| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Steve Wukitch |
| Physics operator(s): | Joseph Snipes |
| Engineering operator(s): | Frank Silva,Bill Cochran,Vinny Bertolino |
| Engineering Operator Run Comment |
| mp150a silva cochran bertolino wukitch snipes |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:18:040PM |
| Author: To Be Determined |
****980212****980212****980212****980212****980212****980212****980212 MP150A D(He3) Heating at 8T Continuing MP150A (He3 Minority Heating at 8T) today (previous run in this campaign is 980206) with the explicit purpose of investigating RF absorption. We will begin with 5.4T discharges and step up to ~8T (fields are listed below). When raising the TF, ~7.1 T should be avoided because of H cyclotron resonance in the plasma edge could cause damage to the antenna. Hopefully we will obtain H-modes and do a small field scan. ------------------------------------------------------------------------------ Engineering setup for 980212: Two hours of ECDC in deuterium before the run, if possible. Engineering setup as on 98021020, with TF under PLC control Gas setup - fill K-side with 20 PSI of D2, hybrid enable fill B-top with 6 PSI of D2, hybrid enable fill B-side-lower with 3 PSI of Ar, hybrid enable fill B-side-upper with 16 PSI of He3, hybrid enable If this plenum already contains Helium-3 in the range of 15-20 psi, no need to top off. AFTER FILLING THE PLENUM, DISCONNECT THE PLC FROM THE VALVE!!! The following gate valves should be enabled, assuming no vacuum problems: ECE Adjust cooling to minimize the cooling time between discharges. (It was reset after 980206007.) 1. Start with 5.4T fiducial discharges and step up with constant q 5.4T, 0.8 MA, nl_04~1.0, q95~4.5 -- evaluate machine performance 6.2T: 980206005 6.9T, 980206008 7.5T, 980206011 enable B-side upper 7.9T, 980206013 enable B-side upper 2. 7.9T scan [He3] from low to higher with RF power modulation. The concentrations will be: 25 msec @100 V w/ 35 V maintenance 15 msec (same maintenance) 35 msec (same maintenance) 50 msec (same maintenance) 75 msec (same maintenance) 100 msec (same maintenance) 200 msec (same maintenance) 300 msec (same maintenance) 3. Scan BT down at the best ion heating/absorbed power concentration. Keep q95 constant 8 T 7.6 7.3 4. Inject Li pellets with low, moderate, and high [He3] ----------------------------------------------------------------------- RF engineering ST1 PS1 ST2 PS2 5.4T, 0.8 MA, nl_04~1.0 605 405 2557 909 6.2T, 0.95 MA, nl_04~1.0 605 404 2557 922 6.9T, Ip=1.05 599 411 2470 1008 7.6T, 25 msec He3 puff 576 420 2419 985 ======================================================================= Summary: This run was significantly better than 980206, but plasma/RF performance is still wanting. A few H-modes were obtained, but did not develop steady state character nor particularly good quality. The physics run plan, however, was accomplished From the RF perspective, the optimum He3 gas puff for good central ion and electron heating via He3 minority heating was identified to by 15-35 msec. Central ion temperatures reached 4 keV and central Te at the top of the sawteeth reached 5 keV. The multiple H-mode transitions during the discharge make determining the total absorbed power difficult, but the absorbed power appears to be about ~60% (a factor of 2 improvement compared to last 980206). More detailed analysis is required to obtain an accurate number. By varying the He3 concentration, the split between minority and mode conversion heating was explored. It was hoped to obtain this data in