| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Kirill Zhurovich |
| Physics operator(s): | Ron Parker |
| Engineering operator(s): | Andy Pfeiffer,Bill Byford,Gary Dekow |
| Engineering Operator Run Comment |
| automatically entered by signon - please replace with real comment |
| Session Leader Plans |
| Entered: Jun 30 2005 12:23:45:403PM |
| Author: Kirill Zhurovich |
| MP#422 -- "ITB formation -- Ti critical gradient dependence"
The purpose of this experiment is to understand triggering mechanism for producing off-axis ICRF internal transport barriers. The question of whether ITB formation can be explained in the framework of suppressing ITG turbulence via increasing ion temperature scale length to the critical scale length is the target. This idea will be tested by varying Bt and thus shifting the RF resonance location on shot-to-shot basis. Required diagnostics: all standard core diagnostics, especially TS, ECE, HIREX, PCI +CHERS (if available) Set up GPC for 5.4T and GPC2 for 6.2T operation. ICRF - 80MHz, 3MW (or less, but fault-free and constant for all discharges). ICRF power will be adjusted during first plasma shots. Bt, Ip scan: Bt Ip 5.4 0.9 5.5 0.917 5.6 0.933 5.7 0.95 5.8 0.967 5.9 0.983 6.0 1.0 6.1 1.017 6.2 1.033 6.3 1.05 First, establish good equilibrium with long and steady H-mode. 1031218017 is a good candidate. Then start Bt scan with 0.2T increment, filling the gaps later in the day as time allows. |
| Physics Operators Plans |
| Entered: Jun 30 2005 03:18:57:580PM |
| Author: Ron Parker |
| Run Plan for Friday, July 1, 2005
MP#422 ITB Formation SL: Kirill Zhurovic PO: Ron Parker Run BEGINS @ 09:00 and ENDS @ 17:00 Overnight Boronize, then 4 hours of He discharge cleaning and 1 hour of D2 discharge cleaning Power systems as on 1050630 A-coil in standard configuration (+Dtop -Dbot -Jtop +Jbot) C-coil Start=0.3sec, Invert=2.0sec ICRF in Run-on condition by 8:30 AM Gas setup: fill B-top 6psi D2 Hybrid Enabled (PG4) fill B-side lower 1psi Argon Hybrid Enabled (PG1) leave B-side Upper alone Hybrid DISABLED (PG2) fill B-main 40psi D2 Hybrid Enabled (PG3) Enable: ECE, VUV, Z-bolo shutter Run Plan: First, several shots will be run for boronization recovery and RF tuning. The goal is to achieve a long, steady H-Mode at 0.9 MA and BT = 5.4 T. The SL suggests shot 1031218017 as a starting shot. This will require dealing with offsets and will need Steve Wolfe's help. Then, the field will be scanned in 0.1 T increments from 5.4 T to 6.3 T while maintaining constant q. |
| Session Leader Summaries |
| Entered: Jul 5 2005 12:33:47:997PM |
| Author: Kirill Zhurovich |
| The idea of this run was to put RF resonance on axis with 80MHz, 5.4T setup and then by increasing Bt to 6.2T move the resonance off-axis. The latter is the condition at which we had ITBs in the past.
This run required "good boronization", which was done before the run. We spent first several shots trying to condition ICRF to make it steady. RF became acceptable by shot 8-10. We were able to produce long H-modes. Interestingly enough none of them was steady, at least as far as nl time trace is concerned. Usually, the density continued to rise during H-mode phase, but sometimes there were ups and downs. A few shots later we started struggling with the radiation, so we started having back transitions with 2 H-modes first and multiple H-modes by the end fo the day. So, by the time we reached ITB conditions RF got worse and we were overwhelmed by the radiation. Having Boron shaker helped a bit, but still we were unable to get any ITBs even at the plasma parameters we used in the past. Overall unsuccessful run. Resume: we should have probably started with the ITB conditions and then gradually moved away from them. |
| Physics Operator Summaries |
| Entered: Jul 1 2005 05:29:46:980PM |
| Author: Ron Parker |
| The purpose of the run was to explore threshold conditions for ITB formation.
