Alcator C-Mod Run 1000405 Information

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Miniproposals
Miniproposal:
Date Filed:
Title:
First Author:
Session Leader:Steve Wolfe (shots 1-32)

Operators
Session leader(s):Steve Wolfe
Physics operator(s):Robert Granetz
Engineering operator(s):Gary Dekow,Bill Cochran

Engineering Operator Run Comment
Startup and conditioning with normal field direction. Begin with power s

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:22:757PM
Author: To Be Determined
Session Leader Summary for Wed. April 5, 2000

Startup and Conditioning Run
SL: wolfe
PO: Granetz
EO: Cochran,Dekow

The goals of today's run were to get plasmas with the field in the normal
(negative) direction; work on the startup; continue tokamak conditioning; and
provide targets for diagnostic alignment, calibration, checkout, etc.

ECDC in Helium was performed on Tuesday and for a couple hours prior to the
beginning of the run. The idea of He ECDC was to deplete the walls, since
during last week's run the walls were apparently the principal gas source,
leading to uncontrolled density increases with the puff valves shut for most
of the discharge.

The run began with power system testing of all supplies, since the bus work
had just been reversed. This was completed with no problems (except for some
computer crashes which are being blamed on the new network switches).

The first plasma attempt was shot 14, which produced a flash. First plasma was
#15, with no changes. The plasma lasted only to .32sec, which was typical of
the rest of the day. The best shot of the day was #18, which lasted to almost
0.9sec. There was no sign of excessive gas influx from the
walls. Nevertheless, a marfe typically set in at about 0.3 sec, with an
accompanying rise in radiated power and loop voltage. Usually this was
followed shortly by a disruption. There was some indication that the marfe was
precipitated by injections, and meteor showers were observed on the fast
camera at the correct time. The marfe preceded oh1 crossover, and while there
was sometimes a coincidence of crossover and the disruption, this relationship
is probably not causal.

Changes to the position and shape programming, including keeping the plasma
limited (shots #30,32) as well as increasing the gaps (#28), did not affect
the problem at 0.3sec.

The early disruption behavior is reminiscent of the period last year when the
gas feed line was drooping into the plasma. However, we have not yet observed
any evidence of iron, etc. in the spectroscopy. This should be confirmed
during the next run, especially if the short shots persist.

Physics Operator Summaries
Entered: Jul 7 2004 04:37:10:240PM
Author: To Be Determined
Physics operator summary for run 1000405:

MP ? -- Startup and conditioning with normal field direction

SL: S. Wolfe
PO: R. Granetz
EO: B. Cochran/G. Dekow

Summary: Not a great day. Only one plasma made it far into flattop (shot 18).
There were many plasmas that died around t=0.35-0.40 s, which may
have had something to do with the marfing going on, but it's not
clear at all. It may just be that the machine needs to clean up
more. We tried moving the plasma away from the wall, then tried
limiting it, all to no avail. Also, the startup was not very
robust, resulting in a number of fizzles and even one dud.

Scorecard: 12 plasmas
6 fizzles
1 dud
13 tests
0 aborted
----------
32 total

-------------------------------------------------------------------------------

Engineering setup for Wednesday, 1000405:

Power supply tests (with normal bus direction) start at 08:30.
Plasma run will begin at 10:30 and end at 17:00

Overnight ECDC in helium, stopping 1 hour prior to the run.

Power system setup as on 991110005

Note: Fizzle detector should be on from t=0.080 to 1.7 s

Gas setup - fill B-top with 6 psi of D2 Hybrid enabled
fill B-side lower with 1 psi of Ar Hybrid DISABLED
leave B-side upper as is Hybrid DISABLED
fill C-side with 30 psi of D2 Hybrid enabled
leave J-bottom as is Hybrid DISABLED

The following gate valves should be enabled, assuming no vacuum problems:
ECE, VUV

-------------------------------------------------------------------------------

Physics operator's setup for Wednesday, 1000405

MP ? -- Startup and conditioning with normal field direction

Session leader: S. Wolfe
Physics operator: R. Granetz

The primary goals of this week's runs are:

1) Get plasma with normal (negative) field
2) Machine conditioning with tokamak plasmas
3) Checkout and commissioning of available diagnostics

Load from shot 991110005 (typical 0.8 MA, 5.2 T, normal field direction), and
update all relevant estimators in PCS to use partial flux loop F27 in place
of F28.

