ILC RD at KEK Beam Control Technology ATF

ILC R&D at KEK • Beam Control Technology – ATF 2 ATF bldg • Acceleration Technology – High-gradient Cavities L-band R&D Stand – Linac System STF – Construction of Infrastructure STF Building

ATF Accelerator Test Facility • Construction started in 1993 • Originally as Damping Ring for warm collider • Achieved world smallest emittance ~2 pm • Still usefull for ILC (the only ring that can provide required emittance) • World-wide collaboration going-on

ATF Collaboration Board) • World smallest emittance achieved • Internationalization GLC ILC • TB mtg every May and Dec. assist rt consult TB (Technical KEK Directorate appoint rep ort Coordinators Work Groups SLAC, LBNL, FNAL, Cornell U, CERN, DESY, Orsay, INFN, several univs in London, IHEP, PAL, Japanese univs (Waseda, Nagoya, Tokyo, Hiroshima, etc) report Spokesperson (+ 3 deputies) assist consult Board) rt • Experiment program selected by TB (technical board) repo • Mo. U with ~20 institutes nominate coordinate CB (Collaboration report • 1993 construction started as Damping Ring for warm collider

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 (ATF 2, 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. Pulsed Laser Wire Consistency test from 3 cavity BPMs resolution ~17 nm Polarized positron production Beam image from XSR (sy=6. 4 mm) 3 -bunch extraction

Development of Fast Kicker (highlight of 2005) • ILC requires fast kickers with rise (fall) time of a few nsec (Otherwise Damping Ring would be too large) • Demonstrated in 2005 that ~3 ns is feasible (excited an oscillation of stored beam) • Try extraction from ATF in 2006 by series of kickers Measured kick angle Extraction scheme from DR in ILC

ATF 2 • Extend ATF extraction line Add Final Focus – Small beam size（～ 35 nm） • Focus the ATF beam to ~35 nm by ILC final focus optics • long-term maintenance – Beam center • Stabilization of the beam center to ~2 nm • 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. ~40 MV/m, operation < ~ 35 MV/m) LL (Low Loss)-type under R&D – Reached 51 MV/m with singlecell cavities • 9 -cell cavities under study • ~29 MV/m yet • to be installed in STF Phase 1

Cryogenic compressor Control Room Klystron Gallery Infra-structure for SC-RF production Cryogenic liquefier underground space for Linac phase 1 & 2 For EP, Clean Room

Valve Box STF Phase 1 First test at KEK of assembling all components 2 cryomodules (connected each other) each containing 4 cavities of TESLA-type and LL-type Weld connection 35 MV/m TESLA-type cavities Construction 2005 -2006 Operation 2007 45 MV/m Low-loss cavities

STF Phase 2 (2007 -9) • Plan: construct 1 RF unit of ILC 1 bouncer-type modulator, 1 multi-beam 10 MW 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-structure Clean room : New clean room completed in Mar. 2006 EP: 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 room. EP bed of ILC Clean room for 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 ATF 2 • • 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 (France, CERN)

R&D Items at STF • MBK (multi-beam klystron) development • Baseline cavity fabrication with new coupler and tuner • Development of LL (Low Loss) single-cell cavity • Development of LL (Low Loss) 9 -cell cavity with new coupler and tuner • Fabrication of Nb/Cu-clad seamless cavity • Photocathode system development