Alcator C-Mod Run 1031015 Information

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Miniproposals
Miniproposal:
Date Filed:
Title:
First Author:
Session Leader: Unknown (shots 1-27)

Operators
Session leader(s): Unknown
Physics operator(s):Jim Irby
Engineering operator(s):Gary Dekow,Bill Parkin,Ed Fitzgerald

Engineering Operator Run Comment
Plasma startup and conditioning PO: Irby; EO: Dekow/Fitz/Parkin

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Physics Operator Summaries
Entered: Jul 7 2004 04:37:19:147PM
Author: Jim Irby
Plasma Conditioning Run


EO: Dekow, Fitzgerald, Parkin
PO: Irby


Summary
-------

We began with a cycle test to check the gas puff and data system. The
first plasma attempt was successful producing a 1 s long upper null
discharge. Injections were seen on the 2Pi diode, but the H/(H+D) was
low (6%). The h/d came up, as usual, as the day continued. We had a
few full length plasmas, but we were also in the plasma/fizzle mode of
operation most of the day. Only a couple of the upper null discharges
ran without an early MARFE, though it appeared to be improving
throughout the day.

On shot 22 we went back to lower null operation by loading shot
1031010007 and raising the density to 1e20/m^2 and the plasma current
to 800 kA. This shot ran well, but the following shot had an early
density rise with gas supplied by something other than the gas valve.
The density, h_alpha, and CII signals all had very large oscillations
on them. We did not make another good plasma after this shot.

H/(H+D) drifted around 12 to 15% most of the day.

Bruce closed the pumping stack gatevalves right before the shot on a
couple of shots for up to 10 minutes. Using the new script written by
Josh, he was able to store away pressure data during this entire time.
Pressure continued to rise.

The NSTX X-Ray diagnostic with the new upgrades is working well.

for phyops: There was a lot of drift in Bz0 today, which may have been
some of the explanation for the large number of fizzles.

Score
-----

Duds 17
Fizzles 03,07,09,11,12,13,15,20,21,24,25,27
Plasmas 02,04,05,06,08,10,14,16,18,19,22,23,26
Test shots 01

Session Leader Comments

Physics Operator Comments
Oct 15 2003 07:55:19:863AMJim IrbyEngineering setup for Wednesday, 15 Oct 2003

Purpose: Plasma startup and conditioning

Session leader: --
Physics operator: Irby
Engineering operator:

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

Run begins at 09:00 and ends at 17:00.

Power systems the same as on 1031010023 (0.8 MA, upper null)

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)

Enable the following gate valves: ECE, VUV, DNB

-----------------------------------------------------------------------
RF Setup: Transmitters 1,2,3, and 4 in RUN ON by 08:00 am

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

RF Group will continue conditioning.

-------------------------------------------------------------------------------
Oct 15 2003 08:48:19:683AMJim IrbyLoaded from 1031010023 (both seg 1 and seg 2)

C-Hor gatevalve has been opened for NSTX X-Ray Diagnostic

Oct 15 2003 08:58:10:647AM1031015001Jim IrbyCycle test --- check out data system and check gas puff level

Gas low at t=0


Time (ms): 0 5 10 25
----------------------------------------
Ip (kA): -3.2730 -2.2774 -2.9363 -2.2738
dIp/dt (kA/ms): 0.1290 0.0485 -0.1293 -0.1130
pressure (mTorr): 0.0381 0.0381 0.0386 0.0390
Bz0 (mT): -0.0677 0.0391 0.1320 0.1736
Br0 (mT): 0.0432 -0.0258 -0.0389 -0.0021


Oct 15 2003 09:26:11:470AM1031015002Jim IrbyIncreased gas puff from 20 to 24 ms

Plasma for 1 s --- gas puff about right

Looks like Marfing on CII signal --- multiple low level injections on 2PI diode

Good upper null discharge

H/D around 6%
Oct 15 2003 09:41:53:877AM1031015003Jim IrbyPCS Repeat

Fizzle

Time (ms): 0 5 10 25
----------------------------------------
Ip (kA): -3.6874 -20.6574 -31.4072 -32.7286
dIp/dt (kA/ms): -1.5361 -2.7810 -1.9316 1.0868
pressure (mTorr): 0.0591 0.0585 0.0591 0.0494
Bz0 (mT): -3.8817 -1.2441 3.3343 21.9400
Br0 (mT): -0.9635 -1.2763 -1.6703 -1.3476

Everything looks fine.
Oct 15 2003 09:56:33:190AM1031015004Jim IrbyNo PCS changes

Plasma for 1 s, a little longer than 002 --- CII radiation factor of two higher during MARFE
than on shot 002

Fewer injections seen on 2Pi diode

H/(H+D) about 9% --- up from shot 002

Vessel pressure still high after 14 minutes ---- 1.4e-6 --- warming something up




Oct 15 2003 10:19:39:880AM1031015005Jim IrbyDropped density request starting at approx 0.4 s
Reduced gas puff by 2 ms

Plasma into rampdown

H/D up a little but also lower density

Some rf power from D and E

Oct 15 2003 10:51:04:023AM1031015006Jim IrbyAdded 1 ms to the puff

Waited until IGT was 1e-6 Torr to enter INIT --- took 26 minutes or so

Plasma for 1.08 s

H/(H+D) at 11%

A little less gas was needed and CII signal down somewhat during MARFE



Oct 15 2003 11:12:05:390AM1031015007Jim IrbyPCS repeat

waited 26 minutes again --- IGT at 1.3e-6 Torr when we entered INIT

Fizzle

Small drift upward in Bz0, pressure identical to shot 6

Oct 15 2003 11:38:31:933AM1031015008Jim IrbyEF4 from -1310 to -1330

Plasma into rampdown

very bad TCI subtraction?

