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Linear Collider – Next Steps in R&D. Nan Phinney SLAC. many slides courtesy of G. Geshonke EPS 2009 C. Adolphsen, F. Zimmermann and others. Linear Collider Luminosity. n b : bunches / train N: Particles / bunch A: beam cross section at IP H D : beam-beam enhancement factor. where. - PowerPoint PPT Presentation
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Linear Collider – Next Steps in R&D
Nan PhinneySLAC
many slides courtesy of G. Geshonke EPS 2009
C. Adolphsen, F. Zimmermann and others
2009 SLUO Meeting Sept 17, 2009 Page 2
Linear Collider Luminosity
nb : bunches / train
N: Particles / bunchA: beam cross section at IPHD: beam-beam enhancement factor
BUT Pbeam = Pwall plug * ηconversion efficiency
two-linac length 2L ~ ECM/(Ffilling factor x Ggradient)
This points to the critical issues in optimizing the cost of the collider→ Efficiency sets the electrical power required for a given beam power → Accelerating gradient sets the length required for a given energy
ILC & CLIC take different routes to high efficiency and high gradient
where
2009 SLUO Meeting Sept 17, 2009 Page 3
The ILC Reference Design
200-500 GeV centre-of-massLuminosity: 2×1034 cm-2s-1
Based on accelerating gradient of 31.5 MV/m(1.3GHz SCRF)
~31 km
N.Walker
2009 SLUO Meeting Sept 17, 2009 Page 4
SCRF Technology Required
Parameter Value
C.M. Energy 500 GeV
Peak luminosity 2x1034 cm-2s-1
Beam Rep. rate 5 Hz
Pulse time duration 1 ms
Average beam current 9 mA (in pulse)
Av. field gradient 31.5 MV/m# 9-cell cavity 14,560# cryomodule 1,680# RF units 560
A. Yamamoto
2009 SLUO Meeting Sept 17, 2009 Page 5
R. Geng, JLab
BREAKING NEWS !!!!
JLAB press release today announced the first US built cavity to reach ILC specs
2009 SLUO Meeting Sept 17, 2009 Page 6
SRF Test Facilities
KEK, JapanDESYFNAL
TTF/FLASH~1 GeVILC-like beamILC RF unit(* lower gradient)
NML facilityUnder constructionfirst beam 2010ILC RF unit test
STF (phase I & II)Under constructionfirst beam 2011ILC RF unit test
A. Yamamoto
2009 SLUO Meeting Sept 17, 2009 Page 7
New L-Band Station at ESB: Marx Modulator and 10 MW Toshiba Multi-Beam Klystron
C. Adolphsen
2009 SLUO Meeting Sept 17, 2009 Page 8
Sheet Beam Klystron Development
An elliptical beam is focused in a periodic permanent magnet stack that is interspersed with rf cavities
ElectronBeam
PermanentMagnet Cell
RF cavity
Magnetic Shielding
Lead Shielding
Gun in assembly
2009 SLUO Meeting Sept 17, 2009 Page 9
Coupler Assembly and Processing
Class 10 Cleanroom @SLAC
Processed in pairs – shipped
to FNAL
2009 SLUO Meeting Sept 17, 2009 Page 10
RF Distribution Modules with variable tap off
Variable tap off allows power adjustment to each cavity
4 2-cavity modules sent to FNAL
2009 SLUO Meeting Sept 17, 2009 Page 11
Two 4.5 to 5.5 m diameter tunnels spaced by ~7 m.
RDR Baseline Tunnel Layout
Accelerator Tunnel Service TunnelPenetrations(every ~12 m)
one klystron feeding 26 cavities
C. Adolphsen
2009 SLUO Meeting Sept 17, 2009 Page 12
Klystron Cluster Concept
RF power “piped” into accelerator tunnel every 2.5 km
Service tunnel eliminated
Electrical and cooling systems simplified
Concerns: power handling, LLRF control coarseness
Same as baseline
C. Adolphsen
2009 SLUO Meeting Sept 17, 2009 Page 14 14
ILC R&D plan
2009 SLUO Meeting Sept 17, 2009 Page 15
The CLIC Two Beam Scheme
Two Beam Scheme:Drive Beam supplies RF power
• 12 GHz bunch structure• low energy (2.4 GeV - 240 MeV)• high current (100A)