Unfortunately, no ITB's were formed even though the field and current were scanned over a range that has in the past produced ITB's with heating tuned to R > Rcur, e.g., 6.2-6.3 T. Next time this miniproposal is implemented, we should start in an ITB mode at the beginning of the run after boronization and move the resonance to the axis, rather than starting on axis and moving out. This run came right after an overnight boronization and the effect of the boronization in reducing radiated power seemed to have dissipated by the time ITB conditions were established. The machine ran very well with a robust startup for the entire run. There were 34 shots of which there were no fizzles nor any duds. There were however 3 disruptions. The remaining 31 shots were all full length, with current rampdowns to 100 kA or less. There no problems with the data system nor any equipment failures. |
| Session Leader Comments | |||
| Jul 1 2005 09:16:41:467AM | 1050701001 | Kirill Zhurovich | Plasma till 0.29s |
| Jul 1 2005 09:42:55:937AM | 1050701002 | Kirill Zhurovich | H-mode at ~0.7-1.2s, however RF tripped at ~0.9s
|
| Jul 1 2005 09:45:46:843AM | 1050701003 | Kirill Zhurovich | L-mode
RF < 1MW |
| Jul 1 2005 10:05:32:157AM | 1050701004 | Kirill Zhurovich | H-mode for ~1.1-1.4s
RF is still less than 1MW |
| Jul 1 2005 10:15:49:577AM | 1050701005 | Kirill Zhurovich | No H-mode
RF is still less than 1MW |
| Jul 1 2005 10:40:01:780AM | 1050701006 | Kirill Zhurovich | H-mode
RF is better |
| Jul 1 2005 10:50:56:327AM | 1050701007 | Kirill Zhurovich | H-mode
Similar to previous shot, unfortunately, RF trips at ~1.2s |
| Jul 1 2005 11:01:10:220AM | 1050701008 | Kirill Zhurovich | H-mode
RF is much better now, even >3MW with steady portion at ~0.9-1.3s |
| Jul 1 2005 11:08:43:843AM | 1050701009 | Kirill Zhurovich | Great shot
H-mode RF is ~ 3.5MW and steady for ~1-1.45s |
| Jul 1 2005 11:26:11:203AM | 1050701010 | Kirill Zhurovich | Great shot
H-mode RF is ~ 3.2MW and steady for ~0.7-1.5s Next: move on to 5.6T and 0.933MA |
| Jul 1 2005 11:31:55:703AM | 1050701011 | Kirill Zhurovich | Plasma till 0.3s
|
| Jul 1 2005 11:55:42:407AM | 1050701012 | Kirill Zhurovich | Good shot, but no ECE
repeat |
| Jul 1 2005 12:10:48:827PM | 1050701013 | Kirill Zhurovich | Good shot, but no ECE again!
repeat |
| Jul 1 2005 12:22:51:297PM | 1050701014 | Kirill Zhurovich | Good shot.
Bt=5.6, Ip=0.938, RF=3.15 Next: 5.8T |
| Jul 1 2005 12:41:09:327PM | 1050701015 | Kirill Zhurovich | Good shot.
Bt=5.8, Ip=0.968, RF=3.2 but RF faults at t>1.2s repeat |
| Jul 1 2005 12:51:42:890PM | 1050701016 | Kirill Zhurovich | Good shot.
Bt=5.8, Ip=0.968, RF=3.1 but RF frips at 1.25s causing H-L transition As a result 2 H-modes: 1st for 0.3s, 2nd for ~0.15s and not steady Next: 6T |
| Jul 1 2005 01:07:11:437PM | 1050701017 | Kirill Zhurovich | Good shot.
but Bt was only 5.93T while the current was 1MA Cause: current limit for TF coils. Next: raise that limit and go for 6T |
| Jul 1 2005 01:18:07:110PM | 1050701018 | Kirill Zhurovich | Bt=5.98, Ip=1, RF=3.15
RF trips againg after t=1.18 We are having shorter and shorter steady RF periods. Next: stay at this field and condition the antenna |
| Jul 1 2005 01:26:00:593PM | 1050701019 | Kirill Zhurovich | 4 H-modes - RF conditioning
Next: go back to 3MW repeat 6T |
| Jul 1 2005 01:44:53:983PM | 1050701020 | Kirill Zhurovich | Rf trips again at t.1.18s + a couple of faults around .85s
Might be a problem with right gap |
| Jul 1 2005 01:56:54:920PM | 1050701021 | Kirill Zhurovich | 2 H-modes with H-L transition at around 1.15s
Need to move on. Next: 6.1T, should expect ITB |
| Jul 1 2005 02:12:05:250PM | 1050701022 | Kirill Zhurovich | 2 H-modes with H-L transition at around 1s
No density peaking. Next: go up to 6.2T, we need to get ITB |
| Jul 1 2005 02:26:37:233PM | 1050701023 | Kirill Zhurovich | 2 H-modes with H-L transition at around 1s. Current was lower than should be.
