P. F. Ottinger, J. W. Schumer, H. D. David,
A. J. Allen Plasma Physics Division, Naval Research
Laboratory, Washington, DC, United States
A generalized magnetically insulated transmission line (MITL) flow model has been developed to treat dynamic MITL problems [1]. By including electron pressure in the model and allowing non-zero values of the electric field at the cathode, this MITL model can treat both emission and re-trapping of flow electrons. Most previous MITL flow models only describe equilibrium flow conditions without emission or re-trapping and cannot adequately treat dynamic situations. Such dynamic situations are common and include impedance transitions along the line, variable impedance transmission lines, coupling to loads, etc., all of which can cause electron emission from the cathode and/or electron re-trapping onto the cathode. The model is being benchmarked against particle-in-cell (PIC) simulations using the LSP code [2]. Of particular interest for this benchmarking effort is the treatment of re-trapping waves that occur when the MITL is terminated by an under-matched load. Ultimately, the model will be incorporated into a transmission line code such a BERTHA [3] so that MITL problems can be studied more quickly and efficiently than with PIC codes. Available results will be presented. *Work supported by DOE through SNL [1] Generalized Model for Magnetically Insulated Transmission Line Flow, P.F. Ottinger, J.W. Schumer, D.D. Hinshelwood, and R.A. Allen, IEEE Trans. Plasma Sci. 36, 2708 (2008). [2] LSP is a software product of ATK Mission Research, Albuquerque, NM 87110. [3] Bertha a Versatile Transmission Line and Circuit Code, D.D. Hinshelwood, NRL Memo. Rpt. 5185, Nov. 21, 1983.
04P-10: A Stacked Transformer Modulator that Delivers high Voltage at
High Rep-Rate and Duty Factor
G. Saewert, H. Pfeffer,
Fermi National Accelerator Laboratory
A modulator has been built to drive the gun anode of the Tevatron Electron Lens (TEL) at Fermilab. High voltage applied to the gun defines electron beam current in order for the TEL to perform beam-beam compensation in the Tevatron on each of the 36 (anti)proton bunches. Every bunch requires its own defined current, and the value of current for each bunch is different on each Tevatron "store". These requirements demand the modulator deliver a complex voltage waveform with a high duty factor, and high repetition rate to voltages exceeding 5 kV. The modulator described here utilizes a novel circuit topology to be able to produce sustained complex voltage waveforms having peak voltages of 6 kV that can have average periodic rates up to 420 kHz and transition to different voltage values at 395 ns intervals. This modulator employs 5 pulse transformers that have the secondaries connected in series to deliver high voltage output. This paper describes the design approach taken to leverage the virtues of transformers for high rep-rates and duty factors while minimizing the adverse effects of parasitics. Details of the hardware, the controller and performance results are presented.
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04P-11: Development Concept of High-Current Accelerators with High Pulse
Repetition Frequency Within Wide Range of Output Parameters.
A. V. Gunin, V. V. Rostov, A. S. Stepchenko, V. V. Gubanov, V. N. Kiselev
SB RAS, Institute of High Current Electronics, Tomsk, Russian Federation
The concrete realizations of accelerators SINUS in wide range of output parameters working with high pulse repetition frequency are considered. The basic parameters of setups are given. The principle of design of the computer control system in the accelerators SINUS is described. The results of real testing are showed that this command control allows in a mode of real time to control of output parameters and to prevent occurrence of emergencies. The concept of “Batch” mode of operations with high frequency is considered which has a number of advantages for the laboratory researches. The power dissipation in the different path of setup is simulated and the total efficiency of setups is given. The analysis of possible application of principles of energy transformation in the SINUS setup for creation long pulses sources on artificial pulse forming network capable to work with high repetition frequency is carried out.
04P-12: Development of a 1-MV, 1-MA, Rep-Rate Linear Transformer Driver at
SNL K. R. LeChien1, M. G. Mazarakis1, W. E. Fowler1,
W. A. Stygar1, A. A. Kim2 1Sandia National Laboratories, Albuquerque, NM,
United States 2High Current Electronics Institute, Tomsk,
Russia Sandia National Laboratories (SNL) is pursuing linear transformer driver (LTD) architecture as a primary driver for z-pinch, radiography, inertial fusion energy (IFE), and isentropic compression experiments (ICE). A significant advantage to the self-contained LTD geometry is that energy storage and pulse forming are conducted in a single matched impedance arrangement with individual stage triggering that provides exceptional control over pulse shape when utilized with a water-filled coaxial transmission line configuration, all in a minimized volume. We are developing a fully automated, 10-cavity system capable of 2 to 3 shots per minute called Mykonos, which is constructed from LTD cavities developed at the HCEI in Tomsk, Russia. The cavities are modified to accommodate a water filled A-K region, increase switch gas throughput, and individual cavity diagnostics. The output of the Mykonos driver is nominally 1-MV, 1-MA, 1-TW with a 10 – 90 risetime of ~60-ns and a ~150-ns FWHM into a matched impedance load (1-) when synchronizing the pulse for maximum current output (all switches triggered at optimal time to maximize the forward going wave). The Mykonos driver is the first LTD induction voltage adder utilizing water insulation. The resulting longer cavity-to-cavity transit-time as compared to a vacuum insulated system allows pulse shaping capabilities without expanding the length of the system (there is no additional pulse-sharpening and no multimegavolt water switches). With a single cavity transit time of ~7-ns, the risetime may be increased to ~120-ns (10 – 90) with a FWHM of ~190-ns simply by reversing the triggering order of the cavities. Each cavity contains 40 bricks and each brick consists of a pair of 40-nF capacitors switched by a multichanneling, multigap, air-filled switch. The equivalent capacitance of a cavity is 800-nF with a series inductance of 5-nH and series resistance of 5-m. There is a ~1.5- parallel resistive element due to the iron-core loss. The V-s integral for the cores of a single cavity is ~20-mVs. The cores are reset via a ~2 kA pulse that rises in ~55-s and decays to zero in ~1-ms. There are current and voltage diagnostics every five cavities and at the resistive load. Initial design and engineering for the Mykonos driver began in January 2008. Pulsed power development begins in calendar year 2010, and
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should continue until early 2011. After this initial development phase, experimentation will continue with investigation of pulse shaping capabilities, possibly including a tri-pate exponential impedance transformer for ICE applications. Additional experiments will continue with scaling LTDs for petawatt IFE accelerators and rep-rate applications. The proximity of the laboratory to Z-Beamlet allows for future laser diagnostic capabilities.
04P-13: High Voltage Semiconductor Pulsed Generator for Producing the
Oxide Nanostructures Water Dispersions P. G. Rutberg1, I. V. Grekhov2, V. A. Kolikov1, S. V. Korotkov2, I. A. Rolnik2, V. N. Snetov1,
A. Y. Stogov1 1Institute for Electrophysics and Electric Power Russian Academy of Science, St. Petersburg,
Russian Federation 2Ioffe Physico-Technical Institute Russian
Academy of Science, St. Petersburg, Russian Federation
High voltage pulsed generator with the powerful semiconductor switch - reversely switch-on dynistor (RSD) for producing the oxide nanostructures water dispersions by means of electrodischarge processing of water in this investigation was applied. In this device, the electric pulses are powered from capacitor energy storage by means switching by RSD. Step-up pulsed transformer and output circuit with the matching capacitor ensure high efficiency of energy transfer to the load. Distributions in size of Pt, Ag, Cu, Fe, Ti and Zn nanostructures in water dispersion as a function of electric pulses parameters were investigated. It was shown that all used metals produce nanostructures, which size depends both on a metal of the electrodes, and from parameters of electric pulses. Distribution of nanoparticles in size (hydrodynamic radius) is characterized by some peaks ranged from 9 nm (Ag) up to 500 nm (Zn).
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04P-14: Damping Resonant Current in a Spark-Gap Trigger Circuit to Reduce
Noise E. L. Ruden1, D. J. Brown2, T. C. Grabowski2, C. W. Gregg2, B. M. Matinez2, J. V. Parker2, J. F. Camacho3, S. K. Coffey3, P. Poulsen4
1Directed Energy Directorate, Air Force Research Laboratory, Kirtland AFB, NM, United States
2Science Applications International Corporation, Albuquerque, NM, United States
3NumerEx, LLC, Albuquerque, NM, United States 4CARE’N Co., Livermore, CA, United States
Radio frequency (RF) interference (noise) caused by the triggering of spark-gap switched pulsed-power circuits is a significant problem for electronic diagnostics. Traditional approaches to mitigation involve using RF-tight enclosures, noise resistant diagnostic designs, power filtering, and/or time-integration of signals. These approaches can be costly, and not always successful. A detailed study of the source of this noise is undertaken motivated by an experiment using a charged coaxial cable triggered rail-gap (multichannel linear spark-gap) switched system based on a half-module of AFRL's Shiva Star Capacitor Bank. For this, the noise interferes with an unintegrated measurement needed of the load's local electric field. The noise source is identified as resonant current oscillation after rail-gap closure in the circuit triggering the rail-gaps. The solution in this case is to replace the 50 Ohm trigger cable with one with half that impedance, and install a thin film resistor in series with the cable output with a resistance equal to the new cable's impedance. The output impedance of the trigger circuit and, therefore, the rail-gap current behavior during breakdown is thereby preserved, but reflections back into the cable after switch closure are minimized by impedance matched resistance termination. In practice, termination is compromised by lead inductance and blocking capacitors, but near-critical damping of subsequent resonant behavior is nonetheless observed. A circuit model of this behavior is validated to help adapt and optimize the technique for other systems.
04P-15: A MV Marx Generator Modified for Nanosecond Risetime
T. A. Holt, M. B. Lara, J. R. Mayes, M. G. Mayes Applied Physical Electronics, L. C., Austin, TX,
United States Traditionally, the MV Marx generator offered by APELC [1] operates at a charge voltage of 40 kV, an erected voltage of 1.6 MV, a stored energy of 260 J, and an output pulse risetime between 6-8 ns. APELC has developed a pulse conditioning system that can be retrofitted into the existing MV Marx generator housing to improve peak load voltage and output pulse risetime at a minimal cost of stored energy. The overall energy density of the system decreases from 4.45 mJ/cm^3 to 3.86 mJ/cm^3, however the volume occupied by the Marx generator remains the same. The performance characteristics of the newly developed pulse conditioning system driven by a slightly modified version of APELC’s MV Marx generator will be provided. [1] J. R. Mayes, M. M. Mayes, M. B. Lara, "A Compact MV Marx Generator," Proceedings of the 2004 Power Modulators and High-Voltage Conference, San Francisco, CA, 2004.
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04P-16: A Modular PFN Marx with a Unique Charging System and
Feedthrough D. T. Price, R. J. Adler, J. A. Gilbrech
Applied Energetics, Tucson, AZ, United States
We have developed a reliable, high burst power Marx generator system capable of operation at up to 550 kV/11 kA with an output flat top of 1 usec nominal. The unit can operate at up to 5 Hz for 2 seconds (>30 kW output) from a power supply with a "built-in" HV section. It consists of 14 series type C PFNs each with an impedance of approximately 3.5 ohms. The individual PFNs are built so that they are easily removed and modified. With this flexibility, the unit can be adapted to changes in the load such as those due to diode impedance collapse. The HV section of the HV power supply is section is not only in the Marx oil bath but it is "connected" to the semiconductor portion of the power supply using "air core magnetic flux coupling". This technique is as far as we know unique, and it eliminates the requirement a high voltage or high current wired feedthrough in the system. It also dramatically reduces EMI coupling from the Marx to the semiconductor power supply modulator and the control system. The efficiency of this supply is approximately 80 % even with the use of this technique. In the paper we will discuss the theory of the coupling and the experimental results of operation of the power supply and Marx.
04P-17: 125kV, 100kA, 150ns, 5pps Test Facility with Solid State Switched
Distributed Pulse Compression Marx S. C. Glidden, H. D. Sanders
Applied Pulsed Power, Inc., Freeville, NY, United States
Electra is a repetitively pulsed, electron beam pumped Krypton Fluoride (KrF) laser at the Naval Research Laboratory. This program is developing technologies to meet the Inertial Fusion Energy (IFE) requirements for durability, efficiency, and cost. The Electra laser main amplifier requires a 500kV, 100kA, 150ns, 5Hz pulsed power source. At present, the main amplifier uses gas insulated spark gap switches with lifetimes of 10^5 pulses. Solid state switched pulsed power sources are being developed to achieve lifetimes of 10^8 pulses. Applied Pulsed Power has developed a 48kV compact solid state switch for this application that operates at 8kA and can withstand fault currents of 14kA and 80% current reversal. Individual modules used in the switch have been tested for >200 million pulses without failure, and lifetime testing of the complete switch is in progress. Using these switches, we are manufacturing and testing a quarter scale version of the Electra pulsed power source. Scaling was done by reducing the number of Marx stages and the impedance of the downstream pulse forming components and load by a factor of four, resulting in a 125kV, 100kA, 150ns, 5pps test facility. This approach ensures each Marx stage operates at the design voltage and current, and the pulse forming components and magnetic switches operate at the same design current and timing as for the full scale system. The electric fields in the pulse forming components for the quarter scale version exceed the design values for the full scale system. This system uses a six stage, solid state switched, distributed pulse compression Marx (DC Marx). The DC Marx provides one level of magnetically switched pulse compression with a gain of 3 in each stage of the Marx. By distributing the pulse compression among the stages of the Marx, the initial pulse compression is performed at the stage voltage rather than the full output voltage. This design also removes the solid state switches from the Marx output current path. Two solid state switches are used for each stage resulting in a 48kA peak Marx current. The DC Marx is followed by two-stages of pulse compression using water insulted coaxial lines and magnetic switches. The 1.25 ohm PFL is switched into two parallel connected 2.5 ohm output lines terminated with 2.5 ohm water resistors. The system will be operated at 5pps and tested for 10^7 pulses. Testing will also be performed to determine the effects of various system faults.
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This paper will describe the system design and present initial DC Marx test results. This work supported by the Naval Research Laboratory, Laser Plasma Branch.
04P-18: Repetitive Auto-Triggered Marx Generator for an Ultra Wideband Source
B. Cassany1, P. Modin1, B. Cadilhon1, A. Silvestre de Ferron2
1Div. DEV/SEMR/LSRV, CEA DAM, Le Barp, France
2Electrical Engineering Laboratory, Pau University, France
The interest for high voltage repetitive generators has risen in a wide range of applications such as high power microwave (HPM) systems or ultra wideband (UWB) radar. Traditional uses of the Marx generator have been limited to energy storage and delivering systems, such as charging capacitors or pulse forming lines. However, low energy, compact, high peak power Marx generators can be used as repetitive drivers for many applications. This paper presents the design, the realisation and experimental tests of a repetitive auto-triggered Marx generator expected to be the driver of a broadband system. This whole system consists of a pulsed power source, i.e. a pulse forming line charged by a Marx bank and an UWB antenna array. Design of the Marx generator were planned to reach a voltage level of up to 400kV, a 200Hz repetition rate and a good reproducibility. In this way, the generator is supplied with a high voltage pulsed power supply; charging and discharging circuits were made of home-designed inductors. Furthermore, we focus on the first stage of this Marx generator in which a new simple auto-triggered spark-gap was integrated. Added to a strong ascending arrangement of the ten gap lengths, it confers to the output signal a very high reproducibility both in magnitude and time and permits to reach high repetition rate.
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04P-19: Experimental Results on Design Aspects of a Compact Repetitive Marx
Generator A. Sharma, S. Mitra, S. K. Sharma, K. V. Nagesh,
D. P. Chakravarthy, P. D. P., A. K. Ray Accelerator & Pulse Power Div., Bhaba Atomic Research Centre, Mumbai, Maharashtra, India
This paper presents the experimental results of a repetitive marx generator being developed at BARC. Effect of lead inductance, sparkgap alignment, charging inductor, ground inductor and shielding have been studied. Two types of configurations have been adopted in order to reduce the erected mrax inductance and results are compared. In this Marx generator plus-minus charging scheme was adopted for both test setup. Each setup comprised of 2-stage marx with 4 series capacitors (each rated for 0.15 microferad, 40nH, 50kV) while discharging giving 0.375 microferads capacitance. In one of the scheme Type-I, all sparkgaps were aligned in line of sight arrangements and successive discharge path were assemled in a zigzag manner so that the induced magnetic field gets cancelled out and effective inductance is reduced. This scheme was termintaed to an aqueous load and critical matched condition was achieved at 12 ohm. This scheme had effective capacitance of 0.375 microferads, and overall inductance 1.5microhnry. It gave output voltage pulse of 1.8 microseconds duration in critical damping condition. This had diameter of 500mm diameter for a length of 600mm long assembly. In case of other configuration named as Type-II assembly, sparkgaps were not in line of sight, all capacitors were connected length wise and discharge was only in forward direction, it was found that besides being longer (~900mm) and smaller in diameter (~400mm) this scheme gave smaller inductance keeping all other parameters such as capacitors, charging inductors same. It had an erected inductance of 750nH for 4-capacitors, plus-minus charged marx generator assembly. This had lower matched impedance also giving rise to higher current capacity for this type of marx generator. It was criticaly matched with 9 ohm load and output pulse had 1 microsecond duration. These results matched with simulated waveshape in matlab-simulink circuit also. During testing it was found that keeping charging inductor 8microhenry is sufficient to give desired discharge path without affecting source side. No improvement even if it is increased to mH level. End inductor from ground to peaking gap was also not showing any significant improvement in the waveshape in lower voltage i.e. 10-15kV charging level. During experiments effect of load was also seen which gave halg th eopen voltage to matched load [sqrt(L/C)] and in critical damping condition
voltage was o.7 times of open circuit voltage. These data will be used for developing a 6-stage 1.2 kJ Marx generator for 20 pps burst output. Presently testing is limited to 2pps due to charging power supply limitations. Thus the results can be summarised as follows: (i) line of sight and ultra violet triggering is not effective for a distance of 200mm, (ii) cancellation of induced magnetic field is not effective at 5kA curent peak at 100mm ditance, (iii) longer length leads in smaller diameter is preferrable over larger diameter with smaller legth assembly with zigzag leads for giving shorter pulse, higher current and faster rise time.
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04P-20: Investigation of Spark Gap Discharges in a Regime of Very High
Repetition Rate H. Rahaman1, S. H. Nam1, S. H. Kim1,
S. S. Park1, S. H. Kim1, H. Heo1, O. R. Choi1, S. C. Kim1, K. Frank2
1Pohang Accelerator Laboratory, Pohang, South Korea
2Center for Pulsed Power and Power Electronics, Texas Tech University, Texas, United States
High pressure discharges in two electrode gap systems (spark gaps) are widely used for fast switching (sub nanosecond) devices in pulsed power. Typical pressure is greater than 10 bars in such conditions and the inter-electrode distance is larger than several millimeters. The dynamic recovery process of the gas, in principle, limits the repetition rate. However, when the gap spacing decreases the switching time decreases as well so that even with a pressure close to 1 bar it becomes possible to obtain the fast switching. In addition, the time for the recovery process decreases, which can be prerequisites for the switch operation at the high repetition rate. An approach is followed that focuses discharges in electrode gaps (on the order of 100 μm) inside a coaxial type geometry at low charge content or energy content. Several parameters for this purpose such as the electrode gap distance, electrode geometry, gas type, gas pressure, and including the applied voltage and current ratings from the power supply have been varied, which in one or other way dependent on each other. It has been demonstrated that with optimized parameters, discharges in the spark gap is capable of generating sub nanosecond rise time current pulses at a matched load with the repetition rate exceeding 1 MHz.
04P-21: Compact All Solid State Pulsed Power Generator Driven by FPGA M. Akiyama1, K. Kouno1, K. Kawamoto1,
T. Sakugawa1, H. Akiyama1, K. Suematsu2, A. Kouda2, M. Watanabe2
1Kumamoto Univercity, Graduate School of Science and Technology, Kumamoto, Japan 2Suematsu Electronics Co. Ltd., Kumamoto,
Japan
A high-reliability, a high repetition rate and a compactness of pulsed power generator have been required with the spread of industrial applications. It becomes more complicated with the increase of functions. A field programmable gate array (FPGA) is able to control an all solid state pulsed power generator using semiconductor switch. This pulsed power generator consists of a controller, a command capacitor charger, a pulsed power modulator using insulated gate bipolar transistor (IGBT) switches and a magnetic pulse compression (MPC) circuit. The performance of this pulsed power generator such as variable pulse repetition rate, diagnosis of incorrect operation and control of a liquid crystal display (LCD) can be achieved easily by rewriting the programming of Verilog hardware description language (HDL). This pulsed power generator using a FPGA becomes more compact in comparison with conventional pulsed power generator using a logic IC circuit. This pulsed power generator with a high-reliability, a high repetition rate and a compactness will be able to be used in industrial applications such as ozonizer, water treatment, exhaust gas treatment, cleaning of lakes and marshes, sterilization and so on.
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04P-22: A Compact, Low Jitter, Fast Rise Time, Gas-Switched Pulse Generator
System with High Pulse Repetition Rate Capability
R. J. Focia1, C. A. Frost2 1Pulsed Power Laboratories, Inc., Edgewood,
NM, United States 2Pulse Power Physics, Inc., Albuquerque, NM,
United States
We present the experimental results of a research effort focused on development and refinement of a compact, low jitter, fast rise time, command triggered, high peak power, high pulse repetition rate (PRR), gas-switched pulse generator system. The main component of the system is a gas-switched Marx-like pulse generator module designed for applications including UWB radar, microwave sources, and triggering large scale multi-module pulsed power systems of all types. The pulse generator system, comprised of a single or multiple Marx modules, is command triggered by a single or multiple TTL level pulses generated by a timing and control system implemented using LabVIEW software and a PXI-based hardware system. The TTL trigger pulses fire all solid-state high voltage trigger pulsers that close the first stage switches in the Marx modules. The control system also accepts user input to set the desired output conditions, adjusts the charge voltage of a high voltage capacitor charging power supply, inhibits capacitor charging during firing of the pulse generators, and can control the system in a closed-loop fashion to maintain relative timing and output characteristics during timing drifts and changing environmental conditions. The individual Marx stages are compact and stackable and utilize field enhanced spark gap switches. The stage capacitors are charged in parallel through mutually coupled inductors in series with resistors. This charging scheme allows for high PRR operation limited only by the stage switch recovery time and the power of the capacitor charging power supply. The stage switches are optically coupled to aid in Marx output voltage formation and to minimize system jitter. The Marx generator is housed in a lightweight aluminum pressure vessel and is operated in a low pressure dry air environment. The design exhibits a low inductance which varies depending on the number of stages used. Using a five stage prototype, we have generated output voltages of ~100 kV with a rise time of <4 ns. The output pulse width is variable and is dependent on the value of the Marx stage capacitors used and the load resistance. The pulse generator system has been operated in a burst mode at a PRR in excess of 1 kHz with good output voltage regulation. The total jitter of the Marx generator system, i.e. from the
application of the trigger pulse to arrival of the output pulse, was measured and found to be <1 ns.
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04P-23: An All Solid-State Pulsed Power Generator with Semiconductor and Magnetic Compression Switches
K. Liu, D. Wang, J. Qiu Institute of Electrical Light Sources, Fudan
University, Shanghai, China
An all solid-state pulsed power generator is designed based on semiconductor and magnetic compression switches. It combines the characteristics of semiconductor switches with long life times, repetitive and controllable operation and magnetic switches with pulse compression and fast rise time. It eliminates a transformer and provides high voltage pulse by semiconductor switches series during pulse output. At the last stage the magnetic compression switch is used for sharpening the rise edge of output voltage. Special attention was paid to the design of magnetic compression switch in order to match its volume, V-S integral with the circuit parameters. A system of pulsed power generator with output voltage of 40kV, pulse frequency of 2kHz and pulse width of 400ns was accomplished, which meets the requirement of pulsed discharge plasma for waster water treatment.
