international linear colllider global design effort barry barish slac ilc group 5-may-05
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International Linear Colllider
Global Design Effort
Barry BarishSLAC ILC Group
5-May-05
5-May-05 SLAC 2
main linacbunchcompressor
dampingring
source
pre-accelerator
collimation
final focus
IP
extraction& dump
KeV
few GeV
few GeVfew GeV
250-500 GeV
Starting Point
Superconducting RF Main Linac
5-May-05 SLAC 3
“Target” Parameters for the ILC
• Ecm adjustable from 200 – 500 GeV
• Luminosity ∫Ldt = 500 fb-1 in 4 years
• Ability to scan between 200 and 500 GeV
• Energy stability and precision below 0.1%
• Electron polarization of at least 80%
• The machine must be upgradeable to 1 TeV
5-May-05 SLAC 4
TESLA Concept
• The main linacs based on 1.3 GHz superconducting technology operating at 2 K.
• The cryoplant, is of a size comparable to that of the LHC, consisting of seven subsystems strung along the machines every 5 km.
5-May-05 SLAC 5
TESLA Cavity
• RF accelerator structures consist of close to 21,000 9-cell niobium cavities operating at gradients of 23.8 MV/m (unloaded as well as beam loaded) for 500 GeV c.m. operation.
• The rf pulse length is 1370 µs and the repetition rate is 5 Hz. At a later stage, the machine energy may be upgraded to 800 GeV c.m. by raising the gradient to 35 MV/m.
5-May-05 SLAC 6
TESLA Single Tunnel Layout
• The TESLA cavities are supplied with rf power in groups of 36 by 572 10 MW klystrons and modulators.
5-May-05 SLAC 7
Reference Points for the ILC Design
33km47 km
TESLA TDR500 GeV (800 GeV)
US Options Study500 GeV (1 TeV)
5-May-05 SLAC 8
Experimental Test Facility - KEK
• Prototype Damping Ring for X-band Linear Collider
• Development of Beam Instrumentation and Control
5-May-05 SLAC 9
Evaluation: Technical Issues
5-May-05 SLAC 10
TESLA Test Facility Linac
laser driven electron gun
photon beam diagnostics
undulatorbunch
compressor
superconducting accelerator modules
pre-accelerator
e- beam diagnostics
e- beam diagnostics
240 MeV 120 MeV 16 MeV 4 MeV
5-May-05 SLAC 11
ILC Design Issues
First Consideration : Physics Reach
ILC Parameters
Energy Reach
2cm fill linac RFE b L G
Luminosity RF AC BS
cm y
PL
E
5-May-05 SLAC 12
Working Parameter Set“Point Design”
Center of Mass Energy 500 1000 GeV
Design Luminosity 2 3 1034cm-2sec-1
Linac rf frequency GHzAccelerating gradient MV/mPulse repetition rate HzBunches/pulseBunch separation nsec
Particles/bunch x1010
Bunch train length msecBeam power 11 23 MW/beam
sx/sy at IP 655/7 554/4 nm
Site AC power 180 356 MW
5
1.3
2866
2820307
30
5-May-05 SLAC 13
GDE will do a “Parametric” Design
nom low N lrg Y low P
N 1010 2 1 2 2
nb2820 5640 2820 1330
ex,ymm, nm 9.6, 40 10,30 12,80 10,35
bx,ycm, mm 2, 0.4 1.2, 0.2 1, 0.4 1, 0.2
sx,ynm 543, 5.7 495, 3.5 495, 8 452, 3.8
Dy18.5 10 28.6 27
dBS% 2.2 1.8 2.4 5.7
szmm 300 150 500 200
PbeamMW 11 11 11 5.3
L 1034 2 2 2 2
Range of parametersdesign to achieve 21034
5-May-05 SLAC 14
Maximum Luminosity
nom low N lrg Y low P High L
N 1010 2 1 2 2 2
nb 2820 5640 2820 1330 2820
x,y mm, nm 9.6, 40 10,30 12,80 10,35 10,30
x,y cm, mm 2, 0.4 1.2, 0.2 1, 0.4 1, 0.2 1, 0.2
sx,y nm 543, 5.7 495, 3.5 495, 8 452, 3.8 452, 3.5
Dy 18.5 10 28.6 27 22
BS % 2.2 1.8 2.4 5.7 7
sz mm 300 150 500 200 150
Pbeam MW 11 11 11 5.3 11
L 1034 2 2 2 2 4.9!
