Alcator C-Mod Run 1020716 Information

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Miniproposals
Miniproposal:
Date Filed:
Title:
First Author:
Session Leader:Jim Irby (shots 1-19)

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

Engineering Operator Run Comment
Boronization Recovery & RF Conditioning; SL: Irby; PO: Mossessian; EO:De

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:29:397PM
Author: To Be Determined
Run Summary for 1020716: Boronization Recovery and Rf Conditioning

EO: Dekow/Cochran
PO: Mossessian
SL: Irby


The startup reliability was poor today, almost certainly because of the
boronization. As Steve Wolfe pointed out, gas from the walls is raising
the gas pressure very quickly and ruining the startup. We were also
unable to control the density at the 6e19/m^2 level we obtained easily
last Friday. However, the few shots we did get indicated that the
boronization has done a very good job of reducing the H/(H+D) from
8-10% down to 3-5%.

ed that the
boronization has done a very good job of reducing the H/(H+D) from
8-10% down to 3-5%. The radiated power as measured by the 2Pi diode
SL: Irby


The startup reliability was poor today, almost certainly because of the
boronization. As Steve Wolfe pointed out, gas from the walls is raising
the gas pressure very quickly and ruining the startup. We were also
unable to control the density at the 6e19/m^2 level we obtained easily
last Friday. However, the few shots we did get indicated that the
boronization has done a very good job of reducing the H/(H+D) from
8-10% down to 3-5%.

ed that the
boronization has done a very good job of reducing the H/(H+D) from
8-10% down to 3-5%. The radiated power as measured by the 2Pi diode
SL: Irby


The startup reliability was poor today, almost certainly because of the
boronization. As Steve Wolfe pointed out, gas from the walls is raising
the gas pressure very quickly and ruining the startup. We were also
unable to control the density at the 6e19/m^2 level we obtained easily
last Friday. However, the few shots we did get indicated that the
boronization has done a very good job of reducing the H/(H+D) from
8-10% down to 3-5%. The latest plots of H/(H+D) can be seen at

http://www.psfc.mit.edu/people/irby/htod0716.pdf

The radiated power as measured by the 2Pi diode was also down considerably;
about a factor 2.4.

Unfortunately, the boronization also ruined the rf antenna conditioning.
So vacuum conditioning will be required again to get them going for
tomorrow morning.

The first two shots of the day were no power cycle tests to check out
the new ratiomatic controller at g-side, and to verify that the
pressure from the pre-puff was similar to shot 18 from last Friday.
The new controller is working well (though with a minor restart
problem) and the calibration was correct.

On shots 04 and 05 we had no OH1 because of a timer reset problem.
Shot 06 was a no power test of the OH1 timer.
Shot 08 had no EF4 --- enable had been toggled off by accident

We lost 2:45 hours between shot 9 and 10 fixing a problem with the
cryo system.

Duds
Fizzles 03,07,10,11,14,16,18,19
Plasmas 09,12,13,15,17
Eng Faults 04,05,08
Tests 01,02,06

Physics Operator Summaries
Entered: Jul 7 2004 04:37:15:317PM
Author: To Be Determined
Physop summary for run of Tuesday, July 16

Goal - post boronization recovery and RF conditionning

SL Irby
PO Mossessian

Summary:

Notwithstanding several power supply and cooling problems (see SL logbook entries)
we had a few good plasmas. Generally, the startup was not very reliable, as expected after
boronization, but we managed to obtain a series of alternating plasma/fizzle discharges
without changing the startup traces - time histories of Bz, BR, and Ip were virtually
indistinguishable in good plasmas and fizzles.

We had total of 19 shots, among which:

4 tests
3 power supplies failures
8 fizzles
4 plasmas

Details follow:


----------------------------------------------------------------------------
1020716003 mossessian PHYSICS_OPERATOR Jul 16 2002 9:13:55:290AM
. . . . . . . . . . . . . . . . . . . .
9:10

Loaded 1020712018. Coldstart OK

First two shots were no power tests.

Goal - post boronization recovery and RF conditionning
-----------------------------------------------------------------------------
1020716003 mossessian PHYSICS_OPERATOR Jul 16 2002 9:25:37:496AM
. . . . . . . . . . . . . . . . . . . .
Fizzle.

Next shot - try to play with Bz: IC_EF4 -1320 -> -1310
-----------------------------------------------------------------------------
1020716004 mossessian PHYSICS_OPERATOR Jul 16 2002 9:49:08:193AM
. . . . . . . . . . . . . . . . . . . .
No plasma. OH1 problems.