H-mode, but the plasma was not cooperating. Lowering the toroidal field to move the D resonance and Shear Alfven resonance out of the plasma with a 15 msec He3 puff did not significantly improve total absorbed power. A more detailed analysis will be required to confirm this. Over the last few discharges, the density, current, and RF waveform were varied to explore their effects on obtaining H-modes. Lowering the density improved H-mode accessibility, but not the duration of the H-modes. A concentrated scan of density is needed to evaluate the optimum density to obtain H-mode at 7.9T. A current scan is also needed considering the greater success of 980212025 in obtaining H-modes. The impact of RF power and waveform on obtaining H-modes needs further investigation. The density rise associated with the RF turnon is mostly likely bad for the plasma and RF performance. Reducing the density rise by outgassing the antenna or turning it on more slowly may lead to better overall performance. ======================================================================= ST1 PS1 ST2 PS2 next shot: 5.4T, 0.8 MA, nl_04~1.0 605 405 2557 909 001 plasma EF/EDA 107 kJ, H~1.5 Ar puff good RF H/(H+D)~1.5% following plasma going diverted next shot: 6.2T, 0.95 MA, nl_04~1.0 605 404 2557 921 disable Ar 002 fizzle 003 plasma EDA 129 kJ, H~1.5 (approaches 2 before settling ~1.5) good RF -- better plasma performance than 980206005 next shot: 6.9T, Ip=1.05 MA 599 411 2470 1008 004 plasma L-mode good RF H/(H+D)~1.5% next shot: 7.6T, Ip~1.15 MA enable B-side upper 25 msec He3 puff @100 V w/ 35 V maintenance raise RF power and modulated 005 plasma L-mode maintenance voltage was 32 V no YAG data next shot: 7.9T, Ip~1.2 MA 006 plasma multiple EF Yag data good RF modulation 95 msec before going ELM-free next shot: enable Ar, repeat 582 421 2405 1002 007 plasma early disruption multiple H-mode next shot: raise X-point 008 plasma multiple H-mode #1 tripped early next shot: 15 msec He3 puff @100 V 586 416 2426 992 009 plasma multiple H-mode good RF next shot: 7 msec He3 puff 010 plasma short H-mode injection 0.49 sec next shot: repeat 011 plasma short H-mode toward end of RF pulse, dithering throughout no injection, good RF next shot: 35 msec He3 puff 012 plasma short H-mode (140 kJ) dithering good RF next shot: 50 msec He3 puff 013 plasma short H-modes good RF next shot: 75 msec He3 puff, lower target nl_04->.75 014 plasma some dithering nl_04->0.9 good RF, but no RF wave forms next shot: 100 msec He3 puff 015 plasma some dithering good RF next shot: 200 msec He3 puff 016 plasma weak dithering good modulation and GPC signals reflect direct electron heating next shot: 300 msec He3 puff He3 puff to 0.3 579 420 2404 995 017 plasma MC off-axis next shot: He3 puff is 15 msec and starts 0.45 sec raise BT to 8T 018 plasma dithering is back central Te and ion heating returned Bt=8.0T next shot: lower Bt to 7.7T raised power and changed the modulation 019 plasma short Elm-free, dithering Bt=7.7 T good RF next shot: lower Bt to 7.4T 576 416 2422 976 020 plasma multiple H-modes Bt=7.4 T next shot: back to 7.87T Li pellet @1.27 sec 586 416 2443 963 021 plasma multiple Elm-free H-modes Bt=7.87 T Prf~3.3 MW no pellet next shot: lower density to 0.6x10^20 589 413 2455 956 try pellet again 022 plasma multiple Elm-free H-modes pellet ~1.276 sec nl_04-> 0.65 next shot: raise density to 0.75x10^20 and Li pellet @0.53 023 plasma multiple Elm-free H-modes no pellet next shot: Ramp RF power 024 plasma multiple Elm-free H-modes RF ramp up has little effect 025 plasma multiple Elm-free Ip->1.0 MA no RF modulation H/(H+D) is slightly above 2% (Boivin) |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:36:59:490PM |
| Author: To Be Determined |
