Alcator C-Mod Run 970516 Information

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Miniproposals
Miniproposal:170a
Date Filed: 5/13/1997
Title:Restart Operation: May 1997
First Author:Robert Granetz
Session Leader:Robert Granetz (shots 1-52)

Operators
Session leader(s):Robert Granetz
Physics operator(s):Ian Hutchinson
Engineering operator(s):Frank Silva,Vinny Bertolino

Engineering Operator Run Comment
Start Up Continued/Hutch/Bertolino,Silva

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Physics Operator Summaries
Entered: Jul 7 2004 04:36:57:020PM
Author: To Be Determined
Physop Summary 970516
Restart Operations.

PO Hutch SL Granetz
___________________

Experience today paralleled yesterday's.
Plasmas were obtained on 02, 23, 33.
Shot 33 was a reasonable shot terminated by vertical instability.

It is essential to lower clearin to about -1 in segment 2 if you
reload shot 33. Shot 52 is this reload including the corrections.

Teflon puffs were significant. This is a serious worry.

Numerous field tweaks were explored. Fairly reliable fizzles were obtained
at higher fill pressure, up to .025mtorr. (38ms puff).

From 33 on an exercise in lowering the Bz ramp rate was undertaken without
conspicuous success.

Numerous Camac errors were obtained in the second half of the run and so
some debugging was undertaken in real time to try to fix this. (Just
as well we did not have real plasmas!)

Problems include
1. Certainly the machine is dirty.
2. Teflon puffs may keep it that way.
3. There are, is some areas of magnetics space, unexplained duds and
breakdown time irreproducibilities. (However, I suspect that is a
function of trying to minimize pressure etc.)
4. Camac errors need to be diagnosed and overcome.


Session Leader Comments

Physics Operator Comments
May 16 1997 08:20:51:130AMIan HutchinsonReload shot 970515002. And do nothing.
Currents were (L,U)
EF1 -6194 -6143
EF2 -2160 -2200
EF3 120
EF4 -1373 -1391
OH1 -20550
OH2 -27517 -27754
May 16 1997 08:37:03:380AM970516001Ian Hutchinson1. Fiz. Got F_side fill pressure of 0.016. Breakdown at 8 ms.CII =.015. Z_m=0.1, Ha=0.2.
Imbalance in EF4 L=-1399, u=-1340. B_r=.004. Repeat.


May 16 1997 09:12:40:090AM970516002Ian HutchinsonPlasma. Got to time 0.33s. Goes vertically unstable.
Excessive elongation for this plasma. Too far in and too much clearin.
Fill pressure=.0135 mtorr. CII .008. Z_m=.1, Ha=.16.

Add control points to EF3 trace dusing first 20 ms.
May 16 1997 09:17:40:110AM970516003Ian Hutchinson3. Fiz
CII=.011, Z_m=.2, Ha=.15

Add an extra point to RCUR so that if we get a plasma it is further out at .26 s (.664 m).
May 16 1997 09:25:28:510AM970516004Ian Hutchinson4. Fiz
CII=.014, Z_m=.015, Ha=0.18 Fill=.017, (was over .02 last shot, this is unreliable).
B_R=+.0035

B_R offset to .006 from .0065.
May 16 1997 09:38:29:850AM970516005Ian Hutchinson5. Dud
Fill=.019, B_R=.003.

Br back to .0065, EF3 V to 2200V at .01s.
May 16 1997 09:52:06:660AM970516006Ian Hutchinson6. Dud. This is seem to have a big teflon burst before the gas fill. This probably explains the
fluctuating fill pressures. The shot that went did not have one, or it was very small.

Repeat.
May 16 1997 09:59:52:820AM970516007Ian Hutchinson7. Dud. Small teflon puff.

Reload shot 4.
May 16 1997 10:14:13:110AM970516008Ian Hutchinson8 Dud. Fill=.018.

Repeat
May 16 1997 10:23:26:550AM970516009Ian Hutchinson9. Dud . Fill .016.

Br offset to .004.
May 16 1997 10:31:08:480AM970516010Ian Hutchinson10. Dud.

EF4 to -1365 from -1375.
May 16 1997 10:41:27:620AM970516011Ian Hutchinson11. Dud.

OH1V to 150 V at 5ms from 75 V.
May 16 1997 10:49:39:830AM970516012Ian Hutchinson12. Dud

Br offset to .005.
May 16 1997 11:01:33:780AM970516013Ian Hutchinson13. Dud

EF4 back to -1375. Increase fill puff to 26ms from 25.
May 16 1997 11:12:00:030AM970516014Ian Hutchinson14. Fiz. CII=.02. Z_m=.2, Ha=.23, Fill=.025. Breakdown at 8ms.
Teflon puff.


