| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Amanda Hubbard,Amanda Hubbard |
| Physics operator(s): | Dmitri Mossessian |
| Engineering operator(s): | Bill Parkin,Bill Byford |
| Engineering Operator Run Comment |
| PO:Mossessian SL:Hubbard EO:Byford/Parkin Run Plan MP 287 |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:27:837PM |
| Author: To Be Determined |
| Physics Run summary for 1010726 A) MP 287, Asdex H-mode similarity experiment B) MP 137 L-H-L hysteresis Session Leader: Amanda Hubbard Physics Operator: Dmitri Mossessian RF Operators: S. Wukitch, Y. Lin Physics Run plan for 1010726, MP 287 Asdex H-mode similarity experiment Goal: To make high density, high power EDA H-modes in a shape identical to that in ASDEX-Upgrade 'Type II ELM' discharges. This regime, which was only recently obtained on AUG, appears rather similar to that obtained on C-Mod when power is increased into EDA H-modes. At reduced powers, AUG sometimes sees a 'quasi-coherent' mode. We would like to see if the same behaviour is observed on the two machines with the same dimensionless parameters. We will obtain edge profiles both at threshold and in the steady H-mode period. AUG will then try to match the dimensionless parameters (nu*,beta, rho*) of these discharges. Plan: 1)We will continue the plan starting from the shape and parameter development from 1010719 (see run summaries). Start from 1010719017, 5.3 T, 900 kA. Should do whatever ECDC minimizes the H/D ratio, which I presume means overnight in Deuterium. RF should use flat waveform, about 2.2 MW from D and E only. It is hoped that with lower H/D this shot will become more like EDA, rather than Type III ELMy. If conditions are moderately steady, measure pedestals, and fluctuations. Can also tune J-port at low power on these. If H-mode remains very ELM-free and transient, skip straight to 3) and 4). 2) Add power from J-port (70 MHz), at maximum available power. This will be off-axis, which is non-optimal, but should help to raise pedestal temperature. 3) 1-2 shots with ramped power, to get good data at LH threshold (D and E only) 4) Increase density, which hopefully will also improve access to EDA. A dimensionless match to the best AUG 'grassy ELM' shots would correspond to a line integrated density of 4.7e20, higher than our usual range. Increase starting density, and probably puff gas into EDA, to see how high we can get and still maintain a decent, steady H-mode (and couple enough power). ECE will probably be cut off, so good ETS data are essential. Again, use max available power without and with J-port. 5) Once the 'high density' H-mode has been characterized, use a slow power ramp to determine the corresponding threshold power and edge parameters. If we complete the experimental plan, or determine we are not likely to do so, go to **************************************************************************** Part B) L-H-L threshold experiment (which requires only 2 MW, D+E): Goal: Obtain full pedestal and power flux information during L-H-L hysteresis cycle, using RF power ramps. This will allow tests of possible functions of gradients as a function of input flux. Approach will be similar to 990915 (when we didn't have edge TS working fully). Plan: Start with 5.4 T, 800 kA plasma, shape and engineering as on 1010717, but constant Bt. Nel_04=1.0e20 m-2. Should have steady Ip flat-top by 0.4 secs or earlier, extending to 1.5 secs. RF power at 80 MHz (D + E). Ramp linearly UP, from 0-2.0 MW, 0.4-0.9 secs, FLAT 0.9-1.0 secs, and back DOWN 1.0-1.5 secs. This should get us comfortably into and out of a steady EDA H-mode. Once required data is achieved, raise density to 1.5e20m-2. Repeat with similar waveforms. If we don't get much above the L-H threshold, may want to increase max RF power slightly if possible. Reduce nel_04 to 0.7e20 m-2. Repeat RF ramps again. If time, extend density range still further. However, if we go much lower will probably run into ELM-free, non-steady H-modes with spontaneous transitions, while higher may