| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Steve Horne |
| Physics operator(s): | Unknown |
| Engineering operator(s): | Vinny Bertolino |
| Engineering Operator Run Comment |
| horne/granetz start up |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:36:55:130PM |
| Author: To Be Determined |
| Physics Operator's summary for run 951031 MP #120 Re-start C-Mod SL: S. Horne PO: R. Granetz EO: V. Bertolino Today's run plan: continue (and hopefully finish) MP #120, Re-starting C-Mod a the long shutdown. During the last run on Friday, there were two plasmas, both going vertically unstable early on, due to problems with hybrid control of EFC. This was traced to a hybrid/pcs software problem, which Steve Horne has fixed over the weekend. Problems with EF4 were also worked on. Summary: By the end of the day, we had 3 decent plasmas in a row (Ip=0.55-0.60 MA, shot length=1.3 s). These last 3 plasmas used a short pulse on the A-side valve to ready the machine for breakdown, rather than having it pre-filled with gas for several minutes. This mode of operation will be necessary when using boronization in the near future. There were lots of problems with camac early on, and with EFC (which was connected up backwards to the bus), but the real problem was with EF4, which never operated properly at all today. Scorecard: 7 plasmas 5 fizzles 4 duds (all due to power supply problems) 4 tests ---------- 20 total Run setup: Start with 951027010. Pre-fill is at 1.8e-5 torr. Discharge clean as usual in deuterium before the run Fill A-side plenum with 19-20 psi of deuterium Detailed shot log: Shot 01 -- Engineering test Shot 02 -- Engineering test of EF4. Lots of SCSI camac errors Shot 03 -- Another EF4 test shot, to verify camac operation. Everything worked fine. Next shot: try for plasma Shot 04 -- Plasma. Disrupted at 0.43 s, probably due to problems with EF4. Also there was no EFC current. The plasma was also very resistive (no surprise). Next shot: lower density demand to 0.8e20 m-2 and repeat. Shot 05 -- Fizzle. No current on EFC again. Next shot: reduce pre-fill to 1.5e-5. Shot 06 -- Plasma. Disrupted at 0.46 s. EFC is sick. This shot looks very similar to shot 04. EFC is apparently hooked up to the bus in the reversed configuration from the last run campaign. Next shot: switch EFC bus connections so its polarity is back to what it was last run campaign. Repeat shot. Shot 07 -- Fizzle. EFC worked well. EF4 still has some single-phasing problem Next shot: repeat Shot 08 -- Fizzle. Next shot: lower pre-fill to 1.3e-5 torr. Shot 09 -- Plasma. Ip=0.55 MA, terminated at 0.57 s. Becomes very disruptive at 0.42 s. EF4 single-phased again. Next shot: decrease density to nl04=0.6e20 m-2. Shot 10 -- Fizzle. Next shot: let hybrid takeover control of EF4 voltage, rather than EF4 current. This is to try and invert it more gently than the PLC does. Turn off gain on IC_EF4 after 0.1 s, and program EF4 voltage to 300 V until t=1 s. Shot 11 -- Dud. Early breaker fault prevented OH1, OH2's, and EF1's from turning on. Next shot: try again, no changes Shot 12 -- Plasma. Ip=0.51 MA, duration=0.55 s. Similar to shot 09. SCR blew in EF4. Maybe that was actually the problem all along. Next shot: reload shot 10, which was before control of EF4 was changed. Shot 13 -- Dud. OH2's crowbarred early, and pulled the PF breaker. Next shot: program in a gas puff at -0.50 s and turn off the pre-fill. This is the first attempt at getting a plasma without having the vacuum chamber pre-filled with deuterium for several minutes prior to the shot. This type of operation will be necessary when we start boronizing later in this campaign. Shot 14 -- Test of initial gas puff only. No power supplies enabled. Gas puff looks okay. Next shot: attempt plasma with pulse gas startup. Shot 15 -- Dud due to PF breaker pulling out again. Also no EF4 at all. Next shot: make a few minor modifications to the pre-plasma pulse gas programming, and try again. Shot 16 -- Dud due to power supply problems