| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Chris Boswell |
| Physics operator(s): | Earl Marmar |
| Engineering operator(s): | Bill Parkin,Bill Cochran |
| Engineering Operator Run Comment |
| MP 223 Recombination and Ionization in the Alcator CMOD Divertor.Boswell |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:24:913PM |
| Author: To Be Determined |
From: MAX::BOSWELL Date: 21-SEP-2000 14:30:05 Subj: run_summary_1000920 MP223: Recombination and Ionization in the Alcator C-Mod divertor Physics Operator: E. Marmar Session Leader: C. Boswell Engineering Leader: B. Cochran, B. Parkin Goals: - To characterize the magnitude, location, and evolution of the volume recombination and ionization in the Alcator C-Mod divertor in 1. Ohmically detached plasmas 2. EDA H-mode plasmas 3. flapper open and flapper closed discharges - Obtain spatial temperature and density profiles using D_gamma to continuum profile ratios for the above listed conditions The proposed shot sequence: Part 1 - 5 ohmic shots in which the maximum density is raised in steps of 0.3x10^20 m^-2 from nl_04 = 1.0x10^20 m^-2 on shot 1 to nl_04 = 2.2x10^20 m^-2 on shot 5. All of these shots will be 800 kA, and diverted. Begin using shot 1000908001. Part 2 - 5 shot repeat of the above shots with different filters in the cameras Part 3 - 2 shots of a long EDA (one shot with each set of filters) Begin using shot 1000913001 with the change of 800 kA instead of 1.0 MA for plasma current. Part 4 - 2 shots with the flappers open, using the best shot from the first 10. Part 5 - 4 shots of attached plasmas. Two with flappers open, and two with flappers closed. Changing filters in the middle. Results - Essentially Parts 1-3 were accomplished successfully. Simultaneaous images in divertor D_alpha and D_gamma emission were recorded for the following sets of conditions - the inner leg attached/outer leg attached - EDA H-Mode (Shots 022, 023) - the inner leg detached/outer leg attached (Shots 005, 012 and 017 up to 0.62 s) - inner leg detached/outer leg detached (Shots 005, 012, 014, 015, 017, 020) Under the same conditions, simultaneaous images in D_gamma and "continuum" emission were recorded. (The "continuum" emission covers the wavelength region between D_gamma and D_delta.) We did not get to Parts 4 and 5. Thus no flapper "open" shots were obtained. The initial observations from this run include: 1) Detachment on the outer leg was observed by the cameras as a region of emission that extends up the outer leg (seen with all three filters) 2) There were no obvious differences in the locations of the D_alpha, D_gamma, and "continuum" emission regions during any conditions. (2-D inversions are being generated) 3) During EDA H-modes the emission (D_alpha, D_gamma, and "continuum") changes from being located at the outer strike-point and weakly on the inner nose to no observed emission on the outer leg or strike-point and strong emission on the inner nose. 4) Absolutely calibrated 2-D profiles are being generated for all shots in this run. The shot-by-shot description follows: 001 dud 002 fizzle 003 plasma, but not diverted, limited on outer limiter 004 good shot, camera D_gamma OK, D_alpha too bright 005 good shot - NL_04 to 1.29e20, camera D_gamma & D_alpha OK 006 dud 007 fizzle 008 dud 009 dud 010 fizzle 011 dud 012 good shot - repeat of 005 - NL_04 to 1.30e20. Outer divertor detaches at ~0.63 s. camera D_gamma & D_alpha