require too much RF. *********************************************************************8** Results: The run got off to a slow and painful start, with simultaneous alternator, CAMAC and hybrid computer failures, probably due to the previous day's heat. At least they were solved in parallel, and after starting in earnest about noon the machine ran well. We completed parts 1-3 of the AUG similarity experiment. The machine conditions were much better than on 1010719, with H/D typically about 6-8%. From shot 12 on we used between-shot ECDC to keep it that way. Once again, we found that one does not get steady, EDA-type discharges at this shape, and also that RF coupling is much more difficult (the two things may be related). On some shots a weak quasi-coherent mode was seen on PCI, but it was not strong enough to cause large particle transport. The optimum density seemed to be nel=9.5e20 m-3; at higher targets the gas pressure increased substantially. H-mode density became steadier, but seemed to consist of bursts of higher transport, reminiscent of the typical behaviour with Type III ELMs and a cold edge, though the ELMs were not immediately obvious. (eg. shots 10,13). Lower density gave more ELM-free behaviour, sometimes with the QC mode visble (eg shots 5,11,12). RF had difficulty matching to the changing conditions and there were typically a number of trips in the 2 MW power at 80 MHz. On several occasions there were also injections from the upper part of the vessel and/or antennas, which didn't help with maintaining the H-modes. From shot 13 some off-axis power at 70 MHz was added. The best H-mode discharge of the run was shot 14, which had a total power of 3.8 MW, without trips. A single H-mode ws obtained which was not steady-state but had moderate and steady increases in density and radiation. This will be suitable for ASDEX-Upgrade to attempt to match. Shortly after the H-mode, however, a large injection caused a disruption; I suspect it will be difficult for the vessel to take high power levels at this shape. Given this, and limited time available, we completed this expt by takinga slow power ramp to get the threshold power and edge parameters at identical target conditons (shot 15). This will be suitable for AUG threshold comparisons. We did not attempt to push the density up in H-mode (4 and 5 of the run plan; this will have to await a future campaign). The run then switched to Part B, L-H-L hysteresis studies, ~4pm. Plasmas were 800 kA and of a fairly standard C-Mod shape. Initial target density was 9e19 m-2. All discharges gave very steady EDAs. Shot 16 had a slow power rampup. Shots 17-19 all used a programmed RF waveform from 0.4-2 MW, then back to 0. There were only a few RF glitches, at low power (near the H-L transitions). Plasmas stayed in H-mode down to very low RF power; there was typically a short period of type III ELMs before the back-transition. On shot 20 we attempted to repeat at a higher target density of 1.2 e20 m-3. However, this resulted in very high gas fill. RF had difficulty coupling due to the big change; it is unlikely there would have been an H-mode even at 2 MW. For the final discharge the density was instead lowered to 7e19m-3, which gave a nice EDA H-mode. Good edge TS data were obtained, which we will compare to previous results with the ECE and visible bremsstrahlung. The goal is to examine the hysteresis curve of input flux vs various gradients, such as grad T and grad P/n. This is being compared to predictions of various H-mode theories, in collaboration with Ben Carreras of ORNL. Results will be presented at the Transport Barrier workshop in September. A few more shots at different densities would of course be welcome! All in all, a pretty good run considering the difficult start and shortened time available. Thanks to all those engineers and others who got things working, and stayed late to complete it. Shot Details: ---------------------------------------------------------------------------- 1010726004 hubbard SESSION_LEADER Jul 26 2001 12:15:36:616PM . . . . . . . . . . . . . . . . . . . . Plasma. Due to lack of TCI feedback, we had VERY low density and neutral pressure. Not surprisingly, the H-Modes were ELM-free and had high pedestal temps, low ne. May be an interesting shot for low collisionality studies! ----------------------------------------------------------------------------- 1010726005 hubbard SESSION_LEADER Jul 26 2001 12:25:10:820PM . . . . . . . . . . . . . . . . . . . . This time, got what we programmed. nel_01 0.85-1.95 e20 m-2. 