| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Miklos Porkolab,Martin Greenwald |
| Physics operator(s): | Dmitri Mossessian |
| Engineering operator(s): | Ed Fitzgerald,Bill Parkin,Gary Dekow |
| Engineering Operator Run Comment |
| MP#324A ITB Formation SL:Porkolab; PO:Mossessian; EO:Dekow/Fitz/Parkin |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:03:540PM |
| Author: Miklos Porkolab |
| MP#324A ITB Formation with Two-Frequency ICRF in Optimized Shear Plasmas with Ip Ramp Session leader: M. Porkolab Physics operator: D. Mossessian ECDC overnight in D2 at 2e-4 Torr, stopping by 07:00. Bake at 60 C overnight as well. Run begins at 09:00 and ends at 17:00. Power Supplies as on 1040309029 A-coils 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) leave B-side upper as is Hybrid DISABLED (PG2) fill C-side with 30 psi D2 Hybrid enabled (PG3) Enable the following gate valves, assuming no vacuum problems: ECE, VUV, DNB Run plan: Post boronization recovery + MP324A. Load 1021025005. The shot is limited on the inner nose at around 0.2 - 0.24 sec. If this is not desirable, the necessary changes in configuration can be made during boronization recovery phase. A. 8 shots at 5.4 Tesla Ramp current and divert discharge as reference discharge. Apply 70 MHz power up to 1.0 MW at 0.100 sec, apply 80 MHz Power at 0.080 sec into discharge, up to 2 MW. After 4 shots, with at least 1 MW at each frequency, start to divert the discharge earlier than the nominal 0.22 -0.24 sec, while maintaining power; the goal is to delay sawteeth as much as possible, and maximize stored energy, or ITB, as well as the edge pedestal temperature; monitor ELMs and Alfven wave cascade; try to obtain Grand Alfven wave cascade; monitor with PCI as well as several magnetic loops to measure the n number of the cascade modes; B. 5 shots If obtain good target shot, with lots of cascades, increase power further at either or both frequencies and optimize shots for cascades and/or ELMs and /or stored energy or neutrons or ITB Also, move RF powers earlier to see if could delay sawteeth further; Move relative timing of RF powers (frequencies) also to achieve goal . C.. 5 Shots. Repeat at 5.7 T D. 5 Shots Repeat at 5.0 T E. 5 Shots Repeat at 4.6 T. ------------------------------------------------------------------------------- 001-004 cycle tests 005 No plasma; computer problems 006 5.4 T. Good shot; Had about 1 MW power (still not well tuned); Got ELM free H mode at 0.24 sec, just like in the last campaign; Start increasing RF power, also, attempt to divert earlier on the following shots. 007 5.4 T. Good shot; Had about 1 MW power and after 0.22 sec, had 2 MW Got ELM free H mode at 0.24 sec, just like in the last campaign; Attempt to divert plasma earlier on the following shots. 008 5.4 T. Good shot; Had about 1 MW power and after 0.19 sec, had 2 MW. Got ELM free H mode at 0.26 sec, but current rise is already finished. Attempted to divert plasma earlier, but only marginally successfull. 009 5.4 T. Good shot; Had about 1 MW power and after 0.19 sec, had 2 MW. Got ELM free H mode at 0.20 sec at 2.0 MW, then power dropped back to 1.5 MW, then recovered to 2.6 MW by 0.26 sec. ELM free H mode remained good, although H factor is only about 1 (namely L mode). Attempted to divert plasma earlier, but only marginally successful. Will try again on next shot. 010 5.4 T. Good shot; Had about 2.5 MW power early (0.05 sec) then power dropped back to 1.5 MW, then back to 2.5 MW and back to 2.0, then back up to 2.5 MW. Neutron rate increased to 8x10e(12). Got ELM free H mode after 0.20 sec at 2.5 MW, H factor is only about 1 (namely L mode). Attempted to divert plasma earlier, but only marginally successful. Will try again on next shot. 011 5.4 T. Had injection at 0.2 sec, disruption. Lost 70 MHz driver tube after shot 10, before shot 11. No J port power. 012 5.4 T. Running without 70 MHz. Getting injections. There is no evidence of cascades. Keep pre-gaspuff down, so operate at lower densities. 