MHI#19 号機の１回目の EP2  Process log  Condition of EP2 & Rinsing process  Status of working  Monitor data during EP & Rinsing process Period : 2012/2/17~ 2/27 Process : EP2(20μm) under low current density, Improved 1 st Water Rinsing, & Flange using FM-20, Degreasing(FM-20, 2%) [5min], HPR x 2 [7 hours], Assembly in C.R., Vacuum evacuation, Leak check, ℃ (~48hours) Preparation : Washing vacuum components with ultrasonic, Cleaning in C.R. Workers : M. Sawabe, Kirk, T. Shishido (KEK), K. Nakamura, F. Tsukada, T. Kitajima (Assist Engineering Co.), T. Okada (K-VAC), M. Asano, T. Yanagimachi (Nihon Advanced Technology) Kirk STF Cavity Group 1

EP acid (2/24 のサンプルを使用 ) Nb ingredient : 10.2g/ℓ HF ingredient : ? g/ℓ ( 全体 ?g/ℓ の 65% が反応に使われる ) Al ingredient : <?mg/ℓ Current density : ～ 33mA/cm 2 ( 温度を低く抑えるため ) Cavity surface temperature : <35 ℃ ( 上流側 BP のみ霧吹き水冷 ) Control Voltage : 温度と電流密度を見ながら制御 With normal N 2 gas flow during extracting EP acid (8ℓ/min) 1 st water rinsing (1.5hours) Improved version (25ℓ/min で 20 分間上下から流し続ける ) 1 分毎に 1 秒間水抜きを繰り返す (40 分間 ) 最後の 30 分は 10min (storing)/3min (flushing) で行う Degreasing (5 min) FM-20(2%) HPR ( ～ 7 hours) 3h32m (4 turns, w/o blind flanges) 3h32m (4 turns, w/ blind flanges) Condition of EP2 & Rinsing & Flange using FM-20 & Flange using FM-20 2

Process log ① STF Cavity Group 2/1717:00MHI#19 is carried in EP area Check every flange Polishing every flange by scotch bright 2/20 9:15Check every flange flange 10:45Check every flange [O.K.] / Attachment of jigs for EP HPR operation starts without cavity 11:20Set cavity to EP bed with crane 11:25Meeting for tomorrow’s working procedure Installation of cathode bar to cavity [O.K.] Set data logger to cavity (totally 12ch) Leak check with N 2 gas [O.K.] Preparation for EP is completed 14:00fin. 3

STF Cavity Group 2/21 9:31Cavity rotation starts / EP acid flow starts 9:58EP2 starts / Area monitor around EP area 11:16EP2 stops [1h18m] / Idling rotation (3 rpm / 20min) / Plastic case detachment 11:37Idling rotation stops 11:38EP acid is removed from cavity with N 2 gas flow(0.020MPa) 11:50First rinsing with ultra pure water starts 13:20First rinsing with ultra pure water stops [1h30m] 13:30Detachment of restriction jigs / Data logger detached 13:40Un-installation of cathode bar from cavity / washing cathode bar (sulfur exists) Vacuum parts rinsing with ultrasonic in C.R. transferring cavity from EP bed to wagon Detachment of jigs for EP / Detaching every blind teflon flange (No mark) 14:20Brushing at every flange and HOM couplers using FM-20 / Shower rinsing Attachment of flanges for degreasing 14:45Flowing FM-20 into cavity 14:47Degreasing with ultrasonic starts 14:52Degreasing with ultrasonic stops [5min] 14:54Removing FM-20 from cavity Detachment of flanges for degreasing 15:00Brushing at every flange using FM-20 / Shower rinsing Process log ② 4

STF Cavity Group 2/2115:35Transferring cavity from wagon on turntable for HPR using crane 15:38Checking tolerance between position of nozzle and center of beam pipe 15:451 st HPR for inside cavity starts 19:131 st HPR for inside cavity stops [3h32m] (4 turns) 19:20Attaching every blank flange in C.R. 19:48fin. 2/22 9:08HPR outside cavity with blind flanges starts [45mins] 9:562 nd HPR for inside cavity with blind flanges starts 13:282 nd HPR for inside cavity with blind flanges stops [3h32m] (4 turns) 13:30Cavity enters into C.R. 13:55Assembly in C.R. (Class 10) starts 14:50Assembly in C.R. (Class 10) finishes / Moving out from Class10 to Class :56Vacuum evacuation starts with heat gun warming 15:02Turbo pump Turbo pump status 100% Metal gauge -2 Pa 15:30Leak check -3 Pa (Perfect!) [O.K.] ℃ starts (Max Vacuum Level just after baking start : ~2.17 x Pa) 16:18Cavity vacuum : 1.81 x ℃ /99.9 ℃ /109.3 ℃ /63.4 ℃ (Top/Cell#3/Cell#7/Bottom) 18:37Cavity vacuum : 4.13 x ℃ /140 ℃ /140 ℃ /125 ℃ (Top/Cell#3/Cell#7/Bottom) Process log ③ 5

