| Miniproposals | ||||||||||
|
| Operators | |
| Session leader(s): | Amanda Hubbard |
| Physics operator(s): | Robert Granetz |
| Engineering operator(s): | Sam Pierson,Bill Parkin,Ed Fitzgerald |
| Engineering Operator Run Comment |
| MP 613, Part B: LHCD effectiveness in high Te H-modes. |
| Session Leader Plans |
| Entered: Jan 5 2011 02:07:29:787PM |
| Author: Amanda Hubbard |
| Run plan for 1110106. MP 613, Part B: LHCD effectiveness in high Te H-modes.
Session Leader: Amanda Hubbard Physics Operator: Bob Granetz The first order aim of the run is to measure LHCD and non-thermals vs density in RF-heated EDA H-modes, to compare with the trend in L-modes. And, to get sufficiently good edge and SOL data that we can later run models and interpret the differences. Our basic premise is that we think the high ne limit is an SOL effect, we know SOL profiles are different in L and H-modes, therefore the density limit is also likely to be different; higher or lower we don't know. Ideally we would find at least one H-mode condition where we DO see evidence of non-thermal and current drive. Critical diagnostics include HXR camera, and LH reflectometer. MSE and polarimeter are highly desirable. The cryopump is essential to control density. Argon (for HIREX) and Neon should be available, but do not use on first shots. Step 1: Scans at 600 kA 1a. Optimize low density H-mode target. 600 kA, ohmic nel 6 x1019 m-2, 5.4 T, cryopump on. 3.0 MW ICRF (from J and E-port). Start with SSep -5 mm, try sweeping up to slightly USN after H-mode is formed to minimize density. An excellent starting shot is 1101202020. 1b. Add LHCD, about 200 ms into steady H-mode phase to allow good baseline on x-rays, MSE. Start with N//=2.5, high enough to be comfortably accessible 400 kW LHCD on first shot, bring up to about 800 kW over 2-3 shots (or max achievable without excessive trips or impurity injections). 1c. Repeat with LSN discharge, which will likely give slightly higher density. Good shot is 1101202030. 1d. If as is likely the LH is affecting the pedestal and complicating analysis, repeat USN case with a puff of Neon. Expect that the extra radiation will reduce the pumpout (and give higher but steadier density). Will we still see increasing HXR, decreasing Vloop during LHCD? 1e. In the unlikely event we are still seeing some non-thermals, raise target density and repeat. Step 2 - repeat above steps (at least the useful ones) at 450 kA. Expect reduced density, and also more evident signs of current drive (eg Vloop) if there is any. Reduce N// if possible, maintaining accessibility. Step 3: For one or both currents, repeat with Double Null (Greg's L-mode experiments indicate higher non-thermals here). Step 4: If above results warrant (ie we saw some signs of non-thermals or current drive), repeat some steps at 800 kA. This is where we'd really like to run ITER hybrid scenarios, but density will be even higher. |
| Physics Operators Plans |
| Entered: Jan 5 2011 04:47:24:210PM |
| Author: Robert Granetz |
Engineering setup for Thursday 2011/01/06
MP613 - LHCD Effectiveness in high Te and confinement plasmas
Session leaders: A. Hubbard
Physics operator: R. Granetz
Overnight: standard ECDC and 60 C bake.
Run will start at 09:00 and end at 17:00.
Power systems as on: 1101202020 (0.62 MA, 5.4 T, 0.6e20 m-2 target, USN,
cryopump)
A-coil configuration: +Dtop -Dbot -Jtop +Jbot; Hybrid enabled (standard
configuration)
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)
leave NINJA as is
Enable the following gate valves and shutters, assuming no vacuum problems:
ECE, VUV, Z-bolo, HIREX-Sr, B-spectrometer GV
Torvac setup: keep gate valves open during pulse
Specific diagnostics: DNB, MSE, HXR array, LH probes, LH reflectometer,
edge TS
Desired diagnostics: polarimetry, scanning probes
------------------------------------------------------------------------------
Boronization: no
Impurity injector: no
ICRF: yes, 3 MW from E and J
LH: yes
DNB: yes
Cryopump: yes
------------------------------------------------------------------------------
Run plan: See the session leader's detailed run plan in the logbook. We
will start with 1101202020, which was swept from LSN to USN
during the shot. After optimizing the H-mode target, LHCD will
be added in to the mix.
|
| Session Leader Summaries |
| Entered: Jan 7 2011 01:22:46:113PM |
| Author: Amanda Hubbard |
| Run plan for 1110106. MP 613, Part B: LHCD effectiveness in high Te H-modes.
