Miniproposals

Miniproposal: Date Filed: Title: First Author: Session Leader: Yuichi Takase (shots 1-24)

Engineering Operator Run Comment

first run after vac break

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Entered: Jul 7 2004 03:49:11:693PM

Author: To Be Determined

Session Leader's Run Summary for 941216 Run SL: Takase PO: Snipes EO: Bertolino The run objective was E-port antenna (B4C coated FS) commissioning: 1. to establish plasma tuning 2. antenna conditioning into plasma The target plasma was an inner-wall limited, mid-plane centered, high triangularity plasma we developed last week. Objective 1. was accomplished. Some more piggybacking will be needed to complete the tuner calibration, which will enable "one-shot matching". We need to continue working on Objective 2. We had 4 shots to raise the power (shots 021-024) after acceptable plasma tuning was established. We seem to be able to inject 0.5 MW reliably, and a little over 1 MW was achieved for a short time. Higher power pulses (> 0.5 MW) tend to end in what we think is an antenna arc, visible on the TV as a bright flash (don't be alarmed, this is why we need to condition the antenna with plasma, and it's clear we need some more time to contion). PLEASE BE AWARE THAT THE POWER LEVELS QUOTED HERE ARE NOT OFFICIAL YET! (they can be off by a factor of two). Because a drive signal reconfiguration was made to enable two-antenna operation, we also scanned the D-port antenna power (up to 1.9 MW) to establish a correspondence table between the programmed voltage and the RF power into the plasma (for a particular loading).

Physics Operator Summaries

Entered: Jul 7 2004 04:36:52:490PM

Author: To Be Determined

Overall, it was a reasonably successful run despite problems with the EF1L power supply that led to a large number of fizzles and some later control problems. Problems with EF1 at breakdown led us to begin to use integral control for the EF1s. At first, we integrated from -0.3 sec to 0 with a gain of 1. This turned out to be too much. It was backed off toward the end of the run to start at -0.1 sec and then worked fine. We also tried to eliminate the late disruptions in the current rampdown by decreasing the proportional gain on the fast ZCUR (wire 3). It does not seem to have had much effect, since the Z oscillation around 1.2 sec was still there on the last shot, though it seems to come and go. Also, the cross-over of the OH1 supply at about 0.3 to 0.35 sec leads to some jumps in the loop voltage and changes in the radiation signals (bolometer, H alpha, Z meter) indicating that some impurities may be coming into the plasma at that time. This should be looked into and corrected. At the end of the day, the RF coupling was successful and that was the purpose of the run. Because of yesterday's opening, the run started late and because of Navratil's seminar, the run ended early. Still, there were 24 shots, 17 plasmas, and 7 fizzles. Shot,Duration(s),Ipmax(MA) Shot,Duration(s),Ipmax 1 0.000 0.032 2 0.000 0.037 3 0.931 0.838 4 0.000 0.024 5 0.907 0.822 6 1.454 0.822 7 1.456 0.822 8 1.451 0.822 9 0.402 0.466 10 0.000 0.039 11 0.000 0.039 12 0.000 0.037 13 1.442 0.822 14 0.399 0.683 15 1.363 0.825 16 1.368 0.825 17 0.000 0.024 18 1.373 0.830 19 1.362 0.822 20 1.359 0.825 21 1.374 0.822 22 1.380 0.822 23 1.363 0.828 24 1.375 0.822