04P-24: Compact and RepetitiveTesla-Based Power Source
B. M. Novac, P. Sarkar, I. R. Smith, C. Greenwood
Electronic and Electrical Engineering, Loughborough University, Loughborough,
Leicestershire, United Kingdom
The paper details the development of a very compact (diameter = 100 mm, length = 840 mm) battery powered, high repetition rate pulsed power source. Tesla technology is employed in the generation of a high output voltage and the source is capable of producing voltage pulses of up to 250 kV. Details are given of the conductor topology adopted to achieve a low inductance configuration, together with the high repetition rate closing switch based on corona stabilisation and the 2D modelling of the Tesla transformer. Experimental and predicted results are presented, and the accurate comparison obtained opens the way to future designs.
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04P-25: Testing a Scaled Pulsed Modulator for an IEC Neutron Source into
a Resistive Load G. E. Dale, R. M. Wheat, R. Aragonez
ISR-6, Los Alamos National Laboratory, Los Alamos, NM, United States
A pulse modulator for an Inertial Electrostatic Confinement (IEC) neutron source is currently under development at Los Alamos National Laboratory (LANL). The IEC neutron source requires that a high electric potential be maintained between two grids within a hydrogen plasma. The grid potential, often in the range of 100–200 kV, is generally established with DC power supplies. Current-limiting resistors are used between the power supply and the grid to protect the power supply from overcurrent resulting from an arc within the plasma. While effective at protecting the power supply from an over-current fault, this current-limiting resistor dissipates a significant amount of power. The use of a pulsed modulator to supply the grid potential to an IEC modulator will have several benefits. One benefit is the ability to produce a pulsed source of neutrons from an IEC device. This ability is important because there are several applications which require a pulsed source of neutrons. The pulsed modulator is also designed to run at a high duty factor, up to 5%. When the modulator is run in this mode the pulsed-neutron source looks much like a continuous source of neutrons. Therefore, only one power supply is necessary for both pulsed and continuous modes of operation. Another benefit of using a pulsed modulator is that it has the potential to improve system efficiency. The pulsed modulator proposed for this design has the ability to self limit the current during arcing or shorted-load faults. This protection is completely passive yet does not dissipate power during normal operation, increasing the system’s efficiency. These types of protection schemes are generally not available with high-voltage DC power sources. The design of the pulsed high-voltage source is based on a solid-state Marx architecture developed at LANL. This paper describes the design, construction, and initial test results of a scaled prototype modulator for the IEC neutron source. The modulator prototype is scaled to 1/10th the output voltage of the final design to allow air-insulated operation of the scaled prototype. * Work sponsored by Los Alamos National Laboratory under US DOE contract W-7405-ENG-36.
04P-26: Pulse Power Electromagnetic Fields, Rep-Rate Influence on
Electromagnetic Effects L. Palisek, L. Suchy
VTUPV Vyskov, VOP-026 Sternberk, s.p., Sternberk, Czech Republic
Pulse power electromagnetic fields like NEMP (Nuclear Electromagnetic Pulse), HPM (High Power Microwave) and UWB (Ultra-wide Band) are considered as a possible threat for sensitive electronic equipments. While NEMP is considered as a typical single pulse threat, HPM and UWB are often considered as signals with possibility of repetition rates according to state of the art technologies. Some results obtained during experimental measurements of susceptibility of electronics to HPM and UWB irradiation with repetition rate signals will be presented. Repetition rate dependence will be considered for temporary failures as well as for damage levels too. As equipment under test will be chosen regular PC setups. Simple electronic circuit will be added for some experiments for possibility to achieve more results related to damage levels. Suitable simplified circuit models for HPM and UWB repetition rate effectiveness for achieving of typical effects on electronics will be considered and used for simulations. Results from measurements will be compared with results from simulations. At the end of this presentation recommendation for effective HPM and UWB rep-rate necessary to achieve typical failures of tested equipments will be carried out.
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04P-27: A High Voltage Power Converter with a Frequency and Voltage Controller
S. Zabihi1, F. Zare1, H. Akiyama2 1QUT, Brisbane, Australia
2Kumamoto University, Kumamoto, Japan
This paper presents a new voltage and frequency control system for a voltage multiplier to improve quality of output voltage for both pulsed power and high DC voltage applications. It consists of an AC-DC converter to provide an adjustable DC voltage while the input power factor is controlled. The second converter is a DC-AC inverter which generates AC voltage with variable frequency and the third converter is a voltage multiplier with diodes and capacitors. A traditional diode capacitor voltage multiplier has several constrains such as limited output power and low order harmonics when it is connected to a power grid with a constant frequency and voltage (for example 50 Hz, 220 V), Dynamic performance of a voltage multiplier using a low frequency AC power supply is poor. In fact each charging step takes 20 ms (in a 50 Hz system) to increase the output voltage. Thus the converter cannot keep the output voltage at high level when load current is increased. In a new configuration, two converters are in cascade and they are connected to a to an AC-DC voltage multiplier. The first converter consists of a diode rectifier with a boost converter which improves the input power factor and reduces low order harmonics. The controller changes the DC voltage based on the reference voltage to generate a high voltage at the output of the third converter. In a traditional diode capacitor voltage multiplier, the output voltage depends on the number of capacitors and diodes and input voltage magnitude. As the grid voltage is constant (220 V), it is not possible to change the output voltage easily. While in this topology, the output DC voltage of the first converter is controlled. The second converter is an inverter which generates an Ac voltage with a variable frequency. The controller measures the output voltage error and changes the frequency of the inverter to increase the number of charging steps. As the switching loss in the inverter is increased when the output frequency is increased, thus the inverter output frequency is changed based on load current. This can improve the efficiency of the system. In this research work, several simulations have been carried out using Matlab/Simulink and Pspice in order to analysis steady state and transient performance of the converter at different load conditions and validate the control algorithms. Simulation results show that by controlling the frequency of the input voltage, we can increase the number of charging steps and
improve the output voltage. The converter can adjust output voltage using unipolar modulation in which by changing pulse width, the output voltage can be controlled while using a bipolar modulation the output voltage depends on the number of diode-capacitors stages in the voltage multiplier circuit.
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04P-28: High Voltage Pulsed Power Using a Current Source for a Plasma
System S. Zabihi1, F. Zare1, H. Akiyama2
1Engineering Systems, QUT, Brisbane, Australia 2Pulsed Power, Kumamoto University,
Kumamoto, Japan
Excessive power loss in plasma generators reveals that a review on power supply properties is necessary to improve efficiency in plasma systems. Voltage source topologies such as either diode-capacitor multipliers including Dickson charge pump and Cockroft-Walton multiplier or Marx generators used to generate high voltage for pulsed power applications. These configurations can be modelled with a charged capacitor which is connected in parallel to the electrodes energizing the material to form the plasma. The capacitors high voltage over electrodes resumes plasma formation. In plasma generation trend, there is an inevitable phenomenon, happening after plasma reactions, which is a kind of short circuit inside the plasma containers. Just after plasma reaction, the material resistance intensively collapses and it draws enormous current. This short circuit may cause the capacitor to get fully discharged and the stored energy to transfer to heat. This phenomenon is naturally power consuming while there is no control on circuit to stop current flowing through between the electrodes in the voltage source topologies. Obviously, the system efficiency will be severely influenced by an effective and smart current control which limits power flow to the plasma system when a short circuit happens. A modified positive buck-boost converter working in discontinuous mode with current control is novel suggestion which could be employed to feed plasma generators. The high voltage will be generated when buck-boost converter works in discontinuous mode. The delivering energy to the electrodes will be controlled when the flowing current level being under control. This topology consists of two power switches controlled independently to satisfy desired control goals. A hysteresis block control keeping inductor current almost regulated, compares sensed current with bands borders and turns on/off the power switches. A control block monitoring voltage between electrodes turns on a switch situated in parallel with the current source as soon as the voltage becomes less than a defined amount. That means the system intelligently identifies that the plasma is formed and the next cycle can be started without dissipating energy across the plasma electrodes. In this topology, the stored energy in inductor will be delivered to the plasma; therefore the
maximum possible voltage over the electrodes can be calculated based on the following equation: 1/2 L x i x i=1/2 C x V x V Where L is the inductance of the current source and C is the capacitance of the load. Considering switching transients, when the switch in parallel with the current source is turned off, the current through the plasma is increasing. Thus dv/dt across the electrodes depends on the current level and also capacitance value (C). In fact dv/dt is increased as the load current is increased according to this equation: dV/dt=i/C. In this control technique, we can also measure the output voltage and keep it below a voltage level to prevent any breakdown between the electrodes. for below the breakdown voltage. This considerable voltage stress coincided with adequate current leads plasma generation.
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04P-29: Design and Construction of a Corona Charged High Power Impulse
Generator F. Vega1, 2, N. Mora1, F. Roman1, N. Peña3,
F. Rachidi2, B. Daout4 1National University of Colombia - EMC UN,
Bogota, Colombia 2Swiss Swiss Federal Institute of Technology –
EPFL, Laussane, Switzerland 3Andes University-GEST, Bogota, Colombia
4Montena EMC, Rossens, Switzerland
A prototype of an impulse generation system based on a corona current charging mechanism is presented. The system is capable of delivering 30 kV short pulses of about 1 ns of rise time. To simulate the generator pulse repetition frequency an electric model based on the unipolar corona charge current approximation was developed. The results obtained using the developed model are compared with experimental data showing good agreement.
04P-30: Modeling Fluid/Structual Interaction in a Pulsed Power Accelerator
J. A. Lips 1655 Pulsed Power Engineering, Sandia National
Labs, Albuquerque, NM, United States
A key component of pulse power technology is in the engineering of these complicated structures. The goal of this work is to develop a finite element model that captures the complex physical interactions of all components within the Z machine. The biggest driver of physical motion in this machine is not found at the target but rather upstream at the water switches. Where this high current passes through the water a strong acoustic wave is generated. The pressure in an individual wave is fairly weak, only approximately 500 psi peak pressure. However, due to the number of these switches (108 total), the axial symmetry of these switches, and switch timing, the impulse generated by these waves has the potential to create significant damage within the structure. Modeling this type of fluid/structure interaction on this scale pushes many finite elements codes to the limit of their capabilities. In order to get the correct input to the model great care must be taken in the selection of a sensor deployed to capture this wave time history. A number of technologies have been investigated via shock tube testing. In a shock tube a square wave can be transmitted through air or water to the sensor mounted in the tube end cap. From this test the sensor rise time, response frequency, and decay can be evaluated for suitability in this application. Sensor technologies studied include off the shelf quartz pressure sensors, Polyvinylidene Fluoride (PVDF), and PDV interferometry with thin film TPX. A number of modeling approaches have been investigated during the course of this work including structural/acoustic elements, Arbitrary Lagrangian Eulerian (ALE), and Coupled Eulerian-Lagrangian (CEL). A coupled Eulerian-Lagrangian approach was ultimately selected for this effort. This technique allows the structural mesh (Lagrangian) to occupy the same volume in space as the fluid mesh (Eulerian). A third component, the Eulerian material (water in this case) flows through the Eulerian mesh and interacts with the structure via general contact. Techniques for initiating such acoustic waves in the Eulerian domain, as well as techniques for getting the correct reflection/transmission response at the fluid-structure interface have been studied.
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04P-31: Cygnus Source Emission D. Nelson1, E. C. Ormond1, M. E. Burke1, S.
Cordova2, I. Molina2, E. A. Rose3, M. J. Berninger4, R. E. Gignac4, D. E. Good4, M. D. Hansen4, D. J. Henderson4, S. S. Lutz4,
C. V. Mitton4 1Sandia National Laboratories, Mercury, Nv,
United States 2Sandia National Laboratories, Albuquerque, NM,
United States 3Los Alamos National Laboratory, Los Alamos,
NM, United States 4National Security Technologies, North Las
Vegas, Nv, United States
The Cygnus Dual Beam Radiographic Facility consists of two identical radiographic sources each with a dose rating of 4-rad at 1 m, and a 1-mm diameter spot size. The development of the rod pinch diode was responsible for the ability to meet these criteria. The rod pinch diode in a Cygnus machine uses a .75-mm tungsten diameter tapered anode rod, which extends 10-mm through a 9-mm diameter cathode aperture. The electron beam born off the aperture edge can self-insulate and pinch onto the tip of the rod, creating an intense, small x-ray source. The Cygnus sources are utilized as the primary diagnostic on numerous experiments which include high-value, single-shot events. In such an application there is an emphasis on reliability and reproducibility. A shot-to-shot evaluation of the machine performance will be conducted and evaluated using an x-ray pinhole camera. * Work supported by Sandia National Laboratories. Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under Contract DE-AC04-94-AL85000.
04P-32: Microwave Shielding Measurement Method L. L. Hatfield, B. Schilder
Electrical Engineering, Texas Tech University, Center for Pulsed Power and Power Electronics,
Lubbock, United States
A simple system for measuring the attenuation of microwaves in the frequency range of 700 MH to 13 GHz is described. It has been used to test a large number of commercially available microwave shielding materials. The standard system for such measurements would require IEEE STD 299 2006. This standard requires a number of different sources and receivers depending on the frequency range and, therefore, requires a number of different physical arrangements. The simple system described here uses two microwave horns and a network analyzer to compare the signal strength for an open path between the two horns with the same path with a microwave shielding material inserted. This ratio, expressed in db, can be obtained quickly and easily for any material that can be made into a flat rectangle larger than the receiving horn. The horns used here are A. H. Systems SAS-571 with a usable range of 700 MHz to 18 GHz. The network analyzer is an hp 1397C with a high frequency limit of 13 GHz. The materials tested include conducting paints on cloth such as denim, conducting woven fabrics, and metal meshes. The typical measurements presented here to illustrate the use of the method show that conducting paints and conducting fabrics mostly show large attenuation over the quoted frequency range although almost never as high as stated by the manufacturer. When the manufacturers quote the standard used for their measurements, it is sometimes an obsolete standard that has been withdrawn.
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04P-33: Electro-Dynamic Force Analysis of Armature-Rail Tight Contact
M. T. Li1, 2, P. Yan1, W. Q. Yuan1, Y. Zhou 1,2, 3, J. Wang1
1Institute of Electrical Engineering, Chinese Academy of Sciences, BeiJing, China
2Graduate Univerdity, Chinese Academy of Sciences, BeiJing, China
3School of Automation and Electrical Engineering, Tianjin University of Technology
and Education, TianJin, China
Large transient electro-dynamic force is generated by high pulse current in electromagnetic rail-gun, which pushes the armature sliding along the rail until it reaches the muzzle. To realize the target velocity, the armature-rail contact should be tight under appropriate pressure, which is also aroused by Electro-dynamic force. The contact pressure change according with the transient electro-dynamic force. To acquire the detailed information about electro-dynamic force of armature-rail, a finite element model is built by multi-physical fields coupling method. This method takes infinite field effect into calculation. The experiment is done in an electromagnetic rail-gun with C-shaped solid armature, and the experimental results verify that a new kind of optimized armature can keep the contact with the rail tightly at high velocity. As a result, the armature sliding velocity has been increased before armature transition happens.
04P-34: Current Distribution and Inductance Gradient Calculation at
Different Rail Geometric Parameters Y. Zhou1, 2, 3, P. Yan1, W. Q. Yuan1, J. Wang1,
M. T. Li 1,2 1Institute of Electrical Engineering, Chinese
Academy of Sciences, BeiJing, China 2Graduate School, Chinese Academy of
Sciences, BeiJing, China 3School of Automation and Electrical
Engineering, Tianjin University of Technology and Education, TianJin, China
For the convenience of experiment, a rectangle is widely-used as the cross section shape of rail in rail-gun systems at present. The rail geometric parameters, especially in the section orientation, may directly affect the current density distribution in rail-gun structure as well as inductance gradient (L′) of the rails. Current distribution is the effective factor that determines the efficiency of an electromagnetic launcher (EML) system. And L′ plays an important role in the performance of an EML system, moreover it determines directly the force that accelerate projectile. This paper investigates how the thickness, width and other rail geometric parameters, together with spacing, affect the current density distribution, magnetic flux density, and L′. Finite element analysis technique is employed to calculate these parameters using two-dimensional analysis. Several possible across section shapes of rail besides rectangle are discussed, respectively, including T-shape, annular shape, and waxing moon shape. The distribution of current density and L for various shapes and various dimensions are tabulated and compared.
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04P-35: Electro-Thermal-Mechanical Validation Experiments
L. K. Tully, J. M. Solberg, D. A. White, D. A. Goerz, J. S. Christensen, T. J. Ferriera,
R. D. Speer Lawrence Livermore National Laboratory,
Livermore, United States The design of high-performance electromagnetic launchers is dependent on intimate knowledge of the interaction between electromagnetics and solid/thermal mechanics. A coupled 3D electro-thermal-mechanical (ETM) simulation self-consistently solves equations of electromagnetics (primarily magnetostatics and diffusion), heat transfer (primarily conduction), and nonlinear mechanics (primarily elastic-plastic deformation and contact with friction). ALE3D is a heavily used Arbitrary-Lagrangian-Eulerian hydrodynamics code with a recently added electromagnetics simulation capability enabling the simulation, design, and optimization of ETM systems. Diablo is a relatively new ASC-class parallel coupled multi-mechanics code built from the legacy technology contained within the well-known LLNL-produced codes DYNA3D, NIKE3D, and TOPAZ3D. The coaxial validation experiment test fixture was developed to provide high-quality experimental data from a controlled environment undergoing large magnetically-induced deformations. This experimental data is particularly useful for the validation of coupling between J x B forces and momentum equations in ALE3D and Diablo. The coaxial validation experiment test stand was designed to handle a current injection of 1 MA via twelve cables connected to a 10 kV, 225 kJ capacitor bank. The application of high current levels into the shorted coax applies electromagnetically crushing loads to the aluminum center conductor. The aluminum center conductor test cylinders are of varying wall thicknesses, a nominal 6 inch working length, and 3 inch nominal diameter. A number of variations are possible, including cylinders with slots or other imperfections, for the study of both 2D and 3D effects. The coaxial test fixture also allows for validation of kink instabilities, buckling instabilities, and electrical contacts. The fixture is designed such that the cylinders can be instrumented with strain gauges and thermocouples connected to signal conditioners and digitizers within an EMI-protected enclosure. The test fixture also allows for Photonic Doppler Velocimetry (PDV) measurements of the radial tube displacements. Digital high-speed video is utilized to capture the rapid movement of the wall from a viewpoint within the center conductor of the structure. Accurate measurements of strain, temperature, displacement, and current have been recorded. Results from the implementation of diagnostics in this high electromagnetic field
environment and correlation to ETM modeling results will be discussed. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
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04P-36: A Simple Model of High-Power Thyristor and Its Application in EML
Transient Analysis Y. Zhou1, 2, 3, P. Yan1, W. Q. Yuan1, J. Wang1,
M. T. Li1, 2 1Institute of Electrical Engineering, Chinese
Academy of Sciences, BeiJing, China 2Graduate School, Chinese Academy of
Sciences, BeiJing, China 3School of Automation and Electrical
Engineering, Tianjin University of Technology and Education, TianJin, China
High-power solid-state switchs are introduced to electromagnetic launchers (EML) as leading switch technology, which make the system superior of improved energy efficiency and reduced volume. The semiconductor device models available in most circuit simulation software packages do not accurately characterize high-power thyristors for thermal management and snubber design. A simple PSpice model for high-power thyristor is proposed, which is based on the device behavior rather than on the physical structure. It can describe the forward and reverse recovery process with relative accuracy. The model is applied to analyze capacitor-based pulsed power circuits for experimental railgun system. Extensive simulations have been performed to examine the model characteristics. Also, the factors influencing waveform of discharging current and system efficiency are discussed.
04P-37: Development of Gas-Discharge Lasers Using TPI-Type Pseudospark
Switches P. A. Bokhan1, D. E. Zakrevsky1,
M. A. Lavrukhin1, D. S. Churkin2, A. M. Razhev2, A. A. Zhupikov2, S. K. Vartapetov3, O. V. Gryaznov3, V. D. Bochkov4,
D. V. Bochkov4, V. M. Dyagilev4, V. G. Ushich4 1Institute of Semiconductor Physics SB RAS,
Novosibirsk, Russian Federation 2Institute of Laser Physics SB RAS, Novosibirsk,
Russian Federation 3Physics Instrumentation Center at GPI RAS, Troitsk, Moscow region, Russian Federation 4Pulsed Technologies Ltd., Ryazan, Russian
Federation
The unique powers of TPI-type pseudospark switches have been discovered recently to make them the most promising switches for sub-microsecond range of pulse duration in various applications. They feature high timing stability with jitter of less than 400 ps, high current rise rates up to 10^12 A/s, switching currents of tens kA per units of nanoseconds, capable of delivering high reverse currents. A recovery time of the described switches is less than 1 microsecond, thus providing operating frequency up to hundreds kHz. At that the service time in similar modes is at least not less than for known solid-state switches, but they have lower cost, mush less physical parameters. The TPI-thyratrons are capable of operating completely without heating [1], thus substantially improving performance, simplifying circuit design when operated under cathode high potential (or both cathode and anode), providing instant readiness. The investigations of TPI-thyratrons have been conducted in various accelerators [2], in pulse generators for non-thermal effects on bio-objects, gamma and neutron-ray logging, in corona streamer electrofilters etc. This paper reviews the results obtained by comparative tests of hot cathode thyratrons, trigger spark-gaps versus thyratrons of TPI-series as high-voltage switches in vapor lasers excitation systems (including thallium, copper, metal halide-lasers), excimer (F2, ArF, KrF, XeF, XeCl, KrCl,) chemical (HF) and carbon dioxide lasers. The choice of the switches was motivated by the fact that they combine all advantages of existing fast switches (including pulse thyratrons and solid-state devices) such as high pulse repetition rate, low stored energy losses, short jitter, absence of incandescent cathode, high durability and resistance to failure, high radiation tolerance, low overall dimension. The investigations have shown that TPI-type thyratrons will be the most promising switches for pulse gas lasers active medium excitation. So replacing trigger spark-gaps by PSS in excimer gas-discharge lasers we
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provide higher voltage drop in the discharge laser gap due to lower energy losses in the switch and improve gain into active medium with less energy stored, increase by 30-40 % radiation power and degree of efficiency. The application of TPI-thyratron in laser excitation systems allows to avoid a mounting of additional compression sections (non linear saturated inductances), which simplifies design of the pulse generator, makes it more reliable and cost-effective. By using pseudospark switch TPI1-10k/20 instead of hot cathode thyratron we can switch high frequency pump pulses in active elements of metal-vapor lasers, featuring leading edge of current pulse less than 5 ns and relatively low energy losses, thus making them the most prospective for lasers on self-restraint transitions. [1] 2nd Euro-Asian Pulsed Power Conference, Vilnius, Lithuania, 2008, O4-5. [2] 2007 PPPC, NM, USA, 2007, p.1335 and p.1339.
04P-38: Design and Analysis of Linear Flux-Switching Permanent Magnet Motor
for Electromagnetic Launcher M. Mirzaei1, S. E. Abdollahi2
1Electrical Enginnering, Amirkabir University of Technology, Tehran, Iran
2Electrical Enginnering, University of Tehran, Tehran, Iran
In this paper, design and analysis of linear flux-switching permanent magnet motor for electromagnetic aircraft launch system is presented. The motor performance is similar to the AC machines and the same control system can be used. In the motor structure, permanent magnet and windings are mounted on the stator and moving secondary or shuttle is laminated iron. The robust structure of secondary makes the system more suitable for aircraft launcher. In the previous works for considered application, the magnet is on secondary side which is difficult to control permanent magnet temperature during system work time. This problem has been solved in the proposed structure. For the design of the electromagnetic launcher system two stages is considered. First the produced force of linear motor should be enough to accelerate the aircraft and secondly the mass of secondary (shuttle) is important to brake the shuttle in limited distance after launching of aircraft. The concentrated winding is used in this motor which has less copper losses. Different configurations of primary and secondary are considered to get required thrust force with the less input power or higher efficiency and power factor and also minimum cogging force. The main disadvantage of the linear motor for this application is that whole path of launching (100 m)and braking(10 m) have permanent magnet (for the stator)that makes the system to be expensive. The minimum usage of permanent magnet is another objective of this paper. Current source inverter is used because of high power linear machine. For switching of current in the inverter, the linear machine should have small inductance. Minimum inductance is important parameter during linear flux-switching permanent magnet motor design. The number of required switches and their position during secondary moving is considered. The proposed inverter is designed with taking into account the last advancement of high power and high speed switches and their costs. For magnetic analysis of the linear motor, analytical and numerical methods are used which includes 2D and 3D finite element calculations to compute linear motor performance. End effects in transverse direction of flux switching permanent magnet motors should be taken into account during analysis using 3D finite element analysis. Number of poles and secondary and primary teeth dimensions are optimized with iterative
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analysis and consideration of temperature rise in windings. Thermal calculations are necessary to show the temperature of winding in each takeoff (time interval between two consecutive takeoffs is 45 second). In first design, no cooling is used but using thinner conductors is proposed to reduce the stator or primary size then intensive cooling is needed to decrease temperature rise. Two different configurations of primary (stator) and secondary (inverted U and blade type) are analyzed. The blade shape secondary shows low mass that is very important during braking. But stator is simpler in inverted U structure. The primary structure with minimum usage of permanent magnets can be applied easier for inverted U rather than blade type structure.
