| Miniproposals | ||||||||||
|
| Operators | |
| Session leader(s): | Steve Wolfe |
| Physics operator(s): | Ian Hutchinson |
| Engineering operator(s): | Vinny Bertolino,Joe Daigle |
| Engineering Operator Run Comment |
| 120 Startup |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:13:960PM |
| Author: To Be Determined |
| Session Leader's Summary for 951114 MP#120 Startup 95 SL: wolfe PO: Hutch EO: Daigle/Bertolino Goal was to finish up the startup MP: Raise current to nominal levels (1MA) Try again on pulse gas startup Establish 800kA fiducial shot Tune up of EF4 dead-time The linear gas valve driver has been installed on A-side. EF4 is on the fizzle detector Started from a reload of 951103015, with changes to the pulse gas waveforms. Although the goals were not fully met, enough was accomplished to declare this MP complete. The remaining pieces will hopefully be dealt with in the other runs this week. Briefly, the current was only raised to 800kA, not 1MA. Shot 95111431 seems to be a reasonable candidate for an 800kA fiducial shot. The pulse gas startup, using the B-top valve, works, although the bugs aren't all out of it yet. The pressure does seem to be reproducible, but the way we were using it, with the pressure still rising sharply at t=0, may not be ideal. No work was done on the EF4 deadtime. The pulse gas startup was accomplished by a single short pulse around -0.1sec on B-top (Pulse_gas_4), which had a plenum pressure of 20psi. The remainder of the gas was supplied by "a-side" (actually located on k-side) which had Willy's duty cycle driver on it, and was also filled to 20psi. The pressure at t=0 was varied, by varying the length of the PG4 pulse, from around 8e-6 to 1.3e-5. No runaway discharges were produced, and most startups looked to me as if they were being overgassed. With no plasma, a pulse getting 1.3e-5 at t=0 (shot #5) ended up with 4e-5 at t=0.4 sec. The linear (duty-cycle) gas valve driver seemed to work pretty well, although there was no obvious advantage over the direct drive version. It appeared that we were not getting enough gas to push much higher than 1e20 without adding gas from another valve. Of course, using B-top would be straightforward since we are already using it for startup. For now, we decided to leave the duty-cycle driver in; it can be changed back quickly if desired. For a detailed blow-by-blow account of the run, see the Physics Operator's Summary and the SESSION_LEADER topic in the logbook. Briefly: Shot 1-6 Gas tests (shot 2 was Tuesday test as well) Shot 7-9 Fizzles Shot 10-18 600ka plasmas, and some fizzles Shot 19-22 800kA attempts, limited to <700kA by the EF3 problem described below; also some fizzles Shot 23-26 EF3 tests Shot 27-32 800kA shots (and fizzles) One major problem encountered today is that the EF3 current regulation was coming on at much too low a current. Apparently something has changed in this circuit since last June. The symptom was that the Ip and RCUR were not following their programs, and the EF3 demand voltage was rising and the output not responding. After it was determined this was indeed the problem, the EF3 PLC limit was raised to 20kA, which allowed the current to get to about 8kA! The engineers will try to have this fixed by tomorrow. In retrospect, this may explain why the RCUR position and current were bad (current <600ka) on 951031 when Granetz was running, and better (current >600kA) on 951103015 with the EF4 double swinging. The dreaded longitudinal parity errors surfaced again, this time on the CII and related signals. Joe Bosco got rid of them by once again jumpering out the Probe crates. We also had some other CAMAC problems, which Josh managed to repair and restore most of the lost