No density peaking. Next: 6.2T and 0.8MA to see if we can get an ITB at all. |
| Jul 1 2005 02:44:03:640PM | 1050701024 | Kirill Zhurovich | No TS.
3 H-modes. Some chance that there is peaking during 1st H-mode. Actually, on march 10, 2004 we had ITB at 6.45T and 1.2MA, so having Ip around 1MA should not be a problem. Next: go back to the original plan. 6.3T, 1.05MA and raise the target density to 1.1(per Steve Wukitch). |
| Jul 1 2005 02:52:47:187PM | 1050701025 | Kirill Zhurovich | 3 H-modes (with a few H-L subtrunsitions, not steady)
Target density is below 1. Next: raise the target density to 1.1; same field and current |
| Jul 1 2005 03:14:31:047PM | 1050701026 | Kirill Zhurovich | 4 H-modes (with a few H-L subtrunsitions, not steady)
It's getting worse. Let's try to step back and see if we can repeat shot 14 |
| Jul 1 2005 03:34:42:703PM | 1050701027 | Kirill Zhurovich | 2 H-modes
RF is better. We really need to find an ITB. Next: 6.45T, 1.075MA, target density=1.2 |
| Jul 1 2005 03:52:24:687PM | 1050701028 | Kirill Zhurovich | 2 H-modes again.
Radiation is high. Next: raise the target density by another 10% |
| Jul 1 2005 04:49:00:640PM | 1050701029 | Kirill Zhurovich | L-mode; we crossed the neutrals pressure limit for RF.
Next: 1)cut back on target density to 1.2 2)Try boron injector. |
| Jul 1 2005 04:19:56:360PM | 1050701030 | Kirill Zhurovich | 2 H-modes with more than 0.2s in between...
Radiation is lower. Next: increase lower triangularity |
| Jul 1 2005 04:23:52:717PM | 1050701031 | Kirill Zhurovich | Disruprion at ~0.75s (H-mode) |
| Jul 1 2005 04:49:25:060PM | 1050701032 | Kirill Zhurovich | 2 H-modes.
RF trips but recovers after the second H-mode (but no third H-mode!) Next: try to increase inner gap from 1cm to 2cm to better mimic 1040310010 |
| Jul 1 2005 05:02:11:110PM | 1050701033 | Kirill Zhurovich | 2 H-modes.
The second one is pretty long, density rises but no peaking :( H-alpha looks like EDA, QC is there but broad and at higher (300KHz) frequency Next: increase outer gap a little bit. Decrease RF by 200KW |
| Jul 1 2005 05:20:13:203PM | 1050701034 | Kirill Zhurovich | 2 H-modes.
no peaking. second H-mode is Rf-induced but Ohmic later |
| Physics Operator Comments | |||
| Jul 1 2005 09:21:18:060AM | 1050701001 | Ron Parker | We are using startup from 1050525002 (segment 1) followed by
segment 2 from 1031218017. First shot started well, but disrupted at 0.3 s. Try again, no changes. |
| Jul 1 2005 09:41:35:263AM | 1050701002 | Ron Parker | Shot 2 ran well, as programmed. ip ~ 900 kA, H-mode, n_eL(4) ~ 2e20 m-2.
SL wants to stay here a while with this shot. |
| Jul 1 2005 09:50:06:733AM | 1050701003 | Ron Parker | Shot 3 ran well, however RF power too low for H-mode.
Continue running this shot, lower fill pressure by 2 ms. |
| Jul 1 2005 10:01:02:593AM | 1050701004 | Ron Parker | Shot 4 ran OK, an injection of something occured around .65 s, but shot recovered.
Short H-mode. |
| Jul 1 2005 10:21:19:343AM | 1050701005 | Ron Parker | Shot 5 again ran well, Rf power still at 1 MW level (but steady). |
| Jul 1 2005 10:32:18:030AM | 1050701006 | Ron Parker | Shot 6 was an improvement -- Steady H-mode, RF power ~ 2.6 MW.