| ****980212****980212****980212****980212****980212****980212****980212 MP150A D(He3) Heating at 8T Session Leader: Steve Wukitch Physics Operator: Joseph Snipes Engineer in Charge: Frank Silva Continuing MP150A (He3 Minority Heating at 8T) today (previous run in this campaign is 980206) with the explicit purpose of investigating RF absorption. We will begin with 5.4T discharges and step up to ~8T (fields are listed below). When raising the TF, ~7.1 T should be avoided because of H cyclotron resonance in the plasma edge could cause damage to the antenna. Hopefully we will obtain H-modes and do a small field scan. Engineering setup for 980212: Two hours of ECDC in deuterium before the run, if possible. Engineering setup as on 98021020, with TF under PLC control Gas setup - fill K-side with 20 PSI of D2, hybrid enable fill B-top with 6 PSI of D2, hybrid enable fill B-side-lower with 3 PSI of Ar, hybrid enable fill B-side-upper with 16 PSI of He3, no hybrid enable This was quite a successful run with heating up to 8 T and 1.2 MA. Many short ELM-free H-modes were obtained. The density was kept purposely low and I suspect that better H-modes might be obtained at higher density to try to achieve EDA H-mode. But, the purpose of the run was not specifically to achieve H-mode. Future 8 T runs could concentrate on H-mode quality now that good heating has been achieved. The machine ran very well today with no power supply problems or other difficulties. At 8 T, cooling requires about 20 minutes between shots, so fewer shots were obtained than during a 5.3 T run. Still, there were 25 shots with 24 good plasmas and one fizzle. One unusual feature were incredibly high divertor neutral pressure compression ratios up to 1500, which suggest that the divertor and/or midplane gauges have some difficulties. Brian has suggested performing a high field calibration shot during a maintenance day. A calibration performed between shots today showed no changes in calibration. Shot 1: Load shot 980210020 but with TF under PLC control for a standard fiducial shot with RF. Note uses segment 4 and not segment 2. Good shot. ELMy H-mode the EDA. Shot 2: Copied shot 980206005 which also uses segment 4 and then reloaded 980212001 segment 1 to maintain startup. TF set to 176 kA = 6.2 T. Fizzle. Br took a jump at 0.002 sec and Bz is a little lower. Disabled Ar puff. Shot 3: Raised EF4 current by 15 A from -1330 A to -1315 A. Good shot at 6.2 T and Ip = 0.9 MA. EDA throughout the RF pulse. Shot 4: Raised TF to 195 kA = 6.9 T, Ip to 0.975 MA by copying segment 4 of 980206008 into segment 4. Decreased EF4 current to -1345 A since Bz had increased on the previous shot. L-mode with dithering. Shot 5: Raise TF to 215 kA = 7.6 T. Copied segment 4 of shot 980206011. Enabled B side upper He3 puff with 25 msec at 100 V starting at 0.45 sec then 35 V maintenance level until 1.2 sec. Ip raised to 1.13 MA. Shot 6: Raise TF to 224 kA = 7.9 T. Ip up to 1.16 MA programmed. Copied segment 4 of shot 980206013. Then, changed He3 B side upper maintenance level to 35 V. Good shot. Short ELM-free H-mode followed by dithering and some ELMy H-modes. Shot 7: Enable B side lower Ar puff at 0.3 sec for 15 msec. Disrupted at 1.025 sec. ELM-free and ELMy H-modes before a moly injection at 0.94 sec. Shot 8: Raised ZXL by 3 mm to -0.012 m to hopefully avoid Moly injections that lead to disruptions. Good shot. ELM-free and ELMy H-modes. Shot 9: Reduced B side upper He3 puff to 15 msec at 100 V still with 35 V maintenance level. Good shot. Short ELM-free then steady dithering. Shot 10:Decrease B side upper He3 puff to 7 msec at 100 V with 35 V maintenance. Good shot. Short ELM-free H-mode at end of RF pulse. Shot 11:Repeat. Good shot. Short ELM-free H-mode at end of RF pulse. Shot 12:Increase B side upper He3 puff to 35 msec at 100 V with 35 V maintenance. Good shot. Short ELM-free H-mode earlier in RF pulse, then dithers throughout the RF. Shot 13:Increase B side upper He3 puff to 50 msec at 100 V with 35 V maintenance. Good shot. Short ELM-free H-mode earlier in RF pulse, then dithers throughout the RF. Shot 14:Density lowered to nl04 = 7 x 10^19 m^-2. Increase He3 puff to 75 msec at 100 V with 35 V maintenance. Good shot. L-mode with a few dithers. Lost magnetics TRAQ2 data, so we also lost EFIT results. Shot 15:Increase He3 puff to 100 msec at 100 V with 35 V maintenance. Good shot. Dithering throughout the RF pulse. Shot 16:Increase He3 puff to 200 msec at 100 V with 35 V maintenance. Good shot. D alpha MHD oscillations at around 600 Hz with a few dithers. Shot 17:Increase He3 puff to 300 msec at 100 V starting at 0.3 sec with 35 V maintenance from 0.6 to 1.2 sec. Good shot. L-mode throughout. Shot 18:Decrease He3 puff to 15 msec at 100 V starting at 0.45 sec with 35 V maintenance to 1.2 sec. TF set to 228 kA = 8.0 T, Ip up to 1.18 MA programmed (1.2 MA out) to maintain q(95) = 4.5 . Good shot. A few dithers and some low frequency D alpha oscillations in L-mode. Shot 19:Lower TF to 219 kA = 7.7 T. Lower Ip to 1.145 MA. Change TF start time to -1.3 sec. Good shot. Dithering with a short ELM-free H-mode. Shot 20:Lower TF to 211 kA = 7.4 T. Lower Ip to 1.115 MA. Good shot with many short ELM-free H-modes. Shot 21:Return to TF = 224 kA = 7.87 T, Ip = 1.16 MA programmed. Enabled LPI pellet to be injected at 1.27 sec. TF start time returned to -1.4 sec. Good shot. In and out of ELM-free H-mode. Shot 22:Lower nl04 to 6 x 10^19 m^-2. Another attempt to get a Li pellet at 1.27 sec. Good shot. Numerous short ELM-free H-modes. Shot 23:Raise nl04 to 7.5 x 10^19 m^-2. Li pellet at 0.5 sec. Raised EF4 current to -1330 A since Bz was somewhat low at breakdown. Good shot. Disrupted at 1.41 sec in the rampdown. Numerous small ELM-free H-modes. Shot 24:Repeat with Li pellet injector turned off. Good shot. Numerous short ELM-free H-modes. Shot 25:Reduce Ip to 1.0 MA. Good shot. Numerous short ELM-free H-modes. |
| Session Leader Comments | |||
| Feb 12 1998 08:23:37:790AM | Steve Wukitch | MP150A D(He3) Heating at 8T Continuing MP150A (He3 Minority Heating at 8T) today (previous run in this campaign is 980206) with the explicit purpose of investigating RF absorption. We will begin with 5.4T discharges and step up to ~8T (fields are listed below). When raising the TF, ~7.1 T should be avoided because of H cyclotron resonance in the plasma edge could cause damage to the antenna. Hopefully we will obtain H-modes and do a small field scan. ------------------------------------------------------------------------------ Engineering setup for 980212: Two hours of ECDC in deuterium before the run, if possible. Engineering setup as on 98021020, with TF under PLC control Gas setup - fill K-side with 20 PSI of D2, hybrid enable fill B-top with 6 PSI of D2, hybrid enable fill B-side-lower with 3 PSI of Ar, hybrid enable fill B-side-upper with 16 PSI of He3, hybrid enable If this plenum already contains Helium-3 in the range of 15-20 psi, no need to top off. AFTER FILLING THE PLENUM, DISCONNECT THE PLC FROM THE VALVE!!! The following gate valves should be enabled, assuming no vacuum problems: ECE Adjust cooling to minimize the cooling time between discharges. (It was reset after 980206007.) | |
