Miniproposals

Miniproposal: Date Filed: Title: First Author: Session Leader: Steve Golovato (shots 1-31)

Engineering Operator Run Comment

icrf heating

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Entered: Jul 7 2004 03:49:12:040PM

Author: To Be Determined

run summary - 950124 --------------------- SL: golovato PO: snipes EO: silva/bertolino Goals- (1) continue density scan at high power to higher densities nl04 = 0.6, 0.8, 1.0e20 done, do 1.2, 1.5e20 start with shot 950120019 where nl04=1.e20 (2) vary (increase) outer gap, observe changes in loading, plasma behavior (H-mode threshold). scan density. (3) if time, try H puffing to vary minority fraction. This was not one of the usual successful rf runs we've become accustom to. We only accomplished part of goal (2). We had reconfigured the e-port transmission line over the weekend to reduce voltages in the tuners. This was successful, with the voltages down by a factor of 2 and the loading up be a factor of 4, now twice the d-port loading. Remember that this is NOT the plasma loading but rather the resistance we must transform (match) to 50 Ohms using the tuners. We started with shot 19 from last friday, where nl04=1.e20 and the outer gap was about 7-8 mm. Since d-port was unchanged, it was matched from the start, while we had to tune e-port. The first 6 shots were lost to fizzles, duds, and tests. Once we got going we had trouble with the arc detection circuits for both transmitters, which had been worked on since friday. We were tripping when there weren't arcs because they were miss-set to be too sensitive. By shot 19, we managed to get about 1.2 MW on each antenna. At this point, we decided to increase the outer gap rather than raise the density. The loading was high on both antennas and there seemed to be some strong interactions with the edge plasma, as evidenced by glowing and occasional emissions from the antennas as seen on the tv monitors. From shot 20 on we ran with an outer gap of about 1.6 cm. Joe Snipes struggled to get constant rather than ramping inner and outer gaps, causing some shot-to-shot variations which made tuning somewhat difficult. However he solved the problem by shot 26. In the end we had good tunes and good loading with the larger outer gap, with d-port running reliably at 1.5 MW as usual, but e-port limited to about 1.0 MW, apparently by an arc. We did see some short H-mode transitions, but nothing as spectacular as was seen last friday. The reconfiguring of e-port did seem to solve another important problem, rf noise on hirex and pcx. It may be the lower voltages, that the dc break is now moved to a lower voltage point in the line, or that a loose bolt and some arcing was fixed in the dc break, or all three. The PCX saw enhanced flux compared to similar shots on friday, in particular on shots 24 and 25. It was not clear why but we also observed a change in loading, indicating changes in the edge plasma. The session leader shot-to-shot summary can be found in the logbook under the session_leader topic. Details on technical difficulties can be found in the physics operator summary. The shot summary was: 22 plasmas 7 fizzles 1 dud 1 ps test