Session Leader Comments
Dec 16 1994 09:19:46:300AM	941216001	Yuichi Takase	Today's run: E port Antenna Commissioning (Tuning + Conditioning) Start from 941214018 Shot 001: Fizzle
Dec 16 1994 09:34:34:080AM	941216002	Yuichi Takase	Shot 002: Fizzle
Dec 16 1994 10:01:24:620AM	941216003	Yuichi Takase	Shot 003: plasma (disrupted @ 0.9s) Starting to tune.
Dec 16 1994 10:50:02:700AM	941216004	Yuichi Takase	Shot 004: fizzle
Dec 16 1994 10:53:16:530AM	941216005	Yuichi Takase	Shot 005: plasma (disrupt @ 0.9s)
Dec 16 1994 10:53:58:350AM	941216006	Yuichi Takase	Shot 006: plasma RF tripping
Dec 16 1994 11:36:48:490AM	941216007	Yuichi Takase	Shot 007: plasma Started to get tuning data. nel_04=0.8; R_L=2.4Ohms (low loading)
Dec 16 1994 12:08:24:580PM	941216008	Yuichi Takase	Shot 008: plasma nel_04=0.95; R_L=7Ohms.
Dec 16 1994 12:09:00:570PM	941216009	Yuichi Takase	Shot 009: plasma died early (0.4s)
Dec 16 1994 12:09:40:920PM	941216010	Yuichi Takase	Shot 010: fizzle
Dec 16 1994 12:28:50:840PM	941216011	Yuichi Takase	Shot 011: fizzle
Dec 16 1994 12:43:17:330PM	941216012	Yuichi Takase	Shot 012: fizzle
Dec 16 1994 01:41:18:870PM	941216013	Yuichi Takase	Shot 013: plasma nel_04=1.0, R_L=6Ohms
Dec 16 1994 01:42:03:320PM	941216014	Yuichi Takase	Shot 014: plasma died early (0.4s)
Dec 16 1994 01:56:51:550PM	941216015	Yuichi Takase	Shot 015: plasma nel_04=1.0; R_L=5Ohms
Dec 16 1994 02:05:16:720PM	941216016	Yuichi Takase	Shot 016: plasma nel_04=1.0; R_L=?Ohms (bad tune)
Dec 16 1994 02:12:42:180PM	941216017	Yuichi Takase	Shot 017:fizzle
Dec 16 1994 02:37:36:900PM	941216018	Yuichi Takase	Shot 018: plasma 1.9MW from D port E port didn't go
Dec 16 1994 03:00:38:270PM	941216019	Yuichi Takase	Shot 019: plasma no power from D port nel=1.0; R_L=5.5Ohms E port almost tuned
Dec 16 1994 03:14:53:360PM	941216021	Yuichi Takase	Shot 021: plasma no power from D port (tripping) nel=1.0; R_L=6->4Ohms Refl=5%->25%; Pf/Pr=160/35kW
Dec 16 1994 03:32:07:960PM	941216021	Yuichi Takase	Shot 021: plasma nel=1.0; R_L=4Ohms E port Pf/Pr=1.3/p.3MW D port 0.17/0.035MW
Dec 16 1994 03:43:26:520PM	941216022	Yuichi Takase	Shot 022: plasma nel=1.0; R_L=4Ohms E port Pf/Pr=0.7/0.15MW D port 0.40/0.08MW
Dec 16 1994 03:58:39:870PM	941216023	Yuichi Takase	Shot 023: plasma nel=1.0; R_L=4Ohms moved RCUR out 5mm E port Pf/Pr=0.9/0.1MW D port 0.75/0.08MW
Dec 16 1994 05:31:22:470PM	941216024	Yuichi Takase	Shot 024: plasma nel=1.0; R_L=6Ohms moved RCUR out another 5mm outer gap=1cm E port Pf/Pr=0.6/0.03MW D port 1.2/0.07MW

