| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Ian Hutchinson |
| Physics operator(s): | Robert Granetz |
| Engineering operator(s): | Bill Cochran,Gary Dekow,Frank Silva |
| Engineering Operator Run Comment |
| MP#199 |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:22:447PM |
| Author: To Be Determined |
| Session Leader summary 991104 Upper X-point H-modes MP 199 PO Granetz, SL Hutch. This run achieved upper-x-point H-modes with abnormal B direction, a first. Triangularity scans of the upper x-point from 0.6 to 0.36 were performed. Several operational problems with EF2 power supplies were encountered. The gussets did not seem to be a problem. The H-modes were very impurity dominated, ELM-free with rapid accumulation. It is not completely clear why, although the machine has not been boronized for a while. The RF was limited to about 1.3MW because we only had transmitter 1 with the 8973 tube. There are signs that the trends on the x-ray pedestal widths, wider at higher triangularity, are confirmed in the absence of significant changes in the divertor baffling (because of being diverted at the top). This will need further analysis, but indications are that we will find that it really is plasma shape, not divertor effects. EDA H-modes were not achieved, therefore the original intention to try to explore EDA threshold was not achieved. Three densities were run, but with the plasma conditions so poor, it is not clear what that proves. Plasma rotation measurements verify that the directions of the flows have all reversed -- a useful confirmation. Useful data was also obtained on the top x-ray array. Signal was observed, but no clear pedestal even though the midplane array sees a standard pedestal. In summary: a useful start on abnormal-field H-modes, but the specific aims of the MP were not achieved. |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:37:09:960PM |
| Author: To Be Determined |
| Physics operator summary for run 991104: MP 199 -- Upper x-point H-modes with reversed Bt SL: I. Hutchinson PO: R. Granetz EO: F. Silva/G. Dekow/B. Cochran Summary: Both the tokamak and the #1 ICRF transmitter worked very well today. We successfully did dynamic scans of the triangularity, and had plenty of ELMfree H-modes over a range of densities, but no EDA H-modes. The xray pedestal (outboard) did not show any consistent change with triangularity, indicating that we weren't even close to the ELMfree/EDA transition. Because of the x-point scanning, we had a number of shots in which EF2U reaches zero early in the shot (and subsequently turns off). This had a negative impact on equilibrium control for the remainder of the shot. The solution is to increase EF2_BY_EF4. Scorecard: 20 plasmas 4 fizzles 0 duds (0 due to lack of one or more power supplies) 0 test 1 aborted ---------- 25 total ------------------------------------------------------------------------------- Engineering setup for Thursday, 991104: Run will begin at 09:00 and end at 17:00 2 hours ECDC in D2 prior to the run, stopping 1 hour before run. Power system setup as on 991103023, except increase the limit on EF4 from 8.0 to 8.5 kA. Note: Fizzle detector should be on from t=0.08 to 1.7 s; short delay for TF 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 2 psi of Ne Hybrid DISABLED fill C-side with 30 psi of D2 Hybrid enabled leave J-bottom as is (pumped out) Hybrid DISABLED The following gate valves should be enabled, assuming no vacuum problems: ECE, VUV ------------------------------------------------------------------------------- Physics operator's setup for Thursday, 991104: MP 199 -- Upper x-point H-modes with reversed Bt Session leader: I. Hutchinson Physics operator: R. Granetz Load shot 991103014, and Increase PLC limit on EF4 from 