| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Unknown |
| Physics operator(s): | Joseph Snipes |
| Engineering operator(s): | Unknown |
| Engineering Operator Run Comment |
| Plasma conditioning to clean up walls in preparation for physics runs. S |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:37:11:740PM |
| Author: To Be Determined |
| Engineering setup for Friday, 18 August 2000 Overnight ECDC in D2, stopping 1-2 hours prior to the run. Run begins at 9:00 and ends at 17:00. Power system setup as on 1000816029. Gas setup - fill B-top with 6 psi of D2 Hybrid enabled fill B-side lower with 1 psi of Ar Hybrid disabled leave B-side upper as is Hybrid DISABLED fill C-side with 30 psi of D2 Hybrid enabled leave J-bottom as is Hybrid DISABLED The following gate valves should be enabled, assuming no vacuum problems: ECE, VUV Run Plan: More plasma conditioning to clean up the walls and prepare for physics runs with standard 0.8 MA, 5.2 T plasmas (and standard fizzles). Shot 1: Copied shot 1000817017. Dud! Shot 2: Increased pre-puff from 15 ms to 19 ms. Decreased EF4 current from -1300 A to -1277 A. Increased Br0 offset from 0.5 mT to 2 mT. Another Dud! OH2 oscillating at breakdown. EFC chopped wildly after 0.05 sec. Flux loop F25 failed. Shot 3: OH2 test to check out F25 flux loop. Still have a problem with 8212 digitizer for one of the OH1 signals. Will stop and replace it after the test shot(s). Test shot O.K. F25 looks fine for now. Shot 4: Replaced 8212 for OH1 voltage signal. Copied shot 1000817017 and increased pre-puff to 19 ms again. Good shot! Shot 5: Raised nl04 to 9 x 10^19 m^-3 after 0.5 sec and decreased pre-puff to 15 ms duration. Good shot. Got a bit more density than I wanted and it disrupted in the rampdown as a result. Shot 6: Repeat. Good shot. Still disrupted in the rampdown. Shot 7: Tweaked RCUR, CLEARIN, RXL, and ZXL after 1.5 s in the rampdown to see if we can avoid the disruption in the rampdown. Good shot. Still disrupted in the rampdown. Shot 8: Add a TF ramp for Zweben from 0.6 s to 1.0 s at 110 kA then ramp back up to 150 kA starting at 1.1 sec until 1.5 sec. Then, continue the TF rampdown. Tweaked the rampdown again making more gradual changes in RXL, ZXL, RXU, and ZXU. Good shot. Still disrupted in rampdown. Shot 9: Moved ZXU lower after 1.5 s to pull less on EF1, which hits its current limit in the rampdown. Reduced nl04 to 8 x 10^19 m^-2 and pulled it down at 1.4 sec to try to pump out faster in the rampdown. Disrupted earlier apparently due to a large MARFE. Shot 10: Reduced nl04 to 7 x 10^19 m^-2 and held it at 5 x 10^19 m^-2 until after 0.5 sec. Good shot. No longer have the MARFE. Density is lower and the plasma lasts longer. Still disrupts after 1.8 s. Shot 11: Made Bz more positive after a suggestion by Ian by decreasing EF4 current from -1300 A to -1285 A. Tweaked ZXU again in the rampdown to pull the upper X point out of the vessel. Disrupted early at cross-over at 0.3 s where there was a large injection on the previous shot. Shot 12: Tweaked RCUR and CLEARIN during cross-over to make more gradual changes at that sensitive time. Good shot. Shot 13: Tweaked rampdown again to try to keep the plasma diverted late into the rampdown. Moved TF ramp back to begin at 0.5 s to give a longer flattop at 4 T. Changed second TF flattop value to 100 kA. Good shot. Some signs of dithering