Alcator C-Mod Run 990421 Information

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Miniproposals
Miniproposal:214
Date Filed: 1/5/1999
Title:D and E-port RF System Commissioning
First Author:Steve Wukitch
Session Leader:Steve Wukitch (shots 1-11)

Operators
Session leader(s):Steve Wukitch
Physics operator(s):Joseph Snipes
Engineering operator(s):Frank Silva

Engineering Operator Run Comment
MP214 ICRF Conditioning/Wukitch/Silva

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:20:197PM
Author: To Be Determined
Run Plan for 990421 ICRF Conditioning

Engineering Setup for Tuesday, 990421 ICRF Conditioning

Load from 990420021

The run will not start until 9:00 am in order to allow 1 hour for ICRF
maintenance.

2 hours of ECDC in D2

Vacuum conditioned D and E-port antennas to ~40 kV last night.

Gas setup - fill B-top with 6 psi of D2 Hybrid enabled
fill B-side lower with 1 psi of Ar Hybrid enabled
fill B-side upper with 6 psi of H2 Hybrid DISABLED
fill C-side with 30 psi of D2 Hybrid enabled
fill J-bottom with 30 psi of D2 Hybrid enabled

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

ECE, VUV

-------------------------------------------------------------------------------
Run Plan for 990420

MP 214: ICRF conditioning

We will use J-bottom gas valve for the main D2 gas after 0.1 sec into the
discharge to test if this affects antenna performance.

001 Laser interferometer test
002 plasma elmy H-mode
screen overcurrent on #1 (D-port) ~0.7 sec
1 MW from E

next shot: adjust tune on D and E
raise power to 1.2 MW each

003 plasma elmy H-mode
screen overcurrent on #1 (D-port) ~0.65 sec
1.3 MW from E

next shot: lower D-port power

004 plasma elmy H-mode
still have screen current excursions on #1
faults on D at 1 sec
1.3 MW from E
1.4 MW from D

next shot: repeat with 10% more power on D

005 plasma H-mode
screen current fault on #1 after 1 sec
faults on D after 1 sec
1.3 MW from E
1.4 MW from D

006 plasma H-mode
screen current fault on #1 after 1 sec
faults on D after 1 sec
1.3 MW from E
1.4 MW from D

oops no discharge - igor glitch

007 computer glitch

008

next shot: ramp D-port to get power calibration
D-port MW coefficients: [-.839701,.516632,-2.32395]

009 plasma H-mode
good ramp

010 plasma
few trips on D-port
clean E

next shot: increase power on D by 20%

011 plasma
few trips on D-port

[-.839701,.516632,-2.32395]
J-port vacuum testing

Bira3 [kW] kkV] Bira4
579 .5-1. .5-1.
580 1.-1.5 12 .4 kV 1.-1.5 12
581 1.-1.5 12 1.-1.5 12

checked DC2 signals and set thresholds and ratios for arc detection

582 1.-1.5 12 1.-1.5 12
good gas puff (5.e-7)
583
584-586 repeats
587 first decent match for #3
588 first decent match for #4
589 good shot for both
590 1.4-1.5 49 1.9-2 66

Good progress on J. It took about 9 shots into vacuum for #3 and #4
to have a good match. We think this was due to multipacking. The match
look excellent with network analyzer and initially it looked poor into
vacuum. A signature of the multipacking is the reflected power
increases while the forword drops and a significant amount of gas
evolves (5x10-6 torr). We still have problems with data aquisition,
signal processing, and arc detection thresholds and ratios. Further
work is needed to obtain DC1 calibration factors.

D and E conditioning improved today - 2.5 MW was injected with few
faults. However a limited number of discharges due to a loss of DI
water (FMIT#1 water input broke open) did not allow adequate
assessment of gas fueling issue. One interesting item was that about
1.5 MW was obtained from D at 80.6 MHz instead of 80.5 MHz.
Difficulty was experienced in tuning, power control, and a lower
threshold for screen overcurrent crowbars.

Physics Operator Summaries
Entered: Jul 7 2004 04:37:00:957PM
Author: To Be Determined
990421001 SNIPES PHYSICS_OPERATOR Apr 21 1999 9:40:55:576AM
. . . . . . . . . . . . . . . . . . . .
MP214 ICRF Conditioning
Engineer in Charge: Frank Silva
Physics Operator: Joseph Snipes
Session Leader: Steve Wukitch

Start with 990420021 with main D2 gas fuelling after 0.1 sec from J-bottom to
see if local gas near the antennas may be causing arcing in the antennas at
high density.

