1 ILC DR Workshop - KEK18-20 December, 2007

A new resonance in wiggler simulations: Christine Celata

Bldg 4 Rm 345

Bldg 4 Rm 345

Lunch

Coffee

Discussion: EDR Deliv and Sched

Celata (WebEx; 25'); Wang (WebEx; 15');

Demma (25'); Suetsugu (25')

Ohnishi (25'); Hyunchang (15'); Flanagan (25'); Terunuma (25')

Use POSINST code

2 ILC DR Workshop - KEK18-20 December, 2007

A new resonance in wiggler simulations

3 ILC DR Workshop - KEK18-20 December, 2007

A new resonance in wiggler simulations: Christine Celata

4 ILC DR Workshop - KEK18-20 December, 2007

Build-up simulations in wiggler: Lanfa Wang

5 ILC DR Workshop - KEK18-20 December, 2007

Build-up simulations in wiggler

Use CLOUDLAND code

6 ILC DR Workshop - KEK18-20 December, 2007

Secondary emission in grooves: Lanfa Wang

7 ILC DR Workshop - KEK18-20 December, 2007

Instability in Daphne positron ring: Theo Demma

8 ILC DR Workshop - KEK18-20 December, 2007

Build-up simulations for Daphne: Theo Demma

Use ECLOUD code

9 ILC DR Workshop - KEK18-20 December, 2007

R. Cimino Frascati

Updates on experimental work at Frascati

10 ILC DR Workshop - KEK18-20 December, 2007

Mitigation techniques tests in KEKB: Yusuke Suetsugu

11 ILC DR Workshop - KEK18-20 December, 2007

Mitigation techniques tests in KEKB: Yusuke Suetsugu

12 ILC DR Workshop - KEK18-20 December, 2007

Mitigation techniques tests in KEKB: Yusuke Suetsugu

13 ILC DR Workshop - KEK18-20 December, 2007

Mitigation techniques tests in KEKB: Yusuke Suetsugu

14 ILC DR Workshop - KEK18-20 December, 2007

KEKB for ILC studies, simulation low emittance lattice: Y. Onishi

Use SAD code

15 ILC DR Workshop - KEK18-20 December, 2007

KEKB for ILC studies, simulation low emittance lattice

16 ILC DR Workshop - KEK18-20 December, 2007

KEKB for ILC studies, simulation low emittance lattice: Y. Onishi

17 ILC DR Workshop - KEK18-20 December, 2007

Ecloud instability simulations for CesrTA: Jin Hyunchang

Use PEHTS code

18 ILC DR Workshop - KEK18-20 December, 2007

Ecloud instability simulations for CesrTA

19 ILC DR Workshop - KEK18-20 December, 2007

Ecloud instability simulations for CesrTA : Jin Hyunchang

20 ILC DR Workshop - KEK18-20 December, 2007

KEKB for ILC, X-ray beam size monitors: John Flanagan

21 ILC DR Workshop - KEK18-20 December, 2007

KEKB for ILC, X-ray beam size monitors: John FlanaganU

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22 ILC DR Workshop - KEK18-20 December, 2007

KEKB for ILC, X-ray beam size monitors: John Flanagan

23 ILC DR Workshop - KEK18-20 December, 2007

Fast Ion Instability at KEK-ATF: N. Terunuma

24 ILC DR Workshop - KEK18-20 December, 2007

Fast Ion Instability at KEK-ATF: N. Terunuma

25 ILC DR Workshop - KEK18-20 December, 2007

Parallel session 1h discussion:

• Milestones to ILC Engineering Design Report (EDR) and

• R&D work plans for the EDR

26 ILC DR Workshop - KEK18-20 December, 2007

Milestones to ILC EDR

o Test coating techniques and determine conditioning effectiveness in existing accelerator beam lines

o Select coatings in different regions of damping ring: TiN with respect to TiZrV non-evaporable getter NEG

o Characterize thin-film coating durability after long term exposure to beam in operating conditions:

• analyze PEP-II TiN-chambers after ~10 years operation (Pivi - 09/08)• analyze ESRF NEG-chambers (Palmer to give a call to Roberto)• wiggler test at KEKB (Suetsugu -09/08) and CesrTA (Palmer -

09/08)

o Need to experimentally characterize Photoemission in ILC DR parameters range to estimate initial electron density (EuroTeV 2009)

o Characterize the electron cloud build-up by simulations and measurements in existing accelerators

The goal is to complete the following tasks by early 2010 as input for the Engineering Design Report (EDR)

27 ILC DR Workshop - KEK18-20 December, 2007

Milestones to EDRo Model the electron cloud in wigglers and quadrupoles

o Characterize the electron cloud instability by measurements in existing facilities possibly also at CesrTA, KEKB operating at ultra-low emittancies

o Model the ILC DR electron cloud instability by simulations

Evaluate the need for Additional Mitigation techniques (besides coating):

o Test clearing electrodes in magnetic field regions: in wigglers at KEKB and CESR and in dipoles at PEP-II and SPS

o Test triangular groove or slots in magnetic field regions: in wigglers at KEKB and CESR and in dipoles at PEP-II and SPS

o Characterize the impedance and HOMs of mitigation techniques

o Decide on use of antechambers and select where they are needed

o Specify electron cloud mitigation requirements for straight, quadrupole, wiggler and bend sections

Recommendation of mitigation techniques to prevent the electron cloud in the ILC damping ring as input for the EDR

28

Suggested to have further meeting to discuss the Milestones chart above, include more details and agree upon “who is working on what” at the next electron-cloud WebEx meeting proposed for:

Tuesday 15th January 2008 (6AM SLAC time..)

29

Electron cloud: Milestones (Cornell 2006)

Test clearing electrodes(a) characterize impedance, HOM, power loadanalytical estimatessimulate MAFIA, A. Krasnyhk, Cho Ngsimulate with VORPAL, V. Ivanov (?)simulate, F. Caspers

(b) machine studiestest in HCX in a quadrupole or drift region, A. Molviktest in ESA preliminary to PEPII installation, M. Pivi, test in PEPII in bend chicane, M. Pivi

test in CESR in wiggler section, M. Palmertest in KEKB arc section bend or wiggler section, Y. Suetsugutest in LHC arc section bend section, F. Caspers

(c) develop diagnostic electron cloud diagnostic for test chambers, A. Molvik electron cloud diagnostic for test chambers, R. Macek

Model for “who is working on what”:

that we agreed upon at Cornell

Workshop 2006

30

R&D work plans for the EDR

From “Damping Rings EDPhase Gantt Links” document

On above table:“30. Specify baseline for e-cloud mitigation techniques” is for summer 2008, although experiments on mitigations will be still underway or just started …

We decided to start working now on vacuum design and give our best guess at this stage for possible mitigation techniques: coatings, antechamber, grooves, clearing electrodes in each magnetic field region.

31

Bootstrap on recommendation for mitigation and work on vacuum design

DR element Antechamber Coating Mitigation Remarks

STRAIGHT Yes in arcs and wigglers

NEG Solenoid if necessary

BEND Yes NEG Grooves or Electrodes

NEG if good enough for ECE

WIGG Yes NEG Electrodes or Grooves

QUAD Yes in arcs and wigglers

NEG T.b.d.

This preliminary table is our best guess at this stage, for colleagues to work on and give their feedback, with the goal to ”Specify baseline for e-cloud mitigation techniques” by the (end of) summer 2008.

Notes: TiN is a strong candidate instead of NEG. In STRAIGHTS we are debating the use of grooves and solenoids as additional mitigation.