at the low field, but still not quite H-mode. Shot 14: Removed Bt ramp. Put in an RCUR ramp instead from 0.6 s - 1.45 s ramping out to 0.672 m and back in to 0.663 m. Good shot. Shot 15: Ramped RCUR out to 0.676 m to attempt to touch the outboard limiter to check the EFIT calculations corrected with the outboard limiter coils. Good shot. Nominally touched the limiter according to the standard EFIT calculation. The calculation with the new limiter coils indicates that the outer gap is still about 6 mm. Shot 16: Ramped RCUR out by another 3 mm to 0.679 m and stay there from 0.8 to 0.9 s, which should just touch the limiter according to the new EFIT calculation with the limiter coils. Good shot. Zweben sees the He puff fluctuations move further out on this shot and there are some indications from the density and CII emission that we may now be just touching the limiter as expected from the new EFIT calculation with the limiter coils. Shot 17: Ramp RCUR out by another 2 mm to push hard against the outboard limiter to a radius of 0.681 m from 0.8 to 0.9 s. Good shot. It is difficult to tell whether the fluctuations keep moving out. Shot 18: Try a slow ramp in RCUR from 0.6 s to 0.975 s ramping out to 0.677 m then ramp back to 1.45 s and ramp further to 0.66 m. Dud! Shot 19: Try again with 19 ms of pre-puff and 0 Br0 offset. It may be that the sparker current was too low. Good shot. RCUR ramp is good, but still the results are unclear about whether or not we are touching the limiter. EF1 breaker pulled after the shot and was reset again. Shot 20: Copied shot 1000608006 in segment 2 to attempt Ohmic H-mode. Disrupted at 0.27 s. Probably some difference in RCUR offset from the old shot. Shot 21: Copied shot 1000818019 and then copied the TF waveform only from shot 1000608006 to attempt Ohmic H-mode. Fizzle! Shot 22: Decreased EF4 current from -1285 to -1270 A. Increased Br0 offset from 0 to 0.5 mT. PF breaker opened just before the shot. So, the shot was taken without power to the coils. Shot 23: Repeat with power. Fizzle! Shot 24: Try again with EF4 current set at -1290 A. Fizzle! Shot 25: Last try with EF4 current at -1295 A and 17 ms of pre-puff. Good shot. Perhaps some dithering but no H-mode. Accidentally left the gap scan in from shot 19 together with the TF ramp from 1000608006. Shot,Duration(s),Ipmax(MA) Shot,Duration(s),Ipmax 1 0.000 0.015 2 0.000 0.016 3 0.000 0.016 4 1.948 0.805 5 1.693 0.802 6 1.691 0.805 7 1.687 0.799 8 1.653 0.802 9 1.407 0.787 10 1.832 0.807 11 0.313 0.748 12 1.854 0.805 13 1.880 0.805 14 1.874 0.802 15 1.812 0.805 16 1.875 0.805 17 1.883 0.802 18 0.000 0.019 19 1.857 0.802 20 0.288 0.780 21 0.000 0.026 22 0.000 0.003 23 0.000 0.032 24 0.000 0.032 25 1.798 0.798 Finished summary for 1000818 Total of 25 shots. 25 shots. 17 plasmas. 3 fizzles. 3 duds. 2 test shots Summary: Overall it was a very good run considering that it was only the second day of operation. While the machine was not quite clean enough to get Ohmic H-mode, we did get a fair number of full length shots (14 good shots) without the fizzles in between, though we did suffer several fizzles at the end of the run. At the beginning of the run, there was a problem with flux loop F25 that perhaps cost us two shots. Granetz fiddled with the connectors and the integrator board and it seems to be working now. The PF breakers opened twice as well, which is an intermittent fault condition. Some useful high spatial resolution edge fluctuation measurements were made with Stewart Zweben's fast camera and some interesting comparisons of the new and old EFIT calculations with and without the limiter coils during outer gap scans also may shed some light on the whereabouts of the last closed flux surface to within a couple of mm. We are ready to boronize and get H-mode operation back. |