again. Next shot: more tweaking of the pre-plasma pulse gas programming. Shot 17 -- Fizzle, which is good news, since we used the pulse gas programming rather than the pre-fill for filling the machine. Next shot: Shorten the pre-plasma pulse gas spike width and try for plasma again. Shot 18 -- Plasma. Good shot. Ip=0.55 MA, duration=1.31 s. This was done with pulsed gas, rather than pre-fill. Plasma was diverted early on, but then became limited on the outboard limiter. Inner clearance was 2.5 cm. There are still problems with EF4. Next shot: Move RCUR in by 1.0 cm and reduce CLEARIN by 0.5 cm. Shot 19 -- Plasma. Good shot. Very similar to the preceding shot. RCUR did move in by 1.0 cm, and CLEARIN is now 2.0 cm. The plasma was diverted, but just barely. The x-point was very high. Problems with EF4 are still giving us lots of trouble with RCUR control. Next shot: Repeat with no changes Shot 20 -- Plasma. Another good shot, lasting until 1.32 s, when there's another upward disruption (no significant halo current). The plasma current looks much nicer, with Ip=0.58 MA. There were some hard x-rays. Due to continuing problems with EF4, which limits our ability to control the plasma position, et al, we are ending this run now so that our engineers can begin fixing the supply. |
| Session Leader Comments |
| Physics Operator Comments | |||
| Oct 31 1995 08:42:44:750AM | 951031001 | Robert Granetz | Today's run: continue (and hopefully finish) MP #120, Re-starting C-Mod after
the long shutdown. During the last run on Friday, there were two plasmas, both going vertically unstable early on, due to problems with hybrid control of EFC. This was traced to a hybrid/pcs software problem, which Steve Horne has fixed over the weekend. Problems with EF4 were also worked on. Start with 951027010. Pre-fill is at 1.8e-5 torr. |
| Oct 31 1995 09:37:57:220AM | 951031001 | Robert Granetz | Shot 01 -- Engineering test
|
| Oct 31 1995 09:38:09:670AM | 951031002 | Robert Granetz | Shot 02 -- Engineering test of EF4. Lots of SCSI camac errors
|
| Oct 31 1995 09:44:37:220AM | 951031003 | Robert Granetz | Shot 03 -- Another EF4 test shot, to verify camac operation. Everything
worked fine. Next shot: try for plasma |
| Oct 31 1995 09:58:42:480AM | 951031004 | Robert Granetz | Shot 04 -- Plasma. Disrupted at 0.43 s, probably due to problems with
EF4. Also there was no EFC current. |
| Oct 31 1995 10:19:28:310AM | 951031005 | Robert Granetz | Shot 05 -- Fizzle. No current on EFC again.
Next shot: reduce pre-fill to 1.5e-5. |
| Oct 31 1995 11:31:48:920AM | 951031006 | Robert Granetz | Shot 06 -- Plasma. Disrupted at 0.46 s. EFC is sick. This shot looks
very similar to shot 04. EFC is apparently hooked up to the bus in the reversed configuration from the last run campaign. Next shot: switch EFC bus connections so its polarity is back to what it was last run campaign. Repeat shot. |
| Oct 31 1995 11:41:25:720AM | 951031007 | Robert Granetz | Shot 07 -- Fizzle. EFC worked well. EF4 still has some single-phasing problem
Next shot: repeat |
| Oct 31 1995 11:55:17:900AM | 951031008 | Robert Granetz | Shot 08 -- Fizzle.
Next shot: lower pre-fill to 1.3e-5 torr. |
| Oct 31 1995 12:09:36:540PM | 951031009 | Robert Granetz | Shot 09 -- Plasma. Ip=0.55 MA, terminated at 0.57 s. Becomes very
disruptive at 0.42 s. EF4 single-phased again. Next shot: decrease density to nl04=0.6e20 m-2. |
| Oct 31 1995 12:23:04:120PM | 951031010 | Robert Granetz | Shot 10 -- Fizzle.
Next shot: let hybrid takeover control of EF4 voltage, rather than EF4 current. This is to try and invert it more gently than the PLC does. Turn off gain on IC_EF4 after 0.1 s, and program EF4 voltage to 300 V until t=1 s. |
| Oct 31 1995 12:33:55:800PM | 951031011 | Robert Granetz | Shot 11 -- Dud. Early breaker fault prevented OH1, OH2's, and EF1's from
turning on. Next shot: try again, no changes |
| Oct 31 1995 01:11:17:110PM | 951031012 | Robert Granetz | Shot 12 -- Plasma. Ip=0.51 MA, duration=0.55 s. Similar to shot 09.