Physics Operator Comments
Dec 16 1994 10:19:28:530AM	941216001	Joseph Snipes	Shot 1 Fizzle!
Dec 16 1994 10:20:16:170AM	941216002	Joseph Snipes	Shot 2 Fizzle!
Dec 16 1994 10:26:28:520AM	941216003	Joseph Snipes	Shot 3 Got plasma, but disrupted at about 0.95 sec. The EF2 power supply current limit was set to 3 kA when it should have been 4 kA. The railing of the power supply apparently led to plasma control problems.
Dec 16 1994 10:27:02:150AM	941216004	Joseph Snipes	Shot 4 Fizzle!
Dec 16 1994 10:28:54:870AM	941216005	Joseph Snipes	Shot 5 Got plasma, but there was an EF1L crowbar that brought the plasma down early and led to a disruption at 0.9 sec.
Dec 16 1994 10:59:54:470AM	941216006	Joseph Snipes	Shot 6 Got plasma and it lasted quite long. Thrashing around 0.5 sec may be due to EF2 reaching its current limit. So, for the next shot, we will move the upper X point RXU from -3.5 cm to -3.0 cm and the RXL from -2.5 cm to -3.0 cm.
Dec 16 1994 11:03:42:600AM	941216007	Joseph Snipes	Shot 7 Good plasma!
Dec 16 1994 11:37:15:000AM	941216008	Joseph Snipes	Shot 8 Checking EF1 power supply for 15 minutes before this shot. Then, raising the density from 8 x 10^19 m^-2 to 9 x 10^19 m^-2. Good shot!
Dec 16 1994 11:56:41:350AM	941216009	Joseph Snipes	Shot 9 Raising the density from 9 x 10^19 m^-2 to 1 x 10^20 m^-2. EF1L power supply failure. Plasma died early around 0.15 sec.
Dec 16 1994 12:27:25:580PM	941216010	Joseph Snipes	Shot 10 Fizzle!
Dec 16 1994 12:36:38:850PM	941216011	Joseph Snipes	Shot 11 Fizzle! Wires 11 and 12 (EF1U,L) on integrator channel C. Integral gain on EF1U and EF1L from -0.2 sec to 0 sec with a gain of 1 for shot 12.
Dec 16 1994 01:09:47:170PM	941216012	Joseph Snipes	Shot 12 Fizzle! For shot 13, we reduced the OH1 voltage by 25 V and OH2U and L by 5 V. Changed integrator on EF1s to start at -0.3 sec and changed the gain from 2 to 3. Moved the proportional gain step down to -0.2 sec. The motivation for the OH1 and OH2 changes was to reduce the current rise since it seems to be increasing too rapidly. The EF1 changes are to make us less dependent on random changes in the EF1 power supply.
Dec 16 1994 01:15:53:840PM	941216013	Joseph Snipes	Shot 12 Fizzle! For shot 13, we reduced the OH1 voltage by 25 V and OH2U and L by 5 V. Changed integrator on EF1s to start at -0.3 sec and changed the gain from 2 to 3. Moved the proportional gain step down to -0.2 sec. The motivation for the OH1 and OH2 changes was to reduce the current rise since it seems to be increasing too rapidly. The EF1 changes are to make us less dependent on random changes in the EF1 power supply.
Dec 16 1994 01:23:31:550PM	941216013	Joseph Snipes	Shot 13 Good plasma! Apparently with some luck. There are still differences between EF1U and EF1L that we are trying to sort out. For shot 14 Horne lowered the pre-programmed EF1U and L voltages before 0.1 sec to reduce the demand.
Dec 16 1994 01:39:47:730PM	941216014	Joseph Snipes	Shot 14 Plasma died early at about 0.4 sec. While there are problems with the EF1L supply, it seems that the early drop in the proportional gain may also be a problem.
Dec 16 1994 01:46:13:640PM	941216015	Joseph Snipes	Shot 15 Keeping the proportional gain up until -0.02 sec instead of stepping it down at -0.3 sec. Decent plasma. Disrupted at 1.35 sec.
Dec 16 1994 02:06:40:650PM	941216016	Joseph Snipes	Shot 16 Changed EF1U and L integral gain turn on from -0.3 sec to -0.1 sec to reduce the amount of time of integration to reduce the accumulated error. Good shot! Disrupted late again.
Dec 16 1994 02:19:24:090PM	941216017	Joseph Snipes	Shot 17 Dropped density at 0.85 sec to try to avoid the late disruption-in-tail. Fizzle!
Dec 16 1994 02:48:27:510PM	941216018	Joseph Snipes	Shot 18 Lowered fill pressure to 1.4 x 10^-5 Torr. Decent plasma. Disrupted late.
Dec 16 1994 02:50:33:570PM	941216019	Joseph Snipes	Shot 19 Good shot! Disrupted late again. For shot 20, moved RCUR in by about 8 mm at 0.85 sec and throughout the rampdown. Also moved CLEARIN in by a small amount at the same time.
Dec 16 1994 03:22:44:720PM	941216020	Joseph Snipes	Shot 20 Good shot!
Dec 16 1994 03:24:31:580PM	941216021	Joseph Snipes	Shot 21 Good shot! For shot 22, reducing proportional gain on fast ZCUR wire 3 after 1.2 sec from 8 to 6 to attempt to get rid of the Z oscillations late in the hope that the plasma will be more stable in the rampdown to avoid the late disruption.
Dec 16 1994 03:45:13:190PM	941216022	Joseph Snipes	Shot 22 Good shot! For shot 23, raising the prefill to 1.5 x 10^-5 Torr to try to eliminate the hard x rays. Also moving RCUR out by 5 mm to improve RF coupling.
Dec 16 1994 04:05:02:480PM	941216023	Joseph Snipes	Shot 23 Good Shot!
Dec 16 1994 04:05:30:330PM	941216024	Joseph Snipes	Shot 24 Good Shot!
Dec 16 1994 05:31:57:170PM	941216024	Joseph Snipes	Shot 24 Good Shot!
Dec 16 1994 05:32:02:320PM	941216024	Joseph Snipes	Shot 24 Good Shot!
Dec 16 1994 05:35:53:040PM	941216024	Joseph Snipes	Overall, it was a reasonably successful run despite problems with the EF1L power supply that led to a large number of fizzles and some later control problems. At the end of the day, the RF coupling was successful and that was the purpose of the run. Because of yesterday's opening, the run started late and because of Navratil's seminar, the run ended early. Still, there were 24 shots, 17 plasmas, and 7 fizzles.
Dec 16 1994 05:47:24:220PM	941216024	Joseph Snipes	Problems with EF1 at breakdown led us to begin to use integral control for the EF1s. At first, we integrated from -0.3 sec to 0 with a gain of 1. This turned out to be too much. It was backed off toward the end of the run to start at -0.1 sec and then worked fine. We also tried to eliminate the late disruptions in the current rampdown by decreasing the proportional gain on the fast ZCUR (wire 3). It does not seem to have had much effect, since the Z oscillation around 1.2 sec was still there on the last shot, though it seems to come and go. Also, the cross-over of the OH1 supply at about 0.3 to 0.35 sec leads to some jumps in the loop voltage and changes in the radiation signals (bolometer, H alpha, Z meter) indicating that some impurities may be coming into the plasma at that time. This should be looked into and corrected.

