| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Amanda Hubbard |
| Physics operator(s): | Ian Hutchinson |
| Engineering operator(s): | Sam Pierson,Andy Pfeiffer,Ed Fitzgerald |
| Engineering Operator Run Comment |
| MP 615: Access to I-mode regime with favorable magnetic drift EO Pierson |
| Session Leader Plans |
| Entered: Aug 26 2010 02:37:34:987PM |
| Author: Amanda Hubbard |
| Run plan for 1100827
MP 615: Access to I-mode regime with favorable magnetic drift Session leader: Amanda Hubbard Physics operators: Ian Hutchinson and David Pace Critical diagnostics include ETS, ECE, DNB with CXRS, GPI, PCI, fast magnetics and reflectometry. 1. Repeat 1090902032 (5.4 T, 800 kA, grazing incidence shape, RF power ramp). Try to reproduce I-mode. 4 shots. If successful, then (otherwise go to 3): 2. Use constant ICRF power at varying levels, to find the power threshold for I-mode, and the max power to stay out of H-mode. Also get better profiles, fluctuations (including CXRS with DNB). 4 shots. 3. Shape variation. Scan x-point, strike point locations shot to shot, trying to obtain I-mode if absent in step 1, or find accessible configuration space if present. In particular, vary Dsep â?? distance to inner nose - which may be a critical parameter . Ramp ICRF to 3 MW on each discharge to be sure to reach threshold. 10 shots. 4. Return to Step 1 shape, or another if I-mode seems more robust there. Scan current, to extend threshold and pedestal studies. (USN scans have consistently shown both PL-I and pedestal T and confinement increasing with Ip). 0.9 MA, 1.0 MA, 1.1 MA (to max available, which may be limited by supplies in this shape). Use power ramp to bracket threshold, then repeat with a constant power near upper limit. If sawteeth are triggering H-modes at low q95, slightly raise Bt (5.7 T) to reduce heat pulses. 6 shots. 5. Progressively increase elongation and modify triangularities, moving towards more typical C-Mod shape (k=1.6), to determine range over which I-mode can be obtained. This should also add information about which shape parameters are key to obtaining LSN I-modes. 10 shots. Plan B: If no I-modes have been obtained by early afternoon, we may switch to upper null, 1.3 MA I-modes as attempted on 1100817, eg shot 29. |
| Physics Operators Plans |
| Entered: Aug 26 2010 06:46:55:853PM |
| Author: |
| PO Plan for 11008027
MP 615 - Access to I-mode regime with favorable magnetic drift PO/APO: I. Hutchinson / D. Pace ----------------- Engineering Setup ----------------- Run begins at 09:00 and ends at 17:00 There will be overnight ECDC. Power systems as on: 1090902032 Acoil: +Dtop -Dbot -Jtop +Jbot (standard) Hybrid Enabled Gas setup: Fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar Hybrid DISABLED (PG1) leave B-side upper as is Hybrid DISABLED (PG2) fill B-main (C-side) with 40 psi D2 Hybrid enabled (PG3) fill NINJA with 10 psi D2 DISABLED Enable gate-valves and shutters: ECE, VUV, HiREX Sr, Xeus Leave z-bolo shutter as is (should be open) Torvac gatevalve toggle (yes/no): no Boronization(yes/no): no Overnight ECDC (yes/no): YES ICRF(yes/no): YES LH(yes/no): no Cryopump (yes/no): YES, ready for the first shot DNB (yes/no): YES Vessel temperature: 35/35/35 ------------------------------ ECDC Parameters (if requested) ------------------------------ gas and pressure: D2 at 2e-4 Torr sweep: 44/45/103 cm scan: 20/120 s First Shot: Will begin with settings from 1100826032, and then make the following changes: - ensure fill gas puff is at 50 ms to account for cryopump - import segment 2 from 1090902032 |
| Entered: Aug 26 2010 06:46:56:557PM |
| Author: |
| PO Plan for 11008027
MP 615 - Access to I-mode regime with favorable magnetic drift PO/APO: I. Hutchinson / D. Pace ----------------- Engineering Setup ----------------- Run begins at 09:00 and ends at 17:00 There will be overnight ECDC. Power systems as on: 1090902032 Acoil: +Dtop -Dbot -Jtop +Jbot (standard) Hybrid Enabled Gas setup: Fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar Hybrid DISABLED (PG1) leave B-side upper as is Hybrid DISABLED (PG2) fill B-main (C-side) with 40 psi D2 Hybrid enabled (PG3) fill NINJA with 10 psi D2 DISABLED Enable gate-valves and shutters: ECE, VUV, HiREX Sr, Xeus Leave z-bolo shutter as is (should be open) Torvac gatevalve toggle (yes/no): no Boronization(yes/no): no Overnight ECDC (yes/no): YES ICRF(yes/no): YES LH(yes/no): no Cryopump (yes/no): YES, ready for the first shot DNB (yes/no): YES Vessel temperature: 35/35/35 ------------------------------ ECDC Parameters (if requested) ------------------------------ gas and pressure: D2 at 2e-4 Torr sweep: 44/45/103 cm scan: 20/120 s First Shot: Will begin with settings from 1100826032, and then make the following changes: - ensure fill gas puff is at 50 ms to account for cryopump - import segment 2 from 1090902032 |