-------------------------------------------------------------------------------

Note from Jim Irby:
"A TC fault kept us from re-starting ecdc last night. So you
only got about 13 hours of ECDC. About 11 hours yesterday and
2 hours this morning from 6:00 to 8:00."

Note: the ECDC was in helium.

Hybrid coldstart done; no errors found

Loaded 1000405000 (saved from yesterday---see logbook entry about
that), which is based on shot 991110005.

-------------------------------------------------------------------------------

Shot 01 -- Test; no power.

Shot 02 -- Test; EF4 under PLC control. OK.

Shot 03 -- Test; EF2U under PLC control. OK.

Delay due to partial crash and reboot of computer cluster.

Shot 04 -- Test; EF2L under PLC control.

Shot 05 -- Test; EFC under PLC control. OK.

Shot 06 -- Test; EF3 under PLC control. OK.

Delay due to crash and reboot of node RHONE (engineering workstation).

Shot 07 -- Test; OH2U under PLC control. OK.

Shot 08 -- Test; OH2L under PLC control. OK.

Shot 09 -- Test; OH1 under PLC control. OK.

Shot 10 -- Test; EF1U under PLC control. OK.

Shot 11 -- Test; EF1L under PLC control. OK.

Shot 12 -- Test; TF 50 kA under PLC control. OK.

Shot 13 -- Test; TF 100 kA under PLC control. OK.

End of power supply tests. Time: 11:15
Start of plasma run. Set pre-fill gas puff at 20 ms.

Shot 14 -- Fizzle. 40 kA. Null looks reasonable.

Next shot: no changes.

Shot 15 -- Plasma. Terminated at t=0.33 s. Runaway shot.

Next shot: change IC_EF4 by +15 A, increase pre-fill puff
from 20 to 22 ms.

Shot 16 -- Plasma. Terminated at t=0.44 s. Good early current rise.
Hard x-rays are nearly all gone. An impurity event happened
around t=0.31 s which took a bite out of the plasma current.
We can see it on the fast video camera.

Next shot: no changes.

Shot 17 -- Plasma. Terminated at t=0.38 s. Similar to preceding shot,
except lots of hard x-rays. Current rise wasn't quite as nice.

Next shot: increase pre-fill puff from 22 to 25 ms.

Shot 18 -- Plasma. Lasted until t=0.87 s. Much fewer hard x-rays. Nice
current rise. Line density reaches 1e20 m-2. Still lots of
marfing.

Next shot: tweak RCUR programming around the time of cross-over.

Shot 19 -- Plasma. Terminated at t=0.32 s. Lots of runaways.

Next shot: tweak IC_EF4 again by +15 A. Start gas valve
programming 5 ms earlier (now at t=25 ms instead of 30 ms).

Shot 20 -- Plasma. Terminated at t=0.41 s. Much fewer hard x-rays. Nice
current rise.

Next shot: try tweaking RCUR programming again, this time
pushing things 200 ms earlier (per Steve's suggestion).

Shot 21 -- Fizzle.

Next shot: change IC_EF4 by -10 A.

Shot 22 -- Fizzle. Fields and pressure are essentially the same as
previous plasma shots.

Next shot: try tweaking Br0 up by +0.0005 T

Shot 23 -- Fizzle.

Next shot: reload shot 18

Shot 24 -- Plasma. Terminated at t=0.40 s. Magnetics TRAQ_1 data is
corrupted. Great breakdown and early ramp.

Next shot: import segment 2 from shot 21, in order to recover
the RCUR changes made before reloading shot 18.

Shot 25 -- Plasma. Terminated at t=0.34 s.

Next shot: reduce RCUR by 3 mm for most of the flattop.

Shot 26 -- Plasma. Terminated at t=0.34 s. Nearly identical to the
preceding shot.

Next shot: increase CLEARIN by 5 mm.

Shot 27 -- Fizzle.

Next shot: no changes

Shot 28 -- Plasma. Terminated at t=0.34 s again.

Next shot: Steve wants to try a limited shot. Decrease CLEARIN
from -5 mm to -5 cm for the entire shot.

Shot 29 -- Fizzle.

Next shot: tweak Br0 offset by -0.0005 T.

Shot 30 -- Plasma. Terminated at t=0.35 s. Plasma may have touched
outboard limiter.

Next shot: reduce RCUR by 1 cm over the entire shot.

Shot 31 -- Dud. Hard to believe.

Next shot: tweak IC_EF4 by -15 A. Also drop programmed density
to nl_04=0.5e20 m-2.

