常伝導技術での lc の可能性 lc feasibility consideration with normal conducting technology...
TRANSCRIPT
常伝導技術での LC の可能性LC feasibility consideration
with normal conducting technology
第5回「機構の研究推進について」の意見交換会(ILC の推進について )
平成 24 年 2 月 13 日加速器・肥後寿泰
Why normal conducting for LC now?• Normal conducting (NC) X-band high gradient
research has been pursued for the past twenty years at SLAC, KEK and now at CERN.
• It is worthwhile to continue this research in order to merge the present NC technology with that currently being developed for a future CLIC-type machine.
• If a low energy machine is needed, NC X-band technology may serve as a compact, extendable and versatile (e+e-/γγ) machine.
• For higher energies, it can serve as a prototype for a CLIC type machine.
2 肥後 機構の意見交換会( 2 月 13 日)
Physics playground
肥後 機構の意見交換会( 2 月 13 日) 3
Stage 1: e+ e- Z, WW, HZ @ Eee ~ 90 – 250 GeV
Stage 2: e+ e- t t e- e- γγ H, HH
@ Eee ~ 170 – 350 GeVStage 3: e+ e- H H Z, t t H
@ Eee ~ 500 GeVR. Belusevic, KEK Preprint 2008-33
Accelerator layout
4 肥後 機構の意見交換会( 2 月 13 日)
GLC configuration 2004
Design: 500 GeV and extendable to 1TeV
5 肥後 機構の意見交換会( 2 月 13 日)
GLC Project, KEK Report 2003-7
GLC two tunnel schematic
SLED-II pulse compression 1.6microsec400nsec
Klystron peak power 75MW 60cm effective length
accelerator structure
6 肥後 機構の意見交換会( 2 月 13 日)
GLC Project, KEK Report 2003-7
GLC RF configuration
Loaded gradient 50 MV/m
75 MW, 400ns /
structure
4 klystrons / modulator
PPM klystron75MW, 1.6 microsec
29m SLED-II
7 肥後 機構の意見交換会( 2 月 13 日)
GLC Project, KEK Report 2003-7
Rough-rough design parameters (1)GLC CLIC500 CLIC Stage 1
Total CM energy (GeV) 500 500 3000 250
Loaded accelerator gradient (MV/m) 50 80 100 85
Effective gradient (MV/m) 44 70
Linac length (km) 14.5 3.6
Klystron peak power (MW) 75 40
Klystron pulse length (ms) 1.6 1.0
Pulse compression ratio 4 4
Power / structure 75 52
RF pulse length 400 250
Beam current 0.86 2.2 1.2 1.2
8 肥後 機構の意見交換会( 2 月 13 日)
Rough-rough design parameters (2)GLC CLIC500 CLIC Present
Number of particles in a bunch 10 10 0.75 0.68 0.37
Bunch spacing (ns) 1.4 0.5 0.5
Number of bunches / train 192 354 392
Bunch train length (ns) 267 177 196
……….
Wall plug power (MW) 233
Peak luminosity (1034) 2.5
Cost
9 肥後 機構の意見交換会( 2 月 13 日)
Rough-rough design parameters (3)GLC CLIC500 CLIC Present
Modulator
Klystron XL4/PPM
Pulse compression Cavity comp.
Power delivery Low loss WG
Acc. structure length (m) 0.6 0.25 0.25
Phase advance / cell 5p/6 5p/6 2p/3 2p/3
Structure filling time (ns) 120 50 67 67
Beam hole aperture 2a (mm) 0.21-0.15 <0.145> <0.11> <0.11>
Vg/c (%) 5.1 – 1.1 1.9 – 1.1 1.7 – 0.8 1.7 – 0.8
………….
10 肥後 機構の意見交換会( 2 月 13 日)
1m RF unit configuration
肥後 機構の意見交換会( 2 月 13 日) 11
40MW X 1.0 ms X 2kly
250MW X 250 nsec
52MW / structure
Compressor cavity
Klystron feasibility
12 肥後 機構の意見交換会( 2 月 13 日)
0
20
40
60
80
100
120
0 200 400 600 800 1000 1200 1400 1600
Pulse Shotening of PPM#4 KlystronPower [MW]
Pulse width [ns]
1/Tpulse
XL4 NLCTA
PPM Nextef
PPM Nextef
13
Fabrication – 6/7 of the above tests, with all best results achieved with KEK-coordinated machining of structures.Testing – 4/7 with best performance of all categories of structures in tests made in NEXTEF at KEK.High-gradient science – Extensive measurements of high-gradient rf instrumental in developing theory.
KEK’s Fundamental Contributions to 100 MV/m Accelerating Structures
肥後 機構の意見交換会( 2 月 13 日)
Oide, Steinar: KEK/Japan – CERN Collaboration on Linear Collider Studies, Dec. 2011
TD24
T24
Preliminary and at 240ns FLT pulse
CLIC req.
14 肥後 機構の意見交換会( 2 月 13 日)
Conclusion • Worthwhile to reconsider NC choice for low energy
Higgs physics.• High gradients imply compact accelerator complex.• First stage may be built within a KEK-size site.• Operation can serve as a rigorous test of CLIC design,
with exception of drive beam.• Energy extendable.• Physics potential increased using e+e-/γγ• Critical issues still to be discussed are
– Overall design– Proof of RF system configuration– Cost
肥後 機構の意見交換会( 2 月 13 日) 15