Next shot - no changes
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1020716005 mossessian PHYSICS_OPERATOR Jul 16 2002 10:05:26:243AM
. . . . . . . . . . . . . . . . . . . .
No plasma. OH1 problems again

Diagnosed a timer problem.
Next shot - no power test.
-----------------------------------------------------------------------------
1020716006 mossessian PHYSICS_OPERATOR Jul 16 2002 10:15:10:993AM
. . . . . . . . . . . . . . . . . . . .
OH test looks OK now.
Try for plasma shot
-----------------------------------------------------------------------------
1020716007 mossessian PHYSICS_OPERATOR Jul 16 2002 10:46:11:590AM
. . . . . . . . . . . . . . . . . . . .
Fizzle

Next shot - Bz down -1310 -> -1320, gas down 23 ms -> 21 ms
-----------------------------------------------------------------------------
1020716008 mossessian PHYSICS_OPERATOR Jul 16 2002 1:59:27:013PM
. . . . . . . . . . . . . . . . . . . .
No plasma. No EF4
-----------------------------------------------------------------------------
1020716009 mossessian PHYSICS_OPERATOR Jul 16 2002 2:00:02:013PM
. . . . . . . . . . . . . . . . . . . .
Plasma

Next shot - no changes
-----------------------------------------------------------------------------
1020716010 mossessian PHYSICS_OPERATOR Jul 16 2002 2:01:02:170PM
. . . . . . . . . . . . . . . . . . . .
Fizzle.

Bz drifted down.

For next shot IC_EF4 -1320 -> -1310
-----------------------------------------------------------------------------
1020716011 mossessian PHYSICS_OPERATOR Jul 16 2002 2:25:37:380PM
. . . . . . . . . . . . . . . . . . . .
Fizzle.

Bz a little too high, Br a little too low.

For next shot - drop Bz -1310 -> -1320, Br up 0.5 (offset 0.001 -> 0.0015) mT, gas down 21 -> 20 ms
-----------------------------------------------------------------------------
1020716013 mossessian PHYSICS_OPERATOR Jul 16 2002 3:02:29:530PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

For next shot - target density to 1e20
-----------------------------------------------------------------------------
1020716014 mossessian PHYSICS_OPERATOR Jul 16 2002 3:23:27:026PM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Bz jumped up.

Next shot - no changes
-----------------------------------------------------------------------------
1020716015 mossessian PHYSICS_OPERATOR Jul 16 2002 4:04:21:213PM
. . . . . . . . . . . . . . . . . . . .
PLasma

Next shot - no changes
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1020716016 mossessian PHYSICS_OPERATOR Jul 16 2002 4:04:39:933PM
. . . . . . . . . . . . . . . . . . . .
Fizzle

Next shot - no changes
-----------------------------------------------------------------------------
1020716017 mossessian PHYSICS_OPERATOR Jul 16 2002 4:23:05:710PM
. . . . . . . . . . . . . . . . . . . .
Plasma

Next shot - no changes
-----------------------------------------------------------------------------
1020716018 mossessian PHYSICS_OPERATOR Jul 16 2002 5:03:31:743PM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Bz, Br and ip traces are virtually indistinguishable from shot 17 (plasma) untill current starts going down.
Therefore:
Next shot - no changes
-----------------------------------------------------------------------------
1020716019 mossessian PHYSICS_OPERATOR Jul 16 2002 5:04:16:836PM
. . . . . . . . . . . . . . . . . . . .
Fizzle

Last shot


Session Leader Comments
Jul 16 2002 08:22:08:647AM1020716001Jim IrbyTest shot to see if data system is okay, and check pressure calibration on
new ratiomatic at g-side. New controller was not on. Next shot...
Jul 16 2002 08:23:09:837AM1020716002Jim IrbyCalibration for G-side looks good: With setup from 1020712018 we got a very similar prepuff.
Jul 16 2002 09:24:13:930AM1020716003Jim IrbyFizzle at 45 kA

CII very low at .001

Bz0 may be a little too negative
Jul 16 2002 09:49:10:460AM1020716004Jim IrbyDmitri adjusted EF4 +10 amps

Dud --------- no OH1??



Jul 16 2002 10:22:19:450AM1020716005Jim IrbyTry again.

No OH1 again... Debug time

Power systems group finds an OH1 timer that was hung

Jul 16 2002 10:57:41:640AM1020716008Jim IrbyNo EF4??

Jul 16 2002 12:53:40:433PM1020716009Jim IrbyNo ECDC before shot

Terminated hard X-ray detector with 1k. Still going directly into camac.

Adjusted CO2 laser PZT to avoid having a reset (from 120 to 682 volts)

Trying for plasma again

Plasma for 1.94 s

Still very low CII

H/D 4.2% ---- it's good to boronize

Hard x-ray signal looks much better with 1k term --- very little offset --- much cleaner signal

2PI diode signal down a factor of two or three
Jul 16 2002 02:19:53:013PM1020716010Jim IrbyWe had to delay the run to fix the CRYO system PLC --- the sump was filled about 15" higher than it
should have been when the we lost the common to the PLC module.

2 hours 40 minutes later we try for plasma:

No ECDC
Fizzle
CII up to .002
Jul 16 2002 02:25:47:320PM1020716011Jim IrbyFizzle --- but barely

CII very low, but also very low NL04.

