| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Earl Marmar |
| Physics operator(s): | Joseph Snipes |
| Engineering operator(s): | Gary Dekow,Ed Fitzgerald |
| Engineering Operator Run Comment |
| MP#318 High Performance at 5.4 Tesla; SL:Marmar; PO:Snipes; EO:Dekow/Fit |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:33:117PM |
| Author: Earl Marmar |
| Session leader summary 1030611 MP 318: High performance H-Modes at 5 Tesla This run was another attempt to get high power, steady H-modes. One thing that is different about our best performance shots, compared with more recent ones, is that the upper triangularity was lower in the old shots. Examples of shots with stored energy greater than or equal to 200 kJ are 960116025, 960116027, 980217015 and 1001013002. We decreased upper triangularity to 0.3 for this run, without any obvious benefit. In order to try to get better EDA-ness, we ramped the toroidal field up to about 5.7 Tesla, starting with shot 7, and also tried ramping the current up after entering H-mode. What actually worked best to get fairly steady EDA was to increase the target density, starting with shot 17. Studying RF trips on some of the steadier shots reveals once again that a significant fraction of the RF power is not showing up in the plasma. Results for the dW/dt analysis on shots 6, 23 and 27 show that dW/dt is typically equal to around 45% of the change in the RF power at the trip. For comparison, on shot 960116027, a trip which reduced the RF power from 2.7 MW down to 1.4 MW shows a dW/dt ~ -1.2 MW, accounting for more than 90% of the power. Some conjectures that have been put forward with regard to the missing power: 1) The fast (~50 keV) ions are not being confined (error fields?) 2) Power is being lost to the edge (poor single pass absorption, effects of BN tiles, RF physics in the edge plasma,?) H/(H=D) was typically around 7% for this run. For comparison, 1001013002 had H/(H+D) of 7.5% at the time of maximum stored energy (W = 233 kJ, Prf = 4.9 MW), measured using the same balmer-alpha technique in both cases. Note that, as Martin points out, if only 50% of the RF is effective in heating, then radiated power fraction is much higher than we might think, and relatively low H factors would be consistent with our previous results at high radiated power fraction. The RF coupling, particularly for J-port, had problems at the higher target densities (nl04 ~ 1.2e20), although on the last shot of the day (27), J-port did work for part of the pulse. Something that may have helped was to delay the turn-on of J until the plasma was in H-Mode, at which time the midplane neutral pressure has decreased.For about 100 msec, j-port power was 1.7 MW and total RF power was 4.7 MW on this shot. |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:37:18:190PM |
| Author: Joseph Snipes |
| Engineering setup for Tuesday, 11 June 2003 Purpose: MP#318 High Performance at 5.4 Tesla Session leader: E. Marmar Physics operator: J. Snipes ECDC overnight in D2 at 2e-4 Torr, stopping by 07:00. Bake at 60 C overnight. Run begins at 09:00 and ends at 17:00. If RF has fired into the vacuum chamber prior to the start of the run, then we will need to do 10 minutes of ECDC before the first shot. Power systems setup the same as on 1030529016 (1 MA, 5.4 T, lower single null) A-coils should be hooked up as on 1030507027 (+Dtop -Dbot -Jtop +Jbot), and the power