Session Leader: Amanda Hubbard Physics Operator: Bob Granetz The first order aim of the run was to measure LHCD and non-thermals vs density in RF-heated EDA H-modes, to compare with the trend in L-modes. And, to get sufficiently good edge and SOL data that we can later run models and interpret the differences. The run was quite successful and certainly very interesting. We essentially accomplished the 600 kA parts of the run plan, with good discharges in LSN and USN, and a few in DN. Set up the 450 kA target, but the gods were not with us in getting LH into it. We began the run with discharges shifted from LSN to USN, but had difficulties with RF conditioning (RF had not been used the day before). (Shots 1-3). So, we did the LSN H-modes first. ICRF worked fine at 600 kA. We found that unplanned L-modes (and hence lower density) led to k-limiter heating, likely due to fast ions. (eg shot 4).Adjusting the density feedback prevented going to such a low density. Shots 6-12 were in this configuration, with LH power steadily increased. Several shots had H-L-H transitions, which will provide density scans in L and H-mode but were confusing to see the LHCD effects. The best shot was 12, with 530 kW LHCD from 0.95 to 1.35 s. This gave clear density pumpout and temperature increase, with nebar 1.8 to 1.7e20 m-3, and Te rising (2.6-3.1 keV). Good confinement, with H98=0.85, including LH power. 70 kJ. There did however seem to be much sign of non-thermals, beyond the thermal baseline, on either ECE or HXR (possibly some effect on HXR). The pedestal eroded due to radiation late in the H-mode, making the turnoff comparison less clear. Brian got scanning probe data to compare with reflectometry, will be useful for QCL3D analysis. Shots 13-16 were in the USN configuration, and proved very interesting. We started by using the standard switch from LSN to USN, and turning on LHCD at 1 sec. As expected, this gave slighly lower H-mode density. But, we noted that the best H-modes occurred when there was a back-transtion, and a second L-H DURING the LHCD pulse. In these cases, both density and Prad were lower; apparently the 'pumpout effect' prevents accumulation. (eg shots 14, 16, 20). Nebar was down to 1.55e20 m-3, and prompt non-thermal signatures started to be seen on ECE, at ~ 500 eV level. Shots 16 and 20 are good examples; with LHCD, WMHD is 82 vs 60 kJ (beta_p 0.8). Te0 4 vs 2.7 keV. The strong rise in neutrons and Te complicates HXR and Vloop interpretation. Looks like about 4000 extra counts (out of 18k) on HXR Ch 16 during LHCD. From shot 21 on we thus decided to skip the lower performance ICRF-only H-mode, and turned both on together at 1 sec. ICRF and LH power were progressively raised Shot 22 (2 MW ICRF) had 80 kJ (beta_p0.8, H98 >1) and showed a definite drop in both HXR and non-thermal ECE when LH turned off at 1.4 s; good one for LHCD analysis since conditions were quite steady. Brian got probe data on shots 18-20 at least. Shots 24-26 increased power and performance, with the help of the magic Neon bullet. 25 and 26, with 3 MW ICRF, were particularly good! (and no indication we had maximized, could have increase RF). Shot 25 had 3 MW ICRF, 0.8 LHCD (tripping early). 108 kJ, H98 about 1.2 (including 90% LH absorption, so conservative) beta_pol=1. Te0 4.7 keV. nebar was 1.8e20 (a little higher with the Neon) Perhaps as a result, the non-thermals seem smaller (about 350 eV on ECE, and hard to pick out on HXR given the high neutron-induced background (27k on Ch 16). Shot 26 had less neon, slightly lower performance but much cleaner LH, so easier for LHCD analysis. Shots 27 and 28 were double null, 650 kA. Good H-modes, with 2 MW ICRF and no neon. But vertical disruptions. First order result was fairly similar non-thermals to USN shots, though the early RF trips and disruption will make background comparison of HXR difficult. Last few shots were spend at 450 kA, USN. Shot 29, with 2 MW ICRF, remained in L-mode. nebar 1.2e20, some non-thermals. 30 was a good H-mode target, with 3 MW ICRF, but LH didn't run. The last attempt resulted in an early shutdown. Given the success and high performance with 650 kA, it would be very useful to return to shot 30 another day. nebar was only 1.6e20 without LH, so we could expect even lower, and likely better current drive and higher beta_pol. All in all we learned a lot and have much to analyse. Not least of which is that we can do good LHCD and ICRF heating, together, at low current, as long as nebar is not too low; the fast ion problem appears not so bad in H-modes. And LHCD is a very useful control tool for H-mode particle transport, helping keep density and impurities low. CD efficiency in H-mode requires further analysis; initial assessment says it is non-negligible but likely not large either. Probably more than would have been obtained in L-mode at comparable average densities (1.5-1.9e20 m-3). Either way, we have obtained the SOL profile and non-thermal data to model and see if we can understand it. |
| Physics Operator Summaries |
| Entered: Jan 6 2011 07:16:17:703PM |
| Author: Robert Granetz |
Run summary for Thursday 2011/01/06
MP613 - LHCD Effectiveness in high Te and confinement plasmas
Session leader: A. Hubbard
Physics operator: R. Granetz
We successfully ran LH into ICRF-generated H-modes in USN with good
results. (See the SL summary.) The tokamak ran extremely well today, and both
the ICRF and LH also ran well into the USN plasmas. The DNB also ran
flawlessly at full performance. Most of the day we ran with a ZCUR scan to
go from LSN to USN at about t=0.8 s. We also tried a couple of shots at DN
(27,28), but they were vertically unstable.