data; these were apparently a "communication" problem(?). A minor problem was noted with the chopper. On a number of fizzles, the chopper IOC'd after one on pulse. This was "fixed" by a change in the gain programming as of shot 22. Note that the necessary change is in segment 2, as the problem occurs at 0.11 sec. There were also some problems with the alternator, resulting in a few shots on which the DC breaker opened during check state, requiring us to go back to recool and start again. This was apparently fixed by reducing the alternator voltage. Startup was very problematic all day, with the typical symptom being poor burnout and current hesitation. The CII signals were typically around 0.02 to 0.03 mw/cm2/ster. Some field tweaking was done, as well as a lot of tweaks to the initial gas. The last few shots actually had poorer current rises than earlier in the day, although breakdown was slightly earlier. We ended up with 11 plasmas and 11 fizzles, not counting gas and EF3 tests. |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:36:55:190PM |
| Author: To Be Determined |
| Physop Summary 951114 PO: Hutch, SL:Wolfe EO: Daigle, Bertolino. Continuation of Restart MP120 Summary _______ Established breakdown using the B-TOP valve for pulse fill. Shot 22 and following give OK breakdown, although carbon is high. Later shots used slightly lower fill. May be better. In general the machine behaved as rather dirty: high CII, tendency to alternate fizzles. Established density feedback control using the "linear" chopped controller on A-side valve. This works fine except there is a long delay to the first chop if the demand is low. Seems to be an offset of about 10%. Demonstrated a good 600kA plasma: Shot 18. Discovered an EF3 PLC limit problem in trying to go to higher plasma current. The actual EF3 limit is 0.43 times the programmed PLC limit. This is a linear calibration problem. Eventually finnessed by raising the set point to 20kA. Obtained a good 800kA plasma at 1.e20. Shape reasonable. Suggest shot 31 or 32 to start from.These could be fiducials but have the linear controller. We are running out of gas to get much higher density. Statistics __________ Shot,Duration(s),Ipmax(MA) Shot,Duration(s),Ipmax 1 0.000 0.003 2 0.000 0.010 3 0.000 0.003 4 0.000 0.003 5 0.000 0.003 6 0.000 0.003 7 0.000 0.016 8 0.000 0.016 9 0.000 0.019 10 0.612 0.691 11 0.000 0.019 12 0.000 0.021 13 1.420 0.652 14 0.000 0.021 15 1.400 0.647 16 0.000 0.024 17 1.285 0.652 18 1.529 0.652 19 0.983 0.707 20 0.000 0.021 21 0.000 0.022 22 0.933 0.720 23 0.000 0.008 24 0.000 0.008 25 0.000 0.008 26 0.000 0.008 27 0.000 0.019 28 1.485 0.833 29 0.000 0.022 30 1.477 0.833 31 1.472 0.833 32 1.224 0.833 Finished summary for 951114 Total of 32 shots. 32 shots. 11 plasmas. 9 fizzles. 12 duds. Fizzle = gt 17 lt 50kA. Details _______ Loaded 951103015 Pulse gas 4 B-Top. 100V, -.1 to -.092s. Pulse gas 3 A-side really on K-side. "Linear" chopping circuit controlled. Programmed. Both at 20 psi. No prefill. Alternator problem. Breaker pulled. 1 Gas Test B_Top opens all right and gives about 1e-5 at t=0. A-side voltage chops at about 100Hz but with a 30ms delay. 2 Power supplies also. B-Top gas puff looks reproducible. p(0)=10**(-5.06) Add 1 ms to B-puff. (-.100to -.091) Set a downward ramp on A-side 100V to 10V at 0.13s. 3 Gas test. p(0)=10**(-5.02). RGA looks like a big air puff. PG3 to (-.100 to -.089) PG4 Ramp 100(0) 26(30ms). 4 Gas p(0)=10**(-4.889)=1.3e-5 Still worried about the RGA Ramp responds sensibly and opens quickly. Disable A-side valve. 