| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Rejean Boivin,Spencer Pitcher |
| Physics operator(s): | Joseph Snipes |
| Engineering operator(s): | Unknown |
| Engineering Operator Run Comment |
| Entered by josh |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:21:850PM |
| Author: To Be Determined |
NO ECDC before the run Physics run plan: Oct. 28th, first 1/2 before and after C-SPan Run at low density (in deuterium!) Start at 6e19 nl_04, and go down until we run out of power to go in H-mode. Gap of 0.8-1.0 cm, 1.0 MA, 5.3 T Monitor gaps/edge pedestal as we go up the low density limit up turn. C-Span took a good bite out of the run-time in the morning, and many fizzles (see phys-op summary) reduced the number of usable shots to a few. As observed before, the power and temperature thresholds went up considerably at lower density to the point where we couldn't see H-modes any longer with the available power. We observed small elms at very low density, seemingly type III, which is unusual at low density, but has been seen on DIII-D, especially shots 004-006. Edge temperatures, and consequent pedestals were very hot, we were able to fit in a few TF waggles for the GPC to scan the pedestal. Be careful of Michelson, as Amanda noticed a few saturated cases (see her entries in the logbook). However, as suspected the density rise is very slow and in some cases very difficult to see. In fact on shot 006 (and neighbors), the transition is very difficult to discern, and some usual give-aways are not marking the LH transition. shots: nl_04(e20) 004 0.5-0.55 005 0.5 006 0.4 007 0.3-0.4 (short) 010 0.4 011 0.6 012 0.7-0.8 013 0.8 014 0.9-1.0 Shot 011 maybe interesting as velocity at the edge maybe larger than usually (to double check). The switch run to Spencer for second part at 2PM. |
| Entered: Jul 7 2004 03:49:22:053PM |
| Author: To Be Determined |
| Flapper Excercises SL S Pitcher PO J Snipes Start with a discharge like: 990902009 1000 kA, 5.4 T, nl04 = 1.0, deuterium, Ohmic - establish basic discharge, compare flapper open/closed - investigate localization of flapper effects, i.e. operate flaps B,C only - investigate argon spectroscopy in the divertor Summary: The machine did not run very well this afternoon. Problems with run-aways primarily. We succeeded in seeing with Boswell's camera a diffuse glow over the H-J flap when it alone opened in shot 24. There was some evidence that the B-bottom pressure can be reduced using only the flappers on either side of B, but this is not really that clear. ---------------------------------------------------------- shot 15 plasma current 1 MA, dithering, H-mode 18 800 kA, runaways, density drifting up 19 bypass open whole shot 21 dynamic flapping, flaps C and H at 1.0 s 23 dynamic flapping, all flaps at 1.0 s 24 dynamic flapping, flap J at 1.0s Boswell sees diffuse glow over flap J (ie at H-J) 26 dynamic flapping, flaps B and C on either side of B-bottom at 1.0s |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:37:09:817PM |
| Author: To Be Determined |