supply should be enabled. Gas setup: fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar Hybrid enabled (PG1) fill B-side upper with 10 psi D2 Hybrid DISABLED (PG2) (for ECDC) fill C-side with 30 psi D2 Hybrid enabled (PG3) Enable the following gate valves, assuming no vacuum problems: ECE, DNB ------------------------------------------------------------------------------- RF Setup: All 4 transmitters in Run On by 08:00. We want 5+ MW of ICRF. ------------------------------------------------------------------------------- Run Plan: Start by getting good EDA H-modes at 5.4 T, 1 MA, and 5 MW of ICRF (on-axis). We will start with nl04 = 1 x 10^20 m^-2. We will use the A-coils all the time to eliminate locked modes. ECDC should be ready for between-shot cleaning. We will run with a small outer gap at 0.7 cm and Z = -0.5 cm. If the H-modes are not good EDA's, we may increase the TF to 5.6 or even 5.8 T to go to higher q. Then, we will attempt to improve performance and get another neutron alert by the end of the day. One hour delay due to alternator oil tank problem. Summary: The machine ran pretty well once the alternator oil tank problem was resolved. The run started with shot 1030610028 due to a mistake by Josh. Shot 9 was a no power shot because the TCI laser failed in CHECK. There were H-modes on all shots, but confinement was poor. J-port did not work well at moderately high densities even though D and E produced better EDA H-modes then. Except for shot 28, the other shots today had horrible looking startups and there finally were a number of fizzles. Scorecard: 28 shots 24 plasmas 3 fizzles 1 no power failed TCI Shot 28: Copied shot 1030610027 but changed ZXU and RXU to reproduce 1001013002, which had lower upper triangularity. Also increased CLEARIN by 0.005 m at 0.43 s to attempt to avoid touching the inner wall at crossover. Good shot with several H-modes. Due to a Josh error, the first shot of 1030611 was written as 1030610028. Shot 01: After the mixup of shot 1030610028, we will name the second shot of today 1030611001. Reduced nl04 to 0.9 x 10^20 m^-2. Good shot with multiple H-modes again. Shot 02: Repeat. Good shot with multiple H-modes. Shot 03: Repeat. Good shot with multiple H-modes, perhaps a bit worse than the previous shots. Startup looks pretty bad, but it is still going, so Earl does not want me to change it for now. Shot 04: Repeat with a two step up of the ICRF. RF trips continuously. Multiple H-modes. Shot 05: Reduced Ip request to 0.95 MA. Good shot. Several H-modes. Shot 6: Repeat. Good shot with 4 H-modes. Shot 07: Increased CLEARIN by 0.005 m and increased RCUR by 0.0025 m to increase the inner gap by 0.5 cm. Also increased TF current by 10 kA from 0.6 s until 1.3 s. Good shot with 3 H-modes. Shot 08: Repeat except for stepping the RF up 0.1 s earlier. Good shot with a few H-modes. Shot 09: Reduced Br0 by 0.5 mT. No power shot since the TCI laser failed in CHECK. Shot 10: Try again. Good shot with multiple H-modes. Startup still bounces. Shot 11: Removed Br0 change returning it to 0. Loaded wire 14 from 1030514014 to change to NL_ZMETER density feedback rather than TCI. Programmed NL_ZMETER to 0.24 V. Good shot with 4 H-modes. Shot 12: Repeat. Good shot. Three EDA H-modes. Shot 13: Reduced NL_ZMETER to 0.2 V. Good shot with several H-modes. Shot 14: Reduced NL_ZMETER to 0.17 V and reduced argon puff from 35 to 20 ms duration. Good shot. Several