Alcator C-Mod Run 990910 Information

Back to runs

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 1-23)

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

Engineering Operator Run Comment
RF Conditioning/Snipes, Silva

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Physics Operator Summaries
Entered: Jul 7 2004 04:37:09:253PM
Author: To Be Determined
Run Plan for 990910 RF Conditioning

Session Leader: Steve Wukitch
Physics Operator: Joseph Snipes

The run is scheduled to start at 9:00 and end at 17:00. The run will continue
RF conditioning from yesterday with standard 1 MA, 5.2 T plasmas with nl04 = 1
x 10^20 m^-2.

Engineering setup:

Two hours ECDC in D2 prior to run, finishing at least 1 hour before run.

Setup power supplies from 990909010
Gas setup - fill B-top with 6 psi of D2 Hybrid enabled
fill B-side lower with 1 psi of Ar Hybrid DISABLED
fill B-side upper with 6 psi of H2 Hybrid DISABLED
fill C-side with 30 psi of D2 Hybrid enabled
J-bottom pumped out Hybrid DISABLED

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

Summary:
The machine ran very well today with no engineering problems. The RF ran O.K.
as well. Shot 1 had a nice long EDA H-mode with 1 MW of D port RF only. Then,
there were many other shots with brief H-modes with either J3, J4, or D in
combination. Impurities from the J port antenna were a problem, leading to a
number of RF induced disruptions. There were also some impurity injections
early in the discharge, one of which led to an early disruption. There were a
few fizzles in the middle of the day following a long runaway shot (shot 12).
Finally, an EF4 tweak made the current rises reliable again. It was a good RF
conditioning run where I think the RF guys learned a lot.

Shot,Duration(s),Ipmax(MA) Shot,Duration(s),Ipmax
1 1.870 0.987 2 1.870 0.977
3 1.870 0.977 4 0.817 1.018
5 1.890 0.977 6 0.490 1.003
7 1.870 0.977 8 1.198 1.029
9 1.870 0.977 10 1.186 0.987
11 0.893 1.044 12 0.969 1.054
13 0.000 0.041 14 0.870 1.029
15 0.000 0.041 16 1.870 0.977
17 0.788 1.039 18 1.890 0.977
19 1.880 0.977 20 1.880 0.974
21 1.870 0.977 22 1.870 0.987
23 1.870 0.987
Finished summary for 990910 Total of 23 shots.
23 shots. 21 plasmas. 2 fizzles. 0 duds.