| Session Leader Comments |
| Physics Operator Comments | |||
| Aug 18 2000 08:32:01:590AM | 1000818001 | Joseph Snipes | Engineering setup for Friday, 18 August 2000 Overnight ECDC in D2, stopping 1-2 hours prior to the run. Run begins at 9:00 and ends at 17:00. Power system setup as on 1000816029. Gas setup - fill B-top with 6 psi of D2 Hybrid enabled fill B-side lower with 1 psi of Ar Hybrid disabled leave B-side upper as is Hybrid DISABLED fill C-side with 30 psi of D2 Hybrid enabled leave J-bottom as is Hybrid DISABLED The following gate valves should be enabled, assuming no vacuum problems: ECE, VUV Run Plan: More plasma conditioning to clean up the walls and prepare for physics runs with standard 0.8 MA, 5.2 T plasmas (and standard fizzles). |
| Aug 18 2000 09:16:20:060AM | 1000818001 | Joseph Snipes | Shot 1: Copied shot 1000817017. Dud! |
| Aug 18 2000 11:09:44:123AM | 1000818002 | Joseph Snipes | Shot 2: Increased pre-puff from 15 ms to 19 ms. Decreased EF4 current from -1300 A to -1277 A. Increased Br0 offset from 0.5 mT to 2 mT. Another Dud! OH2 oscillating at breakdown. EFC chopped wildly after 0.05 sec. Flux loop F25 failed. |
| Aug 18 2000 11:09:58:293AM | 1000818003 | Joseph Snipes | Shot 3: OH2 test to check out F25 flux loop. Still have a problem with 8212 digitizer for one of the OH1 signals. Will stop and replace it after the test shot(s). Test shot O.K. F25 looks fine for now. |
| Aug 18 2000 11:10:07:373AM | 1000818004 | Joseph Snipes | Shot 4: Replaced 8212 for OH1 voltage signal. Copied shot 1000817017 and increased pre-puff to 19 ms again. Good shot! |
| Aug 18 2000 11:10:20:717AM | 1000818005 | Joseph Snipes | Shot 5: Raised nl04 to 9 x 10^19 m^-3 after 0.5 sec and decreased pre-puff to 15 ms duration. Good shot. Got a bit more density than I wanted and it disrupted in the rampdown as a result. |
| Aug 18 2000 11:21:59:500AM | 1000818006 | Joseph Snipes | Shot 6: Repeat. Good shot. Still disrupted in the rampdown. |
| Aug 18 2000 11:43:03:670AM | 1000818007 | Joseph Snipes | Shot 7: Tweaked RCUR, CLEARIN, RXL, and ZXL after 1.5 s in the rampdown to see if we can avoid the disruption in the rampdown. Good shot. Still disrupted in the rampdown. |
| Aug 18 2000 12:05:34:873PM | 1000818008 | Joseph Snipes | Shot 8: Add a TF ramp for Zweben from 0.6 s to 1.0 s at 110 kA then ramp back up to 150 kA starting at 1.1 sec until 1.5 sec. Then, continue the TF rampdown. Tweaked the rampdown again making more gradual changes in RXL, ZXL, RXU, and ZXU. Good shot. Still disrupted in rampdown. |
| Aug 18 2000 12:25:37:670PM | 1000818009 | Joseph Snipes | Shot 9: Moved ZXU lower after 1.5 s to pull less on EF1, which hits its current limit in the rampdown. Reduced nl04 to 8 x 10^19 m^-2 and pulled it down at 1.4 sec to try to pump out faster in the rampdown. Disrupted earlier apparently due to a large MARFE. |