013 5.4 T. Running without 70 MHz. still getting injections. There is no evidence of cascades. Keep pre-gaspuff down, so operate at lower densities. Second injection at 0.22 sec. RF very irregular. 014 Still having problems with the early control system at 0.1 sec; will try to correct it since that would be the time for Alfven cascades (which we do not see on either PCI or MHD loops) 015 Improved control system, still a small "glitch" at 0.1 sec, but much better than before. Power is smooth at 1.5 MW. Getting ELM free H mode out to 0.45 sec. Current ramps to 0.35 sec. Will try to go to 2.0 MW next shot. 016 Improved control system, got a large glitch, RF drops out at 0.1 sec. Another RF dropout at 0.24 sec. No Alfven wave cascade. Will raise the pre-puff density upward to see if the glitch goes away. 017 Increased pre-puff to 3/4 way where we were this morning, to see if glitch goes away at higher density. Unfortunately did not get rid off it. No Cascade, RF power also trips at 0.1 sec. Will go back to full pre-puff on next shot. 018 Increased pre-puff all the way to where we were this morning. Shot was aborted. 019 Increased pre-puff all the way to where we were this morning. Repeat shot 018. Glitch at 0.1 sec disappeared ! Shot ran until 0.35 sec, then disrupted. However, up to this time the RF ran at 2.0 MW, and see top of Alfven wave "cascades"(?) between 0.12-0.18 sec. See it on both PCI and magnetic loops. Repeat shot at higher power, perhaps can get another 0.3 MW out of the E tube. 020 Increased pre-puff all the way to where we were this morning. Repeat shot at higher power, perhaps can get another 0.3 MW out of the E tube. Fizzle. Repeat again. 021 Increased pre-puff all the way to where we were this morning. Repeat shot at higher power, perhaps can get another 0.3 MW out of the E tube. Good shot, power up to 2.3 MW, steady from 0.08 sec to 0.15 sec, then drops out by 0.22 sec. See Alfven wave cascades from 0.12 to 0.15 sec. Also get ELMS(!) from 0.17 to 0.22 sec. Current ramp seems to be faster, up to 0.9 MA in 200 msec. 022 Increased pre-puff all the way to where we were this morning. Repeat shot at higher power, perhaps can get another 0.3 MW out of the E tube. Good shot, power up to 2.5 MW, steady from 0.08 sec to 0.13 sec, then drops out by 0.13, recovers at 0.18 sec. See Alfven wave cascades from 0.12 to 0.15 sec, but spectrum is weak, need more power, but cannot get it.. Current ramp seems to be faster, up to 0.9 MA in 200 msec. ----------------------------------------------------------- The run is transferred over to mini- proposal 300, running at 4.5Tesla, with off-axis RF on. martin Greenwald becomes Session Leader. run summary: The run went well in the initial phase, namely the antennas conditioned up well and the shots very very similar to last year's campaign: The inner nose limited plasma was diverted by 0.24 sec, while the current was still ramping toward 0.9 MA. We got ELM free H modes early on, without significant impurity injection. Stored energies were typically 100KJ with about 2 MW of injected power, split between the two frequencies. This corresponds to ITER 89L mode scaling, however. Attempts at diverting earlier than 0.24 second failed, however. We slowed down the current ramp so it lasted until 0.35 sec, but it did not substantially change things. Since the densities were relatively high even during ramp, there was little evidence of Alfven wave cascades. Unfortunately, the driver tube for the J-port antenna (70 MHz) failed after shot 10, and we were forced to operate at 80 MHz only, with power limited to a few MWs. We have therefore turned our attention to look for Alfven Wave Cascades, which required a lowering of the density during rampup. We did this by cutting back into half the initial gas puff. Unfortunately an undesirable glitch developed with a resulting spike in several signals and a drop-out of the RF systems just when the cascades would develop (0.11-0.16 sec, typically). We spent a number of shots to eliminate this problem with no success. Therefore, we increased the gas pre-puff in 25 % increments back to where we started in the morning, and on