EF2L Voltage to -500 from -600 at 0s.
May 16 1997 11:23:22:380AM970516015Ian Hutchinson15. Fiz . CII .015, Z_m=.16. Ha=.27, Fill=.018. Breakdown at 6.6ms. Some current.

EF2L Voltage to -400V.
OH1 Voltage to 150V at .01s from 100.
May 16 1997 11:32:47:600AM970516016Ian Hutchinson16 Dud. Fill .017

EF2L Voltage to 500V.
May 16 1997 11:38:57:220AM970516017Ian Hutchinson17 Dud. Camac Errors. Magnetics data messed up.Fill =.017.

Fill to 27 ms.
May 16 1997 11:49:05:550AM970516018Ian Hutchinson18 Fiz. Fill .018. Late breakdown 12 ms. Still some engineering Camac erros.

OH1 to -20900 from -20750 A.
May 16 1997 11:58:40:110AM970516019Ian Hutchinson19 Dud. Got OH1 -20672.Index went the wrong way.

OH1 current to -20600.
May 16 1997 12:07:03:620PM970516020Ian Hutchinson20 Fiz. Fill=.18. Bkdown at 8ms. CII=.02. Ha=.3. No teflon. 35kA.
Field a bit more negative.

EF4 to -1365.
May 16 1997 12:17:26:260PM970516021Ian Hutchinson21 Fiz.Bkdown at 13ms.

EF4 to -1355.
May 16 1997 12:23:59:010PM970516022Ian Hutchinson22 Dud.

EF4 to -1380.
May 16 1997 12:33:28:490PM970516023Ian Hutchinson23 Plasma .Went for. .35s. Got horribly resistive and ramped down, with disruptions.
Breakdown at 10ms.

Fill to 29ms.
May 16 1997 12:46:22:750PM970516023Ian Hutchinson24 Dud.


EF4 to 1370.
May 16 1997 12:54:34:950PM970516025Ian Hutchinson25 Dud

OH1V to 180V at 5ms. EF4 to -1360.
May 16 1997 01:07:35:650PM970516025Ian Hutchinson25 Fiz.Breakdown at 7ms. 35kA CII .016, Fill .019.Ha .33.

Br offset to .0055 from .005.
May 16 1997 01:14:43:820PM970516027Ian Hutchinson27. Fiz Slightly more current.. 6 ms breakdown.

OH1 to 120V at 1ms.
May 16 1997 01:26:38:570PM970516028Ian Hutchinson28 Fiz. Got 38kA plus a little blip. 6ms breakdown. CII .01 but a blip at the end.

OH1 V to 150 at 8ms (extra point). Small tweak.
May 16 1997 01:36:24:920PM970516029Ian Hutchinson29. Fiz. 38kA again.

OH2 V to 0 at 15ms.
May 16 1997 01:47:13:600PM970516030Ian Hutchinson30 Fiz. About the same.

Fill to 28 ms. OH2 to 10 at 15 ms.
May 16 1997 01:54:22:640PM970516031Ian Hutchinson31 Dud.

Fill back to 29ms.
May 16 1997 02:03:56:410PM970516032Ian Hutchinson32. Fiz Back to where we were.

OH2 to -5 from -10V at 10ms.
May 16 1997 02:19:44:550PM970516033Ian Hutchinson33. Plasma Runs to .4s and then a vertical instability. CII=.01. Ha .3,
Seems to need a slower field ramp during the initial current rise.

Reduce clearin by about .5cm to -.5cm.
May 16 1997 02:29:33:810PM970516034Ian Hutchinson34. Fiz. Slightly late (8ms )breakdown.

Br offset to 5. from 5.5 mT.
May 16 1997 02:40:48:200PM970516035Ian Hutchinson35 Fiz. Breakdown even later, 10 ms. Weak.

Lower clearin even more to -1cm. Raise fill to 31ms.
May 16 1997 02:52:50:440PM970516036Ian Hutchinson36 Fiz. Breakdown at 7ms. Camac errors.

Raise OH1 in the 15-20ms band.
May 16 1997 02:59:39:540PM970516037Ian Hutchinson37. Dud. Suspision of a small teflon puff.

Repeat.
May 16 1997 03:07:23:390PM970516038Ian Hutchinson38 Fiz. No teflon puff. Strange second restrike. Breakdown at 6ms.