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	09:13:11:660AM	Plasma	Ok	fizzel
2	09:26:16:250AM	Plasma	Ok	fizzle
3	09:43:39:230AM	Plasma	Ok	0.8MA disruption
4	10:06:08:850AM	Plasma	Ok	fizzle
5	10:18:15:250AM	Plasma	Ok	comm fault ef1, oh1oh2
6	10:33:29:830AM	Plasma	Ok	no faults
7	10:54:43:610AM	Plasma	Ok	no faults
8	11:34:53:870AM	Plasma	Ok	no faults
9	11:47:36:280AM	Plasma	Bad	ef1l comm fault
10	12:05:58:680PM	Plasma	Ok	no faults
11	12:18:06:450PM	Plasma	Ok	no faults
12	12:38:32:010PM	Plasma	Ok	no faults
13	01:07:21:600PM	Plasma	Ok	no faults
14	01:22:52:290PM	Plasma	Ok	no faults
15	01:40:25:280PM	Plasma	Ok	no faults
16	01:54:01:810PM	Plasma	Ok	no faults
17	02:10:54:800PM	Plasma	Ok	no faults
18	02:21:43:930PM	Plasma	Ok	no faults
19	02:38:20:480PM	Plasma	Ok	no faults
20	02:55:42:260PM	Plasma	Bad	ef1l comm fault
21	03:12:54:110PM	Plasma	Ok	no faults
22	03:29:54:240PM	Plasma	Ok	no faults
23	03:46:17:400PM	Plasma	Ok	no faults
24	04:03:07:070PM	Plasma	Ok	no faults