1. MHI#16 号機の２回目の EP2  Process log  Status of working  Monitor data during EP & Rinsing process  Comparison of EP2 Period : 2011/5/10 ~ 5/16 Process : CP @flanges, EP2(5μm) under low current density, Improved 1 st Water Rinsing, Brushing @HOM & Flange using FM-20, Degreasing(FM-20, 2%) [1hour], Brushing @Flange, HPR x 2 [10 hours], Assembly in C.R., Vacuum evacuation, Leak check, Baking @100 ℃ (48hours) Preparation : Washing vacuum components with ultrasonic, Cleaning in C.R. Workers : M. Sawabe, Kirk, M. Satoh (KEK), K. Nakamura, N. Tasaki, F. Tsukada (Assist Engineering Co.), T. Okada (K-VAC), M. Asano, S. Imada, T. Yanagimachi (Nihon Advanced Technology) Kirk 1 STF Cavity Group Meeting @2011/5/16

2. 2 EP acid (4/20 のサンプルを使用 ) Nb ingredient : 9.6g/ℓ HF ingredient : 25 g/ℓ ( 全体 34g/ℓ の 65% が反応に使われる ) Al ingredient : 18mg/ℓ Current density : ～ 37mA/cm 2 ( 最近の傾向より ) Cavity surface temperature : <35 ℃ 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 (1 hour) FM-20(2%) HPR ( ～ 10 hours) 5h17m (6 turns, w/o blind flanges) 4h23m (5 turns, w/ blind flanges) Condition of EP2 & Rinsing Brushing @HOM & Flange using FM-20 Brushing @Flange using FM-20 EP2 を 1 ～ 2 回行ったぐらいではたいして変化しない

3. Process log ① STF Cavity Group Meeting @2011/5/16 3 5/10 9:40Check every flange / Polishing input port by scotch bright 9:55~Attachment of jigs for EP 10:17HPR operation starts without cavity 10:44Set cavity to EP bed with crane 11:00Installation of cathode bar to cavity [O.K.] 11:04Meeting for tomorrow’s working procedure 11:12Set data logger to cavity (totally 12ch) 11:30Leak check with N 2 gas [O.K.] 12:00Lunch time 13:20HPR operation stops Preparation for EP is completed 14:00~Vacuum parts rinsing with ultrasonic in C.R. 15:30fin.

4. STF Cavity Group Meeting @2011/5/16 5/1110:10Cavity rotation starts / EP acid flow starts 10:30EP2 starts 10:47EP2 stops [17m00s] / Idling rotation (3 rpm / 20min) / Plastic case detachment 11:07Idling rotation stops 11:10EP acid is removed from cavity with N 2 gas flow(0.020MPa) 11:23First rinsing with ultra pure water starts 12:54First rinsing with ultra pure water stops [1h30m] 13:00Detachment of restriction jigs / Data logger detached 13:20Un-installation of cathode bar from cavity / washing cathode bar (No black mark) 13:28transferring cavity from EP bed to wagon / Checking inside cavity [O.K.] 13:50Detachment of jigs for EP / Detaching every blind teflon flange / Checking inside cavity (white mark is found at cell#9) 14:00Brushing at every flange and HOM couplers using FM-20 / Shower rinsing 14:10Checking inside cavity (white mark is found at cell#9) 14:13Attachment of flanges for degreasing 14:23Flowing FM-20 into cavity 14:27Degreasing with ultrasonic starts 15:27Degreasing with ultrasonic stops [1hour] 15:30Removing FM-20 from cavity 15:40Detachment of flanges for degreasing Checking inside cavity (white mark is found at cell#9) 15:45Brushing at every flange using FM-20 / Shower rinsing Process log ② 4

5. STF Cavity Group Meeting @2011/5/16 5/1116:00Transferring cavity from wagon on turntable for HPR using crane 16:05Checking tolerance between position of nozzle and center of beam pipe 16:191 st HPR for inside cavity starts 21:351 st HPR for inside cavity stops [5h17m] (6 turns) 21:40Attaching every blank flange in C.R. 22:09fin. 5/12 9:08HPR outside cavity with blind flanges starts [15mins] 9:242 nd HPR for inside cavity with blind flanges starts 13:472 nd HPR for inside cavity with blind flanges stops [4h23m] (5 turns) 13:55Cavity enters into C.R. 14:35Assembly in C.R. (Class 10) starts 16:20Assembly in C.R. (Class 10) finishes / Moving out from Class10 to Class1000 16:34Vacuum evacuation starts with heat guns 16:45Turbo pump status 100% 17:15Leak check thoroughly @~2.0x10 -3 Pa  Leak occurred at three ICF gaskets around bellows (Too low quality again!!!)  Re-tightening screws / stop the leak / Re-leak check  O.K. 17:45Baking @100 ℃ starts Max Vacuum Level just after baking start : ~1.20 x 10 -3 Pa 18:17Cavity vacuum : 1.08 x 10 -3 Pa @76 ℃ /81 ℃ /50 ℃ /60 ℃ /48 ℃ /53 ℃ /19 ℃ (Cell#3/Cell#7/Top/Bottom/Input/Probe/Room) 19:55Cavity vacuum : 3.78 x 10 -4 Pa @100 ℃ /104 ℃ /86 ℃ /85 ℃ /? ℃ /79 ℃ /19 ℃ (Cell#3/Cell#7/Top/Bottom/Input/Probe/Room) Process log ③ 5