| Feb 12 1998 08:24:13:830AM | Steve Wukitch | 1. Start with 5.4T fiducial discharges and step up with constant q 5.4T, 0.8 MA, nl_04~1.0, q95~4.5 -- evaluate machine performance 6.2T: 980206005 6.9T, 980206008 7.5T, 980206011 enable B-side upper 7.9T, 980206013 enable B-side upper 2. 7.9T scan [He3] from low to higher with RF power modulation. The concentrations will be: 25 msec @100 V w/ 35 V maintenance 12 msec (same maintenance) 35 msec (same maintenance) 50 msec (same maintenance) 75 msec (same maintenance) 100 msec (same maintenance) 200 msec (same maintenance) 300 msec (same maintenance) 3. Scan BT down at the best ion heating/absorbed power concentration. Keep q95 constant 8 T 7.6 7.3 4. Inject Li pellets with low, moderate, and high [He3] | |
| Feb 12 1998 08:36:20:000AM | 980212001 | Steve Wukitch | 001 plasma EF/EDA H~1.5 Ar puff good RF next shot: 6.2T, 0.95 MA, nl_04~1.0 605 404 2557 921 disable Ar |
| Feb 12 1998 08:48:32:870AM | 980212002 | Steve Wukitch | 002 fizzle |
| Feb 12 1998 09:01:56:860AM | 980212003 | Steve Wukitch | 003 plasma EDA 129 kJ, H~1.5 (approaches 2 before settling ~1.5) good RF next shot: 6.9T, Ip=1.05 MA 599 411 2470 1008 |
| Feb 12 1998 09:15:52:700AM | 980212004 | Steve Wukitch | 004 plasma L-mode good RF next shot: 7.6T, Ip~1.15 MA enable B-side upper 25 msec He3 puff @100 V w/ 35 V maintenance |
| Feb 12 1998 09:50:50:200AM | 980212005 | Steve Wukitch | 005 plasma L-mode He3 puff (25 msec w/35 V maintenance) no YAG data next shot: 7.9T, Ip~1.2 MA |
| Feb 12 1998 10:03:18:280AM | 980212006 | Steve Wukitch | 006 plasma multiple EF Yag data good RF modulation next shot: enable Ar, repeat 582 421 2405 1002 |
| Feb 12 1998 10:44:26:630AM | 980212007 | Steve Wukitch | 007 plasma early disruption multiple H-mode |
| Feb 12 1998 10:44:56:880AM | 980212008 | Steve Wukitch | 008 plasma multiple H-mode #1 tripped early but recovered well next shot: 15 msec He3 puff @100 V |
| Feb 12 1998 11:33:14:640AM | 980212009 | Steve Wukitch | 009 plasma multiple H-mode good RF next shot: 7 msec He3 puff |
| Feb 12 1998 11:33:34:920AM | 980212010 | Steve Wukitch | 010 plasma short H-mode injection 0.49 sec next shot: repeat |
| Feb 12 1998 11:54:09:480AM | 980212011 | Steve Wukitch | 011 plasma short H-mode toward end of RF pulse, dithering throughout no injection, good RF next shot: 35 msec He3 puff |
| Feb 12 1998 12:50:38:500PM | 980212012 | Steve Wukitch | 012 plasma short H-mode (140 kJ) dithering good RF next shot: 50 msec He3 puff |
| Feb 12 1998 12:51:15:570PM | 980212013 | Steve Wukitch | 013 plasma short H-modes good RF next shot: 75 msec He3 puff, lower target nl_04->.75 |
| Feb 12 1998 01:00:36:330PM | 980212014 | Steve Wukitch | 014 plasma some dithering nl_04->0.9 good RF next shot: 100 msec He3 puff |
| Feb 12 1998 01:34:20:850PM | 980212015 | Steve Wukitch | 015 plasma some dithering good RF next shot: 200 msec He3 puff |
| Feb 12 1998 02:27:59:980PM | 980212017 | Steve Wukitch | 017 plasma MC off-axis next shot: He3 puff is 15 msec and starts 0.45 sec raise BT to 8T |
| Feb 12 1998 03:02:13:240PM | 980212018 | Steve Wukitch | 018 plasma dithering is back central Te and ion heating returned Bt=8.0T next shot: lower Bt to 7.7T raised power and changed the modulation |
| Feb 12 1998 03:45:05:100PM | 980212019 | Steve Wukitch | next shot: lower Bt to 7.7T raised power and changed the modulation 019 plasma short Elm-free, dithering Bt=7.7 T good RF |
