K Furukawa for injector linac Injector Linac Progress

入射器の現状 新規陽電子生成装置からの陽電子 K. Furukawa for injector linac Injector Linac Progress towards Super. KEKB K. Furukawa, KEK, Oct. 2014. 1

運転時間と故障率の推移 KEK 電子・陽電子入射器の運転時間と故障率の履歴 18000 8 7 年間運転時間 14000 総積算運転時間 12000 故障率 6 5 10000 4 8000 3 6000 4000 2 2000 1 KEKB TRISTAN 0 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 0 PF 故障率 [%] 総積算運転時間/10 [時間] 年間の運転時間 [時間] 16000 年度 Injector Linac Progress towards Super. KEKB 東日本大震災 K. Furukawa, KEK, Oct. 2014. 4

フラックスコンセントレータ試験時のケーブル焼損 u 昨年末ケーブルを 20 cm 焼損した Injector Linac Progress towards Super. KEKB K. Furukawa, KEK, Oct. 2014. 6

8 Super. KEKB 向け陽電子生成 bridge coils side view 10 n. C primary e- DC QM spoiler solenoid LAS Accel. structure target primary e- beam e+ beam hole positron 5 n. C injection e- production Target Flux Concentrator pulsed ST pulsed QM Flux Concentrator Bridge Coils 標的後の陽電子捕獲は、新規開発の フラックスコンセントレータ (FC) と、大口径 S-band 加速管 (LAS) 減速捕獲による Satellite bunch (Beam loss) 削減 標的脇 (3. 5 mm) の電子通過用ピンホール (2 mm) 標的保護用ビームスポイラ Injector Linac Progress towards Super. KEKB e+ beam K. Furukawa, KEK, Oct. 2014. 8

Flux Concentrator (FC) T. Kamitani u 外周の一次コイルにパルス電流を流 して導体内に誘導電流を発生させる と、磁束(flux)が開口部内に圧縮 (concentrate)され強いソレノイド磁 場ができる。 FC length outer diameter inner diameter (min. ) inner diameter (max. ) peak current pulse width parameters 100 mm 7 mm peak field inductance 3. 5 T 1. 0 m. H Injector Linac Progress towards Super. KEKB 52 mm 12 k. A 6 ms (half-sine) K. Furukawa, KEK, Oct. 2014.

10 T. Kamitani 陽電子生成標的 u 標的材料 タングステン 14 mm長 (= 4. 0 X 0) u タングステンと銅の胴体はHIP加 で接合 標的 ビーム通過孔 flux concentrator return yoke tungsten beam hole Injector Linac Progress towards Super. KEKB 標的内の熱分布 K. Furukawa, KEK, Oct. 2014.

T. Kamitani 標的破壊防止用 Beam spoiler n target上でのbeam spot sizeを sx , sy> 3 m distance 0. 7 mm に拡げてpeak energy密 screen & scatterer 度を下げ、破壊を防ぐ primary en スクリーン兼用 Al 2 O 3 板 injection hole (0. 14 mm thick) e- beam + Al 散乱板 (0. 25 mm thick) spot size [総物質量 = 0. 05 X 0] camera n spoiler上にも beam hole 有り Front Injector Linac Progress towards Super. KEKB target e+ hole Rear K. Furukawa, KEK, Oct. 2014.

陽電子捕獲部 (e+ capture section) SLED FC: FL_15_T BC: FC_15_T T. Kamitani KLY 1 -5 Solenoids: FC_15_11 LAS 10 MV/m [SLED off] 　　減速位相capture & 　　RF位相スリップ &加速位相に乗る KLY 1 -6 LAS加速管 Solenoids: FC_16_21 LAS 12 MV/m [SLED on] 加速位相 DC solenoid LAS : Large Aperture S-band 加速管 開口直径30 mm：通常の 1. 5倍 Injector Linac Progress towards Super. KEKB LAS 加速管 K. Furukawa, KEK, Oct. 2014.

新陽電子捕獲装置からの初めての陽電子観測 u Generated positron ~0. 1 n. C was transferred to the entrance of damping ring u With higher magnetic and electric field, 4 -n. C positron will be generated u Target shield (40 cm x 6 m long) Beam position will be finalized Horizontal u Alignment will be Vertical improved 3 mm 0. 1 mm Beam charge Injector Linac Progress towards Super. KEKB Largeconcentrator Flux aperture S-band structure beforefollowing solenoid/quad & quad installation 400 m ~0. 1 n. C Positron Primary Electron W target K. Furukawa, KEK, Oct. 2014. 17

(6) Acc-field grad. /phase at 1 -5 Injector Linac Progress towards Super. KEKB T. Kamitani K. Furukawa, KEK, Oct. 2014.

(6 -2) Acc-field grad. [MV/m] at 1 -5 T. Kamitani SLED を使用し、14 MV/m 程度まで 向上する予定 Injector Linac Progress towards Super. KEKB K. Furukawa, KEK, Oct. 2014.