3 H-modes, some RF trips. Density rises are slower, radiation still rising. PCI sees weak QC modes, looks like we are borderline EDA. Next shot, raise target density to 1.0e20. ----------------------------------------------------------------------------- 1010726006 hubbard SESSION_LEADER Jul 26 2001 12:47:49:786PM . . . . . . . . . . . . . . . . . . . . Target density nel_01 0.95e20 m-2. (Plus a programmed 'puff' at 0.7 secs, which we will remove for the next shot.) Only got ~600 kW RF, so stayed in L-mode. Try this one again. H/D stayed ~6%. ----------------------------------------------------------------------------- 1010726007 hubbard SESSION_LEADER Jul 26 2001 1:36:08:830PM . . . . . . . . . . . . . . . . . . . . Target density nel_01 0.95e20 m-2. Only got ~750 kW RF, so stayed in L-mode. ----------------------------------------------------------------------------- 1010726008 hubbard SESSION_LEADER Jul 26 2001 1:41:34:296PM . . . . . . . . . . . . . . . . . . . . Got a short H-mode rather late, 0.8-0.91 secs. Upon checking the gas and neutral traces, found that the small change in density demand after shot 5 has resulted in ~5X more gas. This may well account for the higher H-mode power threshold. The H-mode looked rather ELM-free, despite more gas. A big injection (from where?) apparently ended the H-mode. ALso, D-port RF had a fault indication which required power room work to check out before proceeding. Luckily, it turned out not to be serious. ----------------------------------------------------------------------------- 1010726010 hubbard SESSION_LEADER Jul 26 2001 2:30:57:250PM . . . . . . . . . . . . . . . . . . . . Longer, high density H-mode, with fairly steady 1.8 MW RF. Plasma cools a lot throughout (core and edge; has the character of a Type III ELMy discharge, though so obvious ELMs are seen. nel 1.03-2.3e20; ECE cutoff. Next shot, reduce target density to 9e19m-2, as on shot 5 (a better EDA). ----------------------------------------------------------------------------- 1010726011 hubbard SESSION_LEADER Jul 26 2001 2:50:17:130PM . . . . . . . . . . . . . . . . . . . . Several pretty ELM-free H-modes. This condition proves very difficult for RF to couple to; many phase balance faults; 1.8 MW D+E. Next shot, try adding J-port at beginning too. ----------------------------------------------------------------------------- 1010726012 hubbard SESSION_LEADER Jul 26 2001 3:18:28:136PM . . . . . . . . . . . . . . . . . . . . Got 2.3 MW D and E, no J. Fewer trips; some caused by injections from upper vessel. Series of H-modes, weak QC mode but density, Prad ramping up. Next shot: nel_target 0.95 e20 m-2, try again for J-port. ---------------------------------------------------------------------------- 1010726013 hubbard SESSION_LEADER Jul 27 2001 11:16:04:133AM . . . . . . . . . . . . . . . . . . . . Got 3.3 MW briefly, including J-port. 1 H-mode, steadier density, very hot initially (Te8 500 eV). Between shot ECDC did keep H/D lower, 6-8%. Do this from here on. Big injection and disruption 1.05 secs. ----------------------------------------------------------------------------- 1010726014 hubbard SESSION_LEADER Jul 26 2001 3:56:44:993PM . . . . . . . . . . . . . . . . . . . . Got 3.8 MW RF, decent H-mode. Moderate density rise ~0.7-0.8 secs. This will probably be the best comparison point for pedestals; Jerry got good profiles. Prad is unfortunately rising, and Tedge eroding; hints of ECE cutoff late. Unfortunately, the high power leads to a disruption at ~0.85 