Shot 1: Loaded 990909010. Run delayed until 10:00 am to repair an arc in one
of the RF transmitters. Good shot. Nice long EDA H-mode 0.82 -
1.25 s. D port antenna at 1 MW.
Shot 2: Repeat. Good shot. Now with J3 and J4 instead of D port. PRF = 0.8
MW. Only a very brief H-mode, then some dithering. Large impurity
injections at 0.83, 0.9 and 0.94 s during RF.
Shot 3: Enabled Ar gas puff at 0.3 sec for 25 ms. NINJA puffing of He
starting at 0.2 s for 0.1 s duration. D port transmitter breaking
down due to humid air in its cavity, so we will not be able to use it
today. Good shot. Up to 1.4 MW out of J port, no H-mode, just
dithering.
Shot 4: Repeat. Disrupted at 0.81 s after a large impurity injection during
the RF. Radiated power begins to increase at 0.77 s apparently coming
from the RF antenna heating up. J port up to 1.5 MW.
Shot 5: Try again. Good shot. Two ELM-free H-modes between 1 - 1.2 s.
RF up to 1.3 MW out of J port.
Shot 6: Increased Br0 from 0.5 mT to 1 mT to correct for the Br drift at
breakdown. Current rise looks fine. Disrupted at 0.5 s apparently
due to a natural impurity injection.
Shot 7: Reduced RCUR and increased CLEARIN before 0.5 sec to try to increase
the gaps a bit to see if the small gaps resulted in the impurity
injection on shot 6. Good shot. H-mode 0.95 - 1.1 s. PRF = 1.2 MW.
Shot 8: Reduced Br0 by 0.5 mT back to 0.5 mT from 1 mT. Increased CLEARIN
during the current rise to increase the inner gap a bit. Good shot.
Disrupted at 1.18 s with increasing Prad throughout the RF pulse.
No H-mode.
Shot 9: Good shot. PRF = 1.2 MW. No H-mode. Impurity injection at 0.25 s
Some dithering.
Shot 10: No changes. Good shot. Disrupted at 1.18 s just before RF turns off.
No H-mode. Impurities apparently burning off of the J port antenna.
Locked mode at 1.17 s just before the disruption. PRF up to 1.5 MW.
Shot 11: No changes. Disrupted at 0.9 s apparently due to RF generated
impurities again. No H-mode. J port PRF = 1.5 MW.
Shot 12: Hard x rays from 0.025 s. Fill pressure looks about the same. Still,
I'll increase the pre-puff for the next shot to be sure. Nonetheless,
the plasma continued until 0.96 s when it disrupted due to RF
generated impurities again. PRF = 1.2 MW.
Shot 13: Increased pre-puff from 16 ms to 19 ms duration. Fizzle!
Shot 14: Increased EF4 current from -1275 to -1290 A at breakdown. Disrupted
at 0.86 s during RF apparently due to RF generated impurities.
PRF = 1.3 MW.
Shot 15: Reduced EF4 current again now to -1270 A from -1290 A. Increased
pre-puff from 19 ms to 20 ms duration to further reduce some small
remaining hard x rays. Fizzle!
Shot 16: Increased EF4 current again to -1285 A from -1270 A. Good shot.
H-mode from 1.02 - 1.25 s. PRF over 2 MW with D, J3, and J4 on.
Shot 17: No changes. Disrupted at 0.78 s during J4 RF with only 0.6 MW due to
increased impurities.
Shot 18: No changes. Good shot. Several short H-modes from 1.05 - 1.3 s
during D port and J4 RF up to 1.5 MW.
Shot 19: Good shot. Two H-modes from 1.05 - 1.3 s with 1.8 MW of RF from J3,
J4, and D port.
Shot 20: Repeat. Good shot. Impurity injections early at 0.22 and 0.32 s.
H-modes from 1.05 - 1.3 s. PRF = 1.6 MW out of D and J4.
Shot 21: Repeat. Good shot. Nice EDA H-mode from 1.07 - 1.3 s with D port RF
up to 1 MW. J3 gets up to 0.4 MW but switches off at 1 s.
Shot 22: Repeat. Good shot. Two H-modes from 0.59 - 0.88 s mostly with D
port, at 1 MW plus a short phase with J3 and J4 up to a total of
1.5 MW.
Shot 23: Repeat. Good shot with two H-modes from 0.7 - 1.1 s.


Session Leader Comments

Physics Operator Comments
Sep 10 1999 09:26:43:763AM990910001Joseph SnipesRun Plan for 990910 RF Conditioning

Session Leader: Steve Wukitch
Physics Operator: Joseph Snipes

The run is scheduled to start at 9:00 and end at 17:00. The run will continue
RF conditioning from yesterday with standard 1 MA, 5.2 T plasmas with nl04 = 1
x 10^20 m^-2.

Engineering setup:

Two hours ECDC in D2 prior to run, finishing at least 1 hour before run.

Setup power supplies from 990909010
Gas setup - fill B-top with 6 psi of D2 Hybrid enabled
fill B-side lower with 1 psi of Ar Hybrid DISABLED
fill B-side upper with 6 psi of H2 Hybrid DISABLED
fill C-side with 30 psi of D2 Hybrid enabled
J-bottom pumped out Hybrid DISABLED

The following gate valves should be enabled, assuming no vacuum problems:
ECE, VUV, PCI
Sep 10 1999 10:36:25:107AM990910001Joseph SnipesShot 1: Loaded 990909010. Run delayed until 10:00 am to repair an arc in one
of the RF transmitters. Good shot. Nice long EDA H-mode 0.82 - 1.25 s.
D port antenna at 1 MW.
Sep 10 1999 10:37:11:450AM990910002Joseph SnipesShot 2: Repeat. Good shot. Now with J3 and J4 instead of D port. PRF = 0.8 MW
Only a very brief H-mode, then some dithering. Large impurity
injections at 0.83, 0.9, and 0.94 s.

