| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Martin Greenwald |
| Physics operator(s): | Steve Wolfe |
| Engineering operator(s): | Steve Fairfax |
| Engineering Operator Run Comment |
| Ohmic Confinement |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:09:477PM |
| Author: To Be Determined |
| Run of 931021 Greenwald, Wolfe Plan: Ohmic Confinement Run - Fill in data at moderate to high currents with density scan. Score card: 02 duds (1 no EF3) 00 Fizzles 26 Plasmas Summary: After a rocky (metallic actually) start, the major objective was essentially achieved. The early shots were plagued with disruptions and strong moly injections. Shot 010 was good at .855 MA. The following shot 011 was disruptive and ended with a tile across the TCI beam. After a 2.5 hour hiatus to remove this tile and inspect the machine, the run recommenced and was quite good though most shots disrupted at current turnover. Ip's scanned ranged from .5 to 1. MA at line average densities from 1 to 2.5 e20. Shots 10,12,14-28 all look suitable for confinement analysis. I'll pick out time slices and publish them.wr |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:36:50:520PM |
| Author: To Be Determined |
| Physics Operator Summary for 931021 Session Leader: Greenwald Physics Operator: Wolfe Engineering Operator: Fairfax Principal Miniproposal: 010 Ohmic Transport ************************************************************************** The plan was to fill in gaps in the deuterium confinement database for diverted plasmas. This was largely accomplished. A secondary goal was to produce a 1MA shot that ramped down in a controlled fashion. This was not accomplished. We started with the programming for 931019011, a 1MA shot, but with the OH1 and OH2 reverse current limits set to 20kA and 18kA, respectively. The first shots were short and very disruptive, typically termninating before 200msec. There were some early shots that reached a MA, but disrupted early. Going back to 931020027, an 850kA shot from yesterday, on shot 10 was successful, but 11 was another short disruptive mess. The reason for shot 11 (and possibly the earlier shots) being so bad became apparent after the shot. A tile (actually half a tile) was observed on the TCI window. On inspection, a second half-tile was found on the E-port bottom window, and a missing half-tile was spotted at E-port on the lower EF1 pocket. The tile on the TCI window was removed, and the run resumed after about a 2 1/2 hour delay. Shot 12 ran fine, a nice 750kA shot. There was still some problems with early minor disruptions, which were somewhat cured by lowering the early gas (70msec point) from 39V to 30V at shot#14. A current scan down to 500kA, with several densities being taken at each current, was carried out. The divertor gas puff in the private flux region was used for the density scan, with the A-side valve turned off as the divertor gas puff came in. At higher densities/gas puffs there was a problem holding the current flat. I was programming for about a 10% rise in current, but the gas influx caused a sag. I had some success combatting this by increasing the PID P gain to 10.0 and adding derivative gain D=2 from 0.5sec to 1.0 sec. I think it could stand more derivative gain. At the end of the run we went back to high current. Several good shots at 890kA were run, but returning to 1MA failed to substantially improve over previous efforts. Mo Injections led to disruptions in both 1MA cases tried at the end of the day (#27,28). #28 had numerous injections, and may be symptomatic of another tile in trouble. The next operator is warned to be on the lookout for flying tiles. The fill pressure started at 1.4e-5, was lowered to 1.3e-5, but put back to 1.4 after a dud on shot #13. Shots #4 and 14 were duds, suitable for diamagnetics baselines. Problems: --------- Two half tiles were observed to be lying on lower windows. One (H-port) was removed. This brings the total of known broken tiles to three, all apparently from the EF1 pockets. EF3 failed to fire on shot #4. Apparently a reset was not communicated to the supply. A dud resulted. On #18 and 19, the bus rogowski digitization was inadvertantly set to end before commutation. As a result, FFIT bombed out, and EFit ran with no FCOIL data. The EFIT output looks ok, but may not be reliable. Shot#20 was a repeat of 19, with the proper digitization restored. Scorecard: ---------- Duds 2 (1 caused by power supply failure) Short,disruptive 7 Good shots 19 ----------- -- Total 28 |
| Session Leader Comments | |||
| Oct 21 1993 09:04:38:210AM | Martin Greenwald | Ohmic confinement run in D2
First set up "trophy shot" at 1 MA try density scan then lower Ip and density scans at .5, .6, .7 MA | |