secs. For next shot, keep target same and do a slow power ramp, to get threshold conditions. ---------------------------------------------------------------------------- 1010726015 hubbard SESSION_LEADER Jul 26 2001 4:28:22:756PM . . . . . . . . . . . . . . . . . . . . Nice ramp up to 2 MW, as requested. Got L-H threshold at 1.134 s, 1.8 MW. This shot should be good for threshold parameter comparisons. The H-mode part, though short, had fairly steady density (ELMy periods, perhaps?) and could be used for a lower power comparison point. For now, declare victory on ASDEX-Upgrade part of the run, and move to part B, L-H-L hysteresis at normal shape, 800 kA. Start with a rampup waveform as on this shot, to get tunes. ----------------------------------------------------------------------------- 1010726016 hubbard SESSION_LEADER Jul 26 2001 4:54:59:276PM . . . . . . . . . . . . . . . . . . . . Good shot, very steady EDA. RF ramped 0.9-2 MW (I should have started it lower). L-H at 0.65 s, 1.0 MW (pretty standard for these conditions) Next shot, tune RF for this target, and ramp power up and back down. ----------------------------------------------------------------------------- 1010726017 hubbard SESSION_LEADER Jul 26 2001 5:15:47:816PM . . . . . . . . . . . . . . . . . . . . Good shot, PRF 0.6-1.9-0 MW. Trips briefly at H-L transition. The Te increase is not large, and there were a few impurity injections. Try increasing the max power, improving the tune. ----------------------------------------------------------------------------- 1010726018 hubbard SESSION_LEADER Jul 26 2001 6:21:46:536PM . . . . . . . . . . . . . . . . . . . . Good ramp, up to 2.3 MW. Prad is also ramping up, so may not be at very high net power. ----------------------------------------------------------------------------- 1010726019 hubbard SESSION_LEADER Jul 26 2001 6:06:06:036PM . . . . . . . . . . . . . . . . . . . . Good ramp. but some kind of injection ~0.92 secs. RF trips before H-L again. TF is now 5.41 T, Ch 8 has a more obvious transient. Next shot: raise the density ----------------------------------------------------------------------------- 1010726021 hubbard SESSION_LEADER Jul 26 2001 6:51:08:640PM . . . . . . . . . . . . . . . . . . . . Requested nel_target higher, 1.2e20m-3. This resulted in very high gas puff. RF got 1.2 MW, and plasma not surprisingly remained L-mode. SInce this would probably take a few shots to tune up, we will instead try for a LOWER density, nel=7e19 m-2. ----------------------------------------------------------------------------- 1010726022 hubbard SESSION_LEADER Jul 26 2001 6:59:11:203PM . . . . . . . . . . . . . . . . . . . . Requested nel_target lower, 0.7e20m-3. Got a good EDA. Few E-port trips, but good ramps overall up and down. 0.8-1.5 x10-20 m-3 actual nel. Should be a good hysteresis shot. That's all folks! |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:37:14:160PM |
| Author: To Be Determined |
| Physop summary for 1010726: 1. Setup and run plan: Engineering setup for run 1010726: ________________________________ Overnight ECDC in deuterium. Stop at 8am. Run begins at 09:00 and ends at 19:00 Power systems the same as for shot 1010719017. 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) fill J-Bottom with 30 psi He Hybrid DISABLED(PG5) Enable the following gate valves, assuming no vacuum problems: ECE, DNB, VUV Run plan: Obtain EDA H mode in ASDEX shape for dimensionless comparison AND study L-H-L threshold (in C-Mod shape) - see run_summary_1010726 2. Run summary: The start of the run was delayed by ~ 3 hours by a host of simultaneous problems with Alternator (bearings vibrations), CAMAC and Hybrid computer. But due to self-sacrificing effort of C-Mod scientists, engineers and technicians unselfishly loyal to the cause of tokamak research, all the problems were overcome by ~ 11:30 AM. The rest of the run was quite successful from the PO point of view. We had total of 22 shots, 1 failure due to Alternator and CAMAC problems, 3 fizzles and 17 plasmas. Running ASDEX shape did not present any problem from the point of view of plasma control, however it does seem to prevent EDA H modes. On shot 15 we switched to the second half of the run plan and loaded segment 2 from a C-Mod shaped shot (see details below). The shape was then changed slightly by pulling upper x-point up and inward to move farther away from double x-point shape. Prepuff length was tweaked several times to adjust the startup. Details: 1010726001 Plasma attempt. Unsuccessful. Alternator vibration, Hybrid does not produce outputs, multiple CAMAC problems. 