| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Steve Wukitch |
| Physics operator(s): | Ian Hutchinson |
| Engineering operator(s): | Sam Pierson,Ed Fitzgerald |
| Engineering Operator Run Comment |
| ICRF Testing & Conditioning EO Pierson, SL Wukitch, PO |
| Session Leader Plans |
| Entered: Jul 21 2009 04:52:33:710PM |
| Author: Steve Wukitch |
| 1. Using standard discharge developed Friday (1090717029 is a good
example except nl04 needs to be increased from 0.6 to 0.7), we will begin J antenna operation. We will run J separate from D and E antennas and begin with low power pulses. After evaluating the state of J antenna from an operational standpoint, we will seek to increase the power to 2 MW. 2. Discharge target is 1 MA, 5.4 T with moderate shaping and 1 cm outer gap. If time permits we will change plasma current and density to condition the antenna and other surfaces. |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 22 2009 10:47:42:150PM |
| Author: Steve Wukitch |
| We managed to trouble shoot the J antenna transmitter low level RF system but did not have sufficient opportunity to test J antenna into plasma. There were a limited number of plasmas due to EF4L fault among other problems. The EF4L fault was caused by short in the bus outside the cryostat, on the machine side of the rogowskis. Two bolts of the wrong length and inserted in the wrong direction acted as a spark gap. Once fixed, main gas puff was working incorrectly and a work around was implemented and 007 was a reasonable target. One of the transmitters, FMIT#4, however had unusually low demand. It was rectified by power cycling the board and the transmitter worked fine into dummy load. There was no further discharges due to alternator vibration. |
| Physics Operator Summaries |
| Entered: Jul 22 2009 04:54:27:813PM |
| Author: Ian Hutchinson |
| Overview
__________ The first shot had no main gas and disrupted because of a fault on EF4. This was a serious overcurrent eventually traced to a short in the warm bus on the machine side of the rogowskis. After reassembly, gas was still in bad shape and the first and only plasma with a main gas puff was shot 7 with direct connection to the valve, chopping removed. We shut down early because of alternator vibration. In all mostly an engineering bug fixing day. Only 3 plasmas. Essentially no RF conditioning accomplished. Scorecard __________ Shot,Duration(s),Ipmax(MA),Result Shot,Duration(s),Ipmax,Result | 01 0.739 1.017 Plasma | 02 0.000 0.006 Dud | | 03 0.000 0.002 Dud | 04 0.000 0.002 Dud | | 05 1.965 1.014 Plasma | 06 0.000 0.003 Dud | | 07 1.966 1.014 Plasma Date 1090722: 7 shots. 3 plasmas. 0 fizzles. 4 duds. 0 System Error. All duds were deliberate gas or power supply tests. |
| Session Leader Comments | |||
| Jul 22 2009 09:25:17:967AM | 1090722001 | Steve Wukitch | early disruption - no RF
power supply question - big spike on EF4_L |
| Jul 22 2009 09:32:18:643AM | 1090722001 | Steve Wukitch | holding: checking EF4_L - it is going to take some time |
| Jul 22 2009 12:29:56:313PM | 1090722001 | Steve Wukitch | still holding |
| Jul 22 2009 02:14:43:687PM | 1090722001 | Steve Wukitch | still holding
found arc in the EF4L bus where two bolts were too close estimated restart time is ~2:30 |
| Physics Operator Comments | |||
| Jul 22 2009 09:06:03:980AM | Ian Hutchinson | Load from 1090717029
Raise nl04 to 0.7e20. Was 0.5 (not .6 as per SL Plan) This shot limits on the inner divertor corner till 200ms. I think that is a bad idea. But I'll leave EF1 crowbar at .2s for first shot. Lower the zxu gain step at .3s to 4 (from 6). Load. | |
| Jul 22 2009 10:26:58:750AM | 1090722001 | Ian Hutchinson | Disrupts at 0.75s. EF4L has a big current spike on it at .63 then crowbars.
EF4L shows every evidence of a short circuit on the machine side of the rogowskis. At .631s the bus voltage drops to about 50V and simultaneously the rapid current ramp in EF4L begins. It reaches 15kA in EF4L rogowski at .6375, about 6ms later. The current rises in approximately 2 PS-phases. At .635s, probably in the second phase, the Reverse Inhibit goes positive. At .642s the PS detects a shoot-through. The bus voltage drops to zero at 0.664s, when the EF4L current has returned to the same level as EF4U. It looks like a short across the terminals of EF4L. Stop to do engineering diagnosis. |
| Jul 22 2009 01:09:54:657PM | 1090722001 | Ian Hutchinson | Hipot of EF4L shows good resistance to ground.
Ring out of EF4L shows the coil to be reproducibly good at 3kV charge. [After one or two somewhat strange traces in the early tests.] |
| Jul 22 2009 02:17:07:047PM | 1090722001 | Ian Hutchinson | After further discussion and inspection, an arc has been found between the
bus connectors above the cold bus. The bolts are to be replaced and insulation installed. |
| Jul 22 2009 02:59:40:110PM | 1090722002 | Ian Hutchinson | EF4 test under PLC control. Plus gas enabled to test the puff problems.
EF4 looks fine. The gas came on full blast. Draw a ramp up and a ramp down in the PG3. Load. |
| Jul 22 2009 03:26:47:670PM | 1090722003 | Ian Hutchinson | Gas is shown to be broken at the chopper board.
Set up to connect input to output. Load seg 1 from shot 1. Let preprogrammed puff be 100V till time 50ms. Then hope that the feedback can do it from there on. Load. Change mind. Use a board from before load the ramp again and do a gas test. |
| Jul 22 2009 03:41:08:250PM | 1090722004 | Ian Hutchinson | Gas test. It was decided after the fact that this should not work because
the pin out was different. It did not give a puff. Replace with a board with input connected to output. Put back the 100V till 50ms puff trace. Load. |
| Jul 22 2009 04:03:36:297PM | 1090722005 | Ian Hutchinson | Plasma to rampdown. No segment 2 puff.
Install a 100V puff in Seg 2, PG4 .02 till .1s ramping down to low at .5s Install 40psi in B-Side-Upper. Install a 20ms 100V pulse on PG2 at 1s in segment 2. Load. |
| Jul 22 2009 04:12:28:343PM | 1090722006 | Ian Hutchinson | Gas test. Got gas from the B-main with the chopper board changed to be a wire.
Set the PG3 puff to be short. Load. |
| Jul 22 2009 04:47:07:670PM | 1090722007 | Ian Hutchinson | Plasma to rampdown. Got gas but rather oscillatory.
Move plasma in 3mm at .3s. Reduce gas proportional gain to 3 from 8. Keep derivative gain on through shot. Draw a faster current ramp in the first .1s as we are getting. Load. Never ran the next shot because of alternator vibration. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:05:30:903AM | Plasma | Bad | EF4 Type 1 Fault |
| 2 | 02:50:30:483PM | Test | Ok | EF4 Reverse Test |
| 3 | 03:03:34:500PM | Test | Bad | Gas Test |
| 4 | 03:27:16:170PM | Test | Ok | Gas Test |
| 5 | 03:37:27:547PM | Plasma | Ok | |
| 6 | 03:58:53:860PM | Plasma | Ok | No Power, Gas Puff Only |
| 7 | 04:11:29:110PM | Plasma | Ok | |
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