5 Gas RGA looks fine. p(0)=1.3e-5 quite reproducible. Shorten initial A-side puff ramp to 20ms. Lower level to 14%. Repurge A-side. 6 Gas p(0)=1.25e-5. A-side chops very spread out. ZXL gain to 30 s^-1. A-side to 20% at 25ms. 7 Fiz 20kA, BD at 6ms. Density very low. Camac error, no carbon. EF4 got -1055A EF4 to -1115 from -1100A. 8 Fiz Got EF4 -1071A. BD at .5ms Found that EF2U segment-1 controller is at .275 when the EF2L is at 0.37. So put EF2U to .37. Turn off probes to try to fix Camac. 9 Fiz 22kA, BD at 5ms. Fairly similar. Got CII trace, does not burn out. PG4 fill pulse to (-115 to -106ms ) hence later on the pulse. 10 Pla Disrupts at .6s. 100Hz vertical instability. ZXL gain back down to 4. 11 Fiz High Carbon level. PG4 to (-115, -107) one ms shorter. 12 Fiz BD at 4.5ms, 25kA. PG4 to (-115, -108) one ms shorter still. 13 Pla Went the duration. R_cur is at 65.5. This is too far in. XL is not in the right position. It is too far in. p(0)=9e-6, CII ~.01. R_cur to .665 (from .655). 14 Fiz CII=.022. BD at 5ms (later). EF4 to -1125A. 15 Pla Full length. RXL to -.005 from -.01, ZXL gain to 8 from 4. 16 Fiz Nearly went but signs of possible runaway. 17 Pla Ramped down only to 400kA. Vertical instability in down ramp. Data system errors, but fixed. ZXL gain to 1 at 1s, and drawn rising up, to avoid vertical problem. 18 Pla Nice ramp-down. Slight hesitation. Raise Ip to 800kA, NL to 1.e20. 19 Pla Disrupted at 1sec. Lots of Rcur and Ip problems staring at .36s. Plasma leans out. Never gets to current. Delay the Ip extra ramp till after .36s and make it more gentle. 20 Fiz PG4 to (-135,-127ms). (20 ms earlier). 21 Fiz PG4 to (-135,-127.5), 0.5 ms shorter. Also Chopper feedback lowered near its turn-on to try to avoid trips. 22 Pla Again banging hard on the outboard limiter during the attempt to raise the current. Tracked down the problem; EF3 is not following its demand. Power supply tests. Loaded from 951103013 PS test shot. Programmed EF3 7kA and a +-2000V oscillation of the V. 23 EF3 Test. Got the 2000V pp sawtooth bu the current never went over 6kA. PLC limit is at 15kA nominal, as per the day so far. Pushed demand up to 8kA, and kept EF3V up for longer in the initial upswing. There seems to be a factor of two difference between the buss voltage and the apparent PS voltage. 24 EF3 Still limited to 6kA. The PLC is not letting us go beyond. Lower PLC limit to 10kA. 25 EF3 Got even lower limit. About 4.3kA. This is essentially in constant ratio with the set limit. This is a hard limit. 26 EF3 PLC controlled to 0.42 of what was set hence establishing the calibration problem. Reload shot 22 and try again with nominal EF3 limit at 20 (=8.5kA). 27 Fiz CII high, .027, vertical field slightly higher. BD at 5.3ms. EF4 to -1125 (was -1115 but it should have been -1125, don't know why). 28 Pla Good shot. 7.5kA on EF3. Survived a big sharkfin at the end. Shakey breakdown. CII peaks at .023. Argon 20ms at .28s, RXL to -.002, NLo4 gain to 7 at .5s. 29 Fiz CII .025, 25kA. PG4 to (-135,0128) (0.5ms less). 30 Pla Tweaked the current and density traces to reach flat top a bit earlier. 31 Pla Still hesitates in current rise. Current and voltage got up to flat top earlier. Set OH1 voltage to 100V from 130V at 5ms. Increased Ar puff to 30ms. 32 Pla Disrupts at 1.2s at the start of the sharkfin. Hirex got a signal. |
| Session Leader Comments | |||
| Nov 14 1995 08:09:34:100AM | Steve Wolfe | MP#120 Startup
SL: wolfe PO: hutch EO: Daigle Goal is to finish up the startup MP. Remaining tasks are: Raise current to nominal levels (1MA) Try again on pulse gas startup Establish 800kA fiducial shot Tune up of EF4 dead-time The linear gas valve driver has been installed on A-side. EF4 is on the fizzle detector | |
| Nov 14 1995 09:03:57:920AM | 951114001 | Steve Wolfe | Shot 951114001
