Alcator C-Mod Run 951116 Information

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Miniproposals
Miniproposal:062
Date Filed: 6/16/1994
Title:PCX Beast commissioning
First Author:Rejean Boivin
Session Leader:Rejean Boivin (shots 1-7)

Operators
Session leader(s):Rejean Boivin
Physics operator(s):Earl Marmar
Engineering operator(s):Frank Silva

Engineering Operator Run Comment
Q-Profiles Marmer/Garnier

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Physics Operator Summaries
Entered: Jul 7 2004 04:36:55:410PM
Author: To Be Determined
EO Silva
PO Marmar
SL Boivin

951116

start from 951115034; reduce b-top plenum pressure to 5 psi; lengthen pre-pulse to 15 msec

1. pulsed gas test; no power; F-port nude gauge gives 1.25e-5 at t=0
2. add 3 ms to B top pare-pulse; try for plasma; power supply problems - no EF2, EFC; got 1.4e-5 at t=0
3. retry; fizzle; got 1.5e-5
4. 2 msec off pre-pulse; fizzle; got 1.25e-5
5. 2 msec off pre-pulse; fizzle; got 1.05e-5
6. 1 msec off pre-pulse; EF4 20 amp less negative at t=0; fizzle
7. B_R tweak (1 mT less positive); fizzle

We noticed that the base pressure betweeen shots seemed high and mass 18 was high on the RGA. After some looking, we discovered
there had been a vacuum event at about 8:00 am, shortly after ECDC was turned off. The RGA's show evidence of an air burst. 3 ion
gauges turned off. The TC gauges also show the burst.

Suspended the run to bake (60 C) and ECDC.

ECDC broke at 11:30 (magnetron power supply problems). At 2:30, we decided to abandon the run for today; at that time, mass 18
partial pressure on the new RGA, with the cryopump open to the machine, was 1e-7. On Monday, with the machine at the same
temperature (60 C) it was 1e-8.

Session Leader Comments
Nov 16 1995 08:34:41:450AMRejean BoivinWe will start today's run pursueing cross-calibration of the PCX
and realignment (internal) of HIREX. We will start repeating shot
034 from yesterday's run. We will then move to RF and LPI conditioning.

Nov 16 1995 08:36:07:480AM951116001Rejean BoivinFirst shot is a gas puff test only. We'll shoot (and score) on
the next shot.

Nov 16 1995 08:46:53:260AM951116002Rejean BoivinDud, some power supplies didn't go.

Nov 16 1995 08:54:49:880AM951116003Rejean BoivinFizzle, missed by not much.

Nov 16 1995 10:01:42:110AM951116004Rejean BoivinFizzle.

Nov 16 1995 10:01:46:980AM951116005Rejean BoivinFizzle.

Nov 16 1995 10:01:52:470AM951116006Rejean BoivinFizzle.

Nov 16 1995 10:02:06:920AM951116007Rejean BoivinFizzle. Water the problem?

Physics Operator Comments

Engineering Operator Comments
ShotTimeTypeStatusComment
108:32:23:210AMTestOkgas test
208:42:17:490AMPlasmaOkno ef2, efc, no plc programing
308:50:03:620AMPlasmaOk
408:59:57:250AMPlasmaOkoh2 upper fault
509:11:26:690AMPlasmaOkoh2 fault
609:26:35:490AMPlasmaOk
709:39:50:850AMPlasmaOkno faults