1010726002 Test. Hybrid fixed. CAMAC fixed. 1010726003 Plasma attempt. Increased gas prepuff to 22 msec from 18 on previous shot. Fizzle. Prepuff seems a little low (0.05 mTorr measured). For next shot: pulse_gas4 22 msec -> 25 msec. 1010726004 Plasma. Little hesitation at .015 sec. Bz is a little too high. Next shot: no PCS changes 1010726005 Plasma. Hesitation is a little worse at .015 sec. Next shot: target density up to 1e20 1010726006 Plasma. Same startup as before Next shot: get rid of gas puff at .7 sec 1010726008 Plasma. Same startup. H mode threshold is high, probably because of high midplane pressure (~1.5 mTorr). RF problems - ark in the tube. For next shot: try to lower the gas puff later in the discharge by asking for faster density ramp up before 0.3 sec 1010726009 Fizzle. Lower prepuff pressure ? For next shot: gas_pulse4 25 -> 28 msec 1010726010 Plasma. For next shot: Target density 1e20 -> 9e19 to decrease gas puff and lower H mode threshold 1010726011 Plasma. Multiple ELM-free H modes For next shot: no PCS change 1010726012 Plasma. Multiple ELM-free H modes For next shot: target .9e20 -> .95e20 1010726013 Plasma. ELM-free H mode. Disrupted at 1 sec, probably RF induced injection For next shot: no PCS change 1010726014 Plasma. ELM-free H mode, 3.8 MW RF. Disrupted at .8 sec. For next shot: no PCS change 1010726015 Plasma. H mode. For next shot: Load segment 2 from shot 1010719022. Set target to 9e19. 1010726017 Plasma. EDA H mode. For next shot: pull upper X-point up 2 cm and in 2 cm 1010726018 Plasma. EDA H mode. For next shot: increase Bt 1%: TF_current -150000 -> -151500 1010726019 Plasma. EDA H mode. For next shot: target .9e20 -> 1.2e20 1010726020 Fizzle. Too much gas ? For next shot: Lower prepuff to 28 -> 27 msec 1010726021 Plasma. No H mode. While trying to get to 1.2e20 target density, plasma was suffocated by excessive amount of gas out of pulse_gas3 For next shot: target to 7e19 1010726022 Plasma. EDA H mode. |
| Session Leader Comments | |||
| Jul 26 2001 09:45:11:937AM | Amanda Hubbard | Physics Run plan for 1010726, MP 287 Asdex H-mode similarity experiment Goal: To make high density, high power EDA H-modes in a shape identical to that in ASDEX-Upgrade 'Type II ELM' discharges. This regime, which was only recently obtained on AUG, appears rather similar to that obtained on C-Mod when power is increased into EDA H-modes. At reduced powers, AUG sometimes sees a 'quasi-coherent' mode. We would like to see if the same behaviour is observed on the two machines with the same dimensionless parameters. We will obtain edge profiles both at threshold and in the steady H-mode period. AUG will then try to match the dimensionless parameters (nu*,beta, rho*) of these discharges. Plan: 1)We will continue the plan starting from the shape and parameter development from 1010719 (see run summaries). Start from 1010719017, 5.3 T, 900 kA. Should do whatever ECDC minimizes the H/D ratio, which I presume means overnight in Deuterium. RF should use flat waveform, about 2.2 MW from D and E only. It is hoped that with lower H/D this shot will become more like EDA, rather than Type III ELMy. If conditions are moderately steady, measure pedestals, and fluctuations. Can also tune J-port at low power on these. If H-mode remains very ELM-free and transient, skip straight to 3) and 4). 2) Add power from J-port (70 MHz), at maximum available power. This will be off-axis, which is non-optimal, but should help to raise pedestal temperature. 