| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Robert Granetz |
| Physics operator(s): | John Goetz |
| Engineering operator(s): | Joe Daigle |
| Engineering Operator Run Comment |
| plasma run |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:08:587PM |
| Author: To Be Determined |
| Physics operator and Session leader summary for 930915 EO: Daigle PO: Goetz SL: Granetz This run was based on MP019 - Plasma Current Feedback Control. The plan for the day was to explore controller space to determine if a controller for plasma current could be constructed. The controllers tried were: OH1 only (shots 1-6); OH1 and the OH2's (shots 7-19); and OH1, OH2's, and EF3's (shots 20-30). The double swing capability of the supplies allowed this run to be more successful than the previous attempts at current control. All three controllers used showed signs of being successful. Due to Lenz's law, the current in the coil(s) must decrease in order to raise Ip to the programmed value and keep it there. Thus, when only OH1 was being used to control Ip, it's current would drop substantially with respect to the OH2's and EF1's. This resulted in the plasma elongation increasing throughout the discharge, eventually reaching kappa=1.6 and disrupting vertically. These disruptions are typically very fast, with many shots having 0.8 < dIp/dt < 1.0 MA/msec today. These fast disruptions at high currents (0.5 - 0.6 MA) caused breakdown problems on subsequent shots. The OH2's and EF1's were added in to the Ip controller in an attempt to reduce the growth of kappa by keeping the OH1/OH2/EF1 ratios more stable. Due to power supply voltage limitations in EF1 (-200 volt max inversion), the currents in that coil pair could not decrease as fast as we needed, so we never quite got a stable kappa for an entire shot. The plasma current was flat-topped on shots 4, 6, 7, 17, 19, 20, and 29. A number of these discharges lasted longer than 0.75 s. The new record for pulse length is 0.91 s, set on shot 29. The current on that one flattopped at 0.603 MA. Shot 29 was actually long enough that the programmed current rampdown was observed, although it terminated in a disruption halfway down the ramp (the beginning of the rampdown was aprrox. 50 msec after the programmed time). The gain in the feedback was increased only slightly during the day and the final value was never tested (on shot 30) because of the radiation induced disruption that ended the discharge early. This gain along with the ratio of OH1, OH2, and EF1 M-gains need to be explored further. Today was a very poor day for startup, partly due to the hard disruptions and/or the vacuum cleanliness/ wall conditioning. The current rises (when they occured) were ratty and the start times were not very reproducible. Much tweaking of the EF4 and Br_0 controllers was done. All filling and fueling was done with the A_SIDE piezo valve. Engineering troubles today: The STATE machine may have come out of PULSE on shot 14 and disabled the gates to the power supplies causing single phasing of all supplies. A tweak of the EF1 supply late in the day allowed more voltage output and thus allowed the EF1 currents to more closely follow the requested waveforms (although this tweak ocurred too late in the day to be fully exploited). No vacuum troubles today, although the cleanliness was very poor as indicated by radiated power and Zeff. Scorecard: 30 shots = 12 plasmas + 15 fizzles + 1 system test + 2 duds Records: Longest pulse length to date, 0.91 s on shot 29. Most coulombs, on shot 29 (flattop Ip=0.603 MA) Shot summary for 930915 Reload of 930914019 Changes: RCUR from 0.69 to 0.68 IC_EF1's from 2700 to 