Alcator C-Mod Run 1050601 Information

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Miniproposals
Miniproposal:326
Date Filed: 8/26/2002
Title:D, E, and J-port Antenna Evaluation and Comparison
First Author:Steve Wukitch
Session Leader:Steve Wukitch (shots 1-21)

Operators
Session leader(s):Steve Wukitch
Physics operator(s):Jim Irby
Engineering operator(s):Bill Cochran,Andy Pfeiffer

Engineering Operator Run Comment
MP #326: ICRF Antenna Comparison and Evaluation

Session Leader Plans
Entered: May 31 2005 04:46:33:480PM
Author: Steve Wukitch
Engineering setup for Wednesday, 1 June 2005
MP #326: ICRF Antenna Comparison and Evaluation

Session leader: S. Wukitch
Physics operator: J. Irby

Overnight ECDC in D2, 2.e-4 torr; Bake at 60 C.

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

Power systems as on 1050526026 (1.0MA, 5.4 T vanilla plasma)

A-coil configuration: normal [+Dtop -Dbot -Jtop +Jbot] and enabled.

Gas Setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar Hybrid DISABLED (PG1)
leave B-side upper with whatever Hybrid disabled
fill B-main (C-side) with 40 psi D2 Hybrid enabled (PG3)
(During the run we will switch B-main to He4)
NINJA not used today

Torvac setup: machine gate valves to remain open during and after shot.

Enable the following gate valves, assuming no vacuum problems:
ECE, VUV, Z-bolo shutters

Necessary diagnostics: titanium monitoring, video monitors, H/D ratio

-------------------------------------------------------------------------------
all ICRF transmitters to run-on by 8:30 am
-------------------------------------------------------------------------------
We will continue with antenna recovery effort. We will start with D
plasmas and attempt to identify the source of density (machine or
localized to a particular antenna). We will then switcht to He
discharges to see if the voltage handling improves. This test will
include both LSN and USN discharges.

Physics Operators Plans
Entered: May 31 2005 04:50:44:683PM
Author: Jim Irby
Engineering setup for Wednesday, 1 June 2005

MP#325 ICRF Antenna Comparison and Evaluation

Session Leader: Wukitch
Physics operator: Irby

Overnight ECDC in D2, 2.e-4 torr; Bake at 60 C.

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

Power systems as on 1050526017

A-coil configuration: normal [+Dtop -Dbot -Jtop +Jbot] and enabled.

Gas Setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar Hybrid DISABLED (PG1)
fill B-main (C-side) with 40 psi D2 Hybrid enabled (PG3)

Be prepared to switch to Helium fueling mid-run.


Enable the following gate valves: ECE, VUV, Z-bolo shutters

diagnostics: continue to carefully monitor titanium, moly, video monitors,
and H/D ratio

ICRF Setup: All transmitters in run on at 08:30

Session Leader Summaries
Entered: Jun 1 2005 04:45:25:630PM
Author: Steve Wukitch
Run Summary:

Limited number of discharges due to fizzle dud problem (may be related
to power supply problem) and network problems. Spent most of
afternoon troubleshooting power supply problem.

Physics Operator Summaries
Entered: Jun 1 2005 05:40:39:333PM
Author: Jim Irby
Not a very good day. An instrumentation problem with OH1 resulted in
current offsets that could not easily be compensated. We managed to
get only three full length discharges (07, 09 and 22). We stopped trying to
produced plasmas on shot 19 and began tests of the oh1 supply. Several
OH1 only tests were run. After going through the supply looking for
problems we found things were back to normal on shot 21. We
successfully tried for plasma again on shot 22. Several network
problems also complicated and delayed the run.

Session Leader Comments
Jun 1 2005 09:21:55:410AM1050601001Steve Wukitch001 Ip~1 MA, BT~5.4 T, fiducial
D: 0.3 MW [0.5,1.7] sec
E: 1 MW [1.1,1.5] sec
J: 2 MW [0.5,1] sec
result: NTP
Jun 1 2005 09:48:22:520AM1050601002Steve Wukitch002 no power shot
Jun 1 2005 10:01:18:550AM1050601003Steve Wukitch003 NTP
Jun 1 2005 10:24:55:113AM1050601004Steve Wukitch004 NTP
Jun 1 2005 10:26:57:940AM1050601005Steve Wukitch005 NTP
Jun 1 2005 11:04:17:113AM1050601006Steve Wukitch006 NTP
Jun 1 2005 11:23:54:707AM1050601007Steve Wukitch007 Ip~1 MA, BT~5.4 T, fiducial
D: 0.3 MW [0.5,1.7] sec
E: 1 MW [1.1,1.5] sec
J: 2 MW [0.5,1] sec
result: plasma
D: ran max faults
E: max faults - poor match
J: ran max faults

Jun 1 2005 11:24:05:897AM1050601008Steve Wukitch008 NTP
Jun 1 2005 11:36:23:583AM1050601009Steve Wukitch009 Ip~1 MA, BT~5.4 T, fiducial
D: 0.3 MW [0.5,1.7] sec
E: 1 MW [1.1,1.5] sec
J: 2 MW [0.5,1] sec
result: plasma
D: ran max faults
E: max faults
J: ran 9 faults

