| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Brian Labombard |
| Physics operator(s): | Ian Hutchinson |
| Engineering operator(s): | Frank Silva |
| Engineering Operator Run Comment |
| MP245/MP242 Hutch/Silva |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:37:01:160PM |
| Author: To Be Determined |
| This run was to have been a study of neutral effects etc 248 and 242. However, we never got to a plasma. Ultimately the OH2U switch which was not opening and blew some fuses needed to be diagnosed in detail by engineering. We hope this can be done during the rest of the day but tomorrow's run is as yet uncertain till the switch problem is identified. |
| Session Leader Comments | |||
| May 18 1999 09:05:23:607AM | Brian Labombard | Plan for first half of tuesday's run: MP#245 "Dependence of Main Chamber Recycling on Plasma Density" Purpose: See if the regime of strong main chamber-wall recycling persists in very low core plasma density discharges. Plan: First try to run some very low density 0.8 MA ohmic discharges (NL04 < .2?!) and then do a density scan. Discharge cleaning: No ECDC. Base pressure is presently in the mid -9 range. The walls are degassed well enough now. Gas system setup: - Install ethylene bottle (for piggy-back plume studies) in position SG5. Target Plasmas: All plasmas will be 0.8 MA, 5.3 Tesla, diverted, ohmic shots (similar to 990429027) with optimized FSP target, and inner/outer gaps of 1.5 to 2 cm. Shot Sequence Plan: 1 Start from 990429027 with density programmed to NL04=0.6x10^20. Set up flappers to open at 0.9 seconds. 2-4 Turn gas down or off to obtain NL04 as low as we dare. Monitor hard x-rays, watch for twinkling pixels on the video cameras. 5-6 Repeat lowest density shot. Insert FSP and ASP scanning probes. Also do some pluming. 7-14 Begin upwards density scan. Do FSP/ASP and plumes. End with two shots at NL04~ 1.2 | |
| Physics Operator Comments | |||
| May 18 1999 08:36:13:500AM | Ian Hutchinson | Recyling Experiments. MP#245 "Dependence of Main Chamber Recycling on Plasma Density" MP#242 "Main chamber pressure dependence on right gap. LaBombard's Plan: Discharge cleaning: No ECDC. Base pressure is presently in the mid -9 range. The walls are degassed well enough now. Gas system setup: - Install ethylene bottle (for piggy-back plume studies) in position SG5. Target Plasmas: All plasmas will be 0.8 MA, 5.3 Tesla, diverted, ohmic shots (similar to with optimized FSP target, and inner/outer gaps of 1.5 to 2 cm. Shot Sequence Plan: 1 Start from 990429027 with density programmed to NL04=0.6x10^20. Set up flappers to open at 0.9 seconds. 2-4 Turn gas down or off to obtain NL04 as low as we dare. Monitor hard x-rays, watch for twinkling pixels on the video cameras. 5-6 Repeat lowest density shot. Insert FSP and ASP scanning probes. Also do some pluming. 7-14 Begin upwards density scan. Do FSP/ASP and plumes. End with two shots at NL04~ 1.2 Coldstart. Load 990429027. Lower nlo4 to 6.e20 | |
| May 18 1999 11:19:40:843AM | 990518010 | Ian Hutchinson | First plasma attempt. OH2 upper did not commutate. Bz is a bit negative, perhaps. |
| May 18 1999 11:22:25:153AM | 990518011 | Ian Hutchinson | Repeat. Same thing happens again. |
| May 18 1999 02:07:24:153PM | 990518011 | Ian Hutchinson | After examination of the switch some blown fuses are found. However there is no obvious reason the switches are not opening. Therefore after some further struggles the run is canned. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:09:30:780AM | Test | Bad | |
| 2 | 08:09:37:433AM | Test | Ok | (null) |
| 3 | 08:31:41:810AM | Test | Bad | |
| 4 | 09:42:38:390AM | Test | Ok | EF1 Upper test only okay |
| 5 | 09:53:47:123AM | Test | Ok | EF1 Lower test only Okay |
| 6 | 10:04:29:233AM | Test | Ok | OH coax test only Okay |
| 7 | 10:15:02:750AM | Test | Ok | TF test only 50kamps ,1 second okay |
| 8 | 10:34:35:890AM | Test | Ok | EFC chopper test only, 400v, 1.25kamps OK |
| 9 | 10:47:55:217AM | Test | Ok | EF4 Double swing test via hybrid |
| 10 | 11:02:21:450AM | Plasma | Bad | OH2 switch did not close |
| 11 | 11:20:23:420AM | Plasma | Bad | OH2 upper fault no commutation |
| 12 | 06:59:17:170PM | Test | Ok | OH2U Commutation Switch Test |
| 13 | 07:08:51:060PM | Test | Ok | OH2U Commutation Test |
| 14 | 07:18:16:887PM | Test | Ok | OH2U Commutation Test |
| 15 | 07:28:33:920PM | Test | Ok | OH2U Commutation Test |
| 16 | 07:37:47:140PM | Test | Ok | OH2U Commutaion Test |
| 17 | 07:47:22:187PM | Test | Ok | OH2L Commutation Test |