shot 19 the glitch disappeared as we got back to the original value. On the next 3 shots we raised the power to a maximum of 2.5 MW (shot 22) and weak Alfven wave cascade spectrum showed up on both the PCI and the magnetic loops, especially on shot19, 21, 22. By the way, we also got nice ELMS on shot 21 as the current ramp rate increased to 900kA in 0.2 sec. Since the maximum power could not be raised beyond 2.5 MW between E and D ports we have abandoned the campaign and gave it over to Martin Greenwald to pursue MP 300 at 4.5 T. It is clear that in addition to continue with the two frequency ramping experiment, we whould pursue another day of current ramp at full power at 80 MHz to study Alfven wave cascades at maximum power, for example at 4.0 MW. This should allow us to obtain a rich spectrum af cascades for analysis. |
| Entered: Jul 7 2004 03:49:03:553PM |
| Author: Martin Greenwald |
| Run Summary for 1040318 Continuation of MP 300 - BT scans and ITB hysteresis Session Leader - Greenwald Phys Op - Mossessian Background and approach: We've observed a sharp threshold in BT for formation of ITBs produced by off-axis RF heating. The threshold is interpreted as an effect of deposition radius, with barriers formed when the ICRF resonance location is greater than about |r/a| = 0.45. The threshold is seen for deposition on both the low and high field side and is quite sharp - amounting to about 0.1 T or less than 5-10% in r/a. The point of today's experiment is to probe this threshold boundary dynamically to look for hysteresis which could help categorize the transition and shed light on the underlying physics. Plan: 1. Start at with a shot like 1040311012 - a Bt ramp - upward starting somewhat after the ITB transition and ramping at a rate that would got us to about 5 T before the end of flat-top 2. Modify the ramp to find the point where the ITB is lost 3. Repeat with ramp in opposite direction Results: Pretty good results in just two hours (followed Ip ramp experiments) ITBs were produced routinely, radiation seemed low and ITBs and H-modes were not plagued with back transitions. The RF ran well and coupled well. Ramping Bt did not extend range of ITBs to any significant extent. Clearest comparison is 027, 028 compared to 030 and 031. Even with finite ramp rate - which tends to blur transition point, variation in Bt is 4.75 +/- 0.1 (2% !!). It is possible that with slower ramps, the transition field would be identical. Shot Bt ramp result 24 4.6 - 5.0 v. weak itb which is lost after 1.0 second, Bt ~ 4.7 25 4.6 - 4.8 v. weak or not itb 26 4.4 - 4.8 weak itb - unclear if it is lost even at 4.8 27 4.4 - 5.2 weak itb - lost about 1.1 sec, Bt ~ 4.8 29 4.4 - 5.0 weak itb - lost about 1.3 sec Bt ~ 4.85 30 5.0 - 4.4 weak itb - begins at 1.15 sec, Bt ~ 4.65 31 5.0 - 4.4 weak itb - begins at 1.15 sec Bt ~ 4.65 |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:36:49:537PM |
| Author: Dmitri Mossessian |
| Physop summary for 1040318. Session leader: M. Porkolab MP324A, M. Greenwald MP300 Physics operator: D. Mossessian ____________________________________ Engineering setup: ECDC overnight in D2 at 2e-4 Torr, stopping by 07:00. Bake at 60 C overnight as well. Run begins at 09:00 and ends at 17:00. Power Supplies as on 1040309029 A-coils 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) leave B-side upper as is Hybrid DISABLED (PG2) fill C-side with 30 psi D2 Hybrid enabled (PG3) Enable the following gate valves, assuming no vacuum problems: ECE, VUV, DNB Run plan: Post boronization recovery + MP324A. MP#324A ITB Formation with Two-Frequency ICRF in Optimized Shear Plasmas with Ip Ramp Load 1021025005. The shot is limited on the inner nose at around 0.2 - 0.24 sec. If this is not desirable, the necessary changes in configuration can be made during boronization recovery phase. A. 8 shots at 5.4 Tesla Ramp current and divert discharge as reference discharge. Apply 70 MHz power up to 1.0 MW at 0.100 sec, apply 80 MHz Power at 0.080 sec into discharge, up to 2 MW. After 4 shots, with at least 1 MW at each frequency, start to