Physics Operator Summaries

Entered: Jul 7 2004 04:36:52:927PM

Author: To Be Determined

High Power ICRF Run Session Leader: Steve Golovato Physics Operator: Joseph Snipes Engineering Operator: Frank Silva Continue near where 950120 left off, copying shot 950120019. Plan is to raise the density and increase the outer gap. Overall, the run did not go very well, but not horribly either. For the first third of the run, we were plagued with breakdown problems. Small changes in EF4 current and OH1 voltage were made and we finally got plasma, which then went away as time went on. So, I gradually reprogrammed the changes back to last Friday's startup and then the plasmas came regularly until the last shot, which also fizzled rather inexplicably. It bounced, but it was not clear why. Perhaps, we needed to wait longer for the gas to pump out. The RF power did not go very well either with constant small problems. Shots 24 and 25 had very short ELM-free H-modes during the RF at power levels of between 2 and 2.5 MW lasting just over 20 msec. Run Summary: Shot,Duration(s),Ipmax(MA) Shot,Duration(s),Ipmax 1 0.000 0.018 2 0.000 0.018 3 0.000 0.029 4 0.000 0.032 5 0.000 0.032 6 0.000 0.029 7 1.393 0.830 8 0.000 0.019 9 1.412 0.828 10 1.431 0.833 11 1.268 0.828 12 0.000 0.026 13 1.218 0.828 14 1.206 0.825 15 1.240 0.828 16 1.224 0.830 17 1.188 0.830 18 1.338 0.833 19 1.377 0.835 20 1.355 0.833 21 1.352 0.835 22 1.325 0.833 23 1.325 0.835 24 1.322 0.838 25 1.395 0.833 26 1.293 0.835 27 1.383 0.835 28 1.384 0.835 29 1.358 0.833 30 1.395 0.838 31 0.000 0.042 Finished summary for 950124 Total of 31 shots. 31 shots. 22 plasmas. 7 fizzles. 2 PF tests Shot 1: PF test shot. OK. Shot 2: Frank's error. Another PF test. Shot 3: Fizzle! Shot 4: Raised prefill to 1.7 x 10^-5 Torr. Fizzle! Shot 5: Dropped OH1 voltage at 15 ms by 50 V to 50 V to attempt to correct the vertical field at breakdown. Fizzle! Shot 6: Dropped OH1 voltage at 10 ms by 50V to 50 V again to attemp to correct the vertical field at breakdown. Fizzle! Shot 7: Lowered EF4 before t=0 from -1085 to -1100 A. Lowered prefill to 1.5 x 10^-5 Torr. Decent plasma! Shot 8: Repeat. Fizzle! Shot 9: Returned OH1 voltage programming to what it was on 950120. Plasma. Shot 10: Tweaked OH1 voltage programming in between 10 - 15 ms. Raised prefill to 1.7 x 10^-5 Torr. Decent plasma. Shot 11: Ar puff enabled at 0.3 sec. Modified RCUR in rampdown to try to eliminate MARFE. Decent plasma! Shot 12: Returned RCUR programming to previous values, since the rampdown got worse on shot 11. Fizzle! Shot 13: Returned EF4 current to -1085 A before breakdown. Good shot! Shot 14: Repeat. Good shot. Shot 15: Repeat. Good shot. Shot 16: Changed rampdown to be more consistent with flattop phase. Good shot. Finally got RF power up. Shot 17: Good shot. Shot 18: Modified rampdown phase to try to keep the density down by not pushing the plasma against the inner wall. Good shot! Shot 19: Tweaked CLEARIN to keep the plasma away from the inner wall during the rampdown. Good shot. Shot 20: Reduced RCUR from 0.67 m to 0.665 m to increase the outer gap. Good shot. Shot 21: Increased RCUR after 1 sec to keep the plasma away from the inner wall during rampdown. Also raised ZXL during rampdown up 6 cm to reduce the elongation. Good shot. Shot 22: Repeat. Good shot. Shot 23: Modified rampdown again to reduce elongation and increase the inner gap. Ramped up the CLEARIN to -6 mm to try to counteract the ramp down of the inner gap during the flattop. Good shot. Shot 24: Modified rampdown again to increase the inner gap by increasing CLEARIN and raising ZXL to 10 cm. Good shot. Short H-mode that tripped the RF power. Shot 25: Modified rampdown to further increase the inner gap by increasing CLEARIN. Also increased the ramp on CLEARIN during the flattop to try to maintain a constant inner gap. Good shot. Short H-mode that tripped the RF power. Shot 26: Moved integral gain on CLEARIN to ramp up from 0.3 to 0.5 sec to eliminate accumulated error that was apparently causing the ramp in the inner gap. Also, flattened requested CLEARIN assuming this will work. Good shot, but the inner gap is ramping again. Shot 27: Reduced ZXL and RXL during rampdown to eliminate jump at 1.12 sec in the inner gap. Good shot. Shot 28: Repeat. Good shot. Shot 29: Repeat. Good shot. Shot 30: Repeat. Good shot. Shot 31: Moved ZCUR down to its flattop value during the rampdown. Fizzle.