| Feb 12 1998 03:45:35:670PM | 980212020 | Steve Wukitch | 020 plasma multiple H-modes Bt=7.4 T next shot: back to 7.87T Li pellet @1.27 sec |
| Feb 12 1998 03:45:54:480PM | 980212021 | Steve Wukitch | 021 plasma multiple Elm-free H-modes Bt=7.87 T Prf~3.3 MW no pellet next shot: lower density to 0.6x10^20 589 413 2455 956 try pellet again |
| Feb 12 1998 06:21:05:780PM | 980212022 | Steve Wukitch | 022 plasma multiple Elm-free H-modes pellet ~1.276 sec nl_04-> 0.65 next shot: raise density to 0.75x10^20 and Li pellet @0.53 |
| Feb 12 1998 06:22:45:910PM | 980212023 | Steve Wukitch | 023 plasma multiple Elm-free H-modes no pellet next shot: Ramp RF power |
| Feb 12 1998 06:23:04:670PM | 980212024 | Steve Wukitch | 024 plasma multiple Elm-free H-modes RF ramp up has little effect |
| Feb 12 1998 06:23:19:510PM | 980212025 | Steve Wukitch | 025 plasma multiple Elm-free Ip->1.0 MA no RF modulation |
| Physics Operator Comments | |||
| Feb 12 1998 08:10:26:090AM | Joseph Snipes | MP150A D(He3) Heating at 8T Continuing MP150A (He3 Minority Heating at 8T) today (previous run in this campaign is 980206) with the explicit purpose of investigating RF absorption. We will begin with 5.4T discharges and step up to ~8T (fields are listed below). When raising the TF, ~7.1 T should be avoided because of H cyclotron resonance in the plasma edge could cause damage to the antenna. Hopefully we will obtain H-modes and do a small field scan. | |
| Feb 12 1998 08:12:36:470AM | Joseph Snipes | 1. Start with 5.4T fiducial discharges and step up with constant q 5.4T, 0.8 MA, nl_04~1.0, q95~4.5 -- evaluate machine performance 6.2T: 980206005 6.9T, 980206008 7.5T, 980206011 enable B-side upper 7.9T, 980206013 enable B-side upper | |
| Feb 12 1998 08:13:39:770AM | Joseph Snipes | 2. 7.9T scan [He3] from low to higher with RF power modulation. The concentrations will be: 25 msec @100 V w/ 35 V maintenance 12 msec (same maintenance) 35 msec (same maintenance) 50 msec (same maintenance) 75 msec (same maintenance) 100 msec (same maintenance) 200 msec (same maintenance) 300 msec (same maintenance) | |
| Feb 12 1998 08:14:36:600AM | Joseph Snipes | 3. Scan BT down at the best ion heating/absorbed power concentration. Keep q95 constant 8 T 7.6 7.3 4. Inject Li pellets with low, moderate, and high [He3] RF engineering ST1 PS1 ST2 PS2 5.4T, 0.8 MA, nl_04~1.0 605 405 2557 909 6.2T, 0.95 MA, nl_04~1.0 605 404 2557 922 6.9T, Ip=1.05 599 411 2470 1008 7.6T, 25 msec He3 puff 576 420 2419 985 | |
| Feb 12 1998 10:01:28:700AM | Joseph Snipes | Engineering setup for 980212: Two hours of ECDC in deuterium before the run, if possible. Engineering setup as on 98021020, with TF under PLC control Gas setup - fill K-side with 20 PSI of D2, hybrid enable fill B-top with 6 PSI of D2, hybrid enable fill B-side-lower with 3 PSI of Ar, hybrid enable fill B-side-upper with 16 PSI of He3, no hybrid enable | |
| Feb 12 1998 08:39:36:560AM | 980212001 | Joseph Snipes | Shot 1: Load shot 980210020 but with TF under PLC control for a standard fiducial shot with RF. Note uses segment 4 and not segment 2. Good shot. ELMy H-mode the EDA. |
| Feb 12 1998 08:52:22:110AM | 980212002 | Joseph Snipes | Shot 2: Copied shot 980206005 which also uses segment 4 and then reloaded 980212001 segment 1 to maintain startup. Fizzle. Br took a jump at 0.002 sec and Bz is a little lower. |
| Feb 12 1998 09:09:37:410AM | 980212003 | Joseph Snipes | Shot 3: Raised EF4 current by 15 A from -1330 A to -1315 A. Good shot at 6.2 T and Ip = 0.9 MA. EDA throughout the RF pulse. |
