| Miniproposals | ||||||||||
|
| Operators | |
| Session leader(s): | Ken Gentle |
| Physics operator(s): | Earl Marmar |
| Engineering operator(s): | Bill Cochran,Gary Dekow,Frank Silva |
| Engineering Operator Run Comment |
| mp#186 Marmer/Silva |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:20:383PM |
| Author: To Be Determined |
| Session Leader Summary 990520 The objective was to inject sufficient quantities of carbon by laser ablation to drive significant, fast reductions in edge temperatues and cause prompt core temperature rises. The effect has been widely observed at low densities; the operating space in CMOD was to be explored. Low powr, low density target plasmas were chosen to begin. Both diverted and limited configurations were run, with no significant differences. 003 -- 800 KA, diverted, 1.0E20 discharge. Initial discharge, no injection 004 -- C Injection at 0.71 s. Edge Te falls 30%. Core heating, but with 10 ms delay; similar for neutron rate. However, the edge cool pulse inverts to prompt heating at inner radii outside the inversion radius. The effects are weak, but all qualitative features are present. 005 -- Lower density, but C injection as "cluster"; weaker effect on edge temperature. 006 -- No plasma 007 -- C injection about half that of shot 004. Weak effects. 008 -- 600 kA, 6E19 line density. C injection as cluster and less than shot 004. Weak cooling only. 009 -- 500 kA limited. No significant injection. 010 -- as shot 009 011 --No plasma 012 -- Injection of CaF2 for test. Small increment in radiated power; no effect on Te. 013 -- Return to 800 kA diverted discharges. No significant C injection. Natural injections at 0.75 and 1.0 caused cooling only 014 -- Natural injection at 0.84 only perturbation. 015 -- Similar to shot 004, but less carbon injection and weaker effects on temperature 016 -- Density raised to 1.5E20. Almost no effect on Te. Best proof that effect vanishes at high density. 017 -- Density returned to 1.0E20, but no significant C injection. 018 -- No injection 019 -- Very small injection; little effect. 020 -- Small injection; small effects. 021 -- 1.2 MA, 2.0E20 density. Modest C injection, but no significant effect on Te. (Effect vanishes at higher densities and powers.) H-mode at 0.95. 022 -- 500 kA, density 1.0E20. Small C injection, but some temperature effects. 023 -- Disruption 024 -- 400 kA. Small C injection but some effect on Te. Weak, but clear evidence of prompt interior heating was obtained. The effect disappears at higher density and is strongest at low currents (low power.) Better, more conclusive experiments will require larger carbon injections: prompt peak radiated power on the 2pi bolometer greater than the 300 kW maximum in this series. |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:37:01:350PM |
| Author: To Be Determined |
| Physop summary, 990520 PO Marmar SL Gentle EO Silva/Cochran/DeKow Engineering Setup and Run Plan for 990520 MP186: Perturbation test of non-local transport Load from 990519009 2 hours of ECDC in deuterium before the run TF under hybrid control. After a slow start (OH2 commutation problems on shot 1, gas plenum problems before the run) the machine ran well; there were no fizzles, and only 1 shot disrupted. We explored a range of densities, currents, and shapes. The impurity injector seemed to be working pretty well with carbon at the beginning of the run, but ran into some trouble later, with none of the edge cooling perturbations being as large as the session leader desired. A number of shots did show edge cooling followed by modest core heating. The highest current shot, 21, was at 1.2 MA and had a clear transition into ohmic H-mode shortly after 0.9 sec. Ip and TF rampdown began at 1 second. There were rumors of quasicoherent fluctuations from reflectometry; this may have been an ohmic EDA H-Mode; q_95 was 3.7; kappa was 1.7; tau_E transiently approached 0.1 seconds. Scorecard: 20 plasmas 2 duds 2 tests ---------- 24 shot cycles |
| Session Leader Comments |
| Physics Operator Comments | |||
| May 20 1999 07:47:21:763AM | Earl Marmar | Engineering Setup and Run Plan for 990520 MP186: Perturbation test of non-local transport Load from 990519009 2 hours of ECDC in deuterium before the run TF under hybrid control. Gas setup: B-top - 6 psi of D2 Hybrid enabled B-side lower - 1 psi of Ar Hybrid DISABLED B-side upper - as is, HYBRID DISABLED C-side - 30 psi D2 Hybrid enabled J-bottom - as is Hybrid DISABLED ECE,VUV gate valves enabled if vacuum conditions ok. We are aiming to start at 8:00 am First shot will be a fiducial, 800 kA, diverted shot Once this is established, attempt to reproduce conditions from 980108, the last time this MP was run. This means 0.5 MA, inner-wall limited, circular discharges at nl_04 around 3e20 or below. If the carbon injections are not working we will switch to backup mini-proposal MP213A Te Fluctuations (ohmic) with John Heard as session leader. | |