Process log ④ STF Cavity Group 2/2412:00Cavity vacuum : 2.86 x ℃ /140 ℃ /140 ℃ /140 ℃ (Top/Cell#3/Cell#7/Bottom) 16:54Cavity vacuum : 2.78 x ℃ /140 ℃ /140 ℃ /140 ℃ (Top/Cell#3/Cell#7/Bottom) 17:10Baking Off Ion Pump ON 17:50Cavity vacuum : 5.68 x ℃ /103 ℃ /75 ℃ /68 ℃ (Top/Cell#3/Cell#7/Bottom) 2/2523:00Cavity vacuum : 5.29 x ℃ 2/2617:00Cavity vacuum : 4.75 x ℃ 2/27 9:00Cavity vacuum : 4.61 x Pa (0.0 x :25MHI#18 moves to V.T. stand ベーキング後の空洞真空の下がり具合は前回同様低い。 やはりベーキング温度が高いことが効いているようである。 6

STF Cavity Group Status of 1 st EP2 for MHI#19 ① current voltage T cavity T reservoir T room T cavity average current density 平均電流密度が 35mA/cm 2 程度になる ように電圧を調整する。 (low current density EP) 7

STF Cavity Group Status of 1 st EP2 for MHI#19 ② 左図は平均電流密度と電圧の相関 右図は定常状態での分布 target 8

最近の定常状態の比較 ※ MHI#12, 13, 16 号機の２回目の EP2 は 5μm しか行っていない。 Cavity Mean temp. [ ℃ ]R.M.S. temp. [ ℃ ] Mean i [mA/cm 2 ]R.M.S. i [mA/cm 2 ] MHI-A 1 st MHI#12 1 st MHI#13 1 st MHI#12 2 nd MHI#13 2 nd MHI#14 1 st MHI#15 1 st MHI#14 2 nd MHI#15 2 nd MHI#16 1 st MHI#16 2 nd MHI#17 1 st MHI#14 3 rd MHI#15 3 rd MHI#16 3 rd TOS#2 1 st MHI#18 1 st MHI#19 1 st

空洞内と外部温度との比較 STF Cavity Group Cavity 空洞内 上流 BP Cell#1Cell#2Cell#3Cell#4Cell#5Cell#6Cell#7Cell#8Cell#9 下流 BP 環境 MHI-A 1 st 26.1 MHI#12 1 st 25.6 MHI#13 1 st 26.9 MHI#12 2 nd 26.2 MHI#13 2 nd 26.6 MHI#14 1 st MHI#15 1 st MHI#14 2 nd MHI#15 2 nd MHI#16 1 st MHI#16 2 nd MHI#17 1 st MHI#14 3 rd MHI#15 3 rd MHI#16 3 rd TOS#2 1 st MHI#18 1 st MHI#19 1 st ※今回も前回同様、上流側ビームパイプに保冷材及び霧吹きを行ったため、温度が低く抑えられた。 10

Status of 1 st EP2 for MHI#19 ③ STF Cavity Group #1#2#3#4#5 #6#7#8#9#10 EP2 の間の空洞表面温度の状況。 #11 #12 Steady state: ℃ 11

STF Cavity Group Status of 1 st EP2 for MHI#19 ④ #1#2#3#4#5 #6#7#8#9#10 EP2 の間の空洞表面温度の状況（前ページの最後の拡大図）。 #11 #12 12

STF Cavity Group #1#2#3#4#5 #6#7#8#9#10#11 #12 Status of UWR for MHI#19 ① Steady state:

STF Cavity Group 一次洗浄中の空洞温度の状況（前ページの拡大図） #1#2#3#4#5 #6#7#8#9#10#11 #12 Status of UWR for MHI#19 ② 14

Status of UWR for MHI#19 ③ STF Cavity Group 15

STF Cavity Group Status of HPR for MHI#19 ノズルは 1st HPR では４往復、 2nd HPR でも４往復させた。 16