| Feb 12 1998 09:23:45:850AM | 980212004 | Joseph Snipes | Shot 4: Raised TF to 195 kA = 6.9 T, Ip to 0.975 MA by copying segment 4 of 980206008 into segment 4. Decreased EF4 current to -1345 A since Bz had increased on the previous shot. L-mode with dithering in ohmic phase and during the low power RF phase, but not during the high power RF phase. |
| Feb 12 1998 01:36:57:840PM | 980212005 | Joseph Snipes | Shot 5: Raise TF to 215 kA = 7.6 T. Enabled B side upper He3 puff with 25 msec at 100 V starting at 0.45 sec then 35 V maintenance level until 1.2 sec. Ip raised to 1.13 MA. Good shot. L-mode. Some dithering in the ohmic phase. |
| Feb 12 1998 10:38:23:710AM | 980212006 | Joseph Snipes | Shot 6: Raise TF to 224 kA = 7.9 T. Ip up to 1.16 MA programmed. Copied segment 4 of shot 980206013. Then, changed He3 B side upper maintenance level to 35 V. Good shot. Short ELM-free H-mode followed by dithering and some ELMy H-modes. |
| Feb 12 1998 10:38:45:450AM | 980212007 | Joseph Snipes | Shot 7: Enable B side lower Ar puff at 0.3 sec for 15 msec. Disrupted at 1.025 sec. ELM-free and ELMy H-modes before a moly injection at 0.94 sec. |
| Feb 12 1998 10:40:24:540AM | 980212008 | Joseph Snipes | Shot 8: Raised ZXL by 3 mm to -0.012 m to hopefully avoid Moly injections that lead to disruptions. Good shot. ELM-free and ELMy H-modes. |
| Feb 12 1998 11:11:59:710AM | 980212009 | Joseph Snipes | Shot 9: Reduced B side upper He3 puff to 15 msec at 100 V still with 35 V maintenance level. Good shot. Short ELM-free then steady dithering. |
| Feb 12 1998 11:50:54:090AM | 980212010 | Joseph Snipes | Shot 10:Decrease B side upper He3 puff to 7 msec at 100 V with 35 V maintenance. Good shot. Short ELM-free H-mode at end of RF pulse. |
| Feb 12 1998 12:09:53:470PM | 980212011 | Joseph Snipes | Shot 11:Repeat. Good shot. Short ELM-free H-mode at end of RF pulse. |
| Feb 12 1998 12:12:20:880PM | 980212012 | Joseph Snipes | Shot 12:Increase B side upper He3 puff to 35 msec at 100 V with 35 V maintenance. Good shot. Short ELM-free H-mode earlier in RF pulse, then dithers throughout the RF. |
| Feb 12 1998 01:04:14:600PM | 980212013 | Joseph Snipes | Shot 13:Increase B side upper He3 puff to 50 msec at 100 V with 35 V maintenance. Good shot. Short ELM-free H-mode earlier in RF pulse, then dithers throughout the RF. |
| Feb 12 1998 03:42:26:630PM | 980212014 | Joseph Snipes | Shot 14:Density lowered to nl04 = 7 x 10^19 m^-2. Increase He3 puff to 75 msec at 100 V with 35 V maintenance. Good shot. L-mode with a few dithers. Lost magnetics TRAQ2 data, so we also lost EFIT results. |
| Feb 12 1998 01:33:16:540PM | 980212015 | Joseph Snipes | Shot 15:Increase He3 puff to 100 msec at 100 V with 35 V maintenance. Good shot. Dithering throughout the RF pulse. |
| Feb 12 1998 01:48:51:050PM | 980212016 | Joseph Snipes | Shot 16:Increase He3 puff to 200 msec at 100 V with 35 V maintenance. Good shot. D alpha MHD oscillations at around 600 Hz with a few dithers. |
| Feb 12 1998 02:36:51:250PM | 980212017 | Joseph Snipes | Shot 17:Increase He3 puff to 300 msec at 100 V starting at 0.3 sec with 35 V maintenance from 0.6 to 1.2 sec. Good shot. L-mode throughout. |
| Feb 12 1998 02:37:05:380PM | 980212018 | Joseph Snipes | Shot 18:Decrease He3 puff to 15 msec at 100 V starting at 0.45 sec with 35 V maintenance to 1.2 sec. TF set to 228 kA = 8.0 T, Ip up to 1.18 MA programmed (1.2 MA out) to maintain q(95) = 4.5 . Good shot. A few dithers and some low frequency D alpha oscillations in L-mode. |