divert the discharge earlier than the nominal 0.22 -0.24 sec, while maintaining power; the goal is to delay sawteeth as much as possible, and maximize stored energy, or ITB, as well as the edge pedestal temperature; monitor ELMs and Alfven wave cascade; try to obtain Grand Alfven wave cascade; monitor with PCI as well as several magnetic loops to measure the n number of the cascade modes; B. 5 shots If obtain good target shot, with lots of cascades, increase power further at either or both frequencies and optimize shots for cascades and/or ELMs and /or stored energy or neutrons or ITB Also, move RF powers earlier to see if could delay sawteeth further; Move relative timing of RF powers (frequencies) also to achieve goal . C.. 5 Shots. Repeat at 5.7 T D. 5 Shots Repeat at 5.0 T E. 5 Shots Repeat at 4.6 T. ___________________________________ Summary: We started with MP324A applying RF power early in current ramp up. For a while we tried to tweak CLEARIN and RXL before 0.2 sec to make plasma to divert earlier, without much success. When on shot 12 we lowered the PG3 puff in segment 1 to bring down the density during current ramp, an injection appeared at 0.1 sec (segment switch time). We tried to change various waveforms to smooth out the transition between segments, but the only way to get rid of the injection turned out to bring the puff back on. RF had problems and could not produce sufficient power to continue MP324A, so after shot 22 we switched to MP300 - ITB hysteresis. We had a few computer problems leading to missing shot cycles, and several breakers failures, reason unknown. Startup was generally very reliable, except for shot 20, which was a fizzle for no apparent reason. Total - 26 shots 1 Fizzle 1 Dud (too much prepuff on the first shot) 24 Plasmas Details: ---------------------------------------------------------------------------- 1040318005 Dud. PO fault - I forgot to load segment 1 from one of the recent shots. Seg 1 in 102... shot has 30 msec of prepuf. Next shot - load seg 1 from last shot from yesterday 1040317032. Changed PG4 to 15 msec from 17. ---------------------------------------------------------------------------- 1040318006 Plasma. Startup is good. There is a large injection at ~0.07 sec that shows up as a dip in the current rise. It may be due to some arcing in E-port which comes up at that time. Next shot - no change. ---------------------------------------------------------------------------- 1040318007 Plasma. Startup is good. Next shot - attempting to make plasma diverted earlier. Move CLEARIN and RXL rampup 0.05 sec early. CLEARIN first non-zero point 0.25 -> 0.2, RXL 0.35 -> 0.3 ---------------------------------------------------------------------------- 1040318008 Plasma. Startup is good. Diverted at about .22 Next shot - move RXL rampup earlier, starting at 0.2 sec ---------------------------------------------------------------------------- 1040318009 Plasma. Startup is good. A series of large injections starts at 0.35 and kills the H-mode. Next shot - move RXL and CLEARIN rampup even earlier. ---------------------------------------------------------------------------- 1040318010 Plasma. Startup is good. Still diverted at .22 sec. Early rampup in CLEARIN does not help it getting diverted earlier - plasma still sits on inner nose up to 0.22 s. Next shot - Move first positive CLEARIN point later to .15 s. Moving RXL startup to 0. sec. Slow down current rampup to reach 0.9 sec at 0.3 (insrtead of 0.2 sec) ---------------------------------------------------------------------------- 1040318011 Plasma. Startup is good. Still diverted at .22 sec Next - lower PG3 in segment 1 90 -> 50 V to get lower density during current ramp. ---------------------------------------------------------------------------- 1040318012 Plasma. Next shot - no change. ---------------------------------------------------------------------------- 1040318014 Plasma. Next shot - raise current at .1 sec to 65 kA to avoid discontinuity between seg 1 and 2. ---------------------------------------------------------------------------- 1040318015 Plasma. There is still an injection at 0.1 sec which may be attributed to segment switch. Next shot - move RXL rampup start after 0.1 sec ---------------------------------------------------------------------------- 1040318016 Plasma. Still bad at 0.1 sec Next shot - bring PG3 back up to 70 V in seg 1. ---------------------------------------------------------------------------- 1040318017 Plasma. Still bad at 0.1 sec Next shot - bring PG3 back up to 100 V in seg 1. ---------------------------------------------------------------------------- 1040318019 Plasma. 