| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Yuichi Takase |
| Physics operator(s): | Steve Horne |
| Engineering operator(s): | Frank Silva,Vinny Bertolino |
| Engineering Operator Run Comment |
| bertolino/silva plasma |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:08:290PM |
| Author: To Be Determined |
| Run 930805000 Session Leader -- Takase Physics -- Horne The intent of this run was to begin RF loading experiments. EFC cooling is broken so we couldn't run the chopper. Results: 1) This run had only 3 fizzles -- no duds, and began with a string of 21 good shots. I believe that the discharge cleaning and "bake" last night were responsible. (As well as reliable power supplies.) Here's Frank's description -- System baked overnight at 35 C., ECDC started at 05:00 with machine warm (no cooling). Imin set to 1700 A, Imax set to 3800 A. EFc lower cooling only. Coil and Wall temp set to 10 C. ecdc stopped at 07:30. full cooling started at 06:30. 2) The RF requirement was for a plasma at -2. cm with shape matched to the antenna. We began with last shot of run 930804 with some minor tweaks. By adjusting voltage programming in OH1 and OH2 and adding the EF2 to the Z_Cur controller, by shot 11 we had a well-controlled plasma. One key seems to be the OH1 current. When it goes to zero, the radial control changes, and typically the plasma moves out. This causes the OH2 current to decrease (OH2 is included in the radial position controller) and when it hits zero we loose vertical control and the shot dies. The time at which we loose radial control was advanced from 360 msec (shot 18) to 420 msec (shot 27) by a series of tweaks to oh1 and oh2 voltage programming. 3) Runs 930804 and 930805 show a much broader range of BZ vs IP for the first 30 msec, than earlier runs. It looks like the magic wall conditioning allows a faster current ramp. 4) The cause of the fizzles seems to be some noxious effect of opening the pellet injector's gate valve. Current opinion is that 1 - 2 10^(-6) of D2 comes in at -2 sec when the valve opens. One fix would be to weld it shut. Shot Gas Fill change nl Result 1 1.2e-5 1.5 Good 2 1.1 good 3 1.1 ef2 in z_cur good 4 1.1 +100 volt change in oh1 voltage GOOD 5 1.1 +200 V oh1 late puff on GAS 3 good more on GAS 2 6 more +v OH1 good late puff on 3 later (.4 sec) slightly less gas2 7 more OH2 current good (voltage prog) 8 1.1 z controller ef2 from 3e-3 -> 5e-3 more early gas oh2 v prog adjusted (glitch at .32?) good Unstable plasma -- elongation too high. 9 1.2 less early gas more negative oh2 V good less negative oh1 V RF at -.5 sec. good 10 more positive oh2 v Loose vertical control when oh2 L dies. good 11 oh2 v +10 .2 to .3 good Good control 0n R and Z 12 repeat good 13 move late puff on gas 3 later, shorter good 14 tweak oh1 V (+10v at .2) 15 extend r_cur pid past .5 sec good 16 Radial pos ramps in starting around .35 sec ramps in. Possibly ef4? Try tiny tweak to keep ef4 current up. good No obvious effect. 17 1.3 Adjust ef2 p gain and drawn I. 18 Tiny tweak to oh1 V -- + 2 v-sec or so. good r ramp starts at .362. 19 another +15v x .25 x 1/2 vs change good r ramp at .4 -- 20 try another tiny tweak +v in oh1. good 21 invert at .6 on pf good further tweak in oh1 v 10*.25*.5 v s bit of hard xrays 22 1.4 extend programming in time another 10*.25*.5 v s try pellet at .4 fizzle 23 1.1 pellet off. good got it back -- 24 pellet on at .4 another 10*.25*.5 v s fizzle 25 same fizzle 26 1.0 close pellet valve good It appears that the IGT ion gauge filament was damaged by the big gas puff from the pellet injector. This changed the calibration by nearly a factor of 2, which caused our fill pressure to be high by the same factor. 27 1.1 Long shot. good |
| Entered: Jul 7 2004 03:49:08:477PM |
| Author: To Be Determined |
| Physics summary of run 930805 This was day 1 of a three-day mini-proposal MP014 (ICRF Coupling). The goals for this run was to: 1) Produce a well-controlled (in R and z positions) reproducible plasmas with moderate elongation with good match to the rf limiter. 2) Try to tune to plasma load. The run was very productive, with 27 total shots. 24 shots were good plasmas (including mild runaway shots). 3 shots were fizzles, but it is believed that they are attributable to pellet injection valves (see Steve Horne's summary). Well-controlled reproducible plasmas were obtained by shot 11, which were used for both rf tuning and other piggy-back topics. Notably, the ECE vertical alignment MP018 was accomplished. See the logbook for other activities. The RF system had several control and data acquisition problems, but they have been solved and a reliable operating window was found by the end of the run. On shot 027, a 400msec pulse starting at -20msec and ending at +365msec was injected successfully into the plasma (and before plasma). The tuning is still not set for plasma loading. The power is set low (less than 1kW) to avoid high reflection faults. Firing RF after the plasma is gone was not successful because of high neutral pressure. Getting the right tuning for plasma load will be the major objective for tomorrow's run, with improved rf diagnostic data and improved tuning algorithm. If successful, we will switch over to deuterium gradually. |
| Physics Operator Summaries |
| Session Leader Comments | |||
| Aug 5 1993 08:59:34:380AM | Yuichi Takase | Today is day 1 of a 3-day miniproposal MP014 (ICRF Coupling).
