Alcator C-Mod Run 1031023 Information

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Miniproposals
Miniproposal:
Date Filed:
Title:
First Author:
Session Leader: Unknown (shots 1-24)

Operators
Session leader(s): Unknown
Physics operator(s):Earl Marmar
Engineering operator(s):Bill Parkin,Bill Byford,Gary Dekow

Engineering Operator Run Comment
Plasma startup and conditioning PO: Marmar EO: Dekow/Byford/Parkin

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Physics Operator Summaries
Entered: Jul 7 2004 04:37:19:583PM
Author: Earl Marmar
Physop run summary
1031023


Purpose: Plasma startup and conditioning

Physics operator: Marmar

ECDC overnight in D2 at 2e-4 Torr, stopping by 07:00.
Bake at 60 C overnight as well.

Run begins at 9:00 and ends at 17:00.

Power systems the same as on 1031022004 including control coil settings.

Gas setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar Hybrid enabled (PG1)
fill B-side upper with 10 psi D2 Hybrid DISABLED (PG2) (for ECDC)
fill C-side with 30 psi D2 Hybrid enabled (PG3)

Ninja should be left with its current 200 Torr fill.

Enable the following gate valves: ECE, VUV, DNB

-----------------------------------------------------------------------
RF Setup: Transmitters 1,2,3, and 4 in RUN ON by 8:00 am

-----------------------------------------------------------------------
Run Plan: Continue running cleanup plasmas while monitoring H/D, etc.

RF Group will continue antenna conditioning.
-----------------------------------------------------------------------

Results:

The run went pretty well, with 16 full length plasmas in a row after a
data system hang took out shot 1. At the end of the run, we had 3 duds
and a fizzle interspersed with 3 plasmas. The last shot (24) disrupted
10 msec after the chopper tripped out with failed components. That
ended the run early, at about 3:30 pm.

The duds are a mystery to me; the fields and fill pressures looked
fine. The sparker, to my eye, looks the same as on plasmas, for t<0.

RF made significant progress today, with J-port launching
substantial energy, H-modes on most shots, and total RF power over 4
MW at various times. H/D was still mostly above 10%. Twice we
discharge cleaned for 15 minutes (before shots 13 and 24).In each case
H/D dropped, but not dramatically, especially for the high power RF
portions of the discharges.

The gate valves were kept closed for up to 8 minutes after many shots,
for Bruce to look at wall loading/unloading. He reports that 100 T-l
of gas was released after the 1 MA disruption due to the chopper trip.

All shots today were lower single-null, with Ip from 0.8 to 1.0 MA,
and nl_04 in the range from 7e19 to 1e20 (L-Mode).

Summary

Plasmas: 2-17, 19, 22, 24 (19 total)
Fizzle: 21
Duds: 18,20,23
Test/no power: 1

Total cycles: 24


Session Leader Comments

Physics Operator Comments
Oct 23 2003 08:57:17:100AMEarl MarmarPurpose: Plasma startup and conditioning

Physics operator: Marmar
Engineering operator: Gary Dekow


ECDC overnight in D2 at 2e-4 Torr, stopping by 07:00.
Bake at 60 C overnight as well.

Run begins at 9:00 and ends at 17:00.

Power systems the same as on 1031022004 including control coil settings.

Gas setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar Hybrid enabled (PG1)
fill B-side upper with 10 psi D2 Hybrid DISABLED (PG2) (for ECDC)
fill C-side with 30 psi D2 Hybrid enabled (PG3)

Ninja should be left with its current 200 Torr fill.

Enable the following gate valves: ECE, VUV, DNB

-----------------------------------------------------------------------
RF Setup: Transmitters 1,2,3, and 4 in RUN ON by 8:00 am

-----------------------------------------------------------------------
Run Plan: Continue running cleanup plasmas while monitoring H/D, etc.

RF Group will continue antenna conditioning.
-------------------------------------------------------------------------------

Oct 23 2003 05:54:07:540PMEarl MarmarPhysop run summary
1031023


Purpose: Plasma startup and conditioning

Physics operator: Marmar

ECDC overnight in D2 at 2e-4 Torr, stopping by 07:00.
Bake at 60 C overnight as well.

