| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Jerry Hughes,Brian Labombard |
| Physics operator(s): | Dmitri Mossessian |
| Engineering operator(s): | Unknown |
| Engineering Operator Run Comment |
| MP #342 and MP #335/Hughes/Labombard/Mossessian |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:33:380PM |
| Author: Jerry Hughes |
| 1030630A Run Summary Physics Operator: D. Mossessian Session Leader: J.W. Hughes This half-day run is in support of MP#342, "Density pedestals in L-mode and H-mode plasmas" Purpose: The objective of the experiment is to examine edge electron density profiles in L-mode plasmas, and to compare with H-mode plasmas having similar values of edge density. Of interest is the behavior of the L-mode density profile as density is varied and the extent to which the target L-mode profiles affect the subsequent H-mode pedestal. SOL profile measurements from Thomson scattering will also be systematically compared with probe scans near the machine midplane. Plan: All shots full length, single lower null discharges at 5.4T. Begin by loading 1030530032, a 600kA shot with target nl04~4e19. 2-3MW flat ICRF pulse should begin at 1.0s in order to trigger H-mode. ASP should be scanned twice prior to RF turn-on, and once afterwards. Supplemental scans of the FSP and ISP may be useful as well. Target density will be scanned upward shot by shot in increments of 2e19. When satisfactory L-mode and H-mode profiles are obtained at each target density, we will proceed to the next higher density. As density becomes higher, we may require additional RF heating (1-2 MW) during the L-mode phase (0.7--1.0s), in order to suppress edge cooling and poloidal detachment. If this doesn't work, we may switch to 800kA discharges in order to complete the high density portion of the scan. Time permitting, shots with target densities in the 4-8e19 range should be repeated at the higher current. Results: After some initial glitches, the run proceeded according to plan and yielded some useful measurements of edge profiles in L-modes produced over a wide range of target densities. Also, good profiles were obtained in H-modes of relatively low pedestal n_e. We came very close to matching L-mode and H-mode pedestal densities at fixed magnetic configuration. Thanks to B. LaBombard, the shots benefited from successful SOL scans of the A-port scanning probe (ASP). SOL data were also obtained on many shots using the F-port (FSP) and inner wall scanning probes (ISP). Thus the measurement goals were fairly well met, and analysis of the measured profiles can proceed. RF power was limited due to a problem with the D-port transmitter and the inability of J-port to perform at high gas pressure. Also, data acquisition problems prevented proper RF tuning between shots and resulted in RF power not being written to the tree prior to shot 11. Despite these limitations, RF heating was sufficient to trigger H-modes at low density and to supress detachment and MARFE phenomena in high-density H-modes. At I_p=600kA, a target density scan from 0.4 to 1.3e20 m^-2 was executed over the course of shots 4 through 14. There were RF-triggered H-modes on shots 5 through 10, with pedestal n_e increasing along with the nl04 target. (X-ray diagnostics did not show evidence of an L-H transition on shots 8-10. B. Granetz therefore insisted that these shots did not go into H-mode, despite evidence from edge TS, H-alpha, etc.) The first upper chamber MARFE of the day occurred during shot 10 (target nl04=1e20). The application of RF power (the exact quantity of power is not in the tree) terminated the MARFE, which was likely a poloidal detachment event, and subsequently triggered a well-behaved H-mode. We subsequently had success suppressing the presumed detachment, though MARFEs continued to plague us on shots 11,14 and 16. Interestingly, during MARFEs, LaBombard noted a marked deficit in density on the inboard SOL, as measured by the ISP, indicating blocked flow of plasma from the outboard side. At the highest target densities, we obtained L-mode pedestal densities close to that of the low-density H-mode on shot 5 (ne_ped~1e20 m^-3), though a perfect match was not obtained. The best success at obtaining high density L-modes was had by ramping the target nl04 from 1.0 to 1.4e20 while ramping RF power from 1.2 to 1.4 MW (Shot 16). On the final shot, 17, I_p was raised to 800 kA, and detachment was avoided, despite faulting on the RF. Overall, it was a productive run. The data collected show promise, in that we should be able to explore trends in the profiles as a function of overall density. Careful analysis of the data will be needed before conclusions are drawn. --Logbook entries: ---------------------------------------------------------------------------- 1030630001 jwhughes SESSION_LEADER Jun 30 2003 