| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Steve Golovato |
| Physics operator(s): | Robert Granetz |
| Engineering operator(s): | Frank Silva,Vinny Bertolino |
| Engineering Operator Run Comment |
| 7.9 t granetz |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:15:117PM |
| Author: To Be Determined |
Run summary - 960207 SL: Golovato PO: Granetz EO: Silva/Bertolino Run 960131 - He3 minority heating at 8 T with boronized walls (continued) The goal of this 8 T run was to meaaure heating efficiency for 3He minority heating using derivative of diamagnetic stored energy at rf turnoff, doing this at several densities and 3He concentrations. Although the run started very late (12:30) because of alternator problems and had two test shots, two fiducials, one fizzle, and two 8T baseline shots out of 13 shots, it was still reasonably successful. We got the best h-modes yet at 8T, mainly because we were able to get h-modes at lower density, where we had gotten dithering in the past. This may indicate that the machine was cleaner (or better boronized), allowing access to h-mode at lower density, (nl04 around 0.8-0.9e20). This is still above the low density limit for h-mode at 5.3T. The concentration scan was on shots 6 (20ms 3He puff like on 960131), 8 (50ms puff like on 960117), and 9 (35ms, which gave about the same 3He level as was achieved on 960131 at 20ms and 960117 at 50ms). Keeping the 35ms puff, a density scan was done for shots 9 (nl04(prog)=1.e20), 10 (1.3e20), and 11-12 (0.8e20, 30ms puff). The last shot was the best, with the stored energy at 160kJ and still rising when d-port was notched out to get the absorbed power, and an h-factor of about 1.5 (assuming 100% power absorption). Shots 11 and 12 had radiated power fractions of less than a third, which are lower than on the higher density shots (9 and 10). Unfortunately, the goal of getting measurements of the absorbed power was probably not met very well. Since the time at which the field gets to 8T varies from t=0.5 to 0.8 sec, the baseline correction was not so correct. We hoped that some baselines would match some shots. Perhaps on more careful inspection, we'll be able to get some data (we did have 2 turnoffs per shot plus occasional interrupts). It's likely the error bars will be large. Future 8T runs should revisit the low density regime, tru again to get absorbed power data, and also try PEP mode at 8T. The cooling was much better with shots cycle times getting close to one per half hour, which is bearable. For information on engineering problems and shot statistics, see the physics operator summary. For shot-to-shot comments, see the logbook under the session_leader topic. |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:36:56:037PM |
| Author: To Be Determined |
| Physics operator's summary for run 960207. MP 117 -- ICRF heating at 7.9 T with He3 minority SL: S. Golovato PO: R. Granetz EO: F. Silva/V. Bertolino Today's run will again scan density and He3 concentration, and it is hoped that a direct determination of RF power deposition during H-mode will be possible by observing the derivative of the diamagnetism signal at the RF turnoff. This will require an 8 tesla baseline shot in order to compensate the diamagnetic measurement. Summary: The start of this run was delayed until noontime, due to problems with the alternator. The first plasma was a fiducial and it revealed serious problems in the latest TF filtering circuit. This was removed and replaced with the filtering circuit used yesterday. This filtering resulted in little or no reduction in the vibration of the alternator shaft at 8 tesla. The diamagnetic measurement seems to be completely out to lunch at 8 tesla. The residual TF pickup on the baseline shots is very different than on plasma shots. The error is very sensitive to the TF waveform, particularly to when the TF reaches flattop. This tends to vary noticeably even when the TF instrumentation shows virtually no differences in temperature. In general, the diamagnetic signal did not see much increase in stored energy during the RF, while EFIT calculated large increases. The RF heating today was very successful, with a maximum EFIT stored energy of 160 kJ (shot 012) and Prf=2.3 MW. It probably would have climbed even higher if we hadn't notched off the RF power. Density was scanned from nl_04=0.8 to 1.3e20 m-2, and H-modes were observed at all these densities. There was also a scan of He3 concentration. Scorecard: 8 plasmas 1 fizzles 2 TF-only baseline shots 2 tests (of new filtering board in TF supply) ---------- 13 total Run plan: (1) Fiducial shot (from 960206003) (2) No-plasma baseline shot at 8 tesla for diamagnetic compensation. Load from 960131011, but disable pre-pulse gas puff and TF fizzle control (3) 1 MA, 8 T plasma, w/He3. Load from 960131011. This shot includes x-point sweeping and RF feedback on RCUR Adjust He3 concentration as desired. Observe timing of H-modes. Set sharp RF turnoff at appropriate time during H-mode, well before TF inversion. Observe Wp and dWp/dt on compensated diamagnetic signal. If time allows, scan He3 concentration and ne. Engineering setup for Wednesday 07 Feb 1996: Discharge clean in deuterium for a couple of hours before the run A-side (actually K-side) plenum: 19-20 psi of deuterium B-top plenum: 5 psi of deuterium. B-side-lower plenum: 4 psi of argon. Confirm that B-side-upper plenum is already filled with 19-20 psi of Helium-3. (Assuming this plenum already contains Helium-3, don't purge it.). DISCONNECT THE PLC CONTROL OF THE VALVE! NINJA plenum: make sure this is pumped out. Enable hybrid control of A-side and B-top valves for start of run. Enable the ECE, VUV, Moly monitor, PCX, and TCX valves, assuming status of each is okay. Use engineering settings from shot 960206003 (a fiducial shot). After the fiducial, we will ask for the engineering settings from shot 960131011 (an 8 tesla, 1 MA shot). FRANK, before the actual run starts, Jim Irby may want to have a short TF-only pulse at 8 tesla to test the latest filtering. If so, he would want to do this around 08:00. It would be under PLC control. Detailed shot log: Shot 01 -- Test. TF only, under PLC control, 151 kA, test latest filtering IGOR failure. No data. Shot 02 -- Test. TF only, under PLC control, 151 kA, test latest filtering Shot 03 -- Fiducial shot. Good plasma, except there were 1 tesla oscillations on the TF flattop, at about 1.5 hertz. This latest filtering circuit is clearly unacceptable. Next shot: remove today's TF filter, reinsert yesterday's TF filter, and do another fiducial shot. Shot 04 -- Fiducial shot. Good plasma. Shot 05 -- Baseline shot at 8 tesla for diamagnetic compensation. The uncompensated diamagnetic signal is rather large. Shot 06 -- Plasma. First 8 T plasma today. Ip=1 MA. The TF waveform was a little different from the baseline shot, so the diamagnetic cancellation was very poor. Initial He3 pulse width = 20 ms. Next shot: increase initial He3 pulse width from 20 to 50 ms. Shot 07 -- Fizzle. Null looked okay. Next shot: reduce BR offset from 7.5 to 7.0 mT, just to do something. Also, disable the fizzle detector control of the TF, so that if we get another fizzle, it will also be another baseline shot. Shot 08 -- Plasma. Good shot, with long H-modes. RF purposely has a notch at t=0.85 s. The TF waveform looks very close to the baseline shot (005), but the compensation sucks. The only clear change in the slope of Wpdiam is at the H-L transition at 0.935 s. Wp_efit peaked at 150 kJ for this shot. Initial He3 pulse=50 ms. Next shot: reduce initial He3 pulse to 35 ms. Shot 09 -- Plasma. Good shot, RF notch again at 0.85 s. Diamagnetic signal again shows only the H-L transition. Initial He3 pulse=35 ms. Next shot: raise density to nl_04=1.3e20 m-2 (from 1.0e20). Shot 10 -- Plasma. Good shot. Got the higher density. The uncompensated diamagnetic signal actually bore some resemblance to the EFIT stored energy on this shot. There might even be some useful information in the derivative at the notch. It indicates the the absorbed RF power is about 40-50%. Initial He3 pulse=35 ms. Next shot: lower density to nl_04=0.8e20 m-2 and reduce initial He3 pulse to 30 ms. Shot 11 -- Plasma. Good shot. Got the lower density, and got H-mode. Initial He3 pulse=30 ms. Diamagnetic signal has gone back to being garbage again. The TF waveform was noticeably different than the last shot. (Vinnie fired the shot off early, compared to preceding shots, because all of the temperatures indicated the magnet was cooled, but this must not be the whole story.) Next shot: repeat with no changes Shot 12 -- Plasma. Good shot. Results are similar to the previous shot. EFIT's stored energy reaches 150 kJ. Shot 13 -- Baseline TF shot at 8 tesla for diamagnetic compensation. The diamagnetic signal looks very much like it did on the previous baseline shot (005), and nothing at all like it does on shots with plasma. My conclusion is that the measurement of stored energy with the diamagnetic loops at 8 tesla is not working, and the problem is not alleviated with TF baseline shots. End of run. |
| Session Leader Comments | |||
| Feb 7 1996 12:23:33:690PM | Steve Golovato | run 960207 - D(3He) heating at 8 T.