8.0 to 8.5 kA, Enable segment 3, turn off segment 2, Set target density to nl_04=0.7e20 m-2 in segments 3 and 4, Confirm that Ip=1.0 MA in both segments 3 and 4, May want to shorten flattop to t=1.2 s, but still need post-shot Bt flattop, Disable B-side-upper (neon) valve for the first shot. We may turn it on later Disable B-side-lower (Ar) valve for the first shot. We will turn it on later, Copy offset in RCUR from segment 2 into segments 3 and 4, Copy offset in CLEARIN from segment 2 into segments 3 and 4, Copy (paste) CLEARIN demand programming from segment 2 into segments 3 & 4, Copy (paste) ZCUR demand programming from segment 2 into segments 3 & 4, AND then flip it's polarity in both segments 3 & 4 Segment 3 is an upper X-point in reversed field, with constant X-point location Segment 4 is identical, except that the upper and lower triangularities are scanned during the shot by sweeping RXU and RXL. ------------------------------------------------------------------------------- Note: 2 hours of ECDC in D2 were done just prior to this run. Hybrid coldstart done; no errors found Loaded 991103014 and executed all the items on the preceding checklist An error occurred when loading into model. EF2U & L parameters in the STRIKEPSI controller exceeded the permissible value. Steve Wolfe had me change the time constant from 9.0 to 5.9 s, which fixed the problem. (Button sequence: bring up STRIKEPSI wire, hit "Controller" button, hit "Time Constant" button, change value to 5.9, and "OK" all windows back to the main display.) Also changed the direction of RXU and RXL sweeps in segment 4 (now goes from low to high elongation). Ian decided that the Ip flattop did not have to be shortened. Also shortened B-side-upper puff from 100 to 50 ms (neon), although the valve is not enabled for the beginning of the run. Shot 01 -- Aborted. Problem with shot cycle. There was a Type-I fault in the TF during the CHECK state. Shot 02 -- Plasma. Hard disruption at t=0.33 s. Next shot: flip ZXU and ZXL waveforms in segments 3 & 4, and turn off STRIKEPSI in segments 3 & 4, and turn up the ZXU gain in segments 3 & 4. Shot 03 -- Plasma. Upper X-point. 1 MA. Disrupted in early rampdown. Next shot: reduce CLEARIN by 3 mm and increase RCUR by 2 mm to reduce both the inner and outer gaps. Have RF turn on from t=0.6 to 1.1 s. Start Ip rampdown at 1.3 s instead of 1.5 s. All changes were made in both segments 3 & 4. Shot 04 -- Fizzle. Bz0, Br0, and fill pressure look identical to the previous shot. Next shot: no changes. Shot 05 -- Fizzle. Next shot: increase Bz0 by increasing IC_EF4 from +1390 to +1405 A. Shot 06 -- Plasma. Good shot. 1 MA, upper X-point. Ramps all the way down. Almost got into vertical stability problem midway through rampdown. Outer gap is now 11-12 mm (ok for RF). Prf=0.9 MW. No H-modes. Good clearance to gussets. Next shot: Do low-to-high triangularity ramp by switching to segment 4. Also increase EF2_BY_EF4 to 2500 during the rampdown (to try and keep EF2's from going to zero). Shot 07 -- Plasma. Good shot. 1 MA, upper X-point. Prf=1.3 MW. No H-modes. Upper and lower triangularity both scanned by about +0.2. Next shot: increase both min and max of upper triangularity scan (RXU), and also play with ZXU waveform to try and keep q more constant. Shot 08 -- Plasma. Good shot. 1 MA, upper X-point. Prf=1.3 MW. No H-modes. Upper and lower triangularity both scanned. Upper triangularity scanned more than the previous shot. qpsi is still not well- controlled. Next shot: reduce Btor from 5.4 to 5.0 T in segment 4 (to enhance changes of getting an H-mode). Also reduce the early part of the RXU scan (i.e. start at slightly higher upper triangularity). Shot 09 -- Plasma. Good shot. 1 MA, upper X-point. Prf=1.3 MW. Got H-modes! Upper