Alcator C-Mod Run 951115 Information

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Miniproposals
Miniproposal:048
Date Filed: 4/8/1994
Title:HIREX Troubleshooting
First Author:John Rice
Session Leader:John Rice (shots 1-34)
Miniproposal:062
Date Filed: 6/16/1994
Title:PCX Beast commissioning
First Author:Rejean Boivin
Session Leader:Rejean Boivin (shots 1-34)

Operators
Session leader(s):Rejean Boivin,John Rice
Physics operator(s):Joseph Snipes
Engineering operator(s):Vinny Bertolino

Engineering Operator Run Comment
Hirex/beast

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:13:977PM
Author: To Be Determined

Run 951115

PCX Cross-calibration/Commisionning MP062A
Hirex restart MP048


SL R. Boivin and J. Rice
PO J. Snipes
Eng V. Bertolino


We are attempting to have a long series of reproducible shots
in order to cross-calibrate the channels of the Perpendicular
Charge-Exchange (PCX) (78 channels, 39 for each mass). Some
of them were changed (and some fixed) over the summer break.
The alignment was also slightly modified. By the same token
we are restarting HIREX and verify internal alignment and try
to debug the system.

We will use a 0.8 MA, 5.3T shot with low(ish) density,
anything near 5-6x10^19 nel, which can be easily reproduced.


951115

001 Shot went through nicely, density 8x10^19 a bit
above request, we will try to reduce a bit.

002 Fizzle, attempt to lower density. Not sure why it fizzled.

003 Good shot, density is about right, Stay at this level.
Very good signal on PCX.

004 Another good one, go for it Joe!

005 A good one, "natural" moly injection around 0.8 sec.

006 Still good, disruption on the way down. Not sure why?

007 Fizzle, result of disruption?

008 Oh well, another fizzle.

009 Actually a DUD, gas problem??

010 Dud, trying to get the gas right.

011 Fizzle, not quite enough gas.

012 Good shot, increase pre-puff gas.

013 Fizzle.

014 Good shot, will have to keep an eye on the gas...

015 Fizzle, Cleaning the machine???

016 Good shot, density still holding.

017 Good one, disrupted on the way down, we'll pay for that...

018 Fizzle, to be expected. Carbon really high.

019 Another fizzle, we'll get the machine cleaned someday.

020 Another fizzle.

021 Good Shot, carbon the problem, or simply gas??

022 Fizzle.

023 Gas test only, using B top only. No Argon.

024 Another gas test.

025 Good shot, piece of moly junk at 0.9 sec, then disrupted on the
way down.

026 Fizzle. After a disruption!!!

027 Good shot.

028 ANother good one, all the way down.

029 Another good one, Keep going, all the way down.

030 Still pretty good, don't touch that dial!

031 Joe wants to change Br, ok go ahead, good shot.

032 Fizzle.

033 Shot went through but with HArd X-rays at beginning.

034 Shot went, very little hards at beginning.


Stats for today:

Plasmas: 18
Fizzles: 12
Duds: 2
Tests: 2



Physics Operator Summaries
Entered: Jul 7 2004 04:36:55:207PM
Author: To Be Determined
Diagnostic development run for HIREX and PCX 951115.
Session Leaders: Rejean Boivin and John Rice
Physics Operator: Joseph Snipes
Engineer in Charge: Vince Bertolino

Standard 0.8 MA, 5.5 T, medium density discharges throughout the day for
checking out HIREX and PCX. Using the new pulse gas system with only a
puff instead of prefill.

The run went reasonably well. There were problems getting reliable current
rises leading to quite a number of fizzles. The gas programming with a
pre-puff instead of pre-fill has now been tuned up and should prove quite
reliable for future runs. Still, the neutral pressure at breakdown needs
to be watched carefully during the day because it seems that longer
pre-puffs are required as the wall conditioning improves. The last shot,
34, was probably the best one to start from with a 9 msec flattop of the
pre-puff. Now that the pre-puff is set to -0.51 sec, the exact timing of
the puff is no longer critical because the pressure is relatively constant
for at least 200 msec around t=0 (without plasma, see shot 951115024).
There were some problems with TF cooling that slowed down the run
significantly. Otherwise, the engineering systems worked quite well.
There were a few computer problems, but they were quickly resolved by Josh.