Run begins at 9:00 and ends at 17:00.

Power systems the same as on 1031022004 including control coil settings.

Gas setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar Hybrid enabled (PG1)
fill B-side upper with 10 psi D2 Hybrid DISABLED (PG2) (for ECDC)
fill C-side with 30 psi D2 Hybrid enabled (PG3)

Ninja should be left with its current 200 Torr fill.

Enable the following gate valves: ECE, VUV, DNB

-----------------------------------------------------------------------
RF Setup: Transmitters 1,2,3, and 4 in RUN ON by 8:00 am

-----------------------------------------------------------------------
Run Plan: Continue running cleanup plasmas while monitoring H/D, etc.

RF Group will continue antenna conditioning.
-----------------------------------------------------------------------

Results:

The run went pretty well, with 16 full length plasmas in a row after a
data system hang took out shot 1. At the end of the run, we had 3 duds
and a fizzle interspersed with 3 plasmas. The last shot (24) disrupted
10 msec after the chopper tripped out with failed components. That
ended the run early, at about 3:30 pm.

The duds are a mystery to me; the fields and fill pressures looked
fine. The sparker, to my eye, looks the same as on plasmas, for t<0.

RF made significant progress today, with J-port launching
substantial energy, H-modes on most shots, and total RF power over 4
MW at various times. H/D was still mostly above 10%. Twice we
discharge cleaned for 15 minutes (before shots 13 and 24).In each case
H/D dropped, but not dramatically, especially for the high power RF
portions of the discharges.

The gate valves were kept closed for up to 8 minutes after many shots,
for Bruce to look at wall loading/unloading. He reports that 100 T-l
of gas was released after the 1 MA disruption due to the chopper trip.

All shots today were lower single-null, with Ip from 0.8 to 1.0 MA,
and nl_04 in the range from 7e19 to 1e20 (L-Mode).

Summary

Plasmas: 2-17, 19, 22, 24 (19 total)
Fizzle: 21
Duds: 18,20,23
Test/no power: 1

Total cycles: 24

Oct 23 2003 09:14:11:223AM1031023001Earl Marmarload from 1031022010, 0.8 MA lower single null, 0.8e20 nl_04

no power shot; iogr problem
Oct 23 2003 09:36:39:427AM1031023002Earl Marmartry again

plasma

2 H-Mode periods

H/(H+D) = .05 to .10
Oct 23 2003 09:52:21:597AM1031023003Earl Marmarno pcs changes

plasma; 1 H-mode

H/(H+D) = .07 to .11
Oct 23 2003 10:11:42:873AM1031023004Earl Marmarno pcs changes

plasma; 2 short H-modes

H/(H+D) = .09 to .13
Oct 23 2003 10:33:37:160AM1031023006Earl Marmaradd 800 A to A-coil demand (now 3800)
Ip demand to 850 kA (from 800)
nl_04 to 7e19 (from 6e19)

after the shot, gate valves will be closed for 8 minutes (blip experiment)

plasma; 1 H-mode

H/(H+D) = .1 to .14
Oct 23 2003 10:59:16:647AM1031023007Earl Marmaradd 800 A to A-coil demand (now 4600)
I_p demand to 900 kA
nl_04 to 8e19

plasma; no H-mode; much less RF power

H/(H+D) = .1 to .12

Did not get increase in A-coil current; PLC limit
Oct 23 2003 11:11:26:060AM1031023008Earl Marmarno pcs changes

plasma; 2 H-mode periods
got more current on A-coils this time

H/(H+D) = .1 to .13
Oct 23 2003 11:26:45:387AM1031023009Earl Marmarno pcs changes

plasma; 1 short H-mode, while RF reaches 4MW total
startup starting to look a little off: second peak on H-alpha and CII (seen on shot 8 also)