and lower triangularity both scanned. Next shot: same, except change polarity of the Bt waggle (for ECE). (This has been at t=1.000-1.115 s from the first shot.) Shot 10 -- Plasma. Good shot. 1 MA, upper X-point. Prf=1.4-1.5 MW. Upper and lower triangularity both scanned. Qpsi is much better. nl_04=0.7e20 m-2. Substantial Prad and core x-ray emission...lots of molybdenum? Next shot: increase density to nl_04=1.0e20 m-2. Shot 11 -- Plasma. Good shot. 1 MA, upper X-point. Prf=1.4-1.5 MW. Upper and lower triangularity both scanned. Large Prad and core x-ray emission. Lousy H-mode compared to previous 2 shots. Next shot: change scan programming on RXU and RXL. Shot 12 -- Plasma. Good shot. 1 MA, upper X-point. Prf=1.4-1.5 MW. Two strong (but short) H-modes. Next shot: no PCS changes. Let RF improve tuning. John will fire CaF2 at t=0.8 s. Shot 13 -- Plasma. Good shot. 1 MA, upper X-point. Prf=1.2-1.3 MW. Three strong (but short) H-modes. Next shot: increase early density, change Btor back to 5.4 T, and add on a post-plasma TF flattop at 50 kA for resistance measurements (Somehow this was missing from segments 3 & 4.) Change CaF2 injection time to t=0.9 s. Shot 14 -- Plasma. Good shot. 1 MA, upper X-point. Prf=1.2-1.3 MW. Two strong (and slightly longer) ELMfree H-modes. Bt=5.4 T, and the post-plasma flattop is indeed there. Next shot: change RXU and RXL waveforms to increase the scan range, and to start somewhat earlier. There is a delay to work on a problem with the cooling water pressure for the RF transmitter. Shot 15 -- Plasma. Hard 1 MA disruption at t=0.79 s. Was it our X-point sweep programming? PF breaker pulled at the disruption. It seems that OH2L crowbarred and caused the disruption. Next shot: more changes to RXU and RXL waveforms. Shot 16 -- Plasma. Good shot. 1 MA, upper X-point. Prf=1.4 MW. Short H-mode. Good triangularity scan. Next shot: more changes to RXU and RXL waveforms late in the discharge. Lower ZXU by 1 cm around t=0.7 s (at farthest in RXU) so LCFS comes into view of top xray array (requested by Thomas), and start RF at 0.6 s so that plasma may be in H-mode at t=0.7 s. Also move CaF2 injection to t=0.7 s. Shot 17 -- Plasma. Good shot. 1 MA, upper X-point. Prf=1.2 MW. Short H-mode. Good triangularity scan. Two ELMfree H-modes, the first starting at t=0.7 s. Next shot: reverse polarity of the Bt waggle, and increase density to nl_04=1.2e20 m-2. Also tweak ZXU and RXU some more at t=0.7 s, again to try and get them with the field of view of the top xray array. Shot 18 -- Plasma. Hard disruption at t=1.19 s. I_halo_U=188 kA. Guess it doesn't like the higher density. EF2U hit zero early on, and that's the end of our shape control. Next shot: reduce Ip to 0.8 MA. Shot 19 -- Fizzle. Next shot: increase Br0 by 0.5 mT Shot 20 -- Plasma. Good shot. Ip=0.8 MA. RF faulted early. EF2U still hits zero and turns off early. No H-modes. Next shot: lower nl_04 to 0.9e20 m-2. Also add 5 amps to IC_EF4 to increase Bz0 a tad. Shot 21 -- Plasma. Disrupted at t=1.25 s. I_halo_U=110 kA. Prf=1 MW. Several short H-modes. EF2U still zeroed early, which degrades the triangularity scan somewhat. Next shot: remove the RXU and ZXU tweaks made before shot 18. I think these are what cause the EF2U problem. Shot 22 -- Plasma. Disrupted at t=1.38 s. I_halo_U=110 kA. Prf=1.0-1.4 MW. Several very short H-modes. EF2U still zeroes early. Next shot: increase EF2_BY_EF4 during early flattop. Also turn down EC_EF4 gain earlier. Shot 23 -- Fizzle. RF faulted out just before the shot anyway. Next shot: no changes. Shot 24 -- Plasma. Good shot. 0.8 MA, ramps all the way down. Prf=1.4 MW. Several short H-modes. Good triangularity ramp. Next shot: move Bt waggle earlier by 150 ms to get it in during the RF pulse. Also raise the density to nl_04=1.3e20 m-2. Shot 25 -- Plasma. Good shot. 0.8 MA, nl_04=1.3e20 m-2. Prf=1.4 MW. Best ELMfree H-mode of the day. Good triangularity scan. End of run. |