Scorecard: 18 plasmas, 12 fizzles, 2 duds, 2 test shots

Shot 1 : Copied shot 951114031 lengthening the Ar puff by a couple of msec
and reducing the programmed density to 6 x 10^19 m^-2. Good shot.
Shot 2 : Reduced programmed density to 5 x 10^19 m^-2. Fizzle!
Shot 3 : Repeat. Good shot.
Shot 4 : Reduced pre-programmed gas puffing to try to get down to the
requested density. Raised requested density to 6 x 10^19 m^-2. Good shot.
Shot 5 : Repeat. Good shot. Natural Moly injection at 0.76 sec.
Shot 6 : Repeat. Good shot. Disruption in rampdown.
Shot 7 : Repeat. Fizzle!
Shot 8: Repeat. Fizzle!
Shot 9 : Repeat. Dud!
Shot 10: Disabled B top early gas puff. Dud!
Shot 11: Re-enabled B top puff and added 1 msec more to the puff. Fizzle!
Shot 12: Added another msec to the B top early puff to make it 6 msec long.
Good shot.
Shot 13: Repeat. Fizzle!
Shot 14: Returned B top early puff to 5 msec duration. Good shot.
Shot 15: Repeat. Fizzle!
Shot 16: Tweaked B top pre-puff to make it a bit longer. 6 ms flattop with
2 ms rise and fall times. Good shot.
Shot 17: Added another ms to the B top pre-puff flattop. Good shot.
Disrupted at 1.16 sec. Density data lost.
Shot 18: Repeat. Fizzle! CII level up to 0.04 mW/cm^2/ster.
Shot 19: Repeat. Fizzle!
Shot 20: Repeat. Fizzle!
Shot 21: Reduced Br offset from 7.5 mT to 7.0 mT. Reduced B top pre-puff by
another ms to 6 ms flattop with 1 ms rise and fall times. Good shot.
Shot 22: Repeat. Fizzle!
Shot 23: Test shot with B top gas puff only, no fields. A side and B side
gas valves disabled. B top gas puff moved to -0.41 sec. B top pressure
set to 5 lbs.
Shot 24: Test shot with B top gas puff only. B top puff moved to -0.51
sec. B top pressure changed to 10.8 lbs. Flattop increased to 7 ms.
Shot 25: Real shot with new gas pre-puff arrangement. Good shot. Natural
Moly injection at 0.91 sec. Disrupted at 1.3 sec.
Shot 26: Repeat. Fizzle.
Shot 27: Br offset changed to 7.5 mT. Good shot.
Shot 28: Br offset changed to 8 mT. Good shot.
Shot 29: Repeat. Good shot. Density data lost.
Shot 30: Repeat. Good shot. Density data returned.
Shot 31: Repeat. Good shot.
Shot 32: Reduced rate of rise of EF4U from 0 to 0.03 sec. Fizzle!
Shot 33: Returned to shot 31. Good shot. Hard x rays for most of the shot.
Shot 34: Increased B top pre-puff by 2 msec to 9 msec flattop. Good shot.

Session Leader Comments
Nov 15 1995 09:15:38:890AMRejean BoivinFor today's run 951115, we will attempt to have many reproducible
shots in order to cross-calibrate the channels (78) of the
Perpendicular Charge-Exchange (PCX) of which some were replaced
over the summer break. AT the same time we will debug HIREX and
investigate some of the internal problems. Consequently we
will ask for low density (~5-6 x 10^19 nel) and repeat all
day...

Nov 15 1995 09:17:28:310AM951115001Rejean BoivinFirst shot of the day, A good one. Density is a bit above what we
requested so we will try to reduce it a little bit

Nov 15 1995 09:18:02:380AM951115002Rejean BoivinFizzle. Will try again to start the sequence...