0.1 sec is OK. Disrupted at 0.34 during H-mode due to large injection. Next shot - no change ---------------------------------------------------------------------------- 1040318020 Fizzle. No obvious reason Next shot - no change ---------------------------------------------------------------------------- 1040318022 Plasma. Next - switch to MP300 - ITB hysteresis. Load shot 1040311012. Changed PG4 to 15 msec in seg 1. ---------------------------------------------------------------------------- 1040318024 Plasma. Next - change Bt rampup between 0.6 and 1.5 sec. ---------------------------------------------------------------------------- 1040318025 Plasma. Next - change Bt rampup between 0.6 and 1.5 sec to start from 4.5 instead of 4.6T ---------------------------------------------------------------------------- 1040318026 Plasma. Next - change Bt rampup between 0.6 and 1.5 sec to start end at 5 T instead of 4.8 T ---------------------------------------------------------------------------- 1040318029 Plasma. Next - reverse Bt ramp between 0.6 and 1.5 sec ---------------------------------------------------------------------------- 1040318030 Plasma. Next - repeat |
| Session Leader Comments | |||
| Mar 18 2004 02:15:27:900PM | Martin Greenwald | Continue MP 300 Session Leader - Greenwald Phys Op - Mossessian Background and approach: We've observed a sharp threshold in BT for formation of ITBs produced by off-axis RF heating. The threshold is interpreted as an effect of deposition radius, with barriers formed when the ICRF resonance location is greater than about |r/a| = 0.45. The threshold is seen for deposition on both the low and high field side and is quite sharp - amounting to about 0.1 T or less than 5-10% in r/a. The point of today's experiment is to probe this threshold boundary dynamically to look for hysteresis which could help categorize the transition and shed light on the underlying physics. Plan: 1. Start at with a shot like 1040311012 - 4.5 T - demonstrate ITB with Bt ramp - upward starting somewhat after the ITB transition and ramping at a rate that gets to about 4.9 T before the end of flat-top If the ITB is not lost, increase Bt ramp rate 3. Start with Bt above the threshold ~ 4.8T - demonstrate lack of ITB 4. Ramp Bt down at the rate established in 2. | |
| Mar 18 2004 09:28:59:680AM | 1040318005 | Miklos Porkolab | 005 No plasma; computer problems |
| Mar 18 2004 10:00:43:163AM | 1040318006 | Miklos Porkolab | 006 5.4 T. Good shot; Had about 1 MW power (still not well tuned); Got ELM free H mode at 0.24 sec, just like in the last campaign; Start increasing RF power, also, attempt to divert earlier on the following shots. |
| Mar 18 2004 10:18:06:510AM | 1040318007 | Miklos Porkolab | 007 5.4 T. Good shot; Had about 1 MW power and after 0.22 sec, had 2 MW Got ELM free H mode at 0.24 sec, just like in the last campaign; Attempt to divert plasma earlier on the following shots. |
| Mar 18 2004 10:38:33:520AM | 1040318008 | Miklos Porkolab | 008 5.4 T. Good shot; Had about 1 MW power and after 0.19 sec, had 2 MW. Got ELM free H mode at 0.26 sec, but current rise is already finished. Attempted to divert plasma earlier, but only marginally successfull. |
| Mar 18 2004 10:50:30:150AM | 1040318009 | Miklos Porkolab | 009 5.4 T. Good shot; Had about 1 MW power and after 0.19 sec, had 2 MW. Got ELM free H mode at 0.20 sec at 2.0 MW, then power dropped back to 1.5 MW, then recovered to 2.6 MW by 0.26 sec. ELM free H mode remained good, although H factor is only about 1 (namely L mode). Attempted to divert plasma earlier, but only marginally successful. Will try again on next shot. |