| Session Leader Comments | |||
| Nov 4 1999 10:55:49:623AM | 991104003 | Ian Hutchinson | First upper X-point (without strkpsi control). Gaps are a little large. No sweep or RF. No H-mode. Density nl04=.7e20. No gusset interaction out to 1.5s. Disruption in ramp-down appears to be a power supply problem, is certainly a control problem. |
| Nov 4 1999 11:35:19:763AM | 991104006 | Ian Hutchinson | Plasma ramps down. RF at .5 to .9MW shows some heating. nl04=.7e20 Gaps reduced to 1.5 left 1cm right. Still well clear of the gussets. No sign of H-mode. |
| Nov 4 1999 12:19:09:480PM | 991104007 | Ian Hutchinson | Triangularity scan from .40 to .56, qpsi from 3.2 to 3.7 RF ramps to 1.3MW. No H-mode. nl04 .7e20 |
| Nov 4 1999 12:20:29:903PM | 991104008 | Ian Hutchinson | Triangularity scans from .36 to .6. q_psi 3.1 to 3.7. Slightly too far out at about .7s seems to interact with gusset. A gas puff happens simultaneously. RF ramps to nearly 1.4MW but no H-mode. |
| Nov 4 1999 12:40:44:577PM | 991104009 | Ian Hutchinson | Triangularity scan .38 to .60, qpsi 3. to 3.5. B_t=5.07T Obtains a feeble H-mode from .72 to .87s. Rf about 1MW at that time. |
| Nov 4 1999 01:05:24:903PM | 991104010 | Ian Hutchinson | Substantial injection at .82s. Feeble H-mode again. Triangularity .38 to .6, q flatter: 3.0 to 3.3. |
| Nov 4 1999 01:16:52:500PM | 991104011 | Ian Hutchinson | nl04 1.e20. Big injection at .7s when the RF turns on (1.4MW) Immediate reduction in impurity when RF turns off. No discernable H-mode. |
| Nov 4 1999 01:36:21:170PM | 991104012 | Ian Hutchinson | Changed the triangularity to scan inward first .6 to .49. Got two clear elm-free H-modes, with strong accumulation. Clear edge rotation which is positive, 30-35 km/s. Sawteeth are not so clear but show signs of negative rotation during the H-phase. |
| Nov 4 1999 02:01:55:700PM | 991104013 | Ian Hutchinson | nl04 target 1.e20. Triang .62 to .5 Three elm-free H-modes, during which nl04 goes up to 1.7e20. Edge rotation up to +40km/s Some sawtooth propagation at about -40km/s |
| Nov 4 1999 02:18:52:123PM | 991104014 | Ian Hutchinson | Bt back to 5.4T. Triag .61 to .5 Elm-free H-mode still accumulating. Sawteeth not completely clear. Edge rotation apparently as high as 50km/s slowing. |
| Nov 4 1999 02:50:44:950PM | 991104015 | Ian Hutchinson | Changed the trinagularity sweep to early high to later low. Disrupts at .78s. Caused by EF2 zeroing because of the triangularity. |
| Nov 4 1999 03:22:59:827PM | 991104016 | Ian Hutchinson | Traingularity scans 0.6 to 0.4. H-mode at .87 to 1.02s. Still no EDA. |
| Nov 4 1999 03:47:20:873PM | 991104017 | Ian Hutchinson | RF starts at .6s. First H-mode starts at .7s. Hence we get an L-H at highest triangularity 0.58. Second H-mode is at much lower triangularity. No trophy on the sawteeth. |
| Nov 4 1999 04:05:00:483PM | 991104018 | Ian Hutchinson | EF2U current goes to zero at .65s and stays off. Disrupts at 1.19s with a weird shape. |
| Nov 4 1999 04:37:49:890PM | 991104020 | Ian Hutchinson | EF2u turns off again. But the plasma survives. No H-mode. |
| Nov 4 1999 05:04:48:013PM | 991104021 | Ian Hutchinson | EF2u switches off again. The plasma lasts till 1.2s. A little H-mode. |
| Nov 4 1999 06:09:16:153PM | 991104025 | Ian Hutchinson | A tolerably long-lived H-mode but still not EDA. |
| Physics Operator Comments | |||
