Alcator C-Mod Run 1030430 Information

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Miniproposals
Miniproposal:
Date Filed:
Title:
First Author:
Session Leader: Unknown (shots 1-25)

Operators
Session leader(s): Unknown
Physics operator(s):Joseph Snipes
Engineering operator(s):Bill Byford,Gary Dekow,Bill Parkin

Engineering Operator Run Comment
Machine Clean-up PO:Snipes; EO:Dekow/Byford/Parkin

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Physics Operator Summaries
Entered: Jul 7 2004 04:37:17:630PM
Author: To Be Determined
Run Plan for Tuesday, April 29, 2003
Physop: Snipes


Purpose: Clean-up, RF conditioning, diagnostic checkout

Engineering setup
_________________

ECDC in D2 overnight prior to run. 60C bake

Run starts at 9:00AM

Power systems as on 1030429024

Gas setup:
fill B-top with 6 psi of D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi of Ar Hybrid enabled (PG1)
fill B-side upper with 10 psi of D2 Hybrid DISABLED (PG2)
fill C-side with 30 psi of D2 Hybrid enabled (PG3)
ICRF: Transmitters 1 and 2 should be in Run On by 7:00 am.

Enable the ECE and DNB gate-valves, assuming no vacuum problems.

Summary: Overall, it was a good run with upper null plasmas throughout the day and
with Active MHD in piggy-back mode and ICRF up to 4 MW where they also found mode
conversion. Thomson scattering tests were done as well as tests of the DNB and the
fast scanning probe.

1 0.000 0.006 2 1.951 0.798
3 1.836 0.798 4 0.385 0.661
5 1.905 0.796 6 1.840 0.795
No Ip 7
8 0.000 0.002
9 1.954 0.789 10 1.689 0.792
11 1.677 0.788 12 1.691 0.791
13 1.451 0.793 14 1.560 0.797
15 1.437 0.806 16 1.506 0.796
17 1.674 0.795 18 1.839 0.796
19 0.914 0.830 20 0.000 0.039
21 1.734 0.797 22 1.844 0.794
23 0.735 0.789 24 1.209 0.796
25 1.901 0.776
Finished summary for 1030430 Total of 25 shots.
25 shots. 21 plasmas. 1 fizzles. 3 tests.


Shot 1: EF1 test shot.
Shot 2: Copied shot 1030429024 and increased the prefill by 2 ms to 27 ms duration.
Added a slow ramp in the density to nl04 = 1.23 x 10^20 m^-2. Good shot
ramped down well. Some hard x rays early.
Shot 3: Did not get the requested density ramp. Reload and try again. Good shot. Start up is better
though there are still some hard x rays. Ramp down was a bit worse but still not bad.
Shot 4: Current decays at 0.2 s leading to a disruption at 0.3 s.
Shot 5: Reduced prefill to 24 ms duration expecting excess gas after the disruption.
Good shot though the startup was worse, the rampdown was good.
Shot 6: Raised prefill to 27 ms duration again. Good shot. Low hard x rays.
Good current rise. Disrupted in rampdown.
Shot 7: Data system problem.
Shot 8: Cycle test.
Shot 9: Repeat with DNB firing at 1 s and fast scanning probe inserting three times at
0.7, 0.95, and 1.1 s. Good shot.
Shot 10: I realized that the density was not ramping as requested and Wolfe pointed
out that we are using Segment 3 rather than Segment 2, which is where I had
programmed the density ramp. So, I've now changed Segment 3 to have a density
ramp as well. Good shot.
Shot 11: Repeat. Good shot.
Shot 12: Repeat. Good shot.
Shot 13: Repeat. Good shot but the hard x rays early in the shot have returned and the
plasma disrupted at 1.45 s. Maybe the RF is overheating the upper gusset?!
Shot 14: Reduced RXU by 2 cm to -0.02 throughout the shot to attempt to avoid the
strike point heating the upper gusset. Slightly better shot. The current rise
went fine with little hard x rays. Still, the plasma disrupted at 1.55 s.
Shot 15: Reduced RXU by another 2 cm to -0.04 throughout the shot to attempt to avoid the
disruption early in the rampdown. Disrupted at 1.45 s.
Shot 16: Reduced RXU to -0.027. Still disrupted at 1.5 s. There appears to be a MARFE
starting at about 0.4 s even though the density is not very high.
Shot 17: Reduced RXU to -0.01. Also reduced the density from 0.4 s to 1.2 s to see if
I can get rid of the MARFE. The sawteeth go away early, so maybe the density
is too low at that time. Otherwise, it is a good shot though it still disrupts
at 1.65 s.
Shot 18: Increased the density early and lowered it late to give a more constant density
throughout the shot. Good shot.
Shot 19: Increased the density a little bit. Disrupted at 0.91 s. Oscillations
in EF1L from 0.6 to 0.8 s indicate there is a problem with EF1L.
Shot 20: Increased the density a little bit more. Fizzle!
Shot 21: Repeat. Good shot.
Shot 22: Repeat. Good shot.
Shot 23: EF1L went berserk at 0.6 s and led to the disruption.
Shot 24: EF1L went berserk at 1 s and led to the disruption at 1.2 s.
Shot 25: Repeat shot 24 after some work was done on EF1L. Hard x rays early and a MARFE
later, but otherwise a good shot.