Sep 10 1999 10:53:27:467AM990910003Joseph SnipesShot 3: Enabled Ar gas puff at 0.3 sec for 25 ms. NINJA puffing of He starting
at 0.2 s for 0.1 s duration. D port transmitter breaking down due to
humid air in its cavity, so we will not be able to use it today.
Good shot. Up to 1.4 MW out of J port, no H-mode, just dithering.
Sep 10 1999 11:17:49:607AM990910004Joseph SnipesShot 4: Repeat. Disrupted at 0.81 s after a large impurity injection during
the RF. Radiated power begins to increase at 0.77 s apparently coming
from the RF antenna heating up. J port up to 1.5 MW.
Sep 10 1999 11:27:23:810AM990910005Joseph SnipesShot 5: Try again. Good shot. Two ELM-free H-modes between 1 - 1.2 s.
RF up to 1.3 MW out of J port.
Sep 10 1999 11:44:35:903AM990910006Joseph SnipesShot 6: Increased Br0 from 0.5 mT to 1 mT to correct for the Br drift at
breakdown. Current rise looks fine. Disrupted at 0.5 s apparently due
to a natural impurity injection.
Sep 10 1999 11:55:26:340AM990910007Joseph SnipesShot 7: Reduced RCUR and increased CLEARIN before 0.5 sec to try to increase
the gaps a bit to see if the small gaps resulted in the impurity
injection on shot 6. Good shot. H-mode 0.95 - 1.1 s. PRF = 1.2 MW.
Sep 10 1999 12:15:24:170PM990910008Joseph SnipesShot 8: Reduced Br0 by 0.5 mT back to 0.5 mT from 1 mT. Increased CLEARIN
during the current rise to increase the inner gap a bit. Good shot.
Disrupted at 1.18 s with increasing Prad throughout the RF pulse.
No H-mode.
Sep 10 1999 12:40:46:903PM990910009Joseph SnipesShot 9: Good shot. PRF = 1.2 MW. No H-mode. Impurity injection at 0.25 s
Some dithering.
Sep 10 1999 01:09:42:547PM990910010Joseph SnipesShot 10: No changes. Good shot. Disrupted at 1.18 s just before RF turns off.
No H-mode. Impurities apparently burning off of the J port antenna.
Locked mode at 1.17 s just before the disruption. PRF up to 1.5 MW.
Sep 10 1999 01:12:22:717PM990910011Joseph SnipesShot 11: No changes. Disrupted at 0.9 s apparently due to RF generated
impurities again. No H-mode. J port PRF = 1.5 MW.
Sep 10 1999 01:34:26:810PM990910012Joseph SnipesShot 12: Hard x rays from 0.025 s. Fill pressure looks about the same. Still,
I'll increase the pre-puff for the next shot to be sure. Nonetheless,
the plasma continued until 0.96 s when it disrupted due to RF generated
impurities again. PRF = 1.2 MW.
Sep 10 1999 01:54:06:030PM990910013Joseph SnipesShot 13: Increased pre-puff from 16 ms to 19 ms duration. Fizzle!
Sep 10 1999 02:34:51:810PM990910014Joseph SnipesShot 14: Increased EF4 current from -1275 to -1290 A at breakdown. Disrupted
at 0.86 s during RF apparently due to RF generated impurities.
PRF = 1.3 MW.
Sep 10 1999 02:40:59:750PM990910015Joseph SnipesShot 15: Reduced EF4 current again now to -1270 A from -1290 A. Increased
pre-puff from 19 ms to 20 ms duration to further reduce some small
remaining hard x rays. Fizzle!
Sep 10 1999 02:58:41:843PM990910016Joseph SnipesShot 16: Increased EF4 current again to -1285 A from -1270 A. Good shot.
H-mode from 1.02 - 1.25 s. PRF over 2 MW with D, J3, and J4 on.