| Engineering Setup for Thursday, 991028: Run will begin at 09:00 and end at 17:00 with an interruption by C-Span in the morning. Setup power supplies from shot 991027012 (1.0 MA, 5.3 T, flattop to 1.5 s, extended Bt flattop at 50 kA, fizzle detector off at t=1.7 s). No ECDC before the run to keep the walls unloaded. Gas setup - fill B-top with 6 psi of D2 Hybrid enabled fill B-side lower with 1 psi of Ar Hybrid DISABLED fill B-side upper with 10 psi of H2 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 The run will begin with MP 142 Low-density H-mode(1/2) Boivin where we will return to deuterium plasmas and investigate the H-mode low density limit. So, we will be running as low a density plasmas as possible yet attempting to avoid runaways. The second half of the run will be MP 209 Flapper exercise (1/2) CSP. Summary The machine ran quite well today, but the physics results left something to be desired. There were a number of fizzles, I think because of poor vessel conditioning. Low densities were achieved, but with large radiated power. Some H-modes were achieved with 4 times the usual threshold power with nl04 down as low as 5 x 10^19 m^-2. The flapper experiment had little success because of a number of fizzles and runaway discharges. Overnight ECDC in deuterium may help to improve machine conditioning. Considering that there was a 2 hour delay for C-SPAN, we did achieve a fair amount today nonetheless. 26 shots 18 plasmas 7 fizzles 1 EF1 test Shot 1: EF1 only test shot to test a chip replacement in the EF1 circuit. Shot 2: Loaded shot 991027013. Then, moved RCUR out by 1 mm to reduce the outer gap to 1 cm. Reduced nl04 to 6 x 10^19 m^-2 as Rejean requested. Turned off maintenance deuterium gas level after 0.33 s to attempt to get as low a density as possible relying on the feedback gas only. Disrupted at 0.25 s. Shot 3: Repeat. Fizzle! Shot 4: Increased EF4 current at t = 0 from -1290 to -1305 to match the previous time point and decrease Bz at breakdown by 1 mT. Also increased pre-puff by 4 ms to 26 ms duration. There is a pause for C-SPAN TV to go in the cell and film C-Mod. Plasma. Shot 5: Good shot. Another Type III ELMy H-mode from 0.6 - 0.82 s. Shot 6: Modified the rampdown to try to keep the equilibrium more constant to avoid the early disruption. Disrupted even earlier at 1.08 s. Type III ELMy H-mode from 0.6 - 0.85 s. Shot 7: Disrupted at 0.675 s during RF. Perhaps RF induced impurity injection. Shot 8: Fizzle! Shot 9: Bz is increasing shot to shot by about 1 mT per shot at breakdown. So, I'm reducing EF4 current by 30 A from -1305 to -1335 A to compensate. Also put in a Bt step of 8 kA from 0.7 to 0.82 s for the ECE sweep. Fizzle! Shot 10: Disrupted at 1 s. Still poor current rise with a hesitation. Runaway discharge with lots of hard x rays. Shot 11: Increased pre-puff by 1 ms to try to keep the runaways down. Increased density to 7 x 10^19 m^-2 on nl04. Still had runaways. Disrupted at 0.93 s. Shot 12: Increased pre-puff by 2 ms to 26 ms to try to keep the runaways down. Increased density to 9 x 10^19 m^-2 on nl04. Still has runaways. Density not staying up to 9 x 10^19 m^-2. Disrupted at 1.6 s. Shot 13: Repeat. Still has runaways. Bad hesitation in the current rise. Disrupted at 1.63 s. Shot 14: Raised nl04 to 1 x 10^20 m^-2 and returned the maintenance gas from C side to its normal level during the discharge. Increased prepuff by another 2 ms to 28 ms duration to eliminate the runaways. Reduced EF4 current from -1335 to -1320 A at breakdown. Better shot. Shot 15: Now going to MP209 Flapper exercise with CSP as session leader. Copied segment 2 from shot 990902009 and then put in the TF porch at the end of the