| Miniproposals | ||||||||||
|
| Operators | |
| Session leader(s): | Martin Greenwald |
| Physics operator(s): | Dmitri Mossessian |
| Engineering operator(s): | Bill Cochran,Gary Dekow |
| Engineering Operator Run Comment |
| In support of MP #233A Density Limits.Greenwald/Mossessian/Cochran/Dekow |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:24:477PM |
| Author: To Be Determined |
| mp 233a Density limits (H-mode task force) Session Leader - Greenwald Phys Op - Mossessian ============================ Plan: (run continues from 1000609) We want to look at fluctuations near the density limit (both H/L and disruptive). Data from the previous run showed a substantial increase in fluctuations and autocorrelation near the density limit. Today we will: 1.Fire the scanning probe at various times before the limit to map out the change in fluctuations and transport. 2. Measure the convected flux with new probe head. 3. Compare to limited plasma 4. If time is available - run at lower field The run follows the general approach of 980115 where we ran high density H-modes then ramped the current down to the density limit. The TF needs to be kept on during the initial part of the IP rampdown. The outer gap should be in the range 1-1.5 cm so that we can get good data from the Lyman alpha array. ======================================================= Results: We finished #1 and #2 and started on #3 of the run plan. We got lots of good data. Successful ASP and FSP scans were done in divertor plasmas covering 0.4 - 1.0 x limit. We should have the data to characterize the fluctuations across this range. As before, the fluctuation levels and autocorrelation times for fluctuations at the separatrix increase near the density limit. We also got good data from the PCI. It showed the growth of incoherent low frequency fluctuations (<100 kHz) as the limit was approached. There was also a clear shift toward lower frequencies. ================================ Shots suitable for further analysis include: 1000620001 Good shot, disrupts at limit 1000620004 disrupts at limit ASP scaning 3 times: .6, .8, 1.04 FSP scanning 2 times: .6, .8 sec 1000620005 ASP scaning 3 times: .6, .8, 1.03 FSP scanning 2 times: .6, .8, 1.03 sec interesting data from PCI too 1000620006 ASP scaning 3 times: .6, .8, 1.03 FSP scanning 2 times: .6, .8, 1.03 sec last probe plunge a bit late - into the marfe 1000620007 ASP scaning 3 times: .6, .8, 1.02 FSP scanning 3 times: .6, .8, 1.02 sec last plunge went in during marfe Good data from PCI 1000620008 ASP scanning 2 times: .7, .95, FSP scanning 2 times: .7, .95 sec Good PCI data 1000620009 Good PCI data again ASP scanning 2 times: .65, .9, FSP scanning 2 times: .65, .9 sec excellent data. 1000620010 ASP scanning 2 times: .6, .8, 1.02, FSP scanning 1 time: 1.02 sec excellent data. 1000620011 ASP scanning 2 times: .7, .95, FSP scanning 1 time: .95 sec ASP a bit hot on first scan 1000620012 ASP scanning 2 times: .65, .90, FSP scanning 1 time: .90 sec 1000620013 ASP scanning 2 times: .6, .85, FSP scanning 1 time: .85 sec 1000620014 First try to flattop Ip and get limit with dI/dt = 0 plasma didn't have time however 1000620015 Short flattop still disrupts at the limit 1000620016 keep plasma limited Stays marginally diverted ends in sharkfin 1000620020 limited plasma very high densities poloidally detached densities peaking 1000620021 Doesn't poloidally detach, but does disrupt at limit some density peaking ASP scanning 3 times: .6, .85, 1.1 FSP not scanning. 1000620023 Better, disrupts at 1 sec - reaches limit ASP scanning 3 times: .6, .8, 1.0 FSP scanning 3 times: .6, .8, 1.0 Also not deep enough. 1000620024 Good shot - for limited plasma ASP scanning 2 times: .6, .93 FSP scanning 2 times: .6, .93 Also not deep enough. |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:37:11:410PM |
