Miniproposals

Miniproposal: Date Filed: Title: First Author: Session Leader: Martin Greenwald (shots 1-48)

Engineering Operator Run Comment

first norm. field run

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Entered: Jul 7 2004 03:49:15:600PM

Author: To Be Determined

Run Summary for 960209 - Dimensionless Similarity Experiment Plan: We are trying to "match" a shot from D3D - similar to the run on 950407 but with lower radiated power. The main activity will be getting a "good" match then running a set of constant shots to complete an ion temperature profile with HIREX. The conditions we are looking for are: R = .67 a = .22 kappa = 1.67 delta u = .3 delta l = .6 Bt = 5.3 Ip = 1.05 - 1.1 (qeng = 3.8) Pinput = 4.0 MW nebar = 2.0 Results: A difficult day. The morning hours were spent testing and debugging after the field reversal. Most of the afternoon was spent learning how to get break down with reversed field; the first shot with an Ip flat-top was at 16:45. Afterwards we were plagued with a cycle of disruptions and fizzles. Still a few good shots were obtained and may be suitable for comparison with the D3D data. Instant analysis: Shot 42 had 100 kJ, comparable to the scaled D3D shots but with only 3MW compared to (scaled) 4 MW for D3D. Radiation was much lower than on 950407; 0.85 MW now vs 3.5 MW then. D3D had (scaled) .9 MW. The suggestion is that B*Tau is better on C-Mod by 25% ; Detailed profile analysis must now be performed. Details for "good" shots: 960229031 >>> Fiducial Shot - lasts 1.5 sec 960229032 >>> Good shot, Prf = 1.2 MW; not high enough 960229034 >>> Good heating, Prf = 3MW betat = .8; a bit too high. nebar = 2.2 also high qeng = 3.9 also high 960229036 >>> Better match nebar = 2 qeng = 3.8 Prf to 2.6, betat =.8 still too high Wmhd = 130 kJ too high 960229037 >>> Disrupts at .7 Prf to 2.2, betat =.65 Wmhd = 100 kJ 960229039 >>> Disrupts at .75 Prf to 2.2, betat = .68 Wmhd = 105 kJ 960229042 >>> Best shot of the day; use t = .65-.75 Prf = 2.2, Poh = 1.0; Pabs ~ 3MW betat = .7 Wmhd = 100 nebar= 2 qeng = 3.8 960229044 >>> Similar conditions; Disrupts at .73 Prf = 2.2 betat = .7 Wmhd = 105 kJ 960229045 >>> Disrupts at .69 Prf = 2.2 betat = .7 Wmhd = 100 kJ

