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 1-18)

Engineering Operator Run Comment

2D neutral density

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Physics Operator Summaries

Entered: Jul 7 2004 04:36:52:473PM

Author: To Be Determined

Run 9412014 MP 049A PO report 2-D neutral density measurements. John Rice (SL), Steve Horne (PO) Vinnie B (EO) Run began with broken chopper; gate drive board again. Fixed quickly. Plan was to begin with limited plasmas (941208024). Were plagued by fizzles/duds which were initially attributed to a dirty machine, but were probably due at least in part to field errors traceable to the ef1l power supply tweak last week. I tuned out the power supply imbalance on shot 17 with asymmetric voltage programming; then sent Vinnie in to tweak the EF1U supply to be like the EF1L. (The tweak gives us more voltage, which is a good thing.) Compensated by symmetrizing the voltage programming, and that shot went as well. Since we now had two in a row, we end the run, vent machine, replace gate valve & cryopump. The segment 1 programming from shot 18 should be used to start the next run. Shot 1 load 941208024; NL7 <--- NL4 , dropped nl programmoing to 5.e19 fill 1.4 Fizzle. Probably related to power supply changes -- should have imported segment 1 from last shot. yesterday. Chopper is broken. Check gate drive board. It's possible that we could proceed without the chopper if it's seriously broken. 2 Chopper fixed (10 min.) Same parts as last time. (ON gate drive board). Frank suggests that once the pulse transformers saturate, the drain current might get too large. Should let Bill B look at it. Reloaded segment 1 from last shot yesterday, to collect up Wolfe's startup tweaks. Same fill. Fizzle. Some fluxihh analysis erros Fill to 1.2. No other changes. Plasma, ends with disruption, sparkles. Lots of nonthermal features and hard Xrays. 3 fill to 1.6e-5. move x-points out (vertically) 1 cm from 1.0 to 1.3 sec to try to kill the disruption. Fizzle. 4. Add .025 sec, 90V pulses to pulse_gas_1(argon) starting at .5 and .7 sec. Scatterplot shows br too positive on shot 3. fizzle. 5. drop br offset by .5 mt. Fill to 1.4e-5 Fizzle. 6 Fizzle. 7 Fill to 1.2. Plasma, disruption still there. 8. Fill to 1.3 Rampdown is already quite gentle. Start the x-point ramps earlier and more -- now 2 cm starting at .95 sec. Fizzle. 9. make br more negative by .5 mt. now at +5.e-3 Fill to 1.2e-5 again. dud!. br, bz, etc look ok. mflux compared to last shot yesterday looks better. 10 fill to 1.4. Yuichi just told me that yesterday we had RF assist; today not. Fizzle. 11 fill to 1.2. Dud. 12 fill to 1.6. This is where we ran yesterday. 13 fill to 1.3 Plasma, still nasty disruption. 14 Try to fix up the ef1 demand. Comparing to shot 941208024, the null is worse. Try a) drop ic_ef1 gains from 5 back to 2 at -50 msec, to reduce the ripple, and b) match voltage to old shot (Phys_m_out scope) so will still get the current. Also raise density to 8.e-13. fizzle Scatterplot comparison to run 941208 shows we need br more + by at least 1 more mt. 15. the oscillation in ef1 is better. Now make ef1l V more + by 10 v. Fizzle 16 Raise br offset back to 6.e-3. Fizzle, but breakdown was earlier. Run it again. 17 Plasma, with rampdown. 18 Send Vinnie out to make ef1U like ef1L. Copy ef1L V to ef1U. Good Plasma, with rampdown! mflux shows very nice null. Stop run here (1:00)

Session Leader Comments
Dec 14 1994 09:00:09:160AM	941214001	John Rice	try running 941208024, but with lower density fill pressure 1.4 e-5 T fizzle
Dec 14 1994 09:19:25:420AM	941214002	John Rice	fizzle
Dec 14 1994 09:34:28:780AM	941214003	John Rice	plasma, with hard x-rays, and disruption fill 1.2 e-5
Dec 14 1994 09:48:50:410AM	941214004	John Rice	fizzle fill 1.6 e-5
Dec 14 1994 09:51:40:610AM	941214004	John Rice	fizzle fill 1.6 e-5
Dec 14 1994 09:56:36:420AM	941214005	John Rice	fizzle fill 1.6 e-5
Dec 14 1994 10:08:30:560AM	941214005	John Rice	fizzle fill 1.4 e-5
Dec 14 1994 10:08:56:890AM	941214006	John Rice	fizzle fill 1.4 e-5
Dec 14 1994 10:25:21:460AM	941214007	John Rice	plasma, some hards, disruption, moly fill 1.2 e-5
Dec 14 1994 10:38:12:590AM	941214008	John Rice	fizzle fill 1.3 e-5
Dec 14 1994 10:48:29:970AM	941214009	John Rice	fizzle fill 1.2 e-5
Dec 14 1994 11:03:07:690AM	941214010	John Rice	fizzle fill 1.4 e-5
Dec 14 1994 11:12:32:220AM	941214011	John Rice	fizzle fill 1.6 e-5
Dec 14 1994 11:37:05:870AM	941214012	John Rice	fizzle fill 1.6 e-5
Dec 14 1994 11:38:18:580AM	941214013	John Rice	plasma, hards, moly fill 1.3 e-5
Dec 14 1994 11:41:21:580AM	941214013	John Rice	plasma, hards, moly fill 1.3 e-5
Dec 14 1994 11:55:56:220AM	941214014	John Rice	fizzle fill 1.3 e-5
Dec 14 1994 12:11:06:480PM	941214015	John Rice	fizzle fill 1.3 e-5
Dec 14 1994 12:25:33:260PM	941214016	John Rice	fizzle fill 1.3 e-5
Dec 14 1994 12:36:37:410PM	941214017	John Rice	plasma, higher density, lower hards fill 1.3 e-5
Dec 14 1994 12:51:51:330PM	941214018	John Rice	plasma, higher density fill 1.3 e-5

Physics Operator Comments

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	08:38:34:150AM	Plasma	Bad	chopper fuse blown
2	09:17:54:520AM	Plasma	Ok	no faults
3	09:29:33:470AM	Plasma	Ok	no faults
4	09:47:06:990AM	Plasma	Ok	no faults
5	09:55:25:550AM	Plasma	Ok	no faults
6	10:07:04:060AM	Plasma	Ok	no faults
7	10:18:04:440AM	Plasma	Ok	no faults
8	10:36:33:660AM	Plasma	Ok	no faults
9	10:45:52:130AM	Plasma	Ok	no faults
10	10:59:15:200AM	Plasma	Ok	no faults
11	11:10:35:800AM	Plasma	Ok	no faults
12	11:26:02:730AM	Plasma	Ok	no faults
13	11:35:00:310AM	Plasma	Ok	no faults
14	11:53:15:760AM	Plasma	Ok	no faults
15	12:09:27:640PM	Plasma	Ok	no faults
16	12:22:17:710PM	Plasma	Ok	no faults
17	12:30:14:530PM	Plasma	Ok	no faults
18	12:48:51:260PM	Plasma	Ok	oh1 comm fault after disruption