| Aug 18 2000 12:34:02:123PM | 1000818010 | Joseph Snipes | Shot 10: Reduced nl04 to 7 x 10^19 m^-2 and held it at 5 x 10^19 m^-2 until after 0.5 sec. Good shot. No longer have the MARFE. Density is lower and the plasma lasts longer. Still disrupts after 1.8 s. |
| Aug 18 2000 12:53:38:560PM | 1000818011 | Joseph Snipes | Shot 11: Made Bz more positive after a suggestion by Ian by decreasing EF4 current from -1300 A to -1285 A. Tweaked ZXU again in the rampdown to pull the upper X point out of the vessel. Disrupted early at cross-over at 0.3 s where there was a large injection on the previous shot. |
| Aug 18 2000 01:19:26:983PM | 1000818012 | Joseph Snipes | Shot 12: Tweaked RCUR and CLEARIN during cross-over to make more gradual changes at that sensitive time. Good shot. |
| Aug 18 2000 01:43:53:903PM | 1000818013 | Joseph Snipes | Shot 13: Tweaked rampdown again to try to keep the plasma diverted late into the rampdown. Moved TF ramp back to begin at 0.5 s to give a longer flattop at 4 T. Changed second TF flattop value to 100 kA. Good shot. Some signs of dithering at the low field, but still not quite H-mode. |
| Aug 18 2000 01:54:20:733PM | 1000818014 | Joseph Snipes | Shot 14: Removed Bt ramp. Put in an RCUR ramp instead from 0.6 s - 1.45 s ramping out to 0.672 m and back in to 0.663 m. Good shot. |
| Aug 18 2000 02:19:03:107PM | 1000818015 | Joseph Snipes | Shot 15: Ramped RCUR out to 0.676 m to attempt to touch the outboard limiter to check the EFIT calculations corrected with the outboard limiter coils. Good shot. Nominally touched the limiter according to the standard EFIT calculation. The calculation with the new limiter coils indicates that the outer gap is still about 6 mm. |
| Aug 18 2000 02:39:37:607PM | 1000818016 | Joseph Snipes | Shot 16: Ramped RCUR out by another 3 mm to 0.679 m and stay there from 0.8 to 0.9 s, which should just touch the limiter according to the new EFIT calculation with the limiter coils. Good shot. Zweben sees the He puff fluctuations move further out on this shot and there are some indications from the density and CII emission that we may now be just touching the limiter as expected from the new EFIT calculation with the limiter coils. |
| Aug 18 2000 03:04:19:420PM | 1000818017 | Joseph Snipes | Shot 17: Ramp RCUR out by another 2 mm to push hard against the outboard limiter to a radius of 0.681 m from 0.8 to 0.9 s. Good shot. It is difficult to tell whether the fluctuations keep moving out. |
| Aug 18 2000 03:17:52:840PM | 1000818018 | Joseph Snipes | Shot 18: Try a slow ramp in RCUR from 0.6 s to 0.975 s ramping out to 0.677 m then ramp back to 1.45 s and ramp further to 0.66 m. Dud! |
| Aug 18 2000 03:46:39:170PM | 1000818019 | Joseph Snipes | Shot 19: Try again with 19 ms of pre-puff and 0 Br0 offset. It may be that the sparker current was too low. Good shot. RCUR ramp is good, but still the results are unclear about whether or not we are touching the limiter.EF1 breaker pulled after the shot and was reset again. |
| Aug 18 2000 03:56:58:280PM | 1000818020 | Joseph Snipes | Shot 20: Copied shot 1000608006 in segment 2 to attempt Ohmic H-mode. Disrupted at 0.27 s. Probably some difference in RCUR offset from the old shot. |
| Aug 18 2000 04:08:19:467PM | 1000818021 | Joseph Snipes | Shot 21: Copied shot 1000818019 and then copied the TF waveform only from shot 1000608006 to attempt Ohmic H-mode. Fizzle! |