| Author: To Be Determined |
| Physop summary for 1000620: _________________________ Run plan: in support of MP233A Density Limits SL M.Greenwald PO D.Mossessian Engineering setup Power system setup as on 1000606014 Gas setup - fill B-top with 6 psi of D2 Hybrid enabled fill B-side lower with 1 psi of Ar Hybrid DISABLED leave B-side upper as is Hybrid DISABLED fill C-side with 30 psi of D2 Hybrid enabled J-bottom with 30 psi of D2 Hybrid enabled The following gate valves should be enabled: ECE, VUV DNB disabled PCS load from 1000609017. _____________________________ Summary: Good run. No OH tests were done and we went straight to plasma shots. Although every shot ended in high density disruption (as it was supposed to), the machine ran very well. There was only 3 fizzles. One happened when PO decided that the prefill pressure was too low and added 2 msec to the prefill pulse. That resulted in very slow current rise. Two others occurred because of small Br/Bz drifts. Some lower x-point position tweaks and current waveform tweaks were executed to satisfy scanning probes and session leader (see details below). Starting from shot 15 we ran inner wall limited plasma. Scorecard: 24 shots 3 fizzles 21 plasma _______________________ Details: 1000620001 Plasma. DNB valve was disabled and G-side pressure is 0.048 instead of usual 0.065 For next shot - add 2msec to prepuff ----------------------------------------------------------------------------- 1000620002 Fizzle. Current rise too slow. Gas is where I wanted it to be (0.055 mtorr), but perhaps it wants it lower For next shot: return prefill back to 19 msec. Drop Bz (IC_EF4 -1290 -> 1300) ----------------------------------------------------------------------------- 1000620003 Plasma. Startup is just like 1000620001. For next shot: no changes ----------------------------------------------------------------------------- 1000620004 Plasma. For next shot: no changes ----------------------------------------------------------------------------- 1000620005 Plasma. For next shot: pulled Z-XL down 8 mm at 1.1 sec for F-probe ----------------------------------------------------------------------------- 1000620006 Plasma. Z_XL flattened as expected. For next shot: no changes ----------------------------------------------------------------------------- 1000620007 Plasma. For next shot: no changes ----------------------------------------------------------------------------- 1000620008 Plasma. For next shot: no changes ----------------------------------------------------------------------------- 1000620009 Plasma. For next shot: no changes ----------------------------------------------------------------------------- 1000620010 Plasma. For next shot: no changes ----------------------------------------------------------------------------- 1000620011 Plasma. For next shot: no changes ----------------------------------------------------------------------------- 1000620012 Plasma. For next shot: no changes ----------------------------------------------------------------------------- 1000620013 Plasma. For next shot: flatten current at .7MA between 1 and 1.3 sec. Extended Z_XL slope to 1.35 sec (hoping that in reality it'll stay constant) ----------------------------------------------------------------------------- 1000620014 Plasma. Disrupted 30 msec after Ip was supposed to go flat. It's not clear, whether Ip actually flatten. For