10:28:29:343AM . . . . . . . . . . . . . . . . . . . . No plasma ---------------------------------------------------------------------------- 1030630002 jwhughes SESSION_LEADER Jun 30 2003 10:38:58:160AM . . . . . . . . . . . . . . . . . . . . Cycle test, no power. ---------------------------------------------------------------------------- 1030630003 jwhughes SESSION_LEADER Jun 30 2003 11:01:34:876AM . . . . . . . . . . . . . . . . . . . . Plasma, density very low. Getting sporadic edge measurements on the order of 1e19. ---------------------------------------------------------------------------- 1030630004 jwhughes SESSION_LEADER Jun 30 2003 11:12:28:953AM . . . . . . . . . . . . . . . . . . . . No RF shot. Density at the correct level. n_e(95)~2.5e19. n_e(sep)~1.5e19 T_e(95)~100eV. T_e(sep)~50eV ---------------------------------------------------------------------------- 1030630005 jwhughes SESSION_LEADER Jun 30 2003 11:49:55:486AM . . . . . . . . . . . . . . . . . . . . RF went, something between 2 and 3 MW, though there are problems with their CPCI DAQ. Density slightly higher than on last shot. Decent profiles, but could have better edge YAG alignment. L-mode: n_e(95)~2.5e19. n_e(sep)~1.5e19 T_e(95)~100eV. T_e(sep)~50eV H-mode: ne_ped~1e20 Te_ped~400eV ---------------------------------------------------------------------------- 1030630006 jwhughes SESSION_LEADER Jun 30 2003 2:33:48:703PM . . . . . . . . . . . . . . . . . . . . RF went, at some unknown value. Density higher. Still need to get edge alignment a little better L-mode: n_e(95)~4e19. n_e(sep)~2e19 T_e(95)~100eV. T_e(sep)~50eV H-mode: ne_ped~1-1.2e20 Te_ped~300-400eV ---------------------------------------------------------------------------- 1030630007 jwhughes SESSION_LEADER Jun 30 2003 12:06:42:486PM . . . . . . . . . . . . . . . . . . . . nl04 right at 6e19. Got the H-mode at 1s again, though it doesn't look very pretty. There is very good agreement in the density measurements from ASP and TS during the initial H-mode phase. L-mode: n_e(95)~4e19. n_e(sep)~2e19 T_e(sep)~50eV H-mode: ne_ped~1-1.2e20, Te_ped~200-300eV Raise target ne on next shot. ---------------------------------------------------------------------------- 1030630008 jwhughes SESSION_LEADER Jun 30 2003 12:28:37:313PM . . . . . . . . . . . . . . . . . . . . nl04 right at 9e19. Got an EDA-ish H-mode at 1s. L-mode: n_e(95)~6-7e19. n_e(sep)~4-5e19 T_e(sep)~50eV H-mode: ne_ped~1.4-1.5e20 Te_ped~200-250eV ---------------------------------------------------------------------------- 1030630009 jwhughes SESSION_LEADER Jun 30 2003 12:31:12:673PM . . . . . . . . . . . . . . . . . . . . nl04 right at 9e19. Got an H-mode at 1s. RF is still having problems. It can't be tuned properly. Granetz insists there's no H-mode anyway. L-mode: n_e(95)~5-6e19. n_e(sep)~5e19 T_e(sep)~50eV H-mode: ne_ped~1.3-1.4e20 Te_ped~300eV ---------------------------------------------------------------------------- 1030630010 jwhughes SESSION_LEADER Jun 30 2003 12:44:13:063PM . . . . . . . . . . . . . . . . . . . . nl04 programming up to 1e20. Probably too high, leading to detachment. RF seems to make it go away. Got an H-mode at 1.03s. Only good Thomson profiles in L-mode before 0.6s and after 1.3s H-mode: ne_ped~1.5e20 Te_ped~200-300eV ---------------------------------------------------------------------------- 1030630012 jwhughes SESSION_LEADER Jun 30 2003 2:35:03:923PM . . . . . . . . . . . . . . . . . . . . nl04=1e20. Supressed MARFE-ing by increasing RF power to 1 MW early in the discharge. all L-mode, ne_sep~4-5e19, ne_95~6-7e19 Te_sep~40-50eV ---------------------------------------------------------------------------- 1030630013 jwhughes SESSION_LEADER Jun 30 2003 1:33:23:736PM . . . . . . . . . . . . . . . . . . . . nl04=1.15e20. P_RF~1.1MW from 0.7-1.5s. No MARFE. all L-mode, ne_sep~5-6e19, ne_95~7-8e19 Te_sep~30-50eV. We'll push density higher on next shot. Also asking for a little more RF power. ---------------------------------------------------------------------------- 1030630014 jwhughes SESSION_LEADER Jun 30 2003 1:50:05:533PM . . . . . . . . . . . . . . . . . . . . nl04 target was 1.3e20. Huge MARFE that lasts through most of the discharge. Edge TS essentially useless. No substantial RF was coupled, apparently. Dmitri suggests a density ramp-up during the RF phase. ---------------------------------------------------------------------------- 1030630015 jwhughes SESSION_LEADER Jun 30 2003 2:35:55:110PM . . . . . . . . . . . . . . . . . . . . nl04 was ramped from 1-1.4e20. during RF at 1-1.2 MW. MARFE avoided. ne_95 climbed from 7-9e19, while Te_95 decreased. Ask for a little more RF power on next shot. ---------------------------------------------------------------------------- 1030630016 jwhughes SESSION_LEADER Jun 30 2003 2:36:08:423PM . . . . . . . . . . . . . . . . . . . . Programmed