Summary: The machine ran rather well. The RF ran O.K. with up to 2.5 MW for
about 0.5 sec. However, they had problems tuning and a cooling water pipe
burst on one of the RF transmitters flooding the RF area of the power room and
ending the run at about 12:30 pm. By analyzing the fast magnetic pick-up coil
signals, I noticed that the RF beat frequency had shifted to 600 kHz rather
than its usual 500 kHz. After the run, Fridberg and I checked and found that
indeed, the D port frequency had been inadvertently set to 80.6 MHz instead of
its usual 80.5 MHz. It has now been reset to 80.5 MHz for tomorrow.

Shot 1: Loaded 990420021. Coldstart of hybrid is o.k. Start with an EF3 only
test since there was a problem with EF3 on the last shot yesterday.
Shot 2: EF3 test went fine on shot 1. This shot also went well. Plasma.
Type III ELMy H-mode throughout RF pulse. RF reached 2 MW briefly,
then dropped to 1 MW for a bit more than 0.5 sec.
Shot 3: Good shot. In and out of Type III ELMy H-mode/ELM-free H-mode
throughout the RF pulse. RF briefly touched 3 MW then dropped to about
1.3 MW throughout the remainder of the RF pulse.
Shot 4: Good shot. RF stayed on except for a few glitches at nearly 2.5 MW.
Short EDA followed by ELM-free and Type III ELMy H-modes.
Shot 5: Good shot. RF seems to be improving. Steady EDA-like H-mode, though
with very high recycling. RF stays on at about 2.6 MW for most of the
flattop, then trips near the end.
Shot 6: Good shot. Steady EDA-like H-mode, though with very high recycling.
RF stays on at about 2.6 MW for most of the flattop, then trips near
the end. Reduced prepuff from 18 msec to 16 msec.
Shot 7: Short delay for RF maintenance in the power room. Problem between
IGOR and state in the computers. This shot was not run.
Shot 8: Dud due to problems resetting after the IGOR problem on shot 7. No TF.
Shot 9: Good shot. Ramping RF power up to 2.5 MW. Alternating Type III ELMy
and ELM-free H-mode.
Shot 10:Good shot. RF power up to 2.3 MW throughout most of the pulse.
Ratty H-mode changing between a brief EDA at the beginning to Type III
ELMy and ELM-free alternating H-mode.
Shot 11:Good shot. RF power up to 2.4 MW throughout most of the pulse.
Ratty H-mode similar to shot 10.
Shot 12:Raised nl04 programming to 1.4 x 10^20 m^-2. Reduced prepuff to 14 msec
duration. No chance to run the shot. A water pipe burst on the
cooling for one of the RF transmitters and the RF power room area is
flooded. End of the run.

Summary:
11 shots
8 good plasmas
1 test shot
2 computer faults

Session Leader Comments
Apr 21 1999 09:39:11:013AM990421002Steve Wukitch002 plasma elmy H-mode
screen overcurrent on #1 (D-port) ~0.7 sec
1 MW from E
Apr 21 1999 10:06:14:937AM990421003Steve Wukitch003 plasma elmy H-mode
screen overcurrent on #1 (D-port) ~0.65 sec
1.3 MW from E

next shot: lower D-port power

Apr 21 1999 10:20:04:293AM990421004Steve Wukitch004 plasma elmy H-mode
still have screen current excursions on #1
faults on D at 1 sec
1.3 MW from E
0.8 kW from D

next shot: repeat with 10% more power on D
Apr 21 1999 11:04:57:763AM990421005Steve Wukitch005 plasma H-mode
screen current fault on #1 after 1 sec
faults on D after 1 sec
1.3 MW from E
1.4 MW from D
Apr 21 1999 11:05:17:230AM990421006Steve Wukitch006 plasma H-mode
screen current fault on #1 after 1 sec
faults on D after 1 sec
1.3 MW from E
1.4 MW from D
Apr 22 1999 08:40:07:390AM990421009Steve Wukitch009 plasma H-mode
good ramp

Apr 22 1999 08:40:21:733AM990421010Steve Wukitch010 plasma
few trips on D-port
clean E

next shot: increase power on D by 20%
Apr 22 1999 08:40:38:140AM990421011Steve Wukitch011 plasma
few trips on D-port

Physics Operator Comments
Apr 21 1999 09:40:55:577AM990421001Joseph SnipesMP214 ICRF Conditioning
Engineer in Charge: Frank Silva
Physics Operator: Joseph Snipes
Session Leader: Steve Wukitch

Start with 990420021 with main D2 gas fuelling after 0.1 sec from J-bottom to
see if local gas near the antennas may be causing arcing in the antennas at high
density.