next shot: rise current flattop to 735000A and extend it back to .99 sec to keep const rampdown rate before. ----------------------------------------------------------------------------- 1000620015 Plasma. Flattop OK. For next shot: get rid of Ip flattop. Try to make plasma inside limited CLEARIN -0.01 -> -.025, keeping the right gap const (RCUR down by 0.007) ----------------------------------------------------------------------------- 1000620016 Plasma. Not really limited yet For next shot: make CLEARIN more negative (-.035) ----------------------------------------------------------------------------- 1000620017 Fizzle. Bz too low. For next shot: add 15A to IC_EF4 ----------------------------------------------------------------------------- 1000620018 Fizzle. Bz now seems to be too high. Br has been too high on last 2 shots. For next shot: take 15A off IC_EF4. Lower Br 0.5mT ----------------------------------------------------------------------------- 1000620019 Plasma. Slow current rise. For next shot: No changes in segment 1. Lower target density to 1.7e20 CLEARIN more negative (-.05) and change RCUR accordingly ----------------------------------------------------------------------------- 1000620020 Plasma. Right gap is too large (3 cm). For next shot: disable J-bottom gas valve, increase RCUR 1 cm to make right gap smaller ----------------------------------------------------------------------------- 1000620021 wolfe sitting in for Dmitri- Shot 21 is ok, but right gap is too small early. next shot: Rcur fro .665 to .662 at 0.5sec, to increase right gap by 6mm early. ----------------------------------------------------------------------------- 1000620022 Plasma. Disrupted at .55 sec. One of the reasons may be that it gets to q95=3 at that point For next shot: lower max Ip to 0.9 MA ----------------------------------------------------------------------------- 1000620023 Plasma. Disrupted at 1 sec at density limit. For next shot: no changes ----------------------------------------------------------------------------- 1000620024 Last shot. Plasma. |
| Session Leader Comments | |||
| Jun 20 2000 09:03:55:170AM | Martin Greenwald | Plan: (run continues from 1000609) We want to look at fluctuations near the density limit (both H/L and disruptive). Data from the previous run showed a substantial increase in fluctuations and autocorrelation near the density limit. Today we will: 1.Fire the scanning probe at various times before the limit to map out the change in fluctuations and transport. 2. Measure the convected flux with new probe head. 3. Compare to limited plasma 4. If time is available - run at lower field The run follows the general approach of 980115 where we ran high density H-modes then ramped the current down to the density limit. The TF needs to be kept on during the initial part of the IP rampdown. The outer gap should be in the range 1-1.5 cm so that we can get good data from the Lyman alpha array. | |
| Jun 20 2000 09:14:07:903AM | 1000620001 | Martin Greenwald | Good shot, disrupts at limit |
| Jun 20 2000 09:31:15:687AM | 1000620002 | Martin Greenwald | fizzle |
| Jun 20 2000 09:50:10:483AM | 1000620003 | Martin Greenwald | RF on - miscommunication disrupts too early |
| Jun 20 2000 10:13:45:873AM | 1000620004 | Martin Greenwald | Better - oh only disrupts at limit reasonable probe data |
| Jun 20 2000 10:49:51:123AM | 1000620005 | Martin Greenwald | Another good shot fsp running too interesting data from PCI too |
| Jun 20 2000 11:06:50:547AM | 1000620006 | Martin Greenwald | Good shot last probe plunge a bit late - into the marfe |