SL wants 3 MW, so we'll stick with this shot. |
| Jul 1 2005 10:43:06:890AM | 1050701007 | Ron Parker | We're getting there, RF power is 3 MW on that shot although
there are a few trips. Effect of Ninja puff will be determined by shutting it off for next shot. |
| Jul 1 2005 11:05:49:093AM | 1050701008 | Ron Parker | Good shot, RF at 3 MW steady from 1 to 1.3 s.
Breakdown moving over 5 ms, reduce gas prefill by 2 ms for next shot. |
| Jul 1 2005 11:06:37:360AM | 1050701009 | Ron Parker | Shot 9 looked good, RF power over 3 MW, only two short trips. |
| Jul 1 2005 11:28:42:123AM | 1050701010 | Ron Parker | Shot 10 looked fine, steady RF at 3 MW, no trips.
That's it for this field. Now we'll increase the TF from 5.4 to 5.6 (not 5.5 as in run plan) and 933 kA. |
| Jul 1 2005 11:38:51:577AM | 1050701011 | Ron Parker | Shot 11 disrupted at ~ 0.3 s. Reason not clear. |
| Jul 1 2005 11:57:39:047AM | 1050701012 | Ron Parker | Shot 12 ran OK, density was not steady during H-mode, although RF
had only one trip. Run shot again. Bz(0) looks a bit too positive, decrease EF4 by 5 A to -1315. One of teh GPC's needs attention, short delay. |
| Jul 1 2005 12:11:39:763PM | 1050701013 | Ron Parker | Shot 13 was good, steady RF at 3 MW and nearly constant density.
Unfortunately, GPC gate valve did not open so we'll repeat. Also, breakdown came back to less than 5 ms with decrease of EF4 current to -1315 A. |
| Jul 1 2005 12:25:03:703PM | 1050701014 | Ron Parker | Shot 13 was good. We'll move on to 5.8 T and 0.967 kA for next shot. |
| Jul 1 2005 12:43:30:360PM | 1050701015 | Ron Parker | Shot 15 ran well, but RF faulted several times toward teh end of shot.
We'll repeat and reduce outer gap by ~ 2 mm per Steve W.'s suggestion. |
| Jul 1 2005 12:53:01:873PM | 1050701016 | Ron Parker | Shot 16 had a problem around 1.27 s. But we'll go on to 6 T and 1.0 MA
for shot 17. |
| Jul 1 2005 01:06:01:500PM | 1050701017 | Ron Parker | Shot 17 was a good one, but field didn't quite reach 6 T due to
engineering current limit set at 165 kA. We'll repeat. |
| Jul 1 2005 01:18:58:843PM | 1050701018 | Ron Parker | shot 18 was OK except for some RF trips beginning at 1.18 s.
Next: Repeat with slight increase of RF power. |
| Jul 1 2005 01:36:41:810PM | 1050701019 | Ron Parker | Shot 19 ran OK, but RF was intermittent.
Try again with RF back to 3 MW. |
| Jul 1 2005 01:43:12:110PM | 1050701020 | Ron Parker | Shot 20 ran well, RF still having problems with trips.
We'll increase outer gap by 2 mm for next shot. |
| Jul 1 2005 01:59:30:187PM | 1050701021 | Ron Parker | Shot 21 went off OK. We are moving to 6.1 T and 1.017 MA on next shot. |
| Jul 1 2005 02:22:55:403PM | 1050701022 | Ron Parker | Shot 22 looked OK, RF still tripping.
Next: 6.2 T. Current still at 1.017 MA |
| Jul 1 2005 02:23:50:827PM | 1050701023 | Ron Parker | Shot 23 ran well. One Rf trip and 2 H-modes.
For next shot, we'll reduce current to 0.8 MA (looking for ITB's) |
| Jul 1 2005 02:46:39:937PM | 1050701024 | Ron Parker | Shot 24 ran OK. No clear ITB.