Session Leader Comments

Physics Operator Comments
Apr 30 2003 08:35:40:433AMJoseph SnipesRun Plan for Tuesday, April 29, 2003
Physop: Snipes


Purpose: Clean-up, RF conditioning, diagnostic checkout

Engineering setup
_________________

ECDC in D2 overnight prior to run. 60C bake

Run starts at 9:00AM

Power systems as on 1030429024

Gas setup:
fill B-top with 6 psi of D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi of Ar Hybrid enabled (PG1)
fill B-side upper with 10 psi of D2 Hybrid DISABLED (PG2)
fill C-side with 30 psi of D2 Hybrid enabled (PG3)
ICRF: Transmitters 1 and 2 should be in Run On by 7:00 am.

Enable the ECE and DNB gate-valves, assuming no vacuum problems.
Apr 30 2003 09:01:55:473AM1030430001Joseph SnipesShot 1: EF1 test shot.
Apr 30 2003 12:23:04:033PM1030430001Joseph SnipesShot 10: I realized that the density was not ramping as requested and Wolfe pointed
out that we are using Segment 3 rather than Segment 2, which is where I had
programmed the density ramp. So, I've now changed Segment 3 to have a density
ramp as well. Good shot.
Apr 30 2003 09:30:03:643AM1030430002Joseph SnipesShot 2: Copied shot 1030429024 and increased the prefill by 2 ms to 27 ms duration.
Added a slow ramp in the density to nl04 = 1.23 x 10^20 m^-2. Good
shot ramped down well. Some hard x rays early.
Apr 30 2003 09:57:26:657AM1030430003Joseph SnipesShot 3: Did not get the requested density ramp. Reload and try again. Good shot. Start up is better
though there are still some hard x rays. Ramp down was a bit worse but still not bad.
Apr 30 2003 10:09:07:017AM1030430004Joseph SnipesShot 4: Current decays at 0.2 s leading to a disruption at 0.3 s.
Apr 30 2003 10:29:41:207AM1030430005Joseph SnipesShot 5: Reduced prefill to 24 ms duration expecting excess gas after the disruption.
Good shot though the startup was worse, the rampdown was good.
Apr 30 2003 10:45:15:463AM1030430006Joseph SnipesShot 6: Raised prefill to 27 ms duration again. Good shot. Low hard x rays.
Good current rise. Disrupted in rampdown.
Apr 30 2003 11:43:53:100AM1030430007Joseph SnipesShot 7: Data system problem.
Apr 30 2003 11:44:05:290AM1030430008Joseph SnipesShot 8: Cycle test.
Apr 30 2003 11:42:49:053AM1030430009Joseph SnipesShot 9: Repeat with DNB firing at 1 s and fast scanning probe inserting three times at
0.7, 0.95, and 1.1 s. Good shot.
Apr 30 2003 12:23:30:410PM1030430011Joseph SnipesShot 11: Repeat. Good shot.
Apr 30 2003 12:32:56:143PM1030430012Joseph SnipesShot 12: Repeat. Good shot.
Apr 30 2003 12:41:53:893PM1030430013Joseph SnipesShot 13: Repeat. Good shot but the hard x rays early in the shot have returned and the
plasma disrupted at 1.45 s. Maybe the RF is overheating the upper gusset?!
Apr 30 2003 12:59:05:497PM1030430014Joseph SnipesShot 14: Reduced RXU by 2 cm to -0.02 throughout the shot to attempt to avoid the
strike point heating the upper gusset. Slightly better shot. The current rise
went fine with little hard x rays. Still, the plasma disrupted at 1.55 s.
Apr 30 2003 01:16:04:273PM1030430016Joseph SnipesShot 15: Reduced RXU by another 2 cm to -0.04 throughout the shot to attempt to avoid the
disruption early in the rampdown. Disrupted at 1.45 s.
Apr 30 2003 01:21:32:330PM1030430016Joseph SnipesShot 16: Reduced RXU to -0.027. Still disrupted at 1.5 s. There appears to be a MARFE
starting at about 0.4 s even though the density is not very high.
Apr 30 2003 01:45:35:803PM1030430017Joseph SnipesShot 17: Reduced RXU to -0.01. Also reduced the density from 0.4 s to 1.2 s to see if
I can get rid of the MARFE. The sawteeth go away early, so maybe the density
is too low at that time. Otherwise, it is a good shot though it still disrupts
at 1.65 s.
Apr 30 2003 02:16:04:600PM1030430018Joseph SnipesShot 18: Increased the density early and lowered it late to give a more constant density
throughout the shot. Good shot.
Apr 30 2003 03:59:08:867PM1030430019Joseph SnipesShot 19: Increased the density a little bit. Disrupted at 0.91 s. Oscillations
in EF1L from 0.6 to 0.8 s indicate there is a problem with EF1L.
Apr 30 2003 02:22:33:830PM1030430020Joseph SnipesShot 20: Increased the density a little bit more. Fizzle!
Apr 30 2003 02:45:12:880PM1030430021Joseph SnipesShot 21: Repeat. Good shot.
Apr 30 2003 02:53:43:767PM1030430022Joseph SnipesShot 22: Repeat. Good shot.
Apr 30 2003 04:00:05:963PM1030430023Joseph SnipesShot 23: EF1L went berserk at 0.6 s and led to the disruption.
Apr 30 2003 04:01:44:293PM1030430024Joseph SnipesShot 24: EF1L went berserk at 1 s and led to the disruption at 1.2 s.
Apr 30 2003 05:12:16:810PM1030430025Joseph SnipesShot 25: Repeat shot 24 after some work was done on EF1L. Hard x rays early and a MARFE
later, but otherwise a good shot.
Apr 30 2003 05:21:10:260PM1030430025Joseph SnipesSummary: Overall, it was a good run with upper null plasmas throughout the day
and with Active MHD in piggy-back mode and ICRF up to 4 MW where they also found mode
conversion. Thomson scattering tests were done as well as tests of the DNB and
the fast scanning probe.