| Nov 4 1999 09:53:50:420AM | Robert Granetz | Engineering setup for Thursday, 991104: Run will begin at 09:00 and end at 17:00 2 hours ECDC in D2 prior to the run, stopping 1 hour before run. Power system setup as on 991103023, except increase the limit on EF4 from 8.0 to 8.5 kA. Note: Fizzle detector should be on from t=0.08 to 1.7 s; short delay for TF 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 2 psi of Ne Hybrid DISABLED fill C-side with 30 psi of D2 Hybrid enabled leave J-bottom as is (pumped out) Hybrid DISABLED The following gate valves should be enabled, assuming no vacuum problems: ECE, VUV | |
| Nov 4 1999 09:54:22:030AM | Robert Granetz | Physics operator's setup for Thursday, 991104: MP 199 -- Upper x-point H-modes with reversed Bt Session leader: I. Hutchinson Physics operator: R. Granetz Load shot 991103014, and Increase PLC limit on EF4 from 8.0 to 8.5 kA, Enable segment 3, turn off segment 2, Set target density to nl_04=0.7e20 m-2 in segments 3 and 4, Confirm that Ip=1.0 MA in both segments 3 and 4, May want to shorten flattop to t=1.2 s, but still need post-shot Bt flattop, Disable B-side-upper (neon) valve for the first shot. We may turn it on later Disable B-side-lower (Ar) valve for the first shot. We will turn it on later, Copy offset in RCUR from segment 2 into segments 3 and 4, Copy offset in CLEARIN from segment 2 into segments 3 and 4, Copy (paste) CLEARIN demand programming from segment 2 into segments 3 & 4, Copy (paste) ZCUR demand programming from segment 2 into segments 3 & 4, AND then flip it's polarity in both segments 3 & 4 Segment 3 is an upper X-point in reversed field, with constant X-point location Segment 4 is identical, except that the upper and lower triangularities are scanned during the shot by sweeping RXU and RXL. | |
| Nov 4 1999 10:05:02:640AM | Robert Granetz | Note: 2 hours of ECDC in D2 were done just prior to this run. Hybrid coldstart done; no errors found Loaded 991103014 and executed all the items on the preceding checklist An error occurred when loading into model. EF2U & L parameters in the STRIKEPSI controller exceeded the permissible value. Steve Wolfe had me change the time constant from 9.0 to 5.9 s, which fixed the problem. (Button sequence: bring up STRIKEPSI wire, hit "Controller" button, hit "Time Constant" button, change value to 5.9, and "OK" all windows back to the main display.) Also changed the direction of RXU and RXL sweeps in segment 4 (now goes from low to high elongation). Ian decided that the Ip flattop did not have to be shortened. Also shortened B-side-upper puff from 100 to 50 ms (neon), although the valve is not enabled for the beginning of the run. | |
| Nov 4 1999 04:15:52:700PM | 991104001 | Robert Granetz | Shot 01 -- Aborted. Problem with shot cycle. There was a Type-I fault in the TF during the CHECK state. |
| Nov 4 1999 10:50:43:030AM | 991104002 | Robert Granetz | Shot 02 -- Plasma. Hard disruption at t=0.33 s. Next shot: flip ZXU and ZXL waveforms in segments 3 & 4, and turn off STRIKEPSI in segments 3 & 4, and turn up the ZXU gain in segments 3 & 4. |
| Nov 4 1999 11:04:10:683AM | 991104003 | Robert Granetz | Shot 03 -- Plasma. Upper X-point. 1 MA. Disrupted in early rampdown. Next shot: reduce CLEARIN by 3 mm and increase RCUR by 2 mm to reduce both the inner and outer gaps. Have RF turn on from t=0.6 to 1.1 s. Start Ip rampdown at 1.3 s instead of 1.5 s. All changes were made in both segments 3 & 4. |
| Nov 4 1999 11:00:33:653AM | 991104004 | Robert Granetz | Shot 04 -- Fizzle. Bz0, Br0, and fill pressure look identical to the previous shot. Next shot: no changes. |
| Nov 4 1999 11:13:12:280AM | 991104005 | Robert Granetz | Shot 05 -- Fizzle. Next shot: increase Bz0 by increasing IC_EF4 from +1390 to +1405 A. |
| Nov 4 1999 11:37:26:747AM | 991104006 | Robert Granetz | Shot 06 -- Plasma. Good shot. 1 MA, upper X-point. Ramps all the way down. Almost got into vertical stability problem midway through rampdown. Outer gap is now 11-12 mm (ok for RF). Prf=0.9 MW. No H-modes. Good clearance to gussets. Next shot: Do low-to-high triangularity ramp by switching to segment 4. Also increase EF2_BY_EF4 to 2500 during the rampdown (to try and keep EF2's from going to zero). |
