Alcator C-Mod Run 1030515 Information

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Miniproposals
Miniproposal:329
Date Filed:10/25/2002
Title:Plasma Initiation without Commutation.
First Author:Ian Hutchinson
Session Leader:Steve Wolfe (shots 1-34)
Session Leader:Ian Hutchinson (shots 1-34)

Operators
Session leader(s):Steve Wolfe,Ian Hutchinson
Physics operator(s):Ian Hutchinson
Engineering operator(s):Gary Dekow

Engineering Operator Run Comment
Boronization Recovery/RF conditioning; SL:Hutch/Wolfe; PO: Hutch; EO:Dek

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Physics Operator Summaries
Entered: Jul 7 2004 04:37:17:787PM
Author: To Be Determined

Physop Summary for 1031515 Thursday, 15 May 2003

MP 329 Plasma Initiation without Commutation.
Session leader: Hutch/Wolfe
Physics operator: Hutch

Summary
_______

The major objective of demonstrating plasma initiation without
commutation was achieved. Two full-length plasmas were obtained.
However, despite early successes, a problem with frequent duds, even on
settings that had previously run today with full plasmas, was
encountered. Several sallies into surrounding parameter space were
undertaken without discovering a place that was obviously better than
the configuration of the shots that went. Therefore it remains to be
established whether the commutationless startup is or can be made
robust.

It was demonstrated that we have plenty of power supply flexibility to
control field and null configuration and evolution at loop voltages up
to almost 6V per turn without commutation. Earliest ionization occurs
at about t=10 ms. This is reasonably in accord with a scaling t.E =
constant.

Scorecard
_________

In lieu of the usual scorecard, a summary table of shots.

03 Standard shot for fiducial.

ms
Shot Bdwn Ip(kA) Bz@10ms. Br@10ms Null description
04 16 0 2.7
05 0 0 4.6
06 0 0 2.3
07 21 0 1.6
08 10 16 -.2
09 10 15 0.0
10 10 13 -.2
11 10 13 -.7
12 0 0 2.3
13 12 150 1.5 0. Medium
14 11 800 0.4 -.4 Medium
15 13 19 0.9 -.6 Medium
16 0 0 0.3 0.1 Medium
17 0 0 -.9 0. Closed
18 0 0 1.9 -.5 Open
19 0 0 0.2 0. Open
20 0 0 2.1 -.3 Open
21 0 0 0.3 -.3 Reload 14
22 15 800 1.2 0. Medium
23 14 10 1.2 0. Reload 19
24 15 11 2.3 -.1 Open
25 0 0 -.2 -.3 Open
26 0 0 0.9 -.4 Open
27 0 0 1.0 -.3 Open
28 0 0 1.4 0. Open
29 0 0 1.25 -.4 Reload 20
30 0 0 1.2 -.3 Open
31 0 0 0.9 -.2 Reload 22
32 0 0 1.2 -.4 Medium
33 13 7 1.7 0.2 Medium (after ECDC)
34 0 0 1.9 0.3 Medium

Details
_______
Entry display output on Thu May 15 16:57:35 2003


----------------------------------------------------------------------------
1030515xxx hutch PHYSICS_OPERATOR May 15 2003 8:56:02:640AM
. . . . . . . . . . . . . . . . . . . .
Load from 10314002 for first shot.
Set density feedback gain to zero.

Load clean
----------------------------------------------------------------------------
1030515003 hutch PHYSICS_OPERATOR May 15 2003 9:15:51:670AM
. . . . . . . . . . . . . . . . . . . .
Plasma. First plasma shot attempt. Full length.
Under preprogrammed gas puff.

Now we switch off commutation and adjust the voltages.
Draw OH1 to +600V.
OH2 to +150V
EF1 to +400V
Each are symmetrically copied into the upper and lower.
Draw EF3 Voltage to +1300V.
Load
----------------------------------------------------------------------------
1030515004 hutch PHYSICS_OPERATOR May 15 2003 9:43:37:696AM
. . . . . . . . . . . . . . . . . . . .
Got a minor flash at 16ms.
Fields show a slowly increasing Br as desired,
but a strong curvature, not desired.

I had forgotten to lower the pressure. We get about
.08 mtorr.

Got a loop voltage of about 5.5V but it ramps up during
the first 10 ms.

Got 600 V out of OH1, 190V OH2U, 230V OH2L. 400V EF2s.

There is a problem with the OH2s going in different directions
later in the shot we probably need to bring the fizzle detector
earlier.


