Alcator C-Mod Run 960827 Information

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Miniproposals
Miniproposal:133
Date Filed:12/8/1995
Title:Boronization of Alcator C-Mod
First Author:Jim Terry
Session Leader:Yuichi Takase (shots 20-20)
Miniproposal:159a
Date Filed: 7/29/1996
Title:Restart Operation: August 1996
First Author:Steve Wolfe
Session Leader:Yuichi Takase (shots 1-20)

Operators
Session leader(s):Yuichi Takase,Yuichi Takase
Physics operator(s):Joseph Snipes
Engineering operator(s):Frank Silva

Engineering Operator Run Comment
mp159,133/takase,snipe

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:16:320PM
Author: To Be Determined
1st part of 960827
Run summary 960827 (Part 1)

SL: Takase
PO: Snipes
EO: Silva

MP159 RF Conditioning
MP133 Post-boron fiducials

Run Plan:

Conditioning of E-port antenna at low density
in an attempt to determine whether the poor
heating we have been seeing is due to high
H concentration or insufficient antenna
conditioning.

D-port antenna is not available today (fixing
water leak in the transmitter).

In the afternoon (circumstances permitting)
the run will be handed over to
MP156A 1.5MA 8 Tesla or MP161 Low triangularity.

Run Summary:

2nd overnight ECDC boronization (11 hrs. 1300 Angstroms of boron
deposited) of the campaign last night, followed by 2hrs. He ECDC.

We have made some progress in RF conditioning. H-mode quality
seems to be improving. There was an RF interference problem on
EF4, caused by up to 5kW of RF power transmitted back from the
D-port antenna to the power room. The water leak have been fixed
and the transmitter should be connected to the antenna tonight.

Shot

01 test TF scanner test
02 test OH test
03 pla* Nice shot, nel=1.0, P_E=1.75MW
04 dud
05 fiz
06 fiz
07 pla disr @ 0.58s
08 dud
09 pla disr @ 0.54s, inj @ 0.43s
10 dud
11 dud
12 dud
13 dud
fixed \rf_power_rad
14 pla* disr @ 0.79s (EF4), weak H-mode @ 0.66s
long delay to fix EF4
15 test EF4 test
16 test EF4 test
17 test EF4 test
18 dud
19 fiz
20 pla* lost EF4 (RF pickup from disconnected D-port transmission line)
nel=0.9 + H-mode, Te0(peak)=4keV, Ti0=2keV, W_EFIT=80kJ, P_E=1.5MW,
3.e12 neuts/s


Physics Operator Summaries
Entered: Jul 7 2004 04:36:56:677PM
Author: To Be Determined
MP159 RF Conditioning
Session Leader: Yuichi Takase
Physics Operator: Joseph Snipes
Engineer in Charge: Frank Silva

After overnight boronization (1300 A) and 1 hr 45 min He ECDC this morning, we
will start with setup for shot 960823016 after a scanner test shot and an OH
test shot. The idea will be to run standard discharges at 5.4 T and 0.8 MA to
first do RF conditioning.

The goals were not exactly accomplished. Only 5 plasmas were made and ICRF
was coupled up to about 1.5 MW on transmitter 2. Transmitter 1 was wide open
under repair. Fuses were blown on EF4 on shots 14 and 20. The 3 hour delay
after shot 14 to replace fuses also resulted in large changes in the hybrid
offsets perhaps due to changes in the hybrid wiring during the break. The
Br offset was at about 6.5 mT to get plasmas by the end of the day. EF4
currents also had to be reduced to get the vertical field right. The last
setting that worked was at -1375 A at breakdown. It appears that the open
RF transmission line was transmitting reflected power during the H-mode back
to the power room and interfering with the EF4 control circuit, leading to
the EF4 failures.