Session Leader Comments
Jan 24 1995 09:01:18:870AM		Steve Golovato	run goals - (1) continue density scan at high power to higher densities nl04 = 0.6, 0.8, 1.0e20 done, do 1.2, 1.5e20 start with shot 950120019 where nl04=1.e20 (2) vary (increase) outer gap, observe changes in loading, plasma behavior (H-mode threshold). scan density. (3) if time, try H puffing to vary minority fraction.
Jan 24 1995 09:01:58:130AM	950124001	Steve Golovato	950124001 - pf test
Jan 24 1995 09:02:43:950AM	950124002	Steve Golovato	950124002 - dud. engineering operator error.
Jan 24 1995 09:03:28:490AM	950124003	Steve Golovato	950124003 - fizzle.
Jan 24 1995 09:08:28:950AM	950124003	Steve Golovato	950124003 - fizzle.
Jan 24 1995 09:30:04:440AM	950124004	Steve Golovato	950124004 - fizzle again.
Jan 24 1995 09:56:26:950AM	950124005	Steve Golovato	950124005 - fizzled.
Jan 24 1995 10:26:59:480AM	950124007	Steve Golovato	950124007 - good plasma. xmitter#2 didn't run. #1 interrupted except at low power. tune was ok, trip is too sensitive.
Jan 24 1995 10:27:35:540AM	950124008	Steve Golovato	950124008- fizzled again.
Jan 24 1995 10:33:18:180AM	950124008	Steve Golovato	950124008- fizzled again.
Jan 24 1995 10:51:03:760AM	950124009	Steve Golovato	950124009- plasma. both ran but #2 trip is also too sensitive, no useful data for tuning.
Jan 24 1995 11:09:13:160AM	950124010	Steve Golovato	950124010- good plasma. both still not tuned but some data available for tuning.
Jan 24 1995 11:37:26:940AM	950124011	Steve Golovato	950124011- good plasma. d-port tuned, e-port close but power still very low. e-port loading much higher with reconfigured coax, even higher than d-port. this is not plasma loading, it is the load that must be matched to 50 ohms by the tuners.
Jan 24 1995 11:38:23:500AM	950124012	Steve Golovato	950124012- fizzle.
Jan 24 1995 12:15:02:650PM	950124013	Steve Golovato	950124013- plasma. tuning better but some problems with arc detection level. xmitters tripping when they shouldn't.
Jan 24 1995 12:16:06:960PM	950124014	Steve Golovato	950124014- plasma. almost there. 400kw on e-port, 150kw on d-port. .
Jan 24 1995 12:35:06:710PM	950124015	Steve Golovato	950124015- plasma. e-port tuned, 550kw. d-port 125kw. .
Jan 24 1995 12:47:59:300PM	950124016	Steve Golovato	950124016- plasma. e-port .8mw, d-port .3mw .
Jan 24 1995 01:11:26:870PM	950124017	Steve Golovato	950124017- plasma. d-port 1.2mw, e-port 0.8mw, not overlapped. e-port arc detection needs to be desensitized. .
Jan 24 1995 01:25:14:800PM	950124018	Steve Golovato	950124018- plasma. d-port 1.1mw, e-port 1.1mw, with some interrupts. .
Jan 24 1995 01:43:00:770PM	950124019	Steve Golovato	950124019- plasma. d-port 1.251mw, e-port mistuned at high power. .
Jan 24 1995 01:45:01:660PM	950124019	Steve Golovato	950124019- plasma. e-port 1.25mw. .
Jan 24 1995 01:59:25:340PM	950124020	Steve Golovato	950124020- increase outer gap by increasing rcur by about 6mm. this should increase outer gap from .7-.8cm to about 2cm. no e-port power, may have crowbarred last shot. d-port at 1mw. .
Jan 24 1995 02:35:22:000PM	950124021	Steve Golovato	950124021 - 1.3mw from d-port, .6mw from e-port. still tuning to larger outer gap of about 1.7cm.
Jan 24 1995 03:03:48:870PM	950124022	Steve Golovato	950124022 - e-port loading now twice d-port. 1.6mw in d-port, e-port arced at 1.1mw at .72s.
Jan 24 1995 03:06:05:610PM	950124023	Steve Golovato	9950124023- plasma. d-port 1.5mw, e-port tripped at 800kw but was tuned.
Jan 24 1995 03:22:38:110PM	950124024	Steve Golovato	9950124024- good shot, got short h-mode, e-port tripped at h-mode transition. adjusted tuning to mathc better at transition.
Jan 24 1995 03:41:54:040PM	950124025	Steve Golovato	9950124025- still losing e-port at h-mode, keep trying to tune to h-mode loading.
Jan 24 1995 03:51:53:850PM	950124026	Steve Golovato	9950124026- #2 crowbarred, probably last shot. #1 tripped at 1.5mw. little or no rf.
Jan 24 1995 03:57:38:840PM	950124026	Steve Golovato	950124026- #2 crowbarred, probably last shot. #1 tripped at 1.5mw. little or no rf. the gaps have been changing over the last few shots, causing us to tune to a moving target.
Jan 24 1995 04:23:33:500PM	950124027	Steve Golovato	950124027- finally full puses on both antennas. need to tune a little.
Jan 24 1995 04:26:18:460PM	950124028	Steve Golovato	950124028- good tunes, but e-port trips at .82 s.
Jan 24 1995 04:50:49:800PM	950124029	Steve Golovato	950124029- brought up e-port power sooner so it tripped sooner. looks like an arc.
Jan 24 1995 04:56:26:770PM	950124029	Steve Golovato	950124029- brought up e-port power sooner so it tripped sooner. looks like an arc.
Jan 24 1995 04:57:46:690PM	950124030	Steve Golovato	950124030- e-port tripped when power ramped slightly at .83 s. this didn't look like an arc, no jump in reflected power.
Jan 24 1995 05:02:56:740PM	950124031	Steve Golovato	950124031- fizzle!!!!