Load 951103105. Put pre-pulse PG4 (B-top) plenum at 20psi Normal pulse on PG3 (also at 20psi) with linear driver This will be a normal Tuesday test plus the gas puff. Alternator fault. Gas test only. B-top opened ok, got rising pressure at 9e-6 at zero, continues to rise A-side doesn't look right. |
| Nov 14 1995 09:12:20:390AM | 951114002 | Steve Wolfe | Shot 951114002
Tuesday test with gas. B-top looks reproducible. A-side still doesn't look right. TCI_analysis was turned off; I turned it on for next shot. |
| Nov 14 1995 09:25:06:880AM | 951114003 | Steve Wolfe | Shot 951114003
Put a ramp in PG3 programming. Make pre-pulse on PG4 1msec wider. Looks reasonable, but we are getting a burst of N2,O2, etc on RGA??? |
| Nov 14 1995 09:34:57:510AM | 951114004 | Steve Wolfe | Shot 951114004
One more gas puff test. INcreasing initial PG4 puff by 2msec Reduce PG3 puff. Get 1.3e-5 at t=0. |
| Nov 14 1995 09:40:23:000AM | 951114005 | Steve Wolfe | Shot 951114005
Test with a-side disabled. No RGA junk; Get 1.3e-5 at t=0, 4e-5 at t=.4 |
| Nov 14 1995 09:59:21:310AM | 951114006 | Steve Wolfe | Shot 951114006
Set the D2 regulator for 20psi, but it ended up higher. Never mind! Re-purge a-side plenum Ease off on A-side puff. One more gas test. 1.26e-5 at t=0 A-side has too low a pulse? |
| Nov 14 1995 10:15:58:750AM | 951114007 | Steve Wolfe | Shot 951114007
Try for plasma. A-side puff program back up to 20% Raise ZXL gain from 12/sec to 30/sec ECE gate valve open All power supplies ran. Fizzle. bd at 6msec No CII signal; store error on CAMAC. May be too much Bz |
| Nov 14 1995 10:35:28:080AM | 951114008 | Steve Wolfe | Shot 951114008
Make EF4 15A more negative. Fizzle. Getting 1.7uohm on OH2U coax No spectroscopy data this time. |
| Nov 14 1995 10:59:21:650AM | 951114009 | Steve Wolfe | Shot 951114009
EF2U controller gain was at .247 instead of .37??? Do we still have ghosts in the PCS setup from the gain changes? Set it back to .37 this time. Turn off the Probes nodes and jumper out the probes crate to try to get rid of LPE errors on the Spectr tree (CII signal) Another fizzle. Got the CII signal back; it definitely correlates with the probes crate. I think we need to back down on the initial gas. |
| Nov 14 1995 11:15:45:300AM | 951114010 | Steve Wolfe | Shot 951114010
Narrow the pg4 pulse and move it earlier by 15msec Plasma- Disrupted in flattop. Vertical instability. Could be the x-point control |
| Nov 14 1995 11:23:07:570AM | 951114011 | Steve Wolfe | Shot 951114011
PUt ZXL gain at 4 (hybrid units) fizzle; CII signal is about doubled to .03 |
| Nov 14 1995 11:39:42:040AM | 951114012 | Steve Wolfe | Shot 951114012
Reduce the PG4 by 1msec in width fizzle; PF crowbar OH2U seems to go first. Burnout still looks bad. CII down to .02 |
| Nov 14 1995 11:58:34:640AM | 951114013 | Steve Wolfe | Shot 951114013
Reduce the PG4 puff by another msec plasma - looked like it made it all the way through. Still a bad hesitation |
| Nov 14 1995 12:15:18:050PM | 951114014 | Steve Wolfe | Shot 951114014
Move plasma out to .665 from .655 fizzle PF crowbar - oh2u again Chopper IOC fault |
| Nov 14 1995 12:31:53:650PM | 951114015 | Steve Wolfe | Shot 951114015
Tweak EF4 a bit more negative (-1125 from -1115) plasma, full length. Breakdown looks better. X-point still high and inside |
| Nov 14 1995 12:53:52:240PM | 951114016 | Steve Wolfe | Shot 951114016
RXL out by 0.005 to -.005 ZXL gain to 30/sec Alternator has dropped its voltage to 13.1 (when?) fizzle. Bouncer at 14msec |
| Nov 14 1995 01:07:30:690PM | 951114017 | Steve Wolfe | Shot 951114017
No change. Looks good. Data system errors. Looks like no spectroscopy and no hybrid data Josh has recovered the data. vertical instability in rampdown. ZXL gain is left on? |
| Nov 14 1995 01:16:50:970PM | 951114018 | Steve Wolfe | Shot 951114018
