| Miniproposals | ||||||||||
|
| Operators | |
| Session leader(s): | Chris Boswell |
| Physics operator(s): | Bill Rowan |
| Engineering operator(s): | Bill Parkin,Bill Byford |
| Engineering Operator Run Comment |
| MP294 Molecular Recombination: SL:Boswell; PO:Rowan; EO:Byford/Parkin |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:26:383PM |
| Author: To Be Determined |
| MP294: Divertor Continuum Emission Studies Physics Operator: W. Rowan Session Leader: C. Boswell Purpose of Experiments: - To obtain high resolution images of D_gamma and continuum emission in the divertor at various densities - To determine spatial relation of the D_gamma and continuum emissivities - To test the hypothesis of molecular recombination as the cause of the "anomalous" continuum emission in the divertor Shot sequence plan: All of the following shots will have the magnetic configuration from shot 1010612001, with a possible shift of the strike-point downward slightly. Shot 1: Ramp nl_04 from 0.7e20 m^-2 to 1.5e10 m^-2 during the flat-top Shot 2: Keep the density at a constant nl_04 of 1.2e20 m^-2 Shot 3: Repeat shot 2 with strong puffing of helium in the middle of the flat-top. Shot 4: Repeat shot 2 except during the flat-top continuously try to increase the concentration of helium while keeping nl_04 constant. It should be noted that this run will have considerable helium in the discharges, and that shot 4 may require several attempts until the desired concentration is achieved. Results: As far as the scheduled miniproposal is concerned the run was successful. The continuum between 420nm and 430nm during the mostly helium shot drops by a factor of about 25%, while the deuterium lines drops by approximately a factor of 4 to 10. This modest decrease in the continuum when compared to the significant decrease the deuterium leads us to believe that the continuum is not due to molecular recombination. The end of the day was spent ramping the separatrix associated with the upper x-point toward the separatrix associated with the lower x-point until the plasma goes upper null. This was done to determine whether or not the emission band seen at the inner wall is associated with the inboard-most separatrix. All results seem to indicate that the emission follows the inboard-most separatrix, suggesting different radial transport characteristics between the regions defined by the inboard-most separatrix. Shot Summary: 001 -- Plasma. nl_04 = 0.8e20 m^-2 at 1.000 seconds. 002 -- Plasma. nl_04 ramp from 0.8e20 to 1.2e20 m^-2 003 -- No Power Shot. 004 -- Plasma. - Perturbations seen on density are due to oscillating flappers. - No obvious detachment on the outer probe - Rather than continue to increase density at this current we will drop the current to 0.8 MA and again do the density ramp 005 -- Plasma. - Perturbations seen on density are due to oscillating flappers. - Detachment occurs at 1.2 sec, nl_04=1.3e20 m^-2 006 -- Plasma. - Density flat-top begins at 1.2 sec - Perturbations seen on density are due to oscillating flappers. - Detachment occurs at 1.2 sec, nl_04=1.3e20 m^-2 007 -- Plasma. - Density flat-top begins at 0.8 sec - Density flat-top begins at 0.8 sec - Perturbations seen on density are due to oscillating flappers 009 -- Plasma. - Density flat-top begins at 0.8 sec - Got what was requested. Clearly not enough helium to affect the emission. 010 -- Plasma. - Density flat-top begins at 0.8 sec - Mostly helium plasma. Deuterium emission in the divertor drops to a level below what the camera can see. - The continuum is still seen on the camera except slightly less intense. 011 -- Plasma. - Repeat of 10. 012 -- Plasma. - Repeat of 10. 