| Miniproposals | ||||||||||
| ||||||||||
|
| Operators | |
| Session leader(s): | Martin Greenwald,Martin Greenwald |
| Physics operator(s): | Ron Parker |
| Engineering operator(s): | Unknown |
| Engineering Operator Run Comment |
| Primary run plan EDA: -MP292, MP253 or as an Alternaterun plan: Density |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:26:400PM |
| Author: To Be Determined |
| Run Summary for 1010612 - mp292, mp253 Session Leader - Greenwald Phys Op - Parker Goal: We will concentrate on the quasi-coherent mode and the transport which results from it. Specifically, the goals are: 1. Look for q resonant effects: Because the mode is seen in regions with strong pressure gradients and relatively low temperatures, work on this problem has focussed on the family of resistive ballooning modes. One important characteristic of these modes is that they are resonant with rational q surfaces. Observation of this resonance would lend support to the hypothesis linking the QC mode to resistive ballooning. 2. Compare particle (and energy) flux convected by the fluctuation with the local particle and power balance. We have only a small amount of data on this so far. We want to collect more data from the fast scanning probe and compare the fluxes inferred from ionization source as measured by the Lyman-alpha array. 3. Verify the extent and radial structure of the quasi-coherent fluctuation and its relation to density and temperature profiles. Also, we can take this opportunity to get more data on the poloidal mode structure. 4. Use the fast tangential camera to look for the EDA using helium puffs and observing the HeII 4686 line. Plan: Start with shot 1000928010. This shot has a 5.3T breakdown, then ramps the field down to 2.5T to get an ohmic h-mode then ramps the field back up to about 4T to raise q and get into EDA. We will vary the depth of the down ramp and the rate of rise of the up ramp to scan q slowly. We will be looking for reproducible changes in qc mode amplitude, frequency or wave number. The principal diagnostic for these studies will be the PCI. The scanning probe will be used to collect detailed fluctuation data. If clear q dependent effects are seen, we will use the probe to study these in greater detail. To verify the q dependence, we will look for the effect with both upgoing and downgoing Bt ramps. Results: We had quite a few shots with ohmic EDA. If there was a q resonance effect it must be subtle. There are changes in mode amplitude and frequency observed. The strongest correlation is with sawteeth. There are other excursions which are not correlated with sawteeth and these need to be carefully compared to the q time histories. We got some data from the probes, edge thomson, and from Lyman alpha for the transport studies, these will take more analysis as well. On shot 10, the scanning probes apparently traversed the entire radial extent of the mode - it was 1-2 mm as found earlier. We had less luck with the fast camera. There was insufficient signal from 4686 (HeII). Shot 009 was a particularly nice example of an ELMfree to EDA transition. Shots for further analysis: 1010614003 1010614004 1010614006 1010614008 1010614009 1010614010 1010614014 1010614015 1010614016 1010614017 |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:37:13:240PM |
| Author: To Be Determined |
| ENGINEERING SETUP: ECDC in D2 overnight **** Run Begins at 8:30 and ends at 3:00 ***** Power systems as on 1010612011 Gas setup: fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar Hybrid enabled (PG1) fill B-side upper with 6 psi He Hybrid enabled (PG2) fill C-side with 30 psi D2 Hybrid enabled (PG3) fill J-Bottom with 6 psi He Hybrid DISABLED(PG5) Enable the following gate valves: ECE, DNB, VUV Run plan for 06/14 (GREENWALD) We need to maintain two options: The primary run will be based on mp292 (q resonances in the quasi-coherent mode) and mp 253 (very low power EDA). This run requires that the PCI diagnostic be fully operational. Since it is not certain that the new laser will be working by tomorrow, we will maintain mp 233a (density limit mechanisms) as