Scorecard: 31 plasmas (last one was shut down early due to runaways)
0 duds
0 fizzles
0 power supply tests
0 no-power MDS shot cycle
--------------
Total: 31 shot cycles
|
| Session Leader Comments | |||
| Jan 6 2011 09:28:09:017AM | 1110106001 | Amanda Hubbard | Good plasma - 5.4 T, 620 kA, LSN to USN. But ICRF is low and ratty, Steve blames in on having an ohmic run yesterday (apparently he does not want any days off in future).
Retry, with ICRF ramped up more slowly. |
| Jan 6 2011 09:24:09:520AM | 1110106002 | Amanda Hubbard | Rather similar - went USN at 0.8 s as programmed. RF better but not great. And we got a disruption before 1.2 secs.
Did get a quite low density H-mode around 0.9 secs (nel 0.9e20 m-2, nebar 1.7e20 m-3). But nothing is steady. |
| Jan 6 2011 09:35:10:960AM | 1110106003 | Amanda Hubbard | This shot lasted longer (to 1.5 s) but RF and H-modes are still not steady at all.
Switch to all LSN, in the hopes the switch to USN is contributing to the issues. We may try USN later, once ICRF is better conditioned. |
| Jan 6 2011 09:57:51:777AM | 1110106004 | Amanda Hubbard | Full shot, LSN, and much better ICRF. But we got a back-transition to L-mode at 1 sec, and perhaps due to density feedback problems, never got H-mode. Apparently we heated the K-limiter.
Next: Back off on ICRF (to 2 MW). Fudge the density demand. And start adding a little LHCD (1.2-1.4 s). |
| Jan 6 2011 10:10:26:337AM | 1110106005 | Amanda Hubbard | Better. Got a fairly steady first H-mode, though Prad is rising more than I'd like. Brief LHCD at 1.2 s, which is after the back-transition. Did get a small response on GPC2 T10 which is encouraging.
Next: Move LH earlier in the hope of catching a steady period. |
| Jan 6 2011 10:23:27:940AM | 1110106006 | Amanda Hubbard | LHCD on at 0.95 s, into a fairly steady H-mode. Nebar 1.85e20. LH is tripping. No sign of non-thermals, though there is a slight increase in Tped at LH pulses.
Prad is increasing, probably independent of LH, and Tped eventually erodes, giving back-transition. Leave the plasma alone, try to get LH to stay on. |
| Jan 6 2011 10:38:57:187AM | 1110106007 | Amanda Hubbard | First useful shot for the MP. LHCD stays on at 0.95-1.15 s, 0.3 MW, into a fairly steady H-mode; nebar 1.83, drops to 1.72 e20 m-3. Clearly getting the LH pumpout effect, and Te8 rises 0.5 to 0.65 keV. But, not an evident non-thermal effect on the ECE. LH power is low; next shot, raise LH power, and extend its pulse length; we may catch the L-mode phase which would be an interesting comparison.
|
| Jan 6 2011 10:51:20:103AM | 1110106007 | Amanda Hubbard | First useful shot for the MP. LHCD stays on at 0.95-1.15 s, 0.3 MW, into a fairly steady H-mode; nebar 1.83, drops to 1.72 e20 m-3. Clearly getting the LH pumpout effect, and Te8 rises 0.5 to 0.65 keV. But, not an evident non-thermal effect on the ECE. LH power is low; next shot, raise LH power, and extend its pulse length; we may catch the L-mode phase which would be an interesting comparison. Not clear why we didn't get a second H-mode; it may be due to the low target density, which Bob will now raise for the whole flat top.