013 -- Plasma. - This was used to get default parameters for the upcoming shots 014 -- Plasma. - Only change is in density to nl_04 = 0.9e20 m^2 015 -- Plasma. - Successful secondary separatrix scan - The DANT camera clearly shows a band of emission sweep towards the plasma and and stop - The plasma does go upper null later in the shot 016 -- Plasma. - Successful secondary separatrix scan - The DANT camera clearly shows a band of emission sweep towards the plasma and and stop - The plasma does go upper null later in the shot - Inner gap ~ 2cm, outer gap ~ 1.5cm 017 -- No power shot. 018 -- Plasma. - Successful secondary separatrix scan - The DANT camera clearly shows a band of emission sweep towards the plasma and and stop - The plasma does not go upper null and the SSEP stops at 0.35cm from the primary separatrix 019 -- Plasma. - Successful secondary separatrix scan - The DANT camera clearly shows a band of emission sweep towards the plasma, but the emission gets lost when we go upper null. |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:37:13:223PM |
| Author: To Be Determined |
| PhysOp Summary for Wednesday, June 13, 2001 Experiment: MP294 Molecular recombination in the C-Mod divertor. SL: Boswell PO: Rowan EO: Parkin/ Engineering setup ----------------- ECDC in D2 overnight Run starts at 9:00AM Power systems as on 1010612011. Gas setup: fill B-top with 6 psi of D2 Hybrid enabled (PG4) fill B-side lower with 1 psi of Ar Hybrid enabled (PG1) fill B-side upper with 6 psi of He Hybrid enabled (PG2) fill C-side with 30 psi of D2 Hybrid enabled (PG3) fill J-bottom with 6 psi of He Hybrid DISABLED (PG5) Enable the following gate valves: ECE, DNB, and VUV. Brief run plan: The run will be for molecular recombination MP294. We will start with shot 1010612011. There will be several density ramps on subsequent shots. Helium will be puffed on some shots to increase helium to a significant level. If it can be accommodated without problems to the other activities, we will attempt to finish the shape development for MP287, ASDEX comparison. Results ------- The SL added a scan of the secondary separatrix to the run plan. This was to be run if there was time at the end of the day. We completed this as well as density ramps in D2 and plasmas in He. For the first shot of the day, shot 1010612011 was loaded. Density ramps and plateaus The density ramps were on shots 002 through 005. The ramp was from approximately NL_04 = 0.7E+20 to 1.57E+20. The last shot had a current of approximately 0.76 MA. The others were nearer 1 MA. Shots 006 and 007 had density plateaus. DNB affect on prefill The DNB started the day firing after 1 s. When fired in this time range, the beam has minimal effect on the prefill and hence on breakdown. However on shot 008, the firing time was moved to 0.5s to avoid the high neutral pressure at later times. The prefill pulse was reduced from 20 to 24 ms so that breakdown would not be affected. He shots A 100 ms pulse of helium was puffed at 1.1 s on shot 009. For shots 010 through 012, helium was substituted for D2 as the gas used for feedback control of the density after 100 ms. D2 prefill was used for these shots to avoid affecting breakdown. The discharges ran well and there were no mods other than subsituting helium for deuterium at the C-side valve. Secondary separatrix scan. The model shot was 990226020. For that experiment, Steve developed a separatrix scan. He modified his setup for the current experiment. The STRKIN wire was loaded from that shot and changed slightly. The scans are on shots 015, 016, 018, and 019. 015 and 016 are scans from lower single null to double null. 018 is a scan from the lower single null to the just short of a double null. Shot 019 may be a scan from lower single null to an upper null. Computer problems Lost one shot due to the customary 4012 init problem early in the run. This is a hardware problem which the owners are working to repair. The module was again turned off, and Josh agreed to rewrite the driver to avoid the peculiarities of the 4012 causing problems for the entire group. Scorecard --------- Plasmas 17 Fizzles 0 Duds 0 Engineering/data acquisition problems 2 Total 19 |