Physics Operator Comments
Jan 24 1995 08:45:59:320AM	950124001	Joseph Snipes	High Power ICRF Run Session Leader: Steve Golovato Physics Operator: Joseph Snipes Engineering Operator: Frank Silva Continue Friday's RF run starting with shot 950120019. Plan is to raise the density and increase the outer gap. Shot 1 PF test shot. OK.
Jan 24 1995 09:00:19:690AM	950124002	Joseph Snipes	Shot 2 Try a repeat of shot 950120019. Frank's error. Another PF test.
Jan 24 1995 09:34:09:260AM	950124003	Joseph Snipes	Shot 3 Fizzle!
Jan 24 1995 09:34:41:870AM	950124004	Joseph Snipes	Shot 4 Fizzle!
Jan 24 1995 09:51:55:340AM	950124005	Joseph Snipes	Shot 5 Dropped OH1 voltage at 0.015 sec by 50 V to attempt to correct the vertical field error at breakdown. Fizzle!
Jan 24 1995 10:08:04:560AM	950124006	Joseph Snipes	Shot 6 Dropped OH1 voltage at 0.01 sec by 50 V as well to attempt to correct the vertical field error at breakdown. Fizzle!
Jan 24 1995 10:18:48:210AM	950124007	Joseph Snipes	Shot 7 Lowered EF4 current from -1085 to -1100 A before t = 0. Lowered prefill to 1.5 x 10^-5 Torr. Got plasma. Decent shot!
Jan 24 1995 10:26:14:830AM	950124008	Joseph Snipes	Shot 8 Repeat. Fizzle!
Jan 24 1995 10:54:19:460AM	950124009	Joseph Snipes	Shot 9 Returned OH1 voltage programming to what it was last Friday. Try again. O.K. plasma, but breakdown still shaky.
Jan 24 1995 11:00:45:560AM	950124010	Joseph Snipes	Shot 10 Tweaked OH1 voltage programming between 10 and 15 ms to smooth out the rapid change in voltage. Increased prefill to 1.7 x 10^-5 Torr to attempt to avoid the hard x rays. Decent plasma.
Jan 24 1995 11:25:58:210AM	950124011	Joseph Snipes	Shot 11 Argon gas puff enabled. There will be a 33 ms puff at 90 V starting at 0.3 s. Modified rampdown RCUR to push the plasma inward against the inner wall to try to eliminate the MARFE in the rampdown. Decent plasma, but rampdown was worse.
Jan 24 1995 11:41:47:330AM	950124012	Joseph Snipes	Shot 12 Returned rampdown RCUR to previous settings. Fizzle!
Jan 24 1995 11:59:49:720AM	950124013	Joseph Snipes	Shot 13 Returned EF4 programming to what it was last Friday on the theory that the machine is now cleaning up and can return to the previously good values. Good shot!
Jan 24 1995 12:45:46:500PM	950124014	Joseph Snipes	Shot 14 Repeat. Good shot.
Jan 24 1995 12:46:24:210PM	950124015	Joseph Snipes	Shot 15 Repeat. Good shot.
Jan 24 1995 12:49:20:120PM	950124016	Joseph Snipes	Shot 16 Modified rampdown to be consistent with flattop phase. RCUR, ZXL, RXL, and CLEARIN all had a small jump at the segment switch time of 1 sec. Good shot! Finally got nearly 1 MW of ICRF power.
Jan 24 1995 01:14:22:580PM	950124017	Joseph Snipes	Shot 17 Repeat. Good shot.
Jan 24 1995 01:25:12:430PM	950124018	Joseph Snipes	Shot 18 Modified current rampdown to try to keep an elongated plasma from going against the inner wall. The idea being to keep the density from going up as the plasma ramps down. Good luck! Good shot!
Jan 24 1995 01:46:02:750PM	950124019	Joseph Snipes	Shot 19 Tweaked clearin late to try to keep the plasma away from the inner wall during the current rampdown. Good shot!
Jan 24 1995 02:02:33:390PM	950124020	Joseph Snipes	Shot 20 Reduced RCUR from 0.67 m to 0.665 m to try to increase the outer gap. Good shot.
Jan 24 1995 02:31:10:600PM	950124021	Joseph Snipes	Shot 21 Increased RCUR after 1 sec to keep the plasma away from the inner wall during rampdown. Also raised ZXL during rampdown up 6 cm to reduce the elongation. Elminated ramp in CLEARIN during the flattop and eliminated most of the ramp in RXL to try to keep the inner gap constant during the flattop. Good shot.
Jan 24 1995 02:41:30:370PM	950124021	Joseph Snipes	Shot 22 Repeat. Good shot.
Jan 24 1995 02:55:46:880PM	950124023	Joseph Snipes	Shot 23 Modified rampdown again to reduce elongation and increase the inner gap. Ramping up the CLEARIN to -6 mm to try to counteract the ramp down of the inner gap during the flattop. Good shot.
Jan 24 1995 03:12:21:140PM	950124024	Joseph Snipes	Shot 24 Modified rampdown again to increase the inner gap by increasing CLEARIN and raising ZXL to 10 cm. Good shot.
Jan 24 1995 03:39:17:510PM	950124025	Joseph Snipes	Shot 25 Modified rampdown again to increase the inner gap by increasing CLEARIN. Also increased CLEARIN ramp during the flattop to try to keep a constant inner gap to -1 mm. Good shot.
Jan 24 1995 03:59:21:340PM	950124026	Joseph Snipes	Shot 26 Moved integral gain on CLEARIN to ramp up from 0.3 to 0.5 sec to eliminate accumulated error that was apparently causing the ramp in the inner gap. Also flattened requested CLEARIN assuming this will work. Good shot. However, the old ramp in the inner gap is back. So, the integral gain was not the problem. Let it be.
Jan 24 1995 04:25:42:680PM	950124027	Joseph Snipes	Shot 27 Reduced ZXL and RXL during rampdown to eliminate jump at 1.12 sec in the inner gap. Good shot.
Jan 24 1995 04:26:15:720PM	950124028	Joseph Snipes	Shot 28 Repeat. Good shot.
Jan 24 1995 04:51:42:150PM	950124029	Joseph Snipes	Shot 29 Repeat. Good shot.
Jan 24 1995 04:52:40:170PM	950124030	Joseph Snipes	Shot 30 Repeat. Good shot.
Jan 24 1995 05:16:54:080PM	950124031	Joseph Snipes	Shot 31 Moved ZCUR down to its flattop value during the rampdown. Fizzle!
Jan 24 1995 05:23:23:820PM	950124031	Joseph Snipes	Overall, the run did not go very well, but not horribly either. For the first third of the run, we were plagued with breakdown problems. Small changes in EF4 current and OH1 voltage were made and we finally got plasma, which then went away as time went on. So, I gradually reprogrammed the changes back to last Friday's startup and then the plasmas came regularly until the last shot, which also fizzled rather inexplicably. It bounced, but it was not clear why. Perhaps, we needed to wait longer for the gas to pump out. The RF power did not go very well either with constant small problems.