3) 1-2 shots with ramped power, to get good data at LH threshold (D and E only) 4) Increase density, which hopefully will also improve access to EDA. A dimensionless match to the best AUG 'grassy ELM' shots would correspond to a line integrated density of 4.7e20, higher than our usual range. Increase starting density, and probably puff gas into EDA, to see how high we can get and still maintain a decent, steady H-mode (and couple enough power). ECE will probably be cut off, so good ETS data are essential. Again, use max available power without and with J-port. 5) Once the 'high density' H-mode has been characterized, use a slow power ramp to determine the corresponding threshold power and edge parameters. If we complete the experimental plan, or determine we are not likely to do so, go to **************************************************************************** Part B) L-H-L threshold experiment (which requires only 2 MW, D+E): Goal: Obtain full pedestal and power flux information during L-H-L hysteresis cycle, using RF power ramps. This will allow tests of possible functions of gradients as a function of input flux. Approach will be similar to 990915 (when we didn't have edge TS working fully). Plan: Start with 5.4 T, 800 kA plasma, shape and engineering as on 1010717, but constant Bt. Nel_04=1.0e20 m-2. Should have steady Ip flat-top by 0.4 secs or earlier, extending to 1.5 secs. RF power at 80 MHz (D + E). Ramp linearly UP, from 0-2.0 MW, 0.4-0.9 secs, FLAT 0.9-1.0 secs, and back DOWN 1.0-1.5 secs. This should get us comfortably into and out of a steady EDA H-mode. Once required data is achieved, raise density to 1.5e20m-2. Repeat with similar waveforms. If we don't get much above the L-H threshold, may want to increase max RF power slightly if possible. Reduce nel_04 to 0.7e20 m-2. Repeat RF ramps again. If time, extend density range still further. However, if we go much lower will probably run into ELM-free, non-steady H-modes with spontaneous transitions, while higher may require too much RF. | |
| Jul 26 2001 12:15:36:617PM | 1010726004 | Amanda Hubbard | Plasma. Due to lack of TCI feedback, we had VERY low density and neutral pressure. Not surprisingly, the H-Modes were ELM-free and had high pedestal temps, low ne. May be an interesting shot for low collisionality studies! |
| Jul 26 2001 12:25:10:820PM | 1010726005 | Amanda Hubbard | This time, got what we programmed. nel_01 0.85-1.95 e20 m-2. 3 H-modes, some RF trips. Density rises are slower, radiation still rising. PCI sees weak QC modes, looks like we are borderline EDA. Next shot, raise target density to 1.0e20. |
| Jul 26 2001 12:47:49:787PM | 1010726006 | Amanda Hubbard | Target density nel_01 0.95e20 m-2. (Plus a programmed 'puff' at 0.7 secs, which we will remove for the next shot.) Only got ~600 kW RF, so stayed in L-mode. Try this one again. H/D stayed ~6%. |
| Jul 26 2001 01:36:08:830PM | 1010726007 | Amanda Hubbard | Target density nel_01 0.95e20 m-2. Only got ~750 kW RF, so stayed in L-mode. |
| Jul 26 2001 01:41:34:297PM | 1010726008 | Amanda Hubbard | Got a short H-mode rather late, 0.8-0.91 secs. Upon checking the gas and neutral traces, found that the small change in density demand after shot 5 has resulted in ~5X more gas. This may well account for the higher H-mode power threshold. The H-mode looked rather ELM-free, despite more gas. A big injection (from where?) apparently ended the H-mode. ALso, D-port RF had a fault indication which required power room work to check out before proceeding. Luckily, it turned out not to be serious. |
| Jul 26 2001 02:30:57:250PM | 1010726010 | Amanda Hubbard | Longer, high density H-mode, with fairly steady 1.8 MW RF. Plasma cools a lot throughout (core and edge; has the character of a Type III ELMy discharge, though so obvious ELMs are seen. nel 1.03-2.3e20; ECE cutoff. Next shot, reduce target density to 9e19m-2, as on shot 5 (a better EDA). |