Reduced ZXL gain in rampdown,and drew program to move up. Looks good. EF2L goes to zero early, EF4 swings back negative. x-poimt still inside and high, but go to 800kA shot anyway. |
| Nov 14 1995 01:45:36:890PM | 951114019 | Steve Wolfe | Shot 951114019
go to 800kA. Raise nl_04 to 1.0e20 plasma - disrupted at eof. Never got above 700kA RCUR takes a big jump outside at around 400msec. |
| Nov 14 1995 01:58:26:010PM | 951114020 | Steve Wolfe | Shot 951114020
Ask for gentler current rise. fizzle - pf crowbar Another chopper overcurrent. |
| Nov 14 1995 02:19:04:030PM | 951114021 | Steve Wolfe | Shot 951114021
Move pg4 puff earlier by 20msec. fizzle. Another EFc overcurrent. CII signal around .02 and no burnout. |
| Nov 14 1995 03:01:37:780PM | 951114022 | Steve Wolfe | Shot 951114022
Adjust early gain on ZCUR3 to prevent chopper oc Shorten PG4 puff by 0.5msec plasma - disrupted around 920msec EF3 acts like its on its current limit. PLC set point is 15kA, we are runnning around 6000A, but it won't provide more voltage than around 500V. |
| Nov 14 1995 06:10:42:720PM | 951114026 | Steve Wolfe | Shot 951114023-26
These were EF3 tests to demonstrate that the current regulator circuit is turning on too early. |
| Nov 14 1995 04:08:32:350PM | 951114027 | Steve Wolfe | Shot 951114027
Back to plasma - reload of shot 22 PLC limit set to 20kA on EF3 fizzle |
| Nov 14 1995 04:23:14:380PM | 951114028 | Steve Wolfe | Shot 951114028
Tweak EF4 a bit more negative. plasma - full length got 800kA , RCUR looks good. Density a bit soft. x-point a little high and inside |
| Nov 14 1995 04:31:59:410PM | 951114029 | Steve Wolfe | Shot 951114029
Ar puff - 20msec wide Move rxl 3mm out Raise nl_04 gain to 7 at .5sec fizzle - |
| Nov 14 1995 04:46:06:660PM | 951114030 | Steve Wolfe | Shot 951114030
Reduce pg4 by 0.5msec plasma - full length density better but not great. Early Current rise is very slow. |
| Nov 14 1995 04:54:14:070PM | 951114031 | Steve Wolfe | Shot 951114031
Tweak current and density to bring up a littlke earlier plasma - full length startup looks poor, bad hesitation, only gts to 60kA by 30msec density and current ok, maybe a little better than last time. |
| Nov 14 1995 05:00:39:210PM | 951114032 | Steve Wolfe | Shot 951114032
Tweak OH1 voltage to 100V from 130V at 5msec more Argon for JR disrupted earlier. early current rise looks worse. |
| Physics Operator Comments |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:48:53:090AM | Test | Ok | |
| 2 | 09:02:55:360AM | Test | Ok | |
| 3 | 09:17:54:620AM | Test | Ok | |
| 4 | 09:29:20:130AM | Test | Ok | gas puff test. |
| 5 | 09:35:38:660AM | Test | Ok | pulse gas test |
| 6 | 09:54:07:320AM | Test | Ok | pulse gas test |
| 7 | 10:07:01:920AM | Plasma | Ok | No faults |
| 8 | 10:24:47:730AM | Plasma | Ok | |
| 9 | 10:53:25:320AM | Plasma | Ok | |
| 10 | 11:05:45:700AM | Plasma | Ok | |
| 11 | 11:19:53:030AM | Plasma | Ok | |
| 12 | 11:31:57:860AM | Plasma | Ok | |
| 13 | 11:48:27:680AM | Plasma | Ok | |
| 14 | 12:05:37:570PM | Plasma | Ok | oh2u fault, efc ioc |
| 15 | 12:21:46:810PM | Plasma | Ok | |
| 16 | 12:41:59:430PM | Plasma | Ok | |
| 17 | 12:54:17:350PM | Plasma | Ok | |
| 18 | 01:09:30:060PM | Plasma | Ok | |
| 19 | 01:28:26:760PM | Plasma | Ok | |
| 20 | 01:54:49:430PM | Plasma | Ok | |
| 21 | 02:14:22:370PM | Plasma | Ok | |
| 22 | 02:29:26:850PM | Plasma | Ok | |
| 23 | 03:34:56:070PM | Test | Ok | |
| 24 | 03:43:01:940PM | Test | Ok | |
| 25 | 03:48:28:670PM | Test | Ok | |
| 26 | 03:55:57:120PM | Test | Ok | |
| 27 | 04:03:55:360PM | Plasma | Ok | |
| 28 | 04:13:42:740PM | Plasma | Ok | |
| 29 | 04:27:55:840PM | Plasma | Ok | |
| 30 | 04:37:29:170PM | Plasma | Ok | |
| 31 | 04:48:02:650PM | Plasma | Ok | |
| 32 | 04:56:05:220PM | Plasma | Ok | |