We will start by establishing the plasma (moderately elongated, good match to the rf limiter) to couple into, and try to tune to the plasma loading. This will probably consume most of today's run. We will start with 930804029 plus some edits. Start with H, then if successful we will switch to D gradually (D/H concentration scan). Session Leader: Takase Physics Operator: Horne Eng. Operator: Silva/Bertolino | |
| Aug 5 1993 09:24:41:370AM | 930805001 | Yuichi Takase | Shot 001
Good shot for the first shot of the day. Need to fix the z position oscillation. |
| Aug 5 1993 09:38:43:320AM | 930805002 | Yuichi Takase | Shot 002
Higher current, disrupted at the end. |
| Aug 5 1993 09:56:42:050AM | 930805003 | Yuichi Takase | Shot 003
Good shot, a little higher density, dies after 0.4sec. |
| Aug 5 1993 10:20:50:070AM | 930805004 | Yuichi Takase | Shot 004
Good shot, a little lower density. Raise gas for the next shot. Changed OH1 on this shot, again for the next shot. |
| Aug 5 1993 10:31:38:550AM | 930805005 | Yuichi Takase | Shot 005
Good shot, good position control 260-320msec. |
| Aug 5 1993 10:46:07:080AM | 930805006 | Yuichi Takase | Shot 006
Better R position control, not as good on z. Lower current (trying to save OH for position control for longer time). |
| Aug 5 1993 11:08:57:140AM | 930805007 | Yuichi Takase | Shot 007
R_cur looks great, but oscillations on z_cur. Elongated too much? kappa around 1.6. |
| Aug 5 1993 11:42:16:470AM | 930805008 | Yuichi Takase | Shot 008
Big oscillations on z. Kappa still large. |
| Aug 5 1993 11:43:48:190AM | 930805009 | Yuichi Takase | Shot 009
Kappa much lower (<1.2). z_cur drifting down. |
| Aug 5 1993 11:59:12:120AM | 930805010 | Yuichi Takase | Shot 010
RF fired into vessel before commutation (-50msec). |
| Aug 5 1993 12:07:20:470PM | 930805011 | Yuichi Takase | Shot 011
First attempt to fire RF into plasma (250-300msec). Transmitter crowbarred before the shot. |
| Aug 5 1993 12:16:18:590PM | 930805011 | Yuichi Takase | Shot 011
Plasma position stable for 250-350msec (R and z). Kappa ramping up slightly 1.2-1.25. |
| Aug 5 1993 12:23:51:920PM | 930805012 | Yuichi Takase | Shot 012
RF fired but faulted on high reflection. The antenna is tuned now for vacuum loading, and not plasma loading. Need to find the right tuning for plasma load. |
| Aug 5 1993 12:40:37:360PM | 930805013 | Yuichi Takase | Shot 013
RF fired but faulted on high reflection. RF on for about 15msec starting at 264msec. Low power and almost all reflection. |
| Aug 5 1993 01:10:15:500PM | 930805014 | Yuichi Takase | Shot 014
No RF. Will be running nearly constant shots from now on. |
| Aug 5 1993 01:10:51:090PM | 930805015 | Yuichi Takase | Shot 015
No RF. |
| Aug 5 1993 01:21:13:830PM | 930805016 | Yuichi Takase | Shot 016
No RF. Transmitter crowbarred. |
| Aug 5 1993 01:27:05:170PM | 930805016 | Yuichi Takase | Shot 016
Nonthermal shot. Increase gas on the next shot. |
| Aug 5 1993 02:05:08:390PM | 930805017 | Yuichi Takase | Shot 017