| Oct 21 1993 09:03:11:750AM | 931021001 | Martin Greenwald | Disrupts at .17 sec
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| Oct 21 1993 09:23:06:750AM | 931021002 | Martin Greenwald | Disrupts at .17 s
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| Oct 21 1993 09:41:29:090AM | 931021003 | Martin Greenwald | Reaches 1 MA but still disrupts at .64 s
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| Oct 21 1993 10:41:49:770AM | 931021003 | Martin Greenwald | Huge injection (moly?) at .42
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| Oct 21 1993 09:59:01:240AM | 931021004 | Martin Greenwald | Dud - no EF3
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| Oct 21 1993 10:35:44:090AM | 931021005 | Martin Greenwald | Disrupts at .26
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| Oct 21 1993 10:40:26:800AM | 931021006 | Martin Greenwald | Disrupts at .44, Ip = .9 MA
Huge injection (moly?) at .35 |
| Oct 21 1993 11:00:41:530AM | 931021007 | Martin Greenwald | Reaches 1 MA again but disrupts at .74
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| Oct 21 1993 11:15:38:080AM | 931021008 | Martin Greenwald | Disrupts at .2
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| Oct 21 1993 11:31:18:100AM | 931021009 | Martin Greenwald | Disrupts at .15
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| Oct 21 1993 11:48:46:480AM | 931021010 | Martin Greenwald | Drop back to shot 027 from 931020
Good shot Ip = .855 MA |
| Oct 21 1993 12:12:34:690PM | 931021010 | Robert Granetz | Good shot for fiducial purposes. Ip=-0.85 MA, duration=1.29 s.
No disruptions, although there is a large impurity injection at 0.78 s. Density is not too high either, nl4=0.7e19/m3. Btor=-5.2 T, pre-fill=1.3e-5 torr, D2. I think I might use this for the beginning of tomorrow's ohmic H-mode run. |
| Oct 21 1993 12:11:39:980PM | 931021011 | Martin Greenwald | Disrupts early - tile in TCI beam!!!
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| Oct 21 1993 03:09:08:010PM | 931021012 | Martin Greenwald | OK - with tile gone, good shot
Ip = .75 |
| Oct 21 1993 03:09:29:180PM | 931021013 | Martin Greenwald | Dud
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| Oct 21 1993 03:47:46:880PM | 931021014 | Martin Greenwald | Puff through the divertor
higher density nel = 2e20 by end disrupts at 1. sec |
| Oct 21 1993 03:48:46:440PM | 931021015 | Martin Greenwald | drop puff a bit
density plateaus at nel = 1.5e20 disrupts at 1.05 sec |
| Oct 21 1993 04:02:20:500PM | 931021016 | Martin Greenwald | drop puff about 30%
density plateaus at nel = 1.1e20 disrupts at 1.15 sec |
| Oct 21 1993 04:14:53:440PM | 931021017 | Martin Greenwald | drop current to .67 MA
nel= .95e20 |
| Oct 21 1993 05:09:58:400PM | 931021019 | Martin Greenwald | drop current to .67 MA
nel= .95e20 |
| Oct 21 1993 05:11:06:690PM | 931021020 | Martin Greenwald | drop current to .62MA
nel= 1.3e20 |
| Oct 21 1993 05:19:06:360PM | 931021021 | Martin Greenwald | drop current to .5MA
nel continues up to 1.6e20 then disrupts at .85 sec |
| Oct 21 1993 05:35:43:410PM | 931021022 | Martin Greenwald | puff turned town too far - nel only .6e20
Ip up too. .56MA |
| Oct 21 1993 05:43:16:420PM | 931021022 | Martin Greenwald | puff turned town too far - nel only .6e20
Ip up too. .56MA fringe jump on interferometer |
| Oct 21 1993 05:53:52:510PM | 931021023 | Martin Greenwald | Ip down to .52 MA
nel to .85 e20 |
| Oct 21 1993 06:10:08:620PM | 931021024 | Martin Greenwald | Ip up to .89
nl to .8e20 big moly injection at .7 |
| Oct 21 1993 06:21:48:170PM | 931021025 | Martin Greenwald | Disrupts at .74 sec immediately following a big moly injection
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| Oct 21 1993 06:29:06:070PM | 931021025 | Martin Greenwald | Disrupts at .74 sec immediately following a big moly injection
this injection and the one on the previous shot were from the scanning probe! It should be off from here on out. |
| Physics Operator Comments | |||
| Oct 21 1993 09:07:55:110AM | 931021001 | Steve Wolfe | MP#010
Session Leader [G] Physics Operator - wolfe Engineering Operator - Fairfax Plan: Fill in the blanks in the D confinement data Start from 931019011, Raise current limit on OH1 reverse to 20kA, and OH2 from 15kA to 18kA. Turn off A-side gas puff at 0.88 sec Fill = 1.4e-5 result: Short and disruptive- disrupted at .170 sec |
| Oct 21 1993 09:29:05:200AM | 931021002 | Steve Wolfe | Shot 2:
Lower gas at 76 msec by a couple of volts result: same thing For shot 3: Drop early gas again, to 40V Move limiter out from 93 to 94cm. |
| Oct 21 1993 09:44:01:290AM | 931021003 | Steve Golovato | Raised fill to 1.4e-5. Pretty shot, no disruption, 850ka, ran to 1.3s.