H-modes. Shot 15: Increased prepuff by 2 ms to 25 ms duration. Good shot, but the data system failed so that most data were not taken. Shot 16: Good shot with lower density. Many brief H-modes more ELM-free. Shot 17: Raise NL_ZMETER to 0.4 V. Ramp Ip from 0.8 to 0.9 s up to 1.15 MA then hold there until 1.3 s. Good shot but RF trips considerably. A few brief H-modes. Shot 18: Repeat to tune RF. Good shot with several brief H-modes, but RF still trips. Shot 19: Repeat to tune RF. Good shot with several brief H-modes, but RF still trips. Fizzle! Shot 20: Decreased prepuff by 2 ms to 23 ms duration. Good shot, though there were some hard x rays early. Two H-modes, one EDA about 0.5 s long. Shot 21: Repeat to attempt to improve J-port coupling. Good shot with a long EDA H-mode similar to shot 20. Shot 22: Repeat. Fizzle! Shot 23: Reduced Br0 by 0.5 mT to -0.0005 T. Good shot similar to 20 and 21. Shot 24: Increased Ip to 1.35 MA and extended it out to 1.4 s. Disrupted at 1 s. Only reached 1.2 MA. Shot 25: Reload shot 23. Fizzle! Shot 26: Repeat. Good shot but with hard x rays early. Despite 3 MW of RF, the plasma remained in L-mode for much of the RF pulse, though there were H-modes early and late in the RF pulse. Some CAMAC problems. No H/D data. Shot 27: Repeat with fewer hard x rays. Good shot with a few H-modes. |
| Session Leader Comments | |||
| Jun 11 2003 09:13:33:820AM | Earl Marmar | MP 318: High performance at 5.4 Tesla Plan: Try to optimize at 1 MA, with 3 to 6 MW total ICRF looking back at our highest performance 1 MA shots, one difference that appears, compared to our recent campaigns, is that the upper triangularity was lower, around 0.3. The shots I looked at are 960116025, 960116027, 980217015, and 1001013002. We will start from the last shot yesterday, 1030610027, but decrease the upper triangularity. | |
| Jun 11 2003 11:20:28:197AM | 1030611003 | Earl Marmar | ratty H-mode; still looking too ELM-free; many back transitions steady RF for almost 400 msec; edge of j-port antenna appears to be spewing at 0.9s and after |
| Jun 11 2003 11:30:36:913AM | 1030611004 | Earl Marmar | reprogram RF to give 3 MW for .2 s, then increase to 4.5 MW similar ratty H-modes; more RF trips |
| Jun 11 2003 12:47:41:577PM | 1030611005 | Earl Marmar | drop Ip to 900 kA some evidence of EDA from reflectometer and PCI |
| Jun 11 2003 12:50:04:437PM | 1030611007 | Earl Marmar | increase TF during RF pulse, to 5.78 T (160 kA) in attempt to get more EDA-like RF slightly off-axis (~5 cm) Seems to heat in the center |
| Jun 11 2003 12:54:14:987PM | 1030611008 | Earl Marmar | move RF power increase 100 ms earlier; try to keep it from making the first back-transition at least 3 H-modes; second seems best; RF tripping 2'nd H-Mode looks EDA-ish; H89 ~ 1.25 at 5.1 MW RF power; Rdd = 2e13/sec |
| Jun 11 2003 01:17:59:083PM | 1030611010 | Earl Marmar | no changes first H-mode is the least bad; H89 ~ 1.2 |
| Jun 11 2003 01:47:10:107PM | 1030611012 | Earl Marmar | first H-mode is slightly better Rdd peaks at 2.5e13 /sec |
| Jun 11 2003 01:59:39:367PM | 1030611013 | Earl Marmar | lower target density by 10% no tci, but z-meter signal did not decrease slightly worse confinement (Rdd ~ 2.0e13 /sec) |
| Jun 11 2003 02:19:53:520PM | 1030611014 | Earl Marmar | repeat similar to 13; lots of rf trips; briefly at 5.4 MW, Rdd peaks at 2.4e13/sec |