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	08:35:53:630AM	Test	Ok	felt metal test
2	08:52:32:190AM	Plasma	Ok	power suplies off no plasma fjs operator error
3	09:01:38:140AM	Plasma	Ok
4	09:23:06:820AM	Plasma	Ok	good shot no plasma
5	09:39:02:210AM	Plasma	Ok	no faults
6	09:54:27:010AM	Plasma	Ok	no faults
7	10:11:12:680AM	Plasma	Ok	no faults
8	10:23:30:060AM	Plasma	Ok	no faults
9	10:39:53:080AM	Plasma	Ok	nofaults plasma
10	10:57:11:640AM	Plasma	Ok	no faults plasma
11	11:14:43:800AM	Plasma	Ok	no faults plasma
12	11:31:07:390AM	Test	Ok	no faults
13	11:45:07:480AM	Plasma	Ok	no faults plasma
14	12:04:52:810PM	Plasma	Ok	no faults p[lasma
15	12:24:37:620PM	Plasma	Ok	no faults plasma
16	12:42:00:290PM	Plasma	Ok	no faults plasma
17	12:58:05:170PM	Plasma	Ok	no faults
18	01:17:17:260PM	Plasma	Ok	no faults
19	01:36:34:030PM	Plasma	Ok	no faults
20	01:51:59:670PM	Plasma	Ok	no faults
21	02:18:55:940PM	Plasma	Ok
22	02:32:55:210PM	Plasma	Ok	no faults
23	02:52:56:000PM	Plasma	Ok	no faults
24	03:10:39:470PM	Plasma	Ok	no faults
25	03:28:29:120PM	Plasma	Ok	no faults
26	03:44:02:610PM	Plasma	Ok	no faults
27	04:01:07:450PM	Plasma	Ok	no faults
28	04:16:43:480PM	Plasma	Ok	no faults
29	04:31:24:660PM	Plasma	Ok	no faults
30	04:46:48:910PM	Plasma	Ok	no faults
31	05:01:18:410PM	Plasma	Ok	no faults