2300 from 0.15 to 0.35 IP = 500000 from .26 to .75 IP controller consists of OH1 with a gain of -2.6e-4; P gain = 2 @ 0.15 PULSE_GAS_3 waveform doing all the fueling 1 P_0=1.2e-5 (from A_SIDE) fizzle 2 P_IP=1 fizzle 3 S_BR_0=9e-3 (from 7.5) plasma 4 PULSE_GAS_3 lowered early in time plasma 5 IC_EF1's to 2100 @ .15 and 1800 @ .35; increase PULSE_GAS_3 fizzle 6 P_0=1.3e-5 plasma 7 P_0=1.4e-5 add OH2's to IP controller; M=-5.2e-5 plasma 8 P_0=1.5e-5 IC_EF1's = 1500 @ .35 and 0 @ .8 fizzle 9 P_0=1.3e-5 fizzle 10 P_0=1.2e-5 move PULSE_GAS_3 waveform to +2msec fizzle 11 IC_EF4 to 1000 from 1050 @0. move PULSE_GAS_3 waveform to 0. fizzle 12 IC_EF4 to 1090 from 1000 @ 0. plasma 13 IC_EF4 to 1075 move PULSE_GAS_3 to +5msec and lower to 45V fizzle 14 IC_EF4 to 1090 dud 15 test of STATE info test 16 try again fizzle 17 P_0=1.1e-5 load PULSE_GAS_3 from 007 plasma 18 P_0=1.2e-5 IC_EF1's 1400@.4 & -1000@.8 S_IP=650000 fizzle 19 P_0=1.1e-5 plasma 20 P_0=1.3e-5 add EF1's to IP controller M=-1.7e-4; P_IP=2@.5 plasma 21 V_EF1's to -100 from .35 to .8 P_IP=2 @.15 more early fuel fizzle 22 IC_EF1 to 500A @ .4 increase EF1's in M_IP to -3.4e-4 fizzle 23 P_0=1.1e-5 plasma 24 IC_EF4 to 1060A reload PULSE_GAS_3 from 020 dud 25 IC_EF4 to 1040A P_0=1.3e-5 fizzle 26 S_BR_0 = 7.5e-3 P_BR_0=1 P_0=1.2e-5 fizzle 27 S_BR_0=8.0e-3 IC_EF4=1020 plasma 28 lower fueling (60 to 40) fizzle 29 raise fueling (to 50) start at .02 plasma 30 V_EF1 @-100 to 1. sec IC_EF1 to -2000A IP=750000 P_IP to 3 plasma |
| Physics Operator Summaries |
| Session Leader Comments | |||
| Sep 15 1993 09:25:00:120AM | 930915001 | Robert Granetz | Start with the last shot of yesterday, except enable Ip feedback using OH1
only in the controller, and reduce EF1's so that plasma is not extremely elongated. Gas programming is done using the A-side fast valve only. |
| Sep 15 1993 09:27:26:520AM | 930915001 | Robert Granetz | Fizzle. Vacuum fields were fair. OH1 tried to get 0.5 MA of plasma current
by dropping its current to -20 kA. This caused the OH2's to increase to about +25 kA. For the next shot, reduce gain on Ip feedback to 1 (it was 2 for this shot). No other changes. I assume that the fizzle was due to wall conditions. |
| Sep 15 1993 09:48:55:770AM | 930915002 | Robert Granetz | Another fizzle. There is a radial field of -1.5 mT, which will be corrected
for the next shot. There is also some discrepancy in the reconstructed vacuum flux between Ian's and Steve Wolfe's analyses. |
| Sep 15 1993 10:02:09:950AM | 930915003 | Robert Granetz | Plasma, but pretty ugly. Ip=0.2 MA, duration=0.24 s, ending with a disruption.
Presumably the gas puffing is too high, since the density reached nl=5e19 by t=0.1 s. For the next shot, the early gas puff will be reduced from 60 to 40 volts. |
| Sep 15 1993 10:19:25:200AM | 930915004 | Robert Granetz | Good shot. Ip=0.5 MA (actually 0.484 MA, flattopped), duration=0.63 s.
The plasma becomes very elongated (kappa=1.6) and disrupts vertically upward at 0.635 s. There were a lot of hard x-rays starting at 0.1 s. For the next shot, reduce EF1 currents by about 3 kA from 0.25 s onward. Also increase gas puff. |
| Sep 15 1993 10:32:17:880AM | 930915004 | Robert Granetz | The vertical disruption was quite fast...dI/dt=-0.78 MA/ms.
|
| Sep 15 1993 10:34:45:080AM | 930915005 | Robert Granetz | Fizzle (post-disruption fizzle). We should have remembered to increase the
pre-fill slightly. For the next shot, increase it from 1.2 to 1.3e-5 torr. There seems to be a problem with the interferometer data acquisition. |
| Sep 15 1993 11:00:04:490AM | 930915006 | Robert Granetz | Ip=0.45 MA, disrupted vertically at 0.54 s. Hard x-rays were nearly gone.