04P-39: Compact 200-Hz Pulse Repetition GW Marx Generator System
C. Nunnally, J. R. Mayes, C. W. Hatfield, M. B. Lara, T. R. Smith
Applied Physical Electronics LC, Austin, TX, United States
The compact, wave-erection, GW-class compact Marx generator has been previously reported for 5 ns to sub-ns risetime pulsed power applications. This generator topology has recently been adapted for high Pulse Repetition Frequency (PRF) applications and is the basis for a new high-PRF pulsed power system. The 33-J generator itself is capable of delivering a 300 kV pulse into a matched 33-Ohm load, or 600 kV into an open circuit. The high-PRF system includes an 8 kJ/sec Lambda high-voltage power supply and an APELC trigger and control unit. The APELC trigger/ unit contains a 150-mJ thyratron-based pulse generator and facilitates the synchronous pulse charging of the Marx generator. The trigger unit also provides analog output signals of the thyratron and Marx charging signals and features LED diagnostic and fault indicators on the front panel. Applications of the high-PRF system include sourcing of High Power Antennas. Design considerations, system architecture, and experimental results of the high-PRF pulsed power system are presented in this paper.
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04P-40: Development of a Solid State Versatile Pulsar for High Voltage and
High Power Applications R. Varma, K. S. Sangwan
Industrial Electronics Group, Central Electronics Engineering Research Institute (CEERI)/ Council of Scientific and Industrial Res, Pilani, Rajasthan,
India
Abstract: A solid state pulsar for high voltage and high power application has been developed, fabricated and tested. Provision for independent variation of pulse amplitude, width and repetition rate, make it a versatile source for many pulse power applications and experiments. The basic module is rated for 2.5 KV and 50 amperes. Experimental prototype with 20 series connected modules is used to generate 50 KV pulse. Pulse width variation from 5 to 50 sec and PRF from 1 Hz to 200 Hz have been achieved. Pulses of positive or negative polarity can be generated by changing the earth connection. Tests results on resistive load are obtained and presented in this paper. The pulsar would be used for characterization of high power microwave tubes. REFERENCES: [1] Jong-Hyun Kim; et al; High voltage pulse power supply using Marx generator & solid-state switches; 31st Annual Conference of IEEE Industrial Electronics Society, IECON 2005. Raleigh, North Carolina, USA, 6-10 Nov. 2005. [2] M. Akemoto, et al, Solid State Switching Modulator R&D for Klystron, 5th Modulator-Klystron Workshop for Future Linear Colliders MDK-2001, CERN, PS Division, Geneva, 26-27 April 2001. [3] E. G. Cook; Review of Solid State Modulators; XX International Linac Conference, 21-25 August 2000, Monterey, California, USA. [4] Scharnholz, S., et al; Investigation of IGBT-devices for pulsed power applications; 14th IEEE International Pulsed Power Conference, PPC-2003, 15-18 June 2003; pp349- 352 Vol.1. [5] Gaudreau, M.P.J., et al; Solid state modulator for klystron/gyrotron conditioning, testing, and operation; 12th IEEE International Pulsed Power Conference, PPC-1999, 27-30 June 1999, pp1295 - 1298 vol.2.
04P-41: Efficient Pulsed Power Generation
A. Rahman, M. S. Alam, M. Y. El-Sharkh, N. Sisworahardjo, P. C. Byrne
Department of Electrical and Computer Engineering, Univsity of South Alabama, Mobile,
AL 36688, United States
A highly efficient pulsed power generator is modeled and developed to drive a single-stage plasmoid thruster. The pulsed power generator is characterized by its energy stored in the capacitor. This energy can be released in the form of pulsed power to the thruster coils by means of a fast response switching device. The conventional approaches in pulsed power design results in producing a “ringing” effect due to the back and forth transfer of energy between the capacitor and the coils. A modification of the pulsed power generator design by the introduction of a diode eliminates the ringing and the associated waste of energy. Preliminary results based on the small-scale experimental setup of the proposed technique indicates that the approach is viable and can produce highly efficient repetitive single pulsed power for thruster applications.
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04P-42: Circuit Simulation Analysis of a Vircator Powered by Different High-
Voltage Pulse Sources P. Appelgren, M. Akyuz, M. Elfsberg, T. Hurtig,
C. Moeller, A. Larsson, S. E. Nyholm Swedish Defense Research Agency FOI, Tumba,
Sweden
The high-voltage pulse source is a key component in systems that generate high-power microwave (HPM) radiation. Different types of high-voltage pulse sources have different characteristics and interact differently with the radiation source. This paper presents a circuit simulation study of the interaction between a vircator load and three different high-voltage pulse sources. The voltage pulse sources considered have previously been studied experimentally and they are a Marx generator, a high-voltage system based on a small explosively driven magnetic flux compression generator and a cable generator. The Marx generator has a nominal output voltage of 400 kV (400 J) and has an impedance of 20 Ohms. It has been used in a large number of experiments with an axial vircator [1]. The explosively driven magnetic flux compression generator is capable of delivering over 400 kA into a 0.2 uH inductive load [2]. It can be used in a pulse-conditioning system containing an electrically exploded opening switch to generate the high-voltage pulse and a peaking spark gap to transfer the pulse to the load. The cable generator can deliver a rectangular, flat-top voltage pulse of 500 kV and length 200 ns into a 10 Ohm unmatched load at an electric power of 25 GW [3]. The circuit simulation models have been validated by different experiments. The different voltage sources generates very different pulse shapes, amplitudes and durations and their respective effect on power deposition in, and impedance of, the vircator are discussed. [1] M. Elfsberg, T.Hurtig, A. Larsson, C.Moller, S.E. Nyholm, Experimental Studies of Anode and Cathode Materials in a Repetitive Driven Axial Vircator, IEEE Transactions on Plasma Science, Vol. 36, Issue 3, Part 1, June 2008, pp. 688 – 693 [2] P. Appelgren, G. Bjarnholt, N. Brenning, M. Elfsberg, T. Hurtig, A. Larsson, B. M. Novac, and S. E. Nyholm, Small Helical Magnetic Flux Compression Generators: Experiments and Analysis, IEEE Transactions on Plasma Science, Vol. 36, No. 5, October 2008, pp. 2673-2683 [3] A. Lindblom, A. Larsson, H. Bernhoff and M. Leijon, 45 GW pulsed-power generator, 2007 IEEE Pulsed Power and Plasma Science Conference, Albuquerque, USA (2007)
04P-43: Inductive Energy Storage Modulator Using SI Thyristor
J. Li, M. Watanabe, E. Hotta Dept. of Energy Sciences, Tokyo Institute of
Technology, Yokohama City, Japan
With the increasing needs of non-equilibrium plasmas for deodorization, sterilization and toxic gas decomposition, the high-voltage pulse system is required to have the capability of supplying extremely narrow high-voltage pulses with high repetition rate. For most pulsed power generators, the output power level, the repetition rate and the pulse width are largely determined by the capability of switching units. Among all the available switches, Static Induction Thyristor (SI Thy) has drawn a special attention due to its excellent property in short turn-off time of flowing current and high withstand voltage. By using this SI thyristor, several compact pulsed power generators had been developed, and the repetition rate has been achieved as fast as 3 kHz. In this paper, a simple and compact pulsed high-voltage generator, which has an advantage of high repetition rate, has been developed. It employs inductive energy storage scheme and utilizes an SI Thy as a main opening switch, aided by MOSFETs connected in series. Output amplitude is decreasing gradually with increasing the repetition rate; because the heat produced inside SI Thy will greatly lower the falling rate (di/dt) of interrupted current. In order to obtain better output performance, the improvements in cooling system is necessary. Driven by a DC input voltage of 100 V, it generates pulsed high-voltage output of 28.2 kV with FWHM (full-width at half-maximum) of 128 ns at the repetition rate of 1 kHz. Under the current cooling system, it can stably generate the high-voltage pulses with amplitude of more than 20 kV and FWHM of 164 ns even at the repetition rate of 6 kHz. Experimental results on energy efficiency evaluation will be presented. This work was supported by NGK Insulators Ltd.
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04P-44: Modelling of a Streamer Plasma Reactor Energized by a Capacitive
Energy Pulse Modulator M. Wolf1, Y. Yankelevich1, A. Pokryvailo1,
R. Baksht1, S. Singer2 1Soreq NRC, Yavne, Israel
2Tel-Aviv University, Tel-Aviv, Israel
This paper presents a semi-empirical model for a wire-wire corona reactor driven by a capacitive storage solid state pulse generator. The reactor electrode system is configured as a checker mesh of potential and grounded threaded electrodes, and the pulse generator is based on a modern magnetic compression topology. Both the corona reactor and the nanosecond pulse power supply were described in details earlier [1] [2]. This presentation considers the effect of the geometrical parameters of the reactor (the total length of the high-voltage electrode surrounded by its grounded counterparts and the gap between high-voltage and the grounded electrodes) on the operation of the atmospheric pressure streamer plasma system. The model analyzes the discharge processes in the reactor by distinguishing between four phases, each is represented by an equivalent circuit: before streamer generation, during primary streamer propagation, after primary streamers have crossed the interelectrode gaps, and after the plasma conductivity quenching. Such an approach has previously shown good validity in different kinds of corona reactor and pulse generator [3]. The new reactor model is realized in the PSpice platform and simulations are done using an improved pulse modulator model [4]. The simulation results are compared with experimental data, showing the model validity. [1] A. Pokryvailo, Y. Yankelevich, M.Wolf, E.Abramzon, E.Shviro,S. Wald, and A.Wellemann, "A High-Power Pulsed Corona Source for Pollution Control Applications", IEEE Transactions on Plasma Science, vol. 32, pp. 2045-2054, October 2004 [2] A. Pokryvailo, M. Wolf, and Y. Yankelevich, "Investigation of Operational Regime of a High-power Pulsed Corona Source with an All-solid State Pulser", IEEE Transactions on Dielectrics and Electrical Insulation, 14, n.4, August 2007 [3] G.J.J. Winands, Zhen Liu, E.J.M. van Heesch, A.J.M. Pemen, and Keping Yan. "Matching a Pulsed-Power Modulator to a Streamer plasma Reactor", IEEE Transaction on Plasma Science, 36, N.1, February 2008. [4] M. Wolf, "Investigation and Development of Nanosecond Pulsed Corona Source for Pollution Control Applications", M.Sc. thesis, Tel-Aviv University, Tel-Aviv, Israel, 2009
04P-45: Design and Analysis of a Modified Homopolar Pulsed Generator
M. Mirzaei1, S. E. Abdollahi2 1Electrical Enginnering Department, Amirkabir
University of Technology, Tehran, Iran 2Electrical Enginnering Department, University of
Tehran, Tehran, Iran
In this paper, a pulsed power generator with homopolar structure is presented. The winding and field are on stator side and rotor is only iron. Rotor has two parts, laminated pole shoes and solid shaft. The stator has concentrated windings to increase winding factor and voltage. Two configurations are considered for winding. First tooth winding structure and secondly air- gap winding is proposed. The former one has a simple manufacturing process but higher inductance and the latter has lower inductance and difficult manufacturing process and higher losses and also lower flux density in air- gap with the same exciting current. The main objective in this paper is to show a new configuration of homopolar machine for pulsed power application which can compete with wound rotor pulsed generator but with simpler structure in rotor side. Two parts rotor is proposed to reduce eddy current losses on rotor side using laminated steel. During transient operation of generator, very big eddy currents will flow in solid rotor which attenuates the performance of pulsed generator. Laminated rotor can be an alternative to the solid rotor with consideration of mechanical stress. The high strength and low losses steel lamination M 250-50A (lamination thickness is equal 0.5 mm) is used for rotor. To increase the flux density in the air gap, high permeability steel lamination M 440-35 AP (lamination thickness is equal 0.35 mm because of high frequency) is used for stator. The exciting field winding is hollow conductor to increase the current density and produce more magnetic flux density in the air gap. The speed of the machine has been considered 15000 /min and number of poles at first design is assumed 8. This means the frequency on stator side for the fundamental component is 2000 Hz. The high frequency does not produce high losses because of short duty of pulsed generator. The structure of the rotor is made completely sinusoidal shape to reduce harmonics and losses and produce real sinusoidal voltage. Analytical and numerical methods are used to performance calculations of the machine. First of all due to the high speed, the mechanical stress analysis is done to check the robustness of the rotor against to the centrifugal forces. Magnetic calculations are the second step for analysis of voltage and the current during the generator work and also losses in rotor and stator. Winding losses is one of the main parameters for design. For this purpose, a
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thermal calculation with consideration of transient operation is done to evaluate the temperature rise in the windings.
04P-46: A Semiconductor Switch and Magnetic Switch Based Multi Purpose
Pulsed Power Generator G. H. Rim, J. S. Kim, H. J. Ryoo, Y. S. Jin,
J. H. Cho, Y. B. Kim Industry Applications Research Division, KERI,
Changwon, South Korea
This paper describes a high frequency pulse generator developed for various industry applications such as water, food and medical apparatus sterilization or polluted gas cleaning. The system is made of three blocks. The first block charges capacitors up to 2.8kV which minimized the use of semiconductor switches with the ratings of commercially available device. In the 2nd block one thyristor is in charge of pulse forming 12kA with pulse duration of 9.5 micro-seconds. A pulse transformer MS1 with a ratio of 1:10 transfers energy to charging capacitors in the 3rd block up to voltage of 28kV and saturation of MS1 resulting in compressing pulse width of 1.5 micro-second and the voltage across MS is doubled. And then the linear transformer LT with turns ratio of 1:4 ensures 120kV of output on a matched load of 25Ohms. The parameters obtained through the development are; Output voltage: 120kV max, Pulse repetition ration: 300pps, Pulse width: 0.25uS mean power of 30kW. The Pspice-simulation and experimental results will be reported in the final presentation.
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04P-47: A Klystron Power System for the ISIS Front End Test Stand
M. Kempkes1, K. Schrock1, A. Letchford1, 2, R. C. Ciprian1, T. Hawkey1, M. P. J. Gaudreau1
1Diversified Technologies, Inc., Bedford, MA, United States
2STFC Rutherford Appleton Laboratory, Didcot, United Kingdom
Diversified Technologies, Inc. (DTI) has delivered a fully solid-state Klystron Power System (KPS) for the ISIS Front End Test Stand to Rutherford Appleton Laboratory in the United Kingdom. The KPS consists of a specialized step-up transformer, high voltage, solid-state power supplies, capacitor bank, pulse modulator, and controls. DTI engineered the system to deliver several significant advantages to ISIS including eliminating the need for a large pulse transformer, eliminating the crowbar for greater system availability and klystron reliability, reducing the available arc energy, and simplifying the modanode voltage control. Prime power for the klystron is generated by two high voltage switching power supplies, each capable of producing 220 kW CW power at 110 kV (maximum) with 0.1% regulation These power supplies are combined in parallel to meet the overall system power requirement. A specialized, 400 V to 490 V autotransformer offers a 30 degree phase shift between its two independent outputs, achieving 12-pulse rectification between the supplies, and thus lowering input line harmonics. The system is capable of operating at lower average power if either power supply is off-line. The system is cathode pulsed, which allows mod-anode voltage control by simply adjusting the mod-anode power supply voltage, independent of cathode voltage (unlike a resistive divider). Cathode pulsing also eliminates the need to reverse bias the mod-anode with respect to the cathode, because the beam is fully cut off when the cathode switch is open. This approach eliminates the need for separate push-pull switches on the mod-anode because diodes allow the circuit to operate passively. Specific parameters for the pulse modulator include: cathode voltage -110 kV; cathode current 45 A; PRF 50 Hz; beam pulse width 500 μs – 2.0 ms; droop 5%; and duty cycle 10% maximum. The pulse modulator has, at its core, a stack of ten switch-plates connected in series that provide a maximum voltage standoff of 150 kV. Each switch plate, is rated at a voltage of 15 kV and peak currents of 500 A.
04P-48: Commissioning of the 50 TW Leopard Laser Pulsed Power System
B. Le Galloudec, S. Samek, B. McDaniel, V. Nalajala
University of Nevada, Reno, Nevada, United States
A 50 TW-class short-pulse laser has been developed at the Nevada Terawatt Facility (NTF) at the University of Nevada, Reno. The laser, called Leopard, is a hybrid Ti:Sapphire/Nd:glass system with a commercial front end with rods and disk amplifiers from the former Petawatt laser that was located at the Lawrence Livermore National Laboratory. NTF staff refurbished and used most of the donated equipment to build the pulsed power system that provides electrical energy for the Leopard laser amplification. Also a new Pre-Ionization of Low Energy Circuit (PILC) was designed and installed on the disc amplifier pulsed power system. This new concept is used without additional power supply, as a small part of the energy stored in the capacitors is used to prepare the flash lamps for the main energy discharge.
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04P-49: Optically Monitoring of the Marx Switches to Characterize AWE's Flash X-
ray Machines S. Clough
Pulsed Power Science and Engineering Group/DRAS, AWE, Reading, Berkshire, United
Kingdom
AWE has a number of Single Pulse Forming Line x-ray generators operating at voltages ranging from 1 to 10MV for flash x-ray applications. The Marx banks in these generators are connected to Pulse Forming Lines which comprise of a folded Blumlein and a balance circuit to limit the pre-pulse at the e-beam diode. The first three or four Marx bank switches are electrically triggered and a detrimental charge leakage occurs though the balance circuit during the time taken for the remaining switches to close (Marx erection time). Most critically, this current flow generates a contribution to the pre-pulse voltage level which it is crucial to keep low for optimum x-ray diode operation. This study optically monitored the timing sequence in which the switches of a Marx bank close. The investigation was performed on the EROS simulator which has a 40-150kJ Marx assembled from 66x1.3 microFarad capacitors. Depending on the charge level, the erection time for this Marx increases from 400 to 700ns at its lowest operating voltage. Electrical circuit models were used to interpret the output of electrical diagnostics and these were compared with the results obtained from the optical monitoring.
04P-50: 6-MV Vacuum Voltmeter Development
B. V. Weber1, R. J. Allen1, R. J. Commisso1, D. Hinshelwood1, D. G. Phipps1,
S. B. Swanekamp2 1Plasma Physics Division, Naval Research Laboratory, Washington, DC, United States
2L-3 Communications, Reston, VA, United States
Vacuum voltmeter (VVM) development is reported, with the goal of designing a voltmeter suitable for diagnosing z-pinch loads on the Z generator at Sandia National Laboratories, Albuquerque, NM, where maximum voltages in the -4 to -6 MV range are predicted. A VVM designed [1] to work at voltages up to 2 MV has been used successfully [2] on z-pinch experments on the Saturn generator at Sandia. An extension section was designed and constructed to increase the voltage holdoff to approximately 6 MV. Field shaping structures to avoid electron emission from the VVM grading rings were designed using field plotting programs. The resulting VVM was suitable for fielding on the Mercury generator at NRL to test the performance at voltages up to -6 MV. In situ calibrations with a fast pulser demonstrated the capability for fast (few ns) time response and also showed ringing from stray capacitance of the field shapers. A circuit model using a lossy transmission line representation of the VVM reproduces the calibration data. Four Mercury shots, one at -2 and three at -4 MV peak voltage, were successfully diagnosed with the VVM. Two subsequent Mercury shots at -6 MV were less successful, evidently suffering from insulator flashover and electron emission from the field shapers and the VVM grading rings. The measurements did not follow the voltage waveform calculated from MITL theory after the voltage exceeded about -4 MV. These shortcomings can be overcome for the Z application, using redesigned field shapers for the Z vacuum chamber and making some incremental improvements to avoid electron emission. Numerical simulations of a VVM (using the LSP code) indicate the effect of electron emission from the grading rings and the field shapers on the VVM as used on Saturn. LSP simulations of the Mercury setup will also be presented. Work supported by Sandia National Laboratories, Albuquerque, NM D. P. Murphy, R. J. Allen, B. V. Weber, R. J. Commisso, J. P. Apruzese, D. G. Phipps, and D. Mosher, Rev. Sci. Instrum. 79, 10E306 (2008). 2. D. G. Pellinen and M. S. Di Capua, Rev. Sci. Instrum. 51, Jan. 1980, pp. 70-73.
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04P-51: Design and Test of a Fast Capacitive High Voltage Probe
H. Heo1, S. H. Kim1, S. S. Park1, S. H. Nam2, J. W. Shin2, D. W. Choi2, J. H. So2 1Pohang Accelerator Laboratory, Pohang,Kyungbuk, South Korea
2ADD, Daejeon, South Korea
We designed a fast capacitive high voltage probe for a Marx generator. Since the capacitive probe works on differential mode, we designed also a fast passive integrator to integrate the signals. We tested the probe’s performance by using a simple pulse generator which simulates the Marx generator signals. We calibrated the probe using a calibrated water load which act as a resistive voltage divider. We present and discuss the results of the experiments.
04P-52: Electromagnetic Dot Sensor A. Al Agry, R. A. Schill, Jr., S. Garner,
S. Andersen, K. Buchanan UNLV, Las Vegas, Nevada, United States
The recently patented UNLV Electromagnetic (EM) dot sensor measures the rate of change of the electric flux density and the magnetic flux density at the same point in space simultaneously over time. This single device performs the function of two to four sensors distributed in space. Calibration studies of the dot are presented ultimately leading to a pair of calibration factors.
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04P-53: High Speed (30ps) Transmission Line Current Sensor
J. E. Barth Barth Electronics, Inc., Boulder City, NV, United
States
This paper describes a new accurate wide bandwidth measurements method of fast risetime current flow inside a coaxial transmission line. It provides minimal impedance discontinuity and preserves the high voltage capabilities of the transmission line. Because the current on the inner and outer conductors is exactly the same but of opposite polarity, it can be monitored in either conductor. This method inserts a very short, low value (0.5 ohm or less) tubular film resistor into the outer conductor of a coaxial transmission line. Its skin effect must be minimal so the voltage on the outside resistor surface is the same as that on the inside surface. To prevent external cable current noise pickup, a metal housing is connected to the outer conductors of coaxial lines on both sides of the current sensing resistor. High speed (high frequency) ferrite torrids placed around these coaxial lines isolate the resistor from the shorting effect of the surrounding metal shield. Voltage developed across the resistor would normally cause current flow away from the resistor down the outside of the coaxial lines. High frequency ferrite torrids around the coaxial lines minimize the fastest part of this current flow back along the outside of these coaxial lines. To maintain high speed pulse response the parasitic capacitance across the current sensing resistor must be minimized. This is done by making the inside dimension of the metal shield housing at least three times the diameter of the current sensing resistor and its coaxial connections. The ferrite torrids used to isolate the current flow on the outside of the coaxial lines they have high dielectric constants. Locating ferrite torrids immediately next to the resistor increases the parasitic shunt capacitance across the resistor and to the metal shield which is at ground potential. Using small diameter torrids immediately adjacent to the current sensing resistor minimizes the parasitic capacitance effects of the ferrites. Larger ferrites can then be added behind them to provide isolation to progressively slower parts (lower frequencies) of the measured signal. Increasing the diameter of multiple ferrite torrids further from the resistor is best accomplished with conically tapered ferrites. A small diameter 50 ohm coaxial placed across the current sensing resistor carries the voltage developed across it outside the shielded container. It also uses high speed conically tapered ferrite torrids with the small diameter next to the current sensing resistor.