a backup. Both are ohmic runs. .................... Primary run plan EDA: - mp292, mp253 For the EDA runs we will concentrate on the quasi-coherent mode and the transport which results from it. Specifically, the goals are: 1. Look for q resonant effects: Because the mode is seen in regions with strong pressure gradients and relatively low temperatures, work on this problem has focussed on the family of resistive ballooning modes. One important characteristic of these modes is that they are resonant with rational q surfaces. Observation of this resonance would lend support to the hypothesis linking the QC mode to resistive ballooning. 2. Compare particle (and energy) flux convected by the fluctuation with the local particle and power balance. We have only a small amount of data on this so far. We want to collect more data from the fast scanning probe and compare the fluxes inferred from ionization source as measured by the Lyman-alpha array. 3. Verify the extent and radial structure of the quasi-coherent fluctuation and its relation to density and temperature profiles. Also, we can take this opportunity to get more data on the poloidal mode structure. 4. Use the fast tangential camera to look for the EDA using helium puffs and observing the HeII 4686 line. Plan: Start with shot 1000928010. This shot has a 5.3T breakdown, then ramps the field down to 2.5T to get an ohmic h-mode then ramps the field back up to about 4T to raise q and get into EDA. We will vary the depth of the down ramp and the rate of rise of the up ramp to scan q slowly. We will be looking for reproducible changes in qc mode amplitude, frequency or wave number. The principal diagnostic for these studies will be the PCI. The scanning probe will be used to collect detailed fluctuation data. If clear q dependent effects are seen, we will use the probe to study these in greater detail. To verify the q dependence, we will look for the effect with both upgoing and downgoing Bt ramps. ............................... Alternate run plan: Density limit mechanisms - mp233a We want to collect more data on the changes in turbulence and transport which have been linked to the density limit. In the previous experiments it was observed that the regime of large coherent fluctuations which normally exists in the far scrape-off, moves inward to the separatrix and intrudes into the closed field line regions as the density limit is reached. We will try to insert the probe more deeply into these plasmas at high densities in order to follow the evolution of the profiles and fluctuations. In particular we will try to assess how far into the main plasma this phenomenon reaches. We will also use this opportunity to obtain more data on the changes in transport that accompany the change in fluctuations. The fast camera will be used to look for any visible changes in the edge turbulence - in particular to watch for progressive movement of the turbulent region as the density is raised. 1000620023 would be a good starting point. As before, the approach will be to produce high density ohmic discharges then to ramp down the plasma current to approach the density limit. This gives us density limit disruptions which are reproducible in time which eases the operation of the fast scanning probe. The B$_T$ programming might need to be altered to allow edge profile measurements until the time of the disruptions. Once the shot is set up, few changes are needed. -- RUN SUMMARY The run went extremely well as far as the machine operation was concerned. The only non-plasma shot was the first, a "shot" that was necessary to reset the system after a hangup. The next 16 shots went off as programmed. The only problem that arose during the run was a stubborn disruption that occurred at q ~ 3 on shots 11-13. This was eliminated by reducing the current by 10%. There was no RF during this run. |
| Session Leader Comments | |||