Shot 32 -- Plasma. Became disruptive at t=0.40 s and finally died at
t=0.47 s.

End of run.

Session Leader Comments
Apr 5 2000 11:18:08:780AM1000405013Steve Wolfeshot 13: 100kA tf

Next shot: First try for plasma with normal field.
Apr 5 2000 11:52:27:390AM1000405015Steve Wolfeshot 14: try for plasma.
fizzle
Apr 5 2000 11:54:28:590AM1000405015Steve Wolfeshot 15: repeat.

Plasma to .32sec; dies at crossover.
Lots of runaways.
Needs more gas early, and more Bz early.
Apr 5 2000 12:18:22:483PM1000405016Steve Wolfeshot 16: Another short one, 430msec.
runaway dump at .35
Current rise is much better, still looks a little outside.
CII ~.005

Next shot: repeat
Apr 5 2000 12:46:53:250PM1000405018Steve Wolfeshot 17: similar. lasted to 380msec
Lots of runaways again. Current rise has a hesitation.
bd a little later (6.4msec)
Apr 5 2000 12:54:27:670PM1000405018Steve Wolfeshot 18: plasma to .87sec, possible vertical problem at the end.
Some runaway dumps, not nearly as bad.
current rise is better. Br0 may be a little negative.
Apr 5 2000 01:09:44:343PM1000405019Steve Wolfeshot 19: tweak to delay RCUR move out from .28 to .35sec
plasma to .32, lots of runaways again.
The rcur tweak didn't help.
CII~.01
Apr 5 2000 01:40:47:467PM1000405020Steve Wolfeshot 20: move seg 1 pg3 puff earlier by 5ms.
make ef4 another 15a more positive and hope we don't lose the startup.

plasma to .41sec; still a small runaway dump.
Apr 5 2000 01:51:35:593PM1000405021Steve Wolfeshot 21: Try moving the rcur shift before crossover.
fizzle
Apr 5 2000 02:17:40:013PM1000405023Steve Wolfeshot 22: take 10 amps off ef4
Try moving the rcur shift before crossover.

another fizzle.
Apr 5 2000 02:17:58:903PM1000405023Steve Wolfeshot 23: br tweak
another fizzle.
Apr 5 2000 02:44:53:500PM1000405024Steve Wolfeshot 24: reload shot 18.

plasma to .4sec. Startup looks good.
Magnetics data is screwed up, traq failure?

Next shot: copy seg 2 from shot 21
Apr 5 2000 03:04:21:403PM1000405025Steve Wolfeshot 25: copy seg 2 from shot 21 to put back early rcur shift.

another short plasma .330
Something is coming in at .3sec, regardless of what we do to rcur
Apr 5 2000 03:15:51:670PM1000405026Steve Wolfeshot 26: rcur in by 3mm
almost identical.
Apr 5 2000 03:35:17:937PM1000405027Steve Wolfeshot 27: increase clearin by 5mm
fizzle.
Apr 5 2000 03:47:23:967PM1000405028Steve Wolfeshot 28: repeat:increase clearin by 5mm
almost identical to 26.

next shot: limit it.
Apr 5 2000 04:02:54:640PM1000405029Steve Wolfeshot 29: keep it limited the whole shot (clearin=-.05)
fizzle.

try tweaking br in the other direction
Apr 5 2000 04:22:11:170PM1000405030Steve Wolfeshot 30: try tweaking br in the other direction
plasma to .35. It is limited; it doesn't care!
It gets very close on the outside, because we didn't move
rcur when we changed clearin.

next shot: move rcur in by 1cm
Apr 5 2000 04:42:01:170PM1000405031Steve Wolfeshot 31: move rcur in by 1cm
dud!

Physics Operator Comments
Apr 5 2000 09:00:45:797AMRobert GranetzEngineering setup for Wednesday, 1000405:

Power supply tests (with normal bus direction) start at 08:30.
Plasma run will begin at 10:30 and end at 17:00

Overnight ECDC in helium, stopping 1 hour prior to the run.