Next: 6.3 T, 1.05 MA |
| Jul 1 2005 02:50:15:500PM | 1050701025 | Ron Parker | Shot 25 ran OK, several H-modes, although RF tripped only once up to 0.3 s. |
| Jul 1 2005 03:08:24:060PM | 1050701026 | Ron Parker | Shot 26 ran well, intermittent H-modes. Radiation seems high
according to 2pi bolometer. |
| Jul 1 2005 03:11:07:907PM | 1050701026 | Ron Parker | Machine conditions seem to be degrading. We'll return to earlier
good shot, 1050701014 to compare |
| Jul 1 2005 03:28:13:797PM | 1050701027 | Ron Parker | Shot 27 ran OK, but the 2pi bolometer indicates higher radiated power than
for shot 14 today, 3 MW vs. 2.5 MW; H-mode intermittent although RF is steady. |
| Jul 1 2005 03:47:46:687PM | 1050701027 | Ron Parker | We'll continue to push up on the field: 6.45 T, 1.075 MA, target density
1.2e20 m-2. |
| Jul 1 2005 03:42:25:467PM | 1050701028 | Ron Parker | Shot 28 ran as programmed, reaching 1.07 MA and 6.4 T |
| Jul 1 2005 04:00:49:547PM | 1050701029 | Ron Parker | Shot 29 ran, but no H-mode as pressure at one of the antennas was too high.
We're returning the target density to 1.2e20 m-2 and will try boron shaker reduce radiation. |
| Jul 1 2005 04:13:35:750PM | 1050701030 | Ron Parker | Shot looked better, but H-mode dropped out at ~ 1.1 s. Radiated power seemed
to be lower before the RF/H-mode trip. |
| Jul 1 2005 04:32:11:530PM | 1050701031 | Ron Parker | Shot 31 disrupted at 0.76 s. Too much boron? Try again, less boron. |
| Jul 1 2005 04:48:42:547PM | 1050701032 | Ron Parker | Shot 32 ran OK. Less radiated power, but still drops out of H-mode. Also RF trips.
Next: Increase outer gap by 1 cm (Also Rcur increased by 5 mm to keep outer gap constant.) |
| Jul 1 2005 04:58:08:907PM | 1050701033 | Ron Parker | Shot 33 actually looked a little promising. Prolonged H-mode from 1 to 1.5 s
but RF partially trips in second H-mode. Next: Same, except outer gap opened up ~ 0.4 cm toward end of shot. |
| Jul 1 2005 05:10:24:610PM | 1050701034 | Ron Parker | Shot ran OK, first H-mode from 0.65 to 1.1 s when 2pi bolometer
indiccates full radiative loss. H-mode turns back on just before current inversion even though RF power stays on for the full pulse (at slightly reduced power). No sign of ITB. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:10:03:373AM | Plasma | Ok | |
| 2 | 09:29:26:843AM | Plasma | Ok | |
| 3 | 09:42:14:123AM | Plasma | Ok | |
| 4 | 09:56:08:890AM | Plasma | Ok | |
| 5 | 10:11:49:060AM | Plasma | Ok | |
| 6 | 10:24:11:483AM | Plasma | Ok | |
| 7 | 10:36:58:263AM | Plasma | Ok | |
| 8 | 10:49:19:873AM | Plasma | Ok | |
| 9 | 11:01:45:513AM | Plasma | Ok | |
| 10 | 11:14:27:047AM | Plasma | Ok | |
| 11 | 11:28:33:577AM | Plasma | Ok | |
| 12 | 11:42:41:437AM | Plasma | Ok | |
| 13 | 12:00:58:280PM | Plasma | Ok | |
| 14 | 12:13:27:797PM | Plasma | Ok | |
| 15 | 12:25:58:453PM | Plasma | Ok | |
| 16 | 12:41:04:437PM | Plasma | Ok | |
| 17 | 12:53:48:140PM | Plasma | Ok | |
| 18 | 01:07:40:530PM | Plasma | Ok | |
| 19 | 01:20:26:390PM | Plasma | Ok | |
| 20 | 01:33:05:310PM | Plasma | Ok | |
| 21 | 01:45:44:450PM | Plasma | Ok | |
| 22 | 01:59:41:983PM | Plasma | Ok | |
| 23 | 02:13:14:437PM | Plasma | Ok | |
| 24 | 02:25:51:360PM | Plasma | Ok | |
| 25 | 02:43:12:233PM | Plasma | Ok | |
| 26 | 02:58:03:920PM | Plasma | Ok | |
| 27 | 03:15:32:717PM | Plasma | Ok | |
| 28 | 03:35:41:560PM | Plasma | Ok | |
| 29 | 03:51:50:717PM | Plasma | Ok | |
| 30 | 04:06:51:157PM | Plasma | Ok | |
| 31 | 04:20:31:140PM | Plasma | Ok | |
| 32 | 04:33:11:360PM | Plasma | Ok | |
| 33 | 04:47:59:640PM | Plasma | Ok | |
| 34 | 05:02:52:937PM | Plasma | Ok | |