| Entered: Aug 26 2010 06:49:53:587PM |
| Author: |
| Addendum:
Will also change the fizzle detector off time to 2.1 s (this is set at 1.8 s on the SL reference shot). |
| Entered: Aug 27 2010 08:11:01:290AM |
| Author: Ian Hutchinson |
| This is a test of the strange logbook behavior. The plan for today is to
let David Pace do the Physop Entries under my supervision. The start of today is blown away by the fact the computer system disks are somehow broken. |
| Session Leader Summaries |
| Entered: Aug 27 2010 05:44:31:403PM |
| Author: Amanda Hubbard |
| Session leader summary for 1100827
MP 615: Access to I-mode regime with favorable magnetic drift Session leader: Amanda Hubbard Physics operators: Ian Hutchinson and David Pace This was a very successful run day. We essentially followed the run plan, through step 4 (of 5) and learned a number of new things. 1. The "I-mode" in lower null, favorable drift, which had previously been encountered only fortuitously in a couple of 2009 shots, can be reproduced. In most cases it is a transient phase preceding an ELMy H-mode. A 'weakly coherent mode' is exhibited, and typically there is a gradual increase of density through the I-mode to the H-mode (ie a weak particle barrier?) making the transition of regimes hard to distinguish from ne traces. However, the changes in fluctuations are very clear. 2. The shape used in 1090902032 is close to optimal. A shape scan, varying R of the x-point, was carried out at 800 kA shots 5-18. With the plasma on the nose, signatures of I-mode are lost, we get only a prompt H-mode, no transient I-mode. With larger R, the transient phase is still there but reduced (and ELMs get huge, eg shot 16. Perhaps the biggest surprise of the day was that in one shape, close to grazing with the outer strike point above the slot, we see I-mode like changes in fluctutions (drop in mid-f, increase at high -f, and modest changes in Dalpha, ne, Te) BEFORE the RF. in the ohmic period. This was first noticed on shot 11, and reproduced on shot 17. When the RF is turned on the turbulence evolves smoothly into classic WCM- perhaps this is a strong clue as to why these shapes favors I-mode. For Shot 18 was ohmic, with a shape scan to help us track the key parameters. For threshold scans, shots 19 on, we used the shape of shot 12. 3. LSN I-mode exists in a restricted power window. While we didn't establish a lower bound, the upper bound is set by the I-H mode transition which as previously found is quite low. At 800 kA, we could use up to 700 kW ICRF, and at 1 MA only 300 kW. This is a double-edge sword; it is easy to access, but global performance is not great; note we have previously found that H98 scales with input power in I-mode. In USN this can be quite high and scales with Ip, this doesn't appear the case in lower null. 4. Below this power threshold, I-mode can be extended to (near) steady state, ie several hundred ms. Best examples today are: 800 kA: shots 22, 30 1 MA: Shot 29. Note that shot 26, with higher, ramped power, had an extended I-mode period and a much stronger, more coherent mode so is also of interest. Thanks very much to all who contributed, in particular able physops David Pace and Ian Huthinson who avoided fizzles all day and circumvented the nasty injections from the inner wall, Yijun Lin for tailoring ICRF power on demand, Jerry Hughes for able back-seat driving and all diagnostics folks. Anne White reports the 'weakly coherent mode' on FRCECE, at least when Bt was increases from shot 26 on. |
| Physics Operator Summaries |
| Entered: Aug 27 2010 05:10:24:650PM |
| Author: David Pace |
| Problem with injections from inner wall on first few shots. This was also encountered during the previous day's run. The solution yesterday was to keep the plasma slightly higher than desired for a short time. That worked for shot 2 today, but was insufficient in shot 3. The gas of PG3 was extended to further combat this issue. The normal turn-off of PG3 was replaced with a flattop of amplitude 50 between 0.01 - 0.10 s. See the PULSE_GAS3 wire in segment 4 os shot 1100827030 for an example.
