Alcator C-Mod Run 1000505 Information

Back to runs

Miniproposals
Miniproposal:265
Date Filed: 4/7/2000
Title:CXRS Commissioning
First Author:E.C. Eisner
Session Leader:E.C. Eisner (shots 24-26)
Miniproposal:266
Date Filed: 4/1/2000
Title:DNB Conditioning
First Author:Bill Rowan
Session Leader:E.C. Eisner (shots 1-23)

Operators
Session leader(s):E.C. Eisner,E.C. Eisner
Physics operator(s):Joseph Snipes
Engineering operator(s): Unknown

Engineering Operator Run Comment
Run Plan for Friday, 05 May 2000. MP#266 Beam Conditioning, MP#265 CXRS

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Physics Operator Summaries
Entered: Jul 7 2004 04:37:10:490PM
Author: To Be Determined
Engineering Setup and Run Plan for Friday, 05 May 2000.

Run to start at 09:00 and end at 17:00.

MP # 266 Beam Conditioning
MP # 265 CXRS Commissioning

SL: Ned Eisner
PO: Joseph Snipes

Engineering setup:
-------------------
ECDC overnight in D2, turn off 2 hours before run

Power system setup as on 1000504011
Gas setup - fill B-top with 6 psi of D2 Hybrid enabled
fill B-side lower with 1 psi of Ar Hybrid enabled
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:
VUV and ECE

Run Plan:
---------

Start plasma operations from a reload of shot 1000504011
and proceed with DNB conditioning and CXRS commissioning.

Summary: It was a good run. The machine ran very well. The computers ran
reasonably well and the DNB and ICRF ran well. We exceeded 5 MW on the last
two plasma shots 22 and 23, but the J-port antenna did not heat very well.
There were large broadband MHD fluctuations during the J-port ICRF pulses, much
larger than during D and E port ICRF pulses. Lithium pellets were fired into
the end of most of the shots as well. There were 20 full length plasmas, 3
fizzles and two gas tests at the end.

Shot 1: Copied shot 1000504011. Good shot. Long EDA H-mode with over 2 MW of
ICRF power. ECE GPC was switched off.
Shot 2: Breakdown gas pressure seems a bit low, so I am increasing the prepuff
from 12 ms duration to 17 ms duration. Good shot. Long EDA H-mode
with about 2.5 MW of ICRF power.
Shot 3: Raised prepuff again to 20 ms duration. Bz and Br were a bit higher
yesterday, so we may have to raise them again but I'll try the prefill
first. Good shot. Nice long EDA H-mode with 2.5 MW of ICRF power.
The increased prefill appears to have improved the current rise
without changing Br or Bz.
Shot 4: Decreased RCUR by 2 mm to increase the outer gap at Boivin's request
to change the RF coupling. Good shot. RF coupling improved a bit.
Long EDA H-mode with 2.6 MW of ICRF power.
Shot 5: Reduced RCUR again by 2 mm to further improve RF coupling. Also
increased CLEARIN to keep the left gap constant. The right
gap went too far to 1.5 cm. RF coupling not as good. DNB did not
fire.
Shot 6: Increased RCUR by 1 mm to reduce the right gap. Also reduced CLEARIN
by about 1 mm. Lithium pellet injector enabled for this shot to fire
at 1.4 sec. Good shot. Long EDA H-mode with 2.5 MW of ICRF. Li
pellet did fire at 1.4 sec.
Shot 7: Increased Br0 offset from -0.5 mT to 0. Good shot.
Shot 8: Increased ZCUR by 5 mm for edge Thomson. Good shot. Long EDA H-mode
with 2.5 MW of ICRF power. J port power slowly increasing as well.
Shot 9: Repeat. Good shot. Long EDA H-mode. Now have 1.5 MW out of J port.
Shot 10: Repeat. Fizzle! It seems Br0 has been drifting upward shot-to-shot.
Shot 11: Set Br0 to -0.5 mT again. Two EDA H-modes. Up to 2 MW out of J-port,
yet still not H-mode during J-port ICRF pulse.
Shot 12: Repeat with Li pellet at 1.45 sec instead of 1.4 sec. Fizzle!
Shot 13: Reduced prepuff by 2 msec to 18 msec duration. Reduced Br0 to -1 mT.
Good shot. D and E port up to 2.8 MW and J-port up to 2 MW of ICRF.
Broadband MHD fluctuations increase enormously during J-port ICRF
pulse rather than D and E pulses perhaps indicating where the power
is going.
Shot 14: Inserted 8 kA TF ramp from 0.8 to 0.9 sec for ECE sweep during the
H-mode. Reduced EF4 current by 10 A to -1390 A. Good shot.
Shot 15: Repeat. Fizzle!
Shot 16: Reduce Br0 to -0.5 mT and try again. Good shot. Still not a good
current rise though.
Shot 17: Wolfe suggested to make Bz more positive according to Ian's current
over Bz curve. So, I've increased EF4 current from -1300 A to -1280 A
at breakdown. Good shot. 2.5 MW from D&E and 2 MW from J later in
the shot. Li pellet at 1.45 sec again.
Shot 18: Repeat. Good shot.
Shot 19: Repeat. Good shot.
Shot 20: Move ZCUR back down by 5 mm to -17 mm to check if RF coupling
improves. Good shot.
Shot 21: Increase RCUR by 1 mm to reduce the outer gap to about 1 cm to improve
ICRF coupling. Good shot until it disrupted at 1.3 sec.
Shot 22: Removed TF sweep from 0.8 to 0.9 sec to check the effect on RF
coupling at Rejean's request. Good shot. Combined D, E, and J-port
ICRF to over 5 MW very briefly. H-modes rather ratty looking though.
Shot 23: Repeat with attempt to improve ICRF tuning. Good shot.
Shot 24: Gas test shot with no power supplies except for the DNB.
Shot 25: Gas test shot with no power supplies except for the DNB.