Shot 1: Scanner test.
Shot 2: OH test
Shot 3: Copied shot 960823016, increased density to 1.0 x 10^20 m^-2. Moved RXL
gain step down from 1.2 to 1.32 sec. Set pre-puff to 14 msec. Moved
RXL in by 5 mm and ZXL up a tad to -0.01 m. Good plasma all the way
down lasting to 1.65 sec.
Shot 4: Reduced nl04 to 9 x 10^19 m^-2. Moved ZCUR down from -0.005 to -0.012
m during the flattop. Dud!
Shot 5: Br offset moved down 0.5 mT to 2.0 mT. Fizzle!
Shot 6: Br offset changed to 3.0 mT. Fizzle.
Shot 7: Br offset changed to 2.5 mT. Got plasma. Disrupted at 0.55 sec.
OH2 fault accompanied by a moly injection.
Shot 8: Repeat. Dud!
Shot 9: Repeat. Got plasma. Disrupted at 0.54. Another moly injection.
Looks like RXL is way off.
Shot 10:RXL set to 0 during the flattop from 0.01 m. Dud!
Shot 11:Reloaded shot 960823019. Changed RXL gain to extend out to 1.32 sec,
then step down at 1.4 sec. Density set to 9 x 10^19 m^-2. ZXL set
to -0.01 m. Pre-puff set to 14 msec. RXL left at +0.005 m. Dud.
Shot 12:Raised Br offset to 3 mT. Increased pre-puff to 15 msec. Dud.
Shot 13:Reloaded shot 960827003 segment 1 into segment 1. Dud.
Shot 14:EF4 current moved up from -1450 to -1425 to increase Bz by 2 mT.
Increased Br offset to 3 mT. Got plasma. EF4 failure. Disrupted
at 0.8 sec. Itsy bitsy H-mode from 0.66 to 0.71 sec. Long delay to
look into the EF4 and possible other power supply problems.
Shot 15:EF4 test shot
Shot 16:EF4 test shot
Shot 17:EF4 test shot
Shot 18:Changed gains on EF4 to step down at 0.248 instead of 0.492 so that
the change in gain on the EF2 by EF4 controller at 0.248 does not
fight EF4 so much. Dud!
Shot 19:Moved Ar puff to 0.3 - 0.344 sec. Previously, it started at
0.35 sec. Changed EF4 current to -1390 A and Br offset to 5 mT.
It appears that the coils became cold during the wait and the fields
changed. Fizzle!
Shot 20:Changed EF4 current to -1375 A and Br offset to 6.5 mT. Got plasma.
Disrupted at 0.9 sec. EF4 fuses blown again. Problems start
during RF pulse at the H-mode. H-mode from about 0.62 to 0.72 sec.
Wolfe proposes that the EF4 problems might be caused by RF pickup in
the power room from reflected power down the open transmission line
to transmitter 1.

Scorecard:
20 Shots
5 plasmas
3 fizzles
7 duds
5 test shots

Session Leader Comments
Aug 27 1996 09:20:19:470AMYuichi Takase1st part of 960827
SL: Takase
PO: Snipes
EO: Silva

MP159 RF Conditioning
MP133 Post-boron fiducials

Conditioning of E-port antenna at low density
in an attempt to determine whether the poor
heating we have been seeing is due to high
H concentration or insufficient antenna
conditioning.

D-port antenna is not available today (fixing
water leak in the transmitter).

In the afternoon (circumstances permitting)
the run will be handed over to
MP156A 1.5MA 8 Tesla or MP161 Low triangularity.

Aug 27 1996 09:26:34:610AMYuichi Takase2nd overnight ECDC boronization (11 hrs. 1300 Angstroms of boron
deposited) of the campaign last night, followed by 2hrs. He ECDC.

Aug 27 1996 09:27:52:090AM960827001Yuichi TakaseShot 001
TF scanner test

Aug 27 1996 09:28:30:960AM960827002Yuichi TakaseShot 002
OH test

Aug 27 1996 10:06:17:670AM960827003Yuichi TakaseShot 003 Plasma
nel=1.0 programmed.
nel=1.0, P_E=1.75MW.