| Session Leader Comments | |||
| Jun 13 2001 09:49:51:153AM | Chris Boswell | MP294: Divertor Continuum Emission Studies Physics Operator: W. Rowan Session Leader: C. Boswell Purpose of Experiments: - To obtain high resolution images of D_gamma and continuum emission in the divertor at various densities - To determine spatial relation of the D_gamma and continuum emissivities - To test the hypothesis of molecular recombination as the cause of the "anomalous" continuum emission in the divertor Shot sequence plan: All of the following shots will have the magnetic connfiguration from shot 1010612011, with a possible shift of the strike-point downward slightly. Shot 1: Ramp nl_04 from 0.7e20 m^-2 to 1.5e10 m^-2 during the flat-top Shot 2: Keep the density at a constant nl_04 of 1.2e20 m^-2 Shot 3: Repeat shot 2 with strong puffing of helium in the middle of the flat-top. Shot 4: Repeat shot 2 except during the flat-top continuously try to increase the concentration of helium while keeping nl_04 constant. It should be noted that this run will have considerable amounts of helium in the discharges, and that shot 4 may require several attempts until the desired concentration is achieved. | |
| Jun 13 2001 09:42:08:517AM | 1010613001 | Chris Boswell | Plasma. Next Shot: ramp nl_04 from 0.8e20 to 1.2e20 |
| Jun 13 2001 09:50:55:843AM | 1010613002 | Chris Boswell | Plasma. Next Shot: ramp nl_04 to 1.5e20 m^-2 |
| Jun 13 2001 10:02:24:813AM | 1010613003 | Chris Boswell | No Power shot. Next Shot: ramp nl_04 to 1.5e20 m^-2 |
| Jun 13 2001 10:36:09:287AM | 1010613004 | Chris Boswell | Plasma. - Perturbations seen on density are due to oscillating flappers. - No obvious detachment on the outer probe - Rather than continue to increase density at this current we will drop the current to 0.8 MA and again do the density ramp Next Shot: Decrease current to 0.8 MA ramp nl_04 to 1.5e20 m^-2 |
| Jun 13 2001 11:09:33:307AM | 1010613005 | Chris Boswell | Plasma. - Perturbations seen on density are due to oscillating flappers. - Detachment occurs at 1.2 sec, nl_04=1.3e20 m^-2 Next Shot: constant nl_04 of 1.3e20 m^-2 |
| Jun 13 2001 11:23:40:093AM | 1010613006 | Chris Boswell | Plasma. - Density flat-top begins at 1.2 sec - Perturbations seen on density are due to oscillating flappers. - Detachment occurs at 1.2 sec, nl_04=1.3e20 m^-2 Next Shot: constant nl_04 of 1.4e20 m^-2 beginning at 0.75 sec |
| Jun 13 2001 11:47:31:413AM | 1010613007 | Chris Boswell | Plasma. - Density flat-top begins at 0.8 sec Next Shot: repeat |
| Jun 13 2001 12:09:31:663PM | 1010613008 | Chris Boswell | Plasma. - Density flat-top begins at 0.8 sec - Perturbations seen on density are due to oscillating flappers Next Shot: Repeat with helium puff beginning at 1.1 sec and staying on for 100 ms. |
| Jun 13 2001 12:38:45:367PM | 1010613009 | Chris Boswell | Plasma. - Density flat-top begins at 0.8 sec - Got what was requested. Clearly not enough helium to affect the emission. Next Shot: Repeat with helium fueling during the shot |
| Jun 13 2001 01:35:07:483PM | 1010613010 | Chris Boswell | Plasma. - Density flat-top begins at 0.8 sec - Mostly helium plasma. Deuterium emission in the divertor drops to a level below what the camera can see. - The continuum is still seen on the camera except slightly less intense. Next Shot: Repeat with changes to the cameras. |