Physics Operator Summaries

Entered: Jul 7 2004 04:36:56:317PM

Author: To Be Determined

960229 MP 85A Dimensionless Similarity Session Leader: Martin Greenwald Physics Operator: Joseph Snipes Engineer in Charge: Vince Bertolino Standard ECDC in D for two hours before the run. Enable A-side (K-side) valve with 20 psi of D and B-top with 5 psi of D. B-side lower filled with 4 psi of Ar but not enabled for the fiducial. Plan is to run plasmas with dimensionless similarity to DIII-D with the same plasma shape. We will setup with a fiducial shot from 960227003 but with abnormal toroidal field direction. Then, we will setup with shot 960214026, but with abnormal toroidal field direction. The parameters are Ip=1 MA, Bt=5.3 T, we will run at nebar = 2 x 10^20 m^-3 with as much ICRF power as available. First 12 shots have been power supply tests after reversing both TF and Ip polarities. When we finally started the program, there was difficulty getting the RCUR offsets and Br offsets correct, but by shot 31, we got a good fiducial shot. Then we managed to get a number of decent shots, but we were perpetually plagued by disruptions. Many occurred right as the current was programmed to turn over, but others occured during the middle of the RF pulse and they seemed to move with the RF when we moved the RF timing, which suggests that the RF was heating some Moly tiles and leading to increased sputtering of the moly. One suggestion was that the strike point was at the junction between the divertor floor and the vertical plate on the inboard side, but when we tried to move the equilibrium a bit, it did not help. One of the main points of the run was to keep a specific plasma shape to match DIII-D, so we did not want to change the equilibrium very much. Still, with luck, the Ti profiles from HIREX will be reasonable. Shot 13: Start with fiducial setup by Wolfe yesterday, which is a copy of shot 960227003 modified for reversed TF and Ip. Reduced pre-puff to 12 msec flattop and set RCUR offsets to 1000 in both segment 1 and 2. Br offset set at 5.5 mT. Dud! Too much Br and Bz. Shot 14: Added 2 msec to the pre-puff to 14 msec flattop. Changed Br offset to 4 mT, Decreased OH1 current by 700 A from 16600 to 15900 A and increased EF4 current by 80 A from 1180 to 1260 A. Fizzle! Late breakdown at 45 msec. Shot 15: Added 90 A to EF4 to 1350 A. Added 0.5 mT to Br offset to 4.5 mT. Dud! Shot 16: Br offset set to 0 despite the fact that the Br signal looks close to zero already because the flux plot still shows radial field problems. Fizzle! Late breakdown at 17 msec. Shot 17: Set Br offset to -0.5 mT. Decreased OH2 current by 200 A to 22000 A. Decreased OH1 current by 100 A to 15800 A. Comparison with shot 950407013 showed that the Br offset there led to a Br signal of about -4.5 mT. Dud! Shot 18: Increased OH1 to 16200 A. Fizzle! Breakdown at 5.9 msec. Looks better. Shot 19: Br offset returned to 0. OH1 current set to 16100 A. Late breakdown at 17 msec. Shot 20: OH1 current returned to 16200 A. RCUR offset changed from 1000 to 4000 in both segment 1 and 2. Late breakdown at 10 msec. Shot 21: RCUR offset set to -2000 in both segment 1 and 2. OH2 commutation switch fault. Need to replace fuse in TF circuit as well. Shot 22: Repeat. Fizzle! Shot 23: RCUR offset set to -5000 in segment 1. Got current rise, but there are problems with the RCUR offset at segemnt switch. Shot 24: RCUR offset set to -5000 in segment 2. RCUR set to 0.653 m between 0.1 and 0.15 sec in segment 2 to have no jump in RCUR at the segment switch. Shot 25: Added 20 A to EF4 to reduce the vertical field. Fizzle! Shot 26: Br offset set to +0.4 mT and 2 msec added to pre-puff to 16 msec. Fizzle. Breakdown at 6.75 msec. Shot 27: Changed EF4 current to 1330 A before t = 0. Got current rise. Disrupted after segment switch. Shot 28: Changed RCUR offset to -6000 in segment 1 and -4000 in segment 2. Got current rise. Disrupted at 0.11 sec. Shot 29: Changed RCUR offset to -2000 in segment 2 to try to push the plasma further out since it is riding on the inner wall already at 0.1 sec. Changed RCUR in segment 1 to be 0.655 m and to remain so until 0.165 in segment 2. Fizzle! Shot 30: Changed RCUR in segment 1 to be 0.653 m early then ramp from 0.05 sec to 0.1 sec from 0.653 to 0.663 m at Wolfe's suggestion. Shot 31: Increased gas puff between 0.01 and 0.1 sec to slow down the current rise. Good shot. Shot 32: Increased early gas some more. Loaded segment 2 from the shot I made up combining the lower null from 960116024 and the upper null from 960214026 with properly flipped waveforms. Also set RCUR offset to -2000 in the new segment 2. Good shot. Disrupted at 1.1 sec. Shot 33: Moved CLEARIN out by 5 mm to increase the inner gap, moved RXU and ZXU in and up by 1 cm to reduce the upper triangularity. Increased the density to 1.1 x 10^20 m^-2. Fizzle! Shot 34: Repeat. Good shot. Still disrupted at 1.05 sec. Shot 35: Moved ZXU up to 0.08 cm and moved RXU in one more cm. Fizzle with fizzle detector off on the TF so that we could get a TF baseline for the diamagnetic loop. Shot 36: Try again. Good shot. Still disrupted at 1.06 sec. Locked mode at 1.05 sec. Shot 37: Extended RXL, ZXL, and RXU gains out to 1.4 sec. nl04 raised to 1.21 x 10^20 m^-2. Hit by a moly brick at 0.75 sec. Shot 38: Moved RXU back in by 1.0 cm and moved ZXU down by 1.5 cm. Fizzle! Shot 39: Repeat. Disrupted at 0.75 sec. Again there is a big moly injection. Perhaps the plasma is hitting the inner nose. Shot 40: Moved RXL out by 2 mm from -0.005 to -0.003 and moved ZXL up by 2 mm to -0.018 m. Fizzle! Shot 41: Reduced pre-puff by 3 msec to 14 msec flattop. Disrupted at 0.25 sec. May be yet another moly brick. Shot 42: Repeat. Good shot. Still disrupted at 1.06 sec. Shot 43: Repeat. Fizzle! Shot 44: Moved turn over times of ZXL, ZXU, and CLEARIN to 1.0 sec. Disrupted at 0.74 sec. Appears to be a moly brick again. Shot 45: Modified rollover of Ip to make a smooth change through q=4. Disrupted at 0.7 sec. Shot 46: Repeat. Disrupted at 0.63 sec. Shot 47: Moved RXL out and ZXL up by 0.5 cm. Disrupted at 0.6 sec. Shot 48: Try again. One last time.