Elongation still reached 1.6. This might be due to having only OH1 in the Ip controller, which causes the ratio of OH2/OH1 to climb. For the next shot, include the OH2's in the Ip controller at a value equal to the turns ratio for M. Also increase the pre-fill from 1.3 to 1.4e-5 because of the disruption on this shot. |
| Sep 15 1993 11:15:12:440AM | 930915007 | Robert Granetz | Good shot. Ip=0.50 MA with good flattop. Ended in a disruption at 0.58 s,
again due to kappa getting up to 1.6. This time, however, it took much longer for kappa to get to that value, so including the OH2's in the Ip controller worked. Now the problem seems to be due to the EF1's. For the next shot, instead of including the EF1's in the Ip controller, let's just program their demand currents down by about 1 kA later in the shot. Also increase the pre-fill again from 1.4 to 1.5e-5 (because of the disruption on this shot), and increase the early gas puffing as well (there were lots of hard x-rays on this shot). |
| Sep 15 1993 11:17:20:090AM | 930915007 | Robert Granetz | There was no EFC on this shot. Vertical position seemed to be okay until
kappa got close to 1.6. |
| Sep 15 1993 11:18:04:650AM | 930915008 | Robert Granetz | Fizzle. For the next shot, reduce the pre-fill from 1.5 to 1.3e-5.
|
| Sep 15 1993 11:37:23:890AM | 930915009 | Robert Granetz | Fizzle again. Null seems to be acceptable. For the next shot, reduce
pre-fill again from 1.3 to 1.2e-5, and also undo some of the recent pulse gas programming changes. |
| Sep 15 1993 11:47:14:820AM | 930915010 | Robert Granetz | Fizzle. Vertical field at breakdown was +2 mT, so for the next shot, reduce
EF4 current by 50 amps (from 1050 to 1000 A). |
| Sep 15 1993 11:48:30:370AM | 930915010 | Robert Granetz | Also for the next shot, re-install the small gas puff changes, on the
assumption that the previous fizzles were not due to gas, but rather to the Bz error. |
| Sep 15 1993 12:06:06:770PM | 930915011 | Robert Granetz | Fizzle again. Not a good looking null, although Bz did drop by 2 mT. Well,
since we don't know what we're doing, let's try increasing Bz by 2 mT instead (i.e. add about 4 mT from where we are now). For the next shot, EF4 will be increased from 1000 to 1090 A. |
| Sep 15 1993 12:17:10:330PM | 930915012 | Robert Granetz | Plasma, but pretty ugly...very disruptive and short. Ip=0.24 MA,
duration=0.3 s. Density was quite high early on. For the next shot, reduce the gas puffing. Also reduce EF4 from 1090 to 1075. Leave the pre-fill at 1.2e-5 torr. |
| Sep 15 1993 12:32:33:900PM | 930915013 | Robert Granetz | Fizzle. Must have been the 15 amp change in EF4? For the next shot, add the
15 amps back to EF4 (from 1075 to 1090 A). Leave gas programming the same. |
| Sep 15 1993 01:00:00:420PM | 930915014 | Robert Granetz | TF started single phasing before t=0, and then crowbarred at t=0. There was
a weird sound in the power room, apparently due to the TF single phasing. All other supplies shutdown at the TF crowbar, but no breakers came out. Many diagnostics had camac which didn't trigger, including the engineering stuff, the hybrid, and many DAQ1 things. The hybrid output voltages may have also been screwed up. |
| Sep 15 1993 01:24:32:380PM | 930915014 | Robert Granetz | Apparently the state PLC changed to RECOOL in the middle of PULSE, causing a
loss of the enable bit to all the supplies. |
| Sep 15 1993 01:27:23:410PM | 930915015 | Robert Granetz | Test shot without alternator power. Everything seems to be okay.