N// is 2.55, which according to Greg's widget is marginally accessible at the start of the LH, and comfortably so at the minimum H-mode density. Note ne starts rising (along with Prad) at 1.1 s. |
| Jan 6 2011 11:08:50:790AM | 1110106008 | Amanda Hubbard | LH not much higher, and tripping. Unfortunately the H-mode ended before LH this time. On the positive side, we did clearly get non-thermal ECE signatures at the L-mode density (nebar 1.0 to 0.9 e20 m-3). GPC2_T10 up to 1.7 keV,
Try again. |
| Jan 6 2011 11:23:18:170AM | 1110106009 | Amanda Hubbard | Much better - 0.35 MW LHCD into steady H-mode. But no visible effect!
Try to increase power... For some reason nebar was higher - no LH pumpout effect noted. So accessibility is marginal. |
| Jan 7 2011 11:27:18:547AM | 1110106010 | Amanda Hubbard | Got injections and an early H-L, then second late H-mode during LH.
ECE sees non-thermals suring L-mode, decreasing at injection. HXR Ch 16 mainly seems to follow the neutrons, peaks just AFTER LHCD. |
| Jan 6 2011 11:45:47:623AM | 1110106011 | Amanda Hubbard | Not bad until a big injection at 1 sec. Then H-L-H. LHCD to 0.6 kW.
Get LH non-thermals only in L-mode, and early in the second H-mode (which will be useful I guess as an H-mode density scan). Try again. Brian will try to get probe data in SOL. |
| Jan 6 2011 12:19:21:443PM | 1110106012 | Amanda Hubbard | Nice one! LSN, nice long steady H-mode. LHCD on 0.5 MW, 0.95-1.35 s.
Brian got probe scans. Checking HXR data before moving on. At first glance it looks like we did get a clear Tped increase, but no evident non-thermal ECE. nebar 1.8 to 1.7e20 m-3, about as low as we get at this Ip. We did get good HXR data. There is emission; it is low but non-negligible; higher than in L-modes at this density. But the background is at least 50% of the signal, and probably also increasing during LHCD, so careful correction will be needed. We will next try the USN configuration (as on shots 3,4) which should reduce the pedestal density. |
| Jan 6 2011 12:30:55:230PM | 1110106013 | Amanda Hubbard | Switch LSN to USN at 0.8 s. Got an RF trips and/or H-L transition just before the LHCD, and a big Fe injection at 1.05 s. Try again, with LH a little later (1.0 s) to give equilibrium and density more time to settle down. |
| Jan 6 2011 12:52:52:320PM | 1110106014 | Amanda Hubbard | Interesting shot. Once again there was a trip/H-L transtion before the LH. But then a second, lower density H-mode with LHCD. nebar only 1.5e20. And there are now distinct prompt changes in GPC2_10; only few 100 eV, but there.
The H-mode with LHCD was a lot hotter; 4 keV vs 3 keV. Try again. |
| Jan 6 2011 01:01:37:893PM | 1110106015 | Amanda Hubbard | Much longer H-mode, density gradually decreasing to 1.7e20 m-3.
But LH did not couple well. Will tweak gaps etc to improve this. |
| Jan 6 2011 01:20:58:293PM | 1110106016 | Amanda Hubbard | Much better. 2 H-modes; first trips early in LHCD, and the second, which is after LHCD, is MUCH better - lower density (nebar 1.56e20) lower Prad, and higher Te 4 keV vs 2.7. This will complicate interpretation, but maximize chances of seeing effects. Vloop down to 0.2 V! The turnoff phase will be helpful in separating Te and current drive effects. There are a few 100 eV of prompt non-thermal ECE.
Repeat, Brian will use probes. And Jim the polarimeter. |
| Jan 6 2011 01:26:07:167PM | 1110106017 | Amanda Hubbard | Single, fairly steady, H-mode. But LHCD had HV trip, no power at all.
nebar 1.93 in LSN, 1.7 in USN; a good reference for what happens sans LHCD. Brian got probe data. Vloop 0.67 V. Prad ! 1 MW, sitll suing 2 MW ICRF (time to try increasing??) Te8 400 eV, Te0 2.6 keV. |
| Jan 6 2011 01:43:41:600PM | 1110106018 | Amanda Hubbard | Repeat- only a little brief LHCD. ne and Prad rise (nebar 1.7-1.96e20) duing LH at 1.15-1.2 s.
About 100 eV prompt non-thermal emision. Try again, hope for better. |
| Jan 6 2011 02:00:41:700PM | 1110106019 | Amanda Hubbard | Hope not fulfilled; even more trips/less LH. Greg is stumped.