shot. Density is at 1 x 10^20 m^-2. Good shot. Shot 16: Lowered Ip to 0.8 MA. Increased RCUR by 1.5 mm to 0.6695 m to reduce the outer gap. EF4 current reduced from -1320 to -1300 A to try to improve the current rise. Fizzle! Shot 17: Carbon high at breakdown. Late breakdown. Try returning EF4 current to -1320 A. Reduce pre-puff by 3 ms to 25 ms duration. Fizzle! Shot 18: Lowered Br0 to - 1 mT. Plasma went, but just barely. Lots of runaways. Shot 19: Increased pre-puff by 2 ms to 28 ms duration. Increased EF4 current from -1320 to -1335 A. Still has runaways and ohmic H-mode. Shot 20: Increased Br0 by 0.5 mT to -0.5 mT. Increased EF4 current to -1350 A at breakdown. Increased pre-puff by 2 ms to 30 ms duration. Put in a 2.5 mm ramp in RCUR to try to keep a constant outer gap at 1.5 cm. Also reduced ramp in CLEARIN by 1 mm to keep the inner gap constant. Changed the rampdown to try to avoid the disruption in the rampdown by attempting to keep the plasma near its flattop values through the early part of the rampdown. Fizzle! Shot 21: Reduced pre-puff by 5 ms to 25 ms duration. Good shot. Shot 22: Decreased pre-puff by 3 ms to 22 ms duration since the hard x rays are down now and there is still a hesitation in the current rise. Moved RXL out during the rampdown to try to prevent the disruption in the rampdown. Added 10 V maintenance gas from 0.5 to 1 s. Fizzle! Shot 23: Decreased EF4 current from -1350 to -1335 A. Runaways again. Shot 24: Copied TF programming from segment 1 of shot 991028014 into the model to have a hard turn on for the TF as it had been before shot 15. Runaways still present, but lower. O.K. shot. We'll go with this. Shot 25: Repeat. Bad runaways from the start. Prad increases dramatically and leads to a disruption at 0.31 s. The camera shows something fell in from the top of the J port antenna. Shot 26: Repeat. Good shot. |
| Session Leader Comments | |||
| Oct 28 1999 12:26:31:373PM | Rejean Boivin | Low density H modes Start at nl_04 ~0.6 e20 with maximum power available to get H mode. Lower density a little bit to see the upturn in edge temp and power. Then reconnect with previous experiments at slightly higher power, 0.7 to 1.0 e20. | |
| Oct 28 1999 11:23:36:403AM | 991028004 | Rejean Boivin | 004 Low density shot, Barely got an H mode Medium power, lost #2 at 0.7 sec. Increase power and retune for next shot. |
| Oct 28 1999 12:14:39:107PM | 991028005 | Rejean Boivin | 005 NL_04 ~5e19, nice H modes with elms during high power RF pulse. next shot bring power up a bit/retune |
| Oct 28 1999 12:12:55:547PM | 991028006 | Rejean Boivin | 006 NL_04 ~5e19, still got H-modes with elms. next shot, lower density |
| Oct 28 1999 12:52:33:687PM | 991028010 | Rejean Boivin | 010 NL_04 ~0.5e20 Barely dithering at this density with all the power we have. next shot go back up in density. |
| Oct 28 1999 01:52:24:140PM | 991028011 | Rejean Boivin | 011 NL_04 ~0.6e20 go back up in density a bit. |
| Oct 28 1999 01:52:03:140PM | 991028012 | Rejean Boivin | 012 NL_04 ~0.8e20 some elm-free H modes, retune for next shot |
| Oct 28 1999 01:51:37:653PM | 991028013 | Rejean Boivin | 013 NL_04 ~0.8e20 Nicer H modes elm-free |
| Oct 28 1999 01:51:09:763PM | 991028014 | Rejean Boivin | 014 NL_04 ~1.0e20 Nice H modes, tripping 2, on mismatch almost EDA at some point but not much power left. |