same as last shot, but with P_RF ramping from 1.2-1.4MW A good shot, except for the large MARFE from 0.56-.98. Got a decent L-mode measurement after recovery, however. ne_95~8-9e19 Not quite a match with the H-mode pedestal n_e from shot 5, but close. We'll raise the current to 800kA on the next shot. ---------------------------------------------------------------------------- 1030630017 jwhughes SESSION_LEADER Jun 30 2003 2:31:43:063PM . . . . . . . . . . . . . . . . . . . . Good shot. RF tanked early on, but plasma, at an I_p of 800kA, did not detach. L-mode all the way, with ne_95 in the range of .8-1e20. This is the end of my portion of the run. ---------------------------------------------------------------------------- |
| Entered: Jul 7 2004 03:49:33:397PM |
| Author: Brian Labombard |
| Run Summary for 1030630-B, MP#335: "Edge plasma flows in upper versus lower x-point discharges" Session Leader: B. LaBombard Physics Operator: D. Mossessian ________________________________________________________________________________ 1030630-B Run Plan (continuation from 1030619 run) Purpose: The primary purpose of these experiments is to investigate the sensitivity of the magnitude and direction of the parallel plasma flows (routinely observed in the edge plasma) to the magnetic geometry, in particular upper, lower and double-null configurations. Last time we attempted this MP (1030619), we only got 5 data-quality discharges (see run_summary_1030619). This 1/2 day run was aimed at filling in some of the missing data points. Shot Plan: Reload shot 1030619031 All shots are 0.8 MA, 5.3 tesla discharges. Start with SNL 1,2 - NL04 = 0.8, SNL 3,4 - NL04 = 0.6, SNL Switch to SNU 5,6 - NL04 = 0.6, SNU 7,8 - NL04 = 1.2, SNU Switch to SNL 9,10 - NL04 = 1.2, SNL Begin density scan in DN configuration. Shot#11,12,13 - NL04 = 1.0, DN Adjust SSEP for balanced double-null. Tweak equilibrium and FSP/ASP/ISP target. 14,15 - NL04 = 0.8, DN 16,17 - NL04 = 0.6, DN 18,19 - NL04 = 1.2, DN ________________________________________________________________________________ Result: A very productive 1/2 run day, netting 11 more good quality data shots and bringing the total to 16 for this MP - many thanks to Steve Wolfe for finding a way to schedule this make-up session. From these data, a clear picture of the parallel flows in the SOL and their dependence on plasma density is beginning to form: (1) Flows near the inner midplane (as detected by the ISP) care mostly about x-point location. For single null discharges the flow is directed to the active inner divertor: down for SNL discharges and up for SNU discharges. Thus the flow appears to result from plasma streaming along field lines from the low- to high-field SOL. In double null discharges the flow is greatly reduced, consistent with the x-points blocking the communication from low to high-field side. There may be a dependence of the magnitude of the flows on discharge density, favoring stronger flows at high density. This needs to be looked at in detail. (2) Parallel flows at the outer-midplane (as detected by the ASP) do not care about the x-point location. A "co-current" flow is measured regardless of SNL, SNU, or DN configurations. The flow becomes stronger as the plasma density is lowered, as has been seen previously. Thus the explanation of the flow pattern as being a 'toroidal rotation' may be most appropriate here. Unfortunately, the WEST electrode on the FSP probe developed an intermittent open-circuit condition just before the start of the second half of the run (naturally). So there are only a few random measurements of Mach flow from this probe today. Still, these indicate a co-current flow, similar to the ASP measurement. The Chromex spectrometer was looking at toroidal fiber telescope views of the inner and outer SOL, recording He+1 emission resulting from local helium puffs on the inner wall and A/B limiter capillary tubes. The large doppler shifts recorded on the 1030619 run did not seem to be present today. Further analysis is required to understand why. Shots for analysis: 19,20,22,23 - Lower single null, NL04 = .59 <-> .85 24,25,26,27 - Upper single null, NL04 = .53 <-> 1.2 28,30,31 - Double null, NL04 = .6 <-> 1. ________________________________________________________________________________ Detailed shot log: Shot 18 - Fizzle Shot 19 - ASP, FSP, ISP scanning at .8, 1.0, 1.2 s SNL, NL04 = .85 FSP-WEST probe is failing (cable problem, I suspect) ISP data look good. ASP ok Shot 20 - ASP, FSP, ISP scanning at .8, 1.0, 1.2 s SNL, NL04 = .75, rising after NINJA puff ISP data look good. ASP ok Shot 21 - Fizzle Shot 22 - ASP, FSP, ISP scanning at .8, 1.0, 1.2 s SNL, NL04 = .7, rising after NINJA puff ISP data look good. ASP looks good Still problem with FSP-WEST Shot 23 - ASP, FSP, ISP scanning at .8, 1.0, 1.2 