| Jun 11 2003 03:05:23:650PM | 1030611017 | Earl Marmar | higher density (nl_04~1.2e20); put in a current ramp-up to 1.1 MA after in H-Mode not much difference; RF trips at 0.88s, Rdd = 1.6e13/sec |
| Jun 11 2003 03:21:00:770PM | 1030611018 | Earl Marmar | repeat definitely EDA H-modes, especially the second one. No J-port power; semi-decent H-mode with 2.9 MW from D and E |
| Jun 11 2003 03:52:51:077PM | 1030611020 | Earl Marmar | long 3 MW EDA H-modes; Rdd ~ 1.5e13/sec |
| Jun 11 2003 04:00:00:410PM | 1030611021 | Earl Marmar | repeat; similar to 20 |
| Jun 12 2003 04:22:14:697PM | 1030611023 | Earl Marmar | There was an RF trip (D port) on this shot, at 1.12 seconds, in the middle of a quite steady EDA H-Mode. The RF power dropped from 3 MW to about 1.6 MW. Bob Granetz ran EFIT on a 1 ms timescale (EFIT18 tree). It appears that at the RF power decrease, dW/dt ~ -0.6 MW +/- 0.1 MW. This can be compared with the decrease in RF power of 1.35 MW, possibly implying that only about 45% of the RF is being absorbed by the plasma. |
| Jun 11 2003 05:03:19:960PM | 1030611024 | Earl Marmar | try to ramp up to 1.3 MA Got to 1.2 MA, got stuck there and then disrupted; went outboard limited before the disruption. |
| Jun 11 2003 05:03:47:630PM | 1030611026 | Earl Marmar | back to settings from shot 23. Got 3 MW of RF with a very long l-mode period. |
| Jun 11 2003 05:28:40:447PM | 1030611027 | Earl Marmar | repeat. Got 5 MW for 80 msec, Rdd up to 2.7e13/sec, H89 ~ 1.0 H/(H+D) ~ 0.07 |
| Physics Operator Comments | |||
| Jun 11 2003 08:47:04:930AM | Joseph Snipes | Engineering setup for Tuesday, 11 June 2003 Purpose: MP#318 High Performance at 5.4 Tesla Session leader: E. Marmar Physics operator: J. Snipes ECDC overnight in D2 at 2e-4 Torr, stopping by 07:00. Bake at 60 C overnight. Run begins at 09:00 and ends at 17:00. If RF has fired into the vacuum chamber prior to the start of the run, then we will need to do 10 minutes of ECDC before the first shot. Power systems setup the same as on 1030529016 (1 MA, 5.4 T, lower single null) A-coils should be hooked up as on 1030507027 (+Dtop -Dbot -Jtop +Jbot), and the power supply should be enabled. Gas setup: fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar Hybrid enabled (PG1) fill B-side upper with 10 psi D2 Hybrid DISABLED (PG2) (for ECDC) fill C-side with 30 psi D2 Hybrid enabled (PG3) Enable the following gate valves, assuming no vacuum problems: ECE, DNB ------------------------------------------------------------------------------- RF Setup: All 4 transmitters in Run On by 08:00. We want 5+ MW of ICRF. ------------------------------------------------------------------------------- Run Plan: Start by getting good EDA H-modes at 5.4 T, 1 MA, and 5 MW of ICRF (on-axis). We will start with nl04 = 1 x 10^20 m^-2. We will use the A-coils all the time to eliminate locked modes. ECDC should be ready for between-shot cleaning. We will run with a small outer gap at 0.7 cm and Z = -0.5 cm. If the H-modes are not good EDA's, we may increase the TF to 5.6 or even 5.8 T to go to higher q. Then, we will attempt to improve performance and get another neutron alert by the end of the day. | |
| Jun 11 2003 10:21:32:510AM | Joseph Snipes | Shot 28: Copied shot 1030610027 but changed ZXU and RXU to reproduce 1001013002, which had lower upper triangularity. Also increased CLEARIN by 0.005 m at 0.43 s to attempt to avoid touching the inner wall at crossover. Good shot with several H-modes. Due to a Josh error, the first shot of 1030611 was written as 1030610028. | |