Will reduce N// to 2.3 (from 2.5). This will only be accessible if the density pumps out. |
| Jan 6 2011 02:25:26:523PM | 1110106020 | Amanda Hubbard | This shot had an H-L before the LHCD. And probably as a result, the LH was much happier. Second H-mode had lower ne and Prad; would have been even lower except for an injection (probe?) at 1.2 s.
Get non-thermal ECE (up to 1.7 keV) in the L-mode, and H-mode evolution. Clear drop at 1.4 s when LH off; 400 eV. Not huge, but there. Thermal component drops much more slowly. nebar 1.55e20, N//=2.3 next: Try deliberately starting H-mode with LHCD in USN; turn on ICRF and LH together at 1 sec. No probe. |
| Jan 6 2011 02:59:33:907PM | 1110106021 | Amanda Hubbard | It worked! Nice L-H at 1.1 s, density stays low, then pumps further, to 1.58e20. Clean LH, 600 kW, N//=2.34.
Turn off LHCD at 1.4 s, 400 eV drop in GPC2 Ch 10. Vloop rising, we'll need to look at response times to separate Te and CD effects. Repeat, more LH power. |
| Jan 6 2011 02:58:08:080PM | 1110106022 | Amanda Hubbard | Repeat, vs similar. Nice L-H at 1.1 s, Clean LH, 630 kW, N//=2.34.
Prad stays below 600 kW, perhaps the biggest benefit of using lH from the beginning of the H-mode. Turn off LHCD at 1.4 s, 450 eV drop in GPC2 Ch 10. Greg thinks he can provide even more power, so go for it. |
| Jan 6 2011 03:11:56:690PM | 1110106023 | Amanda Hubbard | Good LH at 700 kW. H-mode not as good; early phase very hot, and Vloop down to 0.2 V. nebar 1.63. Likely ELM at 1.2 s. Then get small injections, around 1.25 s, which erode Te, and Prad rises; not as much non-thermals by the end so the turnoff comparison will not be as clear. But Vloop =0.7 V with ICRF only.
Next: Try more ICRF power (k-limiter is nice and cool). |
| Jan 6 2011 03:29:23:380PM | 1110106024 | Amanda Hubbard | Got 3 MW ICRF, only a few trips. Still 700 kW LH (with correlated trips).
But also several injections, and a back transition, so much less steady. Time to try the Neon! Did get Vloop below 0.2 V for a while in each H-mode. And some signficant (~ 600 eV) non-thermal emission. But the time traces will be hard to interpret. Te0 up to 5 keV |
| Jan 6 2011 03:48:35:783PM | 1110106025 | Amanda Hubbard | Very nice - Neon did its job, eliminated the RF trips and injections. (Thanks Matt for the recipe) Prad a little higher overall (to 1.2 MW) but much steadier. Likely as a result, nebar is a little higher, 1.8e20; N// 2.3 is marginally accessible. 800 kW, clean until 1.28 s, then
Nice hot plasma, Te0 4.8 keV, 107 kJ. Decreasing after LH trips. Non-thermal ECE around 350 eV, lower than before. Vloop 0.2 to 0.3 V in LH, 0.4 V after. |
| Jan 6 2011 04:04:55:003PM | 1110106026 | Amanda Hubbard | Another very good one. Using slightly less Neon did not help, marginally lower T and W. But still very high performance. And long, steady LH pulse making effects at turnoff easier to see. Vloop 0.2-0.35 V with LH, 0.47 with ICRF only (after 1.4 s). Prompt non-thermal drop about 300 eV. nebar 1.77.
This is as good as we are likely to get at this condition, we have plenty to analyse. Next: Back off on ICRF power, try double null to see if non-thermals are (as in L-mode plasmas) higher. |
| Jan 6 2011 04:19:31:290PM | 1110106027 | Amanda Hubbard | Double null or close to it. Looks good but not notable better than LSN; Vloop about 0.5 V, non-thermals about 400 eV.
RF 2 MW, LH 730 kW. nebar 1.85 to 1.7 e20 m-3. Te0 a mere 3.2 keV. Vertical instability gives a disruption. |
| Jan 6 2011 04:33:01:460PM | 1110106028 | Amanda Hubbard | Double null again. A period of trippage on both LH and ICRF, and another vertical disruption. First order result is that non-thermal ECE is pretty similar to upper null, as is Vloop; we will analyse this more carefully later.
Given the late time, going to try a few shots at USN, 450 kA. Keep an eye on k-lim! If I melt it, this was Martin's idea. |
| Jan 6 2011 04:44:04:983PM | 1110106029 | Amanda Hubbard | Upper null, 450 kA. For some reason this shot stayed in L-mode, despite 2 MW of nice clean ICRF. nebar 1.3-1.2e20 m-3. LH 0.8 MW, but many trips. non-thermals about 500 eV; this will at least be an RF-heated L-mode data point. But no trophy... |
| Jan 6 2011 05:08:58:390PM | 1110106030 | Amanda Hubbard | Got a really nice H-mode, 450 kA, 66 kW. But no LHCD at all.