s SNL, NL04 = .59, rising after NINJA puff ISP data look good. ASP looks good. Shot 24 - ASP, FSP, ISP scanning at .8, 1.0, 1.2 s SNU, NL04 = .53, rising after NINJA puff ISP sees flow in opposite direction (towards upper divertor) ASP sees same co-current flow as in SNL discharge. Shot 25 - ASP, FSP, ISP scanning at .8, 1.0, 1.2 s SNU, NL04 = .63, rising after NINJA puff again ISP sees flow in opposite direction (towards upper divertor) again ASP sees same co-current flow as in SNL discharge. Shot 26 - ASP, FSP, ISP scanning at .8, 1.0, 1.2 s SNU, NL04 = 1, rising after NINJA puff ISP sees very strong flow towards upper divertor ASP sees no flow. Shot 27 - ASP, FSP, ISP scanning at .8, 1.0, 1.2 s SNU, NL04 = 1.2, rising ~1.4 after NINJA puff ISP sees very strong flow towards upper divertor ASP sees no flow. Shot 28 - ASP, FSP, ISP scanning at .8, 1.0, 1.2 s DN, NL04 = 1. with density/MARFE oscillations to 1.3 ISP sees no flow ASP sees co-current flow. Shot 29 -Fizzle Shot 30 - ASP, FSP, ISP scanning at .8, 1.0, 1.2 s DN, NL04 = .9 ISP sees some flows ASP sees co-current flow. Shot 31 - ASP, FSP, ISP scanning at .8, 1.0, 1.2 s DN, NL04 = .6 ISP -> no flow ASP sees co-current flow. |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:37:18:473PM |
| Author: Dmitri Mossessian |
| Physop summary for 1030630. Run was split between J.Hughes MP#342 "density pedestals" and completion of B. LaBombard's MP#335 "edge plasma flows". SL: Hughes, LaBombard PO: Mossessian Run started at 10:00 Run plans: MP#342 Density pedestals in L-mode and H-mode plasmas Purpose: The objective of the experiment is to examine edge electron density profiles in L-mode plasmas, and to compare with H-mode plasmas having similar values of edge density. Of interest is the behavior of the L-mode density profile as density is varied and the extent to which the target L-mode profiles affect the subsequent H-mode pedestal. SOL profile measurements from Thomson scattering will also be systematically compared with probe scans near the machine midplane. Plan: All shots full length, single lower null discharges at 5.4T. Begin by loading 1030530032, a 600kA shot with target nl04~4e19. 2-3MW flat ICRF pulse should begin at 1.0s in order to trigger H-mode. ASP should be scanned twice prior to RF turn-on, and once afterwards. Supplemental scans of the FSP and ISP may be useful as well. Target density will be scanned upward shot by shot in increments of 2e19. When satisfactory L-mode and H-mode profiles are obtained at each target density, we will proceed to the next higher density. As density becomes higher, we may require additional RF heating (1-2 MW) during the L-mode phase (0.7--1.0s), in order to suppress edge cooling and poloidal detachment. If this doesn't work, we may switch to 800kA discharges in order to complete the high density portion of the scan. Time permitting, shots with target densities in the 4-8e19 range should be repeated at the higher current. MP#335 - Edge plasma flows in upper verus lower x-point discharges Purpose: The primary purpose of these experiments is to investigate the sensitivity of the magnitude and direction of the parallel plasma flows (routinely observed in the edge plasma) to the magnetic geometry, in particular upper, lower and double-null configurations. Shot Plan: Reload shot 1030619031, per Steve Wolfe's advice: "...I recommend loading PCS from 1030619031 and changing the startup in seg 1 to one that works. Segments 2, 3, and 4 in that shot are set up for Lower Null, Upper Null and near-DN with SSEP control, respectively, as called for in Brian's MP. The gaps in seg 2 and 3 were tweaked up to Brian's liking on that day; since we never got to the SSEP control part of the run, segment 3 will need some equilibrium tweaking, but it was taken from a shot that ran ok, and should be close to what he wants." All shots are 0.8 MA, 5.3 tesla discharges. Start with SNL 1,2 - NL04 = 0.8, SNL 3,4 - NL04 = 0.6, SNL Switch to SNU 5,6 - NL04 = 0.6, SNU 7,8 - NL04 = 1.2, SNU Switch to SNL 9,10 - NL04 = 1.2, SNL Begin density scan in DN configuration. Shot#11,12,13 - NL04 = 1.0, DN Adjust SSEP for balanced double-null. Tweak equilibrium and FSP/ASP/ISP target. 