| Feb 12 1998 03:07:12:720PM | 980212019 | Joseph Snipes | Shot 19:Lower TF to 219 kA = 7.7 T. Lower Ip to 1.145 MA. Change TF start time to -1.3 sec. Good shot. Dithering with a short ELM-free H-mode. |
| Feb 12 1998 03:20:04:000PM | 980212020 | Joseph Snipes | Shot 20:Lower TF to 211 kA = 7.4 T. Lower Ip to 1.115 MA. Good shot with many short ELM-free H-modes. |
| Feb 12 1998 03:43:51:030PM | 980212021 | Joseph Snipes | Shot 21:Return to TF = 224 kA = 7.87 T, Ip = 1.16 MA programmed. Enabled LPI pellet to be injected at 1.27 sec. TF start time returned to -1.4 sec. Good shot. In and out of ELM-free H-mode. |
| Feb 12 1998 04:12:31:440PM | 980212022 | Joseph Snipes | Shot 22:Lower nl04 to 6 x 10^19 m^-2. Another attempt to get a Li pellet at 1.27 sec. Good shot. Numerous short ELM-free H-modes. |
| Feb 12 1998 04:29:45:030PM | 980212023 | Joseph Snipes | Shot 23:Raise nl04 to 7.5 x 10^19 m^-2. Li pellet at 0.5 sec. Raised EF4 current to -1330 A since Bz was somewhat low at breakdown. Disrupted at 1.41 sec in the rampdown. Numerous small ELM-free H-modes. |
| Feb 12 1998 04:41:00:360PM | 980212024 | Joseph Snipes | Shot 24:Repeat with Li pellet injector turned off. Good shot. Numerous short ELM-free H-modes. |
| Feb 12 1998 05:00:54:890PM | 980212025 | Joseph Snipes | Shot 25:Reduce Ip to 1.0 MA. Good shot. Numerous short ELM-free H-modes. |
| Feb 12 1998 05:11:47:910PM | 980212025 | Joseph Snipes | This was quite a successful run with heating up to 8 T and 1.2 MA. Many short ELM-free H-modes were obtained. The density was kept purposely low and I suspect that better H-modes might be obtained at higher density to try to achieve EDA H-mode. But, the purpose of the run was not specifically to achieve H-mode. Future 8 T runs could concentrate on H-mode quality now that good heating has been achieved. |
| Feb 12 1998 05:12:03:480PM | 980212025 | Joseph Snipes | The machine ran very well today with no power supply problems or other difficulties. At 8 T, cooling requires about 20 minutes between shots, so fewer shots were obtained than during a 5.3 T run. Still, there were 25 shots with 24 good plasmas and one fizzle. One unusual feature were incredibly high divertor neutral pressure compression ratios up to 1500, which suggest that the divertor and/or midplane gauges have some difficulties. Brian has suggested performing a high field calibration shot during a maintenance day. A calibration performed between shots today showed no changes in calibration. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:23:08:040AM | Plasma | Ok | no faults/plasma 156KA |
| 2 | 08:40:24:570AM | Plasma | Ok | tf 176kamps,plc,fizzle |
| 3 | 08:51:17:880AM | Plasma | Ok | no faults/plasma 176KA |
| 4 | 09:08:04:150AM | Plasma | Ok | no faults/plasma 196KA |
| 5 | 09:28:16:270AM | Plasma | Ok | no faults/plasma 215KA |
| 6 | 09:49:35:360AM | Plasma | Ok | plasma tf 224kamps plc |
| 7 | 10:14:15:510AM | Plasma | Ok | no faults |
| 8 | 10:35:49:430AM | Plasma | Ok | |
| 9 | 10:58:18:560AM | Plasma | Ok | |
| 10 | 11:23:32:510AM | Plasma | Ok | |
| 11 | 11:44:14:150AM | Plasma | Ok | |
| 12 | 12:06:51:410PM | Plasma | Ok | |
| 13 | 12:28:34:160PM | Plasma | Ok | |
| 14 | 12:52:48:970PM | Plasma | Ok | |
| 15 | 01:17:02:810PM | Plasma | Ok | |
| 16 | 01:40:11:620PM | Plasma | Ok | |
| 17 | 02:03:46:520PM | Plasma | Ok | |
| 18 | 02:30:58:810PM | Plasma | Ok | |
| 19 | 02:52:03:370PM | Plasma | Ok | |
| 20 | 03:12:06:570PM | Plasma | Ok | |
| 21 | 03:32:08:210PM | Plasma | Ok | |
| 22 | 03:53:18:380PM | Plasma | Ok | |
| 23 | 04:14:15:790PM | Plasma | Ok | |
| 24 | 04:35:46:510PM | Plasma | Ok | |
| 25 | 04:56:47:700PM | Plasma | Ok | |