The inner wall problem appears to be related to a misaligned tile. This tile is clearly seen heating up in WIDE2 videos. Run Delays -- During shot 10, there was odd behavior in the power supplies. OH2L appears to have taken some significant current due to a crowbar firing. The Engineering team investigated the problem during a cell access and determined that no action was required. A full plasma was achieved on the subsequent shot. There was a general addition of a few minutes to the Recool phase through out the day. Coil cooling is slower than usual, which results in an extended period between shots. |
| Session Leader Comments | |||
| Aug 27 2010 09:08:51:873AM | 1100827001 | Amanda Hubbard | Early disruption (0.25 s) apparently due to a hot spot on the inner wall; big injection 0.2 s. |
| Aug 27 2010 09:45:49:447AM | 1100827002 | Amanda Hubbard | Full shot, with shape and density closely resembling our target. ELMs, and Arturo reports interesting fluctuations. Low RF power; retune and retry.
There is a fluctuation feature on the magnetics at 200-300 kHz. Edge Te not very high (400 eV on GPC 8 at r/a 0.91), but there was only 0.5 MW RF power. Seems we have a *possible* I-mode. nel 0.64-0.75e20, matches target shot well down to the dip at 0.8 s. |
| Aug 27 2010 09:46:18:177AM | 1100827003 | Amanda Hubbard | Early disruption - inner wall tile bit us again. |
| Aug 27 2010 10:23:46:540AM | 1100827004 | Amanda Hubbard | Full length and interesting shot. Clean RF ramp to 3 MW.
Looks like a prompt H-mode (nel rises 6.64 to 1.0e20 m-3). At 0.9 s, a fluctuation comes in and ne clamps; even drops after about 1.2 s. QCM or WCM? Next shot: drop target ne, and use constant RF 1 MW. |
| Aug 27 2010 11:45:14:210AM | 1100827005 | Amanda Hubbard | Good - constant 1 MW ICRF, lower target. ELMy H-mode!
L-H at 0.83 s, soon after RF on. Close inspection shows a transient HF feature in the evolution phase after this, and a cohererent triplet 300-400 kHz during the ELM-free period. Big ELMs start 0.884 s. Seem to coexist with a QC mode ~ 100 kHz. Next: move ETS fibres for better pedestal coverage, and shift x-point inboard a bit in search of I-mode. |
| Aug 27 2010 11:37:40:233AM | 1100827006 | Amanda Hubbard | X-point moved in. Still looks like a prompt H-mode, though ELMs are much smaller and delayed. Hint of a high-f fluctuation before the L-H, but its very transient.
Next: repeat with argon for John. |
| Aug 27 2010 10:56:56:900AM | 1100827007 | Amanda Hubbard | Repeat - slightly cooler edge due to argon, but phenomenology still the same - H-mode with ELMs 1.04-1.2 s. Clear QC mode before that. Note the ELMs disappear when ICRF steps up later in the flat top.
Clear ne and Te pedestals on the new ETS positions. |
| Aug 27 2010 11:13:25:473AM | 1100827008 | Amanda Hubbard | With lower (0.6 MW) starting RF power, L-H transition is delayed a little to 0.83 s. Not a clear I-mode, though Te does rise and there are hints of fluctuations (200-300 kHz) before the L-H, and the L-mode broad-band fluctuations do notably decrease (50-200 kHz). Mainly H-modes, ELM-free followed by big ELMs. But also some back transitions, with HF fluctuations; is this L or I-mode?? Both QCM and higher f in the high power H-mode at the end.