14,15 - NL04 = 0.8, DN 16,17 - NL04 = 0.6, DN 18,19 - NL04 = 1.2, DN ________________________________________________________ Summary: Run went OK. Most of the shots have bad current hesitation at the startup. Plasma bounces, probably on the outer wall. Tweaking gas, Bz and RCUR in segmnent 1 did not lead to any improvements (shots 5 through11). Startup sometimes improves by itself, but generally plasma survives the bounce. Even after a fizzle, if nothing changed in the startup the next shot is usually OK. In the second half of the run various configurations were used. Lower adn upper nulls were OK, but when we tried double null first time (shot 28), too much gain in SSEP caused EF2 to oscillate madly. When integral gain on SSEP was turned off a proportional gain was lowered from 5 to 3 the situation improved. On last shot we tried to bring SSEP down from 3 to 2 mm, and the oscillations came back, although not as strong as on shot 28. Total 31 shots 1 dud - no gas, PLC fault 1 test 3 fizzles 26 plasmas Details: ---------------------------------------------------------------------------- 1030630001 mossessian PHYSICS_OPERATOR Jun 30 2003 10:17:19:393AM . . . . . . . . . . . . . . . . . . . . Loaded 1030530032. Wanted to load segment 1 from more recent shot, but realized that startup was much better on 1030530032 than on any of the recent shots. Left segment 1 as is. Dud. No gas - most likely PLC fault. ---------------------------------------------------------------------------- 1030630002 mossessian PHYSICS_OPERATOR Jun 30 2003 10:41:21:360AM . . . . . . . . . . . . . . . . . . . . This will be test cycle to check gas and TF. Looks OK. gas is on. Next shot - plasma attempt ---------------------------------------------------------------------------- 1030630003 mossessian PHYSICS_OPERATOR Jun 30 2003 10:59:09:440AM . . . . . . . . . . . . . . . . . . . . Plasma. Very low density. It turns out that nl04 feedback is OFF on the loaded shot. Next shot - turn nl04 feedback back on. ---------------------------------------------------------------------------- 1030630004 mossessian PHYSICS_OPERATOR Jun 30 2003 11:19:11:970AM . . . . . . . . . . . . . . . . . . . . Plasma. Density is OK. No Rf on this one. Next shot - repeat with RF. ---------------------------------------------------------------------------- 1030630005 mossessian PHYSICS_OPERATOR Jun 30 2003 11:32:10:046AM . . . . . . . . . . . . . . . . . . . . Plasma. H-mode. Startup is bad. Next shot - drop prepuff 26 -> 23 ms to get faster current rise. Target nl up to 6e19 ---------------------------------------------------------------------------- 1030630006 mossessian PHYSICS_OPERATOR Jun 30 2003 11:48:00:173AM . . . . . . . . . . . . . . . . . . . . Plasma. lowering gas did not help the startup. Next shot - Bz up a little: IC_EF4 -1320 -> -1310. No other changes. ---------------------------------------------------------------------------- 1030630007 mossessian PHYSICS_OPERATOR Jun 30 2003 12:02:42:330PM . . . . . . . . . . . . . . . . . . . . Plasma. Bz still too low. Next shot - RCUR down 0.66 -> 0.655 at 0.01 s. Target nl to 8e19 ---------------------------------------------------------------------------- 1030630008 mossessian PHYSICS_OPERATOR Jun 30 2003 12:15:07:673PM . . . . . . . . . . . . . . . . . . . . Plasma. Last change in RCUR seemed to make startup woprse. Next shot - RCUR up 0.655 -> 0.665 at 0.01 s. Ar up to 35 ms. ---------------------------------------------------------------------------- 1030630009 mossessian PHYSICS_OPERATOR Jun 30 2003 12:28:19:690PM . . . . . . . . . . . . . . . . . . . . Plasma. Startup is bad again. Next shot - RCUR up 0.665 -> 0.67 at 0.01 s. Target nl to 1e20 ---------------------------------------------------------------------------- 1030630010 mossessian PHYSICS_OPERATOR Jun 30 2003 12:46:14:970PM . . . . . . . . . . . . . . . . . . . . Plasma. Next shot - RCUR up 0.67 -> 0.65 at 0.01 s. ---------------------------------------------------------------------------- 1030630011 mossessian PHYSICS_OPERATOR Jun 30 2003 12:59:38:050PM . . . . . . . . . . . . . . . . . . . . Plasma. All RCUR changes do not affect the quality of current rise, although plasma position does seem to respond, but in a starnge way. Next shot - RCUR back to 0.66 at 0.01 s. No other changes. ---------------------------------------------------------------------------- 1030630012 mossessian PHYSICS_OPERATOR Jun 30 2003 1:14:39:236PM . . . . . . . . . . . . . . . . . . . . Plasma. Stratup is good. Next shot - target to 1.1e20 ---------------------------------------------------------------------------- 1030630013 mossessian PHYSICS_OPERATOR Jun 30 2003 1:30:23:703PM . . . . . . . . . . . . . . . . . . . . Plasma. Next shot - target to 1.3e20 ---------------------------------------------------------------------------- 1030630014 mossessian PHYSICS_OPERATOR Jun 30 2003 1:48:46:203PM . . . . . . . . . . . . . . . . . . . . Plasma. Plasma detaches early at this density. Next shot - do nl ramp from 1e20 to 1.4e20 from .6 sec when RF starts to 1.5 sec ---------------------------------------------------------------------------- 1030630015 mossessian PHYSICS_OPERATOR Jun 30 2003 2:12:33:860PM . . . . . . . . . . . . . . . . . . . . Plasma. Plasma with good density ramp Next shot - repeat ---------------------------------------------------------------------------- 1030630016 mossessian PHYSICS_OPERATOR Jun 30 2003 2:13:15:440PM . . . . . . . . . . . . . . . . . . . . Plasma. Plasma. Large MARFE Next shot - go to 800 kA current with the same density ramp ---------------------------------------------------------------------------- 1030630017 mossessian PHYSICS_OPERATOR Jun 30 2003 2:46:23:486PM . . . . . . . . . . . . . . . . . . . . Plasma. Nice density ramp with 0.8 MA Next shot - load 1030619031. Load segment 1 from 1030630017 (last shot). ---------------------------------------------------------------------------- 1030630018 mossessian PHYSICS_OPERATOR Jun 30 2003 2:47:30:923PM . . . . . . . . . . . . . . . . . . . . Fizzle. Bounces on the outside. Next shot - Bz up: IC_EF4 -1310 -> -1300 ---------------------------------------------------------------------------- 1030630019 mossessian PHYSICS_OPERATOR Jun 30 2003 3:26:46:330PM . . . . . . . . . . . . . . . . . . . . Plasma. Bounces but survives Next shot - target nl down to 7e19 ---------------------------------------------------------------------------- 1030630020 mossessian PHYSICS_OPERATOR Jun 30 2003 3:27:18:580PM . . . . . . . . . . . . . . . . . . . . Plasma. Next shot - target to 6e19 ---------------------------------------------------------------------------- 1030630021 mossessian PHYSICS_OPERATOR Jun 30 2003 3:40:55:313PM . . . . . . . . . . . . . . . . . . . . Fizzle. Next shot - no startup change. Left gap down 2 mm. 10 msec less of Ar ---------------------------------------------------------------------------- 1030630022 mossessian PHYSICS_OPERATOR Jun 30 2003 3:54:57:890PM . . . . . . . . . . . . . . . . . . . . Plasma. Next shot - target to 5e19 ---------------------------------------------------------------------------- 1030630023 mossessian PHYSICS_OPERATOR Jun 30 2003 3:54:30:330PM . . . . . . . . . . . . . . . . . . . . Plasma. Next shot - switch to Segment 3, Upper null. Target nl to 5e20 ---------------------------------------------------------------------------- 1030630024 mossessian PHYSICS_OPERATOR Jun 30 2003 4:28:29:063PM . . . . . . . . . . . . . . . . . . . . Plasma. Next shot - Target nl to 6e19 ---------------------------------------------------------------------------- 1030630025 mossessian PHYSICS_OPERATOR Jun 30 2003 4:28:17:596PM . . . . . . . . . . . . . . . . . . . . Plasma. Next shot - Target nl to 1e20 ---------------------------------------------------------------------------- 1030630026 mossessian PHYSICS_OPERATOR Jun 30 2003 4:45:17:486PM . . . . . . . . . . . . . . . . . . . . Plasma. Next shot - Target nl to 1.2e20 ---------------------------------------------------------------------------- 1030630027 mossessian PHYSICS_OPERATOR Jun 30 2003 5:02:47:813PM . . . . . . . . . . . . . . . . . . . . Plasma. Next shot - switch to segment 4, double null. Target nl to 1e20 ---------------------------------------------------------------------------- 1030630028 mossessian PHYSICS_OPERATOR Jun 30 2003 5:30:28:970PM . . . . . . . . . . . . . . . . . . . . Plasma. Oscillates between lower and upper null. Next shot - go to nl 8e19. Try again. ---------------------------------------------------------------------------- 1030630029 mossessian PHYSICS_OPERATOR Jun 30 2003 5:42:03:126PM . . . . . . . . . . . . . . . . . . . . Fizzle. The same bounce as before, but this time it kills it. Next shot - no startup changes. Turn off integral gain on SSEP and turn the proportional gain down to 3. ---------------------------------------------------------------------------- 1030630030 mossessian PHYSICS_OPERATOR Jun 30 2003 5:49:49:626PM . . . . . . . . . . . . . . . . . . . . Plasma. Not quite double null, but closer Next shot - target nl to 5e19. SSEP from -3 to -2 mm ---------------------------------------------------------------------------- 1030630031 mossessian PHYSICS_OPERATOR Jun 30 2003 6:10:45:516PM . . . . . . . . . . . . . . . . . . . . Plasma. Some oscillation between x-points as on 28, but weaker. |
| Session Leader Comments | |||
| Jun 30 2003 10:28:29:343AM | 1030630001 | Jerry Hughes | No plasma |
| Jun 30 2003 10:38:58:160AM | 1030630002 | Jerry Hughes | Cycle test, no power. |
| Jun 30 2003 11:01:34:877AM | 1030630003 | Jerry Hughes | Plasma, density very low. Getting sporadic edge measurements on the order of 1e19. |
| Jun 30 2003 11:12:28:953AM | 1030630004 | Jerry Hughes | No RF shot. Density at the correct level. n_e(95)~2.5e19. n_e(sep)~1.5e19 T_e(95)~100eV. T_e(sep)~50eV |
| Jun 30 2003 11:49:55:487AM | 1030630005 | Jerry Hughes | RF went, something between 2 and 3 MW, though there are problems with their CPCI DAQ. Density slightly higher than on last shot. Decent profiles, but could have better edge YAG alignment. L-mode: n_e(95)~2.5e19. n_e(sep)~1.5e19 T_e(95)~100eV. T_e(sep)~50eV H-mode: ne_ped~1e20 Te_ped~400eV |