Sep 10 1999 03:16:22:607PM990910017Joseph SnipesShot 17: No changes. Disrupted at 0.78 s during J4 RF with only 0.6 MW due to
increased impurities.
Sep 10 1999 03:28:11:920PM990910018Joseph SnipesShot 18: No changes. Good shot. Several short H-modes from 1.05 - 1.3 s during
D port and J4 RF up to 1.5 MW.
Sep 10 1999 03:52:19:263PM990910019Joseph SnipesShot 19: Good shot. Two H-modes from 1.05 - 1.3 s with 1.8 MW of RF from J3, J4,
and D port.
Sep 10 1999 04:05:09:797PM990910020Joseph SnipesShot 20: Repeat. Good shot. Impurity injections early at 0.22 and 0.32 s.
H-modes from 1.05 - 1.3 s. PRF = 1.6 MW out of D and J4.
Sep 10 1999 04:22:33:170PM990910021Joseph SnipesShot 21: Repeat. Good shot. Nice EDA H-mode from 1.07 - 1.3 s with D port RF
up to 1 MW. J3 gets up to 0.4 MW but switches off at 1 s.
Sep 10 1999 04:41:39:750PM990910022Joseph SnipesShot 22: Repeat. Good shot. Two H-modes from 0.59 - 0.88 s mostly with D port,
at 1 MW plus a short phase with J3 and J4 up to a total of 1.5 MW.
Sep 10 1999 04:57:07:637PM990910023Joseph SnipesShot 23: Repeat. Good shot with two H-modes from 0.7 - 1.1 s.
Sep 10 1999 04:58:26:763PM990910023Joseph Snipes Shot,Duration(s),Ipmax(MA) Shot,Duration(s),Ipmax
1 1.870 0.987 2 1.870 0.977
3 1.870 0.977 4 0.817 1.018
5 1.890 0.977 6 0.490 1.003
7 1.870 0.977 8 1.198 1.029
9 1.870 0.977 10 1.186 0.987
11 0.893 1.044 12 0.969 1.054
13 0.000 0.041 14 0.870 1.029
15 0.000 0.041 16 1.870 0.977
17 0.788 1.039 18 1.890 0.977
19 1.880 0.977 20 1.880 0.974
21 1.870 0.977 22 1.870 0.987
23 1.870 0.987
Finished summary for 990910 Total of 23 shots.
23 shots. 21 plasmas. 2 fizzles. 0 duds.
Sep 10 1999 05:00:33:200PM990910023Joseph SnipesSummary:
The machine ran very well today with no engineering problems. The RF ran O.K.
as well. Shot 1 had a nice long EDA H-mode with 1 MW of D port RF only. Then,
there were many other shots with brief H-modes with either J3, J4, or D in
combination. Impurities from the J port antenna were a problem, leading to a
number of RF induced disruptions. There were also some impurity injections
early in the discharge, one of which led to an early disruption. There were a
few fizzles in the middle of the day following a long runaway shot (shot 12).
Finally, an EF4 tweak made the current rises reliable again. It was a good RF
conditioning run where I think the RF guys learned a lot.

Engineering Operator Comments
ShotTimeTypeStatusComment
110:03:39:433AMPlasmaOk10:03 shot#1/no faults/plasma
210:24:38:840AMPlasmaOkNo Faults/ Plasma
310:43:45:343AMPlasmaOk(null)
411:00:33:920AMPlasmaOk(null)
511:17:35:700AMPlasmaOk(null)
611:34:33:093AMPlasmaOk(null)
711:48:10:967AMPlasmaOk(null)
812:08:53:310PMPlasmaOk(null)
912:23:54:873PMPlasmaOk(null)
1012:49:08:937PMPlasmaOk(null)
1101:05:36:763PMPlasmaOk(null)
1201:24:18:717PMPlasmaOk(null)
1301:43:34:343PMPlasmaOk(null)
1402:19:51:780PMPlasmaOk(null)
1502:39:32:000PMPlasmaOk(null)
1602:52:31:653PMPlasmaOk(null)
1703:10:14:717PMPlasmaOk(null)
1803:23:25:280PMPlasmaOk(null)
1903:43:04:420PMPlasmaOk(null)
2003:59:41:000PMPlasmaOk(null)
2104:17:40:437PMPlasmaOk(null)
2204:35:06:450PMPlasmaOk(null)
2304:53:12:593PMPlasmaOk(null)