| Oct 28 1999 02:21:25:187PM | 991028015 | Spencer Pitcher | Taking Over......Flapper Exercises establish standard shot like 990902009 right gap too large, dithering, then H-mode next shot drop plasma current |
| Oct 28 1999 03:04:05:437PM | 991028018 | Spencer Pitcher | Taking Over......Flapper Exercises plasma current 0.8 kA runaways, density drifting up |
| Oct 28 1999 03:13:29:920PM | 991028019 | Spencer Pitcher | bypass open for whole shot |
| Oct 28 1999 03:17:02:857PM | 991028020 | Spencer Pitcher | bypass closed for whole shot |
| Oct 28 1999 05:26:16:467PM | 991028021 | Spencer Pitcher | dynamic flapping @ t = 1.0 s, flaps C and H only open at 1.0 s |
| Oct 28 1999 03:55:56:717PM | 991028022 | Spencer Pitcher | dynamic flapping @ t = 1.0 s, all flaps |
| Oct 28 1999 04:27:09:750PM | 991028023 | Spencer Pitcher | dynamic flapping @ t = 1.0 s, all flaps |
| Oct 28 1999 04:38:51:437PM | 991028024 | Spencer Pitcher | dynamic flapping @ t = 1.0 s, only flap H-J Boswell sees diffuse glow above flapper at H-J |
| Oct 28 1999 05:18:27:340PM | 991028026 | Spencer Pitcher | dynamic flapping @ t = 1.0 s, only flaps A-B, B-C |
| Physics Operator Comments | |||
| Oct 28 1999 08:17:23:967AM | Joseph Snipes | Engineering Setup for Thursday, 991028: Run will begin at 09:00 and end at 17:00 with an interruption by C-Span in the morning. Setup power supplies from shot 991027012 (1.0 MA, 5.3 T, flattop to 1.5 s, extended Bt flattop at 50 kA, fizzle detector off at t=1.7 s). No ECDC before the run to keep the walls unloaded. Gas setup - fill B-top with 6 psi of D2 Hybrid enabled fill B-side lower with 1 psi of Ar Hybrid DISABLED fill B-side upper with 10 psi of H2 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 The run will begin with MP 142 Low-density H-mode(1/2) Boivin where we will return to deuterium plasmas and investigate the H-mode low density limit. So, we will be running as low a density plasmas as possible yet attempting to avoid runaways. The second half of the run will be MP 209 Flapper exercise (1/2) CSP. | |
| Oct 28 1999 09:43:24:123AM | 991028001 | Joseph Snipes | Shot 1: EF1 only test shot to test a chip replacement in the EF1 circuit. |
| Oct 28 1999 09:42:39:873AM | 991028002 | Joseph Snipes | Shot 2: Loaded shot 991027013. Then, moved RCUR out by 1 mm to reduce the outer gap to 1 cm. Reduced nl04 to 6 x 10^19 m^-2 as Rejean requested. Turned off maintenance deuterium gas level after 0.33 s to attempt to get as low a density as possible relying on the feedback gas only. Disrupted at 0.25 s. |
| Oct 28 1999 09:44:05:623AM | 991028003 | Joseph Snipes | Shot 3: Repeat. Fizzle! |
| Oct 28 1999 09:56:13:297AM | 991028003 | Joseph Snipes | Shot 4: Increased EF4 current at t = 0 from -1290 to -1305 to match the previous time point and decrease Bz at breakdown by 1 mT. Also increased pre-puff by 4 ms to 26 ms duration. There is a pause for C-SPAN TV to go in the cell and film C-Mod. |
| Oct 28 1999 11:37:18:140AM | 991028004 | Joseph Snipes | Shot 4: Good shot. Brief Type III ELMy H-mode from 0.66 - 0.71 s. The threshold appears to be at P/(nBS) = 0.09, about 4 times our usual threshold. |
| Oct 28 1999 11:40:15:653AM | 991028004 | Joseph Snipes | Shot 4: Increased EF4 current at t = 0 from -1290 to -1305 to match the previous time point and decrease Bz at breakdown by 1 mT. Also increased pre-puff by 4 ms to 26 ms duration. There is a pause for C-SPAN TV to go in the cell and film C-Mod. |