5-May-05 SLAC 15
Towards the ILC Baseline Design
5-May-05 SLAC 16
e- Beam Transport XFEL
e- Damping Ring
HEP & XFEL Experiments
e- Main LINAC e+ Beam delivery e+ Main LINAC
e+ Damping Ringe- Sources e+ Beam Transport
e- Beam delivery
e+ Source
e- Switchyard XFEL
PreLinac
PreLinac
Beam DumpsDESY site Westerhorn
TESLA machine schematic view
Power Water & Cryogenic Plants
Machine cost distribution
Main LINAC Modules
Main LINAC RF System
Civil Engineering
MachineInfrastructure
X FELIncrementals
Damping Rings
HEP Beam Delivery
AuxiliarySystems
Injection System
1131
~ 33 km
587 546
336241 215
124 101 97
Million Euro
TESLA Cost Estimate3,136 M€ (no contingency, year 2000) + ~7000 person years
5-May-05 SLAC 17
RF SC Linac ChallengesEnergy: 500 GeV, upgradeable to 1000 GeV
• RF Accelerating Structures– Accelerating structures must support the desired gradient in an
operational setting and there must be a cost effective means of fabrication.
– ~17,000 accelerating cavities/500 GeV
– Current performance goal is 35 MV/m, (operating at 30 MV/m)
• Trade-off cost and technical risk.
1 mRisk
Cos
t
~T
heor
etic
al M
ax
5-May-05 SLAC 18
(Improve surface quality -- pioneering work done at KEK)
BCP EP
• Several single cell cavities at g > 40 MV/m
• 4 nine-cell cavities at ~35 MV/m, one at 40 MV/m
• Theoretical Limit 50 MV/m
Electro-polishing
5-May-05 SLAC 19
Gradient
Results from KEK-DESY collaboration
must reduce spread (need more statistics)
single
-cell
measu
rem
ents
(in
nin
e-c
ell
cavit
ies)
5-May-05 SLAC 20
New Cavity Shape for Higher Gradient?
TESLA Cavity
• A new cavity shape with a small Hp/Eacc ratio around35Oe/(MV/m) must be designed. - Hp is a surface peak magnetic field and Eacc is the electric field gradient on the beam axis.
- For such a low field ratio, the volume occupied by magnetic field in the cell must be increased and the magnetic density must be reduced.
- This generally means a smaller bore radius. - There are trade-offs (eg. Electropolishing, weak cell-to-cell
coupling, etc)
Alternate Shapes
5-May-05 SLAC 21
Gradient vs Length
• Higher gradient gives shorter linac – cheaper tunnel / civil engineering– less cavities – (but still need same # klystrons)
• Higher gradient needs more refrigeration– ‘cryo-power’ per unit length scales as G2/Q0
– cost of cryoplants goes up!
5-May-05 SLAC 22
Klystron Development
THALUS
CPITOSHIBA
10MW 1.4ms Multibeam Klystrons~650 for 500 GeV+650 for 1 TeV upgrade
5-May-05 SLAC 23
Towards the ILC Baseline Design
Not cost drivers
But can be L performancebottlenecks
Many challenges!