Next shot: Delay ICRF, and reduce starting power in an attempt to stretch the pre-H-mode phase. |
| Aug 27 2010 11:17:17:830AM | 1100827009 | Amanda Hubbard | Early disruption; I presume the inner wall tile got us again. |
| Aug 27 2010 11:32:04:807AM | 1100827010 | Amanda Hubbard | Disrupts 0.9 secs, following a "really strange" PS issue at 0.811. |
| Aug 27 2010 12:20:13:913PM | 1100827011 | Amanda Hubbard | Interesting shot, full length.
RF on at 0.9 s, 0.3-1 secs as requested. This was to make sure the equilibrium was steady. Apparently it was not. Still get a dip in D-alpha, and slight rise in ne, at 0.78 secs. And, the reflectometer fluctuations change - with a drio 100-200 kHz and increase 200-250 khZ as is typical of I-mode. Once RF on, this strengthens and an L-H transition soon follow. Classic LH at 0.93 secs (HF feature strengthens first). ELMs at 0.94 s. Kind of an "ohmic I-mode", though Tedge does not rise appreciably due to lack of heating power. Te8 only 275 eV, vs 400 in H-mode. Next shot: Move x-point out a little. |
| Aug 27 2010 12:23:57:503PM | 1100827012 | Amanda Hubbard | Good shot. Moving x-point (and strike point) only a few mm eliminated the "ohmic I-mode" phase. Did get HF fluctuations from about 0.93 secs on, which drop at classic L-H transition (0.98 secs). So I think we have a transient I-mode phase, longer than on prior shots.
Still big ELMs in H-mode. Next: Move x-point out more. |
| Aug 27 2010 12:34:45:120PM | 1100827013 | Amanda Hubbard | x-point to slightly larger R, definitely not nose-limited now. Similar to shot 12; L-mode before RF, L-H at about 0.96 secs (earlier than shot 12) and a transient "I-mode/slow transition" phase 0.93-0.96 secs in which high-f fluctuation feature appears.
Still ELMs in H-mode, though a bit smaller, and clear fluctuations at both 150 and 280 kHz persisting through H-modes (modulated by ELMs). There may be a brief I-mode phase around 1.08 secs (HF feature, ne and Te drop) Next: Go to smaller x-pt radius than shot 11. (ie scan other way)/ |
| Aug 27 2010 12:40:41:723PM | 1100827014 | Amanda Hubbard | Early disruption - inner wall shower. |
| Aug 27 2010 01:16:06:067PM | 1100827015 | Amanda Hubbard | Inner nose limited. Delayed the L-H transition until 1.3 secs (RF still on at 0.9). But no sign of I-mode on either fluctuations (except maybe very briefly) or on edge Te which stays cold until L-H. Shape does matter for this!
Next, try increasing x-point R beyond that of shot 13. |
| Aug 27 2010 01:20:28:303PM | 1100827016 | Amanda Hubbard | A long way from nose-limited. Transition is similar to shots 12 and 13- no changes in ohmic phase, a slow transition/I-mode phase 0.924 to 0.96 and "H-mode" 0.96 s (0.49 MW power). These are consistent but not very exciting. It's hard to define exact transtion times as density evolution is quite continuous, though changes in fluctuations are evident.
Really big ELMs starting from 0.995; 100 eV drop in edge Te, and causes RF trips. Tedge 400 eV in both "I-mode" and H-mode. |
| Aug 27 2010 01:36:47:627PM | 1100827017 | Amanda Hubbard | Repeat shot 11 (near-grazing shape). Again, we get a change in turbulence, dalpha, Tedge and ne slightly before the RF (this time 0.86 s). So, it is reproducible!
After RF, a prompt L-H (or I-H?) transition. 0.93 secs, ELMy, with QC and HF modes. Next shot, turn off ICRF to see the ohmic behaviour more clearly. And sweep x-pt out after 1.2 secs to see the shape dependences. |
| Aug 27 2010 01:53:43:523PM | 1100827018 | Amanda Hubbard | Ohmic shot. We did indeed see "I-mode like" changes in the turbulence, the D-alpha and bolos, also Tedge though still cold, in the period from 0.8 s on, which reverted to "normal" around 1.27 secs when x-point was swept out. We'll have to examine to see just which shape variables are best correlated.
