Miniproposals

Miniproposal: 049 Date Filed: 4/8/1994 Title: 2D Neutral Density Profile Measurements by Charge Exchange Recombination First Author: John Rice Session Leader: John Rice (shots 1-37)

Engineering Operator Run Comment

density/hirex

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Entered: Jul 7 2004 03:49:12:490PM

Author: To Be Determined

From: LEADER::RICE Date: 7-MAR-1995 17:37:01 Description: 950307 Run Summary Run Summary for 950307 A new shot record of 36 in a row was set. Two radial scans of HIREX were performed, the first at a density of nel=7e19, and the second at 5e19. At the higher density, it was difficult to observe an up-down asymmetry of the neutral deuterium density, presumably due to insufficient H-like argon at radii with high enough neutral density. Lowering the electron desnity slightly resulted in an increase of the central electron temperature to nearly 3 keV, and a dramatic up-down asymmetry was observed. X-ray emission from near the X-point was observed, from charge-exchange populated levels, and from radiative recombination continuum. Detailed profiles will be forthcoming. For the nel=5e19 sequence, the argon puff was 60ms wide at 90V, with 4 lbs in the plenum. The radiated power was not too high, and the molybdenum emission was surprisingly low at this density. The plasmas were very reproducible, thanks to judicious electron density programming. The experimental program committee can shovel dirt onto the late MP, 049A, but beware of resurrection.

Physics Operator Summaries

Entered: Jul 7 2004 04:36:53:457PM

Author: To Be Determined

Summary: 36 plasma attempts, 36 plasmas, 1 early disruption, 0 fizzles, 0 duds, 1 power supply test. From: PHYSOP::MARMAR Date: 7-MAR-1995 18:09:31 Description: Physics operator's run summary: 950307 950307 MP 049A, 2D Neutral Hydrogen Density Profiles EO Bertolino/Daigle PO Marmar SL Rice 2.5 hours ECDC in D2 (5:15 to 7:45 am) This run puts 049A to bed. We had multiple shots at each of two densities, (nl_04 = .5e20 and .7e20), with significant argon levels. Other parameters included Bt=5.3T, Ip=.8MA, D2 fill and puff (A side), Argon through B-side "lower". shot 1 was a PF test 2. Start from 950303025 with nl_04=.7e20, fill=2.0e-5, no argon, good plasma 3. enable argon, 25 msec at .3, 4psi in plenum, fill 2.2e-5, ok, H-modes 4. stretch flattop to 1.2 s.,disrupt late 5. wirehead twiddles, still disrupt early in rampdown 6. repeat 7. reduce strikepsi gain at .75 s, still disrupt at start of rampdown 8 reload shot 3, increase Argon pulse by 5 msec, good, disrupt at 175 kA 9. increase argon by 5 more msec, disrupt at 300 kA, ef1 fault just before disrupt 10 move prop gain decrease on wire 3 earlier (.45 s from .5), good shot, disrupt at 200 kA 11 move prop gain decrease on wire 3 earlier (.4 s from .45), increase Ar pulse by 5 more msec, good, disrupt at 300 kA 12 increase Ar pulse by 5 more msec, good, disrupt at 350 kA 13 no changes, some hards 14 fill = 2.3e-5, no hards, disrupt at 370 kA 15 increase late gas puff, hards came back 16 refill D2 plenum to 18 PSI, hards gone 17 fill 2.4e-5, good 18 repeat, good 19 tweak late ZCUR (program to -1 instead of 0 cm) 20 fill 2.3e-5, try ZCUR to +1 late, RCUR in a little faster at end, little or no change 21 add 5 msec to Ar pulse (now 50 msec) 22 lower fast ZCUR prop gain from 4 to 2 at 1.25 seconds, 5 more msec argon, disrupt at 500 kA 23 raise fast ZCUR prop gain from 2 to 6 at 1.25 s, undo shot 20 RCUR tweak, increase Ip rampdown rate slightly, adjust EF4 rampdown as well, disrupt at 430 kA 24 raise nl_04 to 1.0e20, reduce argon pulse by 15 msec, undo late ZCUR gain change, disrupt at 380 kA 25 lower nl_04 to .5e20, increase argon pulse by 20 msec, disrupt at 430 kA 26 change CLEARIN late (decrease), program nl_04 to drop a little sooner, disrupt at 450 kA 27 repeat, disrupt at 500 kA 28 twiddle RCUR and turn off strkpsi gain at 1.1s, program nl_04 to drop a little sooner, got rid of vertical wobble at end, but still disrupted at 520 kA 29 repeat 30 add a little deriv gain on nl_04, increase clearin late to avoid going limited so soon on rampdown, disrupt at 460 kA 31 decrease slow ZCUR gain late to attempt to avoid breaker trips, ok, disrupt at 460 kA 32 slow current rampdown 33 keep RCUR centered longer during rampdown, disrupt at 640 kA 34 twiddle with late RXL and ZXL programming, ramp RCUR in a little faster on rampdown, disrupt at 500 kA 35 twiddle with late ZCUR programming (don't go as high), disrupt at 480 kA 36 decrease clearin late, 37 eliminate final gas puff, increase argon pulse by 50 msec, disrupt early, a touch too much argon Hard x-rays started to appear in the middle of the run (shots 13 and 15). The combination of topping off the plenum at about 18 PSI and adding a small D2 puff late (using nl_04) eliminated this problem for the duration of the run. As a general rule, it appears to be useful to run the first shot of the day, after ECDC loads the walls, at a reduced fill pressure; after that, raising the pressure by about 15% worked well today. Summary: 36 plasma attempts, 36 plasmas, 1 early disruption, 0 fizzles, 0 duds, 1 power supply test. A typical Tuesday run.