| Oct 28 1999 11:36:39:640AM | 991028005 | Joseph Snipes | Shot 5: Good shot. Another Type III ELMy H-mode from 0.6 - 0.82 s. |
| Oct 28 1999 11:46:50:717AM | 991028006 | Joseph Snipes | Shot 6: Modified the rampdown to try to keep the equilibrium more constant to avoid the early disruption. Disrupted even earlier at 1.08 s. Type III ELMy H-mode from 0.6 - 0.85 s. |
| Oct 28 1999 12:25:39:687PM | 991028007 | Joseph Snipes | Shot 7: Disrupted at 0.675 s during RF. Perhaps RF induced impurity injection. |
| Oct 28 1999 12:26:15:840PM | 991028008 | Joseph Snipes | Shot 8: Fizzle! |
| Oct 28 1999 12:26:53:797PM | 991028009 | Joseph Snipes | Shot 9: Bz is increasing shot to shot by about 1 mT per shot at breakdown. So, I'm reducing EF4 current by 30 A from -1305 to -1335 A to compensate. Also put in a Bt step of 8 kA from 0.7 to 0.82 s for the ECE sweep. Fizzle! |
| Oct 28 1999 12:56:10:827PM | 991028010 | Joseph Snipes | Shot 10: Disrupted at 1 s. Still poor current rise with a hesitation. Runaway discharge with lots of hard x rays. |
| Oct 28 1999 12:57:59:420PM | 991028011 | Joseph Snipes | Shot 11: Increased pre-puff by 1 ms to try to keep the runaways down. Increased density to 7 x 10^19 m^-2 on nl04. Still had runaways. Disrupted at 0.93 s. |
| Oct 28 1999 01:21:34:497PM | 991028012 | Joseph Snipes | Shot 12: Increased pre-puff by 2 ms to 26 ms to try to keep the runaways down. Increased density to 9 x 10^19 m^-2 on nl04. Still has runaways. Density not staying up to 9 x 10^19 m^-2. Disrupted at 1.6 s. |
| Oct 28 1999 01:30:17:640PM | 991028013 | Joseph Snipes | Shot 13: Repeat. Still has runaways. Bad hesitation in the current rise. Disrupted at 1.63 s. |
| Oct 28 1999 01:57:44:623PM | 991028014 | Joseph Snipes | Shot 14: Raised nl04 to 1 x 10^20 m^-2 and returned the maintenance gas from C side to its normal level during the discharge. Increased prepuff by another 2 ms to 28 ms duration to eliminate the runaways. Reduced EF4 current from -1335 to -1320 A at breakdown. Better shot. |
| Oct 28 1999 02:04:48:890PM | 991028015 | Joseph Snipes | Shot 15: Now going to MP209 Flapper exercise with CSP as session leader. Copied segment 2 from shot 990902009 and then put in the TF porch at the end of the shot. Density is at 1 x 10^20 m^-2. Good shot. |
| Oct 28 1999 02:21:12:590PM | 991028016 | Joseph Snipes | Shot 16: Lowered Ip to 0.8 MA. Increased RCUR by 1.5 mm to 0.6695 m to reduce the outer gap. EF4 current reduced from -1320 to -1300 A to try to improve the current rise. Fizzle! |
| Oct 28 1999 02:40:34:590PM | 991028017 | Joseph Snipes | Shot 17: Carbon high at breakdown. Late breakdown. Try returning EF4 current to -1320 A. Reduce pre-puff by 3 ms to 25 ms duration. Fizzle! |
| Oct 28 1999 02:55:59:030PM | 991028018 | Joseph Snipes | Shot 18: Lowered Br0 to - 1 mT. Plasma went, but just barely. Lots of runaways. |
| Oct 28 1999 03:16:36:937PM | 991028019 | Joseph Snipes | Shot 19: Increased pre-puff by 2 ms to 28 ms duration. Increased EF4 current from -1320 to -1335 A. Still has runaways and ohmic H-mode. |
| Oct 28 1999 03:30:14:077PM | 991028020 | Joseph Snipes | Shot 20: Increased Br0 by 0.5 mT to -0.5 mT. Increased EF4 current to -1350 A at breakdown. Increased pre-puff by 2 ms to 30 ms duration. Put in a 2.5 mm ramp in RCUR to try to keep a constant outer gap at 1.5 cm. Also reduced ramp in CLEARIN by 1 mm to keep the inner gap constant. Changed the rampdown to try to avoid the disruption in the rampdown by attempting to keep the plasma near its flattop values through the early part of the rampdown. Fizzle! |