Session Leader Comments
May 5 2000 08:56:53:890AME.C. EisnerDNB and CXRS comissioning
May 5 2000 06:18:25:327PM1000505024E.C. EisnerGas only pulse with beam on
May 5 2000 06:18:40:280PM1000505025E.C. EisnerGas only pulse with beam on
May 5 2000 06:18:50:013PM1000505026E.C. EisnerGas only pulse with beam on

Physics Operator Comments
May 5 2000 09:14:54:250AM1000505001Joseph SnipesEngineering Setup and Run Plan for Friday, 05 May 2000.

Run to start at 09:00 and end at 17:00.

MP # 266 Beam Conditioning
MP # 265 CXRS Commissioning

SL: Ned Eisner
PO: Joseph Snipes

Engineering setup:
-------------------
ECDC overnight in D2, turn off 2 hours before run

Power system setup as on 1000504011

Gas setup - fill B-top with 6 psi of D2 Hybrid enabled
fill B-side lower with 1 psi of Ar Hybrid enabled
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:
VUV and ECE

Run Plan:
---------

Start plasma operations from a reload of shot 1000504011
and proceed with DNB conditioning and CXRS commissioning.
May 5 2000 09:16:19:997AM1000505001Joseph SnipesShot 1: Copied shot 1000504011. Good shot. Long EDA H-mode with over 2 MW of
ICRF power. ECE GPC was switched off.
May 5 2000 09:31:35:577AM1000505002Joseph SnipesShot 2: Breakdown gas pressure seems a bit low, so I am increasing the prepuff
from 12 ms duration to 17 ms duration. Good shot. Long EDA H-mode
with about 2.5 MW of ICRF power.
May 5 2000 10:02:37:513AM1000505003Joseph SnipesShot 3: Raised prepuff again to 20 ms duration. Bz and Br were a bit higher
yesterday, so we may have to raise them again but I'll try the prefill
first. Good shot. Nice long EDA H-mode with 2.5 MW of ICRF power.
The increased prefill appears to have improved the current rise without
changing the Br or Bz.

May 5 2000 10:27:47:513AM1000505004Joseph SnipesShot 4: Decreased RCUR by 2 mm to increase the outer gap at Boivin's request
to change the RF coupling. Good shot. RF coupling improved a bit.
Long EDA H-mode with 2.6 MW of ICRF power.


May 5 2000 10:49:23:937AM1000505005Joseph SnipesShot 5: Reduced RCUR again by 2 mm to further improve RF coupling. Also
increased CLEARIN to keep the left gap constant. The right
gap went too far to 1.5 cm. RF coupling not as good. DNB did not fire.



May 5 2000 11:05:43:700AM1000505006Joseph SnipesShot 6: Increased RCUR by 1 mm to reduce the right gap. Also reduced CLEARIN
by about 1 mm. Lithium pellet injector enabled for this shot to fire
at 1.4 sec. Good shot. Long EDA H-mode with 2.5 MW of ICRF. Li
pellet did fire at 1.4 sec.


May 5 2000 11:55:21:030AM1000505007Joseph SnipesShot 7: Increased Br0 offset from -0.5 mT to 0. Good shot.