| Jun 20 2000 11:34:39:183AM | 1000620007 | Martin Greenwald | Another good shot Good positions on both probes last plunge went in during marfe Good data from PCI |
| Jun 20 2000 12:01:43:750PM | 1000620008 | Martin Greenwald | Good shot Good PCI data |
| Jun 20 2000 12:03:27:513PM | 1000620009 | Martin Greenwald | Similar Good PCI data again |
| Jun 20 2000 12:29:55:200PM | 1000620010 | Martin Greenwald | Good shot again |
| Jun 20 2000 01:07:35:013PM | 1000620011 | Martin Greenwald | Good shot ASP a bit hot on first scan |
| Jun 20 2000 12:59:27:950PM | 1000620012 | Martin Greenwald | Good shot again |
| Jun 20 2000 01:49:58:107PM | 1000620014 | Martin Greenwald | First try to flattop Ip and get limit with dI/dt = 0 plasma didn't have time however |
| Jun 20 2000 02:09:06:513PM | 1000620015 | Martin Greenwald | Short flattop still disrupts at the limit |
| Jun 20 2000 02:27:43:670PM | 1000620016 | Martin Greenwald | Go back to ramp - keep plasma limited Stays marginally diverted ends in sharkfin |
| Jun 20 2000 02:42:20:640PM | 1000620017 | Martin Greenwald | fizzle |
| Jun 20 2000 04:02:32:623PM | 1000620020 | Martin Greenwald | limited plasma very high densities poloidally detached densities peaking |
| Jun 20 2000 04:04:03:700PM | 1000620021 | Martin Greenwald | Doesn't poloidally detach, but does disrupt at limit some density peaking |
| Jun 20 2000 04:21:06:903PM | 1000620022 | Martin Greenwald | disrupts early |
| Jun 20 2000 04:43:00:827PM | 1000620023 | Martin Greenwald | Better, disrupts at 1 sec - reaches limit |
| Jun 20 2000 05:03:34:903PM | 1000620024 | Martin Greenwald | Good shot - for limited plasma looks like good probe data |
| Physics Operator Comments | |||
| Jun 20 2000 08:29:55:547AM | Dmitri Mossessian | Run plan for 1000620 in support of MP233A Density Limits SL: Greenwald PO: Mossessian Engineering setup Run begins at 9:00 and ends at 17:00. Power system setup as on 1000606014 Gas setup - fill B-top with 6 psi of D2 Hybrid enabled fill B-side lower with 1 psi of Ar Hybrid DISABLED leave B-side upper as is Hybrid DISABLED fill C-side with 30 psi of D2 Hybrid enabled leave J-bottom as is Hybrid DISABLED The following gate valves should be enabled: ECE, VUV, DNB _____________________________________ 8:27. Loaded from 1000609017. Cold start OK | |
| Jun 20 2000 09:22:43:920AM | 1000620001 | Dmitri Mossessian | Plasma. DNB valve was disabled and G-side pressure is 0.048 instead of usual 0.065 For next shot - add 2msec to prepuff |
| Jun 20 2000 09:24:10:857AM | 1000620001 | Dmitri Mossessian | Plasma. DNB valve was disabled and G-side pressure is 0.048 instead of usual 0.065 For next shot - add 2msec to prepuff (19 msec->21 msec) |
| Jun 20 2000 09:41:07:183AM | 1000620002 | Dmitri Mossessian | Fizzle. Current rise too slow. Gas is where I wanted it to be (0.055 mtorr), but perhaps it wants it lower For next shot: return prefill back to 19 msec. Drop Bz (IC_EF4 -1290 -> 1300) |
| Jun 20 2000 09:53:43:733AM | 1000620003 | Dmitri Mossessian | Plasma. Startup is just like 1000620001. For next shot: no changes |
| Jun 20 2000 10:47:20:013AM | 1000620004 | Dmitri Mossessian | Plasma. For next shot: no changes |
| Jun 20 2000 10:49:22:950AM | 1000620005 | Dmitri Mossessian | Plasma. For next shot: pulled Z-XL down 8 mm at 1.1 sec for F-probe |
| Jun 20 2000 11:00:04:873AM | 1000620006 | Dmitri Mossessian | Plasma. Z_XL flattened as expected. For next shot: no changes |
| Jun 20 2000 11:22:24:933AM | 1000620007 | Dmitri Mossessian | Plasma. For next shot: no changes |
| Jun 20 2000 11:49:54:200AM | 1000620008 | Dmitri Mossessian | Plasma. For next shot: no changes |