| Jun 13 2001 02:08:23:690PM | 1010613012 | Chris Boswell | Plasma. - Density flat-top begins at 0.8 sec - Mostly helium plasma. Deuterium emission in the divertor drops to a level below what the camera can see. - The continuum is still seen on the camera except slightly less intense. Next Shot: Changing to attempt a secondary separatrix scan in deuterium |
| Jun 13 2001 02:39:10:990PM | 1010613013 | Chris Boswell | Plasma. - This was used to get default parameters for the upcoming shots Next Shot: Change density such that nl_04 = 0.9e20 m^-2 |
| Jun 13 2001 03:01:01:007PM | 1010613014 | Chris Boswell | Plasma. Next Shot: Dynamic secondary separatrix scan |
| Jun 13 2001 03:39:58:723PM | 1010613015 | Chris Boswell | Plasma. - Successful secondary separatrix scan - The DANT camera clearly shows a band of emission sweep towards the plasma and and stop - The plasma does go upper null later in the shot Next Shot: Same experiment except have the outer gap at 1.5cm the inner gap at 2cm and sweep the secondary separatrix from > 1.5cm to 0cm |
| Jun 13 2001 04:11:16:930PM | 1010613016 | Chris Boswell | Plasma. - Successful secondary separatrix scan - The DANT camera clearly shows a band of emission sweep towards the plasma and and stop - The plasma does go upper null later in the shot - Inner gap ~ 2cm, outer gap ~ 1.5cm Next Shot: Same experiment except have secondary separatrix stop at 0.5cm outside the primary separatrix, keeping the plasma lower null. |
| Jun 13 2001 04:17:58:173PM | 1010613017 | Chris Boswell | No power shot. Next Shot: Try again. |
| Jun 13 2001 04:40:57:820PM | 1010613018 | Chris Boswell | Plasma. - Successful secondary separatrix scan - The DANT camera clearly shows a band of emission sweep towards the plasma and and stop - The plasma does not go upper null and the SSEP stops at 0.35cm from the primary separatrix Next Shot: Start lower null move the secondary separatrix until the plasma is double null and then move the new secondary separatrix away from the primary separatrix. |
| Jun 13 2001 05:24:06:650PM | 1010613018 | Chris Boswell | Plasma. - Successful secondary separatrix scan - The DANT camera clearly shows a band of emission sweep towards the plasma, but the emission gets lost when we go upper null. |
| Physics Operator Comments | |||
| Jun 13 2001 08:16:36:917AM | Bill Rowan | Run Plan for Wednesday, June 13, 2001 MP294 Molecular recombination in the C-Mod divertor. SL: Boswell PO: Rowan Engineering setup: ECDC in D2 overnight Run starts at 9:00AM Power systems as on 1010612011. Gas setup: fill B-top with 6 psi of D2 Hybrid enabled (PG4) fill B-side lower with 1 psi of Ar Hybrid enabled (PG1) fill B-side upper with 6 psi of He Hybrid enabled (PG2) fill C-side with 30 psi of D2 Hybrid enabled (PG3) fill J-bottom with 6 psi of He Hybrid DISABLED (PG5) Enable the following gate valves: ECE, DNB, and VUV. Run plan: The run will be for molecular recombination MP294. We will start with shot 1010612011. There will be several density ramps on subsequent shots. Helium will be puffed on some shots to increase helium to a significant level. If it can be accommodated without problems to the other activities, we will attempt to finish the shape development for MP287, ASDEX comparison. | |
| Jun 13 2001 08:28:54:357AM | Bill Rowan | Loaded from shot 1010612011. Did Load /Clean Coldstart completed 13-JUN-2001 08:21:22.41 *************** END COLDSTART ****************** No errors. | |
| Jun 13 2001 09:26:02:587AM | 1010613001 | Bill Rowan | 001. Plasma. Similar to target shot. For the next shot: Will ramp to approx NL_04=1.2e+20 by the end of the shot. |
| Jun 13 2001 09:46:18:007AM | 1010613002 | Bill Rowan | 002. Plasma. NL_04=1.2e+20 as requested Next shot. Increase the ramp to approx NL_04=1.5e+20 by the end of the shot |
