| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Steve Wolfe |
| Physics operator(s): | Steve Fairfax |
| Engineering operator(s): | Joe Daigle,Vinny Bertolino |
| Engineering Operator Run Comment |
| fix power supplies |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:09:727PM |
| Author: To Be Determined |
| Session leader's report on run of 940503 SL: Wolfe PO: Fairfax EO: Bertolino, Daigle Miniproposal #041 - CMOD Startup The plan was to first verify that the problem with OH2L not following its demand signal was fixed, then proceed to get a null and tune it upo to get plasma. As for the past several runs, the ultimate model was 931020003, with all the predictors modified to account for the dead F17 loop, and with the current ramp flattopped at 400kA. The good news is that the OH2L supply does indeed seem to be fixed. The power supply seemed to be following its demand signal well, except that the maximum voltage is still less than the supply rating. The bad news is, although we got fairly reliable breakdowns, we did not get the current to take off. We got an acceptable null on shot#2 (#1 had a fault early), and got a breakdown at 11msec. Tuning of Br got the breakdown earlier (8msec) on shot #3. The null looked fair. The next few shots were screwed up by a bad flux loop signal from F25. We actually prepared a shot with all predictors having F25 weight set to zero and adding half the F25 weight to the weights of F24A and F26. However, Granetz found a possible cause for the problem (a stray strand of wire at the integrator input) and so we took shot #6 without loading the hoked up predictors, and this worked. (The hokey shot was saved in [Fairfax.mds]PCS940503006.*;) Subsequent tuning seemed to favor a more positive Bz (30amps on EF4). The breakdown moved as early as 5.4msec, but did not take off. Dropping the pressure as low as 1.0e-5 Torr seemed to improve the burnout, but still did not give a current takeoff. We also tried (shot 12 and thereafter) putting the offset on RCUR predictor to 10000 (the value it used to have); this seemed to make the evolution of the fields better to my eye, but the plasma got somewhat shorter. We also had one more flux loop problem, on F23 on shot 13. F25 was still somewhat suspect. I think we don't yet have the post-null evolution tuned up right. Also, it appears possible that lowering th pressure further could be helpful. The ratiomatic is reading higher than the torus gage; it is possible the torus gage is reading too low compared to last year. The problems with intermittant flux loop signals are troubling. After the run, Bob interchanged the wiring on F25 and F24 (F24 is not used, F24A is) in case the problem was in the integrator or connectors. F25 is known to be shorted to the vessel, but this problem may be external. F23 is not shorted, and the evidence points to a flakey integrator. The power supplies behaved well. One shot (#1) was lost to an early fault indication, apparently spurious. There were a couple more problems after the plasma which did not impact the run. Despite our good intentions, the run did not start until 10:00. The alternator took longer than expected and the machine was not cold until 9:40. Apparently Monday's "cooldown" was done in bakeout mode, which did not do anything to the structure temperature. Scorecard: Duds 5 Fizzles 11 Good 0 ---------- Total 16 |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:36:51:003PM |
| Author: To Be Determined |
| Physics Operator Summary May 5, 1994 Miniproposal 41 Session Leader: Wolfe Physics Operator: Fairfax Eng. Operator: Bertolino State Operator: Pierson Cryo Operator: Sorci Power Systems: Paranay Delayed 1 hour by alternator. Procedure error in warming yesterday. Start with 940429008 loaded into hybrid Shot 1 - OH2U commutation failure Early Shot 2 Flash. Breakdown at 11 msec. Changed Br offset by -1 mT Delayed 15 minutes by warm structure; procedure error in cooling yesterday. Shot 3 Flash. Breakdown at 8 msec. Br is better; responded exactly as programmed. Increased EF4 current by 30 amps (about 1 mT) from -1012.5 to -982.5 A Shot 4 No flash. Br and Bz off. Not clear what is wrong. reload shot 3 and try again Shot 5 No flash. OH2 currents quite different from shot 3, but supplies appear to be working OK. Check of flux loops shows 25 is reading only about 75% of it's value on shot 3. Steve Wolfe tried to fake the F25 signal as the average of F24a and F26 signals. Bob Granetz and I went into the cell and checked the F25 resistance. F25 is shorted to the machine. We found a small wire touching the connector body on the cable leading to the integrator input. Next shot will use the matrix from shot 3; Steve Wolfe's patches are finished but not yet loaded. 