| Jun 20 2000 12:58:36:763PM | 1000620009 | Dmitri Mossessian | Plasma. For next shot: no changes |
| Jun 20 2000 12:58:42:343PM | 1000620010 | Dmitri Mossessian | Plasma. For next shot: no changes |
| Jun 20 2000 12:58:49:890PM | 1000620011 | Dmitri Mossessian | Plasma. For next shot: no changes |
| Jun 20 2000 12:58:53:717PM | 1000620012 | Dmitri Mossessian | Plasma. For next shot: no changes |
| Jun 20 2000 01:39:10:140PM | 1000620013 | Dmitri Mossessian | Plasma. For next shot: flatten current at .7MA between 1 and 1.3 sec. Extended Z_XL slope to 1.35 sec (hoping that in reality it'll stay constant) |
| Jun 20 2000 01:52:56:357PM | 1000620014 | Dmitri Mossessian | Plasma. Disrupted 30 msec after Ip was supposed to go flat. It's not clear, whether Ip actually flatten. For next shot: rise current flattop to 735000A and extend it back to .99 sec to keep const rampdown rate before. |
| Jun 20 2000 02:20:38:093PM | 1000620015 | Dmitri Mossessian | Plasma. Flattop OK. For next shot: get rid of Ip flattop. Try to make plasma inside limited CLEARIN -0.01 -> -.025, keeping the right gap const (RCUR down by 0.007) |
| Jun 20 2000 02:30:57:700PM | 1000620016 | Dmitri Mossessian | Plasma. Not really limited yet For next shot: make CLEARIN more negative (-.035) |
| Jun 20 2000 02:48:06:480PM | 1000620017 | Dmitri Mossessian | Fizzle. Bz too low. For next shot: add 15A to IC_EF4 |
| Jun 20 2000 03:04:59:293PM | 1000620018 | Dmitri Mossessian | Fizzle. Bz now seems to be too high. Br has been too high on last 2 shots. For next shot: take 15A off IC_EF4. Lower Br 0.5mT |
| Jun 20 2000 03:32:46:763PM | 1000620019 | Dmitri Mossessian | Plasma. Slow current rise. For next shot: No changes in segment 1. Lower target density to 1.7e20 CLEARIN more negative (-.05) and change RCUR accordingly |
| Jun 20 2000 03:52:45:797PM | 1000620020 | Dmitri Mossessian | Plasma. Right gap is too large (3 cm). For next shot: desable J-bottom gas valve, increase RCUR 1 cm to make right gap smaller |
| Jun 20 2000 04:09:15:200PM | 1000620021 | Dmitri Mossessian | wolfe sitting in for Dmitri- Shot 21 is ok, but right gap is too small early. next shot: Rcur fro .665 to .662 at 0.5sec, to increase right gap by 6mm early. |
| Jun 20 2000 04:32:25:030PM | 1000620022 | Dmitri Mossessian | Plasma. Disrupted at .55 sec. One of the reasons may be that it gets to q95=3 at that point For next shot: lower max Ip to 0.9 MA |
| Jun 20 2000 04:43:24:560PM | 1000620023 | Dmitri Mossessian | Plasma. Disrupted at 1 sec at density limit. For next shot: no changes |
| Jun 20 2000 05:00:22:513PM | 1000620024 | Dmitri Mossessian | Last shot. Plasma. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:07:15:827AM | Plasma | Ok | |
| 2 | 09:28:18:513AM | Plasma | Ok | |
| 3 | 09:42:59:730AM | Plasma | Ok | |
| 4 | 10:03:12:060AM | Plasma | Ok | |
| 5 | 10:24:26:170AM | Plasma | Ok | |
| 6 | 10:48:17:593AM | Plasma | Ok | |
| 7 | 11:07:32:357AM | Plasma | Ok | |
| 8 | 11:28:52:140AM | Plasma | Ok | |
| 9 | 11:49:48:513AM | Plasma | Ok | |
| 10 | 12:12:37:933PM | Plasma | Ok | |
| 11 | 12:32:42:077PM | Plasma | Ok | |
| 12 | 12:56:02:577PM | Plasma | Ok | |
| 13 | 01:18:31:480PM | Plasma | Ok | |
| 14 | 01:40:09:530PM | Plasma | Ok | |
| 15 | 02:00:10:547PM | Plasma | Ok | |
| 16 | 02:22:25:467PM | Plasma | Ok | |
| 17 | 02:40:42:980PM | Plasma | Ok | |
| 18 | 02:58:10:560PM | Plasma | Ok | |
| 19 | 03:15:49:280PM | Plasma | Ok | |
| 20 | 03:37:17:653PM | Plasma | Ok | |
| 21 | 03:58:07:653PM | Plasma | Ok | |
| 22 | 04:17:21:170PM | Plasma | Ok | |
| 23 | 04:37:48:373PM | Plasma | Ok | |
| 24 | 04:57:38:590PM | Plasma | Ok | |