| Oct 28 1999 03:41:22:797PM | 991028021 | Joseph Snipes | Shot 21: Reduced pre-puff by 5 ms to 25 ms duration. Good shot. |
| Oct 28 1999 03:59:00:780PM | 991028022 | Joseph Snipes | Shot 22: Decreased pre-puff by 3 ms to 22 ms duration since the hard x rays are down now and there is still a hesitation in the current rise. Moved RXL out during the rampdown to try to prevent the disruption in the rampdown. Added 10 V maintenance gas from 0.5 to 1 s. Fizzle! |
| Oct 28 1999 04:25:43:780PM | 991028023 | Joseph Snipes | Shot 23: Decreased EF4 current from -1350 to -1335 A. Runaways again. |
| Oct 28 1999 04:44:09:670PM | 991028024 | Joseph Snipes | Shot 24: Copied TF programming from segment 1 of shot 991028014 into the model to have a hard turn on for the TF as it had been before shot 15. Runaways still present, but lower. O.K. shot. We'll go with this. |
| Oct 28 1999 05:02:02:310PM | 991028025 | Joseph Snipes | Shot 25: Repeat. Bad runaways from the start. Prad increases dramatically and leads to a disruption at 0.31 s. The camera shows something fell in from the top of the J port antenna. |
| Oct 28 1999 05:15:28:297PM | 991028026 | Joseph Snipes | Shot 26: Repeat. Good shot. |
| Oct 28 1999 05:16:00:233PM | 991028026 | Joseph Snipes | Summary The machine ran quite well today, but the physics results left something to be desired. There were a number of fizzles, I think because of poor vessel conditioning. Low densities were achieved, but with large radiated power. Some H-modes were achieved with 4 times the usual threshold power with nl04 down as low as 5 x 10^19 m^-2. The flapper experiment had little success because of a number of fizzles and runaway discharges. Overnight ECDC in deuterium may help to improve machine conditioning. Considering that there was a 2 hour delay for C-SPAN, we did achieve a fair amount today nonetheless. 26 shots 18 plasmas 7 fizzles 1 EF1 test |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 2 | 09:14:01:983AM | Plasma | Ok | (null) |
| 3 | 09:34:26:047AM | Plasma | Ok | (null) |
| 4 | 11:01:56:950AM | Plasma | Ok | (null) |
| 5 | 11:22:00:263AM | Plasma | Ok | (null) |
| 6 | 11:40:56:170AM | Plasma | Ok | (null) |
| 7 | 11:55:42:513AM | Plasma | Ok | (null) |
| 8 | 12:09:50:140PM | Plasma | Ok | (null) |
| 9 | 12:25:08:030PM | Plasma | Ok | (null) |
| 10 | 12:38:04:280PM | Plasma | Ok | (null) |
| 11 | 12:55:17:983PM | Plasma | Ok | (null) |
| 12 | 01:10:05:327PM | Plasma | Ok | (null) |
| 13 | 01:26:43:250PM | Plasma | Ok | (null) |
| 14 | 01:44:27:890PM | Plasma | Ok | (null) |
| 15 | 02:03:03:060PM | Plasma | Ok | (null) |
| 16 | 02:19:31:483PM | Plasma | Ok | (null) |
| 17 | 02:32:55:500PM | Plasma | Ok | (null) |
| 18 | 02:48:24:623PM | Plasma | Ok | (null) |
| 19 | 03:06:14:827PM | Plasma | Ok | (null) |
| 20 | 03:23:31:717PM | Plasma | Ok | (null) |
| 21 | 03:39:46:217PM | Plasma | Ok | (null) |
| 22 | 03:56:52:873PM | Plasma | Ok | (null) |
| 23 | 04:14:26:390PM | Plasma | Ok | (null) |
| 24 | 04:32:19:607PM | Plasma | Ok | (null) |
| 25 | 04:51:40:513PM | Plasma | Ok | (null) |
| 26 | 05:10:01:950PM | Plasma | Ok | (null) |