OK 013 fizzle 014 good shot - NL_04 to 1.54e20. Outer divertor detaches at ~0.41 s. camera D_gamma & D_alpha OK 015 good shot - NL_04 to 1.85e20. Outer divertor detaches at ~0.41 s. Poloidal detachement at 1.335 s. camera D_gamma & D_alpha OK 016 not useful - NL_04 to 2.35e20. Poloidal detachement pretty much the entire shot 017 good shot - repeat of 012 - NL_04 to 1.32e20. Outer divertor detaches at ~0.63 s. camera D_gamma & "continuum" OK 018 not useful - NL_04 to 1.69e20. MARFE at the top of the machine 019 strong fizzle 020 good shot - repeat of 014 - NL_04 to 1.45e20. Outer divertor detaches at ~0.4 s. camera D_gamma & "continuum" OK 021 not useful - NL_04 to 1.81e20. MARFE at the top of the machine 022 good shot - EDA H-mode - NL_04 to 1.55e20. Inner divertor attached some of the time (I think) camera D_gamma & D_alpha OK 023 good shot - repeat of 022 - EDA H-mode - NL_04 to 1.55e20. Inner divertor attached some of the time (I think) camera D_gamma & "continuum" OK |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:37:12:083PM |
| Author: To Be Determined |
| Physop summary 1000920 MP 223 Recombination and ionization in the divertor. SL Boswell PO Marmar Engineering setup for 1000919 Power supplies as on 1000908001, an 800kA, 5.2 tesla diverted discharge. Overnight ECDC in Deuterium, stopping 1-2 hours prior to the run. Operators should be prepared for between shot ECDC The first half of the run will be ohmic, then a few EDA H-mode shots, and finally more ohmic. ICRF Power: D+E approx 2 MW, from 0.6 to 1.4 s Gas setup - fill B-top with 6 psi of D2 Hybrid enabled fill B-side lower with 1 psi of Ar Hybrid enabled fill C-side with 30 psi of D2 Hybrid enabled The following gate valves should be enabled assuming no vacuum problems: ECE, VUV Run begins at 9:00 and ends at 17:00 First shot to be a repeat of 1000908001, but at 5.4 Tesla, instead of 5.2, and I_P rampdown started at 1.1 s This was a somewhat difficult run from the physop point of view. After 1 power supply dud (no EF1 upper) and 1 fizzle (B_R too low), we had 3 plasmas in a row. Shot 6 was a dud, for no apparent reason. Raising the fill led to a late breakdown fizzle on shot 7. This was followed by various field and fill changes which gave 3 more duds and 1 more late breakdown fizzle. Lowering the fill pressure by 3 msec from where we had started gave a plasma on shot 12. Shot 13 fizzled (B_R too positive), and then we had 9 good shots plus 1 very early disruption (80 kA on the rise, lost vertically). The last shot (23) was terminated by a disruption just after the DNB turned off, by what turned out to be a large hole in the DNB bellows which brought the machine up to >100 Torr room air. The duds are troubling, since there was nothing obviously wrong with the magnetics nor anything else that we could figure out to explain them. Scorecard 1 P.S. dud 4 unexplained duds 4 fizzles (2 with very late B.D.) 14 plasmas (1 very early disruption) __________ 23 data system cycles |
| Session Leader Comments | |||