Adjustments:
Fizzle detector OHs to 300ms.
OH1 to 700V
OH2s to 135V
Pulse Gas 4 fill puff to 18ms from 27ms.
Br offset to 1.5mT from 0.5mT.
----------------------------------------------------------------------------
1030515005 hutch PHYSICS_OPERATOR May 15 2003 10:04:51:400AM
. . . . . . . . . . . . . . . . . . . .
No light.

OH1V got 600V.
Still got over 200V on OH2. Seems not to follow
demand. Perhaps an integral feedback issue.
No ratiomatic data.

Adjustments:
Fill puff to 20ms.
Round out the rise of OH2s to prevent saturation.
EF3 V to 1100V.
----------------------------------------------------------------------------
1030515006 hutch PHYSICS_OPERATOR May 15 2003 10:18:49:236AM
. . . . . . . . . . . . . . . . . . . .
No light. Got .057mtorr.

OH2 adjustment was in the right direction but not enough.

Adjustments:
OH2 ramp even slower to prevent saturation.
EF3 voltage to 900V in first 5ms.
----------------------------------------------------------------------------
1030515007 hutch PHYSICS_OPERATOR May 15 2003 10:34:26:540AM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Very late breakdown 20ms but lasts till 45ms.
Bz swings quickly positive and then back down.
It seems that the breakdown occurs on the second minimum.

Adjustments:
Drop the OH2 early points some more.
EF3 first point made into a slow ramp.
----------------------------------------------------------------------------
1030515008 hutch PHYSICS_OPERATOR May 15 2003 10:49:55:093AM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Bdown at 10ms. 15kA current.
This is very promising but the current can't get going because
the Bz is still swinging back negative at the time the plasma
is starting.

EF3 voltage to 1200 at 6ms. Try to remove the Bz dip.
----------------------------------------------------------------------------
1030515009 hutch PHYSICS_OPERATOR May 15 2003 11:07:33:873AM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Almost identical 15kA, slightly faster Halpha rise.

EF3 V to 1500V.
----------------------------------------------------------------------------
1030515010 hutch PHYSICS_OPERATOR May 15 2003 11:24:32:383AM
. . . . . . . . . . . . . . . . . . . .
Fizzle.
Looks as if the first positive swing on Bz is caused by the
EF2 early swing. The negative swing is caused by the OH1 finally
turning on hard at about 7ms.

Lower EF2V point at -10ms.
Raise EF3V to 1600V at 8-12ms. Lower it to 1300V at 20ms.
----------------------------------------------------------------------------
1030515011 hutch PHYSICS_OPERATOR May 15 2003 11:38:58:343AM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Sightly less current. Still not keeping up with
OH1. The EF2 change seemed significant.

Adjustments:
Lower OH1V back to 600V to avoid overdrive.
Make OH2V 120V at 0ms to increase the impulse
EF3V to 1000V at 1ms.
----------------------------------------------------------------------------
1030515012 hutch PHYSICS_OPERATOR May 15 2003 11:55:45:946AM
. . . . . . . . . . . . . . . . . . . .
No light.

Adjustments:
OH2V to 100V at 10ms to remove swing back.
EF2V to -100V from +200V at -5ms.
----------------------------------------------------------------------------
1030515013 hutch PHYSICS_OPERATOR May 15 2003 12:20:31:453PM
. . . . . . . . . . . . . . . . . . . .
Plasma till about 60ms 173kA max.
Dies because of position uncontrol.

Adjustments:
EF2s to -100V at -1ms.
OH2V to 100V at 30ms from 0V.
----------------------------------------------------------------------------
1030515014 hutch PHYSICS_OPERATOR May 15 2003 12:44:57:053PM
. . . . . . . . . . . . . . . . . . . .
Plasma till 2s.
At .1s we get 350kA. Seems like a well controlled shot.


Adjustment:
Br offset to 1mT from 1.5mT
----------------------------------------------------------------------------
1030515015 hutch PHYSICS_OPERATOR May 15 2003 12:56:45:806PM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Slightly later breakdown. Fill was .06: slightly higher.

Br offset to 2mT.
----------------------------------------------------------------------------
1030515016 hutch PHYSICS_OPERATOR May 15 2003 1:10:31:640PM
. . . . . . . . . . . . . . . . . . . .
No light.

Br back to 1.5mT offset
EF1current to -6200 from 6000 (demand) at 0s.
----------------------------------------------------------------------------
1030515017 hutch PHYSICS_OPERATOR May 15 2003 1:23:17:113PM
. . . . . . . . . . . . . . . . . . . .
Fizzle. No current very weak light.
mflux shows I went the wrong way on the EF1 current.
Yes, on second thoughts I did.