光陰極 RF 電子銃 Cascaded frequency doublers Quasi traveling wave side couple cavity Yb fiber and Yb: YAG think disk laser Ir 5 Ce Cathode Ir 5 Ce photo cathode Injector Linac Progress towards Super. KEKB u 5. 6 n. C / bunch was confirmed u Next step: 50 -Hz beam generation & Radiation control K. Furukawa, KEK, Oct. 2014. 26

Instrumentation u. RF stability is crucial for the beam v. LLRF monitor is being developed v 60 high-power klystrons and 10 middle-power systems v 50 Hz synchronized data acquisition with event (beammode) recognition v 0. 1% amplitude and 0. 1 degree phase resolution u. BPM precision improvement v 100μm 50μm < 10μm v. Event recognition v. Mass production is underway u. Other beam monitors Injector Linac Progress towards Super. KEKB K. Furukawa, KEK, Oct. 2014. 29

Linac Schedule Overview RF-Gun e- beam commissioning at A, B-sector Qe- = 5 n. C e- commiss. at A, B, J, C, 1 Qe- = 5 n. C e+ commiss. at 1, 2 Qe+ = 0. 5 n. C (FC, DCS, Qe- 50%) e- commiss. at 1, 2, 3, 4, 5 Qe- = 5 n. C 1 n. C : Electron : Positron : Low current electron Injector Linac Progress towards Super. KEKB non damped e+ commiss. at 1, 2, 3, 4, 5 sectors e- commiss. at A→ 5 sectors 4 n. C 2 n. C damped e+ commiss. at 1→ 5 Qe+ = 1~4 n. C e- commiss. at A→ 5 Qe- = 1~5 n. C PF-AR ecommiss. K. Furukawa, KEK, Oct. 2014. 33

Linac Schedule Overview RF-Gun e- beam commissioning at A, B-sector Qe- = 5 n. C e- commiss. at A, B, J, C, 1 Qe- = 5 n. C e+ commiss. at 1, 2 Qe+ = 0. 5 n. C (FC, DCS, Qe- 50%) e- commiss. at 1, 2, 3, 4, 5 Qe- = 5 n. C 1 n. C : Electron : Positron : Low current electron Injector Linac Progress towards Super. KEKB non damped e+ commiss. at 1, 2, 3, 4, 5 sectors e- commiss. at A→ 5 sectors 4 n. C 2 n. C damped e+ commiss. at 1→ 5 Qe+ = 1~4 n. C e- commiss. at A→ 5 Qe- = 1~5 n. C PF-AR ecommiss. K. Furukawa, KEK, Oct. 2014. 35

Summary u. Steady progress towards first MR injection in 2015 u. Will finish earthquake disaster recovery in 2014 u. Will make staged improvements before 2017 u. Will balance between final beam quality and stable/staged operation u. Will select optimized route depending on available resources Injector Linac Progress towards Super. KEKB K. Furukawa, KEK, Oct. 2014. 36

Injector Linac Progress towards Super. KEKB K. Furukawa, KEK, Oct. 2014. 37

Emittance Preservation u. Offset injection may solve the issue u. Orbit have to be maintained precisely Mis-alignment leads to Emittance blow-up Orbit manipulation compensates it 100 samples Sugimoto et al. Injector Linac Progress towards Super. KEKB K. Furukawa, KEK, Oct. 2014. 38

Energy profiles and beam properties A B 1. 5 Ge. V e- C 10 n. C x 2 (for LER) 5 n. C x 2 (for HER) 0. 3 n. C x 1 (for AR) 0. 3 n. C x 1 (for PF) low emittance 1. 1 Ge. V RF gun 1 2 e+ target same energy DR 3 4 5 e-: Chicane 4. 219 Ge. V ee+ target l e-/e+ beams are delivered to 4 -rings with different current & energy. l Beam acceleration modes must be switched by 50 Hz pulse-by-pulse for top-up injection. Decelerate 1. 1 Ge. V e+ HER: 7 Ge. V e 5 n. C x 2 AR: 6. 5 Ge. V e 0. 3 n. C x 1 LER: 2. 5 Ge. V e+ 4 n. C x 2 PF: 2. 5 Ge. V e 0. 3 n. C x 1 1. 5 Ge. V C 1 2 3 4 5 Beam optics should satisfy the fast beam-mode switching. Injector Linac Progress towards Super. KEKB K. Furukawa, KEK, Oct. 2014. 39

Pulse-to-pulse modulation u Four PPM virtual accelerators for Super. KEKB project maybe with additional PPM VAs for stealth beam measurements based on Dual-tier controls with EPICS and event-system Event-based Control System Every 20 ms F. B e− Gun ARC PF Injection e– (2. 5 Ge. V, 0. 2 n. C) F. B e− Gun ARC Damping ring Super. KEKB-LER Injection F. B e– (3. 5 Ge. V, 10 n. C) F. B e+ Target e+ (4 Ge. V, 4 n. C) e− Gun ARC Super. KEKB-HER Injection F. B e– (7 Ge. V, 5 n. C) e− ARC F. B Gun PF-AR Injection F. B e– (6. 5 Ge. V, 5 n. C) Injector Linac Progress towards Super. KEKB K. Furukawa, KEK, Oct. 2014. 40