Session Leader Comments
Feb 29 1996 08:32:29:370AM		Martin Greenwald	We are trying to "match" a shot from D3D - similar to the run on 950407 but with lower radiated power. The conditions we are looking for are: R = .67 a = .22 kappa = 1.67 delta u = .3 delta l = .6 Bt = 5.3 Ip = 1.05 - 1.1 (qeng = 3.8) Pinput = 4.0 MW nebar = 2.0 The main activity will be getting a "good" match then running a set of constant shots to complete an ion temperature profile with HIREX. If we finish this early, we will run a few shots to finish the rhostar scans (122A)
Feb 29 1996 11:09:47:230AM	960229013	Martin Greenwald	First attempt (previous were all tests) Fizzles
Feb 29 1996 11:38:52:820AM	960229014	Martin Greenwald	Fizzle
Feb 29 1996 02:57:32:370PM	960229023	Martin Greenwald	First real plasma, only .22 seconds long though
Feb 29 1996 02:57:51:270PM	960229024	Martin Greenwald	Fizzle
Feb 29 1996 02:57:58:710PM	960229025	Martin Greenwald	Fizzle
Feb 29 1996 03:22:59:740PM	960229027	Martin Greenwald	Reached .12 seconds, .45 MA
Feb 29 1996 03:35:18:900PM	960229028	Martin Greenwald	Reached .12 seconds, .45 MA
Feb 29 1996 04:45:46:750PM	960229031	Martin Greenwald	Fiducial Shot - lasts 1.5 sec
Feb 29 1996 06:12:12:970PM	960229032	Martin Greenwald	Good shot, Prf not high enough
Feb 29 1996 06:12:54:930PM	960229033	Martin Greenwald	Fizzle
Feb 29 1996 06:11:03:360PM	960229034	Martin Greenwald	Good heating, Prf = 3MW betat a bit too high.
Feb 29 1996 06:11:28:330PM	960229035	Martin Greenwald	Fizzle
Feb 29 1996 06:51:51:210PM	960229036	Martin Greenwald	Disrupts at 1. Prf to 2.6, betat =.6=8 Wmhd = 130 kJ too high
Feb 29 1996 06:49:57:210PM	960229037	Martin Greenwald	Disrupts at .8 Prf to 2.2, betat =.65 Wmhd = 100 kJ
Feb 29 1996 07:10:01:640PM	960229039	Martin Greenwald	Disrupts at .75 Prf to 2.2, betat = .68 Wmhd = 105 kJ
Feb 29 1996 07:29:22:610PM	960229041	Martin Greenwald	Disrupts early
Feb 29 1996 07:44:11:520PM	960229042	Martin Greenwald	Lasts til end of flat top Prf = 2.2 betat = .7 Wmhd = 100
Feb 29 1996 08:22:30:040PM	960229044	Martin Greenwald	Disrupts at .7 Prf = 2.2 betat = .7 Wmhd = 105 kJ
Feb 29 1996 08:35:00:820PM	960229045	Martin Greenwald	Disrupts at .7 Prf = 2.2 betat = .7 Wmhd = 100 kJ
Feb 29 1996 09:04:40:890PM	960229046	Martin Greenwald	disruption at .6
Feb 29 1996 09:04:50:620PM	960229047	Martin Greenwald	disruption at .6
Feb 29 1996 09:01:48:670PM	960229048	Martin Greenwald	fizzle