Nov 15 1995 09:44:55:700AM951115003Rejean BoivinGood shot, density is pretty good, stay at this level.

Nov 15 1995 10:01:17:550AM951115004Rejean BoivinGood shot, density is pretty good, stay at this level. Hopefully
we will be able to keep it that way.

Nov 15 1995 10:25:14:520AM951115005Rejean BoivinGood shot, density is changing a bit. Natural moly injection
around 0.8 sec. We will do some ECE alignment check, see entries
by Amanda.

Nov 15 1995 10:42:58:810AM951115006Rejean BoivinGood shot, disruption on the way down.

Nov 15 1995 10:48:39:020AM951115007Rejean BoivinFizzle! After disruption????

Nov 15 1995 10:59:10:930AM951115008Rejean BoivinFizzle! What's next?

Nov 15 1995 11:06:53:670AM951115009Rejean BoivinFizzle! Maybe too much gas?

Nov 15 1995 11:20:06:720AM951115010Rejean BoivinDUD, Trying to get gas right.

Nov 15 1995 11:43:05:040AM951115012Rejean BoivinGood shot, gas a little bit tricky.

Nov 15 1995 12:08:13:720PM951115013Rejean BoivinFizzle, gas?

Nov 15 1995 12:08:41:980PM951115014Rejean BoivinGood shot, density is still pretty close to original so
scan is still going on.

Nov 15 1995 12:16:41:840PM951115015Rejean BoivinFizzle, cleaning up the machine?

Nov 15 1995 12:40:45:700PM951115016Rejean BoivinNice shot, scan still going on.

Nov 15 1995 01:05:54:970PM951115017Rejean BoivinNice shot, scan still going on. Disrupted on the way, we'll pay
for that I am afraid...

Nov 15 1995 01:06:36:460PM951115018Rejean BoivinFizzle, as to be expected. Carbon high.

Nov 15 1995 01:25:07:790PM951115019Rejean BoivinAnother fizzle, clean it up...

Nov 15 1995 01:35:16:240PM951115020Rejean BoivinAnother one in the fizzle column.

Nov 15 1995 01:59:32:160PM951115021Rejean BoivinA good shot, gas versus carbon, the problem??

Nov 15 1995 01:59:47:390PM951115022Rejean BoivinFizzle.

Nov 15 1995 02:34:11:330PM951115023Rejean BoivinGas test only.

Nov 15 1995 02:34:18:900PM951115024Rejean BoivinGas test only.

Nov 15 1995 02:34:57:940PM951115025Rejean BoivinGood shot, moly crud injection at 0.9 sec. and then disrupted on
the way down. We may have to pay for that one...

Nov 15 1995 02:53:57:600PM951115026Rejean BoivinFizzle.

Nov 15 1995 03:12:19:700PM951115027Rejean BoivinGood shot, all the way down.

Nov 15 1995 03:12:26:670PM951115028Rejean BoivinGood shot, all the way down.

Nov 15 1995 03:23:18:950PM951115029Rejean BoivinGood shot, all the way down. We'll keep going.

Nov 15 1995 04:00:52:120PM951115030Rejean BoivinGood shot, all the way down. We'll keep going.

Nov 15 1995 04:01:21:310PM951115031Rejean BoivinGood shot, all the way down. We'll keep going. Keep changing
Br a little bit. Keeps Joe busy.

Nov 15 1995 04:18:27:290PM951115032Rejean BoivinFizzle, bleauh.

Nov 15 1995 04:48:10:970PM951115033Rejean BoivinShot went through, Hard X-rays at beginning.

Nov 15 1995 05:15:14:300PM951115034Rejean BoivinShot went through, maybe a few hards at beginning. Data acq
had problems.