OH1 tweak at 8-10 ms to increase bz ramp rate slightly.
May 16 1997 03:26:25:750PM970516039Ian Hutchinson39 Fiz. Partial restrike.

Tweaked down the OH2 voltage during 8-12ms.
May 16 1997 03:30:31:310PM970516040Ian Hutchinson40 Fiz. Bounce at 17ms.

Tweak OH2V down some more.
May 16 1997 03:39:10:710PM970516041Ian Hutchinson41 Fiz Spike over 40kA. Nearly went.

More OH2 downward tweaks, a tad earlier.
May 16 1997 03:41:57:450PM970516042Ian Hutchinson42 Fiz. Late breakdown. 11ms.

Repeat
May 16 1997 03:55:54:590PM970516043Ian Hutchinson43. Dud

EF4 to -1365 from -1360
May 16 1997 04:02:17:360PM970516044Ian Hutchinson44 Dud

Gas to 28ms. EF4 to 1355A.
May 16 1997 04:10:20:220PM970516045Ian Hutchinson45 Fiz. Late breakdown 10 ms.

EF4 to -1365.
May 16 1997 04:17:14:530PM970516046Ian Hutchinson46 Fiz. Breakdown at 6.6ms.

EF4 to -1370.
May 16 1997 04:25:03:490PM970516047Ian Hutchinson47 Fiz. Little data.

EF4 to -1375
May 16 1997 04:39:27:910PM970516048Ian Hutchinson48 Fiz Actually got some data.

Fill to 35 ms.
May 16 1997 04:42:33:110PM970516049Ian Hutchinson49 Breakdown at 7ms.

Fill to 38ms.
May 16 1997 04:50:00:540PM970516050Ian Hutchinson50 Fiz.

OH1 to 120V at 7ms.
May 16 1997 05:08:09:600PM970516051Ian Hutchinson51 Late breakdown.. Small Teflon injection.

Reload shot33 lower clearin to 01cm.
May 16 1997 05:08:30:120PM970516052Ian Hutchinson52 Fizzle but looks promising.

Engineering Operator Comments
ShotTimeTypeStatusComment
108:22:07:470AMPlasmaOk
208:39:04:820AMPlasmaOk
309:09:53:810AMPlasmaOk
409:18:03:450AMPlasmaOk
509:26:19:230AMPlasmaOk
609:34:23:840AMPlasmaOk
709:50:33:880AMPlasmaOk
809:58:02:750AMPlasmaOk
910:13:39:300AMPlasmaOk
1010:21:52:550AMPlasmaOk
1110:29:45:460AMPlasmaOk
1210:40:01:750AMPlasmaOk
1310:48:15:240AMPlasmaOk
1410:59:25:020AMPlasmaOk
1511:10:15:480AMPlasmaOk
1611:21:34:520AMPlasmaOk
1711:30:58:830AMPlasmaOk
1811:37:20:470AMPlasmaOk
1911:47:32:110AMPlasmaOk
2011:55:52:670AMPlasmaOk
2112:05:30:250PMPlasmaOk
2212:15:50:430PMPlasmaOk
2312:22:05:710PMPlasmaOk
2412:35:51:440PMPlasmaOk
2512:44:11:640PMPlasmaOk
2612:56:21:100PMPlasmaOk
2701:05:09:150PMPlasmaOk
2801:13:42:220PMPlasmaOk
2901:23:53:330PMPlasmaOk
3001:34:48:530PMPlasmaOk
3101:44:22:650PMPlasmaOk
3201:52:23:570PMPlasmaOk
3302:02:25:480PMPlasmaOk
3402:18:00:370PMPlasmaOk
3502:26:55:190PMPlasmaOk
3602:39:08:280PMPlasmaOk
3702:50:11:640PMPlasmaOk
3802:57:45:160PMPlasmaOk
3903:09:02:680PMPlasmaOk
4003:18:26:530PMPlasmaOk
4103:28:41:640PMPlasmaOk
4203:37:09:720PMPlasmaOk
4303:45:59:210PMPlasmaOk
4403:54:04:650PMPlasmaOk
4504:00:23:060PMPlasmaOk
4604:08:21:230PMPlasmaOk
4704:15:21:860PMPlasmaOk
4804:23:15:770PMPlasmaOk
4904:32:51:660PMPlasmaOk
5004:41:02:160PMPlasmaOk
5104:48:16:320PMPlasmaOk
5204:55:56:780PMPlasmaOk