Aug 27 1996 10:06:34:200AM960827003Yuichi TakaseShot 004 Dud

Aug 27 1996 10:07:32:550AM960827005Yuichi TakaseShot 005 Fizzle

Aug 27 1996 10:18:20:620AM960827006Yuichi TakaseShot 006 Fizzle

Aug 27 1996 10:44:18:780AM960827007Yuichi TakaseShot 007 plasma
disr @ 0.58s

Aug 27 1996 10:47:50:830AM960827008Yuichi TakaseShot 008 dud

Aug 27 1996 10:59:33:230AM960827009Yuichi TakaseShot 009 plasma
disr @ 0.54s, inj @ 0.43s

Aug 27 1996 11:57:30:710AM960827010Yuichi TakaseShot 010 dud

Aug 27 1996 11:57:39:160AM960827011Yuichi TakaseShot 011 dud

Aug 27 1996 11:57:47:690AM960827012Yuichi TakaseShot 012 dud

Aug 27 1996 11:57:55:270AM960827013Yuichi TakaseShot 013 dud

Aug 27 1996 03:09:27:200PM960827014Yuichi TakaseShot 014 plasma
disr @ 0.79s (EF4 problem)
weak H-mode @ 0.66s
\rf_power_rad signal fixed.

Aug 27 1996 03:09:56:110PM960827015Yuichi TakaseShot 015 EF4 test (after a long delay)

Aug 27 1996 03:30:56:120PM960827016Yuichi TakaseShot 016 another EF4 test

Aug 27 1996 03:42:25:260PM960827017Yuichi TakaseShot 017 yet another EF4 test

Aug 27 1996 04:01:54:850PM960827018Yuichi TakaseShot 018 dud

Aug 27 1996 06:12:17:890PM960827020Yuichi TakaseShot 020 plasma
lost EF4 (RF pickup from disconnected D-port transmission line)
nel=0.9 + H-mode, Te0(peak)=4keV, Ti0=2keV, W_EFIT=80kJ, P_E=1.5MW,
3.e12 neuts/s

Physics Operator Comments
Aug 27 1996 09:26:43:010AMJoseph SnipesMP159 RF Conditioning
Session Leader: Yuichi Takase
Physics Operator: Joseph Snipes
Engineer in Charge: Frank Silva

After overnight boronization (1300 A) and 1 hr 45 min He ECDC this morning, we
will start with setup for shot 960823016 after a scanner test shot and an OH
test shot. The idea will be to run standard discharges at 5.4 T and 0.8 MA to
first do RF conditioning.


Aug 27 1996 09:27:21:340AM960827001Joseph SnipesShot 1: Scanner test.

Aug 27 1996 09:27:39:690AM960827002Joseph SnipesShot 2: OH test. O.K.

Aug 27 1996 09:52:06:540AM960827003Joseph SnipesShot 3: Copied shot 960823016, increased density to 1.0 x 10^20 m^-2.
Moved RXL gain step down from 1.2 to 1.32 sec. Set pre-puff to
14 msec. Moved RXL in by 5 mm and ZXL up a tad to -0.01 m.
Good plasma all the way down lasting to 1.65 sec.

Aug 27 1996 09:52:40:240AM960827004Joseph SnipesShot 4: Reduced nl04 to 9 x 10^19 m^-2. Moved ZCUR down from -0.005 to -0.012
m during the flattop. Dud!


Aug 27 1996 10:13:52:510AM960827005Joseph SnipesShot 5: Br offset moved down 0.5 mT to 2.0 mT. Fizzle!

Aug 27 1996 10:36:52:740AM960827006Joseph SnipesShot 6: Br offset changed to 3.0 mT. Fizzle.


Aug 27 1996 10:38:29:080AM960827007Joseph SnipesShot 7: Br offset changed to 2.5 mT. Got plasma. Disrupted at 0.55 sec.
OH2 fault.

Aug 27 1996 10:46:13:800AM960827008Joseph SnipesShot 8: Repeat. Dud!

Aug 27 1996 11:35:32:130AM960827009Joseph SnipesShot 9: Repeat. Plasma. Disrupted at 0.54. Another moly injection.
Looks like RXL is way off.

Aug 27 1996 11:35:54:200AM960827010Joseph SnipesShot 10:RXL set to 0 during the flattop from 0.01 m. Dud!


Aug 27 1996 11:36:11:520AM960827011Joseph SnipesShot 11:Reloaded shot 960823019. Changed RXL gain to extend out to 1.32 sec,
then step down at 1.4 sec. Density set to 9 x 10^19 m^-2. ZXL set
to -0.01 m. Pre-puff set to 14 msec. RXL left at +0.005 m. Dud.