Physics Operator Comments
Feb 29 1996 08:29:14:480AM		Joseph Snipes	MP 85A Dimensionless Similarity Session Leader: Martin Greenwald Physics Operator: Joseph Snipes Engineer in Charge: Vince Bertolino Standard ECDC in D for two hours before the run. Enable A-side (K-side) valve with 20 psi of D and B-top with 5 psi of D. B-side lower filled with 4 psi of Ar but not enabled for the fiducial. Plan is to run plasmas with dimensionless similarity to DIII-D with the same plasma shape. We will setup with a fiducial shot from 960227003 but with abnormal toroidal field direction. Then, we will setup with shot 960214026, but with abnormal toroidal field direction. The parameters are Ip=1 MA, Bt=5.3 T, we will run at nebar = 2 x 10^20 m^-3 with as much ICRF power as available.
Feb 29 1996 11:24:37:520AM	960229013	Joseph Snipes	First shots have been power supply tests after reversing both TF and Ip polarities. Shot 13: Start with fiducial setup by Wolfe yesterday, which is a copy of shot 960227003 modified for reversed TF and Ip. Reduced pre-puff to 12 msec flattop and set RCUR offsets to 1000 in both segment 1 and 2. Br offset set at 5.5 mT. Dud! Too much Br and Bz.
Feb 29 1996 11:37:59:630AM	960229014	Joseph Snipes	Shot 14: Added 2 msec to the pre-puff to 14 msec flattop. Changed Br offset to 4 mT, Decreased OH1 current by 700 A from 16600 to 15900 A and increased EF4 current by 80 A from 1180 to 1260 A. Fizzle!
Feb 29 1996 12:54:04:020PM	960229015	Joseph Snipes	Shot 15: Added 90 A to EF4 to 1350 A. Added 0.5 mT to Br offset to 4.5 mT. Dud!
Feb 29 1996 12:54:20:360PM	960229016	Joseph Snipes	Shot 16: Br offset set to 0 despite the fact that the Br signal looks close to zero already because the flux plot still shows radial field problems. Fizzle! Late breakdown at 17 msec.
Feb 29 1996 12:54:36:220PM	960229017	Joseph Snipes	Shot 17: Set Br offset to -0.5 mT. Decreased OH2 current by 200 A to 22000 A. Decreased OH1 current by 100 A to 15800 A. Comparison with shot 950407013 showed that the Br offset there led to a Br signal of about -4.5 mT. Dud!
Feb 29 1996 12:58:51:670PM	960229018	Joseph Snipes	Shot 18: Increased OH1 to 16200 A. Fizzle! Breakdown at 5.9 msec. Looks better.
Feb 29 1996 01:38:21:370PM	960229019	Joseph Snipes	Shot 19: Br offset returned to 0. OH1 current set to 16100 A. Late breakdown at 17 msec.
Feb 29 1996 01:39:01:990PM	960229020	Joseph Snipes	Shot 20: OH1 current returned to 16200 A. RCUR offset changed from 1000 to 4000 in both segment 1 and 2. Late breakdown at 10 msec.
Feb 29 1996 01:48:51:280PM	960229021	Joseph Snipes	Shot 21: RCUR offset set to -2000 in both segment 1 and 2. OH2 commutation switch fault.
Feb 29 1996 02:45:57:770PM	960229021	Joseph Snipes	Shot 21: RCUR offset set to -2000 in both segment 1 and 2. OH2 commutation switch fault. Need to replace fuse in TF circuit as well.
Feb 29 1996 02:46:17:400PM	960229022	Joseph Snipes	Shot 22: Repeat. Fizzle!
Feb 29 1996 02:46:39:900PM	960229023	Joseph Snipes	Shot 23: RCUR offset set to -5000 in segment 1. Got current rise, but there are problems with the RCUR offset at segemnt switch.
Feb 29 1996 02:58:05:710PM	960229024	Joseph Snipes	Shot 24: RCUR offset set to -5000 in segment 2. RCUR set to 0.653 m between 0.1 and 0.15 sec in segment 2 to have no jump in RCUR at the segment switch.
Feb 29 1996 03:05:20:680PM	960229025	Joseph Snipes	Shot 25: Added 20 A to EF4 to reduce the vertical field. Fizzle!
Feb 29 1996 03:19:16:360PM	960229026	Joseph Snipes	Shot 26: Br offset set to +0.4 mT and 2 msec added to pre-puff to 16 msec. Fizzle. Breakdown at 6.75 msec.