| Jun 14 2001 08:14:44:017AM | Martin Greenwald | Session Leader: Greenwald Phys Op: Parker Run plan: We need to maintain two options: The primary run will be based on mp292 (q resonances in the quasi-coherent mode) and mp 253 (very low power EDA). This run requires that the PCI diagnostic be fully operational. Since it is not certain that the new laser will be working by tomorrow, we will maintain mp 233a (density limit mechanisms) as a backup. Both are ohmic runs. .................... Primary run plan EDA: - mp292, mp253 For the EDA runs we will concentrate on the quasi-coherent mode and the transport which results from it. Specifically, the goals are: 1. Look for q resonant effects: Because the mode is seen in regions with strong pressure gradients and relatively low temperatures, work on this problem has focussed on the family of resistive ballooning modes. One important characteristic of these modes is that they are resonant with rational q surfaces. Observation of this resonance would lend support to the hypothesis linking the QC mode to resistive ballooning. 2. Compare particle (and energy) flux convected by the fluctuation with the local particle and power balance. We have only a small amount of data on this so far. We want to collect more data from the fast scanning probe and compare the fluxes inferred from ionization source as measured by the Lyman-alpha array. 3. Verify the extent and radial structure of the quasi-coherent fluctuation and its relation to density and temperature profiles. Also, we can take this opportunity to get more data on the poloidal mode structure. 4. Use the fast tangential camera to look for the EDA using helium puffs and observing the HeII 4686 line. Plan: Start with shot 1000928010. This shot has a 5.3T breakdown, then ramps the field down to 2.5T to get an ohmic h-mode then ramps the field back up to about 4T to raise q and get into EDA. We will vary the depth of the down ramp and the rate of rise of the up ramp to scan q slowly. We will be looking for reproducible changes in qc mode amplitude, frequency or wave number. The principal diagnostic for these studies will be the PCI. The scanning probe will be used to collect detailed fluctuation data. If clear q dependent effects are seen, we will use the probe to study these in greater detail. To verify the q dependence, we will look for the effect with both upgoing and downgoing Bt ramps. ............................... Alternate run plan: Density limit mechanisms - mp233a We want to collect more data on the changes in turbulence and transport which have been linked to the density limit. In the previous experiments it was observed that the regime of large coherent fluctuations which normally exists in the far scrape-off, moves inward to the separatrix and intrudes into the closed field line regions as the density limit is reached. We will try to insert the probe more deeply into these plasmas at high densities in order to follow the evolution of the profiles and fluctuations. In particular we will try to assess how far into the main plasma this phenomenon reaches. We will also use this opportunity to obtain more data on the changes in transport that accompany the change in fluctuations. The fast camera will be used to look for any visible changes in the edge turbulence - in particular to watch for progressive movement of the turbulent region as the density is raised. 1000620023 would be a good starting point. As before, the approach will be to produce high density ohmic discharges then to ramp down the plasma current to approach the density limit. This gives us density limit disruptions which are reproducible in time which eases the operation of the fast scanning probe. The B$_T$ programming might need to be altered to allow edge profile measurements until the time of the disruptions. Once the shot is set up, few changes are needed | |