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| Oct 21 1993 09:44:33:600AM | 931021003 | Steve Golovato | Another beauty. Raising rf power each shot. Peak about 200kw this shot.
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| Oct 21 1993 09:44:51:420AM | 931021003 | Steve Golovato | Another beauty. Raising rf power each shot. Peak about 200kw this shot.
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| Oct 21 1993 09:45:07:500AM | 931021003 | Steve Golovato | Another beauty. Raising rf power each shot. Peak about 200kw this shot.
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| Oct 21 1993 09:47:47:460AM | 931021003 | Steve Wolfe | For shot 3:
Drop early gas again, to 40V Move limiter out from 93 to 94cm. result: Longer shot Disrupts at 650. Got to a MA, but not very happily. |
| Oct 21 1993 09:58:58:170AM | 931021004 | Steve Wolfe | For shot 4:
Drop the fill to 1.3e-5 Result: EF3 failed to fire. -- Dud. |
| Oct 21 1993 10:28:34:390AM | 931021005 | Steve Wolfe | For shot 5:
No change. Result: Another shorty!!? about 280 msec and disrupting all the way For shot 6: Load Pulse gas3 waveform from 931020027 (lower across the board.) |
| Oct 21 1993 10:53:03:330AM | 931021006 | Steve Wolfe | For shot 6:
Load Pulse gas3 waveform from 931020027 (lower across the board.) Result: About half a second. Big Mo injection at .36 |
| Oct 21 1993 11:10:19:510AM | 931021007 | Steve Wolfe | For shot 7:
No change Result: Better- Lasts to about 750 msec For shot 8 extend gas puff to 700msec |
| Oct 21 1993 11:33:15:250AM | 931021009 | Steve Wolfe | For 9:
Move early RCUR position to .68 (was .70) Move ZCUR at 200 msec to -2cm Result: Another short one! Punt for now - try reloading 931020027 for shot 10. |
| Oct 21 1993 11:50:53:280AM | 931021010 | Steve Wolfe | Punt for now - try reloading 931020027 for shot 10.
Result: This one ran nicely; still has a small problem at 0.1 to 0.15 sec, and a BIG Mo injection at 780, but it survives all the way down. |
| Oct 21 1993 12:03:17:830PM | 931021010 | Robert Granetz | Good shot for fiducial purposes. Ip=-0.85 MA, duration=1.29 s.