| Jul 26 2001 02:50:17:130PM | 1010726011 | Amanda Hubbard | Several pretty ELM-free H-modes. This condition proves very difficult for RF to couple to; many phase balance faults; 1.8 MW D+E. Next shot, try adding J-port at beginning too. |
| Jul 26 2001 03:18:28:137PM | 1010726012 | Amanda Hubbard | Got 2.3 MW D and E, no J. Fewer trips; some caused by injections from upper vessel. Series of H-modes, weak QC mode but density, Prad ramping up. Next shot: nel_target 0.95 e20 m-2, try again for J-port. |
| Jul 27 2001 11:16:04:133AM | 1010726013 | Amanda Hubbard | Got 3.3 MW briefly, including J-port. 1 H-mode, steadier density, very hot initially (Te8 500 eV). Between shot ECDC did keep H/D lower, 6-8%. Do this from here on. Big injection and disruption 1.05 secs. |
| Jul 26 2001 03:56:44:993PM | 1010726014 | Amanda Hubbard | Got 3.8 MW RF, decent H-mode. Moderate density rise ~0.7-0.8 secs. This will probably be the best comparison point for pedestals; Jerry got good profiles. Prad is unfortunately rising, and Tedge eroding; hints of ECE cutoff late. Unfortunately, the high power leads to a disruption at ~0.85 secs. For next shot, keep target same and do a slow power ramp, to get threshold conditions. |
| Jul 26 2001 04:28:22:757PM | 1010726015 | Amanda Hubbard | Nice ramp up to 2 MW, as requested. Got L-H threshold at 1.134 s, 1.8 MW. This shot should be good for threshold parameter comparisons. The H-mode part, though short, had fairly steady density (ELMy periods, perhaps?) and could be used for a lower power comparison point. For now, declare victory on ASDEX-Upgrade part of the run, and move to part B, L-H-L hysteresis at normal shape, 800 kA. Start with a rampup waveform as on this shot, to get tunes. |
| Jul 26 2001 04:54:59:277PM | 1010726016 | Amanda Hubbard | Good shot, very steady EDA. RF ramped 0.9-2 MW (I should have started it lower). L-H at 0.65 s, 1.0 MW (pretty standard for these conditions) Next shot, tune RF for this target, and ramp power up and back down. |
| Jul 26 2001 05:15:47:817PM | 1010726017 | Amanda Hubbard | Good shot, PRF 0.6-1.9-0 MW. Trips briefly at H-L transition. The Te increase is not large, and there were a few impurity injections. Try increasing the max power, improving the tune. |
| Jul 26 2001 06:21:46:537PM | 1010726018 | Amanda Hubbard | Good ramp, up to 2.3 MW. Prad is also ramping up, so may not be at very high net power. |
| Jul 26 2001 06:06:06:037PM | 1010726019 | Amanda Hubbard | Good ramp. but some kind of injection ~0.92 secs. RF trips before H-L again. TF is now 5.41 T, Ch 8 has a more obvious transient. Next shot: raise the density |
| Jul 26 2001 06:51:08:640PM | 1010726021 | Amanda Hubbard | Requested nel_target higher, 1.2e20m-3. This resulted in very high gas puff. RF got 1.2 MW, and plasma not surprisingly remained L-mode. SInce this would probably take a few shots to tune up, we will instead try for a LOWER density, nel=7e19 m-2. |
| Jul 26 2001 06:59:11:203PM | 1010726022 | Amanda Hubbard | Requested nel_target lower, 0.7e20m-3. Got a good EDA. Few E-port trips, but good ramps overall up and down. 0.8-1.5 x10-20 m-3 actual nel. Should be a good hysteresis shot. That's all folks! |
| Physics Operator Comments | |||
| Jul 26 2001 09:01:08:913AM | Dmitri Mossessian | Engineering setup for run 1010726: ________________________________ Overnight ECDC in deuterium. Stop at 8am. Run begins at 09:00 and ends at 19:00 Power systems the same as for shot 1010719017. 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) fill J-Bottom with 30 psi He Hybrid DISABLED(PG5) Enable the following gate valves, assuming no vacuum problems: ECE, DNB, VUV Run plan - see Amanda's bulletin. _______________________________________________ Loaded from 1010719017. Coldstart OK. | |
| Jul 26 2001 10:01:39:577AM | 1010726001 | Dmitri Mossessian | Plasma attempt. Unsuccessful. Alternator vibration, Hybrid does not produce outputs, multyple CAMAC problems. |
| Jul 26 2001 11:27:29:787AM | 1010726002 | Dmitri Mossessian | Test. Hybrid fixed. CAMAC fixed. |