Physics Operator Comments
Nov 15 1995 08:51:18:570AMJoseph SnipesThis is a diagnostic development run for HIREX and PCX with Rejean Boivin
and John Rice sharing the leader role and Joseph Snipes as PhysOp. Vince
Bertolino is Engineer in Charge. We intend to run 800 kA, 5.3 T
medium density shots all day long.

Nov 15 1995 05:26:14:050PMJoseph SnipesThe run went reasonably well. There were problems getting reliable current
rises leading to quite a number of fizzles. The gas programming with a
pre-puff instead of pre-fill has now been tuned up and should prove quite
reliable for future runs. Still, the neutral pressure at breakdown needs
to be watched carefully during the day because it seems that longer
pre-puffs are required as the wall conditioning improves. The last shot,
34, was probably the best one to start from with a 9 msec flattop of the
pre-puff. Now that the pre-puff is set to -0.51 sec, the exact timing of
the puff is no longer critical because the pressure is relatively constant
for at least 200 msec around t=0 (without plasma, see shot 951115024).

Nov 15 1995 08:51:43:110AM951115001Joseph SnipesCopied shot 951114031 lengthening the Ar puff by a couple of msec and
reducing the programmed density to 6 x 10^19 m^-2.

Nov 15 1995 09:31:10:610AM951115002Joseph SnipesShot 2 : Reduced programmed density to 5 x 10^19 m^-2. Fizzle!

Nov 15 1995 09:32:27:710AM951115003Joseph SnipesShot 3: Repeat. Good shot.

Nov 15 1995 09:56:25:330AM951115004Joseph SnipesShot 4 : Reduced pre-programmed gas puffing to try to get down to the
requested density. Raised requested density to 6 x 10^19 m^-2. Good shot.

Nov 15 1995 10:00:02:630AM951115004Joseph SnipesShot 4 : Reduced pre-programmed gas puffing to try to get down to the
requested density. Raised requested density to 6 x 10^19 m^-2.

Nov 15 1995 10:26:21:790AM951115005Joseph SnipesShot 5 : Repeat. Good shot. Natural Moly injection at 0.76 sec.

Nov 15 1995 10:59:39:100AM951115006Joseph SnipesShot 6 : Repeat. Good shot. Disruption in rampdown.

Nov 15 1995 10:54:41:910AM951115007Joseph SnipesShot 7 : Repeat. Fizzle!

Nov 15 1995 11:04:27:530AM951115008Joseph SnipesShot 8: Repeat. Fizzle!

Nov 15 1995 11:16:02:850AM951115009Joseph SnipesShot 9 : Repeat. Dud!

Nov 15 1995 11:27:44:650AM951115010Joseph SnipesShot 10: Disabled B top early gas puff. Dud!

Nov 15 1995 11:35:10:860AM951115011Joseph SnipesShot 11: Re-enabled B top puff and added 1 msec more to the puff.
Fizzle!

Nov 15 1995 11:39:38:790AM951115012Joseph SnipesShot 12: Added another msec to the B top early puff to make it 6 msec long.
Good shot.

Nov 15 1995 11:56:43:070AM951115013Joseph SnipesShot 13: Repeat. Fizzle!

Nov 15 1995 12:00:02:670PM951115014Joseph SnipesShot 14: Returned B top early puff to 5 msec duration. Good shot.

Nov 15 1995 12:28:20:890PM951115015Joseph SnipesShot 15: Repeat. Fizzle!

Nov 15 1995 12:30:05:150PM951115016Joseph SnipesShot 16: Tweaked B top pre-puff to make it a bit longer. 6 ms flattop with
2 ms rise and fall times. Good shot.

Nov 15 1995 01:03:59:370PM951115017Joseph SnipesShot 17: Added another ms to the B top pre-puff flattop. Good shot.
Disrupted at 1.16 sec. Density data lost.

Nov 15 1995 01:04:13:240PM951115018Joseph SnipesShot 18: Repeat. Fizzle! CII level up to 0.04 mW/cm^2/ster.

Nov 15 1995 01:21:31:590PM951115019Joseph SnipesShot 19: Repeat. Fizzle!