|
| Sep 15 1993 01:49:41:240PM | 930915016 | Robert Granetz | Fizzle. Null is acceptable. For the next shot tweak the pre-fill down from
1.2 to 1.1e-5 torr. |
| Sep 15 1993 01:52:50:160PM | 930915016 | Robert Granetz | The pulse gas programming for shot 007 will be copied and used for the
next shot. |
| Sep 15 1993 02:09:57:800PM | 930915017 | Robert Granetz | Finally, a plasma. And a good one too! Ip=0.50 MA, duration=0.81 s, a
new pulse length record! The plasma still disrupts vertically due to the gradually increasing kappa. No density on this shot. For the next shot: a) Decrease EF1 currents by 1000 A (at 0.8 s, programming will be changed from 0 to -1000 A, at 0.4 s no change). b) Increase Ip demand from 0.50 to 0.65 MA c) Increase pre-fill from 1.1 to 1.2e-5 torr. |
| Sep 15 1993 02:20:49:620PM | 930915018 | Robert Granetz | Fizzle. Usual after a big disruption. For the next shot, just reduce the
pre-fill from 1.2 to 1.1e-5 (it's like popping bubble sheet...it just makes us feel better). |
| Sep 15 1993 02:38:51:000PM | 930915019 | Robert Granetz | Good shot, Ip=0.53 MA, duration=0.795 s. Ended with a vertical disruption.
EF1 doesn't seem to follow its current programming very well. Hard x-rays were not too bad on that shot. For the next shot: put EF1 into the Ip controller, at its turns ratio. Increase pre-fill to 1.3e-5. Increase the PID gain on Ip from 1 to 2 at t=0.5 s. P.S. The EFC faulted out at 0.78 s, which is then quickly followed by the vertical disruption (kappa=1.6+ during that time). |
| Sep 15 1993 02:55:28:730PM | 930915020 | Robert Granetz | Good shot. Ip=0.56 MA, duration=0.78 s. Still ends with a vertical disruption
due to kappa=1.6. Hard x-rays are not too bad after 0.2 s. Plasma was disruptive before 0.2 s. For the next shot, decrease the EF1 voltage pre-programming by 100 volts from t=0.35 to 0.80 s. Change the PID gain on Ip from 1 to 2 for the entire shot (not just after 0.5 s). Increase gas puffing a little during the first 0.25 s. |
| Sep 15 1993 03:13:24:770PM | 930915020 | Robert Granetz | Very fast disruption...dI/dt=-0.97 MA/ms !
|
| Sep 15 1993 03:08:09:340PM | 930915021 | Robert Granetz | Fizzle. Post-disruption fizzle? Leave the gas and pre-fill the same for
the next shot. Also for the next shot: decrease EF1 current demand from 1400 to 500 amps at 0.4 s, and double the EF1 controller M value. |
| Sep 15 1993 03:15:22:030PM | 930915022 | Robert Granetz | Another fizzle. EF1 is still not behaving properly. For the next shot,
just decrease the pre-fill from 1.3 to 1.1e-5 torr. |
| Sep 15 1993 03:30:55:370PM | 930915023 | Robert Granetz | Ugly and short. For the next shot, re-load gas programming from shot 20,
and decrease EF4 current from 1090 to 1060 amps (to satisfy Ian's complaints about the breakdown occurring 4 msec too late. |
| Sep 15 1993 03:41:41:520PM | 930915024 | Robert Granetz | No breakdown at all. For the next shot, increase the pre-fill to 1.3e-5 from
1.1e-5 torr. |
| Sep 15 1993 03:57:33:510PM | 930915025 | Robert Granetz | Fizzle. For next shot, change Br gain from 3 to 1 in order to modify a
1 mT field during breakdown. Also reduce pre-fill from 1.3 to 1.2e-5 torr. |
| Sep 15 1993 04:13:17:760PM | 930915026 | Robert Granetz | Fizzle. On the next shot, bring Bz down by another 1 mT, using EF4.
|
| Sep 15 1993 04:27:27:200PM | 930915027 | Robert Granetz | Ugly and short. For the next shot, reduce the gas puff a little.
|
| Sep 15 1993 04:35:43:670PM | 930915028 | Robert Granetz | Fizzle. No changes for the next shot.
|
| Sep 15 1993 04:55:06:160PM | 930915029 | Robert Granetz | Great shot. Ipmax=0.60 MA, duration=0.91 s, a new pulse length record!