CLIC parameters:
Accelerating gradient: 100 MV/m RF frequency: 12 GHzPulse length 240 ns, 50 Hz
active length for 1.5 TeV: 15 km
G. Geshonke
2009 SLUO Meeting Sept 17, 2009 Page 16
CLIC Drive Beam generation
EPS 2009 G.Geschonke, CERN
Accelerate long bunch train with low bunch rep rate (500 MHz) with low frequency RF (1 GHz) (klystrons)
interleave bunches between each otherto generate short (280 ns) trains with high bunch rep rate (12 GHz)
G. Geshonke
2009 SLUO Meeting Sept 17, 2009 Page 17
The full CLIC scheme
e+ injector, 2.4 GeV
e- injector2.4 GeV
CLIC 3 TeV
e+ main linace- main linac , 12 GHz, 100 MV/m, 21.02 km
BC2BC2
BC1
e+
DR365m
e-
DR365m
booster linac, 9 GeV
decelerator, 24 sectors of 876 m
IP
BDS2.75 km
BDS2.75 km
48.3 km
drive beam accelerator2.38 GeV, 1.0 GHz
combiner rings Circumferences delay loop 72.4 m
CR1 144.8 mCR2 434.3 m
CR1CR2
delayloop
326 klystrons33 MW, 139 s
1 km
CR2delayloop
drive beam accelerator2.38 GeV, 1.0 GHz
326 klystrons33 MW, 139 s
1 km
CR1
TAR=120m
TAR=120m
245m 245m
e+
PDR365m
e-
PDR365m
e+ injector, 2.4 GeV
e- injector2.4 GeV
CLIC 3 TeV
e+ main linace- main linac , 12 GHz, 100 MV/m, 21.02 km
BC2BC2
BC1
e+
DR365m
e-
DR365m
booster linac, 9 GeV
decelerator, 24 sectors of 876 m
IP
BDS2.75 km
BDS2.75 km
48.3 km
drive beam accelerator2.38 GeV, 1.0 GHz
combiner rings Circumferences delay loop 72.4 m
CR1 144.8 mCR2 434.3 m
CR1CR2
delayloop
326 klystrons33 MW, 139 s
1 km
drive beam accelerator2.38 GeV, 1.0 GHz
combiner rings Circumferences delay loop 72.4 m
CR1 144.8 mCR2 434.3 m
CR1CR1CR2
delayloop
326 klystrons33 MW, 139 s
1 km
CR2delayloop
drive beam accelerator2.38 GeV, 1.0 GHz
326 klystrons33 MW, 139 s
1 km
CR1CR1CR1
TAR=120m
TAR=120m
245m 245m
e+
PDR365m
e-
PDR365m
Not to scale! G. Geshonke
2009 SLUO Meeting Sept 17, 2009 Page 18
optimum CLIC: 100 MV/m at 12 GHz
Structure limits: • RF breakdown – scaling• RF pulse heating
Optimisation:
Beam dynamics:• emittance preservation – wake fields• Luminosity, bunch population, bunch spacing• efficiency – total powerFigure of merit:• Luminosity per linac input powertake into account cost model
100 MV/m 12 GHz chosen,previously 150 MV/m, 30 GHz
A. Grudiev
2009 SLUO Meeting Sept 17, 2009 Page 19
CLIC Accelerating Module
19
Drive Beam
Main Beam
Transfer lines
Main Beam
Drive Beam
G. Riddone
2009 SLUO Meeting Sept 17, 2009 Page 20
CLIC Accelerating structures
Technologies:Brazed disks - milled quadrants
Objective:• Withstand 100 MV/m without damage• breakdown rate < 10-7
• Strong damping of HOMs
Collaboration: CERN, KEK, SLACW. Wunsch
2009 SLUO Meeting Sept 17, 2009 Page 21
Nominal performance of Accelerating StructuresDesign@CERN, Built/Tested @KEK, SLAC
95 100 105 110 11510
-7
10-6
10-5
10-4
Unloaded Gradient: MV/m
BK
D R
ate:
1/p
ulse
/m
BKD Rate for 230ns
250hrs
500hrs
1200hrs
900hrs
CLIC target
KEK
SLAC
2009 SLUO Meeting Sept 17, 2009 Page 22
Power Extraction : PETS
8 Sectorsdampedon-off possibility
Status:CTF3: up to 45 MW peak (3 A beam,recirculation)SLAC: 125 MW @ 266 ns
Special development for CLIC
Travelling wave structures Small R/Q : 2.2 kW/m (accelerating structure: 15-18 kW/m) 100 A beam current
136 MW RF @ 240 ns per PETS (2 accelerating structures)0.21 m active lengthtotal number : 35’703 per linac
I. Syratchev
2009 SLUO Meeting Sept 17, 2009 Page 23
Power Extraction Structures (PETS)
(Previously considered PETS a significant risk)
160
180
200
Pow
er [M
W]
12.0
5.09
TBTS PETS,140 ns flat,25 minutes.
