| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Steve Wolfe |
| Physics operator(s): | Steve Horne |
| Engineering operator(s): | Joe Daigle,Vinny Bertolino |
| Engineering Operator Run Comment |
| day 2 plasma start up |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:13:943PM |
| Author: To Be Determined |
| Session Leader Summary for 951027 MP#120 C-MOD restart 1995 SL: Wolfe/Horne PO: Horne/Wolfe EO: Bertolino/Daigle The plan for today's run was to get the power supplies fixed and then proceed to make plasmas. After that we were supposed to tune up the plasma and a lot of other ambitious things. As it turned out, we got plasma, left some supplies in uncertain condition, and found a possible problem in the Hybrid. Progress (toward standing by) was definitely made. Obviously, MP#120 will need at least another day next Tuesday. We started by trying to get the problem with the OH2's on inversion sorted out. This was a very puzzling situation, as inverting from negative current in either or both OH2 supplies caused fault indications in the bypass cabinet. This did not show up last week, apparently because tests then were only done up to 10kA and the problem didn't manifest until around 20kA. The first 8 shots were spent trying to isolate and diagnose this problem, without noticeable success. On shot 9, having ascertained that it was unlikely to endanger anything, we set up for a full plasma attempt, on the theory that a flash would either happen or not before the inversion problem occurred. There was also speculation that the alternator loading might prevent the noise or whatever from reaching the level to cause the fault. This turned out to work, in the sense that the fault did not come up again all day. Note that it isn't fixed, just hiding. Shot 9 had two problems. The TMX supplies (EF2's, chopper bias) did not come on because their contactor opened on an earlier access fault and was not reclosed. More significantly, the EF4 had a shoot-through problem near crossover and blew some more fuses. It was also noted that the EF4 is apparently not listening to the fizzle detector. We decided to proceed by disabling the reverse supply on EF4 after replacing the fuses. Gwinn and company spent much of the remainder of the run figuring out a better crossover circuit. Shot 10 was the second plasma attempt, the first with no power system problems. Amazingly, we got a 400kA , 150 msec plasma! The density reached 5e19 on NL04. We probably should have stopped at one-for-one, but we didn't. It was noted that the demand signal to the chopper was wrong, consisting of just the wavegen output and no PID output. This seems to have been the case for the past week, at least. Shot 11& 12 were a straight repeats, and fizzled. On shot 13, we tried moving the fast ZCUR from wire 3 to wire 11, to try to get the chopper demand back. The shot was another fizzle, and the M-chopper demand was unchanged. This seemed to isolate the hybrid problem to a DAC card. On shot 14, we dropped the pressure from 1.8 to 1.5e-5 and turned off the chopper. We got back essentially the same 400kA shot, which again died vertically at 150msec. At this point Ian convinced me we shouldn't continue without trying to get the chopper working. Horne changed out the suspect DAC card on the hybrid. Data system only tests were then carried out (#15, 16) with the result that the same bad signal appeared on the chopper demand line. At this point, we punted. After the run, Horne checked out the hybrid hardware and found it to be functioning correctly. As I write this, he is poking at the software and alternating between cursing and exclamations of Eureka. He seems to have found a bug in his new software. Plasma attempts: 6 Plasmas: 2 Fizzles: 3 Duds: 1 (TMX supplies off) |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:36:55:113PM |
| Author: To Be Determined |
| Physop log, 951027 Horne See Wolfe's SL log for details on power supply faults of various sorts Good news is we Made A Plasma on first legitimate attempt (shot 10). (Shot 9 was an attempt, but some power supplies didn't fire.) Shot 14 was also a plasma. I spent my time tracking down a peculiar problem with the hybrid output to the chopper. Apparently there was no feedback; only the preprogramming appeared at the output of the hybrid. After some painful contortions, including changing out the DAC card which was implicated, we punted the run. After some more hardware testing the problem was diagnosed as software; the wrong gains were being loaded. This tracked back to code I rewrote to support the asynchronous segments; in the code which prepares the rt-node switch tables, where I should have been counting M matrices, I counted the A matrices (again). (cut, paste, forget to edit.) Thus we got only the first 5 M matrices loaded into the DACs (since there are 5 a-matrices) instead of the correct value (10). This has been fixed, and a test shot shows (more) correct behavior. I tender my most abject apologies for the screwup. A point -- we shouldn't forget that the controllers weren't what we expected today. If we have difficulties making a plasma next run, we might look back to today's run and reconstruct (I can do that) the controllers we really were running. PCS note -- we've added a couple of buttons to each segment which will recalculate all the predictors. We're also testing built-in help on pcs -- it only works for these two new buttons so far, but we'll probably add it in some other places. Steve |