With both sides of the current sensing resistor isolated from parasitic capacitance, additional coax and ferrite torrids can be added to improve the long time or low frequency response. Additional ferrite torrids with progressively higher permeability (and higher loss at high frequencies) can be added to increase the shunt inductance to whatever is required. Positioned after the ferrites, metal foil torrids can be added to extend the pulse (frequency) range down to KHz response. Detailed photographs of the final construction and pulse response waveforms will be included for the complete paper.
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04P-54: Advances in Fiber Based Faraday Rotation Current Measurements*
A. D. White, G. B. McHale, D. A. Goerz Lawrence Livermore National Laboratory,
Livermore, CA, United States
Fiber-based Faraday rotation diagnostics have been used on dozens of high-current (200 kA - 1 MA) capacitive discharge experiments in the LLNL Pulsed Power Lab at both 635nm and 850nm. This paper discusses recent progress concerning several aspects of Faraday Rotation diagnostic operation, including simplifications to the necessary hardware, advances in data analysis, Verdet constant measurements and comparisons with other published values, and the development of a comprehensive numerical model. Also presented are results from an all-fiber polarization analysis scheme that simplifies the optics and reduces the costs necessary to perform quadrature-encoded Faraday Rotation measurements. *This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
04P-55: Frequency-Domain Characterization of Pulsed Power
Diagnostics* A. D. White, R. A. Anderson, D. A. Goerz Lawrence Livermore National Laboratory,
Livermore, CA, United States
Sensors such as B-dot probes or Rogowski coils are frequently used on experimental pulsed power platforms to measure dB/dt or dI/dt with accuracies limited by the accuracy with which the sensors can be characterized. Using time-domain pulse methods, accurate characterization of such diagnostics relies on a) rigorous characterization of all supporting hardware, b) careful minimization or mitigation of droop or integration error produced when the output is integrated for comparison with a reference waveform, and c) rigor in numerical computation of Fourier transforms and deconvolution, necessary when the sensor exhibits frequency dependence. This paper discusses methods of frequency-domain characterization of pulsed power sensors using vector network analyzer and spectrum analyzer techniques that offer significant simplification and expediency when compared with time-domain methods while improving calibration accuracy. *This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
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04P-56: Compact Soft X-Ray Pulse Radiograph Based on X-Pinch and Low
Scale Fast Capacitor Bank S. Chaikovsky, A. Rousskikh, N. Labetskaya,
A. Fedunin, V. Feduschak, V. Oreshkin, N. Ratakhin, N. Zharova
Institute of High Current Electronics, Tomsk, Russian Federation
X-pinches are two or more thin wires crossed as the letter “X” in the electrode gap. As the current passes through the wires, a hot dense x-ray-emitting plasma is produced at the cross point of the wires. The high space and time resolutions achievable with the X-pinch x-ray sources make them attractive for studies of short-lived low scale objects. The paper presents the results of experiments on a compact (400x400x360 mm) fast capacitor bank with a current amplitude up to 250 kA and a current risetime of 200 ns. The generator load was an X-pinch consisting of four thin tungsten wires. Clear soft x-ray backlighting images of different objects in different spectral ranges were obtained. In the spectral range > 1 keV, the size of the radiation source is not greater than 5 microns and in the spectral range > 10 keV, it is 10 microns. The width of the radiation pulse is 2-3.5 ns for the spectral range < 5 keV. The radiograph is enough compact for transportation it to another laboratory for various experiments.
04P-57: X-Ray Methodics for Local Time-Resolved Diagnostics of Relatively Small
Concentrations of Metal in a High-Absorption Mediums for Definition of
Concentration of Metal Vapors in a High-Current Pulsed Discharge
P. G. Rutberg1, M. E. Pinchuk1, A. A. Bogomaz1, L. A. Shirochin2, M. A. Polyakov2, A. V. Budin1,
S. Y. Losev1 1Institute for Electrophysics and Electric Power of Russian Academy of Sciences, St.-Petersburg,
Russian Federation 2Sant-Petersburg State University of
Telecommunications, St.-Petersburg, Russian Federation
The X-ray diagnostic system for determination of metal vapour concentration in high-current discharge in a high-pressure gas, based on pulsed X-Ray source with hardness of 20-50 keV and X-ray CCD camera was designed. Two samples of nanosecond generators were used - with duration of pulses 10-20 ns and 50 ns. Two types of X-ray tubes - through-target and anticathode - were designed and used. For X-ray through-target tube simulation of electron trajectories in vacuum diode was made. Dense cathode plasma expansion was taken into account and its external sheath has been supposed as source of electrons. For load matching of X-ray tubes with generators of different voltage pulse durations, the analyses of plasma expansion velocity in nanosecond mode was used. Different diode geometries of later sealed-off X-ray tubes were preliminary tested at the mockup with continuous pumping. The voltage, current and X-ray dose on test objects were measured with this mockup. X-ray CCD cameras were used for X-ray registration. Test experimental research on diagnostic of high-current discharge in high-pressure gas with z-pinch geometry was carried out. The parameters of experiments are: dJ/dt~10e9-10e10 A/s, current amplitudes up to 1 MA. Experimental data on spatial metal vapour distribution in discharge gap, provided by electrode erosion, were obtained. The result of experiments show that main part of metal vapours concentrates to the axis of discharge channel.
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04P-58: An Effective Way to Preserve X-Ray Film in the Explosive Experiment at
the Diagnostic Test Bench B. T. Egorychev, A. V. Ivanovskiy, A. I. Kraev,
V. B. Kudelkin, V. V. Chernyshev RFNC-VNIIEF, Sarov, Nizhny Novgorod Region,
Russian Federation
Usually high-power capacitor facilities are used as the sources of pulsed power to study the implosion of the liners. Construction of the high-power capacitor facilities is rather expensive. The explosive magnetic pulsed systems, whose operation principle is based on a compression of magnetic flux due to the use of chemical energy of the explosive, are the alternative sources of pulsed power to conduct similar research. Such systems have been developed and are successfully used at RFNC-VNIIEF. However, the application of the explosive magnetic systems involves the difficulties of preservation of the x-ray films recording the image of an imploding liner in the experiment. It is known that in the explosive experiments a high-power shock-wave is generated and the fragments are scattered both under the effect of the explosive charge and of the expansion of the return current conductor of the liner ponderomotive unit affected by magnetic forces. As a result, before such experiments the experimentalists face the problem of creation of different protection systems providing retention of the data on the X-ray film. The paper describes the method of protection of the X-ray film in the explosive experiment for two channels of registration in the process of study of the quasi-spherical liner implosion at the diagnostic test bench. The elements of the external and of the internal protection of the X-ray film will be demonstrated. The results of testing of the main elements of the X-ray film protection system obtained in the preliminary explosive experiment with a model will be presented. The results of a selection of the intensifying screens according to their sensitivity to shock-waves will be given; the method of mounting of the protection cassettes with the X-ray films will be described. The X-ray images of the liner obtained at the diagnostic test bench in the final explosive experiment with a big amount of explosives will be shown. The obtained results will be analyzed. Comparative efficiency of application of additional protection from the fragments in every registration channel will be demonstrated and the efficiency of operation of the entire system will be evaluated.
04P-59: Influence of Tube Volume on the Measurement Uncertainty of Geiger-
Muller Counters K. Stankovic1, M. Vujisic2
1Institute of Nuclear Sciences "Vinca", Belgrade, Serbia
2Faculty of Electrical Engineering, University of Belgrade, Belgrade, Serbia
GM counters are often used in radiation detection since they generate a strong signal which can be easily detected. The working principal of GM counters is based on the ionization interaction of radiation with atoms and molecules of gases in the counter's tube. Free electrons created as a result of the interaction, present in a counter's tube, become initial electrons, i.e. they start an avalanche process which is detected as a pulse of current. This current pulse is independent of energy imparted in gases, which is the main difference between GM counters and the majority of other radiation detectors. The dependence on incidence radiation energy, tube's orientation and reading system characteristics are labeled in the literacy as the main sources of measurement uncertainty of GM counters. The aim of this paper is to determine the influence of the counter's tube volume on the measurement uncertainty of GM counters. Therefore, the dependence of detecting pulse current formation on the counter's tube size will be considered, in both radial and parallel geometry. Initiation and current pulse developing will be treated through the elementary processes of electrical discharge as Markov processes, while the change of the counter's tube volume will be treated through the space time enlargement law. Random variable "current pulse in the counter's tube" (i.e. electrical breakdown of the electrode configuration) will be considered statistically and based on it, the appropriate theoretical distribution will be determined. Results obtained theoretically will be compared with appropriate experimental results obtained under well controlled laboratory conditions. The parameters varied in the experiment will be ionizing radiation energy and counter's tube orientation with respect to the direction of incidence radiation.
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04P-60: Spectral Penning Ionization Gauge for Early Leak Detection in E-
Beam Foils for Electra: 700 J, KrF Laser R. L. Jaynes1, J. L. Giuliani2, J. D. Sethian2,
F. Hegeler3, A. E. Robson3, A. Magassarian1, M. F. Wolford2, P. M. Burns4
1Science Applications International, Corp., McLean, VA, USA
2Plasma Physics Division, Naval Research Laboratory, Washington, DC, USA
3Commonwealth Technology, Inc., Alexandria, VA, USA
4Research Support Instruments, Lanham, MD, USA
Electra is a 700 J repetitively pulsed (1-5 Hz), electron beam pumped KrF laser for Inertial Confinement Fusion (ICF) research, at the Naval Research Laboratory. The laser gas (gain medium) is pumped by two 500 kV, 100 kA, 140 ns pulsed electron beams. Typically the laser gas is at 20 psi, and consists of 19.5%% Kr, 80% Ar and 0.5% of F2. The e-beam vacuum diode is separated from this laser gas by a 1 mil thick stainless steel foil. A small pinhole in the foil can lead to catastrophic and violent rupture of the foil, causing significant damage to the e-beam cathode. The rupture also hampers determination of the cause(s) of the foil failure. To obviate this problem, the Naval Research Laboratory has developed a new Spectral Penning Ionization Gauge (SPIG) as an early detection system for pinhole leaks in the foil. The SPIG uses a Penning type discharge to create a low pressure plasma in the ambient 1 kGauss magnetic field used to propagate the e-beam. This plasma is then optically monitored with a photodiode and filter to selectively detect the 750/751 nm Argon lines. This enables the SPIG to be species selective: It is very sensitive to laser gas entering the e-beam diode from a leak in the foil, yet effectively discriminates against ambient background gas. The SPIG operates in large magnetic fields, and appears to be immune to intense EMP electrical noise environments. It has a ~30 ms response time to a pinhole, and is inexpensive to implement. The SPIG detector has been used to reliably stop Electra laser runs before damaging arcs can occur. It has also been instrumental in diagnosing foil failure mechanisms, allowing for forensic diagnostics to be run on foils where pinholes are only 100 microns in diameter or smaller. .* Work supported by DOE/NNSA
04P-61: The High Performance Driver for Thyratron Tube
C.Y. Liu Light Source Division/ Power Supply Group,
National Synchrotron Radiation Research Center, Hsinchu, Taiwan
In this paper, design and implementation of a new Thyratron tube driver deployed in NSRRC is described. This driver is capable of delivering Thyratron trigger-pulse with excellent jitter performance, which is smaller than +/-1nS, and the power transfer ratio is efficient. The voltages used to bias Thyratron tube are also included in the design of this driver. It has been tested and proven to be working well in delivering the kicker pulse with excellent stability and reliability.
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04P-62: Multiple Output Timing and Trigger Generator
R. M. Wheat, G. E. Dale ISR Division, Group ISR-6, Los Alamos National
Laboratory, Los Alamos, NM, United States
In support of the development of a multiple stage pulse modulator at the Los Alamos National Laboratory, we have developed a first generation, multiple output timing and trigger generator. Exploiting Commercial Off The Shelf (COTS) Micro Controller Units (MCU’s), the timing and trigger generator provides 32 independent outputs with a timing resolution of about 500 ns. The timing and trigger generator system is comprised of two MCU boards and a single PC. One of the MCU boards performs the functions of the timing and signal generation (the timing controller) while the second MCU board accepts commands from the PC and provides the timing instructions to the timing controller. The PC provides the user interface for adjusting the on and off timing for each of the output signals. This system provides 32 output or timing signals which can be pre-programmed to be in an on or off state for each of 64 time steps. The width or duration of each of the 64 time steps is programmable from 2 us to 2.5 ms with a minimum time resolution of 500 ns. The repetition rate of the programmed pulse train is limited by the summed widths of each of the 64 time steps. This paper describes the design and functions of the timing and trigger generator system and software including test results and measurements.
04P-63: Design and Testing of the High Voltage Capacitor Charger for 150kJ
Pulsed Power Application H. J. Ryoo1, S. R. Jang2, J. S. Kim1, Y.-B. Kim1 1Applied Electrophysic Research Center, KERI,
Changwon, South Korea 2Dept of Energy Conversion Technology,
University of Science & Technology, Daejeon, South Korea
This paper describes detail procedures of testing high voltage capacitor charger for 7kV, 150kJ pulsed power application. The designed high voltage capacitor charger was developed based on current source load resonant converter and its average charging power is 35kJ/s. The various kinds of tesing were performed including normal operating condition and the malfunction condition of the system. The tests for malfunctioning were performed for the case of open during charging, short during charging and misfiring during charging. The charging time of 150kJ is calculated less than 7 seconds and it was experimentally confirmed that it shows very reliable operation even for the fault operating conditions of the system.
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04P-64: Repeatability Analysis in Hv Capacitor Charging Applications
A. Pokryvailo Spellman HV, Hauppauge NY 11788, United
States
Pulse-to-pulse repeatability, R, is an important parameter in capacitor charging applications. It influences stability of various physical processes ranging from lasing to pulsed X-rays to plasma chemistry applications. There is some controversy in the definition of this parameter. Sometimes it can mean short-term, let us say, repeatability in a batch of N consequential pulses, or long-term, often not specified over which period of time. This paper delves into the subject mostly from theoretical standpoint of view; experimental evidence is given in an accompanying paper. It is stated that R depends on the quality of the HV measurement and the ratio of the energy stored in the HV transformer magnetic system, its parasitic capacitance, etc., Erem, to that stored in the output capacitor, Ec. The influence of the second factor is studied on an example of an energy-dosing converter topology. Governing equations were derived, and solutions in a closed form were obtained for the worst case assuming that the converter is shut down at an arbitrary time point. It came clear that an empiric formula R=sqrt(Erem/Ec) is too simplistic to account for the complex electromagnetic processes; it may give hugely overstated values. The theoretical findings are compared with PSpice simulations for the worst case and experimental results obtained with a 20 kJ/s, 10 kV, 1 kHz repetition-rate charger. Remarkably, the short-term repeatability was better, and long-term repeatability was worse than their PSpice and analytically derived counterparts. This pattern is discussed further.
04P-65: A Fusing Switch for Fault Suppression in the SNS High Voltage
Converter Modulators* M. Kemp1, C. Burkhart1, M. Nguyen1,
D. E. Anderson2 1Power Conversion Department, SLAC National Accelerator Laboratory, Menlo Park, CA, United
States 2Oak Ridge National Laboratory, Oak Ridge, TN,
United States
The High Voltage Converter Modulators (HVCMs) at SNS have operated in excess of a combined 250,000 hours [1]. There are several modulator configurations with up to 1 MW average power, 120 kV output voltage, and 11 MW peak power. Output pulses are ~1.3 ms with a pulse repetition frequency of up to 60 Hz. Performance and reliability improvements to the HVCM are ongoing to increase modulator availability as accelerator system demands increase. SLAC has participated in this effort, redesigning a particularly sensitive part of the modulator, the H-bridge switch plate. Improvements have included an advanced gate drive system and incorporation of press-pack IGBTs [2, 3]. Depending on the nature of the fault, recovery time from H-bridge failures in the HVCMs can significantly decrease modulator availability. The primary energy storage in the modulators is very large, over 130 kJ. During unsuppressed fault conditions such as shoot-through or transformer primary arcs, a significant portion of the stored energy dissipates in the two IGBTs in conduction. This can result in fragmentation of the IGBTs and collateral damage. Partial mitigation of these faults includes SLAC’s contribution of a fast di/dt detection gate drive which has demonstrated, in controlled experiments, the ability to quickly detect and suppress faults. In addition, press-pack IGBTs, utilized in a redesigned H-bridge, do not fragment during faults as do more conventional devices. Even with the above mentioned improvements, it is desirable to quickly isolate the primary energy storage from the H-bridges before a fault results in collateral damage. SLAC has developed the concept of a “fusing” switch to accomplish this task. The introduction of additional switches into the existing HVCM systems has several design challenges. First, physical placement of any additional elements is constrained by already existing hardware. Second, any alteration of existing bus bars must take into consideration any potential inductance increases. The existing modulator was developed to minimize the inductance between the primary energy storage and the H-bridges; changes to this inductance profile may significantly alter performance. Finally, issues such as the appropriate fault
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detection scheme, switch losses, and ease of maintenance are important design parameters. This paper will detail the design for this fusing switch. [1] W. A. Reass, et al., “Design, Status, and First Operations of the Spallation Neutron Source Polyphase…”, PAC, 2003. [2] M.A. Kemp, et al., “Redesign of the H-Bridge Switch Plate of the SNS High Voltage Converter Modulator”, PAC, 2009. [3] M.N. Nguyen, et al., “Advanced IGBT Gate Drive for the SNS High Voltage Converter Modulator”, PAC, 2009. *Work supported by the Department of Energy under contract No. DEAC02-76SF00515.
04P-66: Optimal Design of a Two Winding Inductor Based Bouncer Circuit
D. Bortis, J. Biela, J. W. Kolar ETH Zurich, Zurich, Switzerland
In many pulsed power applications the flatness of the output pulse is an important characteristic to enable proper system operation. Mostly a pulse flatness of less than 1% has to be achieved. In power modulators based on capacitor discharge, the voltage droop is mainly defined by the size of the input capacitance, which in this case has to store more than 50 times of the pulse energy. Therefore, on the one hand the capacitor bank will get bulky and expensive, and on the other hand a lot of energy is stored in the system, which could be a problem concerning safety aspects during a system fault. Additionally, in case of a transformer based power modulator the magnetizing inductance leads to a voltage droop, which not even can be compensated by increasing the storage capacitance. In order to overcome this problem, in power modulators systems compensation circuits are added, whereby in spite of a smaller storage capacitor a flat pulse top is achieved. Depending on the pulse duration, different approaches for voltage droop compensation exists. For long pulse modulators based on multi-stage modulators, like Marx-generators, the voltage droop can be incrementally corrected by successively turning on additional stages during the pulse. Another possibility is to add a switched mode power supply to the modulator, which compensates the voltage droop. Due to the high resulting switching frequency for pulse durations in the range of several μs, a switched compensation circuit is no longer suitable. Therefore, passive solutions or bouncer circuits are more applicable. The LR-network is the simplest way to compensate the voltage droop. Hence, the losses can become significant. Alternatively, with the bouncer circuit, which is a resonant LC-circuit, a pulse flatness of ±0.5% over several μs to ms can be achieved. Thereby, the bouncer produces a linear increasing voltage and compensates the voltage droop of the storage capacitor. However, usually the bouncer is connected in series to the main pulse generation unit and therefore the resonant bouncer has to carry the full pulse current. Additionally, for transformer based power modulators, where a low primary voltage is used (e.g. 1000V), the voltage across the bouncers switch is not adequate for existing semiconductors. Even if the bouncer circuit is placed on the secondary of a transformer the voltage droop, which has to be compensated, would not be suitable for modern power semiconductors. In this paper a two winding inductor based bouncer circuit is presented, which allows to
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adapt the voltage and current rating of the bouncer circuit to the existing semiconductor switches, like IGBT-modules. Due to the realized galvanic isolation a new degree of freedom is achieved, which enables an optimal design of the bouncer circuit regarding voltage and current ratings of the employed semiconductors. Although, the two winding inductor based bouncer circuit is introducing additional parasitics, like leakage inductance and distributed capacitance, it can be shown, that due to the small step up ratio no noticeable degradation of the pulse performance can be observed.
04P-67: Transient Behavior of Solid State Modulators with Split Core Transformer
D. Bortis, J. Biela, J. W. Kolar Power Electronics Laboratory, ETH Zurich,
Zurich, Switzerland
Solid state pulse modulators employed in medical, radar or accelerator applications typically can be classified in three basic topologies: multi-cell-type generators (Marx-generator) [1], direct switched modulators [2] or transformer based modulators [3]. In these circuits the achievable rise and fall times of the pulses are mainly determined by the parasitic elements (capacitances and inductances) in the power circuit starting from the capacitor bank and ending at the load. There, with all three circuits basically similar rise and fall times can be achieved, as will be explained in the paper. For pulse transformers based modulators relatively simple and existing low voltage semiconductor technology can be employed (for example power modules used in traction applications), because the turns ratio of the pulse transformer can be adapted to the current and voltage ratings of existing power semiconductors. Moreover, a series connection of switching elements with the critical voltage balancing could be avoided. For increasing the pulsed power of such system the switches on the primary side of the transformer have to be connected in parallel. There, the current balancing between the parallel connected switches is the main challenge, which could be achieved by active gate control and current/voltage edge measurement as shown in [4]. A major factor, which influences the transient voltage/current distribution, are parasitic elements of the transformer as will be explained in this paper. There, the focus is put on split core transformers, which offer superior pulse rise and fall times, and the relation between the different parasitic elements and the current/voltage edges is discussed in detail as well as measurement results are presented. In addition, also soft turn off conditions of the switches, which are achieved with the parasitic capacitances of the transformer, are discussed and also measurement results are shown. [1] R.L. Cassel, “An all Solid State Pulsed Marx Type Modulator for Magnetrons and Klystrons,“ Record of the IEEE Pulsed Power Conference, Page(s): 836-838, Jun. 2005. [2] M.P.J. Gaudreau, J.A. Casey, T.J. Hawkey, J.M. Mulvaney and M.A. Kempkes, “Solid-state pulsed power systems,“ Record of the 23rd International Power Modulator Symposium, Page(s): 160-163, Rancho Mirage CA (USA), 1998. [3] J. Biela, D. Bortis and J. W. Kolar, “Modeling of Pulse Transformers with Parallel- and Non-Parallel-Plate Windings for Power Modulators,“
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IEEE Transactions on Dielectrics and Electrical Insulation, Vol. 14, Issue 4, Page(s): 1016-1024, Aug. 2007. [4] D. Bortis, J. Biela, J.W. Kolar, “Active Gate Control for Current Balancing of Parallel-Connected IGBT Modules in Solid-State Modulators” IEEE Transactions on Plasma Science, Volume 36, Issue 5, Oct. 2008 Page(s):2632 – 2637.
04P-68: A Vernier Regulator for ILC Marx Droop Compensation
T. Tang, C. Burkhart, J. Olsen Power Conversion Department, Stanford Linear Accelerator Center, Menlo Park, United States
The ILC Marx modulator generates 1.6 ms, 120 kV, 140 A, pulses at a repetition rate of 5 Hz to power a 10 MW L-band klystron. The output voltage must be regulated to ±0.5% to maintain RF phase stability; however, without compensation, it would drop by over 40% as the energy storage capacitors discharge. A 2-part compensation scheme, Vernier Regulation, is used to offset this droop. Coarse correction, ±5%, is achieved with five additional Marx cells (Delayed Cells) that are turned on sequentially as the droop reaches the cell voltage (11 kV). The required additional correction is produced by a small Marx in series the output. This Vernier Marx is composed of sixteen, 1200 V cells that are assembled as a seventeenth cell in the ILC Marx. These Vernier cells are turned on sequentially to generate a stair-step correction to the droop in the main Marx cells. As the required correction reaches 11 kV, all vernier cells are turned off synchronously with the turn on of the Delayed cell. There are six Vernier Marx cycles during each ILC Marx output pulse. The Vernier Marx has a local control system which will detect and handle over-voltage and over-current errors. In this paper, a detailed description of the design, implementation and testing of the regulator is presented.