Even without it, density rise is v low, 1.7-1.6 e20 m-3. And Prad stays low, 0.6 MW vs 3 MW ICRF. Vloop 0.13 min, 0.33 steady. Call this the reference shot, and cross fingers for good LHCD on the next (last) shot. |
| Jan 6 2011 05:12:06:080PM | 1110106031 | Amanda Hubbard |
Not to contradict my phys-op, but it was an early non-thermal shutdown, pre ICRF and LHCD. So seeing LHCD at this current will have to await another day. But, we have a lot of good discharges at 600 kA to analyse. And a good starting shot for the next go at this. Thanks everyone! |
| Physics Operator Comments | |||
| Jan 6 2011 09:09:08:077AM | 1110106001 | Robert Granetz |
Shot 01 -- Plasma, disrupted at t=1.26 s. Not an injection; might have been vertically unstable,
but it shouldn't have been. 0.6 MA, 5.4 T, 0.6e20 m-2, cryopump. LSN -> USN. ICRF was
faulting alot. Brief H-modes.
Next shot: no DPCS changes; tuning the ICRF
|
| Jan 6 2011 09:20:41:250AM | 1110106002 | Robert Granetz |
Shot 02 -- Plasma, disrupted at t=1.18 s. Not vertically unstable, but looks like a VDE. Might
be a very fast-acting injection. RF still needs more tuning.
Next shot: repeat, no DPCS changes
|
| Jan 6 2011 09:36:38:277AM | 1110106003 | Robert Granetz |
Shot 03 -- Plasma, disrupted at t=1.51 s at the end of flattop. Te is rolling over before the
disruption, just like the previous shot. Not vertically unstable (i.e. EFC is not
railing), but it looks like another VDE. RF still having problems.
Next shot: change to LSN (rather than LSN -> USN) by turning on seg 3 and turning off seg 2;
reduce argon pulse to 20 ms (from 50 ms)
|
| Jan 6 2011 09:56:01:620AM | 1110106004 | Robert Granetz |
Shot 04 -- Plasma, full length. 0.6 MA, 5.4 T, 0.6e20 m-2, cryopump, LSN. Good ICRF, 3 MW.
H-mode until t=1 s, then reverts to L-mode and doesn't come back. Density feedback
seems to slightly off in its calibration. K-limiter is getting hot.
Next shot: decrease ICRF power; turn on LH; increase nl_04 programming to 0.75e20 m-2
|
| Jan 6 2011 10:06:07:297AM | 1110106005 | Robert Granetz |
Shot 05 -- Plasma, full length. Prf=2.0 MW and clean. LH faulted alot. Longer H-mode,
followed by short H-modes. Startup was not very good. K-limiter didn't get hot
at the reduced Prf.
Next shot: add -10 A to IC_EF4; tune up LH
|
| Jan 6 2011 10:23:43:150AM | 1110106006 | Robert Granetz | Shot 06 -- Plasma, full length. Prf=2 MW, clean. LH is still faulting alot. Next shot: add another -5 A to IC_EF4 |
| Jan 6 2011 10:49:12:023AM | 1110106007 | Robert Granetz |
Shot 07 -- Plasma, full length. Prf=2 MW, clean. P_LH=285 kW, clean. Got LH into an EDA H-mode.
Next shot: turn on 20 ms argon pulse; extend density programming to t=1.6 s; At Steve Wolfe's
suggestion, I also turned off the integral gain on nl_04 so that the H-modes
don't build up a large offset on the feedback error
|
| Jan 6 2011 11:02:37:763AM | 1110106008 | Robert Granetz |
Shot 08 -- Plasma, full length. Prf=2 MW, clean. P_LH=0.3 MW, with some faulting. One
H-mode which didn't last long, and didn't come back.
Next shot: increase gain on nl_04 to 7 (from 2)
|
| Jan 6 2011 11:16:35:113AM | 1110106009 | Robert Granetz |
Shot 09 -- Plasma, disrupted during rampdown. Prf=2 MW, clean. P_LH=0.4 MW, clean. Good
long H-mode.
Next shot: no DPCS changes
|
| Jan 6 2011 11:29:57:980AM | 1110106010 | Robert Granetz |
Shot 10 -- Plasma, full length. Two H-modes. Prf=2 MW, clean. P_LH=0.4 MW, clean. nl_04 feedback
worked well during the intervening L-mode.