this run will be more abreviated than the usually 8T run because of alternator problems. run started about 12:30. goal - meaaure heating efficiency for 3He minority heating using derivative of diamagnetic stored energy at rf turnoff. do this at several densities and 3He concentrations. | |
| Feb 7 1996 12:24:47:010PM | 960207001 | Steve Golovato | shot 960207001 - tf test. failed.
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| Feb 7 1996 12:24:59:050PM | 960207002 | Steve Golovato | shot 960207002 - tf test. passed.
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| Feb 7 1996 12:51:08:740PM | 960207003 | Steve Golovato | shot 960207003 - fiducial.
plasma, tf oscillated from 5 to 5.8T with 1.5Hz period. a new filter was installed last night which will now be pulled out. |
| Feb 7 1996 12:59:09:970PM | 960207004 | Steve Golovato | shot 960207004 - another fiducial.
plasma, good fiducial. |
| Feb 7 1996 01:21:50:910PM | 960207005 | Steve Golovato | shot 960207005 - 8 T baseline shot, no plasma.
good baseline (hopefully). |
| Feb 7 1996 01:53:26:760PM | 960207006 | Steve Golovato | shot 960207006 - load shot 960131011, some tweaks to rf power waveforms.
nl04(prog)=1.e20, 20ms 3He puff, position feedback on, strike point sweeping enabled. plasma. no tci, nl feedback. 3He puff level about 3, was 5 on 960131 for these conditions. nl06 worked. got one h-mode until 1.02, when h-mode ending tripped d- then e-port rf. |
| Feb 7 1996 02:24:20:730PM | 960207007 | Steve Golovato | shot 960207007 - increase 3He puff to 50ms, like 960117 run.
tf reached full field at 780ms last shot, later than on baseline shot. interrupting d-port at 850ms for 50ms to get absorbed power in h-mode. tweaked tuning, raised power a little, would like 2.5MW instead of 2MW. fizzle. |
| Feb 7 1996 02:49:10:650PM | 960207008 | Steve Golovato | shot 960207008 - try again.
plasma. 2.36MW. h-mode persists during d-port interupt. variation in tf ramp makes baseline correction to diamagnetic signal difficult. 3He level for 50ms is 10, about 3.5 times 20ms level. getting hot spot on outer divertor during rf. h-mode end coincides with mini-injection as seeen on 2pi, not on moly monitor. |
| Feb 7 1996 03:27:41:080PM | 960207009 | Steve Golovato | shot 960207009 - lower 3He puff to 35ms. getting concentration scan.
plasma. 2.36MW. e-port strarted late, d can back out of interrupt late. made for lots of steps in power. |
| Feb 7 1996 05:08:32:840PM | 960207010 | Steve Golovato | shot 960207010 - raise nl04(prog) to 1.3e20 from 1.e20.
plasma. lost h-mode at d-port interrupt, need full power to maintain h-mode at this density. Prad/Ptot=45%. brick at 700ms kills first h-mode. |
| Feb 7 1996 04:11:48:850PM | 960207011 | Steve Golovato | shot 960207011 - lower nl04(prog) to .8e20, lower He3 puff to 30ms..
plasma. h-mode at lower nl04, first time at 8T. 2.36MW. 3He level=5.5, looks like about 12% n_3He/n_e. highest stored energy, 148kJ , Prad/Ptot about 25%. very good shot, H-factor about 1.3-1.4 assuming 100% absorbed power. |
| Feb 7 1996 04:43:45:220PM | 960207012 | Steve Golovato | shot 960207012 - repeat.