Adjustments:
EF2current to -5800
----------------------------------------------------------------------------
1030515018 hutch PHYSICS_OPERATOR May 15 2003 1:36:16:490PM
. . . . . . . . . . . . . . . . . . . .
No light.


EF4 current to -1350 from -1320A.
----------------------------------------------------------------------------
1030515019 hutch PHYSICS_OPERATOR May 15 2003 1:48:59:560PM
. . . . . . . . . . . . . . . . . . . .
No light.
The field null looks fabulous.

Add voltage to EF3 from 3ms to 12ms.
----------------------------------------------------------------------------
1030515020 hutch PHYSICS_OPERATOR May 15 2003 2:03:00:800PM
. . . . . . . . . . . . . . . . . . . .
No light.

Reload shot 14.
----------------------------------------------------------------------------
1030515021 hutch PHYSICS_OPERATOR May 15 2003 2:14:52:566PM
. . . . . . . . . . . . . . . . . . . .
No light.

This seems to show that my duds were not caused by fields.
We seem to be getting a field configuration almost identical
to the shot 14 fields.


Fill puff to 17ms from 20.
----------------------------------------------------------------------------
1030515022 hutch PHYSICS_OPERATOR May 15 2003 2:27:59:710PM
. . . . . . . . . . . . . . . . . . . .
Plasma. lost ratiomatic data.


Load shot 19.
EF4 current to -1330A
----------------------------------------------------------------------------
1030515023 hutch PHYSICS_OPERATOR May 15 2003 2:41:58:890PM
. . . . . . . . . . . . . . . . . . . .
Fizzle. About 10kA of current. This is the wider null case.
This shows that my previous duds were not really a function
of gas or anything obvious. Pressure .061mtorr.


EF4 current to -1340A
EF3 voltage increase at 8ms.
----------------------------------------------------------------------------
1030515024 hutch PHYSICS_OPERATOR May 15 2003 3:04:13:580PM
. . . . . . . . . . . . . . . . . . . .
Fizzle, Breakdown about 15ms. 10kA only.
Bz +2mT. Fill .059mtorr.

EF4 current to -1355 from -1340A.
----------------------------------------------------------------------------
1030515025 hutch PHYSICS_OPERATOR May 15 2003 3:06:10:863PM
. . . . . . . . . . . . . . . . . . . .
Dud. Bz =-.5mT

EF4 current -1345A.
----------------------------------------------------------------------------
1030515026 hutch PHYSICS_OPERATOR May 15 2003 3:19:32:323PM
. . . . . . . . . . . . . . . . . . . .
Dud.

Fill puff to 17ms.
----------------------------------------------------------------------------
1030515027 hutch PHYSICS_OPERATOR May 15 2003 3:32:33:700PM
. . . . . . . . . . . . . . . . . . . .
Dud. Pressure .047mtorr.


Fill puff to 25ms.
----------------------------------------------------------------------------
1030515028 hutch PHYSICS_OPERATOR May 15 2003 3:45:55:863PM
. . . . . . . . . . . . . . . . . . . .
Dud


Load shot 20.
EF4 current to -1365A.
----------------------------------------------------------------------------
1030515029 hutch PHYSICS_OPERATOR May 15 2003 3:59:59:806PM
. . . . . . . . . . . . . . . . . . . .
Dud.

Ef4 to -1375
----------------------------------------------------------------------------
1030515030 hutch PHYSICS_OPERATOR May 15 2003 4:14:12:563PM
. . . . . . . . . . . . . . . . . . . .
Dud.

Load from shot 22.
----------------------------------------------------------------------------
1030515031 hutch PHYSICS_OPERATOR May 15 2003 4:25:39:236PM
. . . . . . . . . . . . . . . . . . . .
Dud.

Fill puff to 22ms.
----------------------------------------------------------------------------
1030515032 hutch PHYSICS_OPERATOR May 15 2003 4:41:38:090PM
. . . . . . . . . . . . . . . . . . . .
Dud.


Do ecdc for 5 minutes.
Fill puff to 20ms.
----------------------------------------------------------------------------
1030515033 hutch PHYSICS_OPERATOR May 15 2003 4:56:47:800PM
. . . . . . . . . . . . . . . . . . . .
Fizzle. 7kA. Bdwn at about 13ms.