Jun 1 2005 11:51:38:350AM1050601010Steve Wukitch010 NTP
Jun 1 2005 12:13:38:833PM1050601011Steve Wukitch011 NTP
Jun 1 2005 12:52:34:590PM1050601012Steve Wukitch012 NTP
Jun 1 2005 12:52:45:997PM1050601013Steve Wukitch013 NTP
Jun 1 2005 12:52:54:387PM1050601014Steve Wukitch014 NTP
Jun 1 2005 12:57:57:137PM1050601015Steve Wukitch015 NTP
Jun 1 2005 01:19:33:897PM1050601016Steve Wukitch016 NTP
Jun 1 2005 03:53:36:787PM1050601017Steve Wukitch017 NTP
long break due to network problem

Jun 1 2005 03:53:46:820PM1050601018Steve Wukitch018 NTP

Physics Operator Comments
Jun 1 2005 09:52:05:817AM1050601002Jim Irbyno power cycle test to make sure the gas level is okay --- while we figure out the flux loop problem.

gas factor of two high, but gatevalves were closed


Jun 1 2005 09:57:59:253AM1050601003Jim Irbyunable to figure out which flux loop was causing the problem --- try again

added 2 ms to prefill

dud #2 --- too little gas!


Jun 1 2005 10:21:44:850AM1050601004Jim Irbyincreased prefill by 4 ms to 28 ms total

fizzle

br0 and bz0 are certainly off --- still not sure of cause


Jun 1 2005 10:36:47:020AM1050601005Jim Irbybr0 from -0.0005 to 0.0000 T
ef4 from -1300 to -1340 A

fizzle

br0 still low at breakdown

bzo looks okay


Jun 1 2005 10:55:10:020AM1050601006Jim Irbyincreased br0 to +0.00025 T

dud

br0 looks very good

bz0 swinging rapidly --- time history changed from last week


Jun 1 2005 11:29:10:537AM1050601007Jim Irbycell access to check out gas puff and/or dnb

increased ef4 from -1340 to -1320

increased prefill to 30 ms from 28.

plasma into rampdown

nice h-mode following rf

BIII signal from K-top is now back in operation

h/(h+d) 3.5%

dust still seen on DANT view
Jun 1 2005 11:28:35:363AM1050601008Jim Irbyrepeat

fizzle ---

Jun 1 2005 11:46:30:287AM1050601009Jim Irbyrepeat

plasma into rampdown

h/(h+d) at 4%

2 MW of rf from J


Jun 1 2005 11:51:53:897AM1050601010Jim Irbyno changes

fizzle --- not a good pattern

pressure is creeping up

br0 evolving
Jun 1 2005 12:05:58:003PM1050601011Jim Irbybr0 from +0.00025 to 0.0000
reduced prefill by 2 ms to 28 ms

dud --- I guess I know which way to go now....
Jun 1 2005 12:17:22:457PM1050601012Jim Irbyprefill to 32 ms from 28.

fizzle

gas low, br0 low
Jun 1 2005 12:38:04:707PM1050601013Jim Irbybr0 back to 0.00025 T
gas prefill to 34 ms from 32.

fizzle

breakdown late
Jun 1 2005 12:53:02:387PM1050601014Jim Irbyreduced prefill to 30 from 32 ms

fizzle

still have late breakdown
Jun 1 2005 01:05:40:523PM1050601015Jim Irbyprefill from 32 to 30 ms

increased gain on OH1 supply from 1 to 1.25 --- may have made offset worse

fizzle


Jun 1 2005 01:19:50:070PM1050601016Jim Irbyoh1 supply gain from 1.25 back to 1.

prefill from 30 to 28 ms

dud --- no range in gas

stopping for Bill C to check Oh1 supply control...
Jun 1 2005 03:38:07:367PM1050601018Jim Irbyno changes, but very long delay as we checked supplies and fixed network problems

fizzle

looks like we have a instrumentation problem problem with the voltage reporting from the oh1 supply. Seem to have lower voltage in supply than on the bus.
Jun 1 2005 03:55:14:350PM1050601019Jim Irbyoh1 plc test with voltage limit set at 500 volts
forward bridge


Jun 1 2005 04:14:23:037PM1050601020Jim Irby1 kA PLC test === repeat of 1050203015 --- compare voltages
Jun 1 2005 05:20:54:507PM1050601021Jim Irbyrepeat
Jun 1 2005 05:29:07:897PM1050601022Jim IrbyBill and Gary went through OH1 supply doing various tests. No problem found, but the supply has been fixed. No OH1 current offset.

plasma into rampdown


Engineering Operator Comments
ShotTimeTypeStatusComment
109:14:34:740AMPlasmaOk
209:39:10:443AMTestOk
309:52:54:647AMPlasmaOk
410:05:31:850AMPlasmaOk
510:25:36:863AMPlasmaOk
610:38:35:927AMPlasmaOk
711:02:45:520AMPlasmaOk
811:15:26:490AMPlasmaOk
911:32:14:160AMPlasmaOk
1011:45:12:787AMPlasmaOk
1111:57:44:473AMPlasmaOk
1212:10:24:690PMPlasmaOk
1312:22:52:347PMPlasmaOk
1412:37:58:223PMPlasmaOk
1512:55:39:750PMPlasmaOk
1601:08:32:630PMPlasmaOk
1703:13:43:677PMPlasmaBadDatasystem problems
1803:24:08:020PMPlasmaOk
1903:42:16:770PMTestOkOH1 Test
2003:55:09:693PMTestOk
2104:58:09:710PMTestOk
2205:10:38:757PMPlasmaOk