| Nov 4 1999 11:57:15:000AM | 991104007 | Robert Granetz | Shot 07 -- Plasma. Good shot. 1 MA, upper X-point. Prf=1.3 MW. No H-modes. Upper and lower triangularity both scanned by about +0.2. Next shot: increase both min and max of upper triangularity scan (RXU), and also play with ZXU waveform to try and keep q more constant. |
| Nov 4 1999 12:22:23:170PM | 991104008 | Robert Granetz | Shot 08 -- Plasma. Good shot. 1 MA, upper X-point. Prf=1.3 MW. No H-modes. Upper and lower triangularity both scanned. Upper triangularity scanned more than the previous shot. qpsi is still not well- controlled. Next shot: reduce Btor from 5.4 to 5.0 T in segment 4 (to enhance changes of getting an H-mode). Also reduce the early part of the RXU scan (i.e. start at slightly higher upper triangularity). |
| Nov 4 1999 12:35:57:793PM | 991104009 | Robert Granetz | Shot 09 -- Plasma. Good shot. 1 MA, upper X-point. Prf=1.3 MW. Got H-modes! Upper and lower triangularity both scanned. Next shot: same, except change polarity of the Bt waggle (for ECE). (This has been at t=1.000-1.115 s from the first shot.) |
| Nov 4 1999 01:24:15:357PM | 991104009 | Robert Granetz | X-ray pedestal width (outboard) increases as the triangularity increases. |
| Nov 4 1999 12:58:54:937PM | 991104010 | Robert Granetz | Shot 10 -- Plasma. Good shot. 1 MA, upper X-point. Prf=1.4-1.5 MW. Upper and lower triangularity both scanned. Qpsi is much better. nl_04=0.7e20 m-2. Substantial Prad and core x-ray emission...lots of molybdenum? Next shot: increase density to nl_04=1.0e20 m-2. |
| Nov 4 1999 01:15:45:780PM | 991104011 | Robert Granetz | Shot 11 -- Plasma. Good shot. 1 MA, upper X-point. Prf=1.4-1.5 MW. Upper and lower triangularity both scanned. Large Prad and core x-ray emission. Lousy H-mode compared to previous 2 shots. Next shot: change scan programming on RXU and RXL. |
| Nov 4 1999 01:35:16:327PM | 991104012 | Robert Granetz | Shot 12 -- Plasma. Good shot. 1 MA, upper X-point. Prf=1.4-1.5 MW. Two strong (but short) H-modes. Next shot: no PCS changes. Let RF improve tuning. John will fire CaF2 at t=0.8 s. |
| Nov 4 1999 02:31:42:577PM | 991104013 | Robert Granetz | Shot 13 -- Plasma. Good shot. 1 MA, upper X-point. Prf=1.2-1.3 MW. Three strong (but short) H-modes. Next shot: increase early density, change Btor back to 5.4 T, and add on a post-plasma TF flattop at 50 kA for resistance measurements (Somehow this was missing from segments 3 & 4.) Change CaF2 injection time to t=0.9 s. |
| Nov 4 1999 02:17:06:903PM | 991104014 | Robert Granetz | Shot 14 -- Plasma. Good shot. 1 MA, upper X-point. Prf=1.2-1.3 MW. Two strong (and slightly longer) ELMfree H-modes. Bt=5.4 T, and the post-plasma flattop is indeed there. Next shot: change RXU and RXL waveforms to increase the scan range, and to start somewhat earlier. |
| Nov 4 1999 02:32:20:200PM | 991104014 | Robert Granetz | There is a delay to work on a problem with the cooling water pressure for the RF transmitter. |
| Nov 4 1999 02:57:24:653PM | 991104015 | Robert Granetz | Shot 15 -- Plasma. Hard 1 MA disruption at t=0.79 s. Was it our X-point sweep programming? PF breaker pulled at the disruption. It seems that OH2L crowbarred and caused the disruption. Next shot: more changes to RXU and RXL waveforms. |
| Nov 4 1999 03:26:46:890PM | 991104016 | Robert Granetz | Shot 16 -- Plasma. Good shot. 1 MA, upper X-point. Prf=1.4 MW. Short H-mode. Good triangularity scan. Next shot: more changes to RXU and RXL waveforms late in the discharge. Lower ZXU by 1 cm around t=0.7 s (at farthest in RXU) so LCFS comes into view of top xray array (requested by Thomas), and start RF at 0.6 s so that plasma may be in H-mode at t=0.7 s. Also move CaF2 injection to t=0.7 s. |