May 5 2000 11:58:32:293AM1000505008Joseph SnipesShot 8: Increased ZCUR by 5 mm for edge Thomson. Good shot. Long EDA H-mode
with 2.5 MW of ICRF power. J port power slowly increasing as well.
May 5 2000 12:31:57:263PM1000505009Joseph SnipesShot 9: Repeat. Good shot. Long EDA H-mode. Now have 1.5 MW out of J port.
May 5 2000 12:37:50:860PM1000505010Joseph SnipesShot 10: Repeat. Fizzle! It seems Br0 has been drifting upward shot-to-shot.
May 5 2000 12:58:21:543PM1000505011Joseph SnipesShot 11: Set Br0 to -0.5 mT again. Two EDA H-modes. Up to 2 MW out of J-port,
yet still not H-mode during J-port ICRF pulse.
May 5 2000 01:15:22:780PM1000505012Joseph SnipesShot 12: Repeat with Li pellet at 1.45 sec instead of 1.4 sec. Fizzle!
May 5 2000 01:42:48:340PM1000505013Joseph SnipesShot 13: Reduced prepuff by 2 msec to 18 msec duration. Reduced Br0 to -1 mT.
Good shot. D and E port up to 2.8 MW and J-port up to 2 MW of ICRF.
Broadband MHD fluctuations increase enormously during J-port ICRF
pulse rather than D and E pulses perhaps indicating where the power
is going.

May 5 2000 02:51:15:920PM1000505014Joseph SnipesShot 14: Inserted 8 kA TF ramp from 0.8 to 0.9 sec for ECE sweep during the
H-mode. Reduced EF4 current by 10 A to -1300 A.
May 5 2000 02:16:38:327PM1000505015Joseph SnipesShot 15: Repeat. Fizzle!
May 5 2000 02:45:12:123PM1000505016Joseph SnipesShot 16: Reduce Br0 to -0.5 mT and try again. Good shot. Still not a good
current rise though.
May 5 2000 03:02:38:513PM1000505017Joseph SnipesShot 17: Wolfe suggested to make Bz more positive according to Ian's current
over Bz curve. So, I've increased EF4 current from -1300 A to -1280 A
at breakdown. Good shot. 2.5 MW from D&E and 2 MW from J later in
the shot. Li pellet at 1.45 sec again.
May 5 2000 03:20:18:793PM1000505018Joseph SnipesShot 18: Repeat. Good shot.
May 5 2000 04:02:48:327PM1000505019Joseph SnipesShot 19: Repeat. Good shot.
May 5 2000 04:05:51:653PM1000505020Joseph SnipesShot 20: Move ZCUR back down by 5 mm to -17 mm to check if RF coupling
improves. Good shot.
May 5 2000 04:27:24:997PM1000505021Joseph SnipesShot 21: Increase RCUR by 1 mm to reduce the outer gap to about 1 cm to improve
ICRF coupling. Good shot until it disrupted at 1.3 sec.

May 5 2000 04:45:41:717PM1000505022Joseph SnipesShot 22: Removed TF sweep from 0.8 to 0.9 sec to check the effect on RF
coupling at Rejean's request. Good shot. Combined D, E, and J-port
ICRF to over 5 MW very briefly. H-modes rather ratty looking though.

May 5 2000 05:24:21:340PM1000505023Joseph SnipesShot 23: Repeat with attempt to improve ICRF tuning. Good shot.
May 5 2000 05:24:33:247PM1000505024Joseph SnipesShot 24: Gas test shot with no power supplies except for the DNB.
May 5 2000 05:26:18:793PM1000505024Joseph SnipesSummary: It was a good run. The machine ran very well. The computers ran
reasonably well and the DNB and ICRF ran well. We exceeded 5 MW on the last
two plasma shots 22 and 23, but the J-port antenna did not heat very well.
There were large broadband MHD fluctuations during the J-port ICRF pulses, much
larger than during D and E port ICRF pulses. Lithium pellets were fired into
the end of most of the shots as well. There were 20 full length plasmas, 3
fizzles and two gas tests at the end.

Engineering Operator Comments
ShotTimeTypeStatusComment
108:59:39:373AMPlasmaOk
209:22:31:373AMPlasmaOk
309:49:01:390AMPlasmaOk
410:14:24:123AMPlasmaOk
510:34:56:793AMPlasmaOk
610:57:57:373AMPlasmaOk
711:19:06:407AMPlasmaOk
811:52:16:077AMPlasmaOk
912:12:24:593PMPlasmaOk
1012:32:37:200PMPlasmaOk
1112:51:11:500PMPlasmaOk
1201:13:48:187PMPlasmaOk
1301:28:27:890PMPlasmaOk
1401:51:20:407PMPlasmaOk
1502:13:19:513PMPlasmaOk
1602:30:10:110PMPlasmaOk
1702:52:42:873PMPlasmaOk
1803:13:27:763PMPlasmaOk
1903:34:56:437PMPlasmaOk
2003:55:53:657PMPlasmaOk
2104:16:46:500PMPlasmaOk
2204:38:05:950PMPlasmaOk
2304:58:17:560PMPlasmaOk
2405:15:37:200PMTestOk
2505:26:39:187PMTestOk
2605:38:01:107PMTestOk