H/(H+D) = .10 to .13
Oct 23 2003 11:42:48:103AM1031023010Earl Marmarno pcs changes

plasma; no h-mode

H/(H+D) = .09 to .13
Oct 23 2003 11:59:26:583AM1031023011Earl Marmarno pcs changes

plasma; 1 H-mode period
something fell in at .125 seconds, took a bite out of I_p

H/(H+D) = .1 to .13
Oct 23 2003 12:14:38:917PM1031023012Earl Marmartweak I_p gain at 0.6 seconds
speed I_p rampdown slightly

plasma; 1 short H-mode period

H/(H+D) = .08 to .13

ECDC for 15 minutes before the next shot (D_2, 2e-4 torr guage)
Oct 23 2003 12:45:14:133PM1031023013Earl Marmar15 minutes ECDC before this shot (D_2, 2e-4 torr guage)

no pcs changes
plasma; 3 H-mode periods

H/(H+D) = .06 to .12
Oct 23 2003 12:57:50:180PM1031023014Earl Marmarno pcs changes

plasma; 1 H-mode period

H/(H+D) = .08 to .12
Oct 23 2003 01:16:32:620PM1031023015Earl Marmarreduce nl_04 demand to 7e19 (from 8e19)

plasma; 2 H-mode periods

H/(H+D) = .1 to .14
Oct 23 2003 01:27:06:870PM1031023016Earl Marmarno pcs changes

plasma; 2 H-mode periods

H/(H+D) = .1 to .13
Oct 23 2003 01:38:58:930PM1031023017Earl MarmarDecrease TF current to 147 kA (from 150) after 0.1 s

plasma; 2 H-mode periods

H/(H+D) = .1 to .135

Oct 23 2003 01:57:34:790PM1031023018Earl MarmarI_p demand to 1.0 MA

dud
fields look ok
Oct 23 2003 02:11:25:260PM1031023019Earl Marmaradd 2 msec to prepuff

plasma; a couple of H-mode periods

H/(H+D) = .1 to .14
Oct 23 2003 02:18:55:070PM1031023020Earl Marmarno pcs changes

dud
fields still look ok
Oct 23 2003 02:34:29:493PM1031023021Earl Marmaradd 1 msec to prefill puff

fizzle
Oct 23 2003 02:54:38:197PM1031023022Earl MarmarEF4 10 A more negative

plasma; 3 H-mode periods

H/(H+D) = .1 to .15
Oct 23 2003 03:03:20:463PM1031023023Earl Marmarno pcs changes

dud

fields look fine

15 minutes of ECDC before the next shot (D_2, 2e-4 torr guage)
Oct 23 2003 03:53:24:540PM1031023024Earl Marmarecdc for 15 minutes before the shot (D_2, 2e-4 Torr guage)

plasma
disrupt at .99 seconds; looks like the chopper suddenly turned off about 10 msec prior to disruption

H/(H+D) = .07 to .09

on further investigation, components on the chopper have clearly gone bad.

This is the last shot of the run.

Engineering Operator Comments
ShotTimeTypeStatusComment
109:02:48:150AMTestBad
209:27:58:437AMPlasmaOk
309:41:48:680AMPlasmaOk
409:55:13:113AMPlasmaOk
510:10:01:310AMPlasmaOk
610:23:37:150AMPlasmaOk
710:48:30:543AMPlasmaOk
811:01:43:930AMPlasmaOk
911:18:33:083AMPlasmaOk
1011:33:36:563AMPlasmaOk
1111:49:36:043AMPlasmaOk
1212:04:16:273PMPlasmaOk
1312:35:17:650PMPlasmaOk
1412:49:08:180PMPlasmaOk
1501:02:32:980PMPlasmaOk
1601:16:44:540PMPlasmaOk
1701:30:41:807PMPlasmaOk
1801:47:45:980PMPlasmaOk
1902:01:34:603PMPlasmaOk
2002:14:50:637PMPlasmaOk
2102:30:20:853PMPlasmaOk
2202:43:48:057PMPlasmaOk
2302:57:08:027PMPlasmaOk
2403:27:21:493PMPlasmaOkpossible EFC problem