| Jun 11 2003 08:56:18:900AM | 1030611001 | Joseph Snipes | A problem appeared with an oil tank for the alternator so that the alternator is now spinning down. There will be a delay in the run. |
| Jun 11 2003 09:11:08:510AM | 1030611001 | Joseph Snipes | One hour to 1.5 hour delay due to the alternator oil tank problem. |
| Jun 11 2003 10:36:51:540AM | 1030611001 | Joseph Snipes | Shot 01: After the mixup of shot 1030610028, we will name the second shot of today 1030611001. Reduced nl04 to 0.9 x 10^20 m^-2. Good shot with multiple H-modes again. |
| Jun 11 2003 10:54:54:167AM | 1030611002 | Joseph Snipes | Shot 02: Repeat. Good shot with multiple H-modes. |
| Jun 11 2003 11:13:22:587AM | 1030611003 | Joseph Snipes | Shot 03: Repeat. Good shot with multiple H-modes, perhaps a bit worse than the previous shots. Startup looks pretty bad, but it is still going, so Earl does not want me to change it for now. |
| Jun 11 2003 11:29:16:057AM | 1030611004 | Joseph Snipes | Shot 04: Repeat with a two step up of the ICRF. RF trips continuously. Multiple H-modes. |
| Jun 11 2003 11:41:00:570AM | 1030611005 | Joseph Snipes | Shot 05: Reduced Ip request to 0.95 MA. Good shot. Several H-modes. |
| Jun 11 2003 12:04:41:010PM | 1030611006 | Joseph Snipes | Shot 6: Repeat. Good shot with 4 H-modes. |
| Jun 11 2003 12:09:12:970PM | 1030611007 | Joseph Snipes | Shot 07: Increased CLEARIN by 0.005 m and increased RCUR by 0.0025 m to increase the inner gap by 0.5 cm. Also increased TF current by 10 kA from 0.6 s until 1.3 s. Good shot with 3 H-modes. |
| Jun 11 2003 12:36:55:300PM | 1030611008 | Joseph Snipes | Shot 08: Repeat except for stepping the RF up 0.1 s earlier. Good shot with a few H-modes. |
| Jun 11 2003 12:44:52:870PM | 1030611009 | Joseph Snipes | Shot 09: Reduced Br0 by 0.5 mT. No power shot since the TCI laser failed in CHECK. |
| Jun 11 2003 01:10:38:000PM | 1030611010 | Joseph Snipes | Shot 10: Try again. Good shot with multiple H-modes. Startup still bounces. |
| Jun 11 2003 01:23:50:730PM | 1030611011 | Joseph Snipes | Shot 11: Removed Br0 change returning it to 0. Loaded wire 14 from 1030514014 to change to NL_ZMETER density feedback rather than TCI. Programmed NL_ZMETER to 0.24 V. Good shot with 4 H-modes. |
| Jun 11 2003 01:36:16:490PM | 1030611012 | Joseph Snipes | Shot 12: Repeat. Good shot. Three EDA H-modes. |
| Jun 11 2003 01:54:23:143PM | 1030611013 | Joseph Snipes | Shot 13: Reduced NL_ZMETER to 0.2 V. Good shot with several H-modes. |
| Jun 11 2003 02:03:31:227PM | 1030611014 | Joseph Snipes | Shot 14: Reduced NL_ZMETER to 0.17 V and reduced argon puff from 35 to 20 ms duration. Good shot. Several H-modes. |
| Jun 11 2003 02:30:37:047PM | 1030611015 | Joseph Snipes | Shot 15: Increased prepuff by 2 ms to 25 ms duration. Good shot, but the data system failed so that most data were not taken. |
| Jun 11 2003 02:45:04:887PM | 1030611016 | Joseph Snipes | Shot 16: Good shot with lower density. Many brief H-modes more ELM-free. |
| Jun 11 2003 03:01:40:650PM | 1030611017 | Joseph Snipes | Shot 17: Raise NL_ZMETER to 0.4 V. Ramp Ip from 0.8 to 0.9 s up to 1.15 MA then hold there until 1.3 s. Good shot but RF trips considerably. A few brief H-modes. |
| Jun 11 2003 03:20:18:537PM | 1030611019 | Joseph Snipes | Shot 18: Repeat to tune RF. Good shot with several brief H-modes, but RF still trips. |