made mistake last shot, was about 7% 3He, not 12%. plasma. 3He level of 5, about 5-6% 3He. 160kj, 2.25MW. H-factor=1.5 (100% Prf) |
| Feb 7 1996 04:44:58:530PM | 960207012 | Steve Golovato | shot 960207012 - repeat.
made mistake last shot, was about 7% 3He, not 12%. plasma. 3He level of 5, about 5-6% 3He. 160kj, 2.25MW. H-factor=1.5 (100% Prf) |
| Feb 7 1996 04:59:31:890PM | 960207013 | Steve Golovato | shot 960207013 - another baseline for diamagnetic signal. shot 5
doesn't appear to be a very good baseline. |
| Physics Operator Comments | |||
| Feb 7 1996 09:32:23:140AM | Robert Granetz | MP 117 -- ICRF heating at 7.9 T with He3 minority
SL: S. Golovato PO: R. Granetz EO: F. Silva Today's run will again scan density and He3 concentration, and it is hoped that a direct determination of RF power deposition during H-mode will be possible by observing the derivative of the diamagnetism signal at the RF turnoff. This will require an 8 tesla baseline shot in order to compensate the diamagnetic measurement. | |
| Feb 7 1996 09:32:50:770AM | Robert Granetz | Run plan:
(1) Fiducial shot (from 960206003) (2) No-plasma baseline shot at 8 tesla for diamagnetic compensation. Load from 960131011, but disable pre-pulse gas puff and TF fizzle control (3) 1 MA, 8 T plasma, w/He3. Load from 960131011. This shot includes x-point sweeping and RF feedback on RCUR Adjust He3 concentration as desired. Observe timing of H-modes. Set sharp RF turnoff at appropriate time during H-mode, well before TF inversion. Observe Wp and dWp/dt on compensated diamagnetic signal. If time allows, scan He3 concentration and ne. | |
| Feb 7 1996 09:33:34:240AM | Robert Granetz | Engineering setup for Wednesday 07 Feb 1996:
Discharge clean in deuterium for a couple of hours before the run A-side (actually K-side) plenum: 19-20 psi of deuterium B-top plenum: 5 psi of deuterium. B-side-lower plenum: 4 psi of argon. Confirm that B-side-upper plenum is already filled with 19-20 psi of Helium-3. (Assuming this plenum already contains Helium-3, don't purge it.). DISCONNECT THE PLC CONTROL OF THE VALVE! NINJA plenum: make sure this is pumped out. Enable hybrid control of A-side and B-top valves for start of run. Enable the ECE, VUV, Moly monitor, PCX, and TCX valves, assuming status of each is okay. Use engineering settings from shot 960206003 (a fiducial shot). After the fiducial, we will ask for the engineering settings from shot 960131011 (an 8 tesla, 1 MA shot). | |
| Feb 7 1996 09:35:51:280AM | Robert Granetz | Before the actual run starts, Jim Irby may want to have a short
TF-only pulse at 8 tesla to test the latest filtering. If so, he would want to do this around 08:00. It would be under PLC control. | |
| Feb 7 1996 09:37:57:460AM | Robert Granetz | The start of this run was delayed by several hours due to a problem
with the alternator. | |
| Feb 7 1996 12:01:49:800PM | 960207001 | Robert Granetz | Shot 01 -- test. TF only, under PLC control, 151 kA, test latest filtering
IGOR failure. No data. |
| Feb 7 1996 12:20:49:450PM | 960207002 | Robert Granetz | Shot 02 -- Test. TF only, under PLC control, 151 kA, test latest filtering
|
| Feb 7 1996 12:51:07:400PM | 960207003 | Robert Granetz | Shot 03 -- Fiducial shot. Good plasma, except there were 1 tesla oscillations
on the TF flattop, at about 1.5 hertz. This latest filtering circuit is clearly unacceptable. Next shot: remove today's TF filter, reinsert yesterday's TF filter, and do another fiducial shot. |
| Feb 7 1996 01:02:37:710PM | 960207004 | Robert Granetz | Shot 04 -- Fiducial shot. Good plasma.
|
| Feb 7 1996 01:19:18:350PM | 960207005 | Robert Granetz | Shot 05 -- Baseline shot at 8 tesla for diamagnetic compensation. The
uncompensated diamagnetic signal is rather large. |
| Feb 7 1996 02:12:25:480PM | 960207006 | Robert Granetz | Shot 06 -- Plasma. First 8 T plasma today. Ip=1 MA. The TF waveform was
a little different from the baseline shot, so the diamagnetic cancellation was very poor. Initial He3 pulse width = 20 ms. Next shot: increase initial He3 pulse width from 20 to 50 ms. |
| Feb 7 1996 02:28:37:610PM | 960207007 | Robert Granetz | Shot 07 -- Fizzle. Null looked okay.