Feb 29 1996 03:28:54:190PM	960229027	Joseph Snipes	Shot 27: Changed EF4 current to 1330 A before t = 0. Got current rise. Disrupted after segment switch.
Feb 29 1996 03:49:44:340PM	960229028	Joseph Snipes	Shot 28: Changed RCUR offset to -6000 in segment 1 and -4000 in segment 2. Got current rise. Disrupted at 0.11 sec.
Feb 29 1996 03:50:24:860PM	960229029	Joseph Snipes	Shot 29: Changed RCUR offset to -2000 in segment 2 to try to push the plasma further out since it is riding on the inner wall already at 0.1 sec. Changed RCUR in segment 1 to be 0.655 m and to remain so until 0.165 in segment 2. Fizzle!
Feb 29 1996 05:05:32:220PM	960229030	Joseph Snipes	Shot 30: Changed RCUR in segment 1 to be 0.653 m early then ramp from 0.05 sec to 0.1 sec from 0.653 to 0.663 m at Wolfe's suggestion.
Feb 29 1996 05:06:00:910PM	960229031	Joseph Snipes	Shot 31: Increased gas puff between 0.01 and 0.1 sec to slow down the current rise. Good shot. Fiducial. No RF to speak of.
Feb 29 1996 05:33:09:860PM	960229032	Joseph Snipes	Shot 32: Increased early gas some more. Loaded segment 2 from the shot I made up combining the lower null from 960116024 and the upper null from 960214026 with properly flipped waveforms. Also set RCUR offset to -2000 in the new segment 2. Good shot. Disrupted at 1.1 sec.
Feb 29 1996 06:07:39:490PM	960229033	Joseph Snipes	Shot 33: Moved CLEARIN out by 5 mm to increase the inner gap, moved RXU and ZXU in and up by 1 cm to reduce the upper triangularity. Increased the density to 1.1 x 10^20 m^-2. Fizzle!
Feb 29 1996 06:07:58:220PM	960229034	Joseph Snipes	Shot 34: Repeat. Good shot. Still disrupted at 1.05 sec.
Feb 29 1996 06:13:34:840PM	960229035	Joseph Snipes	Shot 35: Moved ZXU up to 0.08 cm and moved RXU in one more cm. Fizzle with fizzle detector off on the TF so that we could get a TF baseline for the diamagnetic loop.
Feb 29 1996 06:35:01:220PM	960229036	Joseph Snipes	Shot 36: Try again. Good shot. Still disrupted at 1.06 sec. Locked mode at 1.05 sec.
Feb 29 1996 06:50:01:500PM	960229037	Joseph Snipes	Shot 37: Extended RXL, ZXL, and RXU gains out to 1.4 sec. nl04 raised to 1.21 x 10^20 m^-2. Hit by a moly brick at 0.75 sec.
Feb 29 1996 07:00:39:810PM	960229038	Joseph Snipes	Shot 38: Moved RXU back in by 1.0 cm and moved ZXU down by 1.5 cm. Fizzle!
Feb 29 1996 07:35:31:700PM	960229039	Joseph Snipes	Shot 39: Repeat. Disrupted at 0.75 sec. Again there is a big moly injection. Perhaps the plasma is hitting the inner nose.
Feb 29 1996 07:36:07:550PM	960229040	Joseph Snipes	Shot 40: Moved RXL out by 2 mm from -0.005 to -0.003 and moved ZXL up by 2 mm to -0.018 m. Fizzle!
Feb 29 1996 07:36:23:750PM	960229041	Joseph Snipes	Shot 41: Reduced pre-puff by 3 msec to 14 msec flattop. Disrupted at 0.25 sec. May be yet another moly brick.
Feb 29 1996 07:43:42:940PM	960229042	Joseph Snipes	Shot 42: Repeat. Good shot. Still disrupted at 1.06 sec.
Feb 29 1996 08:00:16:190PM	960229043	Joseph Snipes	Shot 43: Repeat. Fizzle!
Feb 29 1996 08:14:43:770PM	960229044	Joseph Snipes	Shot 44: Moved turn over times of ZXL, ZXU, and CLEARIN to 1.0 sec. Disrupted at 0.74 sec. Appears to be a moly brick again.
Feb 29 1996 08:37:41:220PM	960229045	Joseph Snipes	Shot 45: Modified rollover of Ip to make a smooth change through q=4. Disrupted at 0.7 sec.
Feb 29 1996 09:10:15:070PM	960229047	Joseph Snipes	Shot 47: Moved RXL out and ZXL up by 0.5 cm. Disrupted at 0.6 sec.
Feb 29 1996 09:10:42:600PM	960229048	Joseph Snipes	Shot 48: Try again. One last time. Fizzle!

