Miniproposals

Miniproposal: 237 Date Filed: 3/10/1999 Title: Scaling of Toroidal Rotation with Plasma Current First Author: John Rice Session Leader: John Rice (shots 1-25)

Engineering Operator Run Comment

MP# 237/Irby,Silva

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Entered: Jul 7 2004 03:49:21:443PM

Author: To Be Determined

Run summary for 990920, MP237, Toroidal Rotation during Plasma Current Scan The purpose of this run was to determine the scaling of the rotation velocity with plasma current, for otherwise constant target plasmas, for H-mode discharges. The range of currents achieved was from 1.36 down to .42 MA, at nearly constant target electron density, and at 2 MW ICRF power. Good toroidal rotation measurements were made on a majority of the shots, and there is a very clear trend of rotation velocity normalized to the plasma stored energy decreasing with increasing plasma current. There were some CaF2 injections as well, with some shell formation seen on the top x-ray array, with very good time resolution. Some of the discharges had all four ICRF transmitters operational, with a total of 4.6 MW achieved on shot 19.

Physics Operator Summaries

Entered: Jul 7 2004 04:37:09:317PM

Author: To Be Determined

Continuation of MP#237: Ip Scaling of Rotation Session Leader: J. Rice EOs: Silva, Cochran, Dekow PO: Irby Setup Power Supplies from Shot 990916003 Two Hours of ECDC in D2 prior to run. Gas setup: Fill B-Top with 6 psi D2, Hybrid Enabled Fill B-side lower with 1 psi Ar, Hybrid Enabled Fill B-side upper with 6 psi H2, Hybrid DISABLED Fill C-Side with 30 psi D2, Hybrid Enabled J-Bottom as is, Hybrid DISABLED ECE and VUV valves enabled, if no vacuum problems After "Tuesday" test run will begin with a repeat of shot 990916003 We will scan Ip down to lowest reasonable levels and then scan it upwards to get as wide range of Ip scaling of rotation as possible. Results: This run was a very good one in which I believe most if not all the physics goals were accomplished. The machine ran extremely well with no fizzles and four disruptions. Two disruptions were during our attempts to run at very low current (400 kA), and two were at the highest current operation at 1.4 MA. Halo currents somewhat higher than 200 kA were seen in the downward going high current disruptions. Record ICRF power was coupled to the plasma today (shot 17 for example: 4.3 MW, 170 kJ). The last shot (25) at high current got up to 187 kJ. Problems: b-side-upper still has a problem. Hybrid is generating pulse but nothing getting out of final amp. OH2L again produced twice the asked for current under PLC control. Supply was checked and reset. Next try was okay. TCI CO2 laser power is very low. Only 3 channels operational and feedback was lost on one shot. 400 kA shots hard to run at requested density. Tried clearin, rcur tweaks again. Score: 25 shots 2 tests 2 low current disruptions (both at abt 0.47 s) 2 full current disruptions (1.2 MA at about 1.5 seconds) 23 plasmas 0 fizzles, 0 duds

Session Leader Comments
Sep 20 1999 10:44:26:670AM	990920003	John Rice	0.8 MA, only 1 MW RF
Sep 20 1999 10:48:05:733AM	990920004	John Rice	0.8 MA, only 1 MW RF
Sep 20 1999 11:05:19:123AM	990920005	John Rice	0.8 MA, no RF, no density feedback
Sep 20 1999 11:49:40:420AM	990920006	John Rice	0.8 MA, 2 MW RF, good shot for rotation
Sep 20 1999 12:05:14:373PM	990920006	John Rice	0.8 MA, 2 MW RF, another good shot for rotation
Sep 20 1999 12:05:20:500PM	990920007	John Rice	0.8 MA, 2 MW RF, another good shot for rotation
Sep 20 1999 12:25:56:873PM	990920008	John Rice	0.6 MA, 2 MW RF, good shot for rotation
Sep 20 1999 12:48:12:797PM	990920009	John Rice	0.6 MA, 2 MW RF, another good shot for rotation
Sep 20 1999 01:02:14:747PM	990920010	John Rice	0.4 MA, disrupted
Sep 20 1999 01:24:59:730PM	990920011	John Rice	0.4 MA, 1.8 MW RF, good rotation data
Sep 20 1999 01:38:37:013PM	990920012	John Rice	0.4 MA, disrupted
Sep 20 1999 01:59:51:230PM	990920013	John Rice	0.4 MA, 2 MW RF, big Mo injection at .98s
Sep 20 1999 02:16:59:467PM	990920014	John Rice	0.4 MA, 2 MW RF, good rotation
Sep 20 1999 02:38:45:590PM	990920015	John Rice	0.8 MA, 2 MW RF, good rotation, earlier RF pulse
Sep 20 1999 03:11:30:293PM	990920016	John Rice	1.0 MA, 2 MW RF, ELM-free
Sep 20 1999 03:33:18:530PM	990920018	John Rice	1.0 MA, 1 MW RF
Sep 20 1999 04:03:04:513PM	990920019	John Rice	1.0 MA, 2 MW RF
Sep 20 1999 04:14:47:247PM	990920020	John Rice	1.2 MA, RF trip
Sep 20 1999 04:33:37:090PM	990920021	John Rice	1.2 MA, RF trip
Sep 20 1999 05:02:42:513PM	990920022	John Rice	1.2 MA, 1.9 MW RF, good rotation
Sep 20 1999 05:22:08:543PM	990920023	John Rice	1.2 MA, 1.9 MW RF, good rotation
Sep 20 1999 05:38:57:967PM	990920024	John Rice	1.4 MA, 2.0 MW RF, good rotation
Sep 20 1999 05:58:12:420PM	990920025	John Rice	1.4 MA, 2.0 MW RF, good rotation