| Jun 30 2003 02:33:48:703PM | 1030630006 | Jerry Hughes | RF went, at some unknown value. Density higher. Still need to get edge alignment a little better L-mode: n_e(95)~4e19. n_e(sep)~2e19 T_e(95)~100eV. T_e(sep)~50eV H-mode: ne_ped~1-1.2e20 Te_ped~300-400eV |
| Jun 30 2003 12:06:42:487PM | 1030630007 | Jerry Hughes | nl04 right at 6e19. Got the H-mode at 1s again, though it doesn't look very pretty. There is very good agreement in the density measurements from ASP and TS during the initial H-mode phase. L-mode: n_e(95)~4e19. n_e(sep)~2e19 T_e(sep)~50eV H-mode: ne_ped~1-1.2e20, Te_ped~200-300eV Raise target ne on next shot. |
| Jun 30 2003 12:28:37:313PM | 1030630008 | Jerry Hughes | nl04 right at 9e19. Got an EDA-ish H-mode at 1s. L-mode: n_e(95)~6-7e19. n_e(sep)~4-5e19 T_e(sep)~50eV H-mode: ne_ped~1.4-1.5e20 Te_ped~200-250eV |
| Jun 30 2003 12:31:12:673PM | 1030630009 | Jerry Hughes | nl04 right at 9e19. Got an H-mode at 1s. RF is still having problems. It can't be tuned properly. Granetz insists there's no H-mode anyway. L-mode: n_e(95)~5-6e19. n_e(sep)~5e19 T_e(sep)~50eV H-mode: ne_ped~1.3-1.4e20 Te_ped~300eV |
| Jun 30 2003 12:44:13:063PM | 1030630010 | Jerry Hughes | nl04 programming up to 1e20. Probably too high, leading to detachment. RF seems to make it go away. Got an H-mode at 1.03s. Only good Thomson profiles in L-mode before 0.6s and after 1.3s H-mode: ne_ped~1.5e20 Te_ped~200-300eV |
| Jun 30 2003 02:35:03:923PM | 1030630012 | Jerry Hughes | nl04=1e20. Supressed MARFE-ing by increasing RF power to 1 MW early in the discharge. all L-mode, ne_sep~4-5e19, ne_95~6-7e19 Te_sep~40-50eV |
| Jun 30 2003 01:33:23:737PM | 1030630013 | Jerry Hughes | nl04=1.15e20. P_RF~1.1MW from 0.7-1.5s. No MARFE. all L-mode, ne_sep~5-6e19, ne_95~7-8e19 Te_sep~30-50eV. We'll push density higher on next shot. Also asking for a little more RF power. |
| Jun 30 2003 01:50:05:533PM | 1030630014 | Jerry Hughes | nl04 target was 1.3e20. Huge MARFE that lasts through most of the discharge. Edge TS essentially useless. No substantial RF was coupled, apparently. Dmitri suggests a density ramp-up during the RF phase. |
| Jun 30 2003 02:35:55:110PM | 1030630015 | Jerry Hughes | nl04 was ramped from 1-1.4e20. during RF at 1-1.2 MW. MARFE avoided. ne_95 climbed from 7-9e19, while Te_95 decreased. Ask for a little more RF power on next shot. |
| Jun 30 2003 02:36:08:423PM | 1030630016 | Jerry Hughes | Programmed same as last shot, but with P_RF ramping from 1.2-1.4MW A good shot, except for the large MARFE from 0.56-.98. Got a decent L-mode measurement after recovery, however. ne_95~8-9e19 Not quite a match with the H-mode pedestal n_e from shot 5, but close. We'll raise the current to 800kA on the next shot. |
| Jun 30 2003 02:31:43:063PM | 1030630017 | Jerry Hughes | Good shot. RF tanked early on, but plasma, at an I_p of 800kA, did not detach. L-mode all the way, with ne_95 in the range of .8-1e20. This is the end of my portion of the run. |
| Jun 30 2003 02:45:44:987PM | 1030630018 | Brian Labombard | First Shot of MP335 - SOL Flows... Shot 18 - Fizzle, welcome to MP335 |
| Jun 30 2003 03:13:22:093PM | 1030630019 | Brian Labombard | Shot 19 - ASP, FSP, ISP scanning at .8, 1.0, 1.2 s SNL, NL04 = .85 FSP-WEST probe is failing (cable problem, I suspect) ISP data look good. ASP ok |
| Jun 30 2003 03:20:33:220PM | 1030630020 | Brian Labombard | Shot 20 - ASP, FSP, ISP scanning at .8, 1.0, 1.2 s SNL, NL04 = .75, rising after NINJA puff ISP data look good. ASP ok |
| Jun 30 2003 03:29:39:050PM | 1030630021 | Brian Labombard | Shot 21 - ASP, FSP, ISP scanning at .8, 1.0, 1.2 s SNL, NL04 = .7, rising after NINJA puff ISP data look good. ASP looks good Still problem with FSP-WEST |
| Jun 30 2003 04:04:20:813PM | 1030630023 | Brian Labombard | Shot 23 - ASP, FSP, ISP scanning at .8, 1.0, 1.2 s SNL, NL04 = .59, rising after NINJA puff ISP data look good. ASP looks good. Next shot: Upper null |
| Jun 30 2003 04:14:30:800PM | 1030630024 | Brian Labombard | Shot 24 - ASP, FSP, ISP scanning at .8, 1.0, 1.2 s SNU, NL04 = .53, rising after NINJA puff ISP sees flow in opposite direction (towards upper divertor) ASP sees same co-current flow as in SNL discharge. Next shot: raise density |
| Jun 30 2003 04:33:23:127PM | 1030630025 | Brian Labombard | Shot 25 - ASP, FSP, ISP scanning at .8, 1.0, 1.2 s SNU, NL04 = .63, rising after NINJA puff again ISP sees flow in opposite direction (towards upper divertor) again ASP sees same co-current flow as in SNL discharge. Next shot: NL04=1 |
| Jun 30 2003 04:45:12:563PM | 1030630026 | Brian Labombard | Shot 26 - ASP, FSP, ISP scanning at .8, 1.0, 1.2 s SNU, NL04 = 1, rising after NINJA puff ISP sees very strong flow towards upper divertor ASP sees no flow. Next shot: NL04=1.2 |
| Jun 30 2003 05:03:56:643PM | 1030630027 | Brian Labombard | Shot 27 - ASP, FSP, ISP scanning at .8, 1.0, 1.2 s SNU, NL04 = 1.2, rising ~1.4 after NINJA puff ISP sees very strong flow towards upper divertor ASP sees no flow. Next shot: Go to Double Null, NL04 ~ 1 |