135 MW (CLIC 3 TeV target)
153 MW (CLIC 0.5 TeV target)
266 ns 266 ns133 ns
150 Hours 210 Hours
PETS 1st run (winter 2008/09) PETS 2nd run (May 2009…)
F. Zimmermann
2009 SLUO Meeting Sept 17, 2009 Page 24
CLIC Test Facility CTF3
Provide answers for CLIC specific issues Write CDR in 2010
Two main missions:
Prove CLIC RF power source scheme:• bunch manipulations, beam stability,• Drive Beam generation• 12 GHz extraction
Demonstration of “relevant” linac sub-unit:• acceleration of test beam
Provide RF power for validation of CLIC components: accelerating structures, RF distribution, PETS (Power extraction and Transfer Structure)
G. Geshonke
2009 SLUO Meeting Sept 17, 2009 Page 25
CTF3 building blocks
150 MeV e-linac
PULSE COMPRESSIONFREQUENCY MULTIPLICATION
CLEX (CLIC Experimental Area)TWO BEAM TEST STAND
PROBE BEAMTest Beam Line
3.5 A - 1.4 s
28 A - 140 ns
30 GHz test stand
Delay LoopCombiner Ring
D FFD
D F DD F D D F D
D F D
DF DF DF DF DF DF DF DF DF
D F DF DF D
D FFFDD
D F DD F DD F DD F D D F DD F D
D F DD F D
DF DF DF DF DF DF DF DF DF DFDF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF
D F DD F DF DF DF DF D
total length about 140 m
magnetic chicane
10 m
Photo injector tests,laser
Infrastructure from LEP
G. Geshonke
2009 SLUO Meeting Sept 17, 2009 Page 26
Delay Loop
circumference 42 m (140 ns)isochronous opticswiggler to tune path length (9 mm range)
1.5 GHz RF deflector
Designed and built by INFN Frascati
G. Geshonke
2009 SLUO Meeting Sept 17, 2009 Page 28
Other R&D on performance issues
R&D on Damping Rings and Beam Deliveryin other test facilities:
CESR-TA at Cornell: Electron Cloud mitigation and low emittance tuning
ATF/ATF2 at KEK: Low emittance damping ringFinal focus test facility to demonstratenanometer beam sizes and stability
2009 SLUO Meeting Sept 17, 2009 Page 29
Electron cloud mitigation R&D: PEP-II chicane
TiN surface much reduced signal with respect to Al
Observed new resonance: Electron current peaks at defined B values (n)
Test chamber Al and TiN-coated
New 4-dipole chicane in the PEP-II LER
Mitigation tests in ILC magnetic field
Aluminum surface
M. Pivi
2009 SLUO Meeting Sept 17, 2009 Page 30
ILC Damping Ring R&D
Lattice design for baseline positron ringLattice design for baseline electron ringDemonstrate < 2 pm vertical emittanceCharacterize single bunch impedance-driven instabilitiesCharacterize electron cloud build-upDevelop electron cloud suppression techniquesDevelop modelling tools for electron cloud instabilitiesDetermine electron cloud instability thresholdsCharacterize ion effectsSpecify techniques for suppressing ion effectsDevelop a fast high-power pulser
11 very high priority R&D items to be addressed for the ILC technical design:
Targeted for CesrTAEffort with Low
Emittance e+ BeamTargeted for
ATF Effort
M. Palmer
2009 SLUO Meeting Sept 17, 2009 Page 31
Model of ILC final focus
Beamline, January 2008 May 2008
Summer 2007
HA PS
FD integration
ATF2 goals :(A) Small beam size ~37nm(B) nm stability of beam center
ATF international collaboration: MOU signed by 20 institutions ATF2 constructed as ILC model, with in-kind contributions Start of beam commissioning: October 2008
ATF2
A. Seryi
2009 SLUO Meeting Sept 17, 2009 Page 32
ILC – CLIC collaboration
CLIC ILC
Physics & Detectors L.Linssen, D.Schlatter F.Richard, S.Yamada
Beam Delivery System (BDS) & Machine Detector Interface (MDI)
D.Schulte, R.Tomas GarciaE.Tsesmelis
B.Parker, A.Seriy
Civil Engineering &Conventional Facilities
C.Hauviller, J.Osborne. J.Osborne,V.Kuchler
Positron Generation (new) L.Rinolfi J.Clarke
Damping Rings (new) Y.Papaphilipou M.Palmer
Beam Dynamics D.Schulte A.Latina, K.Kubo, N.Walker
Cost & Schedule P.Lebrun, K.Foraz, G.Riddone
J.Carwardine, P.Garbincius, T.Shidara
2009 SLUO Meeting Sept 17, 2009 Page 33
GDE: ILC Timeline
Reference Design Report (RDR)GDE process
TDP 2
LHC physics
2005 2006 2007 2008 20122009 2010 2011 2013
Ready for Project Submission
Tech. Design Phase (TDP) 1
We are hereB. Barish
April 2009
2009 SLUO Meeting Sept 17, 2009 Page 34
Tentative long-term CLIC scenarioShortest, Success Oriented, Technically Limited Schedule
Technology evaluation and Physics assessment based on LHC results for a possible decision on Linear Collider with staged construction
starting with the lowest energy required by Physics
First Beam?
TechnicalDesignReport(TDR)
ConceptualDesignReport(CDR)
Project approval ?
2007 2008 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
R&D on Feasibility Issues
Conceptual Design
R&D on Performance and Cost issues
Technical design
Engineering Optimisation&Industrialisation
Construction (in stages)Construction Detector
2009
G. Geshonke
2009 SLUO Meeting Sept 17, 2009 Page 35
Summary
ILC: 500 GeV, upgradable to 1 TeV
Technology quite advanced. Much recent progress.
TDP plan to be ready for a proposal in 2013.
Key R&D: Cavity gradient, improved RF sources, electron cloud, BDS
CLIC: designed to reach 3 TeV, probably in stages
Still much R&D. CTF3 just coming on line.
TDR expected end 2015. Could be proposed in 2018?
Key R&D: Structure gradient & damping, PETS, drive beam generation, also sources, damping rings and BDS issues