| Sep 20 2000 10:39:49:937AM | Chris Boswell | The proposed Run Plan for 1000920: MP223: Recombination and Ionization in the Alcator C-Mod divertor Physics Operator: E. Marmar Session Leader: C. Boswell Engineering Leader: B. Cochran Goals: - To characterize the magnitude, location, and evolution of the volume recombination and ionization in the Alcator C-Mod divertor in 1. Ohmically detached plasmas 2. EDA H-mode plasmas 3. flapper open and flapper closed discharges - Obtain spatial temperature and density profiles using D_gamma to continuum profile ratios for the above listed conditions The proposed shot sequence: - 5 ohmic shots in which the maximum density is raised in steps of 0.3x10^20 m^-2 from nl_04 = 1.0x10^20 m^-2 on shot 1 to nl_04 = 2.2x10^20 m^-2 on shot 5. All of these shots will be 800 kA, and diverted. Begin using shot 1000908001. - 5 shot repeat of the above shots with different filters in the cameras - 2 shots of a long EDA (one shot with each set of filters) Begin using shot 1000913001 with the change of 800 kA instead of 1.0 MA for plasma current. - 2 shots with the flappers open, using the best shot from the first 10. - 4 shots of attached plasmas. Two with flappers open, and two with flappers closed. Changing filters in the middle. | |
| Sep 20 2000 10:41:43:153AM | 1000920001 | Chris Boswell | dud |
| Sep 20 2000 10:42:02:500AM | 1000920002 | Chris Boswell | fizzle |
| Sep 20 2000 10:44:58:390AM | 1000920003 | Chris Boswell | plasma, but not diverted. Limited on the outer limiter. This happened because we asked that shot 1000908001 be loaded, which was also limited on the outer limiter. |
| Sep 20 2000 11:00:43:390AM | 1000920004 | Chris Boswell | Good shot - after loading shot 1000908024. Good D_gamma on camera, D_alpha is too bright |
| Sep 20 2000 11:37:39:530AM | 1000920005 | Chris Boswell | Good shot - repeat of 004 - NL_04=1.29e20 Good D_gamma and D_alpha on camera - |
| Sep 20 2000 11:37:47:293AM | 1000920006 | Chris Boswell | dud |
| Sep 20 2000 12:42:57:233PM | 1000920007 | Chris Boswell | fizzle |
| Sep 20 2000 12:43:25:780PM | 1000920008 | Chris Boswell | dud |
| Sep 20 2000 12:44:17:403PM | 1000920009 | Chris Boswell | dud |
| Sep 20 2000 01:02:31:043PM | 1000920010 | Chris Boswell | fizzle |
| Sep 20 2000 01:02:45:700PM | 1000920011 | Chris Boswell | dud |
| Sep 20 2000 04:42:15:560PM | 1000920012 | Chris Boswell | Good shot - repeat of 005 - NL_04=1.30e20. Outer divertor detaches at ~0.63 s. Good D_gamma and D_alpha on camera |
| Sep 20 2000 02:05:38:373PM | 1000920013 | Chris Boswell | fizzle |
| Sep 20 2000 02:13:47:060PM | 1000920014 | Chris Boswell | Good shot - NL_04 to 1.54e20, detaches at 0.4 s Good D_gamma and D_alpha on camera |
| Sep 20 2000 03:10:21:123PM | 1000920015 | Chris Boswell | Good shot - NL_04 to 1.85e20, outer divertor detaches at 0.4 s, poloidal detachment at 1.335 s Good D_gamma and D_alpha on camera |
| Sep 20 2000 02:43:49:997PM | 1000920016 | Chris Boswell | Good shot - NL_04 to 2.35e20, poloidally detached pretty much the entire shot D_gamma and D_alpha were weak on divertor camera |
| Sep 20 2000 04:41:04:250PM | 1000920017 | Chris Boswell | Good shot - repeat of 012 - NL_04 to 1.32e20, before this shot, the D_alpha filter was replaced by the "continuum filter" - looks at the continuum between D_gamma and D_delta. Outer divertor detaches at ~0.62 s Good D_gamma and "continuum" on divertor camera |
| Sep 20 2000 03:09:43:780PM | 1000920018 | Chris Boswell | plasma - supposed to be a repeat of 014, but there was a MARFE at the top of the machine, which resulted in NL_04 going to 1.69e20. D_gamma and "continuum" on divertor camera were not good. |
| Sep 20 2000 04:04:36:513PM | 1000920019 | Chris Boswell | strong fizzle |
| Sep 20 2000 04:06:36:607PM | 1000920020 | Chris Boswell | Good shot - repeat of 014 - NL_04 to 1.45e20, detaches at 0.4 s Good D_gamma and "continuum" on divertor camera. |