| Mar 18 2004 11:23:06:137AM | 1040318010 | Miklos Porkolab | 010 5.4 T. Good shot; Had about 2.5 MW power early (0.05 sec) then power dropped back to 1.5 MW, then back to 2.5 MW and back to 2.0, then back up to 2.5 MW. Neutron rate increased to 8x10e(12). Got ELM free H mode after 0.20 sec at 2.5 MW, H factor is only about 1 (namely L mode). Attempted to divert plasma earlier, but only marginally successful. Will try again on next shot. |
| Mar 18 2004 11:25:33:970AM | 1040318011 | Miklos Porkolab | 011 5.4 T. Had injection at 0.2 sec, disruption. Lost 70 MHz driver tube after shot 10, before shot 11. No J port power. |
| Mar 18 2004 11:53:30:620AM | 1040318012 | Miklos Porkolab | 012 5.4 T. Running without 70 MHz. Getting injections. There is no evidence of cascades. Keep pre-gaspuff down, so operate at lower densities. |
| Mar 18 2004 11:56:48:267AM | 1040318013 | Miklos Porkolab | 013 5.4 T. Running without 70 MHz. still getting injections. There is no evidence of cascades. Keep pre-gaspuff down, so operate at lower densities. Second injection at 0.22 sec. RF very irregular. |
| Mar 18 2004 12:19:40:660PM | 1040318014 | Miklos Porkolab | 014 Still having problems with the early control system at 0.1 sec; will try to correct it since that would be the time for Alfven cascades (which we do not see on either PCI or MHD loops) |
| Mar 18 2004 12:27:04:080PM | 1040318015 | Miklos Porkolab | 015 Improved control system, still a small "glitch" at 0.1 sec, but much better than before. Power is smooth at 1.5 MW. Getting ELM free H mode out to 0.45 sec. Current ramps to 0.35 sec. Will try to go to 2.0 MW next shot. |
| Mar 18 2004 12:36:36:687PM | 1040318016 | Miklos Porkolab | 016 Improved control system, got a large glitch, RF drops out at 0.1 sec. Another RF dropout at 0.24 sec. No Alfven wave cascade. Will raise the pre-puff density upward to see if the glitch goes away. |
| Mar 18 2004 12:51:15:913PM | 1040318017 | Miklos Porkolab | 017 Increased pre-puff to 3/4 way where we were this morning, to see if glitch goes away at higher density. Unfortunately did not get rid off it. No Cascade, RF power also trips aaaat 0.1 sec. Will go back to full pre-puff on next shot. |
| Mar 18 2004 01:11:30:943PM | 1040318018 | Miklos Porkolab | Increased pre-puff all the way to where we were this morning. Shot was aborted. |
| Mar 18 2004 01:24:13:993PM | 1040318019 | Miklos Porkolab | Increased pre-puff all the way to where we were this morning. Repeat shot 018. Glitch at 0.1 sec disappeared ! Shot ran until 0.35 sec, then disrupted. However, up to this time the RF ran at 2.0 MW, and see top of Alfven wave "cascades"(?) between 0.12-0.18 sec. See it on both PCI and magnetic loops. Repeat shot at higher power, perhaps can get another 0.3 MW out of the E tube. |
| Mar 18 2004 01:47:52:217PM | 1040318020 | Miklos Porkolab | Increased pre-puff all the way to where we were this morning. Repeat shot at higher power, perhaps can get another 0.3 MW out of the E tube. Fizzle. Rrepeat again. |
| Mar 18 2004 02:03:44:540PM | 1040318021 | Miklos Porkolab | Increased pre-puff all the way to where we were this morning. Repeat shot at higher power, perhaps can get another 0.3 MW out of the E tube. Good shot, power up to 2.3 MW, steady from 0.08 sec to 0.15 sec, then drops out by 0.22 sec. See Alfven wave cascades from 0.12 to 0.15 sec. Also get ELMS(!) from 0.17 to 0.22 sec. Current ramp seems to be faster, up to 0.9 MA in 200 msec. |
| Mar 18 2004 02:24:51:400PM | 1040318022 | Miklos Porkolab | Increased pre-puff all the way to where we were this morning. Repeat shot at higher power, perhaps can get another 0.3 MW out of the E tube. Good shot, power up to 2.5 MW, steady from 0.08 sec to 0.13 sec, then drops out by 0.13, recovers at 0.18 sec. See Alfven wave cascades from 0.12 to 0.15 sec, but spectrum is weak, need more power, but cannot get it.. Current ramp seems to be faster, up to 0.9 MA in 200 msec. ----------------------------------------------------------- The run is transferred over to mini- proposal 300, running at 4.5Tesla, with off-axis RF on. martin Greenwald becomes Session Leader. |