6. Process log ④ STF Cavity Group Meeting @2011/5/16 6 5/1312:00Cavity vacuum : 3.31 x 10 -5 Pa @100 ℃ /105 ℃ /89 ℃ /100 ℃ /87 ℃ /90 ℃ /21 ℃ (Cell#3/Cell#7/Top/Bottom/Input/Probe/Room) 5/1417:25Cavity vacuum : 2.61 x 10 -5 Pa @100 ℃ /105 ℃ /88 ℃ /100 ℃ /86 ℃ /97 ℃ /22 ℃ (Cell#3/Cell#7/Top/Bottom/Input/Probe/Room) 17:30Baking Off 17:43Ion Pump ON 17:50Cavity vacuum : 2.20 x 10 -6 Pa @82 ℃ /86 ℃ /? ℃ /71 ℃ /78 ℃ /90 ℃ /22 ℃ (Cell#3/Cell#7/Top/Bottom/Input/Probe/Room) 5/16 8:50Cavity vacuum : 0.99 x 10 -7 Pa @22 ℃ (0.0 x 10 -8 Pa @I.P.) 9:30MHI#16 moves to V.T. stand

7. MHI#16 号機で見つかった白い模様 STF Cavity Group Meeting @2011/5/16 7 １回目の EP2 後 ２回目の EP2 後

8. 色々な空洞で見つかった白い模様 STF Cavity Group Meeting @2011/5/16 8 MHI#14 号機の１回目の EP2 後 MHI#15 号機の２回目の EP2 後 MHI#16 号機の２回目の EP2 後

9. 最近よく起こる ICF のリーク箇所 STF Cavity Group Meeting @2011/5/16 9

10. 今回の組み立て中に見つかった不良のヘリコフレックス STF Cavity Group Meeting @2011/5/16 10 スズメッキインジウムメッキ

11. STF Cavity Group Meeting @2011/5/16 Status of 2 nd EP2 for MHI#16 ① 11 current voltage T cavity T reservoir T room T cavity average current density 平均電流密度が 37mA/cm 2 程度になる ように電圧を調整する。 (low current density EP) voltage [V] average current density [mA/cm 2 ]

12. 12 STF Cavity Group Meeting @2011/5/16 Status of 2 nd EP2 for MHI#16 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

13. 最近の定常状態の比較 STF Cavity Group Meeting @2011/5/16 13 Cavity Mean temp. [ ℃ ]R.M.S. temp. [ ℃ ] Mean i [mA/cm 2 ]R.M.S. i [mA/cm 2 ] MHI-A 1 st 26.10.836.51.5 MHI#12 1 st 25.60.934.51.4 MHI#13 1 st 26.90.937.41.5 MHI#12 2 nd 26.20.536.31.4 MHI#13 2 nd 26.60.737.61.6 MHI#14 1 st 26.90.537.31.6 MHI#15 1 st 27.90.936.21.5 MHI#14 2 nd 29.00.838.01.2 MHI#15 2 nd 28.10.737.30.9 MHI#16 1 st 27.41.037.41.0 MHI#16 2 nd 29.20.236.00.7 今回は研磨量が 5μm と少ないためドリフトの影響が少ない。

14. Status of 2 nd EP2 for MHI#16 ③ STF Cavity Group Meeting @2011/5/16 14 #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: 34.0 29.0 31.4 29.1 30.6 28.1 25.4 31.1 29.7 28.7 28.9 11.3

15. STF Cavity Group Meeting @2011/5/16 Status of 2 nd EP2 for MHI#16 ④ 15 #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

16. STF Cavity Group Meeting @2011/5/16 16 #1#2#3#4#5 #6#7#8#9#10#11 #12 Status of UWR for MHI#16 ① 通信不良によるデータの跳びが最後になって急増した。 Steady state: 20.8 19.8 20.7 18.7 18.9 19.2 19.1 19.8 19.0 19.3 19.8 18.0

17. STF Cavity Group Meeting @2011/5/16 17 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#16 ②

18. Status of UWR for MHI#16 ③ STF Cavity Group Meeting @2011/5/16 18 ①は最初の注水完了時。 ②は流量を増やした状態での洗浄中。 ③は流量を戻した状態での洗浄中。 ① ② ③

19. STF Cavity Group Meeting @2011/5/16 Status of HPR for MHI#16 19 ノズルは 1st HPR では６往復、 2nd HPR では５往復させた。 ２回目は TOC 、 Particle 共に、最良の状態に戻っている。