| Nov 4 1999 03:42:57:043PM | 991104017 | Robert Granetz | Shot 17 -- Plasma. Good shot. 1 MA, upper X-point. Prf=1.2 MW. Short H-mode. Good triangularity scan. Two ELMfree H-modes, the first starting at t=0.7 s. Next shot: reverse polarity of the Bt waggle, and increase density to nl_04=1.2e20 m-2. Also tweak ZXU and RXU some more at t=0.7 s, again to try and get them with the field of view of the top xray array. |
| Nov 4 1999 03:56:51:810PM | 991104018 | Robert Granetz | Shot 18 -- Plasma. Hard disruption at t=1.19 s. I_halo_U=188 kA. Guess it doesn't like the higher density. EF2U hit zero early on, and that's the end of our shape control. Next shot: reduce Ip to 0.8 MA. |
| Nov 4 1999 04:07:46:730PM | 991104019 | Robert Granetz | Shot 19 -- Fizzle. Next shot: increase Br0 by 0.5 mT |
| Nov 4 1999 04:30:34:047PM | 991104020 | Robert Granetz | Shot 20 -- Plasma. Good shot. Ip=0.8 MA. RF faulted early. EF2U still hits zero and turns off early. No H-modes. Next shot: lower nl_04 to 0.9e20 m-2. Also add 5 amps to IC_EF4 to increase Bz0 a tad. |
| Nov 4 1999 04:45:10:997PM | 991104021 | Robert Granetz | Shot 21 -- Plasma. Disrupted at t=1.25 s. I_halo_U=110 kA. Prf=1 MW. Several short H-modes. EF2U still zeroed early, which degrades the triangularity scan somewhat. Next shot: remove the RXU and ZXU tweaks made before shot 18. I think these are what cause the EF2U problem. |
| Nov 4 1999 05:10:00:140PM | 991104022 | Robert Granetz | Shot 22 -- Plasma. Disrupted at t=1.38 s. I_halo_U=110 kA. Prf=1.0-1.4 MW. Several very short H-modes. EF2U still zeroes early. Next shot: increase EF2_BY_EF4 during early flattop. Also turn down EC_EF4 gain earlier. |
| Nov 4 1999 05:27:53:653PM | 991104023 | Robert Granetz | Shot 23 -- Fizzle. RF faulted out just before the shot anyway. Next shot: no changes. |
| Nov 4 1999 05:45:46:077PM | 991104024 | Robert Granetz | Shot 24 -- Plasma. Good shot. 0.8 MA, ramps all the way down. Prf=1.4 MW. Several short H-modes. Good triangularity ramp. Next shot: move Bt waggle earlier by 150 ms to get it in during the RF pulse. Also raise the density to nl_04=1.3e20 m-2. |
| Nov 4 1999 06:14:23:153PM | 991104025 | Robert Granetz | Shot 25 -- Plasma. Good shot. 0.8 MA, nl_04=1.3e20 m-2. Prf=1.4 MW. Best ELMfree H-mode of the day. Good triangularity scan. End of run. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:55:18:530AM | Plasma | Bad | Type 1 fault on TF before shot all breakers open |
| 2 | 10:06:36:077AM | Plasma | Ok | no faults/disruption |
| 3 | 10:30:05:827AM | Plasma | Ok | no faults/plasma |
| 4 | 10:50:51:140AM | Plasma | Ok | no faults/ fizzel |
| 5 | 11:06:00:933AM | Plasma | Ok | no faults |
| 6 | 11:22:34:577AM | Plasma | Ok | (null) |
| 7 | 11:40:08:217AM | Plasma | Ok | (null) |
| 8 | 12:01:16:980PM | Plasma | Ok | (null) |
| 9 | 12:21:21:500PM | Plasma | Ok | (null) |
| 10 | 12:39:15:030PM | Plasma | Ok | (null) |
| 11 | 01:00:00:250PM | Plasma | Ok | (null) |
| 12 | 01:18:54:170PM | Plasma | Ok | (null) |
| 13 | 01:34:58:187PM | Plasma | Ok | (null) |
| 14 | 01:59:55:187PM | Plasma | Ok | (null) |
| 15 | 02:36:51:280PM | Plasma | Bad | oh2lower and oh1 commutation flt |
| 16 | 03:02:12:890PM | Plasma | Ok | (null) |
| 17 | 03:26:07:560PM | Plasma | Ok | (null) |
| 18 | 03:43:55:280PM | Plasma | Ok | (null) |
| 19 | 04:03:21:200PM | Plasma | Ok | (null) |
| 20 | 04:17:31:700PM | Plasma | Ok | (null) |
| 21 | 04:36:17:060PM | Plasma | Ok | (null) |
| 22 | 05:00:44:327PM | Plasma | Ok | (null) |
| 23 | 05:19:16:560PM | Plasma | Ok | (null) |
| 24 | 05:32:31:293PM | Plasma | Ok | (null) |
| 25 | 05:52:50:467PM | Plasma | Ok | (null) |