ILC R&D at KEK• Beam Control Technology

– ATF– ATF2

• Acceleration Technology– High-gradient Cavities

L-band R&D Stand

– Linac System STF– Construction of Infrastructure

STF Building

ATF bldg

ATF Accelerator Test Facility

• Construction started in 1993

• Originally as Damping Ring for warm collider

• Achieved world smallest emittance ~2pm

• Still usefull for ILC (the only ring that can provide required emittance)

• World-wide collaboration going-on

ATF Collaboration

consult

CB (Collaboration

Board)

Spokesperson (+ 3 deputies)TB (Technical

Board)

KEK Directorate

Coordinators

Work Groups

assist report

repo

rt

report

report

report

appoint

nominate

assist

consult

coor

din

ate

•1993 construction started as Damping Ring for warm collider

•World smallest emittance achieved

•Internationalization GLC ILC

•MoU with ~20 institutes

•Experiment program selected by TB (technical board)

•TB mtg every May and Dec.

SLAC, LBNL, FNAL, Cornell U,

CERN, DESY, Orsay, INFN, several univs in London,

IHEP, PAL,

Japanese univs (Waseda, Nagoya, Tokyo, Hiroshima, etc)

ATF R&D Items• Beam tuning for low emittance• Beam dynamics studies (fast-ion, wiggler, etc)• Fast kicker development for ILC DR (next page)

• High resolution ring BPM• Cavity BPM developments

(ATF2, IP-BPM, ATF extraction line, etc)• Laser wire• Other beam diagnostics devices (XSR, ODR, etc)• S-band RF gun• CSR (coherent synchrotron radiation.)• Laser-Compton based polarized positron production• etc.

Consistency test from 3 cavity BPMs resolution ~17nm

Pulsed Laser Wire

Polarized positron production

Beam image from XSR(y=6.4m)

3-bunch extraction

Development of Fast Kicker (highlight of 2005)

0

20

40

60

80

100

0 5 10 15 20 25 30

Pulse timing v.s. kick angle(FID FPG-3000M)

KickAngle(urad)

Delay(ns) Time

•ILC requires fast kickers with rise (fall) time of a few nsec (Otherwise Damping Ring would be too large)

•Demonstrated in 2005 that ~3ns is feasible (excited an oscillation of stored beam)

•Try extraction from ATF in 2006 by series of kickers

Extraction scheme from DR in ILC

Measured kick angle

ATF2• Extend ATF extraction line Add Final Focus

– Small beam size （～ 35nm ）• Focus the ATF beam to ~35nm by ILC final focus optics• long-term maintenance

– Beam center • Stabilization of the beam center to ~2nm• Bunch-to-bunch feedback system by ILC-like beam

• Construction start 2005, Operation start Jan.2008• Construction by international collaboration

– Asia: fabrication of quads and BPM, etc– Americas: design, BPM electronics, magnet mover, power supply, etc– Europe: feedback, laser wire, final quad support, etc

Q-BPM from PAL

Qmagnet from IHEP

Development of High Gradient Cavities• Baseline: TESLA-type

• Gradient limited by surface magnetic field (max. ~40MV/m,

operation 35MV/m)

• LL (Low Loss)-type under R&D– Reached 51MV/m with single-

cell cavities

109

1010

1011

0 10 20 30 40 50 60

Qo

Eacc []MV/m]

Eacc,max = 51.4MV/m @ Qo = 0.777E10

~<

• 9-cell cavities under study

• ~29MV/m yet

• to be installed in STF Phase 1

Infra-structure for SC-RF production

Cryogenic compressor

Cryogenic liquefier

Control Room

Klystron Gallery

For EP, Clean Room

underground space for Linac phase 1 & 2

STF Phase 1

Weld connection

Valve Box

45MV/m Low-loss cavities

35MV/m TESLA-type cavities

First test at KEK of assembling all components

2 cryomodules (connected each other)

each containing 4 cavities of TESLA-type and LL-type

Construction 2005-2006

Operation 2007

STF Phase 2 (2007-9)• Plan: construct 1 RF unit of ILC

1 bouncer-type modulator, 1 multi-beam 10MW klystron 3 cryomodules each containing 8 cavities

• Cavity type: TESLA or LL (to be decided in 2007)• Design 2007 (during operation of phase 1)• Construction 2008-2009)

STF Infra-structureClean room : New clean room completed in Mar.2006EP: New EP(Electro Polishing) facility, start construction in 2006

•To be used for STF Phase 2 cryomodule production•and other SC cavities for other projects (KEKB, crab, ERL,...)

Chemical treatment roomEP bed of ILCClean roomfor cavity assembly

cryomodule assembly

carry hatch expansion clean room construction

R&D Items at ATF

• Emittance improvement of extracted beam (SLAC)

• Longitudinal feedback for stabilization of extracted beam (SLAC)

• Fast kicker (SLAC,LLNL)• Polarized electron source (Nagoya)• Polarized positron generation (Europe?)• Bunch-by-bunch feedback system (Oxford)• Laser wire (Kyoto, QMUL)• Cavity BPM (SLAC, Tohoku Gakuin)

R&D Items at ATF2

• Beamline design (SLAC)• Quadrupole magnets (IHEP, SLAC)• Q-BPM (PAL, SLAC)• IP-BPM• IP Beam size monitor• Stable/reliable power supply (SLAC)• Stabilization of final doublet quadrupole (F

rance, CERN)

R&D Items at STF

• MBK (multi-beam klystron) development• Baseline cavity fabrication with new couple

r and tuner• Development of LL (Low Loss) single-cell

cavity• Development of LL (Low Loss) 9-cell cavit

y with new coupler and tuner• Fabrication of Nb/Cu-clad seamless cavity• Photocathode system development