Alcator C-Mod Run 1020607 Information

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Miniproposals
Miniproposal:298a
Date Filed: 5/20/2002
Title:C-Mod Plasma Startup
First Author:Jim Irby
Session Leader:Jim Irby (shots 1-16)

Operators
Session leader(s):Jim Irby
Physics operator(s):Bill Rowan
Engineering operator(s):Gary Dekow,Bill Cochran

Engineering Operator Run Comment
Plasma Startup (298a); SL:Irby; PO:Rowan,EO: Cochran/Dekow

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:28:790PM
Author: To Be Determined
Run Summary for Run 1020607 Plasma Startup (298a)

SL:Irby
PO:Rowan
EO: Cochran/Dekow

Overnight ECDC in D2 at 2e-4 Torr stopped at 07:00

Startup was from 1010801015; an 800 kA shot

Results:

Our first fizzle since August 2001 was obtained on shot
2 today. Tweaks of Br0 and Bz0 continued until shot 16 when a
530 kA, 122 ms, discharge was produced following final tweaks in
gas and Bz0. Shot 15 was probably terminated early by too much gas.
The CII signal was relatively low for this early in the campaign.
ECDC was run between many shots and may have helped somewhat to keep
the fizzle rate up. Wall conditioning will continue all next week.
A great deal of the run day was lost because of a CAMAC
problem on server 2. The problem was eventually traced to a broken
fiber from the Magnetics rack.
An oscillation in EF2L, that made it difficult to control
Br0, was fixed late in the run while the broken fiber was being
tracked down. Boards and plugs were reseated, and several suspect
ICs were replaced.

Physics Operator Summaries
Entered: Jul 7 2004 04:37:14:833PM
Author: To Be Determined
Physop Summary for 1020607
SL:Irby
PO:Rowan
EO: Cochran/Dekow

ENGINEERING SETUP FOR 1020607

Overnight ECDC in D2 at 2e-4 Torr, stopping at 07:00

Power systems the same as for shot 1010801015

c-side and b-top gas should be as on run 1020606

RUN PLAN
First attempt at obtaining plasmas following an extended down time.

Overnight ECDC in D2 at 2e-4 Torr, stopping at 07:00
Startup from 1010801015; an 800 kA shot
We will want between shot ecdc in D2
We should try to have the following diagnostics if at all
possible:
. TCI
. Video view from A-Hor (or new F-Hor if possible)
. G-side ratiomatic
. single chord VB
. CII, or H-alpha, or some othe photon...

RUN SUMMARY
One plasma (disruption at 120 ms) was made during this run, 016.
The remainder of the shots were fizzles and duds.

Prior to the first shot, the density demand was set to 0 since a
feedback signal was not expected. Specifically, NL_04 was set to
0 in segment 2 because a TCI channel was not available. On the
previous day's operation, the operator changed IC_EF4 from -1305
(the value for the model shot 101080105) to -1250 to correct BZ_0.
This same change was used to start the run today.

For earlier shots in this run, it was not possible to adjust
BR_0 because it was oscillating -- apparently due to a power
supply oscillation which was remedied in the course of the run.

There were some CAMAC problems similar to those experienced
at the end of the last campaign: hangs during the init state.
These were removed by turning off unneeded modules (XTOMO) and
by repairing connectors/cables (MAGNETICS).

In the course of the run, the DNB was fired in synchronization
with the C-Mod shots. These shots would have been fired into
plasma but for the short duration of the C-Mod shots. The MSE
system detected the emission due to the interaction of the beam
with the background neutral gas.

SCORECARD

Plasmas 0
Disruptions 1
Fizzles 6
Duds 6
No power 3

Total 16

Session Leader Comments
Jun 7 2002 09:33:42:480AM1020607002Jim Irbyflash on h-alpha, cii, and c-port tv.
Jun 7 2002 11:49:32:657AM1020607009Jim IrbyStill having problems with EF2L that may be affecting
startup ---- stopping for a while for Bill and Gary to
debug
Jun 7 2002 12:56:57:647PM1020607011Jim IrbyBill and Gary spent some time looks at EF2 supply. Nothing
found, but they reseated and cleaned some components.