No changes.
----------------------------------------------------------------------------
1030515034 hutch PHYSICS_OPERATOR May 15 2003 4:57:09:300PM
. . . . . . . . . . . . . . . . . . . .
Dud.

Session Leader Comments

Physics Operator Comments
May 15 2003 08:56:02:640AMIan HutchinsonLoad from 10314002 for first shot.
Set density feedback gain to zero.

Load clean
May 15 2003 09:15:51:670AM1030515003Ian HutchinsonPlasma. First plasma shot attempt. Full length.
Under preprogrammed gas puff.

Now we switch off commutation and adjust the voltages.
Draw OH1 to +600V.
OH2 to +150V
EF1 to +400V
Each are symmetrically copied into the upper and lower.
Draw EF3 Voltage to +1300V.
Load
May 15 2003 09:43:37:697AM1030515004Ian HutchinsonGot a minor flash at 16ms.
Fields show a slowly increasing Br as desired,
but a strong curvature, not desired.

I had forgotten to lower the pressure. We get about
.08 mtorr.

Got a loop voltage of about 5.5V but it ramps up during
the first 10 ms.

Got 600 V out of OH1, 190V OH2U, 230V OH2L. 400V EF2s.

There is a problem with the OH2s going in different directions
later in the shot we probably need to bring the fizzle detector
earlier.


Adjustments:
Fizzle detector OHs to 300ms.
OH1 to 700V
OH2s to 135V
Pulse Gas 4 fill puff to 18ms from 27ms.
Br offset to 1.5mT from 0.5mT.
May 15 2003 10:04:51:400AM1030515005Ian HutchinsonNo light.

OH1V got 600V.
Still got over 200V on OH2. Seems not to follow
demand. Perhaps an integral feedback issue.
No ratiomatic data.

Adjustments:
Fill puff to 20ms.
Round out the rise of OH2s to prevent saturation.
EF3 V to 1100V.
May 15 2003 10:18:49:237AM1030515006Ian HutchinsonNo light. Got .057mtorr.

OH2 adjustment was in the right direction but not enough.

Adjustments:
OH2 ramp even slower to prevent saturation.
EF3 voltage to 900V in first 5ms.
May 15 2003 10:34:26:540AM1030515007Ian HutchinsonFizzle. Very late breakdown 20ms but lasts till 45ms.
Bz swings quickly positive and then back down.
It seems that the breakdown occurs on the second minimum.

Adjustments:
Drop the OH2 early points some more.
EF3 first point made into a slow ramp.
May 15 2003 10:49:55:093AM1030515008Ian HutchinsonFizzle. Bdown at 10ms. 15kA current.
This is very promising but the current can't get going because
the Bz is still swinging back negative at the time the plasma
is starting.

EF3 voltage to 1200 at 6ms. Try to remove the Bz dip.
May 15 2003 11:07:33:873AM1030515009Ian HutchinsonFizzle. Almost identical 15kA, slightly faster Halpha rise.

EF3 V to 1500V.
May 15 2003 11:24:32:383AM1030515010Ian HutchinsonFizzle.
Looks as if the first positive swing on Bz is caused by the
EF2 early swing. The negative swing is caused by the OH1 finally
turning on hard at about 7ms.

Lower EF2V point at -10ms.
Raise EF3V to 1600V at 8-12ms. Lower it to 1300V at 20ms.
May 15 2003 11:38:58:343AM1030515011Ian HutchinsonFizzle. Sightly less current. Still not keeping up with
OH1. The EF2 change seemed significant.

Adjustments:
Lower OH1V back to 600V to avoid overdrive.
Make OH2V 120V at 0ms to increase the impulse
EF3V to 1000V at 1ms.
May 15 2003 11:55:45:947AM1030515012Ian HutchinsonNo light.

Adjustments:
OH2V to 100V at 10ms to remove swing back.
EF2V to -100V from +200V at -5ms.
May 15 2003 12:20:31:453PM1030515013Ian HutchinsonPlasma till about 60ms 173kA max.
Dies because of position uncontrol.

Adjustments:
EF2s to -100V at -1ms.
OH2V to 100V at 30ms from 0V.
May 15 2003 12:44:57:053PM1030515014Ian HutchinsonPlasma till 2s.
At .1s we get 350kA. Seems like a well controlled shot.


Adjustment:
Br offset to 1mT from 1.5mT
May 15 2003 12:56:45:807PM1030515015Ian HutchinsonFizzle. Slightly later breakdown. Fill was .06: slightly higher.

Br offset to 2mT.
May 15 2003 01:10:31:640PM1030515016Ian HutchinsonNo light.