Mo injection at 350msec. No RF (trying to fix transmitter crowbar problem). |
| Aug 5 1993 02:06:12:940PM | 930805018 | Yuichi Takase | Shot 018
Transmitter back on, but no RF. |
| Aug 5 1993 02:17:37:710PM | 930805019 | Yuichi Takase | Shot 019
Short RF pulse. Moved tuners for the next shot (guessing how much to move). Stub tuner at 333. Phase shifter at 454. |
| Aug 5 1993 02:37:46:030PM | 930805020 | Yuichi Takase | Shot 020
Short RF pulse, still faulting on high reflection. |
| Aug 5 1993 03:05:14:570PM | 930805022 | Yuichi Takase | Shot 021
No RF (wrong level on BiRa?) |
| Aug 5 1993 03:06:17:420PM | 930805022 | Yuichi Takase | Shot 022
First shot with pellet. First fizzle of the day. RF fired OK (but a lot of reflections). |
| Aug 5 1993 03:28:44:930PM | 930805023 | Yuichi Takase | Shot 023
Got plasma back. No pellet. RF fired. |
| Aug 5 1993 03:43:34:580PM | 930805024 | Yuichi Takase | Shot 024
Fizzle. Pellet enabled. RF fired multiple pulses starting from -20msec. |
| Aug 5 1993 04:13:41:130PM | 930805024 | Yuichi Takase | Back to vacuum tune.
|
| Aug 5 1993 04:32:11:740PM | 930805026 | Yuichi Takase | Shot 026
Got plasma back. RF still firing from -20msec to 380msec. Pellet gate valve closed. Set BiRa output to 0.6V for the next shot. |
| Aug 5 1993 05:10:59:710PM | 930805027 | Yuichi Takase | Shot 027
Good long RF pulse -20msec to 365msec. Data acquisition is taking a long time. This is the last shot of the day. |
| Physics Operator Comments |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:02:42:800AM | Plasma | Ok | 4.2KA on time |
| 2 | 09:21:57:870AM | Plasma | Ok | plasma |
| 3 | 09:39:38:420AM | Plasma | Ok | sparks |
| 4 | 09:58:05:560AM | Plasma | Ok | plasma |
| 5 | 10:15:37:620AM | Plasma | Ok | plasma |
| 6 | 10:36:11:820AM | Plasma | Ok | plasma |
| 7 | 10:52:36:060AM | Plasma | Ok | plasma |
| 8 | 11:14:59:120AM | Plasma | Ok | Good Shot |
| 9 | 11:31:57:120AM | Plasma | Ok | plasma |
| 10 | 11:47:43:620AM | Plasma | Ok | plasma/ |
| 11 | 12:00:55:600PM | Plasma | Ok | plasma |
| 12 | 12:14:50:370PM | Plasma | Ok | plasma |
| 13 | 12:28:56:040PM | Plasma | Ok | plasma/rf pulse |
| 14 | 12:47:50:650PM | Plasma | Ok | plasma |
| 15 | 01:03:48:560PM | Plasma | Ok | plasma |
| 16 | 01:18:14:270PM | Plasma | Ok | Good Shot |
| 17 | 01:38:33:880PM | Plasma | Ok | plasma |
| 18 | 01:51:59:830PM | Plasma | Ok | Good Shot |
| 19 | 02:06:21:680PM | Plasma | Ok | plasma |
| 20 | 02:21:29:040PM | Plasma | Ok | Good Shot |
| 21 | 02:35:14:760PM | Plasma | Ok | plasma invert on all increase 0.1 sec |
| 22 | 02:53:59:270PM | Plasma | Ok | fizzle |
| 23 | 03:07:33:230PM | Plasma | Ok | Good Shot |
| 24 | 03:26:13:840PM | Plasma | Ok | fizzle |
| 25 | 03:49:09:290PM | Plasma | Ok | fizzle |
| 26 | 04:15:05:220PM | Plasma | Ok | good shot |
| 27 | 04:41:23:670PM | Plasma | Ok | plasma |
| 28 | 05:31:46:360PM | Test | Ok | testing data system |
| 29 | 06:07:06:370PM | Test | Ok | worked again |
| 30 | 06:24:56:910PM | Test | Ok | worked again |