Nov 15 1995 01:39:51:280PM951115020Joseph SnipesShot 20: Repeat. Fizzle!

Nov 15 1995 01:42:28:960PM951115021Joseph SnipesShot 21: Reduced Br offset from 7.5 mT to 7.0 mT. Reduced B top pre-puff by
another ms to 6 ms flattop with 1 ms rise and fall times. Good shot.

Nov 15 1995 02:04:29:830PM951115022Joseph SnipesShot 22: Repeat. Fizzle!

Nov 15 1995 02:19:26:910PM951115023Joseph SnipesShot 23: Test shot with B top gas puff only, no fields. A side and B side
gas valves disabled. B top gas puff moved to -0.41 sec. B top pressure
set to 5 lbs.

Nov 15 1995 02:39:22:740PM951115024Joseph SnipesShot 24: Test shot with B top gas puff only. B top puff moved to -0.51
sec. B top pressure changed to 10.8 lbs. Flattop increased to 7 ms.

Nov 15 1995 02:39:40:860PM951115025Joseph SnipesShot 25: Real shot with new gas pre-puff arrangement. Good shot. Natural
Moly injection at 0.91 sec. Disrupted at 1.3 sec.

Nov 15 1995 02:50:37:710PM951115026Joseph SnipesShot 26: Repeat. Fizzle.

Nov 15 1995 03:01:27:920PM951115027Joseph SnipesShot 27: Br offset changed to 7.5 mT. Good shot.

Nov 15 1995 03:06:41:310PM951115028Joseph SnipesShot 28: Br offset changed to 8 mT. Good shot.

Nov 15 1995 03:17:43:420PM951115029Joseph SnipesShot 29: Repeat. Good shot.

Nov 15 1995 03:36:50:450PM951115030Joseph SnipesShot 30: Repeat. Good shot. Density data returned.

Nov 15 1995 04:26:11:380PM951115031Joseph SnipesShot 31: Repeat. Good shot.

Nov 15 1995 04:26:25:350PM951115032Joseph SnipesShot 32: Reduced rate of rise of EF4U from 0 to 0.03 sec. Fizzle!

Nov 15 1995 04:42:06:040PM951115033Joseph SnipesShot 33: Returned to shot 31. Good shot.

Nov 15 1995 05:24:57:380PM951115034Joseph SnipesShot 34: Increased B top pre-puff by 2 msec to 9 msec flattop. Good shot.
No hard x rays.

Engineering Operator Comments
ShotTimeTypeStatusComment
108:51:08:620AMPlasmaOk
209:05:34:890AMPlasmaOk
309:29:26:410AMPlasmaOk
409:44:39:050AMPlasmaOk
510:14:24:810AMPlasmaOk
610:29:44:420AMPlasmaOk
710:46:07:330AMPlasmaOk
810:54:53:660AMPlasmaOk
911:04:51:790AMPlasmaOk
1011:14:01:360AMPlasmaOk
1111:26:59:320AMPlasmaOk
1211:37:23:150AMPlasmaOk
1311:49:04:330AMPlasmaOk
1411:58:21:850AMPlasmaOk
1512:13:50:820PMPlasmaOk
1612:28:16:970PMPlasmaOk
1712:42:06:770PMPlasmaOk
1812:55:39:140PMPlasmaOk
1901:14:34:280PMPlasmaOk
2001:25:01:460PMPlasmaOk
2101:41:00:580PMPlasmaOk
2201:54:46:030PMPlasmaOk
2302:08:51:580PMTestOk
2402:20:20:790PMTestOk
2502:27:20:350PMPlasmaOk
2602:39:37:080PMPlasmaOk
2702:52:03:360PMPlasmaOk
2803:04:50:160PMPlasmaOk
2903:15:27:730PMPlasmaOk
3003:32:42:810PMPlasmaOk
3103:51:20:830PMPlasmaOk
3204:15:47:620PMPlasmaOk
3304:39:15:950PMPlasmaOk
3404:58:40:370PMPlasmaOk