| Jun 14 2001 03:28:35:870PM | Martin Greenwald | Run Summary for 1010612 - mp292, mp253 Session Leader - Greenwald Phys Op - Parker Goal: We will concentrate on the quasi-coherent mode and the transport which results from it. Specifically, the goals are: 1. Look for q resonant effects: Because the mode is seen in regions with strong pressure gradients and relatively low temperatures, work on this problem has focussed on the family of resistive ballooning modes. One important characteristic of these modes is that they are resonant with rational q surfaces. Observation of this resonance would lend support to the hypothesis linking the QC mode to resistive ballooning. 2. Compare particle (and energy) flux convected by the fluctuation with the local particle and power balance. We have only a small amount of data on this so far. We want to collect more data from the fast scanning probe and compare the fluxes inferred from ionization source as measured by the Lyman-alpha array. 3. Verify the extent and radial structure of the quasi-coherent fluctuation and its relation to density and temperature profiles. Also, we can take this opportunity to get more data on the poloidal mode structure. 4. Use the fast tangential camera to look for the EDA using helium puffs and observing the HeII 4686 line. Plan: Start with shot 1000928010. This shot has a 5.3T breakdown, then ramps the field down to 2.5T to get an ohmic h-mode then ramps the field back up to about 4T to raise q and get into EDA. We will vary the depth of the down ramp and the rate of rise of the up ramp to scan q slowly. We will be looking for reproducible changes in qc mode amplitude, frequency or wave number. The principal diagnostic for these studies will be the PCI. The scanning probe will be used to collect detailed fluctuation data. If clear q dependent effects are seen, we will use the probe to study these in greater detail. To verify the q dependence, we will look for the effect with both upgoing and downgoing Bt ramps. Results: We had quite a few shots with ohmic EDA. If there was a q resonance effect it must be subtle. There are changes in mode amplitude and frequency observed. The strongest correlation is with sawteeth. There are other excursions which are not correlated with sawteeth and these need to be carefully compared to the q time histories. We got some data from the probes, edge thomson, and from Lyman alpha for the transport studies, these will take more analysis as well. On shot 10, the scanning probes apparently traversed the entire radial extent of the mode - it was 1-2 mm as found earlier. We had less luck with the fast camera. There was insufficient signal from 4686 (HeII). Shot 009 was a particularly nice example of an ELMfree to EDA transition. Shots for further analysis: 1010614003 1010614004 1010614006 1010614008 1010614009 1010614010 1010614014 1010614015 1010614016 1010614017 | |
| Jun 14 2001 09:25:41:593AM | 1010614002 | Martin Greenwald | Very similar to target shot (1000928010) Brief H-mode phase PCI on, but digitization window was incorrect (setting to 1-1.5 sec on next shot) |
| Jun 14 2001 09:41:19:290AM | 1010614003 | Martin Greenwald | Good shot 2 h-modes, first elmfree, second eda qc mode somewhat higher frequency and broader than usual |
| Jun 14 2001 11:05:39:343AM | 1010614004 | Martin Greenwald | similar to shot 2, h-mode very very weak eda mostly propagates in one direction bursts of stronger qc mode at 1.154 and 1.197 sec q95 = 2.64 and 2.75 at those times |
| Jun 14 2001 10:27:47:097AM | 1010614005 | Martin Greenwald | Raised minimum field by about 10% H-mode earlier but no eda |
| Jun 14 2001 11:03:46:450AM | 1010614006 | Martin Greenwald | somewhat better two h-mode periods, first one elmfree second one eda eda disappears for brief periods - q95 = 3.52 - 3.54 q95 = 3.56 q95 = 3.585 - 3.606 is this a q effect or random? we'll repeat this shot and see |
| Jun 14 2001 12:09:42:847PM | 1010614008 | Martin Greenwald | slower Bt ramp after H-mode starts elmfree period, l-mode, then eda |
| Jun 14 2001 12:08:47:610PM | 1010614009 | Martin Greenwald | Good shot makes ELMfree to EDA transition at about 1.3 seconds without dropping back to L-mode |
| Jun 14 2001 12:38:12:873PM | 1010614010 | Martin Greenwald | not quite as good as last shot eda separated by l-mode phase good data from scanning probe |
| Jun 14 2001 12:51:34:333PM | 1010614011 | Martin Greenwald | raised current by about 10% disrupts early elmfree phase only |
| Jun 14 2001 01:04:18:400PM | 1010614012 | Martin Greenwald | Very similar to previous shot |