For now, back to the RF I-mode search. Repeat shot 12, which had the latest transition. Use constant ICRF 0.4 MW instead of a ramp, in hope of delaying the L-H. |
| Aug 27 2010 02:07:28:867PM | 1100827019 | Amanda Hubbard | Constant ICRF 0.4 MW as requested. Shape from shot 12.
This gave I-mode like fluctuations throughout, though there is a (weak) density pedestal. Not sure whether to call it I or H-mode. ELMy from 1.0-1.1 s. Te8 370 eV, highest in the ELMy period but not exactly smoking. Next shot: reduce density. (we are 6.5e19 at RF on, vs 0.65 on 1090902032 which got a lot hotter). |
| Aug 27 2010 02:23:23:440PM | 1100827020 | Amanda Hubbard | Lower ne - perhaps a bit too much. 0.4 MW. nel 0.55 - 0.6 e20 in IRCF (some kind of change around 1 sec). Arturo reports decrease in turbulence on 60 GHz channel - no change at 88 GHz. I-mode after all? Next shot ramp power up.
|
| Aug 27 2010 02:48:53:340PM | 1100827021 | Amanda Hubbard | Good. This is starting to resemble the 1090902 case - steady increase in Te (and to a lesser extent ne) until a delayed H-mode transition at 1.04. Then, ELMy. Te8 gets to 460 eV (about the same as in H-mode).
Next: Repeat with constant 700 kW RF. |
| Aug 27 2010 02:53:50:770PM | 1100827022 | Amanda Hubbard | Nice. Steady plasma (we think I-mode) in ICRF period at 700 kW. Certainly no H-mode transition, H98 0.86. nel about 0.7 e 20.
Clear WCM 250-200 kHz, stronger late in the pulse. So we can indeed make this regime steady in LSN, although at rather low powers. Should be a good shot for DNB CXRS. repeat with more RF power, and NINJA late in the flat period. |
| Aug 27 2010 03:06:05:247PM | 1100827023 | Amanda Hubbard | 1 MW ICRF, gave quite a prompt H-mode, with plenty of ELMs. Transient WCM/I-mode phase until 0.96 s.
Will return to 800 kW (slightly higher than shot 22). Hope to get CXRS from DNB and NINJA. |
| Aug 27 2010 03:32:17:660PM | 1100827024 | Amanda Hubbard | 0.8 MW - even this gave H-mode, delayed until about 1.01 s (later than shot 23, but unfortunately before NUNJA or DNB so we won't have I-mode).
Indications of sawtooth triggering (few ELMs at each pulse). I may want to revisit this one at higher Bt later. Given time, I will move on and try for higher Ip, which generally gives higher Tped (and in USN, higher Pthresh); Ian has talked me down from 1 MA to 0.9 MA. |
| Aug 27 2010 03:43:20:487PM | 1100827025 | Amanda Hubbard | 900 kA worked well. Got an ELMy H-mode by 1 sec, with perhaps some dithers earlier at sawtooth heat pulses.
Apparently supplies have headroom, so we will try 1 MA on the next shot. Also raise Bt to 5.6 T; to lower q95, decrease heat pulses and also shift FRCECE channels out. This will shift GPC channels too, so positions will not be comparable. But I think I'll leave them alone for now. |
| Aug 27 2010 04:14:13:247PM | 1100827026 | Amanda Hubbard | 1.0 MA, 5.55 T. Ramped RF.
A keeper: Nice I-mode period with a very clear mode (modulated by sawteeth) until 1.1 secs, 1 MW RF. Then an ELMy H-mode. GPC Ch 7 is now at r/a 0.95, and gets to 420 eV in I-mode, 500 in H-mode. nel 0.61 target, slow rise to 0.88 in I-mode, to 1.3 in H-mode. Martin's scope says H98 near 1 in I-mode and DROPS to about 0.7 in H-mode (as Prad, ne rise). Next: Steady 0.8 MW RF, try to extend I-mode and/or find I-H threshold. |
| Aug 27 2010 04:13:08:040PM | 1100827027 | Amanda Hubbard | 1.0 MA, 5.55 T. steady RF 0.9 MW.