20 minutes delay while recooling coils due to warm structure. Shot 6 Flash. Flux 25 is good. Saved Steve's patch in [fairfax.hybrid] as shot 940503006 (even though it's not.) Changed EF4 current precharge from -1012.5 to -952.5 amps (about 2 mT) NOTE: "Compose Character" is not the ALT key on PHYSOP as it was on XHARPO. The "Alt Function" key is ALT. Shot 7 No flash. Bz slightly positive. Changed EF4 current precharge from -952.5 amps to -982.5 (about 1 mT) Shot 8 Flash. Breakdown at 6.5 msec; better. Set Br another mT lower. Offset now -2 mT. Shot 9 Flash. Breakdown at 5.5 msec. Changed pulse gas program back to -10 msec from -50 msec. Shot 10 Flash. Basically same breakdown. Changed fill pressure from 1.4 to 1.2e-5 Shot 11 Flash. Added +10000 offset to RCUR Shot 12 Flash. Lowered gas fill to 1.1e-5 Shot 13 no flash. Flux loop 23 now screwed up. Horne doesn't have to shuts up yet. No changes for next shot. Shot 14 Flash. Flux loops seem OK. Artur says diverter guage shows gas puff at 4 msec; he's wrong.(it's 40) Delay pulsed gas by another 10 msec anyway. Shot 15 Flash. Marginally worse breakdown. Copied OH2U voltage prog to OH2L (there was a 20 v difference after commutation.) Dropped fill pressure to 1.0e-5. Shot 16 Flash. Deliberate crowbar of TF for Gwinn. |
| Session Leader Comments | |||
| May 3 1994 08:40:23:010AM | Steve Wolfe | Run 940503
Miniproposal #041 : Startup C-MOD SL: Wolfe PO: Fairfax EO: Bertolino P before ECDC = 5.8e-8 Discharge cleaned in D2 for 3.5 hours, starting at 04:30. Hybrid program:start from 940429008, before last Friday's "adjustments", which were basically trying to compensate for a problem in OH2L. Plan: Get plasma. If first try indicates OH2L problem is still there, go to PLan B -- fix the supply first, then get plasma. Once breakdown and current rise are established, adjust radial position inward to clear limiter. Then extend pulse length. | |
| May 3 1994 09:32:46:610AM | Steve Wolfe | We will be delayed until alternator and cooling come up. All coils are
showing green except TF. The TF vertical arms aer lagging. The cylinder is quite warm; yesterday's cooling did nothing noticeable to structure or dome temperatures. The cooling was done in BAKEOUT mode which just keeps the coils safe, does not really cool. | |
| May 3 1994 10:10:56:960AM | 940503001 | Steve Wolfe | First try for plasma. P=1.4e-5T, program loaded from 9404290008
OH2U faulted at -.82 sec. |
| May 3 1994 10:40:10:830AM | 940503002 | Steve Wolfe | Got a flash.
OH2L seems ok - follows its demand. Breakdown at 11msec. Br = 1mT , Bz= -5mT For next shot change Br offset to -.001mT, don't worry about Bz for now. |
| May 3 1994 11:13:21:060AM | 940503003 | Steve Wolfe | Got a flash.
PF breaker pulled out late. Breakdown at 8.1msec Null doesn't look too horrible. Some Br after breakdown, and Bz is -5mT. For next shot, make EF4 30A more positive. |
| May 3 1994 11:41:54:410AM | 940503004 | Steve Wolfe | No flash.
Big radial field, where the hell did that come from? There is a 300 amp oscillation on the OH2's. Also the OH2L is now more negative than OH2U by 2000A; it was the other way around on shots 2&3! For next shot, reload shot 3 |
| May 3 1994 11:49:11:800AM | 940503005 | Steve Wolfe | No flash.
Big radial field, where the hell did that come from? Similar to 4 |
| May 3 1994 11:59:18:540AM | 940503005 | Steve Wolfe | No flash.
Big radial field, where the hell did that come from? Similar to 4 Flux loop 25 (F25) is reading low! It's died since shot 3. It's reading 1.07 instead of 1.27 Can try to fix in software, Bob should look at it after the run. |
| May 3 1994 01:07:45:010PM | 940503005 | Steve Wolfe | Quick and dirty fixup for F25 dead in predictors. Replace F25 by
0.5*(F24A+F26). Do thins manually in the CUSTOM predictors as follows: RCUR F25=-21998.9, F24A=-8859.39->-19858.8 F26=-35558.6 -> -46558 ZCUR F25=-38522, F24A= -38949.3 -> -58225.3 F26= -4044.16 -> -23320.2 ZXL F25=-42468.5 F24A= -26993.3 -> -48167.6 F26 = -18424.9 -> -39658.25 RXL F25=-53095.9 F24A= -39502.0 -> -66049.95 F26 = -50611.2 -> -77158.95 Clearin F25=18042.0 F24A= 48204.0 -> 57225.0 F26= -68957.7 -> -59936.7 BR_0 F25=9.359961e-2 F24A= 3.830151e-2 -> 8.51013e-2 F26= .104361 -> .151161 Needed to change factor on BR_0 from 40. to 25. Also changed RXL factor from 7e-5 to 5e-5. Set up these changes, but don't load for next shot. Granetz found a possible bad connection, so we'll see if it works now. |
| May 3 1994 01:32:02:200PM | 940503006 | Steve Wolfe | Got a flash back. Did not use the previous hacks, Bob may have fixed
it. Flux loop looks ok, maybe. Changes saved in [FAIRFAX.HYBRID] PCS_940503006* Breakdown at 7.8msec For next shot, try again to make EF4 more positive by 60Amps. |
| May 3 1994 02:03:17:980PM | 940503007 | Steve Wolfe | No flash
MFLUX says no null. Vacuum says Bz=0 from 0 to 6 msec Try setting EF4 more negative by 30 Amps. There may still be a problem on F25. It looks like it didn't come back to zero this time. |
| May 3 1994 02:17:13:050PM | 940503008 | Steve Wolfe | Got the flash back.