Physics Operator Comments
Sep 20 1999 07:16:34:967AM		Jim Irby	Did coldstart. No problems
Sep 20 1999 07:52:34:343AM		Jim Irby	Loaded 990916001 -- load/clean
Sep 20 1999 08:10:42:843AM		Jim Irby	At John's request I loaded 990916003 Better shot for the 800 kA case.
Sep 20 1999 08:35:12:950AM		Jim Irby	Tommy has gone into the cell to exercise b-side-upper. We have pumped out all the H2 and replaced it with 2 psi D2.
Sep 20 1999 09:00:16:107AM		Jim Irby	Tommy was able to bring the pressure up to the 1e-6 Torr range with the DC supply on b-side-upper. We will enable this valve during the OH test (with D2) to see if it's working or not.
Sep 20 1999 09:44:28:653AM		Jim Irby	b-side-upper gas from 0.60 to 0.61 seconds at 100% open SW tells me that fmit#1 is still "ticking down" though much less frequently than last Thursday. However, the tick downs are resulting in crowbars. We may have done damage to blocking caps last week.
Sep 20 1999 09:50:25:983AM	990920001	Jim Irby	Basepressure 1.7e-7 Torr before shot Got gas from b-side-upper Got twice the requested current on OH2L. Same problem as seen a couple of weeks ago. Will probably cycle power on supply.
Sep 20 1999 10:05:34:560AM	990920001	Jim Irby	Correction: Nija was enabled. No sign of gas from b-side-upper
Sep 20 1999 10:16:04:013AM	990920002	Jim Irby	b-side-upper gas now from 0.60 0.65 seconds Nija has been disabled No sign of gas from b-side-upper. John Goetz is checking signals. OH2L now looks fine.
Sep 20 1999 10:43:41:060AM	990920003	Jim Irby	Good shot Nija was enabled again with helium puff 1 MW out of #1, #3 and #4 are also coming online at about 500 kW each. TCI is having troubles. John tells me j-port is producing lots of moly
Sep 20 1999 11:00:05:967AM	990920004	Jim Irby	Repeat with #2 running I hope. 1 MW out of #2, but no #1.
Sep 20 1999 11:08:53:920AM	990920005	Jim Irby	Plasma TCI lost track and did in feedback. Lost plasma at 1.135
Sep 20 1999 11:52:21:857AM	990920006	Jim Irby	Good shot: 2 MW of RF Gap okay for RF Rick and I made alignment changes to TCI CO2 laser. Power still low, but large enough to keep feedback working. Br0 is rather high at +.00025 T at 5 ms Bz0 is about +.003 T at 5 ms
Sep 20 1999 12:03:25:763PM	990920007	Jim Irby	No tweaks Good shot: 2 MW RF
Sep 20 1999 12:25:18:700PM	990920008	Jim Irby	Dropped current to 600 kA by 0.55 seconds Good shot: RF okay Lost plasma at 1.65 seconds, .49 MA
Sep 20 1999 12:42:43:450PM	990920009	Jim Irby	Repeat : no tweaks. Br0 and Bz0 looked okay last shot basepressure 1.8e-6 Torr before shot Good shot: 2 MW RF Lost plasma at 1.67 seconds
Sep 20 1999 01:16:02:280PM	990920010	Jim Irby	Plasma current to 400 kA. Loaded shot 990916012 from last thursday. Lost plasma at 0.448 seconds gaps too big again even though this should have been fixed for this shot
Sep 20 1999 01:26:51:280PM	990920011	Jim Irby	Adjusted gaps: clearin from -.021 to -.023 early in shot at 0.365 seconds rcur from 0.676 to 0.678 Good shot: Thanks to John Goetz again.
Sep 20 1999 01:45:45:857PM	990920012	Jim Irby	Repeat RF guys have done a little tuning Lost plasma at 0.477 seconds again
Sep 20 1999 02:08:02:640PM	990920013	Jim Irby	Repeat --- nothing found to explain why shot 12 should be different from shot 11 Good Shot: 2 MW of RF
Sep 20 1999 02:18:29:687PM	990920014	Jim Irby	repeat ---- hope this is last shot at 400 kA Good shot ---- John is happy ---- RF okay
Sep 20 1999 02:38:01:733PM	990920015	Jim Irby	Reloading shot 990920007 ---- 800 kA basepressure before shot 1.2e-6 Torr Good shot Forgot to open impurity injector gatevalve! ********************************************************* Allllllllllllll transmitters ran: Almost 4 MW ---- new C-Mod record *********************************************************
Sep 20 1999 03:10:31:937PM	990920016	Jim Irby	Going to 1 MA --- loaded clean Impurity injector gatevalve enabled --- CaF at 0.9 seconds Plasma Went elm-free and caused some problems
Sep 20 1999 03:23:45:530PM	990920017	Jim Irby	Ip still 1 MA Raised density to 1.e20 from 9.e19 m^-2 on NL_04 basepressure before shot 1.7e-6 Torr Plasma: Great shot: 4.2 MW of RF Stored energy up to 169 kJ!
Sep 20 1999 03:43:16:810PM	990920018	Jim Irby	Repeat at 1 MA --- John lost high voltage on detector on the last shot Lost fmit#1 on that shot -- will have to repeat --- only 1 MW Rf
Sep 20 1999 04:03:11:623PM	990920019	Jim Irby	Repeat at 1 MA ---- need D and E Great shot
Sep 20 1999 04:21:16:187PM	990920020	Jim Irby	Ip to 1.2 MA Ef4 programming to 3400 A --- less control required? RCUR to 0.668 from 0.669 --- a little more room at high current Plasma ---- lost HeNe 2 and therefore feedback Got requested current
Sep 20 1999 04:44:46:357PM	990920021	Jim Irby	Repeat of last shot, but we hope with density feedback and RF Plasma okay --- problems with RF
Sep 20 1999 05:12:56:890PM	990920022	Jim Irby	requesting Ip at 1.2 MA RCUR to 0.667 from 0.668 m to give a little more outer gap for the antennas Density request to 1.1e20 from 1.0e20 to keep us in EDA mode Good shot: RF and density okay Ip coming up strongly at about 0.4 seconds following OH1 crossover Radiation getting high midway through rf pulse as we go elm-free
Sep 20 1999 05:25:37:340PM	990920023	Jim Irby	John very happy with last shot ---- will repeat Good shot --- RF okay
Sep 20 1999 05:50:15:453PM	990920024	Jim Irby	Ip request to 1.4 MA EF4 programming to 3600 Amps Density request up to 1.2e20 Plasma ------------- full current disruption at 1.4 MA, 1.526 seconds --- big jump on rangefinder
Sep 20 1999 06:09:38:420PM	990920025	Jim Irby	Density request to 1.3e20 RCUR to 0.666 m --- very small gaps on last shot Plasma Nearly full current disruption at 1.57 seconds halo current about 200 kA rangefinder amplitude approx 40 um 184 kJ stored energy