Next shot: no DPCS changes
|
| Jan 6 2011 11:48:46:183AM | 1110106011 | Robert Granetz |
Shot 11 -- Plasma, full length. Prf=2 MW, one short fault. P_LH=0.4-0.5 MW. Several
H-modes.
Next shot: no DPCS changes; Brian will run the ASP
|
| Jan 6 2011 12:02:27:590PM | 1110106012 | Robert Granetz |
Shot 12 -- Plasma, full length. Prf=2 MW, P_LH=0.52 MW. Good long steady H-mode. Nice
shot. ASP ran.
Next shot: switch to seg 2, which is LSN -> USN
|
| Jan 6 2011 12:25:12:597PM | 1110106013 | Robert Granetz |
Shot 13 -- Plasma, disrupted during rampdown. Prf=2 MW with some minor faulting; LH faulted alot.
LSN -> USN. One long H-mode.
Next shot: no DPCS changes; delay LH start to t=1.0 s
|
| Jan 6 2011 12:39:14:373PM | 1110106014 | Robert Granetz |
Shot 14 -- Plasma, disrupted in rampdown. LSN -> USN. Two H-modes. Prf=2 MW, P_LH ~ 0.5 MW with lots
of faulting.
Next shot: no DPCS changes
|
| Jan 6 2011 01:01:04:097PM | 1110106015 | Robert Granetz |
Shot 15 -- Plasma, nearly full length. LSN -> USN. 0.6 MA, 5.4 T, 0.65e20 m-2, cryopump.
Prf=2 MW, P_LH faulted badly. One long H-mode.
Next shot: tweak RCUR in seg 2 to keep outer gap more constant
|
| Jan 6 2011 01:09:24:977PM | 1110106016 | Robert Granetz |
Shot 16 -- Plasma, full length. Two H-modes. Prf=2 MW, P_LH=0.55 MW. Outer gap is much more
constant.
Next shot: no DPCS changes; turn on ASP
|
| Jan 6 2011 01:23:28:990PM | 1110106017 | Robert Granetz |
Shot 17 -- Plasma, full length. LSN -> USN. One long H-mode. Prf=2 MW. LH had an HV trip.
ASP ran.
Next shot: repeat for LH
|
| Jan 6 2011 01:39:38:857PM | 1110106018 | Robert Granetz |
Shot 18 -- Plasma, disrupted in rampdown. LSN -> USN. One long H-mode. Prf=2 MW, P_LH=0.3-0.4 MW with
lots of faulting.
Next shot: no DPCS changes
|
| Jan 6 2011 02:06:26:553PM | 1110106019 | Robert Granetz | Shot 19 -- Plasma, full length. LSN -> USN. Prf=2 MW, LH faulted badly. Next shot: no DPCS changes |
| Jan 6 2011 02:19:26:080PM | 1110106020 | Robert Granetz |
Shot 20 -- Plasma, full length. LSN -> USN. Prf=2 MW, P_LH=0.6 MW and clean. Two H-modes, and
again the 2nd one has higher Te and lower ne.
Next shot: no DPCS changes; delay ICRF turn-on until t=1.0 s to see if the LSN portion
of the discharge is unnecessary.
|
| Jan 6 2011 02:31:36:410PM | 1110106021 | Robert Granetz |
Shot 21 -- Plasma, full length. LSN -> USN, but both the ICRF and LH don't turn on until we
get into USN. Nevertheless, ICRF+LH result in a very good H-mode. Prf=2 MW, P_LH=0.6 MW.
Next shot: repeat; increase LH power
|
| Jan 6 2011 02:57:37:550PM | 1110106022 | Robert Granetz |
Shot 22 -- Plasma, disrupted in rampdown. LSN -> USN, but ICRF and LH are only in in USN.
Good H-mode in USN, similar to preceding shot. DNB timing optimized to have a pulse
after LH turnoff but before ICRF turnoff. Prf=2 MW, P_LH=0.66 MW.
Next shot: repeat; tweak DNB timing some more
|
| Jan 6 2011 03:10:23:347PM | 1110106023 | Robert Granetz |
Shot 23 -- Plasma, disrupted in rampdown. LSN -> USN. ICRF+LH in LSN, with good H-mode.
Prf=2 MW, P_LH=0.74 MW. DNB timing is optimized for MSE.
Next shot: no DPCS changes; increase Prf
|
| Jan 6 2011 03:25:59:173PM | 1110106024 | Robert Granetz |
Shot 24 -- Plasma, disrupted during rampdown. LSN -> USN. ICRF+LH in USN. Not as good
as preceding shots. Short H-modes. Prf=3 MW, P_LH=0.75 MW.