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04P-69: Comparative Evaluation of Isolated Medium Voltage DC-DC
Converter Topologies for Recharging the Energy Storage of Pulsed Power
Systems G. I. Ortiz, D. Bortis, J. W. Kolar ETH Zurich, Zurich, Switzerland
In most pulsed power applications, isolated DC-DC converters are use to deliver the needed amount of energy for recharging the storage tank of the pulse modulator. Commonly, the power supply, consisting of a three-phase rectifier followed by an isolated DC-DC converter, interconnects the pulsed power system directly to the three-phase mains. There, in order to fulfill the tight harmonics standards, the three-phase rectifier has to achieve unity power factor and/or a continuous power with sinusoidal currents has to be drawn from the three-phase mains. Additionally, in order to facilitate a wide applicability, the line-to-line voltage from 177V to 527V has to be covered. Finally, depending on the modulator topology, an isolated DC-DC converter connected to the rectifier output has to provide a high output voltage for recharging the energy storage tank to the desired operating voltage. Numerous isolated DC-DC topologies, like the classical flyback converter, the isolated full-bridge converter with full wave output rectifier, the isolated full-bridge boost converter with active clamp or resonant converters, have been proposed in the literature for energy delivery to pulsed power systems. There, each topology has its specific advantages, like a low number of power semiconductors, simple controllability, low switching losses or small overall volume or specific requirements as, e.g., for the flyback converter a low transformer leakage inductance has to be ensured, meanwhile for the isolated full-bridge converter the leakage inductance is required for defining the power transfer. In the literature so far no comparative evaluation of different isolated DC-DC converter topologies for pulsed power applications has been performed. Therefore, in this paper, existing isolated DC-DC converter topologies for supplying pulsed power systems are compared, whereas the advantages and disadvantages of each converter topology are highlighted. Afterwards, the most suitable converter topology to supply a 11kW, 3.5kV pulsed power system is analyzed in detail, considering the number and required ratings of the semiconductors, the design and construction of the high voltage transformer concerning volume, core material and winding topology. When needed, the magnetic integration of series inductances into the transformer will be addressed. Additionally,
other features as the voltage/current balancing between the series connected diodes of the high voltage rectifier, the sensitivity to changes in the operating conditions, the power losses, the overall volume and the control complexity of the DC-DC converter will be analyzed. Finally, the paper is concluded with experimental results of the realized 11kW, 3.5kV isolated DC-DC converter.
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04P-70: A 432-kW Peak Power Solid-State Resonant Link Power Modulator System*
N. Schoeneberg, D. Szenasi, M. Coblentz, C. Lors, W. Drumheller, K. Jansen,
C. Manzanares, V. Gorodetsky, R. Jolin, B. Childress, D. Barrett
High Power Solutions Division, Science Application International Corporation, Manassas,
Va./Albuquerque, N.M, United States Science Applications International Corporation (SAIC) has designed, built, tested, and delivered a high power solid-state modulator system which is capable of driving multiple loads. This system consists of a number of stand-alone 432-kW peak, 108-kW average power individual modulator units based upon SAIC’s Dual Resonant Link technology. Each individual modulator unit employs a specially developed control system which provides full digital control with 10-ns switch resolution, 12.5-MHz on-board sampling, and provides a 2 to15-kHz switching frequency to the modulator circuitry. The combination of the Dual Resonant Link topology, a fully-modeled control algorithm, and the high-speed control hardware gives an individual modulator unit the capability of providing a constant, current-controlled output of up to 36-kV at 12-A (2% ripple) for a full 50-ms pulse width, while allowing for a maximum droop of 30% of the nominal 575-V input voltage. Individual control of each modulator unit is provided to accommodate varying requests of output current (3 to 13-A), pulse width (1 to 50-ms), rep rate (single shot up to 5-Hz), and current rise time (down to 200-µs). Additionally, multiple modulator units can be operated synchronously with tight unit-to-unit jitter. The input-to-output efficiency has been measured at 89%. The volume and weight of an individual modulator unit are 8-ft3 and 760-lbs, respectively, yielding volumetric and gravimetric peak power densities of 54-kW/ft3 and 0.57-kW/lb, respectively. The design can accommodate 60oC ambient air and water temperatures and MIL-STD shock and vibration profiles. Finally, one of the key features of this specific design is the line replaceable unit (LRU) arrangement of the four subassemblies, each of which can be replaced in under 30-minutes. ______________ * This work supported by Air Force Research Laboratory, Directed Energy Directorate, Kirtland Air Force Base, N.M.
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O21: Industrial, Commercial, & Medical Applications
Colonial
Thursday, July 2 15:00-17:00
O21-1: Scalable, Compact, Nanosecond Pulse Generator with a High Repetition Rate
for Biomedical Applications Requiring Intense Electric Fields
J. M. Sanders, A. Kuthi, Y. H. Wu, P. T. Vernier, C. Jiang, M. A. Gundersen
Electrical Engineering - Electrophysics, University of Southern California, Los Angeles, CA, United
States
A high repetition rate, high voltage pulse generator has been developed that scales up the output voltage of a recently reported ultra-compact, nanosecond pulse generator that is currently being used in various biomedical applications, including experiments into the mechanisms that drive cellular electropermeabilization and plasma generation for an endodontic disinfection tool [1, 2]. The single-stage, nanosecond architecture upon which this new pulse generator is based is composed of a bank of power MOSFETs, a linear network of inductors and capacitors, and a bank of junction recovery diodes; it was reported to feature an output pulse amplitude voltage to input voltage ratio between 5 and 6 [3]. Since commercially available power MOSFETs with sufficiently high current ratings tend to be limited to 1 kV, the output amplitude of the single-stage pulse generator cannot exceed 5 or 6 kV. To combat this limitation, two different architectures have been developed that enable scaling of the output voltage. The first of these increases the voltage input to the pulse-forming network by means of a solid-state Marx bank that employs power MOSFETs arranged in a series-parallel arrangement to handle the high voltage and high current requirements of the switching stage. The second architecture also makes use of a Marx bank to increase the input voltage, but it relies upon a saturable transformer to handle the high current. Each of these has its own advantages: the first architecture is capable of producing low-jitter pulses with a linear input-output voltage relationship; whereas, the architecture with a saturating core features fewer components and reduced complexity. Prototypes of both architectures have been designed, built, and tested, and they are currently being used. A finalized system based on the saturable transformer architecture is being built that will deliver nanosecond pulses with 10 kV amplitudes into 50 Ohm, with anticipated design limits of 25 kV or higher. [1] P. T. Vernier, Y. Sun, and M. Gundersen, "Nanoelectropulse-driven membrane perturbation
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and small molecule permeabilization," BMC Cell Biology, vol. 7, p. 37, 2006. [2] C. Jiang, M. Chen, C. Schaudinn, A. Gorur, P. T. Vernier, J. W. Costerton, D. E. Jaramillo, P. P. Sedghizadeh, and M. A. Gundersen, "Pulsed Atmospheric-Pressure Cold Plasma for Endodontic Disinfection," IEEE Trans. Plasma Sci, April 2009 [3] J. Sanders, A. Kuthi, and M. A. Gundersen, "Nanosecond Pulse Generator with Scalable Pulse Amplitude," in IEEE International Power Modulators and High Voltage Conference, Proceedings of the 2008, 2008, pp. 65-68.
O21-2: Pulsed Power for a Dynamic Transmission Electron Microscope*
W. J. DeHope, N. D. Browning, G. H. Campbell, E. G. Cook, W. E. King, T. B. LaGrange,
B. J. Pyke, B. W. Reed, R. M. Shuttlesworth, B. C. Stuart
Lawrence Livermore National Laboratory, Livermore, CA, United States
Lawrence Livermore National Laboratory (LLNL) has converted a commercial 200kV transmission electron microscope (TEM) into an ultrafast, nanoscale diagnostic tool for material science studies. The resulting Dynamic Transmission Electron Microscope (DTEM) has provided a unique tool for the study of material phase transitions, reaction front analyses, and other studies in the fields of chemistry, materials science, and biology. The TEM's thermionic electron emission source was replaced with a fast photocathode and a laser beam path was provided for ultraviolet surface illumination. The resulting photoelectron beam gives downstream images of 2 and 20 ns exposure times at 100 and 10 nm spatial resolution. A separate laser, used as a pump pulse, is used to heat, ignite, or shock samples while the photocathode electron pulses, carefully time-synchronized with the pump, function as probe in fast transient studies. The device functions in both imaging and diffraction modes. A laser upgrade is underway to make arbitrary cathode pulse trains of variable pulse width of 10-1000 ns. Along with a fast e-beam deflection scheme, a "movie mode" capability will be added to this unique diagnostic tool. This talk will review conventional electron microscopy and its limitations, discuss the development and capabilities of DTEM, in particularly addressing the prime and pulsed power considerations in the design and fabrication of the DTEM, and conclude with the presentation of a deflector and solid-state pulser design for Movie-Mode DTEM. *This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory and was supported by the Office of Science, the Office of Basic Energy Sciences, the Division of Materials Sciences and Engineering, and the U.S. Department of Energy under contract No. DE-AC52-07NA27344.
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O21-3: High Power UV and VUV Excilamps and Their Applications
V. F. Tarasenko, S. M. Avdeev, M. V. Erofeev, M. I. Lomaev, E. A. Sosnin, V. S. Skakun,
D. V. Shitz High Current Electronics Institute, Tomsk,
Russian Federation
In the present paper, the review of the basic results obtained at the Laboratory of Optical Radiation at High Current Electronics Institute SB RAS during 2007-2008 years is presented. Efficient radiation of Ar2, Kr2, Xe2, KrBr*, KrCl*, XeI*, XeBr*, XeCl*, Cl2* molecules and I atoms was obtained in rare gas or in rare gas - Br2 (Cl2, I2) mixtures. Study of radiation parameters and lifetime period of the manufactured barrier discharge excilamp has been performed. Average power of radiation for the just sealed off KrCl (222 nm) excilamp exceeded 100 W was obtained. UV output power of 75 W and efficiency of 10 %, respectively, at L= 308 nm (XeCl* excilamp) were obtained under excitation by pulses with frequency of 100 kHz. The lifetime of gas mixture in small XeCl* barrier discharge excilamps over 3000 hours was demonstrated. VUV output power of 120 W at L= 172 nm was obtained under excitation by pulses with frequency of 100 kHz. Dynamics of discharge formation in KrCl excilamp has been studied. It has been shown that transition to stationary stage of discharge (in the form of separate microdischarges consisting from two cones with connected tops) takes place within one second as four stages with different discharge forms. Before formation of the stationary fourth stage of discharge, which has the highest efficiency of radiation, the spark stage of discharge is registered during which the bright branchy channels (sparks) are observed. It is supposed that discharge transition from spark to diffuse discharge is determined by formation of runaway electrons in the gap. An efficient low-pressure sealed-off cylindrical excilamp with capacitive discharge excitation is under discussion. Investigation was carried out on the characteristics of XeCl (L ~ 308 nm), XeBr (L ~ 282 nm), KrCl (L ~ 222 nm) and XeI (L ~ 253 nm) capacitive discharge excilamps. High efficiency of exciplex molecules and simple design were obtained under capacitive HF discharge excitation. The lifetime of gas mixture in KrCl*, XeBr*, XeCl*, XeI* capacitive discharge excilamps over 3000 hours was demonstrated. Investigations of radiation of inert gases with haloids excited by high voltage pulses was carried out in the operating mixtures pressure range of 60–750 Torr at various inert gas/halogen. The highest pulsed power densities of KrCl*, XeCl*, XeBr*, and KrBr* molecules
radiation were 3.7 kW/cm2, 3.1 kW/cm2, 4.5 kW/cm2, and 2.1 kW/cm2 at the efficiencies 5%, 4.8%, 5.5%, and 4%, respectively. Work supported by ISTC, project #3583p
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O21-4: ADRE-Plasma Processing of Solid State Surface
A. N. Maltsev1, I. R. Arslanov2, S. N. Garagaty2, A. Y. Ivanov2, D. Y. Kolokolov2, I. N. Lapin2,
V. V. Chupin2 1Institute of Atmospheric Optics Russian Academy of Sciences, Tomsk, Russian
Federation 2Electrodinamic Systems & Technologies, LLC,
Tomsk, Russian Federation
Solid state surface plasma processing technologies are at present actively implemented in great number of industries including microelectronics, textile finishing, polymeric films production, etc. Plasma processing of solid state surfaces is developed worldwide in two directions: 1) the low pressure glow discharge application, and 2) the atmospheric pressure discharge of one of various types (corona, dielectric barrier, high-frequency, etc.) application. Installations for low pressure glow discharge processing have several fundamental lacks. The atmospheric pressure discharges are considered now as the promising solid state surface plasma processing technology. There are several companies produced plasma processing installations on the base of DBD, corona, and jet type atmospheric discharges. However it turns out that the main parameter of all known atmospheric electric discharges is practically similar - all of them have the average energy of electrons about several electronovolts only. But more high electron energy need many plasma technologies for destruction of atom coupling in molecule, etc. For overcoming of this basic problem of standard atmospheric discharges the «Electrodynamic Systems & Technologies», LLC (Tomsk, Russia, [1]) had developed and patented [2] the absolutely new type of the Atmospheric Discharge with Runaway Electrons (ADRE), and also - the unique technology of solid state surface processing [3] on the base of ADRE with big cross section of plasma – about 1500 cm2 for one electrode unit. The ADRE generates in atmospheric air a big number of runaway electrons with energy of many tens of keV. These electrons can penetrate up to tens of centimeters in air and up to 100-200 micrometers into solid state surface. The runaway electrons provide the homogeneity of ADRE and high efficiency of plasma technologies need high energy electrons. Three types of ADRE-plasma processing installations are developed: chamber type processor “Hygeia”, conveyor type processor “Artemis”, and film type material processor "Hermes". The "plasma tunnel" dimensions are the following: the width can be up to 2000 mm; the height - up to 60 mm. The plasma average energy of one module is 1 kW. Our experiments had shown the ADRE surpasses many times all
existing atmospheric discharges in efficiency of different surface sterilization and activation. The ADRE-processing technology developed by “EST”, LLC allows the following: •to sterilize many solid states surfaces in several seconds, •to change purposefully a wettability, and adhesion of polymeric material surface, •to raise capillarity of natural and synthetic fabrics to improve their dyeability, •to reduce the cockle and felting ability of woollen fabrics. The ADRE can be easily built into industrial conveyors. References 1. www.edynamicst.com 2. A. N. Maltsev, “Fast electron, ion, atom, UV and X-Ray radiation beams, as well as ozon and/or other chemically active molecules generation in dense gases”, Patent # 2274923 of Russian Federation, with priority since September 01, 2003. 3. A. N. Maltsev, “Dense Gas Discharge With Runaway Electrons as a New Plasma Source for Surface Modification and Treatment”, Transactions on Plasma Science, vol. 34, issue 4, pp. 1166-1174
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O21-5: Optimization of Reactor Dimensions for Air Pollution Control by
Pulsed Power Discharges T. K. Sindhu, M. Manju, D. Kavitha,
S. Selvakumar Electrical and Electronics Engineering, Amrita
Vishwa Vidya Peetham, Coimbatore, Tamil Nadu, India
Electrical discharge methods are widely being used for air pollution control. Pulsed power methods have the advantages of having higher efficiency due to lower heating effect. The effectiveness of the removal of pollutants depends on various parameters such as magnitude, waveshape and polarity of the applied voltage, field strength inside the reactor, gas flow rate, residence time etc. It is well known that the removal of the pollutants using corona discharge is by chemical reactions between radicals generated and the pollutant gas molecules. The rate of chemical reactions depends upon the mean free path of the medium apart from the energy of electrons and hence the flow rate and residence time. In this study, the aim is to study the reaction rate for reactors of different diameter, shape and for different amount of gas inside the chamber. Also the effect of size of inner electrode on the number of electrons emitted is studied. The reaction rate is calculated using gas kinetic theory and the theoretically obtained results are presented. The efficiencies of dielectric barrier discharge and corona discharge reactors are compared theoretically.
O21-6: A Compact Underwater Shock Wave Generator Using Magnetic Pulse
Compression Circuit for Medical Applications
S. Iwasaki, D. K. Kang, S. Nakamitsu, S. H. R. Hosseini, T. Sakugawa, H. Akiyama Graduate School of Science and Technology,
Kumamoto University, Kumamoto, Japan
Paper reports on production and focusing of micro-underwater shock waves for medical applications. Shock wave focusing has various scientific, industrial and medical applications. For precise shock wave therapies near sensitive organs, such as cranioplasty in the close vicinity of the brain, a micro-shock wave source is required. A half-ellipsoidal cavity with 20.0 mm minor diameter and the ratio of major to minor diameters of 1.41 was designed and constructed as an extracorporeal shock wave (ESW) source. Underwater shock waves were generated by electric discharge produced by a magnetic pulse compression circuit (MPC) and an electrode. Input voltage and input current were measured by using an oscilloscope and a current monitor. The whole sequences of the shock wave generation, propagation, and focusing were visualized by time-resolved high speed shadowgraph method. Pressure histories were measured at different stand-off distances by using a PVDF needle and a fiber optic probe hydrophones. A wide range of peak overpressures from 3.0 to 20 MPa at the focus were obtained, and small focal zone and focal energy flux density were measured. It is concluded that the present compact extracorporeal shock wave generator has appropriate characteristics for application in precise and sensitive medical procedures.
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O21-7: Novel Atmospheric Pressure Non-Thermal Plasma Needle for Selective
Killing of Melanoma Cell T. M. DiSanto, J. L. Zirnheld, B. Onyenucheya,
K. M. Burke Energy Systems Institute, University at Buffalo,
Buffalo, NY, United States
A novel atmospheric pressure non-thermal plasma needle has been developed as a potential cancer treatment instrument. The device operates within a frequency range of 80-100 kHz with the plasma sustaining electrode at a potential of approximately 600V. The plasma in generated by ionizing Helium gas with flow rates in the range of 1-9.7 L/min. Premetastatic and metastatic cell lines as well as Human Primary Keratinocytes (HEK) were treated inside an inverted microscope chamber. Time lapse photography was utilized to captured cell death. Preliminary results have shown selective killing in the premetastatic and metastatic melanoma cells and will be discussed.
O21-8: An Ultra-Portable Marx Generator-Based Solution for MIL STD 461E/F RS-
105 Testing J. R. Mayes, M. B. Lara, W. C. Nunnally,
M. G. Mayes, J. Dowden Applied Physical Electronics, L.C., Austin, Texas,
United States
A Transverse Electro Magnetic (TEM) test cell is designed and implemented for EMP testing implementing the test standard RS-105, under MILSTD 461E/F. The ultra portable system is designed to test electronic closures with high electric field pulses, from 10 – 60 kV/m. An autonomous Marx generator was designed with an integrated pulse forming network to drive the parallel plate transmission line to meet the 1.5 – 2.5 ns rise time and the 18 – 25 ns full width half maximum pulse width requirements. The generator compactly integrates all necessary functions, including the prime battery source, the high voltage DC/DC converter, a high voltage trigger generator, and pressure regulation. A fiber optically-connected hand held controller provides standoff operation. The design of the TEM structure considers the inherent wave dynamics of bounded and free waves propagating the line, and the necessary loading implementation to mitigate reflections back into the test region. This paper describes the concept and design, with experimental results presented to complete the discussion.
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O22: Bulk Optical Switches and Components
Ballroom
Thursday, July 2 15:00-17:00
O22-1: GaN and 6H-SiC Photoconductive Switches
J. S. Sullivan Lawrence Livermore National Laboratory,
Livermore, CA, United States
High voltage, extrinsic photoconductive switches have been fabricated from 400 um and 1 mm thick, vanadium compensated 6H-SiC and iron compensated GaN. These switches are constructed using opposing electrodes allowing trigger illumination through the side facets. The 6H-SiC and GaN devices have been switched using 532 and 1064 nm wavelength light from a q-switched Nd:YAG laser. Holdoff voltages and switch currents of greater than 10 kV and 300 A have been achieved. Switch closing times of < 1 ns have been obtained. These devices have been operated with average electric fields of tens of megavolts per meter in the bulk material.
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O22-2: Solid-State High-Voltage Crowbar Utilizing Series-Connected Thyristors
J. F. Tooker, P. Huynh, R. W. Street Fusion Energy Research, General Atomics, San
Diego, CA, United States High-voltage (HV) crowbars in HV power supplies can often be found in assemblies that are constructed by using series ignitrons or HV switch tubes. They are normally connected across the output of the HV power supplies to protect the load, such as a gyrotron, tetrode, etc., in the case of a HV load fault. Solid-state HV crowbars are now in development. Presented in this paper is one being developed by General Atomics that has thirty SCRs connected in series to withstand a normal operation voltage of 100 kVdc. The SCRs are triggered at the same time to their full conduction in less than 5 microseconds starting from the time when the crowbar receives the signal to fire. The selected SCRs are capable of turning-on in approximately 2 μs with a current rise of 1.2 kA/μs. The crowbar assembly can be set up to operate in either positive or negative polarity. In a typical application, simulations show that the crowbar can limit the energy into a load fault to less than four joules. The electrical design will be discussed including selection of the SCRs. For the mechanical design, both positive and negative assemblies will have the same dimensions and the same components, but the SCRs are installed in opposite directions. The estimate dimensions of the crowbar assembly are 46 in. H x 13 in. W x 13 in. D. The crowbar assembly is to be constructed and electrical tests will be performed, the results of which will also be presented. These tests are to demonstrate a solid-state crowbar to replace ignitron-based designs. The use of ignitrons is being limited and may not be usable in the near future due to environmental concerns. The design has focused on triggering speed, limiting the on-state voltage drop, fast rate-of-rise of current, ease of adaption to different voltage levels and polarities, and the high voltage electrical and mechanical aspects of the design. This work was supported by General Atomics Internal Funding.
O22-3: Pulsed and DC Charged PCSS Based Trigger Generators
S. F. Glover1, F. J. Zutavern1, M. E. Swalby1, M. J. Cich1, G. Loubriel1, A. Mar1, F. E. White2
1Sandia National Laboratories, Albuquerque, NM, United States
2Ktech Corporation, Albuquerque, NM, United States
Prior to this research, we have developed high-gain, GaAs, photoconductive semiconductor switches (PCSS) to trigger 50-300 kV high voltage switches (HVS). We have demonstrated that the PCSSs can trigger a variety of pulsed power switches operating at 50-300kV: two types of DC-charged trigatrons and two types of field distortion mid-plane switches, including a ±100 kVDC switch produced by the High Current Electronics Institute used in the linear transformer driver. The lowest rms jitter obtained from triggering a HV switch with a PCSS was 100 ps from a 300 kV pulse-charged trigatron. Specifically, PCSS are the key component in independently timed, fiber-optically controlled, low jitter trigger generators for HVSs. Trigger generators are critical sub-systems for reliable, efficient pulsed power facilities, because they control the timing synchronization and amplitude variation of multiple pulse forming lines that combine to produce the total system output. Future pulse power systems are even more dependent on triggering, as they consist of many more triggered HVSs and produce shaped-pulses by independent timing of the HVSs. Pulse shaping through timing of the switches results in switch performance requirements that extend over large operating ranges. As pulsed power systems become more complex the complexity of the associated trigger systems also increases. One means to reduce this complexity is to allow the trigger system to be charged from the main pulsed power system. However, for slow or DC charged pulsed power systems this can be particularly challenging as the DC hold off of the PCSS dramatically declines. This paper presents results seeking to address HV switch performance requirements over large operating ranges by triggering using a pulsed charged PCSS based triggering system. Switch operating conditions as low as 45% of self break were achieved. A DC charged PCSS triggering system is also introduced and demonstrated over a 45 kV - 70 kV operating range. DC charged PCSS allow the triggering system to be directly charged from slow or DC charged pulsed power systems GaAs PCSS and neutron irradiated GaAs PCSS were used to investigate the DC charged operation.