| Jun 11 2003 03:24:57:977PM | 1030611019 | Joseph Snipes | Shot 19: Repeat to tune RF. Good shot with several brief H-modes, but RF still trips. Fizzle! |
| Jun 11 2003 03:39:31:130PM | 1030611020 | Joseph Snipes | Shot 20: Decreased prepuff by 2 ms to 23 ms duration. Good shot, though there were some hard x rays early. Two H-modes, one EDA about 0.5 s long. |
| Jun 11 2003 04:00:13:710PM | 1030611021 | Joseph Snipes | Shot 21: Repeat to attempt to improve J-port coupling. Good shot with a long EDA H-mode similar to shot 20. |
| Jun 11 2003 04:05:40:870PM | 1030611022 | Joseph Snipes | Shot 22: Repeat. Fizzle! |
| Jun 11 2003 04:22:28:180PM | 1030611023 | Joseph Snipes | Shot 23: Reduced Br0 by 0.5 mT to -0.0005 T. Good shot similar to 20 and 21. |
| Jun 11 2003 04:34:32:780PM | 1030611024 | Joseph Snipes | Shot 24: Increased Ip to 1.35 MA and extended it out to 1.4 s. Disrupted at 1 s. Only reached 1.2 MA. |
| Jun 11 2003 04:43:27:257PM | 1030611025 | Joseph Snipes | Shot 25: Reload shot 23. Fizzle! |
| Jun 11 2003 05:02:41:897PM | 1030611026 | Joseph Snipes | Shot 26: Repeat. Good shot but with hard x rays early. Despite 3 MW of RF, the plasma remained in L-mode for much of the RF pulse, though there were H-modes early and late in the RF pulse. Some CAMAC problems. No neutron and H/D data. |
| Jun 11 2003 05:09:22:027PM | 1030611027 | Joseph Snipes | Shot 27: Repeat with fewer hard x rays. Good shot with a few H-modes. |
| Jun 11 2003 05:13:39:360PM | 1030611027 | Joseph Snipes | Summary: The machine ran pretty well once the alternator oil tank problem was resolved. The run started with shot 1030610028 due to a mistake by Josh. Shot 9 was a no power shot because the TCI laser failed in CHECK. There were H-modes on all shots, but confinement was poor. J-port was unable to function at moderately high densities even though D and E produced better EDA H-modes then. So, it seems that J-port is a low density AT antenna, but not for conventional high performance shots at high density. Except for shot 28, the other shots today had horrible looking startups and there finally were a number of fizzles. Shot 27 was the worst startup that went in history! Scorecard: 28 shots 24 plasmas 3 fizzles 1 no power failed TCI |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 10:29:49:773AM | Plasma | Ok | |
| 2 | 10:42:28:807AM | Plasma | Ok | |
| 3 | 10:55:28:243AM | Plasma | Ok | |
| 4 | 11:23:23:290AM | Plasma | Ok | |
| 5 | 11:36:11:430AM | Plasma | Ok | |
| 6 | 11:49:02:963AM | Plasma | Ok | |
| 7 | 12:04:21:603PM | Plasma | Ok | |
| 8 | 12:26:26:340PM | Plasma | Ok | |
| 9 | 12:39:23:460PM | Plasma | Bad | Lost TCI Gas Laser Feedback, No Power Shot |
| 10 | 01:04:32:433PM | Plasma | Ok | |
| 11 | 01:18:25:117PM | Plasma | Ok | |
| 12 | 01:32:49:080PM | Plasma | Ok | |
| 13 | 01:45:52:200PM | Plasma | Ok | |
| 14 | 01:58:53:507PM | Plasma | Ok | |
| 15 | 02:25:01:633PM | Plasma | Ok | |
| 16 | 02:39:32:787PM | Plasma | Ok | |
| 17 | 02:52:39:327PM | Plasma | Ok | |
| 18 | 03:06:02:040PM | Plasma | Ok | |
| 19 | 03:19:53:427PM | Plasma | Ok | |
| 20 | 03:32:57:407PM | Plasma | Ok | |
| 21 | 03:49:36:340PM | Plasma | Ok | |
| 22 | 04:02:26:273PM | Plasma | Ok | |
| 23 | 04:15:21:063PM | Plasma | Ok | |
| 24 | 04:28:18:667PM | Plasma | Ok | |
| 25 | 04:41:35:020PM | Plasma | Ok | |
| 26 | 04:54:17:233PM | Plasma | Ok | |
| 27 | 05:07:10:667PM | Plasma | Ok | |