Current started ramping down at 0.8 s and got about halfway down before a vertical disruption. Kappa is still going to 1.6 late in the shot. For the next shot, extend voltage programming and current programming on EF1 to 1.1 s, and decrease EF1 current from -1 kA to -2 kA. Also increase Ip demand from 0.65 to 0.75 MA, add 100 ms to the rampup time for Ip, and increase the Ip PID gain from 2 to 3. |
| Sep 15 1993 05:00:22:630PM | 930915030 | Robert Granetz | Plasma, but not very long. Ip=0.48 MA, duration=0.28 s. Not a fast
disruption. There might have been a radiated power problem. Last shot of the day. |
| Physics Operator Comments |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:15:10:400AM | Plasma | Ok | Plasma shot no faults. |
| 2 | 09:28:18:180AM | Plasma | Ok | Plasma shot no faults. |
| 3 | 09:48:43:520AM | Plasma | Ok | Plasma shot O.K. OH1 More than one not conducting Fault. |
| 4 | 10:04:02:630AM | Plasma | Ok | Plasma shot no faults. |
| 5 | 10:23:33:670AM | Plasma | Ok | Plasma shot no faults. |
| 6 | 10:36:50:700AM | Plasma | Ok | Plasma shot good TF c-bar fault at end of flattop. |
| 7 | 10:57:22:530AM | Plasma | Ok | Plasma shot no faults |
| 8 | 11:13:29:070AM | Plasma | Ok | Plasma shot good. |
| 9 | 11:26:34:440AM | Plasma | Ok | Plasma shot good |
| 10 | 11:40:59:830AM | Plasma | Ok | Plasma shot Fizzle |
| 11 | 11:55:10:270AM | Plasma | Ok | Plasma shot no faults. |
| 12 | 12:08:42:630PM | Plasma | Ok | Plasma shot Good TF c-bar fault at end of flattop. |
| 13 | 12:27:18:930PM | Plasma | Ok | Plasma shot good |
| 14 | 12:41:25:900PM | Plasma | Bad | all supplies single phased. |
| 15 | 01:22:03:800PM | Test | Ok | data system test may have changed state atwrong time. |
| 16 | 01:41:02:000PM | Plasma | Ok | no faults |
| 17 | 01:54:24:440PM | Plasma | Ok | no faults 800msec plasma |
| 18 | 02:11:34:920PM | Plasma | Ok | plasma -- oh1 >1scr not conducting late in the shot |
| 19 | 02:21:58:040PM | Plasma | Ok | Good Shot |
| 20 | 02:40:34:680PM | Plasma | Ok | No Faults |
| 21 | 02:57:14:390PM | Plasma | Ok | plasma shot good |
| 22 | 03:10:36:630PM | Plasma | Ok | plasma shot good |
| 23 | 03:21:40:590PM | Plasma | Ok | plasma shot good |
| 24 | 03:34:45:140PM | Plasma | Ok | Plasma shot fizzle |
| 25 | 03:47:17:340PM | Plasma | Ok | Plasma shot O.K. |
| 26 | 04:01:32:060PM | Plasma | Ok | Plasma shot no faults. |
| 27 | 04:15:42:570PM | Plasma | Ok | Plasma shot No faults. |
| 28 | 04:28:56:200PM | Plasma | Ok | Plasma shot no faults. |
| 29 | 04:41:27:650PM | Plasma | Ok | Plasma shot O.K. |
| 30 | 04:56:02:990PM | Plasma | Ok | good |