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O22-4: GaAs PCSS for DC Charged Pulsed Power Applications
F. J. Zutavern1, S. F. Glover1, M. E. Swalby1, A. Mar1, G. Loubriel1, L. D. Roose1, F. E. White2
1Sandia National Laboratories, Albuquerque, NM, United States
2Ktech Corporation, Albuquerque, NM, United States
As the demand for pulsed power systems shifts to greater flexibility and the search for increased energy density continues to move highly interactive components closer together, development of technologies that result in less complex and more robust system designs is critical. A key system component that impacts these goals is the trigger generator (TG). Compact, fiber optically controlled, TGs that perform with sub-nanosecond jitter have been created based on photoconductive semiconductor switches (PCSS). However, to further simplify the use of PCSS in key system components the ability to move from pulsed charged designs to DC charged designs is critical. This paper reports results from studies on DC charged GaAs PCSS with 0.25 cm to 1.0 cm gaps that extends previously reported results on smaller devices at 3 kV to a new regime of 100 kV. High voltage GaAs photoconductive semiconductor switches (PCSS) are typically pulsed charged for less than 100 s so that they can hold-off 60-100 kV/cm without self-triggering into high-gain (lock-on) switching or initiating surface flashover. To hold-off high fields for longer periods and extend GaAs PCSS to DC applications, we have utilized neutron irradiated GaAs (n-GaAs). Neutron irradiation in GaAs increases the defect density, shortens the carrier recombination time, and (for devices with large insulating regions) reduces the device dark current, which improves DC hold-off strength. The PCSS in this research were created using rapid thermal annealing (RTA) to produce the best adhesion and lowest contact resistance. However, this can reduce the defect density near the contacts by annealing some of the n-induced defects. Hence, a range of RTA temperatures and neutron doses were studied to understand the tradeoff space for contact adhesion versus DC hold-off. This paper presents results from I-V characterization, DC hold-off, and switching tests on GaAs and n-GaAs based PCSS. Nonirradiated and irradiated PCSS devices were demonstrated to hold off fields of 45 kV/cm and 70 kV/cm respectively. Irradiation doses over a range of 3e13-1e15 (1 MeV Silicon equiv.) were explored in search for optimal performance. Additionally the impact of fabrication processes
on the benefits of irradiation is explored and the observation of unusual low frequency oscillations during GaAs I-V testing is discussed.
373
O22-5: Optically Isolated Circuit for Failure Detection of a Switch in a HV
Series Connected Stack V. Senaj, N. Voumard, M. J. Barnes,
L. Ducimetiere TE/ABT/FPS, CERN, Geneva, Switzerland
A stack of series connected high-power semiconductor switches is widely used in High Voltage (HV) and high current pulse generators for accelerator kicker magnets: this is due to advantages such as simpler control, longer life-time, lower rate of erratic pulses and no pre-heating requirements, compared to traditional gas switches. For reliability reasons, redundant semiconductors are included in the stack to preserve the HV stack functionality in the case of an individual semiconductor failure. In such a case the applied voltage is divided among residual functional semiconductors. Nevertheless, it is important to detect the failure of an individual semiconductor as soon as possible and to replace the faulty semiconductor. In the case of a ground referenced stack of semiconductors, it is feasible to measure the voltage on the switch closest to ground and therefore detect whether one of the series switches is faulty: however this is problematic when there are many series semiconductors or when the semiconductors exhibit different leakage current versus voltage or temperature characteristics or if they are not all at the same temperature. In addition, in the case of a floating stack of semiconductors, it is necessary to accurately measure differential voltage via galvanically isolated means. On our installation a detection system was required which could easily be retrofitted to existing switches with little modification of the system. A very simple and low cost solution was developed which is connected in parallel with each semiconductor. The proposed solution is based on extremely low power consumption Voltage Controlled Oscillator (VCO) with an optical coupling to detection logic; the VCO derives its power from the semiconductor off-state voltage. The VCO utilizes negative differential resistance of a reverse connected NPN planar-epitaxial transistor. Each semiconductor has its own VCO: failure or increase of switch leakage current leads to switch voltage reduction which will be rapidly detected by a lower VCO frequency compared to other switches in series. The VCO has a wide useful dynamic range: it operates from 300 nA supply current and is reasonably linear over 3 decades of applied voltage.
O22-6: A Miniature High-Power POS Driven by a 300 kV Tesla Charged PFL
Generator B. M. Novac, K. Rajesh, I. R. Smith,
C. Greenwood Electronic and Electrical Engineering,
Loughborough University, Loughborough, Leicestershire, United Kingdom
A pulsed power generator based on a high-voltage Tesla transformer charging a 3.8 ohm/53 ns water-filled pulse forming line (PFL) to 300 kV has been developed at Loughborough University as a training tool for pulsed-power students. The generator uses all forms of insulation specific to pulsed power technology – liquid (oil and water), gas (SF6) and vacuum, a series of fast voltage and current sensors, and is able to produce multi-GW pulses on a simple x-ray diode load. Recently, a miniature (cm-size) plasma opening switch (POS) using protons (H+ ions) has been coupled to the output of the 300 kV generator, with the overall system constituting the first phase of a programme aimed at the development of a novel repetitive, table-top generator capable of producing 15 GW pulses for high power microwave loads. Experimental results demonstrating the performance of the POS in reducing the 50 ns rise time of the input current to 5 ns in the x-ray load (ie by a factor of 10) will be presented, together with constructional details and diagnostic techniques. Future plans will be outlined.
374
O22-7: Reverse Matched Pulse Circuits with Minimum Loss
J. E. Barth Barth Electronics, Inc., Boulder City, NV, United
States
Pulse generation by discharging a charged transmission line or charged capacitors are well known, however such circuits are not reverse matched. Without reverse matching, pulses reflected by a poorly matched or unmatched load will be re-reflected by the unmatched generator back to the load which can cause undesirable effects at the load. Some circuits require that only a single well defined pulse be delivered to a load regardless of its impedance. One solution is to use an attenuator between the pulse source and the load to absorb reflections from an unmatched load. However this also absorbs part of the pulse. Only high values of attenuation will absorb the re-reflected pulse to minimal disturbance effects. High Voltage or Fast pulses are so difficult to generate that high values of attenuation to absorb most reflections waste much of the generated pulse. In Bode’s 1945 book “Network Analysis and Feedback Design” he described a constant resistance circuit to absorb all the energy reflected from a reactive load by adding a compliment load to the reactive load. This circuit was repeated in Metzger et. al. 1969 book “Transmission lines With Pulse Excitation” on pages 49-50. Reversing the direction of this basic principle can be used in a pulse generator to absorb reflections back to into it. This is accomplished by using two resistors equal to the impedance of the source circuit. They absorb part of the generated energy and all the reflected energy. The resistor absorbing all the reflected energy is connected to a parallel element which is the electrical complement to the source element. To absorb reflected rectangular pulses, we use two equal length transmission lines of equal impedance. The absorbing transmission line has a short circuit at its end to be the compliment to the open circuit transmission line used to produce the pulse. Discharging a capacitor through a 50 ohm resistor into an unmatched load uses its compliment value inductor in series with another 50 ohm resistor. These reverse match pulse circuits can be created for a charged transmission line or capacitor. Other more complex circuits can reverse matched with more complex complimentary elements. The basic compliment value required for reactive circuits are. This method provides a reverse matched pulse generator for loads which can range anywhere
from zero ohms to infinity ohms. Dynamic impedance loads which vary from low to high impedance during the pulse will also be absorbed. When a load abruptly crowbars for example, the amount of energy re-reflected back to the load can cause unacceptable errors in the measurement. Such re-reflections not only distort the waveform and make accurate measurements difficult; but also add unknown amounts of extra energy to the load. Such errors are difficult to recognize because complex impedance load are unknown until they are tested and are not always predictable. Absorbing energy in the pulse source can be a significant improvement in pulse power instrumentation because it absorbs the reflections from any type of load.
375
O22-8: Peculiar Photoconductivity in Nonlinear GaAs Photoconductive
Semiconductor Switch J. Yuan1, X. Wang1, W. Jiang1, H. Liu2, J. Liu2,
W. Xie2, H. Li2 1Department of Electrical Engineering, Tsinghua
University, Beijing, China 2Institute of Fluid Physics, China Academy of
Engineering Physics, Sichuan, China
Photoconductive semiconductor switches (PCSSs) are considered as promising devices for high-power applications. Since picosecond optoelectronic switching in silicon was published in 1975, especially from 1977, in which Si was replaced by GaAs, PCSSs have been significantly used in pulsed power technology, such as high-power ultra wideband microwave source and compact pulsed power generator. Since GaAs is a direct bandgap semiconductor, PCSSs fabricated from GaAs can operate in
linear and nonlinear mode. In the nonlinear mode, there is a special effect termed lock-on, which means that after the trigger laser pulse has ended, the voltage across the PCSS drops to a constant value and stays on, instead of dropping to zero. This work reports the peculiar photoconductivity in nonlinear GaAs photoconductive semiconductor switch. The PCSS with a gap of 18 mm was fabricated from semi-insulating GaAs and triggered by 1064 nm laser pulse. As the bias voltage increased, the FWHM of photocurrents also increased, the PCSS transited from linear mode to nonlinear mode. The switch behaved nonlinear at a bias voltage of 10 kV, with the obvious lock-on in photocurrent waveform. However, with a bias voltage above 10kV, the lock-on current increased instead of staying on a constant value, and as the bias voltage increased further, the slope of photocurrent also increased. The experimental results with different optical energy will be presented, and the mechanism of the peculiar photoconductivity will be discussed.
376
Author Index
A Abbaspour, A. -----------------------------------------231 Abdallah, C. T.-----------------------------------------174 Abdollahi, S. E. ----------------------------------344, 348 Abe, K----------------------------------------------277, 299 Abe, T----------------------------------------------------308 Åberg, D. ------------------------------------------197, 201 Abubakirov, E. -----------------------------------------200 Adamian, Y. E.-----------------------------------------182 Adhikary, B. --------------------------------------------114 Adler, R. J.----------------------------------181, 285, 330 Aganovic, E.--------------------------------------------230 Agapov, A. A. ------------------------------------------289 Agarwal, A. K.------------------------------156, 157, 235 Aggeler, D.----------------------------------------------228 Ahmed, W. A. ------------------------------------------230 Ahn, S. H. -----------------------------------------------295 Aici, Q. ---------------------------------------------------225 Akiyama, H. - 111, 180, 187, 245, 270, 277, 297, 299,
306, 307, 309, 311, 315, 333, 337, 338, 369 Akiyama, M. --------------------------------111, 297, 333 Akyuz, M. -----------------------------------------------347 Al Agry, A. ----------------------------------------------352 Alam, M. S. ---------------------------------------------346 Alberta, E. F. -------------------------------------------136 Aleksandrov, V. V.------------------------------------121 Alexander, J. A. ---------------------------------------152 Alexeenko, V. M. --------------------------------------216 Allen, A. J. ----------------------------------------------326 Allen, R. J. ----------------106, 130, 147, 148, 325, 351 Altgilbers, L. --136, 162, 163, 164, 165, 166, 282, 290 An, W.----------------------------------------------------211 Andersen, S. -------------------------------------------352 Anderson, D. E. ---------------------------------------359 Anderson, H. D. ---------------------------------------152 Anderson, R. A. ---------------------------------------354 Ando, N. -------------------------------------------------309 Andreev, A. D. -----------------------------------------197 Andrieu, J. ----------------------------------------------110 Angelova, M. A. ---------------------------------------141 Anisimov, A. G. ----------------------------------------254 Aoki, T. --------------------------------------------------311 Appelgren, P. ------------------------------------310, 347 Apruzese, J. P. ----------------------------------------148 Aragonez, R. -------------------------------------------336 Araki, J.--------------------------------------------------311 Arbuzov, A. A. -----------------------------------------113 Ariaans, T. H. P. --------------------------------------306 Arikawa, K. ---------------------------------------------309 Arnold, P. A.--------------------------------------------173 Arslanov, I. R.------------------------------209, 265, 368 Asmontas, S.-------------------------------198, 250, 301 Atchison, W. L. ----------------------121, 141, 144, 163 Atrazhev, V. M. ----------------------------------------189
Avdeev, S. M. ------------------------------------------367 Avila, T. G.----------------------------------------------238 Awe, A. J. -----------------------------------------------121 Azizkhan-Clifford, J. ----------------------------------320
B Babkin, A. B. -------------------------------------------143 Bailey, V. ------------------------------------------------213 Bailey, V. L.---------------------------------------------132 Baird, J.--------------------------------------164, 165, 166 Bajramovic, Z. -----------------------------------------230 Baksht, R.-----------------------------------------142, 348 Baksht,E. H. --------------------------------------------191 Banerjee, P. --------------------------------------------114 Banister, J.----------------------------------------125, 178 Barbee, K. ----------------------------------------------318 Barbosa, F. ---------------------------------------------173 Barinov, M. A.------------------------------------------243 Barnes, M. J. -------------------------------------------374 Barrett, D. -----------------------------------------------364 Barth, J. E.----------------------------------------353, 375 Bashkatov, Y. L.---------------------------------------254 Bates, J. F. ---------------------------------------------256 Bauer, B. S. --------------------------------------121, 141 Baum, C. ------------------------------125, 178, 195, 274 Baxter, E. -----------------------------------------------317 Bayne, S. B. --------------------------------------------169 Becker, E. C. -------------------------------------------202 Becker, K.-----------------------------------------------269 Beebe, S. -----------------------------------275, 278, 300 Begum, A.-----------------------------------------------319 Beilis, I. --------------------------------------------------142 Belkind, A. ----------------------------------------------269 Bennett, L. F.-------------------------------------152, 322 Benwell, A.----------------------------------------------317 Berghoefer, T. -----------------------------------------293 Berninger, M. J. ---------------------------------106, 340 Berry, C. L. ---------------------------------------------325 Beukers, T. ---------------------------------------262, 263 Bharadwaja, S. S. N.---------------------------------171 Bhasin, L. -----------------------------------------------215 Biela, J. --------------------------------------228, 360, 361 Blackmore, P. F. --------------------------------------275 Blanchard, J. P. ---------------------------------------248 Bland, S. ------------------------------------------------119 Blell, U. --------------------------------------------------220 Blickem, J. R. ------------------------------------------152 Bliss, D. E. ----------------------------------------221, 238 Bochkov, D. V.-----------------------------------154, 343 Bochkov, V. D.-----------------------------------154, 343 Boggs, S. A. --------------------------------------170, 260 Bogomaz, A. A.----------------------------------------355 Bokhan, P. A. ------------------------------------------343
377
Bokka, R.------------------------------------------------292 Bolshakov, M. A. --------------------------------------301 Bolyard, D. W. -----------------------------------------136 Boriskin, A. S.------------------------------------243, 289 Bortis, D. ------------------------------------360, 361, 363 Boussetta, N.-------------------------------------------313 Boyer, C. N. --------------------------------------------253 Brasile, J. P.--------------------------------------------110 Brommer, V.--------------------------------------------237 Brooks, A.-----------------------------------------318, 320 Brown, D. -----------------------------------------------257 Brown, D. J. --------------------------------------------329 Browning, N. D. ---------------------------------------366 Bruner, N. -----------------------------------------107, 213 Buchanan, K. ------------------------------------------352 Buchenauer, C. J. ------------------------------------174 Buchenauer, J. ----------------------------------117, 184 Budin, A. V.---------------------------------------------355 Bui, B.----------------------------------------------132, 212 Buldakov, M. A. ---------------------------------------301 Burachenko, A. G. ------------------------------------191 Burke, K. M. --------------------------------185, 302, 370 Burke, M. E. --------------------------------------------340 Burkhart, C.---------------159, 262, 263, 265, 359, 362 Burns, P. M. --------------------------------153, 214, 357 Burtsev, V. A. ------------------------------------------246 Buyko, A. M. --------------------------------------144, 240 Bychkova, E. A. ---------------------------------------243 Bykov, D. N. --------------------------------------------115 Bykov, N. M.--------------------------------------------115 Byrne, P. C. --------------------------------------------346
C Cadilhon, B. --------------------------------------110, 331 Calamy, H.----------------------------------112, 119, 131 Callanan, R. --------------------------------------------157 Camacho, J. F. ----------------------------------------329 Cambonie, F.-------------------------------------------119 Camp, J. T. ---------------------------------------195, 275 Campbell, G. H. ---------------------------------------366 Campbell, J. D. ----------------------------------------185 Cann, D. P. ---------------------------------------------171 Capell, C. -----------------------------------------------157 Caron, M. -----------------------------------------210, 211 Carp, C. -------------------------------------------261, 262 Carsimamovic, A. -------------------------------------230 Carsimamovic, S. -------------------------------------230 Cassany, B. --------------------------------------------331 Cassel, R. L. -------------------------------------------263 Ceccato, P. ---------------------------------------------272 Celestin, G. ---------------------------------------------223 Cerchar, E. ---------------------------------------318, 320 Chaikovsky, S.-----------------------------------------355 Chakravarthy, D. P. ----------------------------------332 Chen, H.-------------------------------------------------222 Chen, L. -------------------------------------------219, 322 Chen, M. T. ---------------------------------------------278 Chen, W. ------------------------------------------------312 Chen, X. -------------------------------------------------278 Chen, Y. J.----------------------------------------------151 Cheng, C.H. --------------------------------------------185
Cheng, S. H. -------------------------------------201, 310 Cherdyntseva, N. V.----------------------------------301 Cherenshchykov, S.----------------------------------207 Chernyshev, V. V. ------------------------------------356 Childers, F. K.------------------------------------------285 Childress, B.--------------------------------------------364 Chistyakov, V. P.--------------------------------------254 Chittenden, J. ------------------------------------------325 Cho, J. H. -----------------------------------------------349 Choi, D. W. ---------------------------------------------352 Choi, J. --------------------------------------------------309 Choi, O. R.----------------------------------------------333 Christensen, J. S. -------------------------------------342 Chung, S. S. M. ---------------------------185, 201, 310 Chupin, V. V. -------------------------------209, 265, 368 Churkin, D. S. ------------------------------------------343 Cich, M. J. ----------------------------------------------372 Ciprian, R. C.-------------------------------------------350 Clark, M. C.---------------------------------------------288 Clark, R. E. ---------------------------------------------323 Clough, S.-----------------------------------------107, 351 Coblentz, M---------------------------------------------364 Coffey, S. K.--------------------------------------138, 329 Coffo, M. I. R. ------------------------------------------253 Colgate, S. A. ------------------------------------------163 Combes, P. ---------------------------------------112, 119 Commisso, R. J.---------------131, 147, 148, 325, 351 Cong, P. T. ---------------------------------------------133 Cook, E. G. ---------------------------------------------366 Cooper, R. A. ------------------------------------------256 Cooperstein, G. ---------------104, 106, 147, 148, 325 Corcoran, P. A. ----------------------------------------132 Cordova, S.---------------104, 105, 107, 129, 132, 340 Costerton, J. W. ---------------------------------------278 Crain, D.-------------------------------------------------104 Critchley, A. --------------------------------------------107 Crotch, I. ------------------------------------------------107 Cuneo, M. E. -------------------------------231, 282, 323 Curry, R. D.---------------140, 152, 169, 270, 271, 294 Cvetic, J. M. --------------------------------------------186
D Dale, G. E. ----------------------------------160, 336, 358 Dalmas, D.----------------------------------------------321 Danchenko, E. G.-------------------------------------243 Daout, B. ------------------------------------------------339 Darling, J. D. C. ---------------------------------------126 DaSilva, T. ----------------------------------------------125 David, H. D. --------------------------------------------326 Davis, B.-------------------------------------------------290 Davis, C. ------------------------------------------------290 Davis, J. P. ---------------------------------255, 322, 324 Day, J. ---------------------------------------------------258 De Ferron, A.-------------------------------------110, 312 Deb, P.---------------------------------------------------114 Degnan, J. H. ------------------------------------------138 DeHope, W. J. -----------------------------------------366 Demidov, V. A.-----------------------------------243, 289 Deng, J. -------------------------------------------------322 Devarapalli, N. R. -------------------------------------232
378
Dickens, J. --- 128, 136, 137, 151, 160, 162, 228, 271, 281, 290
Diehl, J.--------------------------------------------------252 Dirk, S. M.-----------------------------------------------168 DiSanto, T. M. -----------------------------------302, 370 Dobrynin, D. --------------------------------------------318 Dominik, B. ---------------------------------------------228 Domonkos, M. -----------------------------------------260 Domonkos, M. T.--------------------------------------257 Dong, Z. W.---------------------------------------------137 Douglas, J. W. -----------------------------------------132 Dowden, J.----------------------------------------287, 370 Droemer, D. W.----------------------------------104, 108 Drozdov, A. A. -----------------------------------------232 Drumheller, W.-----------------------------------------364 Du, Y. ----------------------------------------------------123 Ducimetiere, L. ----------------------------------------374 Duday, P. V.--------------------------------------------239 Dyagilev, V. M. ----------------------------------------343 Dyublov, A. A.------------------------------------------182
E Efanov, --------------------------------------------------182 Efanov, M. V.-------------------------------------113, 289 Efanov, V. M.-------------------------113, 127, 182, 289 Efimov, I. P. --------------------------------------------233 Egorychev, B. T. --------------------------------------356 Eing, C. --------------------------------------------------315 El Bahy, M. ---------------------------------------------191 Elfsberg, M.---------------------------------------117, 347 Elsayed, M. ---------------------------------------------162 Elsayed, M. ---------------------------------------------163 El-Sharkh, M. Y.---------------------------------------346 El-Zein, A.-----------------------------------------------191 Emerson, M. R.----------------------------------------171 Engel, T. G.---------------------------------------------253 Engelson, V. -------------------------------------------301 Enikeev, R. S.------------------------------112, 177, 232 Ennis, J. B. ---------------------------------------------256 Ermolovich, V. F.--------------------------------------243 Erofeev, M. V.------------------------------------------367 Etchessahar, B. ---------------------------------------211 Evans,S. J. ---------------------------------------------187
F Favre, M. ------------------------------------------------241 Featherstone,E. ---------------------------------------325 Fedorov, S. V. -----------------------------------------143 Fedulov, V. V.------------------------------------------121 Fedunin, A. ---------------------------------------------355 Feduschak, V. -----------------------------------------355 Felsteiner, J. -------------------------------------149, 215 Feng, X. P.----------------------------------------------317 Fengju, S. -----------------------------------------------225 Ferriera, T. J.-------------------------------------192, 342 Fielding, A. M. -----------------------------------------153 Filippov, A. V. ------------------------------------243, 289 Fisher, R.------------------------------------------------325 Fleming, T. P.------------------------------------------196
Flerov, A. N. --------------------------------------------227 Flickinger, B. -------------------------------------------293 Focia, R. J. ---------------------------------------------334 Foster, J. ------------------------------------------127, 194 Fowler, W. E.-------------------------------------------327 Frank, K. ------------------------------------220, 271, 333 Freeman, B. --------------------------------------------136 French, D. M. ------------------------203, 231, 276, 282 Frey, W. -------------------------------------------279, 293 Fridman, A. ---------------------------------------318, 320 Fridman, B. E. -----------------------------112, 177, 232 Fridman, G.---------------------------------------------318 Friedman, G. -------------------------------------318, 320 Friedman, M. -------------------------------------153, 214 Friedrichs, P. -------------------------------------------157 Frolov, I. N. ---------------------------------------------121 Frolov, O. -----------------------------------------------245 Frolov, S. V. --------------------------------------------216 Frost, C. A. ---------------------------------------------334 Fuelling, S.----------------------------------------------121 Fujiwara, T. ---------------------------------296, 308, 314 Fukawa, F.----------------------------------------------307 Fuks, M. -------------------------------------------------117 Fuks, M. I.-----------------------------------116, 197, 205 Fukuhara, H --------------------------------------------187 Furman, E.----------------------------------------------259