| Jul 26 2001 11:40:42:737AM | 1010726003 | Dmitri Mossessian | Plasma attempt. Increased gas prepuff to 22 msec from 18 on previous shot. Fizzle. Prepuff seems a little low (0.05 mTorr measured). For next shot: pulse_gas4 22 msec -> 25 msec. |
| Jul 26 2001 12:07:54:070PM | 1010726004 | Dmitri Mossessian | Plasma. Little hesitation at .015 sec. Bz is a little too high. Next shot: no PCS changes |
| Jul 26 2001 12:20:42:093PM | 1010726005 | Dmitri Mossessian | Plasma. Hesitation is a little worseat .015 sec. Next shot: target density up to 1e20 |
| Jul 26 2001 12:38:04:220PM | 1010726006 | Dmitri Mossessian | Plasma. Same startup as before Next shot: get rid of gas puff at .7 sec |
| Jul 26 2001 01:34:02:530PM | 1010726008 | Dmitri Mossessian | Plasma. Same startup. H mode threshold is high, probably because of high midplane pressure (~1.5 mTorr). RF problems - ark in the tube. For next shot: try to lower the gas puff later in the discharge by asking for faster density ramp up before 0.3 sec |
| Jul 26 2001 02:03:24:163PM | 1010726009 | Dmitri Mossessian | Fizzle. Lower prepuff pressure ? For next shot: gas_pulse4 25 -> 28 msec |
| Jul 26 2001 02:23:57:830PM | 1010726010 | Dmitri Mossessian | Plasma. For next shot: Target density 1e20 -> 9e19 to decrease gas puff and lower H mode threshold |
| Jul 26 2001 03:07:38:740PM | 1010726011 | Dmitri Mossessian | Plasma. Multiple ELM-free H modes For next shot: no PCS change |
| Jul 26 2001 03:08:14:960PM | 1010726012 | Dmitri Mossessian | Plasma. Multiple ELM-free H modes For next shot: target .9e20 -> .95e20 |
| Jul 26 2001 04:13:57:713PM | 1010726013 | Dmitri Mossessian | Plasma. ELM-free H mode. Disrupted at 1 sec, probably RF induced injection For next shot: no PCS change |
| Jul 26 2001 04:14:41:903PM | 1010726014 | Dmitri Mossessian | Plasma. ELM-free H mode, 3.8 MW RF. Disrupted at .8 sec. For next shot: no PCS change |
| Jul 26 2001 04:20:33:977PM | 1010726015 | Dmitri Mossessian | Plasma. H mode. For next shot: Load segment 2 from shot 1010719022. SEt target to 9e19. |
| Jul 26 2001 04:40:36:090PM | 1010726015 | Dmitri Mossessian | Plasma. EDA H mode. For next shot: Increased prportional gain on ip between .3 and .6 sec |
| Jul 26 2001 05:21:33:000PM | 1010726016 | Dmitri Mossessian | Plasma. EDA H mode. For next shot: no PCS change |
| Jul 26 2001 05:22:16:987PM | 1010726017 | Dmitri Mossessian | Plasma. EDA H mode. For next shot: pull upper X-point up 2 cm and in 2 cm |
| Jul 26 2001 05:44:18:387PM | 1010726018 | Dmitri Mossessian | Plasma. EDA H mode. For next shot: increase Bt 1%: TF_current -150000 -> -151500 |
| Jul 26 2001 06:02:41:140PM | 1010726019 | Dmitri Mossessian | Plasma. EDA H mode. For next shot: target .9e20 -> 1.2e20 |
| Jul 26 2001 06:21:24:850PM | 1010726020 | Dmitri Mossessian | Fizzle. Too much gas ? For next shot: Lower prepuff to 28 -> 27 msec |
| Jul 26 2001 06:45:35:753PM | 1010726021 | Dmitri Mossessian | Plasma. No H mode. While trying to get to 1.2e20 target density, plasma was suffocated by excessive amount of gas out of pulse_gas3 For next shot: target to 7e19 |
| Jul 26 2001 06:57:07:700PM | 1010726022 | Dmitri Mossessian | Plasma. EDA H mode. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:34:14:040AM | Plasma | Bad | Alternator Vibration on Bearing 2 of Fly wheel |
| 2 | 11:11:49:257AM | Test | Ok | |
| 3 | 11:30:15:467AM | Plasma | Ok | |
| 4 | 11:49:05:233AM | Plasma | Ok | |
| 5 | 12:10:25:183PM | Plasma | Ok | |
| 6 | 12:31:55:363PM | Plasma | Ok | |
| 7 | 12:48:37:083PM | Plasma | Ok | |
| 8 | 01:09:54:173PM | Plasma | Ok | |
| 9 | 01:53:27:223PM | Plasma | Ok | |
| 10 | 02:08:43:377PM | Plasma | Ok | |
| 11 | 02:29:03:247PM | Plasma | Ok | |
| 12 | 02:50:53:960PM | Plasma | Ok | |
| 13 | 03:16:06:540PM | Plasma | Ok | |
| 14 | 03:41:09:383PM | Plasma | Ok | |
| 15 | 04:05:46:917PM | Plasma | Ok | |
| 16 | 04:30:56:793PM | Plasma | Ok | |
| 17 | 04:56:47:653PM | Plasma | Ok | |
| 18 | 05:21:19:123PM | Plasma | Ok | |
| 19 | 05:49:12:473PM | Plasma | Ok | |
| 20 | 06:12:29:770PM | Plasma | Ok | |
| 21 | 06:37:28:473PM | Plasma | Ok | |
| 22 | 06:50:04:967PM | Plasma | Ok | |