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	09:46:13:403AM	Test	Bad	OH1,@2u,l test bad. OH2 l current is twice the prog. ammount.
2	10:10:36:297AM	Test	Ok	OH1@2u,l test. OK
3	10:26:40:700AM	Plasma	Ok	no faults/plasma
4	10:42:57:983AM	Plasma	Ok	no faults/plasma
5	10:59:51:763AM	Plasma	Ok	no faults/disrupt
6	11:39:52:763AM	Plasma	Ok	no faults/plasma
7	11:56:46:797AM	Plasma	Ok	no faults/plasma
8	12:17:30:593PM	Plasma	Ok	(null)
9	12:37:48:200PM	Plasma	Ok	(null)
10	12:56:36:030PM	Plasma	Ok	(null)
11	01:18:56:327PM	Plasma	Ok	(null)
12	01:36:57:747PM	Plasma	Ok	(null)
13	01:54:31:420PM	Plasma	Ok	(null)
14	02:13:06:717PM	Plasma	Ok	(null)
15	02:32:20:233PM	Plasma	Ok	(null)
16	02:50:42:280PM	Plasma	Ok	(null)
17	03:09:34:030PM	Plasma	Ok	(null)
18	03:28:36:577PM	Plasma	Ok	(null)
19	03:50:29:890PM	Plasma	Ok	(null)
20	04:08:56:700PM	Plasma	Ok	(null)
21	04:28:31:187PM	Plasma	Ok	(null)
22	04:53:52:140PM	Plasma	Ok	(null)
23	05:12:56:360PM	Plasma	Ok	(null)
24	05:32:44:903PM	Plasma	Ok	(null)
25	05:52:14:840PM	Plasma	Ok	(null)