Bz0 +.5 mT

Jul 16 2002 02:59:34:230PM1020716012Jim Irby5 minutes of ECDC

Plasma into rampdown
CII very low

H/D 4.7% at 1 s


Jul 16 2002 03:27:32:190PM1020716013Jim Irby5 minutes of ECDC before shot

Plasma to rampdown

H/D 3% at 1s but signal level is low: variation 3 to 5% during flattop
The next shot we will up the density request to 1.e20/m^2 to improve signal level
and check scaling with density

Note that NL04 is still exceeding the request of 6e19/m^2

Beginning to see some power out of 1,3, and 4...
Jul 16 2002 03:27:58:940PM1020716014Jim Irby5 minutes of ECDC before shot

Density request to 1.e20 /m^2

Fizzle --- no clear reason
Jul 16 2002 04:02:41:087PM1020716015Jim Irby5 minutes of ECDC

Plasma into rampdown
Got density request of 1e20/m^2

H/D 2.5 to 3.5% --- still low signal level --- a good thing I guess

Jul 16 2002 04:28:04:017PM1020716016Jim IrbyFizzle
Jul 16 2002 05:49:24:470PM1020716017Jim IrbyPlasma into rampdown

H/D 3% to 4%

Jul 16 2002 05:49:42:377PM1020716018Jim IrbyFizzle
Jul 16 2002 05:49:55:890PM1020716019Jim IrbyFizzle

Physics Operator Comments
Jul 16 2002 09:13:55:290AM1020716003Dmitri Mossessian9:10

Loaded 1020712018. Coldstart OK

First two shots were no power tests.

Goal - post boronization recovery and RF conditionning
Jul 16 2002 09:25:37:497AM1020716003Dmitri MossessianFizzle.

Next shot - try to play with Bz: IC_EF4 -1320 -> -1310
Jul 16 2002 09:49:08:193AM1020716004Dmitri MossessianNo plasma. OH1 problems.

Next shot - no changes
Jul 16 2002 10:05:26:243AM1020716005Dmitri MossessianNo plasma. OH1 problems again

Diagnosed a timer problem.
Next shot - no power test.
Jul 16 2002 10:15:10:993AM1020716006Dmitri MossessianOH test looks OK now.
Try for plasma shot
Jul 16 2002 10:46:11:590AM1020716007Dmitri MossessianFizzle

Next shot - Bz down -1310 -> -1320, gas down 23 ms -> 21 ms
Jul 16 2002 01:59:27:013PM1020716008Dmitri MossessianNo plasma. No EF4
Jul 16 2002 02:00:02:013PM1020716009Dmitri MossessianPlasma

Next shot - no changes
Jul 16 2002 02:01:02:170PM1020716010Dmitri MossessianFizzle.

Bz drifted down.

For next shot IC_EF4 -1320 -> -1310
Jul 16 2002 02:25:37:380PM1020716011Dmitri MossessianFizzle.

Bz a little too high, Br a little too low.

For next shot - drop Bz -1310 -> -1320, Br up 0.5 (offset 0.001 -> 0.0015) mT, gas down 21 -> 20 ms
Jul 16 2002 03:02:29:530PM1020716013Dmitri MossessianPlasma.

For next shot - target density to 1e20
Jul 16 2002 03:23:27:027PM1020716014Dmitri MossessianFizzle. Bz jumped up.

Next shot - no changes
Jul 16 2002 04:04:21:213PM1020716015Dmitri MossessianPLasma

Next shot - no changes
Jul 16 2002 04:04:39:933PM1020716016Dmitri MossessianFizzle

Next shot - no changes
Jul 16 2002 04:23:05:710PM1020716017Dmitri MossessianPlasma

Next shot - no changes
Jul 16 2002 05:03:31:743PM1020716018Dmitri MossessianFizzle. Bz, Br and ip traces are virtually indistinguishable from shot 17 (plasma) untill current starts going down.
Therefore:
Next shot - no changes
Jul 16 2002 05:04:16:837PM1020716019Dmitri MossessianFizzle

Last shot

Engineering Operator Comments
ShotTimeTypeStatusComment
107:50:48:690AMTestOkCycle and Gas Test
208:14:19:683AMTestOkCycle and Gas Test
309:12:23:800AMPlasmaOk
409:36:33:470AMPlasmaBadOH1 didn't Fire
509:50:42:027AMPlasmaBadOH1 Didn't Fire
610:11:30:560AMTestOkOH1 Duty Cycle Timer Worked
710:31:05:603AMPlasmaOk
810:48:06:673AMPlasmaBadEF4 accidently disabled
911:04:12:143AMPlasmaOk
1001:50:05:483PMPlasmaOk
1102:13:25:440PMPlasmaOk
1202:35:02:660PMPlasmaOk
1302:57:47:913PMPlasmaOk
1403:16:13:303PMPlasmaOk
1503:34:42:013PMPlasmaOk
1603:53:35:573PMPlasmaOk
1704:16:12:123PMPlasmaOk
1804:45:19:667PMPlasmaOk
1905:02:47:070PMPlasmaOk