| Session Leader Comments | |||
| Oct 27 1995 08:24:03:890AM | Steve Wolfe | MP 120: Restart
SL: wolfe PO: horne EO: Bertolino/Daigle Plan- See yesterday's plan. We'll start with OH2 non-commutation, double swing test. See if we can determine what was wrong on last shot yesterday. Tom reports that the highway errors got "fixed" by power cycling a different crate. Highway was totally gronked this morning, but may be ok now. | |
| Oct 27 1995 09:07:57:520AM | 951027001 | Steve Wolfe | OH2 non-commutation under hybrid control, like yesterday #26 but not
commutate. Joe says "same problem" Hybrid asked for more current after t=0. Traced down to RCUR wire. This would have been different on #26, as on that one OH1 was also on. Engineers are out looking at power supply. I hope they aren't chasing ghosts. |
| Oct 27 1995 10:05:03:540AM | 951027002 | Steve Wolfe | 951027002
PLC test OH2U only Still getting a bypass fault at inversion. |
| Oct 27 1995 10:23:25:610AM | 951027003 | Steve Wolfe | 951027003
PLC OH2U test opposite direction current. That seems ok |
| Oct 27 1995 10:28:09:340AM | 951027003 | Steve Wolfe | 951027003
About half of the full flux loops didn't get data on shot 3!*&^#$%^ It isn't fixed. |
| Oct 27 1995 10:56:53:330AM | 951027004 | Steve Wolfe | 951027004
OH2L PLC test, reverse current. Joe Bosco has taken the PROBE crate off the highway. We'll see if that helps. OH2L crowbarred around -.5sec Magnetics looks ok this time. |
| Oct 27 1995 11:23:02:350AM | 951027005 | Steve Wolfe | 951027005
Repeat of shot 4. They haven't a clue. OK (no faults) that time. Big glitch on the current at -.27sec Magnetics look ok |
| Oct 27 1995 12:04:12:830PM | 951027006 | Steve Wolfe | 951027006
OH2L negative current plc test breaker pulled. Fault indicator in bypass |
| Oct 27 1995 12:13:41:890PM | 951027007 | Steve Wolfe | 951027007
OH1, OH2U&L PLC test. 10Ka It worked. |
| Oct 27 1995 12:28:12:440PM | 951027008 | Steve Wolfe | 951027008
OH1, OH2U&L PLC test. 15kA on OH1, 20kA on OH2's Breaker pulled, got a crowbar. OH2U. |
| Oct 27 1995 12:52:56:110PM | 951027009 | Steve Wolfe | 951027009
While looking for ghosts, go ahead and turn on everything else, and try for plasma. No flash. No EF2's. No chopper either. EF4 had a problem at crossover. No fault on the OH2's!!! TMX problem due to access breach after contactors closed, not reclosed. |
| Oct 27 1995 02:04:38:870PM | 951027010 | Steve Wolfe | 951027010
Try again with TMX supplies on. Disable the reverse EF4 supply. Got a plasma. No faults. got to 400kA in 150msec. then disrupted. |
| Oct 27 1995 02:42:52:610PM | 951027011 | Steve Wolfe | 951027011
The chopper demand was not right on the last shot. The current rounded over early, probably resistive. Turn on the analysis tree this time. Repeat. No flash. There is an h-alpha signal, the TV filter must be in again. fizzle. |
| Oct 27 1995 02:53:25:850PM | 951027012 | Steve Wolfe | 951027012
Repeat. fizzle. 20kA |
| Oct 27 1995 03:06:02:740PM | 951027013 | Steve Wolfe | 951027013
Move fast zcur to wire 11. Chopper wasn't getting correct signal. Another fizzle. about 20ka again Chopper demand looks the same. It looks like only the Vout is coming through. |
| Oct 27 1995 03:32:14:360PM | 951027014 | Steve Wolfe | 951027014
Drop fill to 1.5e-5 Turn off the chopper. Plasma, got a PF breaker pull. 400kA. had some hesitation, but made it through. OH2's look funny, as if driving the wrong way. |
| Oct 27 1995 03:50:02:350PM | 951027015 | Steve Wolfe | 951027015
Changed out a DAC card on the Hybrid. Data system only test. Error on INIT in Hybrid = A-matrix private bus not responding. Chopper M-out is the same as before. |
| Oct 27 1995 06:01:26:750PM | 951027016 | Steve Wolfe | 951027016
Try the data system test again. No change in chopper demand. Punt, and work it out afterward. |
| Physics Operator Comments |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:46:17:760AM | Test | Ok | |
| 2 | 09:58:36:050AM | Test | Ok | |
| 3 | 10:21:04:920AM | Test | Ok | |
| 4 | 10:53:02:790AM | Test | Ok | |
| 5 | 11:19:15:360AM | Test | Ok | |
| 6 | 11:49:46:550AM | Test | Ok | |
| 7 | 12:11:46:760PM | Test | Ok | |
| 8 | 12:16:17:950PM | Test | Ok | |
| 9 | 12:45:22:170PM | Plasma | Bad | no tmx's |
| 10 | 01:55:10:310PM | Plasma | Ok | |
| 11 | 02:35:04:360PM | Plasma | Ok | |
| 12 | 02:43:25:460PM | Plasma | Ok | |
| 13 | 02:56:23:490PM | Plasma | Ok | |
| 14 | 03:10:01:930PM | Plasma | Ok | |
| 15 | 03:36:29:720PM | Test | Ok | |
| 16 | 03:51:57:780PM | Test | Ok | |