Breakdown at 6msec MFLUX looks like it's having a positive BR at 10-15 msec Try changing Br_0 offset from -.001 to -0.002 T |
| May 3 1994 02:37:59:960PM | 940503009 | Steve Wolfe | Flash is back
Breakdown at 5.4msec Delay pulse gas 3 back to -10msec (from where Joe had moved it last week) |
| May 3 1994 03:01:30:180PM | 940503010 | Steve Wolfe | Flash is back
Breakdown at 5.4msec Light lasts longer, but no more current. For next shot change P from 1.4e-5 to 1.2e-5 |
| May 3 1994 03:15:30:980PM | 940503011 | Steve Wolfe | Flash is back
Breakdown at 5.7msec Light lasts longer, but no more current. No obvious change. For next shot change offset on RCUR from 0. to 10000. |
| May 3 1994 03:22:17:570PM | 940503011 | Steve Wolfe | Flash is back
Breakdown at 5.7msec Light lasts longer, but no more current. No obvious change. For next shot change offset on RCUR from 0. to 10000. |
| May 3 1994 03:43:40:980PM | 940503012 | Steve Wolfe | Flash is different. Shorter, and maybe a msec or two later.
Lower fill to 1.1e-5 |
| May 3 1994 03:50:09:270PM | 940503012 | Steve Wolfe | Flash is different. Shorter, and maybe a msec or two later.
Lower fill to 1.1e-5 |
| May 3 1994 03:58:35:790PM | 940503013 | Steve Wolfe | Lost the breakdown.
Integrator problem on flux loop 23 ???? Maybe something different on 25 Try again. |
| May 3 1994 04:15:21:820PM | 940503014 | Steve Wolfe | Got the breakdown back.
Try delaying the gas another 10msec (to 0.) |
| May 3 1994 04:17:22:850PM | 940503014 | Steve Wolfe | Got the breakdown back.
Try delaying the gas another 10msec (to 0.) |
| May 3 1994 04:32:01:940PM | 940503015 | Steve Wolfe | Try delaying the gas another 10msec (to 0.)
No obvious difference. Try removing the differnece in the OH2 V programming (copy upper into lower.) |
| May 3 1994 04:33:53:000PM | 940503015 | Steve Wolfe | Try delaying the gas another 10msec (to 0.)
No obvious difference. Try removing the differnece in the OH2 V programming (copy upper into lower.) Also lower P to 1.0e-5 |
| May 3 1994 04:56:46:760PM | 940503016 | Steve Wolfe | Burnout is better, but still no takeoff.
This was the last shot of the day. Intentional E-stop hit to give Gwinn some data on alternator shaft vibration. |
| Physics Operator Comments |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 10:05:49:850AM | Plasma | Bad | oh2u comm fault |
| 2 | 10:29:21:070AM | Plasma | Ok | no faults |
| 3 | 10:57:11:920AM | Plasma | Ok | oh2u comm fault after shot |
| 4 | 11:16:33:160AM | Plasma | Ok | no faults |
| 5 | 11:43:41:590AM | Plasma | Ok | no faults |
| 6 | 01:19:58:050PM | Plasma | Ok | no faults |
| 7 | 01:53:30:520PM | Plasma | Ok | no faults |
| 8 | 02:08:01:390PM | Plasma | Ok | no faults |
| 9 | 02:28:37:560PM | Plasma | Ok | no faults |
| 10 | 02:49:59:970PM | Plasma | Ok | no faults |
| 11 | 03:09:15:160PM | Plasma | Ok | no faults |
| 12 | 03:27:55:440PM | Plasma | Ok | no faults |
| 13 | 03:48:00:740PM | Plasma | Ok | no faults |
| 14 | 04:07:01:970PM | Plasma | Ok | no faults |
| 15 | 04:25:19:000PM | Plasma | Ok | no faults |
| 16 | 04:45:28:170PM | Plasma | Ok | e-stop at end of the shot to check alernator rpm data |