No disruptions, although there is a large impurity injection at 0.78 s. Density is not too high either, nl4=0.7e19/m3. Btor=-5.2 T, pre-fill=1.3e-5 torr, D2. |
| Oct 21 1993 12:07:52:910PM | 931021011 | Steve Wolfe | Start the current scan:
Try for 750kA and extend gas to 1sec. Result: Another short one. This time, a tile or something has appeared on the TCI window again! |
| Oct 21 1993 02:34:24:880PM | 931021011 | Steve Wolfe | On inspection , it was found that tiles were visible on the TCI window (H-bottom) and
on the CO2 scattering window at E bottom. A missing half-tile was observed on the lower EF1 pocket at E-port. The H-port tile fragment (half a tile, split like the last time) was removed and the window replaced. There is no gate valve at the E-port window, so that fragment was left in place. |
| Oct 21 1993 02:51:37:370PM | 931021012 | Steve Wolfe | Shot #12:
Retry of shot 11, hopefully with no Moly events. Looks like a good 750 - 770kA shot Still some early bursts, and some small injections late, but it runs to 1.3 sec Density reaches about 8e19 at .8 sec, then falls. |
| Oct 21 1993 03:13:05:260PM | 931021013 | Steve Wolfe | Shot #13:
Drop the gas puff from 39 to 30V at 70msec Turn A-side puff down from 400msec to 700msec Puff through private flux region (20psi) Result: A dud@! |
| Oct 21 1993 03:26:38:690PM | 931021014 | Steve Wolfe | Shot #14:
Raise the fill to 1.4e-5 and try again. Result: Got lots of gas! Disrupts at 1sec. Reaches 1.8e20 on NL_05 |
| Oct 21 1993 03:43:58:730PM | 931021015 | Steve Wolfe | Shot #14:
Turn A-side off at 400msec. Results: Lasted a little longer. Starts to fin at .900 and disrupts at 1.05 Two small injections at .35 and .45 Got NL_05 = 1.35e20 |
| Oct 21 1993 03:47:21:410PM | 931021015 | Steve Wolfe | Shot #15:
Turn A-side off at 400msec. Results: Lasted a little longer. Starts to fin at .900 and disrupts at 1.05 Two small injections at .35 and .45 Got NL_05 = 1.35e20 |
| Oct 21 1993 03:59:11:610PM | 931021016 | Steve Wolfe | Shot #16:
Raise IP proportional gain to 10 from 8. Divertor gas puff reduced to 15.2psi Results: Lasted longer: disrupts at 1.14 Moly burst at 350. Density reaches 1.e20 |
| Oct 21 1993 04:14:54:970PM | 931021017 | Steve Wolfe | Shot #17:
Lower Ip to 625kA : 650kA Turn A-side puff off at 300ms Divertor gas puff was supposed to be earlier by 100msec, same level, but didn't get it in intime. Results: Looks good. Got about 660kA. lasts till 1.05, density just under 1.e20. |
| Oct 21 1993 04:29:40:670PM | 931021017 | Steve Wolfe | Shot #18:
Lower Ip to 590kA : 620kA Turn on derivative gain on IP at .5sec, D=1.0 Divertor gas puff will be earlier this time. Results: 600 to 625 ka, still droops. Density at 9e19 |
| Oct 21 1993 04:51:02:860PM | 931021019 | Steve Wolfe | Shot #19:
Raise final Ip to 650kA derivative gain on IP at .5sec to 1.0sec, D=2.0 Divertor gas puff increased to 17.2psi Results: Disrupts at 1sec; density gets to 1.4e20 Current is pretty flat. On this shot and #18, the bus rog data was digitized only until -.17sec, causing FFIT to bomb out. EFIT runs, without the FC data, and looks OK. |
| Oct 21 1993 05:02:30:350PM | 931021020 | Steve Wolfe | Shot #19:
No changes; get the coil data this time? Results: Similar. Disrupts at 1.04 |
| Oct 21 1993 05:17:43:370PM | 931021021 | Steve Wolfe | Shot #19:
Shot #21 Reduce current to nominal 500kA (490:550 ramp) Divertor gas puff reduced to 15.7 psi Results: Disruption at 0.85 530kA Flameout occurs earlier, around 375msec Density gets to 1.4e20 before the disruption. |