Jun 7 2002 04:35:36:513PM1020607013Jim IrbyEF2L supply is fixed

Dud. Bz0 high.
Jun 7 2002 05:16:24:187PM1020607016Jim IrbyPlasma: 530kA, 122 ms

Physics Operator Comments
Jun 7 2002 08:03:29:340AMBill RowanRun Plan for run 1020607 Plasma Startup (298a)
SL:Irby
PO:Rowan
EO: Cochran/Dekow

Overnight ECDC in D2 at 2e-4 Torr, stopping at 07:00

Startup from 1010801015; an 800 kA shot

We will want between shot ecdc in D2

c-side and b-top gas should be as on run 1020606

We should try to have the following diagnostics if at all
possible:
. TCI
. Video view from A-Hor (or new F-Hor if possible)
. G-side ratiomatic
. single chord VB
. CII, or H-alpha, or some othe photon...


Expect a delay in start of operations this morning for magnetics repair.
Jun 7 2002 08:45:52:593AMBill RowanStarted pcs

There will be no density feedback today.
Set the feedback to 0 after 100 ms.
Jun 7 2002 08:56:59:250AMBill Rowan
Changed IC_EF4 from -1305 to -1250. Note BZ_0 for the last shot 023 from yesterday.
Jun 7 2002 09:10:33:897AM1020607001Bill Rowan001. No power
Jun 7 2002 09:29:03:113AM1020607002Bill Rowan002. Signal on H-alpha and CII. No current rise.

For the next shot: Change IC_EF4 from -1250 to -1200.
Jun 7 2002 09:46:32:043AM1020607003Bill Rowan003. Dud. ECDC before this shot.

Jun 7 2002 09:55:40:997AM1020607003Bill Rowan
Next shot. No ECDC before the next shot.
Reduced BR_0 by 1 mT
Jun 7 2002 10:10:47:080AM1020607004Bill Rowan004. Fizzle.

Next shot. No ECDC
Lowered BR_0 by 0.75 mT
Increased IC_EF4 from -1200 to -1190
Jun 7 2002 10:27:23:733AM1020607005Bill Rowan005. Dud.

Next shot. No ECDC
Increased IC_EF4 from -1190 to -1180
Jun 7 2002 10:43:13:147AM1020607006Bill Rowan006. Dud

Next shot. ECDC before the shot
Increased IC_EF4 from -1180 to -1170
Jun 7 2002 11:06:49:573AM1020607007Bill Rowan007. Dud.

Next shot. ECDC before shot.
Changed BR_0 to increase by 2 mT
Jun 7 2002 11:23:59:913AM1020607008Bill Rowan008. Fizzle.

Next shot. ECDC before this shot.
Jun 7 2002 11:46:15:197AM1020607009Bill Rowan009. Fizzle

Next shot. ECDC before this shot.
Jun 7 2002 12:03:39:613PM1020607010Bill Rowan010. Dud.

No changes before the next shot.
Jun 7 2002 12:57:55:507PM1020607011Bill Rowan011. No power.
CAMAC server is down
Jun 7 2002 04:43:02:603PM1020607013Bill Rowan013. Dud

Next shot. IC_EF4 from -1170 to -1180
Add 1 ms to the gas prepuff
Jun 7 2002 04:51:31:193PM1020607014Bill Rowan014. Fizzle

Next shot. Add 2 ms to gas prepuff
Jun 7 2002 05:10:26:960PM1020607015Ian HutchinsonRan user10/hutch/mds/predictors/load_predictors.pro

This is, I think, supposed to update all the coefficients in the analysis fluxihh tree.
It was up till now using the f24A flux loop. After shot 15 it will use f24.
Looking in a traverser, the loop is really changed.
Jun 7 2002 05:19:08:377PM1020607016Bill Rowan016. Plasma, 120 ms. 0.5 MA Large carbon puff at theend of the shot.

Engineering Operator Comments
ShotTimeTypeStatusComment
109:06:08:390AMPlasmaBadEF1 Commutation Supply was off
209:18:54:377AMPlasmaOk
309:40:44:257AMPlasmaOk
409:57:53:687AMPlasmaOk
510:13:43:570AMPlasmaOk
610:30:39:957AMPlasmaOk
710:54:14:273AMPlasmaOk
811:14:46:680AMPlasmaOk
911:37:18:683AMPlasmaOk
1011:56:57:430AMPlasmaOk
1112:52:56:483PMPlasmaBadCamac2_Server went down during init
1204:13:23:993PMPlasmaBadCamac Problems
1304:28:14:207PMPlasmaOk
1404:43:40:200PMPlasmaOk
1504:56:40:127PMPlasmaOk
1605:09:42:410PMPlasmaOk