| May 20 1999 07:51:20:857AM | 990520001 | Earl Marmar | coldstart all matrices respond no errors in log load from 990519009 |
| May 20 1999 09:12:21:263AM | 990520001 | Earl Marmar | Dud OH2 upper did not commutate |
| May 20 1999 10:04:18:467AM | 990520002 | Earl Marmar | OH2 commutation test seems ok |
| May 20 1999 10:26:19:717AM | 990520003 | Earl Marmar | B_R offset to .001 from .003 plasma B_R still looks positive |
| May 20 1999 10:54:55:140AM | 990520004 | Earl Marmar | B_R offset to 0.000 from 0.001 Try for carbon injection with the laser at 0.7 seconds plasma clear evidence of core heating following the carbon injection \Z_bright also goes up, as does the neutron rate |
| May 20 1999 11:12:03:373AM | 990520005 | Earl Marmar | lower nl_04 target to 6e19 plasma nl_04=7e19 |
| May 20 1999 11:50:14:560AM | 990520006 | Earl Marmar | repeat dud no toroidal field |
| May 20 1999 11:57:52:077AM | 990520007 | Earl Marmar | attempt to repeat 5 plasma good shot |
| May 20 1999 12:15:08:403PM | 990520008 | Earl Marmar | I_p = 600 kA move ZXL up slightly to reduce elongation a bit plasma q_95=5.6 |
| May 20 1999 12:40:16:793PM | 990520009 | Earl Marmar | program for inner wall limited, circular 500 kA plasma got what we asked for |
| May 20 1999 12:57:40:233PM | 990520010 | Earl Marmar | nl_04 to 6e19 prop gain on wire 10 RCUR increased from 2 to 3 plasma there is a small radial oscillation, which interferes with cold-pulse analysis |
| May 20 1999 01:15:58:687PM | 990520011 | Earl Marmar | increase derivative gain on wire 10 RCUR from 0.5 to 1. shot didn't go through; power supplies were left in standby after power room access went from check to recool |
| May 20 1999 01:54:29:560PM | 990520012 | Earl Marmar | try again shooting CaF_2 with the laser blow-off system this time plasma not much effect of the injection |
| May 20 1999 02:06:55:717PM | 990520013 | Earl Marmar | reload segment 2 from shot 004 attempt to shoot carbon plasma no evidence of the carbon injection nice natural injection at 1.0 seconds |
| May 20 1999 02:24:00:013PM | 990520014 | Earl Marmar | repeat plasma no evidence of carbon |
| May 20 1999 02:44:32:233PM | 990520015 | Earl Marmar | repeat plasma got some carbon and modest core heating |
| May 20 1999 02:56:42:310PM | 990520016 | Earl Marmar | nl_04 to 1.5e20 plasma |
| May 20 1999 03:03:54:123PM | 990520016 | Earl Marmar | Shot 016 Plasma nl04 ~ 1.6e20 |
| May 20 1999 03:25:57:890PM | 990520017 | Earl Marmar | move TF rampdown to start at 1.0 s nl_04 to .8e20 plasma no carbon |
| May 20 1999 03:54:15:170PM | 990520018 | Earl Marmar | add a little derivative gain to nl04 feedback plasma no obvious carbon |
| May 20 1999 04:24:35:983PM | 990520019 | Earl Marmar | repeat plasma some carbon |
| May 20 1999 04:25:01:860PM | 990520020 | Earl Marmar | repeat plasma a little more carbon |
| May 20 1999 05:03:34:263PM | 990520021 | Earl Marmar | Ip=1.2 MA plasma carbon, but no core heating Ohmic H-mode starting at about 0.9 seconds looks like EDA; reports of quasi-coherent fluctuation from reflectometer clear pedestal on z-meter array |
| May 20 1999 05:04:19:763PM | 990520022 | Earl Marmar | 0.5 MA plasma carbon |
| May 20 1999 05:17:46:623PM | 990520023 | Earl Marmar | .4 MA plasma disrupt at 0.59 sec; too elongated for the current |
| May 20 1999 05:36:51:780PM | 990520024 | Earl Marmar | raise RXL decrease clearin plasma carbon slight lurch at 1 second; briefly touches inner wall |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:01:03:717AM | Plasma | Bad | OH2U failed to commutate |
| 2 | 10:01:30:797AM | Test | Ok | OH2U,OH2L PLC 10kamp commutation test only |
| 3 | 10:18:53:390AM | Plasma | Ok | No Faults, OH2U commutated |
| 4 | 10:35:00:670AM | Plasma | Ok | no faults/plasma |
| 5 | 10:54:43:013AM | Plasma | Ok | No faults |
| 6 | 11:13:49:950AM | Plasma | Bad | No TF , All other supplys fired okay |
| 7 | 11:49:57:763AM | Plasma | Ok | No Faults |
| 8 | 12:07:23:513PM | Plasma | Ok | No faults |
| 9 | 12:28:26:670PM | Plasma | Ok | No faults |
| 10 | 12:47:26:920PM | Plasma | Ok | No faults |
| 11 | 01:10:51:467PM | Test | Ok | No power test shot for camac sync. |
| 12 | 01:33:45:903PM | Plasma | Ok | No faults |
| 13 | 01:51:44:983PM | Plasma | Ok | No faults |
| 14 | 02:12:42:140PM | Plasma | Ok | No faults |
| 15 | 02:33:29:263PM | Plasma | Ok | No Faults |
| 16 | 02:51:54:610PM | Plasma | Ok | No Faults |
| 17 | 03:14:04:640PM | Plasma | Ok | No Faults |
| 18 | 03:33:07:437PM | Plasma | Ok | No Faults |
| 19 | 03:52:16:530PM | Plasma | Ok | No Faults |
| 20 | 04:12:08:937PM | Plasma | Ok | No Faults |
| 21 | 04:30:15:747PM | Plasma | Ok | No Faults |
| 22 | 04:50:10:093PM | Plasma | Ok | No Faults |
| 23 | 05:09:22:967PM | Plasma | Ok | No Faults |
| 24 | 05:27:29:187PM | Plasma | Ok | No Faults |