| Oct 21 1993 05:34:33:020PM | 931021022 | Steve Wolfe | Shot #19:
Shot #22 Divertor gas puff reduced to 9.9 psi Results: Lasted till 1.2sec. got 560ka nl_05 = 5e19 |
| Oct 21 1993 05:50:48:690PM | 931021023 | Steve Wolfe | Shot #23
Reduce current by 30kA Divertor gas puff increased to 12.8 psi Results: Disrupts at 1sec + Current at 520kA nl_05 = 8e19 |
| Oct 21 1993 06:08:05:950PM | 931021024 | Steve Wolfe | Shot #24
Raise current to 850 : 890kA Same gas puff Results: Good current, disruption at 1.2sec Mo injection at .7 sec takes out a bite. nl_05 = 7.5e19 |
| Oct 21 1993 06:24:17:630PM | 931021025 | Steve Wolfe | Shot #25
Raise gas puff to 15.8psi Results: Disrupted at 0.76 sec following another big injection at almost the same time as last shot. nl_05 = 7.5e19 when the injection hits. |
| Oct 21 1993 06:30:09:510PM | 931021025 | Steve Wolfe | BLIP has been firing the FSP on the last few shots at .7sec
We suspect that's the cause of the injections and the disruption on #25 |
| Oct 21 1993 06:41:00:970PM | 931021026 | Steve Wolfe | Shot #26
Increase divertor gas puff to 18psi. Results: Good shot lasts till 1.2sec nl_05 = 1.e20 |
| Oct 21 1993 06:58:38:550PM | 931021027 | Steve Wolfe | Shot #27
Raise current to 1.:1.1 MA Results: Disrupted at 0.9sec 1.05MA, 1.e20 Xpoint is low (as programmed) |
| Oct 21 1993 07:09:56:820PM | 931021028 | Steve Wolfe | Shot #28
Raise x-point to nominal 0 point (-39.4cm) Raise divertor gas puff to 19.8psi Results: Shorter - lots of injections; disrupts at 0.76sec 1.02MA , NL_05 = 1.e20 |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:54:20:590AM | Plasma | Ok | Early disruption |
| 2 | 09:19:28:340AM | Plasma | Ok | Another early disruption |
| 3 | 09:36:09:210AM | Plasma | Ok | |
| 4 | 09:55:32:140AM | Plasma | Bad | EF3 did not fire; perhaps not reset in INIT? Not sure. No faults |
| 5 | 10:16:08:240AM | Plasma | Ok | Early disruption 400 kA |
| 6 | 10:35:05:000AM | Plasma | Ok | Early disruption |
| 7 | 10:52:28:680AM | Plasma | Ok | 1 MA disruption at 0.75 seconds |
| 8 | 11:11:23:180AM | Plasma | Ok | early disruption |
| 9 | 11:27:57:760AM | Plasma | Ok | Early disruption |
| 10 | 11:44:11:670AM | Plasma | Ok | Nice 850 kA shot |
| 11 | 12:01:28:150PM | Plasma | Ok | Tile on TCI window |
| 12 | 02:42:54:200PM | Plasma | Ok | Nice 775 kA shot |
| 13 | 03:06:43:850PM | Plasma | Ok | |
| 14 | 03:19:17:440PM | Plasma | Ok | high density, disrupted at 1 sec, 600 ka |
| 15 | 03:35:39:640PM | Plasma | Ok | another high-density discharge; disrupted at 500 kA |
| 16 | 03:52:00:340PM | Plasma | Ok | Good 780 kA shot |
| 17 | 04:07:27:860PM | Plasma | Ok | Good 650 kA shot |
| 18 | 04:22:43:440PM | Plasma | Ok | good 600 kA |
| 19 | 04:41:23:100PM | Plasma | Ok | 600 kA shot; 500 kA disruption |
| 20 | 04:57:09:740PM | Plasma | Ok | good 625 kA shot |
| 21 | 05:11:52:890PM | Plasma | Ok | 530 ka plasma, disrupted at 0.8 sec |
| 22 | 05:28:14:950PM | Plasma | Ok | good 570 kA shot |
| 23 | 05:43:14:620PM | Plasma | Ok | Good Plasma |
| 24 | 06:00:46:330PM | Plasma | Ok | Plasma Current 890 KA, good shot |
| 25 | 06:17:15:130PM | Plasma | Ok | 880 kA disruption at 0.7 sec |
| 26 | 06:32:56:850PM | Plasma | Ok | good 880 kA shot; disrupted at 450 kA 1.1 sec |
| 27 | 06:48:45:230PM | Plasma | Ok | 1.06 MA disruption; lots of sparks |
| 28 | 07:03:35:820PM | Plasma | Ok | 1.03 MA disruption |