5-May-05 SLAC 24
Parameters of Positron Sources
rep rate# of bunches per pulse
# of positrons per bunch
# of positrons per pulse
TESLA TDR 5 Hz 2820 2 · 1010 5.6 · 1013
NLC 120 Hz 192 0.75 · 1010 1.4 · 1012
SLC 120 Hz 1 5 · 1010 5 · 1010
DESY positron source
50 Hz 1 1.5 · 109 1.5 · 109
5-May-05 SLAC 25
Positron Source
• Large amount of charge to produce
• Three concepts:– undulator-based (TESLA TDR baseline)
– ‘conventional’ – laser Compton based
5-May-05 SLAC 26
5-May-05 SLAC 27
5-May-05 SLAC 28
5-May-05 SLAC 29
Strawman Final Focus
5-May-05 SLAC 30
International/Regional Organization
ILC-Americas Regional Team Regional Director and Deputy Institutional ILC Managers for major instiutional members
CornellILC-NSF PI
TRIUMFILC-CanadaManager
NSF-funded Institutions
Canadian Institutions
Lead Labs
Work Package
Oversight ILCSC
GDE - Director
RegionalUSLCSG
FundingAgencies
FNALILC-FNALManager
WP 1.FNAL
WP 1.ANL
WP 3.FNAL
SLACILC-SLACManager
WP 2.SLAC
WP 2.BNL
WP 3.SLAC
communications
ILC-Asia ILC-Europe
International
Regional
5-May-05 SLAC 31
Fall 2002: ICFA created the International Linear Collider Steering Committee (ILCSC) to guide the process for building a Linear Collider. Asia, Europe and North America each formed their own regional Steering Groups (Jonathan Dorfan chairs the North America steering group).
Physics and Detectors Subcommittee (AKA WWS) Jim Brau, David Miller, Hitoshi Yamamoto, co-chairs (est. 1998 by ICFA as free standing group)
International Linear Collider Steering CommitteeMaury Tigner, chair
ParametersSubcommitteeRolf Heuer, chair
(finished)
Accelerator SubcommitteeGreg Loew, chair
Comunicationsand OutreachNeil Calder et al
Technology Recommendation Panel
Barry Barish, chair (finished)
Global Design Initiative
organization Satoshi Ozaki, chair (finished)
GDI central team site
evaluation Ralph Eichler,
chair
GDI central team director
search committee Paul Grannis,
chair
5-May-05 SLAC 32
Attendees: Son (Korea); Yamauchi (Japan); Koepke (Germany); Aymar (CERN); Iarocci (CERN Council); Ogawa (Japan); Kim (Korea); Turner (NSF - US); Trischuk (Canada); Halliday (PPARC); Staffin (DoE – US); Gurtu (India)
Guests: Barish (ITRP); Witherell (Fermilab Director,)
“The Funding Agencies praise the clear choice by ICFA. This recommendation will lead to focusing of the global R&D effort for the linear collider and the Funding Agencies look forward to assisting in this process.
The Funding Agencies see this recommendation to use superconducting rf technology as a critical step in moving forward to the design of a linear collider.”
FALC is setting up a working group to keep a close liaison with the Global Design Initiative with regard to funding resources.
The cooperative engagement of the Funding Agencies on organization, technology choice, timetable is a very strong signal and encouragement.
Working with Funding Agency (FALC)
5-May-05 SLAC 33
GDE – Near Term Plan
• Organize the ILC effort globally– Undertake making a “global design” over the next few years
for a machine that can be jointly implemented internationally. • Snowmass Aug 05 --- Begin to define Configuration (1st Step)
• GDE Dec 05 --- Baseline Configuration document by end of 2005
• Put Baseline under Configuration Control
• Conceptual Design of Baseline by end of 2006– Include site dependence – 3 or more sample sites– Detector Design Concept / Scope (1 vs 2, options, etc)– Reliable Costs -- emphasis during design on cost consciousness ---
value Engineering, trade studies, industrialization, etc
– Coordinate worldwide R & D efforts, in order to demonstrate and improve the performance, reduce the costs, attain the required reliability, etc. (Proposal Driven to GDE)