G Gafri, O. -------------------------------------------------295 Gahl, J. M. ----------------------------------------------202 Gallant, J. -----------------------------------------------253 Galleani, S. ---------------------------------------------174 Gao, Y. --------------------------------------------------303 Garagaty, S. N. ----------------------------------209, 368 Garanin, S. F.------------------------121, 141, 144, 244 Garipov, R. M. -----------------------------------------289 Garner, S.-----------------------------------------------352 Gaudet, J.-----------------------------------------------255 Gaudreau, M. P. J. -----------------------------------350 Gekenidis, S.-------------------------------------------236 Georges, A.---------------------------------------112, 131 Gershman, S. ------------------------------------------269 Gibbons, B. J.------------------------------------------171 Giesselmann, M. --------------------------252, 285, 286 Gignac, R. E.-------------------------------------105, 340 Gilbrech, J. A.------------------------------------285, 330 Gilgenbach, R.-----------------------------------------213 Gilgenbach, R. G.-------------------------------------129 Gilgenbach, R. M.-------------203, 231, 247, 276, 282 Gilmore, M. ---------------------------------149, 220, 232 Gintsburg, V. A. ---------------------------------------205 Giorgi, D. ------------------------------------------------223 Giri, D. ---------------------------------------------125, 178 Giterman, B. P. ----------------------------------------243 Giuliani, J. L. -------------------------------153, 214, 357 Given, M. J.---------------------------------189, 190, 292 Gleizer, J. -----------------------------------------------149 Gleizer, J. Z.--------------------------------------212, 215 Glidden, S. C. ------------------------------------229, 330 Glover, S. F.--------------------------154, 255, 372, 373 Gnedin, I. N.--------------------------------------------154
379
Go, T. ----------------------------------------------------296 Goerz, D. A. --------------------188, 192, 268, 342, 354 Goforth, J. H.-------------------------------------------163 Golbert, J. E. -------------------------------------------256 Golosov, S. N. -----------------------------------------289 Gomez, M. R. ------------------------------231, 247, 282 Good, D. E. ---------------------------------------105, 340 Gorbachev, Y. N.--------------------------------144, 240 Gorodetsky, V.-----------------------------------217, 364 Gorur, A. ------------------------------------------------278 Goyer, R. J.---------------------------------------------131 Grabovski, E. V. ---------------------------------------121 Grabowski, T. C. --------------------------------------329 Greenwood, C. ----------------------------291, 335, 374 Gregg, C. W. -------------------------------------257, 329 Grekhov, I. V. ------------------------------------------328 Gribov, A. N. -------------------------------------------121 Gric, T.---------------------------------------------198, 250 Griego, J. R.--------------------------------------163, 175 Griffin, A. ------------------------------------------------223 Gritsouk, A. N. -----------------------------------------121 Gruner, F. R. -------------------------------------------152 Gryaznov, O. V. ---------------------------------------343 Guaitella, O. --------------------------------------------272 Gubanov, V. V. ----------------------------------------327 Gundersen, A. -----------------------------------------222 Gundersen, M. A. -------------------------278, 286, 365 Gunin, A. V. --------------------------------------115, 327 Guo, R. --------------------------------------------------219 Gurovich, V. T.-----------------------------------212, 215 Gusbeth, C. A. -----------------------------------------279 Guzik, J. A. ---------------------------------------------163
H Hackenberger, W. ------------------------136, 258, 260 Hadas, Y. -----------------------------------------118, 212 Hahn, K. -------------------------------------107, 212, 213 Haines, T. -----------------------------------------104, 106 Hall, C. A. -----------------------------------------------255 Handa, T. -----------------------------------------------305 Hansen, M. D. -----------------------------------------105 Hara, M. -------------------------------------------------187 Harden, M. J.-------------------------------------------152 Harper-Slaboszewicz, V. J.-------------------131, 146 Hatfield, C. W. -----------------------------194, 287, 345 Hatfield, L. L. -------------------------------------------340 Hawkey, T.----------------------------------------------350 Hazelton, D. --------------------------------------------145 He, J.-----------------------------------------------------219 Heathcote, A. ------------------------------------------107 Heesch, E. J. M. V.-----------------------------176, 306 Hegeler, F.----------------------------------153, 214, 357 Heidger, S.----------------------------------152, 257, 260 Hemmert, D. J. ----------------------------------------136 Henderson, D. J. --------------------------------105, 340 Hendricks, K. J. ---------------------------------------197 Henriquez, S. L. ---------------------------------------169 Heo, H. --------------------------------------219, 333, 352 Hernandez-Llambes, J. C.--------------------------145 Herrera, D. H. ------------------------------------------163 Hettler, C. -----------------------------------------160, 228
Hickman, R. J. -----------------------------------------255 Hinshelwood, D.-- 104, 106, 130, 147, 148, 322, 325,
351 Hirakawa, M. -------------------------------------------277 Ho, J.-----------------------------------------------------256 Hodge, K. C. -------------------------------------154, 255 Holt, S. L. -----------------------------------------------282 Holt, T. A. -----------------------------------195, 288, 329 Holtkamp, D. B. ---------------------------------------163 Hope, M. ------------------------------------------------285 Hosseini, S. H. R. -------------------------270, 315, 369 Hotta, E. -------------------------------------------------347 Houck, T. L. --------------------------------188, 192, 268 Hourdin, L. ----------------------------------------------210 Hsu, S. C. -----------------------------------------------149 Huang, J.------------------------------------------------257 Huang, Y. -----------------------------------------------280 Huhman, B. M.-----------------------------------106, 254 Hurtig, T. ------------------------------------203, 310, 347 Hutsel, B. T. --------------------------------------------316 Huynh, P. -----------------------------------------------372 Hwang, H.-----------------------------------------------249
I Ibbotson, R. A.-----------------------------------------187 Idzorek, G. ----------------------------------------------163 Ihara, S. -------------------------------------------------316 Iizasa, S. ------------------------------------------------311 Ilic, G. ----------------------------------------------------233 Inokuchi, M. --------------------------------------------111 Inoue, S.-------------------------------------------------311 Inuzuka, R. ---------------------------------------------316 IRomanchenko, I. V. ---------------------------------115 Iskander, S. M. ----------------------------------------179 Itoh, H. ---------------------------------------------------307 Ivanov, A. Y.--------------------------------209, 265, 368 Ivanov, V. A.--------------------------------------------239 Ivanov, V. V.--------------------------------------------120 Ivanova, G. G. -----------------------------------------144 Ivanovskiy, A. V. --------------------144, 239, 240, 356 Iwasaki, S. ----------------------------------------315, 369
J Jackson, D. P. -----------------------------------------232 Jackson, S. L.------------------------------147, 148, 325 Jacques, A. ---------------------------------------------312 James, C. -----------------------------------------160, 228 James, G. F. -------------------------------------------173 Jang, S. R.----------------------------------------295, 358 Jang, W.-------------------------------------------------219 Jankowski, N. R. --------------------------------------264 Jansen, K. ----------------------------------------------364 Jansson, M. E.-----------------------------------------201 Javedani, J. B. -----------------------------188, 192, 268 Jaynes, R. L. -------------------------------153, 214, 357 Jeftenic, B. I. -------------------------------------------186 Jiahui, Y. ------------------------------------------------225 Jian, J.Y. ------------------------------------------------185 Jiang, C.-------------------------------------222, 278, 365
380
Jiang, W. ------------------------------118, 181, 221, 376 Jin, Y. S.-------------------------------------------295, 349 Johnson, D. L. -----------------------------------129, 132 Johnson, W. --------------------------------------------222 Johnson,J. ----------------------------------------------321 Johnston, B. D. ----------------------------------------212 Johnston, M. D. ---------------------------------107, 108 Jolin, R.--------------------------------------------------364 Jones, A. ------------------------------------------------107 Jones, A. W. P. ----------------------------------------210 Jones, B. M. --------------------------------------------323 Jones, G. R. --------------------------------------------144 Joshi, S. -------------------------------------------------256 Jow, R.---------------------------------------------------256 Ju, H.-----------------------------------------------------249 June, M. S. ---------------------------------------------318 Junjia, H. ------------------------------------------------234 Jurosevic, M. -------------------------------------------233
K Kai, H.----------------------------------------------------277 Kalghatgi, S. -------------------------------------318, 320 Kalinin, N. V. -------------------------------------------246 Kang, D. K. ---------------------------------------315, 369 Karakas, E. ---------------------------------------------319 Kardo-Sysoev, A. F.----------------------------------227 Karhi, R. W. --------------------------------------------252 Karlsson, M. U. ----------------------------------197, 201 Katsis, D.------------------------------------------------169 Katsuki, S. ----------------245, 270, 277, 299, 309, 315 Kaul, A. --------------------------------------------------163 Kaul, A. M. ----------------------------------------------291 Kavitha, D. ----------------------------------------------369 Kawamoto, K. ------------------------------180, 270, 333 Kazakov, S. A. -----------------------------------243, 289 Kazakova, N. P. ---------------------------------------289 Keller, N. ------------------------------------------------256 Kelly, C. -------------------------------------------------320 Kemp, M.------------------------------------262, 263, 359 Kempkes, M. -------------------------------------------350 Kesar, A. S.---------------------------------------------227 Kharlov, A. V. ------------------------------------------224 Khramtsov, S.------------------------------------------218 Kim, A. A. -----------------------------------129, 216, 327 Kim, B. ---------------------------------------249, 296, 358 Kim, J. S.------------------------------------113, 349, 358 Kim, S. C. -----------------------------------------------333 Kim, S. H. -----------------------------------113, 333, 352 Kim, Y. B. -----------------------------------------------349 King, N. --------------------------------------------------104 King, W. E.----------------------------------------------366 Kinoshita, Y.--------------------------------------------297 Kirkici, H. ------------------------------------241, 292, 313 Kirkpatrick, R. C. --------------------------------------163 Kiselev, V. N.-------------------------------------------327 Kiyan, T.-------------------------------------------------187 Kladukhin, S. -------------------------------------------218 Kladukhin, V. -------------------------------------------218 Klimov, A. I.---------------------------------------115, 206 Knudson, M. D. ----------------------------------------324 Knyazeva, I. R. ----------------------------------------301
Ko, K. ----------------------------------------------249, 296 Kobayashi, T. ------------------------------------------305 Koch, B. -------------------------------------------------259 Kofujita, H. ----------------------------------------------314 Kolacek, K. ---------------------------------------------245 Kolar, J. W. ---------------------------228, 360, 361, 363 Kolb, J. F. -----------------------------------------278, 300 Kolganov, N. G. ---------------------------------------205 Kolikov, V. A.-------------------------------------188, 328 Kolokolov, D. Y. ---------------------------209, 265, 368 Komashko, A. V. --------------------------------------113 Kono, S. -------------------------------------------------315 Kononenko, A. V. -------------------------------------233 Konstantinov, A. U.-----------------------------------232 Konyushkov, A.----------------------------------------200 Korn, J. --------------------------------------------------290 Korotkov, S. V.-----------------------------------------328 Koschmann, E. ----------------------------------------285 Kostyrya, I. D.------------------------------------191, 246 Kouda, A. -----------------------------------------180, 333 Kouno, K. -----------------------------180, 270, 297, 333 Kovaleski, S. D. ---------------------160, 202, 316, 317 Kovrizhnykh, N. A.------------------------------112, 232 Kraev, A. I.----------------------------------------239, 356 Krasik, Y. E. --------------------------118, 149, 212, 215 Kribs, J. D. ----------------------------------------------318 Kriklenko, A. V. ----------------------------113, 127, 289 Krile, J. T. -----------------------------------128, 136, 137 Kristiansen, M.---- 128, 136, 137, 151, 162, 163, 282,
286, 290 Krivosheev, S. I.---------------------------------------182 Krompholz, H.------------------------------------127, 194 Kryukov, U. L.------------------------------------------232 Kudelkin, V. B. -----------------------------------------356 Kumkova, I. I. ------------------------------------298, 299 Kuramochi, Y-------------------------------------------303 Kuschev, S. A. -----------------------------------------304 Kutenkov, O. P. ---------------------------------------301 Kutenkov, V. O. ---------------------------------------115 Kuthi, A. -------------------------------------------286, 365 Kutumov, S. V.-----------------------------------------289 Kuwahata, A.-------------------------------------------245 Kuzmin, K. A. ------------------------------------------298 Kuznetsov, S. D. --------------------------------121, 244 Kuznetsov, V. E. --------------------------------------298 Kweller, T. ----------------------------------------------118 Kwon, J. W.---------------------------------------316, 317 Kwon, S.-------------------------------------------------258
L Labetskaya, N. ----------------------------------------355 Laborderie, C.------------------------------------------312 Ladov, S. V. --------------------------------------------143 LaGrange, T. B. ---------------------------------------366 Lahowe, D.A.-------------------------------------------268 Laity, G. -------------------------------------------------271 Lalande, M. ---------------------------------------------110 Lam, J. B. -----------------------------------------------172 Lan, J. W. -----------------------------------------185, 310 Lanagan, M. T. ----------------------------------171, 259 Langston, W.L. ----------------------------------------324
381
Lanoiselle, J. L.----------------------------------------313 Lapin, I. N. ----------------------------------209, 265, 368 Lara, M. B. ----------------------------288, 329, 345, 370 Laroussi, M. --------------------------------------------319 Larsen, R.-----------------------------------------262, 265 Larsson, A. ---------------------------117, 203, 310, 347 Lashmanov, Y. N.-------------------------------243, 289 Lassalle, F. ---------------------------------112, 119, 131 Lassus, J. -----------------------------------------------312 Lau, Y. Y. -----------------203, 213, 231, 247, 276, 282 Laukhin, Y. N.------------------------------------------121 Lavrukhin, M. A. ---------------------------------------343 Le Galloudec, B. --------------------------------------350 Leask, P.J.----------------------------------------------187 LeChien, K. R. -----------------------------129, 221, 327 Leckbee, J. J. ------------------107, 129, 132, 212, 213 Lee, B. H. -----------------------------------------------113 Lee, B. J. ------------------------------------------------220 Lee, P. S. -----------------------------------------------172 Lehr, F. M. ----------------------------------------------138 Lehr, J. M. ----------------------------------154, 190, 255 Leitner, M. A.-------------------------------------------176 Lemke, R. W. ------------------------------------------324 Letchford, A.--------------------------------------------350 Levine, J. S. --------------------------------------125, 178 Li, H.------------------------------------149, 181, 221, 376 Li, J. ------------------------------------------------------347 Li, M. T.--------------------------------------------341, 343 Li, S.------------------------------------241, 280, 292, 313 Li, W. -----------------------------------------------------257 Li, Z. ------------------------------------------------------270 Lin, H. Y. ------------------------------------185, 201, 310 Lin, M. F. ------------------------------------------------172 Lindemuth, I. R. ---------------------------------121, 141 Lipham, M.----------------------------------------------313 Lips, J. A. -----------------------------------------------339 Litvyakov, N. V.----------------------------------------301 Litz, M. S. -----------------------------------------------169 Liu, C. Y. ------------------------------------------------357 Liu, D. X. ------------------------------------------------225 Liu, H. ----------------------------------------221, 235, 376 Liu, J.-----------------------------------------------221, 376 Liu, K. ----------------------------------------------181, 335 Liu, W. ---------------------------------------------------149 Liu, Z. ----------------------------------------------176, 306 Livshiz, Y. Y. -------------------------------------------295 Lobanov, K. M. ----------------------------------------112 Lockner, T.----------------------------------------------254 Lodes, A. ------------------------------------------------294 Lomaev, M. I. ------------------------------------191, 367 Long, F. W. ---------------------------------------------129 Lopes, D. T. --------------------------------------------202 Lopez, M. R.--------------------------------------------231 Loree, D. L. ---------------------------------------------124 Loree, E. ------------------------------------------------260 Lors, C. --------------------------------------------------364 Losev, S. Y. --------------------------------------------355 Loubriel, G. ---------------------------------------372, 373 Loyen, A. ------------------------------------112, 119, 131 Lucero, D. J.--------------------------------------------255 Ludeking, L. D. ----------------------------------------207 Luginsland, J. W.--------------------------------------203
Lukyanov, S. A. ---------------------------------------304 Lutz, S. S.-----------------------------104, 105, 106, 340 Lynn, A. G.----------------------------------------149, 232 Lynn, C. F. ----------------------------------------------137 Lyons, K. M. --------------------------------------------318 Lyubutin, S. K. -----------------------------------------161
M Ma, J. ----------------------------------------------------172 MacDougall, F. W.------------------------------------256 MacGregor, S. J. --------------------------189, 190, 292 Macken, K.----------------------------------262, 263, 265 Madrid, E. A. -------------------------------------------323 Maeda, S. -----------------------------------------------311 Magassarian, A. ---------------------------------------357 Makhin, V. ----------------------------------------------141 Malkov, A. A. -------------------------------------------232 Maltsev, A. N. ------------------------------209, 265, 368 Manju, M. -----------------------------------------------369 Manzanares, C. ---------------------------------------364 Mar, A. ---------------------------------------------372, 373 Maric, R.-------------------------------------------------233 Marinin, N. N. ------------------------------------------143 Marjanovic, S.D.---------------------------------------186 Markevtsev, I. M.--------------------------------------243 Martavicius, R.-----------------------------198, 250, 301 Martin, P. N. --------------------------------------------108 Martinez, D. --------------------------------------------120 Matallah, M. --------------------------------------------312 Matia, D.-------------------------------------------------286 Matinez, B. M. -----------------------------------------329 Matrosov, A. D. ----------------------------------------143 Matsumoto, T. -----------------------------------------306 Matsuo, K. ----------------------------------------------298 Matzen, M. K. ------------------------------------------129 Maurel, O.-----------------------------------------------312 Maury, P.------------------------------------------------112 Mayes, J. R. --------------194, 287, 288, 329, 345, 370 Mayes, M. G.-------------------------------194, 329, 370 Mazarakis, M. G. --------------------129, 231, 282, 327 McCluskey, F. P. --------------------------------------264 McDaniel, B.--------------------------------------------350 McDaniel, D. H. ---------------------------------------255 McHale, G. B. ------------------------------------173, 354 McKee, R. G.-------------------------------------------129 McKenney, J. L. ---------------------------------------129 McKinney, J. L. ----------------------------------------282 McNab, I. R. --------------------------------------------251 McQuage, L. M. ---------------------------------------128 Medovshikov, S. F. -----------------------------------121 Mehlhorn, T. A. ----------------------------------------282 Melcher, J. ----------------------------------------------157 Menikoff, R.T. ------------------------------------------163 Merensky, L. M. ---------------------------------------227 Merrill, F. E. --------------------------------------------175 Mesyats, G. A.-----------------------------------193, 294 Migliaccio, M. ------------------------------------------195 Mikkelson, K. A. ---------------------------------131, 146 Miller, A. T. ---------------------------------------------325 Miller, C. L. ---------------------------------104, 105, 323 Minamitani, Y.------------------------------303, 305, 308
382
Mirzaei, M. ----------------------------------------344, 348 Mitra, S. -------------------------------------------------332 Mitrofanov, K. N. --------------------------------------121 Mitsutake, K. -------------------------------------------277 Mitton, C. V. --------------------------------------105, 340 Miyaji, K. ------------------------------------------------187 Mller, G. -------------------------------------------------279 Modin, p. ------------------------------------------------331 Moeller, C. ----------------------------------------------347 Mohamed Ali, M. K. ----------------------------------273 Moiseenko, A. N.--------------------------------243, 289 Mokhov, V. N.------------------------------------------144 Molina, I. ------------------------------104, 105, 107, 340 Möller, C.---------------------------------28, 52, 117, 203 Mora, C. -------------------------------------------125, 178 Mora, N. -------------------------------------------------339 Morell, A. ------------------------------------------------112 Morotom, K. --------------------------------------------277 Morozova, I. V. ----------------------------------------144 Morss-Clyne, A. ---------------------------------------320 Morton, D.-----------------------------------------125, 178 Mosher, D. ----------------------------104, 106, 147, 148 Mostrom, C. B.-----------------------------------------323 Motalleb, M. --------------------------------------------231 Motta, C. C.---------------------------------------202, 208 Mueller, G. ----------------------------------------211, 315 Mukaigawa, S. -----------------------------296, 308, 314 Murphy, D. P. ------------------------------131, 147, 148 Myers, M. C.--------------------------------------153, 214
N Naff, T.---------------------------------------------125, 178 Nagane, K.----------------------------------------------314 Nagano, K.----------------------------------------------245 Nagesh, K. V. ------------------------------------------332 Nakamitsu, S. ------------------------------------315, 369 Nakonechny, G. V. -----------------------------------304 Nalajala, V. ---------------------------------------------350 Nam, S. H. ----------------------------------219, 333, 352 Namihira, T. --------------------------306, 307, 309, 311 Narimatsu, M. ------------------------------------------314 Naruo, C.------------------------------------------------256 Navapanich, T. ----------------------------------------223 Neff, S.---------------------------------------------------120 Nelson, D.-----------------------------------104, 105, 340 Neri, J. M. -----------------------------------------253, 254 Neuber, A. --- 127, 128, 136, 137, 162, 163, 194, 271,
281, 286, 290 Nguyen, M. ---------------------------262, 263, 265, 359 Niasse, N.-----------------------------------------------119 Nickelson, L. -------------------------------198, 250, 301 Nielsen, K. ----------------------------------------------321 Nieter, C. ------------------------------------------------214 Nikonov, A. V.------------------------------------297, 299 Nomura, N. ---------------------------------------277, 299 Norgard, P. ---------------------------------------------270 Nose, T. -------------------------------------------------305 Novac, B. M. -------------------------------291, 335, 374 Nuic, S. --------------------------------------------------230 Nunnally, C. --------------------------------287, 288, 345 Nunnally, W. C.----------------------------------194, 370
Nyholm, S. E. ------------------------------117, 203, 347
O O’Brien, H. K. ------------------156, 157, 158, 227, 235 O'Connor, K. A.----------------------------------140, 169 Ogihara, H. ---------------------------------------------171 Ogunniyi, A. --------------------------156, 158, 227, 235 Ohtsu, M.------------------------------------------------311 Olabisi, S. -----------------------------------------------185 Oleinik, G. M. ------------------------------------------121 Oleynik, G.----------------------------------------------122 Oliver, B. V.-- 104, 105, 106, 107, 108, 129, 132, 212,
213, 282 Olsen, J.-------------------------------------262, 265, 362 Olsson, F. -----------------------------------------197, 201 Onyenucheya, B. -------------------------------302, 370 Oona, H.-------------------------------------------------163 Oreshkin, V. --------------------------------------142, 355 Orlov, A. P. ---------------------------------------243, 244 Ormond, E. C. -----------------------------------------104 Ormond, E. C. -----------------------------------------105 Ormond, E. C. -----------------------------------------340 Oro, D. M.-----------------------------------------------175 Ortiz, G. I. -----------------------------------------------363 Osmokrovic, P. ----------------------------186, 230, 233 Ottinger, P. F.------------130, 146, 147, 148, 325, 326 Ouyang, W. M.-----------------------------------217, 218 Ovchinnikov, R. V.------------------------297, 298, 304
P P. D. P ---------------------------------------------------332 Pak, S. V. -----------------------------------------------239 Pal, D. K. ------------------------------------------------234 Palisek, L.-----------------------------------------------336 Pan, R. Z. -----------------------------------183, 217, 218 Pan, Y.---------------------------------------------------219 Panov, P. V. --------------------------------------------154 Park, S. S. ----------------------------------219, 333, 352 Parker, J. V. --------------------------------138, 251, 329 Parson, J. -----------------------------------------------281 Pavlinko, J. ---------------------------------------125, 178 Pavliy, V. V. --------------------------------------------240 Pavlov, A. V. -------------------------------------297, 299 Pavlov, S. E. -------------------------------------------289 Pecastaing, L. -----------------------------------110, 313 Pemen, A. J. M. ---------------------------------176, 306 Pena, G. E. ---------------------------------------154, 255 Peña, N. -------------------------------------------------339 Pendleton, D. L. ---------------------------------------173 Pendleton, S. J. ---------------------------------------286 Peng, L. -------------------------------------------------225 Perkins, M. P. ------------------------------------------188 Petersen, D. E. ----------------------------------------173 Petrukhin, A. A.----------------------------144, 239, 240 Petzenhauser, I.J. ------------------------------------220 Pfeffer, H. -----------------------------------------------326 Phipps, D. G.-------------------------------------325, 351 Pichon, S. J.--------------------------------------------210 Pignolet, P. ---------------------------------------------110