| Jun 13 2001 10:17:24:307AM | 1010613003 | Bill Rowan | 003. On this shot, there was a computer hang. Offending module was turned off. |
| Jun 13 2001 10:30:37:653AM | 1010613004 | Bill Rowan | 004. Plasma. NL_04 to a bit less than 1.5e+20. Approx as requested. For the next shot, 0.8MA at request of SL. See SL log. |
| Jun 13 2001 10:43:34:750AM | 1010613005 | Bill Rowan | 005. Plasma. IP approx 0.76MA. NL_04 still rising to 1.5e+20 |
| Jun 13 2001 11:09:12:823AM | 1010613005 | Bill Rowan | For the next shot, level the density out at NL_04=1.3e+20 |
| Jun 13 2001 11:15:30:817AM | 1010613006 | Bill Rowan | 006. Plasma. For the next shot, level the density at 1.3e+20 at 0.75s |
| Jun 13 2001 11:22:01:403AM | 1010613006 | Bill Rowan | Correction by SL: level the density at 1.4e+20 at 0.75s |
| Jun 13 2001 11:51:12:323AM | 1010613007 | Bill Rowan | 007. Plasma. Good shot. For the next shot, move the DNB to 0.5 s for lower pressure Reduce the prefill from 24 ms to 20 ms |
| Jun 13 2001 12:11:32:997PM | 1010613008 | Bill Rowan | 008. Plasma. G-side ratiomatic shows 0.083 mT compared to about 0.07 on previous shots. Next shot. Add an additional helium puff at 1.1s |
| Jun 13 2001 12:17:39:503PM | 1010613008 | Bill Rowan | Helium puff at 1.1s for next shot is 100 ms |
| Jun 13 2001 12:39:00:650PM | 1010613009 | Bill Rowan | 009. Plasma Good shot. Not enough He for the SL For next shot: Replace D2 in c-side with He. |
| Jun 13 2001 01:19:54:430PM | 1010613010 | Bill Rowan | 010. Plasma. Made the transition to He. The manifold pressure was approximately 16 pounds. Next shot. Repeat |
| Jun 13 2001 01:37:59:567PM | 1010613011 | Bill Rowan | 011. Plasma. Next shot. Repeat. |
| Jun 13 2001 01:56:06:780PM | 1010613012 | Bill Rowan | 012. Plasma. Last shot of this Helium series. Replace He with D2 in C-SIde. |
| Jun 13 2001 02:28:51:550PM | 1010613012 | Bill Rowan | Next shot.. Made changes in wire to attempt an upper separatix scan. |
| Jun 13 2001 02:38:57:720PM | 1010613012 | Bill Rowan | 013. Plasma. Next shot. Lower NL_04=0.9e+20 |
| Jun 13 2001 03:01:33:553PM | 1010613012 | Bill Rowan | 14. Plasma. NL_04=0.9e+20 Next shot. Secondary separatrix scan. This is intended as an updated version of 990226020. Using the STRKIN controller. |
| Jun 13 2001 03:46:58:657PM | 1010613015 | Bill Rowan | 015. Plasma. Scan from single null to double null. Next shot. Change outer gap from 1 to 1.5. Change inner gap from 2.5 to 2.0 |
| Jun 13 2001 04:10:32:320PM | 1010613016 | Bill Rowan | 016. Plasma. On this shot, the plasma went from a lower single null to a double null to an upper null. On the following shot, the idea is to reduce the swing so that the configuration stays at double null. |
| Jun 13 2001 04:20:38:380PM | 1010613017 | Bill Rowan | 017. No power shot. |
| Jun 13 2001 04:35:46:200PM | 1010613018 | Bill Rowan | 018. Plasma. |
| Jun 13 2001 04:56:03:687PM | 1010613019 | Bill Rowan | 019. Plasma. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:13:17:597AM | Plasma | Ok | |
| 2 | 09:36:15:850AM | Plasma | Ok | |
| 3 | 09:53:10:113AM | Plasma | Bad | Initialization Problem with Igor |
| 4 | 10:16:37:007AM | Plasma | Bad | EF1L Overvoltage |
| 5 | 10:38:55:073AM | Plasma | Ok | |
| 6 | 11:09:35:620AM | Plasma | Ok | |
| 7 | 11:32:16:560AM | Plasma | Ok | |
| 8 | 11:56:57:067AM | Plasma | Ok | |
| 9 | 12:21:38:793PM | Plasma | Ok | |
| 10 | 12:57:03:690PM | Plasma | Ok | |
| 11 | 01:27:30:737PM | Plasma | Ok | |
| 12 | 01:53:05:010PM | Plasma | Ok | |
| 13 | 02:28:10:393PM | Plasma | Ok | |
| 14 | 02:51:03:900PM | Plasma | Ok | |
| 15 | 03:20:25:833PM | Plasma | Ok | |
| 16 | 03:48:36:127PM | Plasma | Ok | |
| 17 | 04:14:53:077PM | Test | Ok | No power shot , |
| 18 | 04:27:19:033PM | Plasma | Ok | |
| 19 | 04:53:54:950PM | Plasma | Ok | |