1 0.000 0.006 2 1.951 0.798
3 1.836 0.798 4 0.385 0.661
5 1.905 0.796 6 1.840 0.795
No Ip 7
8 0.000 0.002
9 1.954 0.789 10 1.689 0.792
11 1.677 0.788 12 1.691 0.791
13 1.451 0.793 14 1.560 0.797
15 1.437 0.806 16 1.506 0.796
17 1.674 0.795 18 1.839 0.796
19 0.914 0.830 20 0.000 0.039
21 1.734 0.797 22 1.844 0.794
23 0.735 0.789 24 1.209 0.796
25 1.901 0.776
Finished summary for 1030430 Total of 25 shots.
25 shots. 21 plasmas. 1 fizzles. 3 tests.

Engineering Operator Comments
ShotTimeTypeStatusComment
109:07:22:560AMTestOkEF1 Power Supply PLC Test
209:24:34:163AMPlasmaOk
309:49:20:317AMPlasmaOk
410:01:49:990AMPlasmaOk
510:24:00:680AMPlasmaOk
610:36:32:653AMPlasmaOk
811:28:51:750AMTestOkData System Test
911:39:45:547AMPlasmaOk
1011:54:56:790AMPlasmaOk
1112:11:09:690PMPlasmaOk
1212:23:40:457PMPlasmaOk
1312:36:12:760PMPlasmaOk
1412:49:11:090PMPlasmaOk
1501:02:01:220PMPlasmaOk
1601:15:09:833PMPlasmaOk
1701:31:46:267PMPlasmaOk
1801:46:27:197PMPlasmaOk
1902:01:09:000PMPlasmaOk
2002:19:43:230PMPlasmaOk
2102:32:24:610PMPlasmaOk
2202:45:26:770PMPlasmaOk
2302:59:02:180PMPlasmaOk
2403:14:44:800PMPlasmaBadEF1 Self Powered Crowbar Fired
2505:07:14:427PMPlasmaOk