Power system setup as on 991110005

Note: Fizzle detector should be on from t=0.080 to 1.7 s

Gas setup - fill B-top with 6 psi of D2 Hybrid enabled
fill B-side lower with 1 psi of Ar Hybrid DISABLED
leave B-side upper as is Hybrid DISABLED
fill C-side with 30 psi of D2 Hybrid enabled
leave J-bottom as is Hybrid DISABLED

The following gate valves should be enabled, assuming no vacuum problems:
ECE, VUV
Apr 5 2000 09:00:58:043AMRobert GranetzPhysics operator's setup for Wednesday, 1000405

MP ? -- Startup and conditioning with normal field direction

Session leader: S. Wolfe
Physics operator: R. Granetz

The primary goals of this week's runs are:

1) Get plasma with normal (negative) field
2) Machine conditioning with tokamak plasmas
3) Checkout and commissioning of available diagnostics

Load from shot 991110005 (typical 0.8 MA, 5.2 T, normal field direction), and
update all relevant estimators in PCS to use partial flux loop F27 in place
of F28.
Apr 5 2000 09:01:10:840AMRobert Granetz Note from Jim Irby:
"A TC fault kept us from re-starting ecdc last night. So you
only got about 13 hours of ECDC. About 11 hours yesterday and
2 hours this morning from 6:00 to 8:00."

Note: the ECDC was in helium.

Hybrid coldstart done; no errors found

Loaded 1000405000 (saved from yesterday---see logbook entry about
that), which is based on shot 991110005.
Apr 5 2000 09:01:25:390AM1000405001Robert GranetzShot 01 -- Test; no power.
Apr 5 2000 09:01:37:530AM1000405002Robert GranetzShot 02 -- Test; EF4 under PLC control.
Apr 5 2000 09:31:34:780AM1000405003Robert GranetzShot 03 -- Test; EF2U under PLC control.
Apr 5 2000 09:32:22:687AM1000405003Robert GranetzDelay due to partial crash and reboot of computer cluster.
Apr 5 2000 09:40:00:967AM1000405004Robert GranetzShot 04 -- Test; EF2L under PLC control.
Apr 5 2000 09:53:03:873AM1000405005Robert GranetzShot 05 -- Test; EFC under PLC control. OK.
Apr 5 2000 09:56:05:873AM1000405006Robert GranetzShot 06 -- Test; EF3 under PLC control. OK.
Apr 5 2000 10:10:35:950AM1000405006Robert GranetzDelay due to crash and reboot of node RHONE (engineering workstation).
Apr 5 2000 10:24:07:840AM1000405007Robert GranetzShot 07 -- Test; OH2U under PLC control. OK.
Apr 5 2000 10:29:26:450AM1000405008Robert GranetzShot 08 -- Test; OH2L under PLC control. OK.
Apr 5 2000 10:39:06:577AM1000405009Robert GranetzShot 09 -- Test; OH1 under PLC control. OK.
Apr 5 2000 10:47:09:577AM1000405010Robert GranetzShot 10 -- Test; EF1U under PLC control. OK.
Apr 5 2000 10:57:31:483AM1000405011Robert GranetzShot 11 -- Test; EF1L under PLC control. OK.
Apr 5 2000 11:03:55:060AM1000405012Robert GranetzShot 12 -- Test; TF 50 kA under PLC control. OK.
Apr 5 2000 11:14:50:980AM1000405013Robert GranetzShot 13 -- Test; TF 100 kA under PLC control. OK.

End of power supply tests. Time: 11:15
Start of plasma run. Set pre-fill gas puff at 20 ms.
Apr 5 2000 11:41:17:577AM1000405014Robert GranetzShot 14 -- Fizzle. 40 kA. Null looks reasonable.

Next shot: no changes.
Apr 5 2000 12:01:29:890PM1000405015Robert GranetzShot 15 -- Plasma. Terminated at t=0.33 s. Runaway shot.

Next shot: change IC_EF4 by +15 A, increase pre-fill puff
from 20 to 22 ms.
Apr 5 2000 12:21:59:047PM1000405016Robert GranetzShot 16 -- Plasma. Terminated at t=0.44 s. Good early current rise.
Hard x-rays are nearly all gone. An impurity event happened
around t=0.31 s which took a bite out of the plasma current.
We can see it on the fast video camera.

Next shot: no changes.
Apr 5 2000 12:36:32:950PM1000405017Robert GranetzShot 17 -- Plasma. Terminated at t=0.38 s. Similar to preceding shot,
except lots of hard x-rays. Current rise wasn't quite as nice.

Next shot: increase pre-fill puff from 22 to 25 ms.
Apr 5 2000 01:11:10:093PM1000405019Robert GranetzShot 19 -- Plasma. Terminated at t=0.32 s. Lots of runaways.

Next shot: tweak IC_EF4 again by +15 A. Start gas valve
programming 5 ms earlier (now at t=25 ms instead of 30 ms).
Apr 5 2000 01:35:17:233PM1000405020Robert GranetzShot 20 -- Plasma. Terminated at t=0.41 s. Much fewer hard x-rays. Nice
current rise.

