Alcator C-Mod Run 1050616 Information

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Miniproposals

Operators
Session leader(s):
Physics operator(s):
Engineering operator(s):Bill Cochran

Engineering Operator Run Comment
MP#296

Session Leader Plans
Entered: Jun 15 2005 12:24:33:317PM
Author: Kirill Zhurovich
Run plan for 1050616:
MP #296 (revised) 'TS/ECE density calibration'

Configure GPC, GPC2 for 4T operation
No RF
L-mode operation, avoid getting ohmic H-modes

Basically repeat the run 1050412c, shots 23-28.

Start with 1050412023:
Bt=3.9 T
Ip=0.87 MA
LSN
nl up to 2e20

Magnetic field and gas puff will be optimized to get ECE cutoffs for all TS spatial channels.

Some shots will be repeated for different optical setup in TS lab.



Physics Operators Plans
Entered: Jun 15 2005 05:19:45:830PM
Author: Ron Parker
Run plan for Thursday, 16 June 2005

MP #296 (revised) "TS/ECE Density Calibration"

SL: Kirill Zhurovic

PO: Ron Parker

Run BEGINS @ 08:00 and ENDS @ 15:00

Overnight ECDC, bake at 60C ending 1 hour before run

Power systems as on 1050412023


A-coil in standard configuration (+Dtop -Dbot -Jtop +Jbot)
C-coil Start=0.3sec, Invert=2.0sec

No ICRF


Gas setup:
fill B-top 6psi D2 Hybrid Enabled (PG4)
fill B-side lower 1psi Argon Hybrid Enabled (PG1)
leave B-side Upper alone Hybrid DISABLED (PG2)
fill B-main 30psi D2 Hybrid Enabled (PG3)


Enable: ECE, VUV, Z-bolo shutter


Run Plan:

Configure GPC, GPC2 for 4T operation
No RF, L-mode operation, avoid getting ohmic H-modes

Basically repeat the run 1050412c, shots 23-28.

Start with 1050412023:
Bt=3.9 T
Ip=0.87 MA
LSN
nl up to 2e20

Magnetic field and gas puff will be optimized to get ECE cutoffs for all TS spatial channels.

Some shots will be repeated for different optical setup in TS lab.

Session Leader Summaries

Physics Operator Summaries
Entered: Jun 16 2005 10:05:57:190AM
Author: Ron Parker
Unfortunately, this run had to be scrubbed after three shots, one fizzle and two
disruptions that occured at about 200 ms. The disruptions were caused by a faulty
chopper power supply.

However, the main problem today was with a heat exchanger used to cool the alternator bearings. This will require dismantling of the primary side of the heat exchanger to fix and will take the rest of today and tomorrow to put back in service. As a result, the run tomorrow will be cancelled and hopefully rescheduled for Monday, the normal maintenance day.

Session Leader Comments
Jun 16 2005 08:05:15:460AM1050616001Kirill ZhurovichNo plasma
Jun 16 2005 08:25:23:383AM1050616002Kirill ZhurovichPlasma for ~ .2 s, not enough...
Jun 16 2005 08:40:55:447AM1050616003Kirill ZhurovichPlasma for ~ .2 s, not enough...

Physics Operator Comments
Jun 16 2005 08:30:39:057AM1050616001Ron Parker
Early start today due to PSFC barbeque.

Begin with shot 1050412023
Jun 16 2005 08:31:21:977AM1050616001Ron Parker
Shot 001 fizzled. Breakdown was late, Bz looks too negative.

Increase EF4 from -1345 to -1300 A. Also take 2 ms off
prefill.
Jun 16 2005 08:29:06:383AM1050616002Ron ParkerShot 2 had better startup, but it disrupted at 0.2 s.

Bz perhaps a bit too high, set EF4 at -1315. Also
BR a bit too negative. Set at -.0004.
Jun 16 2005 08:44:53:087AM1050616003Ron ParkerOn further reflection, there is now a possibility of resuming the run. Stand by.
Jun 16 2005 09:59:36:080AM1050616003Ron ParkerOn further further reflection, and inspection of the heat exchanger, the problem
has been determined to be serious enough to require a prolonged shutdown to fix. The present plan is to scrub the run today and tomorrow, using the time also for maintenance, and run on Monday, the normal maintenance day.

Meanwhile, the two disruptions that occurred today in shots 2 and 3 were associated with lack of vertical stability, attributed to a problem with one of the chopper supplies.
Jun 16 2005 10:01:26:707AM1050616003Ron ParkerShot disrupted again at ~ 200 ms. Startup is fine.

Unfortunately, there is a problems with the heat exchanger that cools the alternator bearings. The fix will require the alternator to be shut down
and the run is now terminated.

Engineering Operator Comments
ShotTimeTypeStatusComment
108:02:12:367AMPlasmaOk
208:20:36:913AMPlasmaOk
308:33:46:413AMPlasmaOk
410:35:44:487AMTestBadEFC power supply test
510:45:16:740AMTestOk
611:06:54:800AMTestOk
711:25:05:160AMTestOk
811:33:53:330AMTestOk
912:01:51:410PMTestOk
1012:11:40:643PMTestOk
1112:26:55:473PMTestOk
1212:38:03:770PMTestOk
1312:46:21:363PMTestOk
1412:52:04:363PMTestOk
1512:58:38:550PMTestOk
1601:06:55:347PMTestOk
1701:18:52:440PMTestOk