Shot 1: Loaded 990420021. Coldstart of hybrid is o.k. Start with an EF3 only
test since there was a problem with EF3 on the last shot yesterday.
Apr 21 1999 09:40:25:623AM990421002Joseph SnipesShot 2: EF3 test went fine on shot 1. This shot also went well. Plasma.
Type III ELMy H-mode throughout RF pulse. RF reached 2 MW briefly, then
dropped to 1 MW for a bit more than 0.5 sec.
Apr 21 1999 10:02:12:420AM990421003Joseph SnipesShot 3: Good shot. In and out of Type III ELMy H-mode/ELM-free H-mode
throughout the RF pulse. RF briefly touched 3 MW then dropped to about
1.3 MW throughout the remainder of the RF pulse.
Apr 21 1999 10:13:33:497AM990421004Joseph SnipesShot 4: Good shot. RF stayed on except for a few glitches at nearly 2.5 MW.
Short EDA followed by ELM-free and Type III ELMy H-modes.
Apr 21 1999 10:39:09:343AM990421005Joseph SnipesShot 5: Good shot. RF seems to be improving. Steady EDA-like H-mode, though
with very high recycling. RF stays on at about 2.6 MW for most of the
flattop, then trips near the end.
Apr 21 1999 10:52:37:890AM990421006Joseph SnipesShot 6: Good shot. Steady EDA-like H-mode, though with very high recycling.
RF stays on at about 2.6 MW for most of the flattop, then trips near
the end. Reduced prepuff from 18 msec to 16 msec.
Apr 21 1999 11:19:35:717AM990421007Joseph SnipesShot 7: Short delay for RF maintenance in the power room. Problem between
IGOR and state in the computers. This shot was not run.
Apr 21 1999 11:24:10:810AM990421008Joseph SnipesShot 8: Dud due to problems resetting after the IGOR problem on shot 7. No TF.
Apr 21 1999 12:00:45:840PM990421009Joseph SnipesShot 9: Good shot. Ramping RF power up to 2.5 MW. Alternating Type III ELMy
and ELM-free H-mode.
Apr 21 1999 12:04:10:263PM990421010Joseph SnipesShot 10:Good shot. RF power up to 2.3 MW throughout most of the pulse.
Ratty H-mode changing between a brief EDA at the beginning to Type III
ELMy and ELM-free alternating H-mode.
Apr 21 1999 12:17:19:077PM990421011Joseph SnipesShot 11:Good shot. RF power up to 2.4 MW throughout most of the pulse.
Ratty H-mode similar to shot 10.
Apr 21 1999 12:35:08:763PM990421011Joseph SnipesShot 12: Raised nl04 programming to 1.4 x 10^20 m^-2. Reduced prepuff to 14 msec
duration. No chance to run the shot. A water pipe burst on the
cooling for one of the RF transmitters and the RF power room area is
flooded. End of the run.
Apr 21 1999 01:52:45:513PM990421011Joseph SnipesThe machine ran rather well. The RF ran O.K. with up to 2.5 MW for 0.5 sec or
so. However, they had problems tuning and a cooling water pipe
burst on one of the RF transmitters flooding the RF area of the power room and
ending the run at about 12:30 pm. By analyzing the fast magnetic pick-up coil
signals, I noticed that the RF beat frequency had shifted to 600 kHz rather
than its usual 500 kHz. After the run, Fridberg and I checked and found that
indeed, the D port frequency had been inadvertently set to 80.6 MHz instead of
its usual 80.5 MHz. It has now been reset to 80.5 MHz for tomorrow.

Engineering Operator Comments
ShotTimeTypeStatusComment
109:19:16:687AMTestOkEF3 PLC controled test/ OK
209:32:29:840AMPlasmaOkno faults/plasma
309:48:56:450AMPlasmaOkno faults/plasma
410:06:55:093AMPlasmaOkno faults/plasma
510:24:44:093AMPlasmaOkno faults/plasma
610:46:09:903AMPlasmaOkno faults/plasma
711:03:18:140AMPlasmaBadno pulse Igor problem
811:20:48:920AMPlasmaBadigor /PLC sync problem/no EF1u,l no TF no OH1
911:34:29:670AMPlasmaOkno faults/plasma
1011:57:41:497AMPlasmaOkno faults/plasma
1112:13:22:903PMPlasmaOkno faults/plasma