Session Leader Comments

Physics Operator Comments

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	08:04:24:010AM	Test	Ok	coax test, efc test
2	08:38:56:680AM	Plasma	Ok	no faults
3	08:55:22:210AM	Plasma	Ok	no faults
4	09:09:42:620AM	Plasma	Ok	no faults
5	09:28:24:150AM	Plasma	Ok	no faults
6	09:37:57:690AM	Plasma	Ok	no faults
7	09:51:09:140AM	Plasma	Ok	no faults
8	10:03:09:510AM	Plasma	Ok	no faults
9	10:21:03:780AM	Plasma	Bad	ef1 comm fault
10	10:35:25:920AM	Plasma	Ok	no faults
11	10:48:04:540AM	Plasma	Ok	no faults
12	11:01:32:720AM	Plasma	Ok	no faults
13	11:14:14:210AM	Plasma	Ok	no faults
14	11:26:09:300AM	Plasma	Ok	no faults
15	11:40:18:060AM	Plasma	Ok	no faults
16	11:56:46:560AM	Plasma	Ok	no faults
17	12:08:09:230PM	Plasma	Ok	no faults
18	12:38:09:230PM	Plasma	Ok
19	01:01:24:470PM	Plasma	Ok	CoMM fault EF1U & OH1
20	01:13:46:390PM	Plasma	Ok	No Faults.
21	01:22:58:780PM	Plasma	Ok	No Faults.
22	01:36:01:860PM	Plasma	Ok	No Faults.
23	01:48:48:930PM	Plasma	Ok	No Faults.
24	02:02:14:020PM	Plasma	Ok	Comm fault OH1 EF1u OH2L
25	02:15:54:790PM	Plasma	Ok	No Faults.
26	02:27:45:870PM	Plasma	Ok	No Faults.
27	02:40:23:470PM	Plasma	Ok	Comm Fault OH1 EF1U oh2L
28	02:55:04:040PM	Plasma	Ok	No Faults.
29	03:07:04:930PM	Plasma	Ok	Comm fault OH1 OH2L EF1U
30	03:20:31:790PM	Plasma	Ok	Comm Fault OH1, OH@l EF1u
31	03:36:19:540PM	Plasma	Ok	No Faults.
32	03:54:32:800PM	Plasma	Ok	No Faults.
33	04:06:55:480PM	Plasma	Ok
34	04:19:22:440PM	Plasma	Ok	No Faults.
35	04:33:31:460PM	Plasma	Ok	No Faults.
36	04:44:58:310PM	Plasma	Ok	Comm Fault OH2L OH1
37	04:58:33:450PM	Plasma	Ok	No Faults.