| Mar 18 2004 03:20:37:157PM | 1040318024 | Martin Greenwald | Similar to shot 12 from 1040311 (as intended) possible weak ITB which is quenched when the field is raised |
| Mar 18 2004 03:29:03:733PM | 1040318025 | Martin Greenwald | final field lowered to 4.8 T but no obvious ITB |
| Mar 18 2004 04:06:49:807PM | 1040318026 | Martin Greenwald | Larger range for Bt ramp ITB that comes and goes looks like there is not much hysteresis |
| Mar 18 2004 04:22:50:470PM | 1040318027 | Martin Greenwald | Too much field ramp maybe weak itb need to look at vb profiles |
| Mar 18 2004 04:39:46:310PM | 1040318029 | Martin Greenwald | ITB til about 1.3 seconds Bt reached 4.8 T |
| Mar 18 2004 04:48:41:870PM | 1040318030 | Martin Greenwald | Field ramp reversed ITB begins at about 1.1 second Bt = 4.65 |
| Mar 18 2004 05:00:37:560PM | 1040318031 | Martin Greenwald | Similar to last shot rising Bt goes into ITB at 1.15 sec 4.6 T |
| Physics Operator Comments | |||
| Mar 18 2004 09:18:04:310AM | Dmitri Mossessian | MP#324A ITB Formation with Two-Frequency ICRF in Optimized Shear Plasmas with Ip Ramp Session leader: M. Porkolab Physics operator: D. Mossessian ECDC overnight in D2 at 2e-4 Torr, stopping by 07:00. Bake at 60 C overnight as well. Run begins at 09:00 and ends at 17:00. Power Supplies as on 1040309029 A-coils 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) leave B-side upper as is Hybrid DISABLED (PG2) fill C-side with 30 psi D2 Hybrid enabled (PG3) Enable the following gate valves, assuming no vacuum problems: ECE, VUV, DNB Run plan: Post boronization recovery + MP324A. Load 1021025005. The shot is limited on the inner nose at around 0.2 - 0.24 sec. If this is not desirable, the necessary changes in configuration can be made during boronization recovery phase. A. 8 shots at 5.4 Tesla Ramp current and divert discharge as reference discharge. Apply 70 MHz power up to 1.0 MW at 0.100 sec, apply 80 MHz Power at 0.080 sec into discharge, up to 2 MW. After 4 shots, with at least 1 MW at each frequency, start to divert the discharge earlier than the nominal 0.22 -0.24 sec, while maintaining power; the goal is to delay sawteeth as much as possible, and maximize stored energy, or ITB, as well as the edge pedestal temperature; monitor ELMs and Alfven wave cascade; try to obtain Grand Alfven wave cascade; monitor with PCI as well as several magnetic loops to measure the n number of the cascade modes; B. 5 shots If obtain good target shot, with lots of cascades, increase power further at either or both frequencies and optimize shots for cascades and/or ELMs and /or stored energy or neutrons or ITB Also, move RF powers earlier to see if could delay sawteeth further; Move relative timing of RF powers (frequencies) also to achieve goal . C.. 5 Shots. Repeat at 5.7 T D. 5 Shots Repeat at 5.0 T E. 5 Shots Repeat at 4.6 T. | |
| Mar 18 2004 09:21:31:980AM | Dmitri Mossessian | Loaded 1021025005. Programed A-coil in segment 2 for normal operation. | |
| Mar 18 2004 09:32:25:037AM | 1040318005 | Dmitri Mossessian | Dud. PO fault - I forgot to load segment 1 from one of the recent shots. Seg 1 in 102... shot has 30 msec of prepuf. Next shot - load seg 1 from last shot from yesterday 1040317032. Changed PG4 to 15 msec from 17. |
| Mar 18 2004 09:53:21:320AM | 1040318006 | Dmitri Mossessian | Plasma. Startup is good. There is a large injection at ~0.07 sec that shows up as a dip in the current rise. It may be due to some arcing in E-port which comes up at that time. Next shot - no change. |
| Mar 18 2004 10:07:13:500AM | 1040318007 | Dmitri Mossessian | Plasma. Startup is good. Next shot - attempting to make plasma diverted earlier. Move CLEARIN and RXL rampup 0.05 sec early. CLEARIN first non-zero point 0.25 -> 0.2, RXL 0.35 -> 0.3 |
| Mar 18 2004 10:27:18:347AM | 1040318008 | Dmitri Mossessian | Plasma. Startup is good. Diverted at about .22 Next shot - move RXL rampup earlier, starting at 0.2 sec |