Next shot: turn on neon (2 psi in H-bottom) and program a 100 ms pulse starting at t=0.85 s.
|
| Jan 6 2011 03:43:55:963PM | 1110106025 | Robert Granetz |
Shot 25 -- Plasma, full length. LSN -> USN. ICRF+LH in USN. Good H-mode. Prf=3 MW, P_LH=0.78 MW.
Neon puffing may have helped the ICRF performance.
Next shot: decrease neon pulse amplitude to 60 V (was 70 volts)
|
| Jan 6 2011 03:58:36:880PM | 1110106026 | Robert Granetz | Shot 26 -- Plasma, full length. Slightly less neon, but very similar results as preceding shot. Next shot: program ZCUR to hold at double null from t=0.8 s onward; turn off neon puff |
| Jan 6 2011 04:12:43:927PM | 1110106027 | Robert Granetz |
Shot 27 -- Plasma, disrupted at t=1.45 s. I think it was vertically unstable. LSN -> DN (nearly).
Good H-mode.
Next shot: Tweak ZCUR down 0.5 mm
|
| Jan 6 2011 04:27:06:020PM | 1110106028 | Robert Granetz |
Shot 28 -- Plasma, disrupted at t=1.33 s. LSN -> DN, but vertically unstable.
Next shot: return to LSN -> USN ZCUR programming on shot 26; reduce Ip to 450 kA; turn off DNB for
one shot (at Steve Scott's request)
|
| Jan 6 2011 04:41:12:690PM | 1110106029 | Robert Granetz |
Shot 29 -- Plasma, full length. 0.47 MA, 5.4 T, 0.6e20 m-2, cryopump, LSN -> USN.
Prf=2 MW; P_LH=0.7 MW with faults. But plasma stayed in L-mode. DNB was off
for this shot only, at the request of the MSE guys.
Next shot: repeat; increase Prf; decrease P_LH; DNB back on
|
| Jan 6 2011 04:57:43:173PM | 1110106030 | Robert Granetz |
Shot 30 -- Plasma, full length. LSN -> USN. Got the H-mode, but LH had HV fault. Prf=2.9 MW.
DNB is back on.
Next shot: repeat for LH
|
| Jan 6 2011 07:10:50:110PM | 1110106031 | Robert Granetz |
Shot 31 -- Plasma, but it was shut down early because it was a runaway discharge
with copious hard xrays. Oh well, that's the only one today.
End of run
|
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:00:27:207AM | Plasma | Ok | |
| 2 | 09:13:10:780AM | Plasma | Ok | |
| 3 | 09:25:50:223AM | Plasma | Ok | |
| 4 | 09:41:03:893AM | Plasma | Ok | |
| 5 | 09:57:05:147AM | Plasma | Ok | |
| 6 | 10:11:49:683AM | Plasma | Ok | |
| 7 | 10:28:01:217AM | Plasma | Ok | |
| 8 | 10:53:41:460AM | Plasma | Ok | |
| 9 | 11:08:10:790AM | Plasma | Ok | |
| 10 | 11:23:09:303AM | Plasma | Ok | |
| 11 | 11:38:39:153AM | Plasma | Ok | |
| 12 | 11:54:03:963AM | Plasma | Ok | |
| 13 | 12:17:03:550PM | Plasma | Ok | |
| 14 | 12:32:20:780PM | Plasma | Ok | |
| 15 | 12:48:01:207PM | Plasma | Ok | |
| 16 | 01:03:23:827PM | Plasma | Ok | |
| 17 | 01:19:34:343PM | Plasma | Ok | |
| 18 | 01:34:53:787PM | Plasma | Ok | |
| 19 | 01:50:47:327PM | Plasma | Ok | |
| 20 | 02:07:26:957PM | Plasma | Ok | |
| 21 | 02:24:09:267PM | Plasma | Ok | |
| 22 | 02:43:02:933PM | Plasma | Ok | |
| 23 | 02:58:23:730PM | Plasma | Ok | |
| 24 | 03:14:47:530PM | Plasma | Ok | |
| 25 | 03:30:53:833PM | Plasma | Ok | |
| 26 | 03:46:57:073PM | Plasma | Ok | |
| 27 | 04:02:25:610PM | Plasma | Ok | |
| 28 | 04:17:20:940PM | Plasma | Ok | |
| 29 | 04:33:33:723PM | Plasma | Ok | |
| 30 | 04:52:21:777PM | Plasma | Ok | |
| 31 | 05:08:08:600PM | Plasma | Ok | |
| System Availability | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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