This gave a quite prompt H-mode transition, by about 0.95 s, with only a brief I-mode/WCM period leading up to it. Next: repeat with lower RF power. |
| Aug 27 2010 04:35:49:850PM | 1100827028 | Amanda Hubbard | 1.0 MA, 5.55 T. steady RF 0.5 MW.
Still get an H-mode, at about 1 second. There's a WCM/I-mode before that, but the mode is much weaker and less coherent than on shot 26. Apparently I-H mode threshold does not increase with Ip as in USN. Ah well, that's part of the experiment. Try even less power - we're getting close to ohmic though... Yet ohmic has shown no sign of I-mode. |
| Aug 27 2010 04:55:10:593PM | 1100827029 | Amanda Hubbard | 1.0 MA, 5.55 T. steady RF 0.3 MW.
Finally an extended I-mode. 0.9 to 1.3 s. There is a (very) weakly coherent mode about 230 GHz, which gets stronger at 1.15 s. Should have CXRS data from DNB and NINJA in this one. And there is an ELMy H-mode from 1.3-1.5 s for comparison. H98 is not great in either regime, shot 26 at higher power was much better. next (last) shot, return to conditions of shot 22 (800 kA, 700 kW) but leave Bt at 5.6 T since I think it is helping avoid the sawtooth-triggered H-modes. And try again to get CXRS data there. |
| Aug 27 2010 05:08:41:797PM | 1100827030 | Amanda Hubbard | 0.8 MA, 5.55 T. steady RF 0.7 MW.
Got a good extended I-mode (similar to shot 22) as we hoped. Clear WCM around 230 KHz. ELMy H-mode around 1.3 secs. So a nice partner to shot 29 at 1 MA. Got DNB and NINJA this time so hopefully we'll have good CXRS. No next shot, thanks everyone! |
| Physics Operator Comments | |||
| Aug 27 2010 08:53:19:050AM | Preparations for shot 1:
Fill gas extended to 50 ms. Loaded 1090902032, seg. 2, into Seg. 4 of today's shot. Called all magnetics predictors to re-calculate necessary coefficients. | ||
| Aug 27 2010 09:15:27:880AM | 1100827001 | Shot 1:
Large injection from high-field side, appears related to issues uncovered during yesterday's run. Preparation for next shot: Adjusted ZCUR to delay placement until after the inner gap has reached a larger value. This is based on suggestions from yesterday's team. | |
| Aug 27 2010 09:30:02:730AM | 1100827001 | Shot 2:
Full length shot, ZCUR adjustment seems to have allowed us to avoid the inner-wall injection issue. Preparation for next shot: Repeat shot, reviewing the time dependence of the bright spot that appears on the inner wall (see WIDE2). If this injection problem continues, then it might be worth attempting to make the plasma divert early. | |
| Aug 27 2010 09:43:03:707AM | 1100827001 | Shot 3:
Early disruption due to inner-wall hot spot. This suggests that yesterday's fix will not suffice today. Preparation for next shot: Increase GAS3 to a value of 40 through time 70 ms. The intention is to increase the density slightly and power through the inner wall pollution. | |
| Aug 27 2010 09:59:11:000AM | 1100827004 | Ian Hutchinson | Plasma to rampdown. No injection. H-mode gets quite hot.