| Sep 20 2000 04:09:56:653PM | 1000920021 | Chris Boswell | plasma - supposed to be a repeat of 015, but there was a MARFE at the top of the machine - NL_04 went to 1.81e20. D_gamma and "continuum" were not usable on divertor camera. |
| Sep 20 2000 04:33:51:437PM | 1000920022 | Chris Boswell | Goot shot - EDA H-mode at P_rf=2.4 MW, NL_04 went to 1.55e20. Good D_gamma and D_alpha on divertor camera. |
| Sep 20 2000 04:39:09:090PM | 1000920023 | Chris Boswell | Goot shot - Repeat of 022 EDA H-mode at P_rf=2.4 MW, NL_04 went to 1.55e20. Good D_gamma and "continuum" on divertor camera. |
| Physics Operator Comments | |||
| Sep 20 2000 08:29:31:920AM | Jim Irby | Cold start: rtnode -- data loaded, A matrix responds rtnode -- data loaded, M matrix responds rtnode -- data loaded, PID matrix responds RT_NODE Done 20-SEP-2000 07:41:13.45 Loaded shot 1000908001 Checked that offsets in seg 01 and seg 02 were consistent with yesterday's run Changed prefill gas to 23 ms from 19 ms ---- consistent with yesterday's run Checked that TF and IP rampdowns are at 1.5 s Checked that Ip and Tf are at their requested values NL04 programming changed from 1.1e20 to 1.0e20 | |
| Sep 20 2000 09:51:21:327AM | Earl Marmar | Engineering setup for 1000919 MP223: Recombination and Ionization in the Alcator C-Mod divertor. SL: Chris Boswell Power supplies as on 1000908001, an 800kA, 5.2 tesla diverted discharge. Overnight ECDC in Detuterium, stopping 1-2 hours prior to the run. Operators should be prepared for between shot ECDC The first half of the run will be ohmic, then a few EDA H-mode shots, and finally more ohmic. ICRF Power: D+E approx 2 MW, from 0.6 to 1.4 s Gas setup - fill B-top with 6 psi of D2 Hybrid enabled fill B-side lower with 1 psi of Ar Hybrid enabled fill C-side with 30 psi of D2 Hybrid enabled The following gate valves should be enabled assuming no vacuum problems: ECE, VUV Run begins at 9:00 and ends at 17:00 First shot to be a repeat of 1000908001, but at 5.4 Tesla, instead of 5.2, and I_P rampdown started at 1.1 s | |
| Sep 20 2000 09:57:58:793AM | 1000920001 | Earl Marmar | Jim Irby loaded from 1000908001. Changed TF to -151 kA modified segment 4 to have early rampdown (start rampdown at 1.1 s) segment 2 has original end of flattop (1.5 s) dud; no EF1 upper |
| Sep 20 2000 10:11:42:827AM | 1000920002 | Earl Marmar | no PCS changes fizzle B_R is too negative |
| Sep 20 2000 10:32:13:403AM | 1000920003 | Earl Marmar | add 1 mT to B_R offset plasma |
| Sep 20 2000 10:48:53:310AM | 1000920004 | Earl Marmar | reload segment 2 from 1000908024; turn off segment 4, turn on segment 2 plasma |
| Sep 20 2000 11:19:15:500AM | 1000920005 | Earl Marmar | increase early segment 2 PG3 voltage prog and nl_04 to get density up faster plasma |
| Sep 20 2000 11:39:41:810AM | 1000920006 | Earl Marmar | increase nl_04 prog to 1.5e20 dud fields and fill look ok sparker looks the same as on shot 5 (no effect of fill visible) |
| Sep 20 2000 11:48:48:030AM | 1000920007 | Earl Marmar | add 2 msec to prefill puff fizzle late breakdown |
| Sep 20 2000 12:28:05:390PM | 1000920008 | Earl Marmar | remove 2 msec from prepuff B_R offset reduced by 1 mT to 0.0005 T dud |
| Sep 20 2000 12:30:36:547PM | 1000920009 | Earl Marmar | make EF4 10 amp more negative before t=0 B_R offset to 0.001 from 0.0005 dud |