Density lower after 0.4 s than on shot 6

MARFE delayed as determined from CII signal

H/(H+D) 15% at 0.8 s

Oct 15 2003 11:49:40:163AM1031015009Jim IrbyFizzle --- started init at 2e-6 Torr --- gas pressure a little high at t=0

Oct 15 2003 12:17:10:827PM1031015010Jim IrbyNo PCS changes --- pressure 1.2e-6 Torr at INIT

Plasma for 1.05 s

CII back up

No increase in H/(H+D) compared to shot 8

Oct 15 2003 12:32:38:813PM1031015011Jim IrbyNo PCS changes

Long wait to clear cell for entry --- about 28 minutes total --- 1.0e-6 Torr at INIT

Fizzle ---

Note the Brian just ran his gauge calibration program and g-side pressures went from
0.059 to 0.092 mTorr.

Bz0 has now drifted back down.
Oct 15 2003 12:40:41:190PM1031015012Jim IrbyEF4 back to -1310 from -1330

Fizzle

gas a little high
Oct 15 2003 12:54:14:163PM1031015013Jim IrbyGas puff reduced by 2 ms to 21 ms

EF4 back to -1330

Fizzle --- Bz0 still too high!

Time (ms): 0 5 10 25
----------------------------------------
Ip (kA): -4.6650 -19.6690 -33.0185 -31.0777
dIp/dt (kA/ms): -1.6318 -2.9232 -2.7146 1.4064
pressure (mTorr): 0.0898 0.0868 0.0878 0.0709
Bz0 (mT): -3.0865 -0.2356 3.5351 19.5497
Br0 (mT): -1.0145 -1.1514 -1.2122 -1.2967

Oct 15 2003 01:28:45:160PM1031015014Jim IrbyEF4 to -1350 from -1330

Plasma into rampdown

CII much reduced (no MARFE?)

H/(H+D) down a % or two.


Oct 15 2003 01:33:19:523PM1031015015Jim IrbyFizzle

Bz0 drifted again

Oct 15 2003 02:00:26:410PM1031015016Jim IrbyReduced clearin by .005 m (Blip request)

EF4 from -1350 to -1330 (again)

Plasma well into rampdown

We got requested inner gap change

H/(H+D) higher than shot 14
Oct 15 2003 02:12:14:483PM1031015017Jim IrbyDud --- pressure okay, but another Bz0 shift
Oct 15 2003 02:34:59:220PM1031015018Jim IrbyEF4 to -1360

Plasma into rampdown

H/(H+D) down a couple of % relative to shot 16

1 MW each from D & E

Oct 15 2003 02:57:34:457PM1031015019Jim IrbyIncreased gas puff by 1 ms

Plasma into rampdown

H/d overlay of shot 18

Clean 1.3 MW out of E, .9 MW of of D with interrupts

Oct 15 2003 03:04:18:443PM1031015020Jim IrbyEF4 from -1360 to -1350

Fizzle --- Bz0 still pretty negative, gas looked okay
Oct 15 2003 03:24:28:873PM1031015021Jim IrbyEF4 to -1330

DNB will be fired into plasma at 0.9 s

Fizzle --- high Bz0

Oct 15 2003 04:00:16:603PM1031015022Jim IrbyEF4 to -1350 again!

Loaded shot 1031010007 (lower null, 600 kA, 5e19) into seg 2
Adjusted Ip to 800kA
Raised density to 1e20.

asked to enable gv1 and gv2 closure after the shot (for 10 minutes)

Plasma for 1.609 s

H/(H+D) 13% at 0.8 s

Oct 15 2003 04:23:09:260PM1031015023Jim IrbyReduced clearin by .005 m


Plasma for 1.45 s

Lots of sawteeth

Oct 15 2003 04:28:55:720PM1031015024Jim IrbyAdded 1 ms to gas puff


Fizzle

Br0 a little high
Oct 15 2003 04:44:50:017PM1031015025Jim IrbyBr0 from .0005 to .00025

Added another ms to gas puff --- now 24 ms

60 kA fizzle --- lost it / bounced at 20 ms

Oct 15 2003 05:05:52:367PM1031015026Jim IrbyNo PCS changes

Plasma for 0.48 s

Plasma moved to upper chamber (MARFE?)

Engineering Operator Comments
ShotTimeTypeStatusComment
108:48:45:057AMTestOkdata system test
209:04:58:807AMPlasmaOk
309:26:52:110AMPlasmaOk
409:39:48:850AMPlasmaOk
510:03:19:723AMPlasmaOk
610:33:27:993AMPlasmaOk
711:02:45:847AMPlasmaOk
811:16:28:693AMPlasmaOk
911:34:06:990AMPlasmaOk
1011:50:37:380AMPlasmaOk
1112:21:40:460PMPlasmaOk
1212:36:43:383PMPlasmaOk
1312:49:31:657PMPlasmaOk
1401:03:07:350PMPlasmaOk
1501:20:21:410PMPlasmaOk
1601:39:04:657PMPlasmaOk
1701:57:53:023PMPlasmaOk
1802:17:12:940PMPlasmaOk
1902:43:03:657PMPlasmaOk
2003:00:54:607PMPlasmaOk
2103:14:10:097PMPlasmaOk
2203:37:36:867PMPlasmaOk
2304:02:18:317PMPlasmaOk
2404:20:50:437PMPlasmaOk
2504:34:05:113PMPlasmaOk
2604:47:29:557PMPlasmaBadPF breaker opeduring shot
2705:04:33:883PMPlasmaOk