Seems the early gas puff avoided the injection. Lower nl04 from 6 to 5.5e19. RF adjustments too. |
| Aug 27 2010 10:12:56:187AM | 1100827005 | David Pace | Shot 5:
Reduced NL04 to 5.5e19 per SL request. Shot ran full with reduced glow from inner-wall spot. Looks like an ELMy H-mode. Preparation for next shot: Move lower strike point in by 5 mm: RXL to -0.065 cm |
| Aug 27 2010 10:30:26:600AM | 1100827006 | David Pace | Shot 6:
Shot ran well, x-point successfully moved inward slightly. Preparation for next shot: Repeat 6, but add the argon puff (standard 50 ms pulse). |
| Aug 27 2010 10:48:03:560AM | 1100827007 | David Pace | Shot 7:
Repeat 6, but add the argon puff (standard 50 ms pulse). Shot ran, but start-up could be better. Plasma bounces near 14 ms, but recovers fully. Small increase in radiation corresponding to argon puff. Preparation for next shot: SL requests review of whether the equilibrium is not settling early enough. Review shows equilibrium is programmed to settle before 500 ms, with the ICRF beginning near 800 ms. |
| Aug 27 2010 11:04:12:587AM | 1100827008 | David Pace | Shot 8:
Repeat previous shot. Large injection at 1.5 s ends shot through disruption. Preparation for next shot: Repeat shot, SL coordinating changes in ICRF programming. |
| Aug 27 2010 11:23:11:900AM | 1100827009 | David Pace | Shot 9:
Possible that inner-wall injection source has returned; disruption at 250 ms. Preparation for next shot: Increase gas - GAS3, amplitude to 50, time extended to 100 ms. Slight change in RCUR, increasing the rate at which it moves out in order to reduce heat load on inner wall. RCUR goes to 0.652 at 168 ms. |
| Aug 27 2010 11:37:44:693AM | 1100827010 | David Pace | Shot 10:
Ran longer than previous shot, no early injections. Odd traces on multiple power supplies, Engineering team checking fuses on EF1_L and possibly others. Preparation for next shot: PO settings unchanged, Engineers report ready for shot attempt. |
| Aug 27 2010 12:04:28:160PM | 1100827011 | David Pace | Shot 11:
Shot ran well. After shot, received warning message concerning OH2U resistance reaching 2.7 micro-Ohms. Likely due to crowbar firing on previous shot. Expected that this will resolve itself since shot 11 ran full. Preparation for next shot: SL requests return to shape from shot 5. Due to multiple gas changes since then, we will return RXL to the value from shot 5 (-0.060), but leave everything else the same as in shot 10. |
| Aug 27 2010 12:17:09:280PM | 1100827012 | David Pace | Shot 12:
Shot ran well. Achieved RXL is slightly further in compared to shot 11. Preparation for next shot: SL requests additional step outward in RXL. Set RXL to -0.055. |
| Aug 27 2010 12:31:06:190PM | 1100827013 | David Pace | Shot 13:
Good shot, strike point moved out as desired. Preparation for next shot: Return strike point to furthest in position (see shot 11), and then move slightly further in. May go limited, so small step will be taken. Setting RXL = -0.07, which is a 5 mm inward step compared to shot 11. |
| Aug 27 2010 12:45:56:447PM | 1100827014 | David Pace | Shot 14:
Positioned strike point further in, setting RXL = -0.07. Early disruption. Major injection from inner wall near 200 ms, with multiple smaller injections prior. Preparation for next shot: Try again. |
| Aug 27 2010 01:04:32:850PM | 1100827015 | David Pace | Shot 15:
Shot ran full. Preparation for next shot: Move strike point out to furthest position. Setting RXL = -0.045. |
| Aug 27 2010 01:18:55:293PM | 1100827016 | David Pace | Shot 16:
Shot ran full. Preparation for next shot: Repeat shot 11, SL wants to review unique behavior from ohmic phase during that shot. |
| Aug 27 2010 01:31:00:723PM | 1100827017 | David Pace | Shot 17:
Shot ran well. Preparation for next shot: SL requests sweeping strike point outward beginning at 1.2 s |
| Aug 27 2010 01:48:09:213PM | 1100827018 | David Pace | Shot 18:
Strike point will sweep outward by 3 cm beginning at 1.2 s and ending at 1.4 s. Shot ran well. Preparation for next shot: load segment 4 from shot 12 load |