| Mar 18 2004 10:44:47:110AM | 1040318009 | Dmitri Mossessian | Plasma. Startup is good. A series of large injections starts at 0.35 and kills the H-mode. Next shot - move RXL and CLEARIN rampup even earlier. |
| Mar 18 2004 10:59:44:240AM | 1040318010 | Dmitri Mossessian | Plasma. Startup is good. Still diverted at .22 sec. Early rampup in CLEARIN does not help it getting diverted earlier - plasma still sits on inner nose up to 0.22 s. Next shot - Move first positive CLEARIN point later to .15 s. Moving RXL startup to 0. sec. Slow down current rampup to reach 0.9 sec at 0.3 (insrtead of 0.2 sec) |
| Mar 18 2004 11:22:53:933AM | 1040318011 | Dmitri Mossessian | Plasma. Startup is good. Still diverted at .22 sec Next - lower PG3 in segment 1 90 -> 50 V to get lower density during current ramp. |
| Mar 18 2004 11:34:57:857AM | 1040318012 | Dmitri Mossessian | Plasma. Next shot - no change. |
| Mar 18 2004 12:06:42:923PM | 1040318014 | Dmitri Mossessian | Plasma. Next shot - raise current at .1 sec to 65 kA to avoid discontinuity between seg 1 and 2. |
| Mar 18 2004 12:19:44:490PM | 1040318015 | Dmitri Mossessian | Plasma. There is still an injection at 0.1 sec which may be attributed to segment switch. Next shot - move RXL rampup start after 0.1 sec |
| Mar 18 2004 12:36:14:843PM | 1040318016 | Dmitri Mossessian | Plasma. Still bad at 0.1 sec Next shot - bring PG3 back up to 70 V in seg 1. |
| Mar 18 2004 12:43:12:413PM | 1040318017 | Dmitri Mossessian | Plasma. Still bad at 0.1 sec Next shot - bring PG3 back up to 100 V in seg 1. |
| Mar 18 2004 01:19:55:470PM | 1040318019 | Dmitri Mossessian | Plasma. 0.1 sec is OK. Disrupted at 0.34 during H-mode due to large injection. Next shot - no change |
| Mar 18 2004 01:33:46:463PM | 1040318020 | Dmitri Mossessian | Fizzle. No obvious reason Next shot - no change |
| Mar 18 2004 02:15:18:917PM | 1040318022 | Dmitri Mossessian | Plasma. Next - switch to MP300 - ITB hysteresis. Load shot 1040311012. Changed PG4 to 15 msec in seg 1. |
| Mar 18 2004 03:14:27:053PM | 1040318024 | Dmitri Mossessian | Plasma. Next - change Bt rampup between 0.6 and 1.5 sec. |
| Mar 18 2004 03:34:18:100PM | 1040318025 | Dmitri Mossessian | Plasma. Next - change Bt rampup between 0.6 and 1.5 sec to start from 4.5 instead of 4.6T |
| Mar 18 2004 03:55:30:523PM | 1040318026 | Dmitri Mossessian | Plasma. Next - change Bt rampup between 0.6 and 1.5 sec to start end at 5 T instead of 4.8 T |
| Mar 18 2004 04:35:46:163PM | 1040318029 | Dmitri Mossessian | Plasma. Next - reverse Bt ramp between 0.6 and 1.5 sec |
| Mar 18 2004 04:54:43:770PM | 1040318030 | Dmitri Mossessian | Plasma. Next - repeat |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:21:40:407AM | Test | Ok | Scanner Test |
| 2 | 08:31:23:570AM | Test | Ok | |
| 3 | 08:39:40:193AM | Test | Ok | |
| 4 | 08:46:59:130AM | Test | Ok | |
| 5 | 09:16:40:010AM | Plasma | Ok | |
| 6 | 09:43:04:173AM | Plasma | Ok | |
| 7 | 10:01:48:493AM | Plasma | Ok | |
| 8 | 10:15:28:547AM | Plasma | Ok | |
| 9 | 10:30:28:413AM | Plasma | Ok | |
| 10 | 10:50:53:460AM | Plasma | Ok | |
| 11 | 11:07:58:533AM | Plasma | Ok | |
| 12 | 11:24:12:747AM | Plasma | Ok | |
| 13 | 11:40:35:413AM | Plasma | Ok | |
| 14 | 11:55:17:890AM | Plasma | Ok | |
| 15 | 12:11:24:210PM | Plasma | Ok | |
| 16 | 12:25:53:593PM | Plasma | Ok | |
| 17 | 12:39:02:253PM | Plasma | Ok | |
| 18 | 12:53:31:603PM | Plasma | Bad | Breakers Pulled During Check |
| 19 | 01:10:23:753PM | Plasma | Ok | |
| 20 | 01:28:59:517PM | Plasma | Ok | |
| 21 | 01:45:29:400PM | Plasma | Ok | |
| 22 | 02:02:06:490PM | Plasma | Ok | |
| 23 | 02:18:48:953PM | Plasma | Bad | Breakers pulled during pulse |
| 24 | 03:05:36:540PM | Plasma | Ok | |
| 25 | 03:22:55:130PM | Plasma | Ok | |
| 26 | 03:37:36:137PM | Plasma | Ok | |
| 27 | 04:03:44:940PM | Plasma | Ok | |
| 28 | 04:17:49:463PM | Plasma | Bad | All breakers pulled just prior to the shot -BCP |
| 29 | 04:28:17:917PM | Plasma | Ok | |
| 30 | 04:42:31:220PM | Plasma | Ok | |
| 31 | 04:56:50:790PM | Plasma | Ok | |