Next shot: try tweaking RCUR programming again, this time
pushing things 200 ms earlier (per Steve's suggestion).
Apr 5 2000 01:50:07:107PM1000405021Robert GranetzShot 21 -- Fizzle.

Next shot: change IC_EF4 by -10 A.
Apr 5 2000 02:13:20:547PM1000405022Robert GranetzShot 22 -- Fizzle. Fields and pressure are essentially the same as
previous plasma shots.

Next shot: try tweaking Br0 up by +0.0005 T
Apr 5 2000 02:20:33:233PM1000405023Robert GranetzShot 23 -- Fizzle.

Next shot: reload shot 18
Apr 5 2000 02:47:12:840PM1000405024Robert GranetzShot 24 -- Plasma. Terminated at t=0.40 s. Magnetics TRAQ_1 data is
corrupted. Great breakdown and early ramp.

Next shot: import segment 2 from shot 21, in order to recover
the RCUR changes made before reloading shot 18.
Apr 5 2000 03:09:07:750PM1000405025Robert GranetzShot 25 -- Plasma. Terminated at t=0.34 s.

Next shot: reduce RCUR by 3 mm for most of the flattop.
Apr 5 2000 03:19:34:140PM1000405026Robert GranetzShot 26 -- Plasma. Terminated at t=0.34 s. Nearly identical to the
preceding shot.

Next shot: increase CLEARIN by 5 mm.
Apr 5 2000 03:35:35:107PM1000405027Robert GranetzShot 27 -- Fizzle.

Next shot: no changes
Apr 5 2000 03:49:12:683PM1000405028Robert GranetzShot 28 -- Plasma. Terminated at t=0.34 s again.

Next shot: Steve wants to try a limited shot. Decrease CLEARIN
from -5 mm to -5 cm for the entire shot.
Apr 5 2000 04:05:10:920PM1000405029Robert GranetzShot 29 -- Fizzle.

Next shot: tweak Br0 offset by -0.0005 T.
Apr 5 2000 04:24:20:450PM1000405030Robert GranetzShot 30 -- Plasma. Terminated at t=0.35 s. Plasma may have touched
outboard limiter.

Next shot: reduce RCUR by 1 cm over the entire shot.
Apr 5 2000 04:44:17:810PM1000405031Robert GranetzShot 31 -- Dud. Hard to believe.

Next shot: tweak IC_EF4 by -15 A. Also drop programmed density
to nl_04=0.5e20 m-2.
Apr 5 2000 05:02:35:030PM1000405032Robert GranetzShot 32 -- Plasma. Became disruptive at t=0.40 s and finally died at
t=0.47 s.

End of run.

Engineering Operator Comments
ShotTimeTypeStatusComment
108:50:29:483AMTestBadTree Disabled
208:57:30:670AMTestOkEF4 Forward Bridge Test
309:06:31:547AMTestBad
409:37:47:467AMTestOkEF2L Test
509:46:12:653AMTestOkEFc Test
609:53:21:280AMTestOkEF3 Test
710:21:18:717AMTestOkOH2U Test
810:27:55:450AMTestOkOH2L TEST
910:35:37:123AMTestOkOH1 Test
1010:45:13:547AMTestOkEF1U Test
1110:54:42:420AMTestOkEF1L Test
1211:02:13:577AMTestOkTF 50KA Test
1311:12:35:123AMTestOkTF 100KA Test
1411:36:28:903AMPlasmaOkNo Faults
1511:50:38:700AMPlasmaOkPLasma
1612:06:10:670PMPlasmaOk
1712:25:27:890PMPlasmaOk
1812:46:25:890PMPlasmaOk
1901:03:53:013PMPlasmaOk
2001:21:57:653PMPlasmaBadOH1 Self Powered Circuit Fired
2101:45:09:500PMPlasmaOk
2202:00:22:200PMPlasmaOk
2302:15:30:590PMPlasmaOk
2402:35:31:280PMPlasmaBadOH1 self powered circuit fired
2502:56:16:810PMPlasmaOk
2603:13:37:750PMPlasmaOk
2703:29:29:717PMPlasmaOk
2803:42:58:263PMPlasmaOk
2904:00:55:543PMPlasmaOk
3004:15:04:653PMPlasmaOk
3104:34:06:717PMPlasmaOk
3204:49:29:390PMPlasmaOk