| Aug 27 2010 02:03:16:370PM | 1100827019 | David Pace | Shot 19:
Shot ran well. Preparation for next shot: Reduce NL04 to 4.5e19, otherwise repeat 19. |
| Aug 27 2010 02:14:30:523PM | 1100827020 | David Pace | Shot 20:
Shot ran well, achieved NL04 reduction to under 6e19. Preparation for next shot: Maintain programmed settings, SL will direct increased ICRF for physics scan. |
| Aug 27 2010 02:31:42:473PM | 1100827021 | David Pace | Shot 21:
Shot ran well, slow density rise from H-mode. Preparation for next shot: SL requests plasma program remain fixed; SL will coordinate ICRF power increase. |
| Aug 27 2010 02:48:46:247PM | 1100827022 | David Pace | Shot 22:
Shot ran well. Preparation for next shot: SL requests same plasma programming. SL will increase ICRF power and incorporate a NINJA puff. |
| Aug 27 2010 03:06:16:053PM | 1100827023 | David Pace | Shot 23:
Shot ran well. Preparation for next shot: SL requests same plasma programming. SL will coordinate a minor reduction in ICRF power. |
| Aug 27 2010 03:26:25:463PM | 1100827024 | David Pace | Shot 24:
Shot ran well. Preparation for next shot: Beginning plasma parameter scan by increasing I_p to 0.9 MA and increasing NL04 to 5e19. |
| Aug 27 2010 03:42:02:290PM | 1100827025 | David Pace | Shot 25:
Shot ran well. EF2 power supplies did not hit limits, suggests we try for 1.0 MA. Preparation for next shot: Increase plasma current to 1.0 MA. Increase B to 5.6 T (increasing TF current from 150 kA to 155 kA). |
| Aug 27 2010 03:59:56:827PM | 1100827026 | David Pace | Shot 26:
Shot ran well, EF2U came within about 10 A of limit; no negative impact on plasma performance. Preparation for next shot: SL requests plasma programming remains the same from the previous shot. |
| Aug 27 2010 04:10:27:900PM | 1100827027 | David Pace | Shot 27:
Shot ran well. Preparation for next shot: SL requests same plasma programming; SL will coordinate reduced ICRF power to avoid immediate H-mode transition. |
| Aug 27 2010 04:31:18:893PM | 1100827028 | David Pace | Shot 28:
Shot ran well. Preparation for next shot: SL requests same plasma programming; will coordinate ICRF power reduction. |
| Aug 27 2010 04:46:54:390PM | 1100827029 | David Pace | Shot 29:
Shot ran well Preparation for next shot: Reproduce shot 22 with the higher field of shot 29. |
| Aug 27 2010 04:59:45:680PM | 1100827030 | David Pace | Shot 30:
Shot ran well. Last Shot of the Day |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:59:48:837AM | Test | Ok | inner wall injections |
| 2 | 09:16:13:570AM | Plasma | Ok | |
| 3 | 09:29:24:740AM | Plasma | Ok | |
| 4 | 09:43:40:513AM | Plasma | Ok | |
| 5 | 09:59:04:660AM | Plasma | Ok | |
| 6 | 10:22:08:853AM | Plasma | Ok | |
| 7 | 10:36:55:100AM | Plasma | Ok | |
| 8 | 10:53:39:200AM | Plasma | Ok | |
| 9 | 11:09:45:013AM | Plasma | Ok | |
| 10 | 11:23:13:427AM | Plasma | Bad | PF breaker opened EF! self powered |
| 11 | 11:49:36:943AM | Plasma | Ok | |
| 12 | 12:05:53:247PM | Plasma | Ok | |
| 13 | 12:20:07:697PM | Plasma | Ok | |
| 14 | 12:35:47:730PM | Plasma | Ok | |
| 15 | 12:48:53:350PM | Plasma | Ok | |
| 16 | 01:04:39:370PM | Plasma | Ok | |
| 17 | 01:19:22:207PM | Plasma | Ok | |
| 18 | 01:35:05:447PM | Plasma | Ok | |
| 19 | 01:50:57:063PM | Plasma | Ok | |
| 20 | 02:06:50:503PM | Plasma | Ok | |
| 21 | 02:22:47:430PM | Plasma | Ok | |
| 22 | 02:39:03:367PM | Plasma | Ok | |
| 23 | 02:55:39:533PM | Plasma | Ok | |
| 24 | 03:12:05:677PM | Plasma | Ok | |
| 25 | 03:31:32:723PM | Plasma | Ok | |
| 26 | 03:47:43:903PM | Plasma | Ok | |
| 27 | 04:03:55:977PM | Plasma | Ok | |
| 28 | 04:20:02:937PM | Plasma | Ok | |
| 29 | 04:40:47:973PM | Plasma | Ok | |
| 30 | 04:56:52:520PM | Plasma | Ok | |
| System Availability | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Aug 27 2010 08:59:32:333AM | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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