| Aug 18 2000 04:26:53:890PM | 1000818022 | Joseph Snipes | Shot 22: Decreased EF4 current from -1285 to -1270 A. Increased Br0 offset from 0 to 0.5 mT. PF breaker opened just before the shot. So, the shot was taken without power to the coils. |
| Aug 18 2000 04:38:35:560PM | 1000818023 | Joseph Snipes | Shot 23: Repeat with power. Fizzle! |
| Aug 18 2000 04:59:36:873PM | 1000818024 | Joseph Snipes | Shot 24: Try again with EF4 current set at -1290 A. Fizzle! |
| Aug 18 2000 05:35:53:513PM | 1000818025 | Joseph Snipes | Shot 25: Last try with EF4 current at -1295 A and 17 ms of pre-puff. Good shot. Perhaps some dithering but no H-mode. Accidentally left the gap scan in from shot 19 together with the TF ramp from 1000608006. |
| Aug 18 2000 05:51:09:857PM | 1000818025 | Joseph Snipes | 1 0.000 0.015 2 0.000 0.016 3 0.000 0.016 4 1.948 0.805 5 1.693 0.802 6 1.691 0.805 7 1.687 0.799 8 1.653 0.802 9 1.407 0.787 10 1.832 0.807 11 0.313 0.748 12 1.854 0.805 13 1.880 0.805 14 1.874 0.802 15 1.812 0.805 16 1.875 0.805 17 1.883 0.802 18 0.000 0.019 19 1.857 0.802 20 0.288 0.780 21 0.000 0.026 22 0.000 0.003 23 0.000 0.032 24 0.000 0.032 25 1.798 0.798 Finished summary for 1000818 Total of 25 shots. 25 shots. 17 plasmas. 3 fizzles. 3 duds. 2 test shots |
| Aug 18 2000 05:51:28:890PM | 1000818025 | Joseph Snipes | Summary: Overall it was a very good run considering that it was only the second day of operation. While the machine was not quite clean enough to get Ohmic H-mode, we did get a fair number of full length shots (14 good shots) without the fizzles in between, though we did suffer several fizzles at the end of the run. At the beginning of the run, there was a problem with flux loop F25 that perhaps cost us two shots. Granetz fiddled with the connectors and the integrator board and it seems to be working now. The PF breakers opened twice as well, which is an intermittent fault condition. Some useful high spatial resolution edge fluctuation measurements were made with Stewart Zweben's fast camera and some interesting comparisons of the new and old EFIT calculations with and without the limiter coils during outer gap scans also may shed some light on the whereabouts of the last closed flux surface to within a couple of mm. We are ready to boronize and get H-mode operation back. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:56:16:623AM | Plasma | Ok | |
| 2 | 09:20:07:060AM | Plasma | Ok | |
| 3 | 10:03:35:733AM | Test | Ok | OH tuesday test for flux loop check |
| 4 | 10:33:40:153AM | Plasma | Ok | |
| 5 | 10:57:07:250AM | Plasma | Ok | |
| 6 | 11:19:34:030AM | Plasma | Ok | |
| 7 | 11:34:24:793AM | Plasma | Ok | |
| 8 | 11:54:23:233AM | Plasma | Ok | |
| 9 | 12:09:27:263PM | Plasma | Ok | |
| 10 | 12:26:27:733PM | Plasma | Ok | |
| 11 | 12:43:48:170PM | Plasma | Ok | |
| 12 | 01:08:46:717PM | Plasma | Ok | |
| 13 | 01:31:51:733PM | Plasma | Ok | |
| 14 | 01:52:23:717PM | Plasma | Ok | |
| 15 | 02:09:42:340PM | Plasma | Ok | |
| 16 | 02:30:52:873PM | Plasma | Ok | |
| 17 | 02:51:01:327PM | Plasma | Ok | |
| 18 | 03:12:28:250PM | Plasma | Ok | |
| 19 | 03:26:38:653PM | Plasma | Ok | |
| 20 | 03:49:04:607PM | Plasma | Ok | |
| 21 | 04:06:45:623PM | Plasma | Ok | |
| 22 | 04:20:24:327PM | Plasma | Bad | EF1L Type one Flt, PF Breaker opened during Init |
| 23 | 04:36:30:327PM | Plasma | Ok | |
| 24 | 04:51:44:733PM | Plasma | Ok | |
| 25 | 05:01:47:890PM | Plasma | Ok | |