SCR blew in EF4. Maybe that was actually the problem all along. Next shot: reload shot 10, which was before control of EF4 was changed. |
| Oct 31 1995 01:24:00:940PM | 951031013 | Robert Granetz | Shot 13 -- Dud. OH2's crowbarred early, and pulled the PF breaker.
Next shot: program in a gas puff at -0.50 s and turn off the pre-fill. This is the first attempt at getting a plasma without having the vacuum chamber pre-filled with deuterium for several minutes prior to the shot. This type of operation will be necessary when we start boronizing later in this campaign. |
| Oct 31 1995 01:34:16:280PM | 951031014 | Robert Granetz | Shot 14 -- Test of initial gas puff only. No power supplies enabled.
Gas puff looks okay. Next shot: attempt plasma with pulse gas startup. |
| Oct 31 1995 01:47:57:490PM | 951031015 | Robert Granetz | Shot 15 -- Dud due to PF breaker pulling out again. Also no EF4 at all.
Next shot: make a few minor modifications to the pre-plasma pulse gas programming, and try again. |
| Oct 31 1995 02:26:58:830PM | 951031016 | Robert Granetz | Shot 16 -- Dud due to power supply problems again.
Next shot: more tweaking of the pre-plasma pulse gas programming. |
| Oct 31 1995 02:43:14:270PM | 951031017 | Robert Granetz | Shot 17 -- Fizzle, which is good news, since we used the pulse gas programming
rather than the pre-fill for filling the machine. Next shot: Shorten the pre-plasma pulse gas spike width and try for plasma again. |
| Oct 31 1995 03:27:01:880PM | 951031018 | Robert Granetz | Shot 18 -- Plasma. Good shot. Ip=0.55 MA, duration=1.31 s. This was done
with pulsed gas, rather than pre-fill. Plasma was diverted early on, but then became limited on the outboard limiter. Inner clearance was 2.5 cm. Next shot: Move RCUR in by 1.0 cm and reduce CLEARIN by 0.5 cm. |
| Oct 31 1995 03:46:08:350PM | 951031019 | Robert Granetz | Shot 19 -- Plasma. Good shot. Very similar to the preceding shot. RCUR did
move in by 1.0 cm, and CLEARIN is now 2.0 cm. The plasma was diverted, but just barely. The x-point was very high. Problems with EF4 are still giving us lots of trouble with RCUR control. Next shot: Repeat with no changes |
| Oct 31 1995 04:17:31:900PM | 951031020 | Robert Granetz | Shot 20 -- Plasma. Another good shot, lasting until 1.32 s, when there's
another upward disruption (no significant halo current). The plasma current looks much nicer, with Ip=0.58 MA. There were some hard x-rays. |
| Oct 31 1995 04:17:45:570PM | 951031020 | Robert Granetz | Due to continuing problems with EF4, which limits our ability to control
the plasma position, et al, we are ending this run now so that our engineers can begin fixing the supply. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:23:21:980AM | Test | Ok | test |
| 2 | 09:22:52:560AM | Test | Ok | |
| 3 | 09:40:25:240AM | Test | Ok | |
| 4 | 09:50:09:980AM | Plasma | Ok | |
| 5 | 10:15:32:440AM | Plasma | Ok | |
| 6 | 11:03:26:110AM | Plasma | Ok | |
| 7 | 11:34:37:000AM | Plasma | Ok | |
| 8 | 11:46:09:710AM | Plasma | Ok | |
| 9 | 11:58:10:740AM | Plasma | Ok | |
| 10 | 12:11:15:710PM | Plasma | Ok | |
| 11 | 12:29:18:940PM | Plasma | Bad | ef4 shoot through |
| 12 | 12:58:00:820PM | Plasma | Ok | |
| 13 | 01:10:50:000PM | Plasma | Bad | oh2 faults |
| 14 | 01:26:19:670PM | Test | Ok | |
| 15 | 01:34:41:110PM | Plasma | Bad | oh2l fault |
| 16 | 02:14:07:160PM | Plasma | Bad | ef4 fault |
| 17 | 02:36:20:910PM | Plasma | Ok | |
| 18 | 03:08:19:950PM | Plasma | Ok | |
| 19 | 03:27:20:900PM | Plasma | Ok | |
| 20 | 03:45:53:680PM | Plasma | Ok | |
| 21 | 04:24:40:180PM | Test | Ok | |
| 22 | 04:50:49:920PM | Test | Ok | |