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	08:09:47:610AM	Test	Ok	ef2l test ok
2	08:17:39:570AM	Test	Ok
3	08:24:27:850AM	Test	Ok
4	09:10:56:830AM	Test	Bad	operator error
5	09:18:15:100AM	Test	Ok
6	09:24:45:280AM	Test	Ok
7	09:32:23:610AM	Test	Ok
8	09:44:13:180AM	Test	Ok
9	09:51:49:550AM	Test	Ok
10	09:58:34:000AM	Test	Ok
11	10:05:49:660AM	Test	Ok
12	10:13:31:640AM	Test	Ok
13	10:59:57:900AM	Plasma	Ok
14	11:24:38:990AM	Plasma	Ok
15	11:43:38:540AM	Plasma	Ok
16	12:04:03:400PM	Plasma	Ok
17	12:40:03:290PM	Plasma	Ok
18	12:54:05:040PM	Plasma	Ok
19	01:14:12:600PM	Plasma	Ok
20	01:27:12:180PM	Plasma	Ok
21	01:41:24:080PM	Plasma	Ok	OH2U Comm. fault converter and bypass TF IOC cabinets 5&6 Also bypasss
22	02:19:27:240PM	Plasma	Ok	No Faults
23	02:29:23:350PM	Plasma	Ok
24	02:45:43:270PM	Plasma	Ok
25	02:55:50:300PM	Plasma	Ok
26	03:06:10:090PM	Plasma	Ok
27	03:18:24:270PM	Plasma	Ok	OH2U IOC & bypass comm. fault OH1 self powered fired
28	03:31:20:220PM	Plasma	Ok	OH2u comm fail bypass , OH1 Self powered fired
29	03:48:42:490PM	Plasma	Ok	no faults.
30	04:11:50:370PM	Plasma	Ok	Comm. fault Bypass OH2u
31	04:32:56:800PM	Plasma	Ok
32	05:03:07:970PM	Plasma	Ok
33	05:31:38:160PM	Plasma	Ok
34	05:41:56:650PM	Plasma	Ok
35	06:08:18:450PM	Plasma	Ok
36	06:17:17:900PM	Plasma	Ok
37	06:35:59:380PM	Plasma	Ok
38	06:49:46:580PM	Plasma	Ok
39	07:00:14:530PM	Plasma	Ok
40	07:13:33:750PM	Plasma	Ok
41	07:22:12:070PM	Plasma	Ok
42	07:35:18:040PM	Plasma	Ok
43	07:53:50:030PM	Plasma	Ok
44	08:03:10:290PM	Plasma	Ok
45	08:24:56:640PM	Plasma	Ok
46	08:36:26:010PM	Plasma	Ok
47	08:47:50:490PM	Plasma	Ok
48	08:59:31:030PM	Plasma	Ok