| Sep 20 2000 12:55:06:327PM | 1000920010 | Earl Marmar | reload shot 5 Jim I. upped the sparker voltage by ~1.5 kV Increase prepuff by 3 msec fizzle, late breakdown |
| Sep 26 2000 05:26:55:107PM | 1000920011 | Earl Marmar | EF4 10 amp more negative dud fields look really nice |
| Sep 20 2000 01:23:36:187PM | 1000920012 | Earl Marmar | lower prepuff by 6 msec to 20 msec plasma B_Z was a little low, almost lost it |
| Sep 20 2000 01:32:33:437PM | 1000920013 | Earl Marmar | nl_04 to 1.5e20 EF4 12 amp less negative fizzle B_R looks slightly too positive breakdown at normal time |
| Sep 20 2000 01:50:12:513PM | 1000920014 | Earl Marmar | B_R offset to .001 from .0015 plasma better looking current rise |
| Sep 20 2000 02:22:59:297PM | 1000920015 | Earl Marmar | nl_04 prog to 1.8e20 J-port will be tried at the end of the flattop plasma Disrupt at end of flattop; various power supplies reaching limits |
| Sep 20 2000 02:23:39:653PM | 1000920016 | Earl Marmar | nl_04 prog to 2.3e20 plasma got the density disrupt at 1.3 seconds |
| Sep 20 2000 02:47:38:920PM | 1000920017 | Earl Marmar | reload segment 2 from shot 12 (nl_04 prog 1.2e20) decrease prepuff 1 msec DNB firing at 1.4 seconds plasma |
| Sep 20 2000 03:09:56:577PM | 1000920018 | Earl Marmar | reload segment 2 from shot 14 reduce prepuff by 2 msec plasma |
| Sep 20 2000 03:43:41:983PM | 1000920019 | Earl Marmar | lower nl_04 prog to 1.4e20 plasma lost it vertically on the way up at 80 kA |
| Sep 20 2000 03:44:34:920PM | 1000920020 | Earl Marmar | repeat with segment 1 from 1000919023, prepuff 17 msec, B_R offset .001, EF4 -1290 plasma |
| Sep 20 2000 04:05:01:890PM | 1000920021 | Earl Marmar | nl_04 to 1.7e20 plasma |
| Sep 20 2000 04:25:40:467PM | 1000920022 | Earl Marmar | go to EDA H-mode part of the run load segment 2 from 1000919002 plasma |
| Sep 20 2000 04:30:07:763PM | 1000920023 | Earl Marmar | no PCS changes plasma |
| Sep 20 2000 04:59:10:763PM | 1000920023 | Earl Marmar | reload segment 2 from shot 12 plasma disrupt at 1.53 sec after the shot, the machine vacuum was lost (>100 Torr) |
| Sep 20 2000 06:50:47:327PM | 1000920023 | Earl Marmar | After the run, it was found that the DNB bellows had developed a hole in one of the convolutions, presumably due to ion impact from the beam itself. The radiated power on this shot increased dramatically about 10 msec before the thermal quench, shortly after the end of the beam pulse. It thus appears that the leak opened up during the shot, and caused the disruption. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:52:06:700AM | Plasma | Bad | EF1U did not fire |
| 2 | 10:06:48:187AM | Plasma | Ok | |
| 3 | 10:21:25:640AM | Plasma | Ok | |
| 4 | 10:40:39:187AM | Plasma | Ok | |
| 5 | 11:03:32:747AM | Plasma | Ok | |
| 6 | 11:27:25:060AM | Plasma | Ok | |
| 7 | 11:41:44:937AM | Plasma | Ok | |
| 8 | 11:54:54:340AM | Plasma | Ok | |
| 9 | 12:15:18:233PM | Plasma | Ok | |
| 10 | 12:38:57:077PM | Plasma | Ok | |
| 11 | 12:56:08:467PM | Plasma | Ok | |
| 12 | 01:11:32:420PM | Plasma | Ok | |
| 13 | 01:26:04:810PM | Plasma | Ok | |
| 14 | 01:39:19:937PM | Plasma | Ok | |
| 15 | 01:56:24:233PM | Plasma | Ok | |
| 16 | 02:16:23:717PM | Plasma | Ok | |
| 17 | 02:37:30:467PM | Plasma | Ok | |
| 18 | 02:51:27:200PM | Plasma | Ok | |
| 19 | 03:13:13:873PM | Plasma | Ok | |
| 20 | 03:29:18:920PM | Plasma | Ok | |
| 21 | 03:48:22:170PM | Plasma | Ok | |
| 22 | 04:06:27:797PM | Plasma | Ok | |
| 23 | 04:25:26:030PM | Plasma | Ok | |