383
Pihl, C. ---------------------------------------------------154 Pijaudier, G. --------------------------------------------312 Pikulin, I. V.---------------------------------------------243 Pinchuk, M. E. -----------------------------------188, 355 Plechaty, C. --------------------------------------------120 Plyashkevich, L. N. -----------------------------------289 Podolsky, E. --------------------------------------------318 Pointon, T. D. ------------------------------------323, 324 Pokrovsky, D. S. --------------------------------------243 Pokrovsky, V. S. --------------------------------------243 Pokryvailo, A. ------------------------261, 262, 348, 359 Polyakov, M. A.----------------------------------------355 Popov, S. D.--------------------------------297, 299, 304 Porter, J. L. ---------------------------------------------129 Portillo, S. -----------------------104, 106, 107, 108, 212 Poulsen, P. ---------------------------------------------329 Prabahar, T. --------------------------------------------114 Prasad, S.-----------------------------------------------117 Presura, R. ---------------------------------------------120 Price, D. T.----------------------------------------------330 Prichard, B. ---------------------------------------------321 Provencio, P.P. ----------------------------------------248 Prukner, V.----------------------------------------------245 Puissant, J. G. -----------------------------------------255 Pyke, B. J. ----------------------------------------------366
Q Qin, S. ---------------------------------------------------260 Qiu, A. C.------------------------------------------------133 Qiu, G. ---------------------------------------------------317 Qiu, J. ----------------------------------------------------335
R Rachidi, F. ----------------------------------------------339 Rahaman, H. -------------------------------------219, 333 Rahman, A.---------------------------------------------346 Rajesh, K.-----------------------------------------------374 Randall, C. A. ------------------------------------------171 Ratakhin, N. --------------------------------------------355 Ray, A. K. -----------------------------------------------332 Raychaudhuri, T. K. ----------------------------------234 Razhev, A. M.------------------------------------------343 Reardon, P. T. -----------------------------------------163 Reass, W. A. -------------------------------------------175 Redondo, L. M.S. -------------------------------------180 Reed, B. W. --------------------------------------------366 Reed, K. W. --------------------------------------------255 Reess, T.------------------------------------110, 312, 313 Reginato, L. L. -----------------------------------------176 Reinovsky, R. E. --------------------121, 143, 163, 175 Reinovsky, R. R. --------------------------------------144 Ren, C.Y.------------------------------------------------184 Ren, W.--------------------------------------------------278 Renk, T. J. ----------------------------------------146, 248 Repiev, A.G.--------------------------------------------243 Repin, B. G. --------------------------------------------243 Repin, P. B.---------------------------------------243, 244 Reutova, A. G.-----------------------------------193, 294 Reybethbeder, F. -------------------------------------312
Rezchikova, Y. A. -------------------------------------239 Rim, G. H.-----------------------------------------295, 349 Riordan, J. C. ------------------------------------------131 Ritter, S. -------------------------------------------------119 Rizzo, P. N.---------------------------------------------109 Roark, C. ------------------------------------------------214 Roberts, Z. S. ------------------------------------139, 283 Robson, A. E. ------------------------------------------357 Rockey, S. ----------------------------------------------258 Rogers, T. G.-------------------------------------------271 Rolnik, I. A. ---------------------------------------------328 Roman, F.-----------------------------------------------339 Romanov, A. P. ---------------------------------243, 289 Roose, L. D. --------------------------------------------373 Roques, B.----------------------------------------119, 131 Rose, D. V. ---------------------------105, 107, 213, 323 Rose, E. A. ---------------------------------------105, 340 Rose, M. F. ---------------------------------139, 283, 284 Rosol, R. ------------------------------------------132, 211 Rossi, J. -------------------------------------------109, 184 Rostomyan, E. V. -------------------------------------242 Rostov, V. V. -------------------------115, 206, 301, 327 Roth, C. E. ----------------------------------------------138 Rousculp, C. L. ----------------------------------163, 175 Rousseau, A.-------------------------------------------272 Rousskikh, A. ------------------------------------142, 355 Roybal, M. ----------------------------------------------184 Ruan, C.-------------------------------------------------235 Ruden, E. L. --------------------------------------------329 Rudneva, E. S. ----------------------------------------243 Rudys, J. M. --------------------------------------------255 Ruebish, M.---------------------------------------------152 Rui, G. ---------------------------------------------------234 Rukin, S N. ---------------------------------------------161 Runtal, A. S.--------------------------------------------173 Rutberg, P. G. -----------188, 297, 299, 304, 328, 355 Rybachenko, V. F.------------------------------------239 Rybka, D. V.--------------------------------------------191 Ryoo, H. J.----------------------------------295, 349, 358
S Sack, M. -------------------------------------------------315 Sadovoy, A. A.-----------------------------------------239 Saewert, G.---------------------------------------------326 Safronov, A. A. ----------------------------------298, 304 Saito, T. -------------------------------------------------303 Sakamoto, Y.-------------------------------------------314 Sakugawa, T.111, 180, 245, 270, 297, 309, 315, 333,
369 Samek, S.-----------------------------------------------350 Samokhin, A. A. ---------------------------------------121 Sanders, H. D. -----------------------------------229, 330 Sanders, J. M. -----------------------------------------365 Sangwan, K. S. ----------------------------------------346 Sarkar, P. -----------------------------------------291, 335 Sasaki, Y. -----------------------------------------------308 Sasorov, P. V. -----------------------------------------121 Satta, N. -------------------------------------------------308 Savage, E. ----------------------------------------------220 Savage, M. E.------------------132, 221, 232, 238, 322 Savastianov, N. K.------------------------------182, 289
384
Savrun, E.-----------------------------------------------184 Sawhill, S.-----------------------------------------------184 Sawyer, P. S. ------------------------------------------168 Sayapin, A. ---------------------------------------------118 Scapellati, C. -------------------------------------261, 262 Sceifford, M. E. ----------------------------------------255 Schamiloglu, E.--- 116, 117, 174, 184, 197, 205, 213,
255 Scharnholz, S. -----------------------------------236, 237 Schaudinn, C.------------------------------------------278 Schetnikov, E. I. ---------------------------------------289 Schilder, B. ---------------------------------------------340 Schill, Jr., R. A. ----------------------------------------352 Schleher, J.---------------------------------------125, 178 Schlitt, L. G. --------------------------------------------132 Schmidt, J.----------------------------------------------245 Schneider, L. X. ---------------------------------154, 255 Schneider, M. ------------------------------------------256 Schoenbach, K. H.------------------195, 274, 278, 300 Schoeneberg, N. --------------------------------------364 Schramm, T. -------------------------------------------271 Schrock, K. ---------------------------------------------350 Schume, J. W. -----------------------------------------130 Schumer, J. W. ----------------146, 147, 148, 325, 326 Schwartz, T. --------------------------------------------279 Scozzie, C. ---------------------156, 157, 158, 227, 235 Scozzie, S.----------------------------------------------256 Seamen, H. J.------------------------------------------238 Sedghizadeh, P. P.-----------------------------------278 Seidel, D. B. --------------------------------------323, 324 Seiford, M. E. ------------------------------------------132 Selemir, V. D. ------------------------------------243, 244 Selvakumar, S. ----------------------------------------369 Senaj, V. ------------------------------------------------374 Sensenig, R. -------------------------------------------320 Sentoku, Y. ---------------------------------------------120 Serba, E. O. --------------------------------------297, 299 Serebrov, R. A. ----------------------------------------112 Sergeev, A. ---------------------------------------------200 Seta, H.--------------------------------------------------309 Sethi, G. -------------------------------------------------259 Sethian, J. D.-------------------------------153, 214, 357 Sevastyanov, A. S. -----------------------------------289 Sgro, A. G.----------------------------------------------163 Shah, K. G. ---------------------------------------------114 Shaheen, W. -------------------------156, 158, 227, 235 Shan, Y. -------------------------------------------------309 Shao, J.--------------------------------------------------303 Shapovalov, E. V.-------------------------------243, 289 Sharafat, S.---------------------------------------------248 Sharma, A.----------------------------------------248, 332 Sharma, S. K. ------------------------------------114, 332 Sharypov, K. A.----------------------------------193, 294 Shiffler, D.-----------------------------152, 203, 257, 260 Shigeishi, M. -------------------------------------------311 Shimomura, N.-----------------------------------------307 Shin, J. W. ----------------------------------------219, 352 Shirochin, L. A. ----------------------------------------355 Shiryev, V. N. ------------------------------------------298 Shitz, D. V.----------------------------------------------367 Shkuratov, S. I. ----------------------------164, 165, 166 Shmilovitz, D. ------------------------------------------227
Shneerson, G. A. -------------------------------182, 233 Shoenbach, K. H. -------------------------------------275 Shotts, Z. D. --------------------------------139, 283, 284 Shpak, V. G.--------------------------------193, 199, 294 Shpanin, L. M. -----------------------------------------144 Shu, X.---------------------------------------------------275 Shukla, R.-----------------------------------------------114 Shunailov, S. A. ---------------------------------193, 294 Shuto, T. ------------------------------------------------277 Shuttlesworth, R. M.----------------------------------366 Shvetsov, G. A.----------------------------------143, 254 Shyam, A.-----------------------------------------------114 Siemon, R. E. ------------------------------------121, 141 Sigler, J. -------------------------------------------------315 Silvestre de Ferron, A.-------------------------313, 331 Sinclair, M.A. -------------------------------------------190 Sindhu, T. K. -------------------------------------------369 Sinebryukhov, V. A. ----------------------------129, 216 Singer, S. -----------------------------------------------348 Singleton, D. -------------------------------------------286 Sisworahardjo, N. -------------------------------------346 Sitnikova, N. I. -----------------------------------------240 Skakun, V. S. ------------------------------------------367 Skobelev, A. N. ----------------------------------------239 Slenes, K. -----------------------------------------------257 Slough, J. -----------------------------------------------154 Slovikovsky, B. G. ------------------------------------161 Smirnov, V. P. -----------------------------------------121 Smith, I.--------------------------------------------125, 178 Smith, I. D.----------------------------------------------132 Smith, I. R.----------------------------------291, 335, 374 Smith, J. -------------------------------------------104, 169 Smith, J. R. ---------------------------------------------105 Smith, P. W. --------------------------------------------126 Smith, T. R.---------------------------------------------345 Snetov, V. N. -------------------------------------188, 328 So, J. H. -------------------------------------------219, 352 Sofronov, V. N. ----------------------------------------144 Soh, S.---------------------------------------------------255 Solberg, J. M. ------------------------------------------342 Song, C. -------------------------------------------------192 Sosnin, E. A. -------------------------------------------367 Sozer, E. ------------------------------------------------222 Spahn, E. -----------------------------------------236, 237 Speer, R. D. --------------------------------------192, 342 Spencer, J. W. -----------------------------------------144 Spirov, G. M. -------------------------------------------243 Spodobin, V. A.----------------------------------297, 304 Staengle, R. --------------------------------------------315 Stankovic, K. -------------------------------------311, 356 Stavig, M. E.--------------------------------------------168 Stefani, F. -----------------------------------------------251 Stepanenko, Y. ----------------------------------------120 Stepchenko, A. S.-------------------------------------327 Stephanakis, S. J. ------------------------------------148 Stogov, A. Y. -------------------------------------188, 328 Stoltz, P. H.---------------------------------------------214 Stoltzfus, B. S.-----------------------186, 220, 232, 322 Stratton, P. L. ------------------------------------------173 Straus, J. ------------------------------------------------245 Street, R. W. -------------------------------------------372 Stringer, C. ---------------------------------------------171
385
Struve, K. W. -------------------------------------322, 323 Stuart, B. C. --------------------------------------------366 Stukenbrock, L.----------------------------------------315 Stults, A. H.---------------------- 40, 135, 136, 164, 165 Stygar, W. A. -------------129, 132, 152, 221, 323, 327 Suchy, L. ------------------------------------------------336 Suematsu, K.-------------------------------------180, 333 Suen, T. W.---------------------------------185, 201, 310 Sugai, T.-------------------------------------------------308 Sullivan, J. S. ------------------------------------------371 Sun, F. J.------------------------------------------------133 Sun, G. S.-----------------------------------------217, 218 Sun, Y.---------------------------------------------------303 Surov, A. V.---------------------------------297, 299, 304 Swalby, M. E. ------------------------------------372, 373 Swanekamp, S. B. ------------------130, 147, 148, 351 Sze, H.---------------------------------------------125, 178 Szenasi, D. ---------------------------------------------364
T Tabaka, L. J. -------------------------------------------163 Takade, M.----------------------------------------------187 Takahashi, K. ------------------------------------------308 Takahasi, K. --------------------------------------------314 Takaki, K. -----------------------------------296, 308, 314 Takaki, M.-----------------------------------------------311 Talaat, M. -----------------------------------------------191 Talantsev, E. F. ---------------------------164, 165, 166 Tanaka, F. ----------------------------------------------297 Tang, T. -------------------------------159, 262, 263, 362 Tang, W. ------------------------------------------------247 Tang, X. L. ----------------------------------------------317 Tarakanov, V. P. --------------------------------------199 Tarasenko, V. F. --------------------150, 191, 246, 367 Tashima, Y.---------------------------------------------305 Tatsenko, O. M. ---------------------------------243, 289 Temple, R. ----------------------------------------------321 Temple, V. ----------------------156, 157, 158, 227, 235 Teranishi, K.--------------------------------------------307 Terry, R. L.----------------------------------------------255 Thakur, R.-----------------------------------------------234 Thomas, K. J. ------------------------------------------190 Thomas, M.---------------------------------------127, 194 Threadgold, J. -----------------------------------------107 Tierney, T. E.-------------------------------------------163 Timoshkin, I. V. ----------------------------189, 190, 292 Tom, C. Y. ----------------------------------------------321 Tominaga, N.-------------------------------------------315 Tooker, J. F.--------------------------------------------372 Torres, D. T.--------------------------------------------163 Totmeninov, E. M. ------------------------------------206 Toury, M. ------------------------------------------132, 211 Tran, T. --------------------------------------------------257 Triamnak, N. -------------------------------------------171 Tripathi, C. S. ------------------------------------------248 Tripathi, V. K. ------------------------------------215, 248 Trolier-McKinstry, S. ---------------------------------171 Tsyranov, S. N. ----------------------------------------161 Tullar, S. J. ---------------------------------------------255 Tully, L. K. ----------------------------------------192, 342 Turchi, P. J.---------------------------------------------175
Tuttle, B. A.---------------------------------------------168 Tzeng, T. I. ---------------------------------------------201
U Ueda, S. -------------------------------------------------297 Ueno, T. -------------------------------------------111, 303 Uhler, M. D.---------------------------------------------276 Ulmasculov, M. R. ------------------------------193, 294 Upadhyay, A.-------------------------------------------234 Ushich, V. G. -------------------------------------------343
V Vakilian, M. ---------------------------------------------231 Valdivia, M. P. -----------------------------------------241 Valenzuela, J. C. --------------------------------------241 Van De Valde, D. M. ---------------------------129, 255 VanGordon, J. A. -------------------------------------160 Varma, R. -----------------------------------------------346 Vartapetov, S. K. --------------------------------------343 Vasilieva, O. B. ----------------------------------298, 299 Vasyukov, V. A. ---------------------------------------239 Vauchamp, S.------------------------------------------110 Vega, F. -------------------------------------------------339 Vekselman, V. -----------------------------------149, 212 Vekselman, V. V. -------------------------------------215 Veledar, M. ---------------------------------------------230 Veracka, M. J. -----------------------------------------253 Vernier, P. T. -------------------------------------278, 365 Vickers, S. W.------------------------------------------325 Vickers, V. ----------------------------------------------108 Vlasov, Y. V. -------------------------------------243, 289 Vogtlin, G. E.-------------------------------188, 192, 268 Volkov, A. A. -------------------------------------------243 Volkov, G. S. -------------------------------------------121 Vollmer, T. T.-------------------------------------------285 Volodko, A. R. -----------------------------------------243 Vorob'ev, V.S. -----------------------------------------189 Vorobiev, E. --------------------------------------------313 Voumard, N.--------------------------------------------374 Vujisic, M. -----------------------------------------311, 356 Vukic, V.-------------------------------------------------311
W Wacharasindhu, T. -----------------------------------317 Wagoner, T. C. ----------------------------------------322 Wakeland, P. E. ---------------------------------------221 Waldron, W. L.-----------------------------------------176 Walter, J. ------------------------------128, 151, 162, 281 Wang, D. ------------------------------306, 307, 311, 335 Wang, J.-183, 184, 204, 217, 218, 226, 257, 341, 343 Wang, L. S. N. -----------------------------------------223 Wang, P. ------------------------------------------------192 Wang, Q. ------------------------------------------------257 Wang, X. ------------------------123, 181, 221, 317, 376 Ward, K. -------------------------------------------------129 Warren, T. ----------------------------------------125, 178 Watanabe, M. ------------------------------180, 333, 347 Watt, R. G.----------------------------------------------163
386
Watts, C. ------------------------------------------------149 Webb, T. J. ---------------------------------------107, 213 Weber, B. V.--------------------------131, 147, 148, 351 Weed, J. W. --------------------------------------------129 Weeks, V. M.-------------------------------------------181 Weisenburger, A. -------------------------------------211 Welch, D. R.--------------104, 105, 107, 108, 213, 323 Welleman, A.-------------------------------------236, 237 Wetz, D. A. ---------------------------------------251, 252 Wheat, R. M. -------------------------------------336, 358 Wheeler, J. S.------------------------------------------168 White, A. D.---------------------------------------------354 White, D. A.---------------------------------------------342 White, F. E. ---------------------------------255, 372, 373 White, R. ------------------------------------------------152 Whitney, B. A.------------------------------------------132 Wilson, M. P. -------------------------------------190, 292 Winands, G. J. J.--------------------------------176, 306 Wolf, A. --------------------------------------------------315 Wolf, M.--------------------------------------------------348 Wolford, M. F.------------------------------153, 214, 357 Wood, W. M. -------------------------------------------104 Woods, A. J.--------------------------------------------207 Woodworth, J. R.--------------------------129, 152, 238 Wright, S. -----------------------------------------------120 Wu, A.----------------------------------------------------318 Wu, H. Y.------------------------------------------------133 Wu, Y. H.------------------------------------------------365 Wyndham, E. S. ---------------------------------------241
X Xavier, C. C.--------------------------------------------208 Xiao, S. --------------------------------------------195, 274 Xie, W. ---------------------------------------------221, 376
Y Yakubov, V. B.-----------------------------------144, 240 Yalandin, M. E. ----------------------------------193, 294 Yalandin, M. I. -----------------------------------------199 Yalov, V.-------------------------------------------------218 Yamabe, C.---------------------------------------------316 Yamamoto, T.------------------------------------------245 Yamanaka, S.------------------------------------------307 Yamazaki, N.-------------------------------------------314 Yan, H.---------------------------------------------------280 Yan, K.---------------------------------------------176, 280 Yan, P.---------183, 184, 217, 218, 226, 303, 341, 343 Yanenko, V. A. ----------------------------------------289 Yang, H. L.----------------------------------------------133 Yang, K. S. ---------------------------------------------113 Yang, X. H. ---------------------------------------------256 Yang, X. J. ----------------------------------------------137 Yankelevich, Y. ----------------------------------------348 Yano, K. I.-----------------------------------------------277 Yano, M.-------------------------------------------------299
Yano, T. -------------------------------------------------307 Yarin, P. M. ---------------------------------------113, 127 Yarmolich, D.-------------------------------------149, 215 Yasui, D. ------------------------------------------------245 Yeckel, C. -----------------------------------------------271 Yokote, Y.-----------------------------------------------307 Young, A. -----------------------------------------162, 290 Young, F. C.--------------------------------------147, 148 Yu, C. Y.-------------------------------------------------137 Yuan, J.--------------------------------------------221, 376 Yuan, W. Q. --------------------------------184, 341, 343
Z Zabihi, S. ------------------------------------------337, 338 Zaccarian, L. -------------------------------------------174 Zagulov, P. ---------------------------------------------218 Zaitsev, V. I.--------------------------------------------121 Zakrevsky, D. E.---------------------------------------343 Zare, F. --------------------------------------------337, 338 Zellers, B. -----------------------------------------------258 Zhakov, S. V.-------------------------------------------199 Zhang, D. D.--------------------------------------184, 226 Zhang, G. W.-------------------------------------------133 Zhang, H. -----------------------------------------------204 Zhang, J. ------------------------------------------------157 Zhang, Q. -----------------------------------------170, 258 Zhang, S.------------------------------------------170, 258 Zhang, Y.------------------------------------------------149 Zhao, C. -------------------------------------------------219 Zhao, H. -------------------------------------------------313 Zhao, Q. -------------------------------------------------137 Zhao, T. -------------------------------------------------123 Zhao, Y. -------------------------------------------------123 Zharkova, L. P. ----------------------------------------301 Zharova, N. ---------------------------------------------355 Zhou, K. -------------------------------------------------170 Zhou, L.--------------------------------------------------322 Zhou, X. -------------------------------------------------170 Zhou, Y. -------------------------------------226, 341, 343 Zhu, L. ---------------------------------------------------257 Zhuang, J. ----------------------------------------278, 300 Zhupikov, A. A. ----------------------------------------343 Zier, J. ---------------------------------213, 231, 247, 282 Zirnheld, J. L. ------------------------------185, 302, 370 Ziska, D.-------------------------------------------------107 Zmushko, V. V. ----------------------------------------239 Zo, C. ----------------------------------------------------170 Zorngiebel, V. ------------------------------------236, 237 Zou, C.---------------------------------------------------258 Zou, W. --------------------------------------------------322 Zou, X. ---------------------------------------------------123 Zubaerova, R. R.--------------------------------------239 Zucchini, F. ---------------------------------------------119 Zutavern, F. J. -----------------------------------372, 373 Zykov, V. V. --------------------------------------------254
387
Sponsors of the IEEE 2009 Pulsed Power Conference
388
Technical Session Guide
Oral Session Technical Area Session Name
E-Beam Driven X-Ray Sources
Session O1 Charged Particle Beams and
Sources (CPBS)
Session O2 Explosive and Compact Pulsed Power (ECPP) Compact Pulsed Power
Session O3 Microwave and RF Sources (MRFS)
Narrow Band and Electron Devices
Session O4 High Energy Density Plasmas (HEDP)
High Energy Density Plasmas – Z Pinches
Session O5 Microwave and RF Sources(MRFS) RF/HPM Systems and Effects
Pulsed Power Sources – High Current Accelerators Session O6 Pulsed Power Sources (PSOR)
Session O7 Explosive and Compact Pulsed Power (ECPP) Explosive Pulsed Power 1
Session O8 High Energy Density Plasmas (HEDP)
High Energy Density Plasmas – Applications
Session O9 Charged Particle Beams and Sources (CPBS)
Intense Electron and Ion Beams and Plasmas
Pulsed Power Switches & Components – Closing
Switches Session O10 Pulsed Power Switches and
Components (PPSC) Pulsed Power Switches & Components – Solid State
Switches Session O11 Pulsed Power Switches and
Components (PPSC)
Session O12 Explosive and Compact Pulsed Power (ECPP) Explosive Pulsed Power 2
Session O13 Dielectrics and Energy Storage (DES) Advanced Dielectrics
Session O14 Pulsed Power Systems (PPSY) Pulsed Power Systems
389
Repetitive Pulsed Power and High Current Pulsers Session O15 Pulsed Power Sources (PSOR)
Electromagnetic Launchers and Pulsed Power Systems Session O16 Pulsed Power Systems (PPSY)
Session O17 Dielectrics and Energy Storage (DES) Pulsed Power Capacitors
Session O18 Power Electronics and Systems (PES)
Power Electronics and Systems
Session O19 Dielectrics and Energy Storage (DES)
Breakdown Phenomena in Gases, Liquids, & Solids
Session O20 Industrial, Commercial, and Medical Applications (ICMA)
Industrial, Commercial, and Medical Applications
Session O21 Industrial, Commercial, and Medical Applications (ICMA)
Industrial, Commercial, and Medical Applications
Session O22 Pulsed Power Switches and Components (PPSC)
Bulk Optical Switches and Components
Poster Session Technical Areas and Session Names
Microwave & RF Sources; Charged Particle Beams & Sources; Dielectrics & Energy Storage (MRFS, CPBS, DES) Session 01P
High Energy Density Plasmas; Pulsed Power Switches & Components (HEDP, PPSC) Session 02P
Industrial, Commercial, & Medical Applications; Explosive and Compact Pulsed Power (ICMA, ECPP) Session 03P
Pulsed Power Sources; Pulsed Power Systems; Diagnostics; Power Electronics and Systems (PSOR, PPSY, DIA, PES) Session 04P
390
MAP OF HOTEL
391