Next shot: reduce BR offset from 7.5 to 7.0 mT, just to do something. Also, disable the fizzle detector control of the TF, so that if we get another fizzle, it will also be another baseline shot. |
| Feb 7 1996 02:56:03:800PM | 960207008 | Robert Granetz | Shot 08 -- Plasma. Good shot, with long H-modes. RF purposely has a notch
at t=0.85 s. The TF waveform looks very close to the baseline shot (005), but the compensation sucks. The only clear change in the slope of Wpdiam is at the H-L transition at 0.935 s. Wp_efit peaked at 150 kJ for this shot. Initial He3 pulse=50 ms. Next shot: reduce initial He3 pulse to 35 ms. |
| Feb 7 1996 03:21:14:810PM | 960207009 | Robert Granetz | Shot 09 -- Plasma. Good shot, RF notch again at 0.85 s. Diamagnetic signal
again shows only the H-L transition. Initial He3 pulse=35 ms. Next shot: raise density to nl_04=1.3e20 m-2 (from 1.0e20). |
| Feb 7 1996 04:21:24:100PM | 960207010 | Robert Granetz | Shot 10 -- Plasma. Good shot. Got the higher density. The uncompensated
diamagnetic signal actually bore some resemblance to the EFIT stored energy on this shot. There might even be some useful information in the derivative at the notch. It indicates the the absorbed RF power is about 40-50%. Initial He3 pulse=35 ms. Next shot: lower density to nl_04=0.8e20 m-2 and reduce initial He3 pulse to 30 ms. |
| Feb 7 1996 04:29:23:060PM | 960207011 | Robert Granetz | Shot 11 -- Plasma. Good shot. Got the lower density, and got H-mode.
Initial He3 pulse=30 ms. Diamagnetic signal has gone back to being garbage again. The TF waveform was noticeably different than the last shot. (Vinnie fired the shot off early, compared to preceding shots, because all of the temperatures indicated the magnet was cooled, but this must not be the whole story.) Next shot: repeat with no changes |
| Feb 7 1996 04:41:39:490PM | 960207012 | Robert Granetz | Shot 12 -- Plasma. Good shot. Results are similar to the previous shot.
EFIT's stored energy reaches 150 kJ. |
| Feb 7 1996 05:09:58:650PM | 960207013 | Robert Granetz | Shot 13 -- Baseline TF shot at 8 tesla for diamagnetic compensation. The
diamagnetic signal looks very much like it did on the previous baseline shot (005), and nothing at all like it does on shots with plasma. My conclusion is that the measurement of stored energy with the diamagnetic loops at 8 tesla is not working, and the problem is not alleviated with TF baseline shots. End of run. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 11:57:44:010AM | Test | Bad | igor fail, no pulse |
| 2 | 12:08:55:520PM | Test | Ok | |
| 3 | 12:34:57:270PM | Plasma | Ok | tf feedback oscillation |
| 4 | 12:50:36:800PM | Plasma | Ok | |
| 5 | 01:05:58:520PM | Plasma | Ok | efc chopper ioc |
| 6 | 01:39:48:690PM | Plasma | Ok | |
| 7 | 02:14:20:580PM | Plasma | Ok | |
| 8 | 02:29:17:250PM | Plasma | Ok | |
| 9 | 03:00:58:260PM | Plasma | Ok | |
| 10 | 03:32:38:140PM | Plasma | Ok | |
| 11 | 03:53:09:230PM | Plasma | Ok | |
| 12 | 04:29:30:850PM | Plasma | Ok | |
| 13 | 04:57:43:960PM | Plasma | Ok | |