Br back to 1.5mT offset
EF1current to -6200 from 6000 (demand) at 0s.
May 15 2003 01:23:17:113PM1030515017Ian HutchinsonFizzle. No current very weak light.
mflux shows I went the wrong way on the EF1 current.
Yes, on second thoughts I did.

Adjustments:
EF2current to -5800
May 15 2003 01:36:16:490PM1030515018Ian HutchinsonNo light.


EF4 current to -1350 from -1320A.
May 15 2003 01:48:59:560PM1030515019Ian HutchinsonNo light.
The field null looks fabulous.

Add voltage to EF3 from 3ms to 12ms.
May 15 2003 02:03:00:800PM1030515020Ian HutchinsonNo light.

Reload shot 14.
May 15 2003 02:14:52:567PM1030515021Ian HutchinsonNo light.

This seems to show that my duds were not caused by fields.
We seem to be getting a field configuration almost identical
to the shot 14 fields.


Fill puff to 17ms from 20.
May 15 2003 02:27:59:710PM1030515022Ian HutchinsonPlasma. lost ratiomatic data.


Load shot 19.
EF4 current to -1330A
May 15 2003 02:41:58:890PM1030515023Ian HutchinsonFizzle. About 10kA of current. This is the wider null case.
This shows that my previous duds were not really a function
of gas or anything obvious. Pressure .061mtorr.


EF4 current to -1340A
EF3 voltage increase at 8ms.
May 15 2003 03:04:13:580PM1030515024Ian HutchinsonFizzle, Breakdown about 15ms. 10kA only.
Bz +2mT. Fill .059mtorr.

EF4 current to -1355 from -1340A.
May 15 2003 03:06:10:863PM1030515025Ian HutchinsonDud. Bz =-.5mT

EF4 current -1345A.
May 15 2003 03:19:32:323PM1030515026Ian HutchinsonDud.

Fill puff to 17ms.
May 15 2003 03:32:33:700PM1030515027Ian HutchinsonDud. Pressure .047mtorr.


Fill puff to 25ms.
May 15 2003 03:45:55:863PM1030515028Ian HutchinsonDud


Load shot 20.
EF4 current to -1365A.
May 15 2003 03:59:59:807PM1030515029Ian HutchinsonDud.

Ef4 to -1375
May 15 2003 04:14:12:563PM1030515030Ian HutchinsonDud.

Load from shot 22.
May 15 2003 04:25:39:237PM1030515031Ian HutchinsonDud.

Fill puff to 22ms.
May 15 2003 04:41:38:090PM1030515032Ian HutchinsonDud.


Do ecdc for 5 minutes.
Fill puff to 20ms.
May 15 2003 04:56:47:800PM1030515033Ian HutchinsonFizzle. 7kA. Bdwn at about 13ms.

No changes.
May 15 2003 04:57:09:300PM1030515034Ian HutchinsonDud.

Engineering Operator Comments
ShotTimeTypeStatusComment
108:04:38:187AMTestOkCycle Test
208:14:27:920AMTestOkCycle Test
309:03:51:840AMPlasmaOk
409:17:11:190AMPlasmaOk
509:41:20:647AMPlasmaOk
610:02:39:820AMPlasmaOk
710:16:58:123AMPlasmaOk
810:32:24:867AMPlasmaOk
910:47:41:810AMPlasmaOk
1011:05:33:353AMPlasmaOk
1111:23:26:787AMPlasmaOk
1211:37:00:560AMPlasmaOk
1311:53:41:583AMPlasmaOk
1412:18:16:420PMPlasmaOk
1512:41:43:813PMPlasmaOk
1612:54:37:427PMPlasmaOk
1701:08:34:387PMPlasmaOk
1801:21:27:030PMPlasmaOk
1901:34:17:600PMPlasmaOk
2001:47:02:477PMPlasmaOk
2101:59:41:560PMPlasmaOk
2202:12:52:360PMPlasmaOk
2302:26:05:617PMPlasmaOk
2402:38:40:760PMPlasmaOk
2502:51:19:140PMPlasmaOk
2603:04:27:860PMPlasmaOk
2703:17:30:350PMPlasmaOk
2803:30:40:933PMPlasmaOk
2903:43:29:640PMPlasmaOk
3003:56:20:803PMPlasmaOk
3104:11:05:010PMPlasmaOk
3204:23:43:220PMPlasmaOk
3304:42:10:560PMPlasmaOk
3404:54:44:500PMPlasmaOk