| Jun 14 2001 01:24:37:087PM | 1010614013 | Martin Greenwald | same as last shot - elmfree only with early disruption |
| Jun 14 2001 02:18:15:873PM | 1010614014 | Martin Greenwald | try to repeat shot 9 got short eda period this time |
| Jun 14 2001 02:27:49:870PM | 1010614015 | Martin Greenwald | Better, got long eda period will put probes in deeper on next shot |
| Jun 14 2001 02:40:35:733PM | 1010614016 | Martin Greenwald | good shot - long eda |
| Jun 14 2001 03:06:56:353PM | 1010614017 | Martin Greenwald | good shot long eda period |
| Physics Operator Comments | |||
| Jun 14 2001 10:14:01:170AM | 1010614001 | Ron Parker | Shot 1 was used as to reset after a computer hangup. |
| Jun 14 2001 10:13:04:277AM | 1010614002 | Ron Parker | Shot 2 was setup to reproduce shot 100098010. The Tf ramps down in this shot from the usual startup value to ~ 70 kA in order to produce an ohmic H-Mode. The shot ran as programmed although it disrupted shortly after the current began to ramp down. |
| Jun 14 2001 10:17:00:237AM | 1010614003 | Ron Parker | Shot 3 was a repeat of shot 2 with PCI timing changed to obtain data during H-Mode. Shot ran as programmed. The disruption occurred somewhat later in the current rampdown. |
| Jun 14 2001 10:19:55:350AM | 1010614004 | Ron Parker | Shot 4 was a repeat of shots 2 and 3 with the exception that a 10% increase in density was programmed. Next shot will be similar, except minimum in TF field will be increased about 10%, to 75 kA. Helium had been inadvertantly pulsed during first 3 shots and will be discontinued for remainder of run. |
| Jun 14 2001 10:25:23:013AM | 1010614005 | Ron Parker | Shot 5 ran as programmed. Minimum TF current was 80 kA. In next shot, this will be increased to 87 kA. |
| Jun 14 2001 10:51:50:210AM | 1010614006 | Ron Parker | Shot 6 ran as programmed. Minimum TF current was 87 kA. Longer rampdown (to 200 kA) before disruption. Next shot: no changes. |
| Jun 14 2001 11:06:16:687AM | 1010614006 | Ron Parker | Slight delay due to computer hangup. |
| Jun 14 2001 11:27:13:890AM | 1010614007 | Ron Parker | Shot 7 was a repeat of shot 6 and ran as programmed. Next shot: slightly less rapid rise in TF after 1.2 s |
| Jun 14 2001 11:51:34:083AM | 1010614008 | Ron Parker | Shot 8 ran well with the TF ramping up at the end more gently. Shot 9 will be a repeat of 8. |
| Jun 14 2001 12:11:19:957PM | 1010614009 | Ron Parker | Shot 9 ran as programmed. Next shot: repeat. |
| Jun 14 2001 12:25:57:933PM | 1010614010 | Ron Parker | Shot 10 was a repeat of shot 9, as programmed. Shot 11 will be programmed with 10% more current -- to 880 kA. |
| Jun 14 2001 12:52:13:397PM | 1010614011 | Ron Parker | Shot 11 disrupted at q~3. In next shot, the target density will be increased 10%. |
| Jun 14 2001 01:06:33:120PM | 1010614012 | Ron Parker | Shot 12 disrupted, again at q ~ 3. Next shot: raise density by 10%. |
| Jun 14 2001 01:31:11:910PM | 1010614013 | Ron Parker | Shots continue to disrupt. Next shot: reload shot 9 |
| Jun 14 2001 01:51:09:050PM | 1010614014 | Ron Parker | Shot 14 ran without disruption as it did in the programmed shot, shot 9. Next shot: repeat |
| Jun 14 2001 02:34:19:333PM | 1010614015 | Ron Parker | Shot 15 repeated as programmed. Next shot: another repeat |
| Jun 14 2001 02:45:21:070PM | 1010614016 | Ron Parker | Shot 16 ran as programmed. Next shot: repeat -- last shot today. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:02:13:667AM | Plasma | Bad | Igor Hung up |
| 2 | 09:16:37:377AM | Plasma | Ok | |
| 3 | 09:31:31:980AM | Plasma | Ok | |
| 4 | 09:55:57:500AM | Plasma | Ok | |
| 5 | 10:18:58:550AM | Plasma | Ok | |
| 6 | 10:38:00:220AM | Plasma | Ok | |
| 7 | 11:08:25:017AM | Plasma | Ok | |
| 8 | 11:34:27:887AM | Plasma | Ok | |
| 9 | 11:57:24:310AM | Plasma | Ok | |
| 10 | 12:17:42:717PM | Plasma | Ok | |
| 11 | 12:40:38:300PM | Plasma | Ok | |
| 12 | 12:59:42:283PM | Plasma | Ok | |
| 13 | 01:21:27:910PM | Plasma | Ok | |
| 14 | 01:44:12:477PM | Plasma | Ok | |
| 15 | 02:12:14:160PM | Plasma | Ok | |
| 16 | 02:34:54:930PM | Plasma | Ok | |
| 17 | 02:57:13:993PM | Plasma | Ok | |