Aug 27 1996 12:24:07:720PM960827012Joseph SnipesShot 12:Raised Br offset to 3 mT. Increased pre-puff to 15 msec.
Dud.

Aug 27 1996 12:24:35:490PM960827013Joseph SnipesShot 13:Reloaded shot 960827003 segment 1 into segment 1. Dud.


Aug 27 1996 12:24:57:740PM960827014Joseph SnipesShot 14:EF4 current moved up from -1450 to -1425 to increase Bz by 2 mT.
Increased Br offset to 3 mT. Got plasma. EF4 failure. Disrupted
at 0.8 sec.


Aug 27 1996 12:36:53:570PM960827014Joseph SnipesShot 14:EF4 current moved up from -1450 to -1425 to increase Bz by 2 mT.
Increased Br offset to 3 mT. Got plasma. EF4 failure. Disrupted
at 0.8 sec. Itsy bitsy H-mode from 0.66 to 0.71 sec. Long delay to
look into the EF4 and possible other power supply problems.



Aug 27 1996 03:27:34:790PM960827015Joseph SnipesShot 15: EF4 test shot.

Aug 27 1996 03:27:58:300PM960827016Joseph SnipesShot 16: EF4 test shot.

Aug 27 1996 03:42:18:880PM960827017Joseph SnipesShot 17:EF4 test shot

Aug 27 1996 04:52:09:850PM960827018Joseph SnipesShot 18:Changed gains on EF4 to step down at 0.248 instead of 0.492 so that
the change in gain on the EF2 by EF4 controller at 0.248 does not
fight EF4 so much. Dud!


Aug 27 1996 04:52:31:710PM960827019Joseph SnipesShot 19:Moved Ar puff to 0.3 - 0.344 sec. Previously, it started at
0.35 sec. Changed EF4 current to -1390 A and Br offset to 5 mT.
It appears that the coils became cold during the wait and the fields
changed. Fizzle!


Aug 27 1996 05:46:32:520PM960827020Joseph SnipesShot 20:Changed EF4 current to -1375 A and Br offset to 6.5 mT. Got plasma.
Disrupted at 0.9 sec. EF4 fuses blown again. Problems start
during RF pulse at the H-mode. H-mode from about 0.62 to 0.72 sec.
Wolfe proposes that the EF4 problems might be caused by RF pickup in
the power room from reflected power down the open transmission line
to transmitter 1.


Aug 28 1996 07:33:36:990AM960827020Steve WolfeRun Plan for 960828
======================
MP 159 RF conditioning
MP 133 Post-boronization fiducials (piggyback)
and possibly:
MP 156A 1.5MA development
MP 161 Low triangularity

SL: Takase
PO: Wolfe
EO: Silva and Daigle

Engineering setup
-------------------
ECDC Overnight in Helium
ower systems setup as for 960827020; note: hybrid control on TF.
Gas setup = standard
A-side 20psi D2
B-top 5psi D2
B-side Lower 4psi Ar
Enable all for first shot (hybrid)

Engineering Operator Comments
ShotTimeTypeStatusComment
107:27:28:440AMTestOkscanner test
209:13:11:850AMTestOkoh 1, oh2u-l test
309:29:10:730AMTestOkplasma, 0930 start/ no faults
409:48:22:880AMTestOkno faults
510:05:51:150AMPlasmaOkno faults
610:16:36:310AMPlasmaOkno faults
710:26:07:150AMPlasmaOkcomm. fault oh2u-l/comm fault ef1u-l
810:39:36:170AMPlasmaOk
910:51:23:870AMPlasmaOk
1011:08:45:570AMPlasmaOk
1111:23:53:430AMPlasmaOk
1211:35:41:820AMPlasmaOk
1311:46:12:640AMPlasmaOk
1411:55:13:240AMPlasmaBadef4 fault
1503:06:16:000PMTestOk
1603:24:44:730PMTestOk
1703:40:19:870PMTestOk
1803:53:56:050PMPlasmaOk
1904:10:20:330PMPlasmaOk
2004:19:37:070PMPlasmaBadpppp