| Jun 30 2003 05:25:00:783PM | 1030630028 | Brian Labombard | Shot 28 - ASP, FSP, ISP scanning at .8, 1.0, 1.2 s DN, NL04 = 1. with density/MARFE oscillations to 1.3 ISP sees no flow ASP sees co-current flow. Next shot: Go to NL04 ~ 0.8 |
| Jun 30 2003 05:54:49:690PM | 1030630030 | Brian Labombard | Shot 30 - ASP, FSP, ISP scanning at .8, 1.0, 1.2 s DN, NL04 = .9 ISP sees some flows ASP sees co-current flow. Next shot: Go to NL04 ~ 0.6 |
| Jun 30 2003 06:05:20:347PM | 1030630031 | Brian Labombard | Shot 31 - ASP, FSP, ISP scanning at .8, 1.0, 1.2 s DN, NL04 = .6 ISP -> no flow ASP sees co-current flow. |
| Physics Operator Comments | |||
| Jun 30 2003 09:57:23:330AM | Dmitri Mossessian | Run to be split between J.Hughes MP#342 "density pedestals" and completion of B. LaBombard's MP#335 "edge plasma flows". SL: Hughes, LaBombard PO: Mossessian Run starts at 10:00 ECDC in deuterium over the weekend Power Systems as on 1030620001 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 10 psi D2 Hybrid DISABLED (PG2) (for ECDC) fill C-side with 30 psi D2 Hybrid enabled (PG3) Enable the following gate valves, assuming no vacuum problems: ECE, DNB, VUV Run plans: MP#342 Density pedestals in L-mode and H-mode plasmas Purpose: The objective of the experiment is to examine edge electron density profiles in L-mode plasmas, and to compare with H-mode plasmas having similar values of edge density. Of interest is the behavior of the L-mode density profile as density is varied and the extent to which the target L-mode profiles affect the subsequent H-mode pedestal. SOL profile measurements from Thomson scattering will also be systematically compared with probe scans near the machine midplane. Plan: All shots full length, single lower null discharges at 5.4T. Begin by loading 1030530032, a 600kA shot with target nl04~4e19. 2-3MW flat ICRF pulse should begin at 1.0s in order to trigger H-mode. ASP should be scanned twice prior to RF turn-on, and once afterwards. Supplemental scans of the FSP and ISP may be useful as well. Target density will be scanned upward shot by shot in increments of 2e19. When satisfactory L-mode and H-mode profiles are obtained at each target density, we will proceed to the next higher density. As density becomes higher, we may require additional RF heating (1-2 MW) during the L-mode phase (0.7--1.0s), in order to suppress edge cooling and poloidal detachment. If this doesn't work, we may switch to 800kA discharges in order to complete the high density portion of the scan. Time permitting, shots with target densities in the 4-8e19 range should be repeated at the higher current. MP#335 - Edge plasma flows in upper verus lower x-point discharges Purpose: The primary purpose of these experiments is to investigate the sensitivity of the magnitude and direction of the parallel plasma flows (routinely observed in the edge plasma) to the magnetic geometry, in particular upper, lower and double-null configurations. Shot Plan: Reload shot 1030619031, per Steve Wolfe's advice: "...I recommend loading PCS from 1030619031 and changing the startup in seg 1 to one that works. Segments 2, 3, and 4 in that shot are set up for Lower Null, Upper Null and near-DN with SSEP control, respectively, as called for in Brian's MP. The gaps in seg 2 and 3 were tweaked up to Brian's liking on that day; since we never got to the SSEP control part of the run, segment 3 will need some equilibrium tweaking, but it was taken from a shot that ran ok, and should be close to what he wants." All shots are 0.8 MA, 5.3 tesla discharges. Start with SNL 1,2 - NL04 = 0.8, SNL 3,4 - NL04 = 0.6, SNL Switch to SNU 5,6 - NL04 = 0.6, SNU 7,8 - NL04 = 1.2, SNU Switch to SNL 9,10 - NL04 = 1.2, SNL Begin density scan in DN configuration. Shot#11,12,13 - NL04 = 1.0, DN Adjust SSEP for balanced double-null. Tweak equilibrium and FSP/ASP/ISP target. 14,15 - NL04 = 0.8, DN 16,17 - NL04 = 0.6, DN 18,19 - NL04 = 1.2, DN | |
| Jun 30 2003 10:17:19:393AM | 1030630001 | Dmitri Mossessian | Loaded 1030530032. Wanted to load segment 1 from more recent shot, but realized that startup was much better on 1030530032 than on any of the recent shots. Left segment 1 as is. Dud. No gas - most likely PLC fault. |
| Jun 30 2003 10:41:21:360AM | 1030630002 | Dmitri Mossessian | This will be test cycle to check gas and TF. Looks OK. gas is on. Next shot - plasma attempt |
| Jun 30 2003 10:59:09:440AM | 1030630003 | Dmitri Mossessian | Plasma. Very low density. It turns out that nl04 feedback is OFF on the loaded shot. Next shot - turn nl04 feedback back on. |
| Jun 30 2003 11:19:11:970AM | 1030630004 | Dmitri Mossessian | Plasma. Density is OK. No Rf on this one. Next shot - repeat with RF. |
| Jun 30 2003 11:32:10:047AM | 1030630005 | Dmitri Mossessian | Plasma. H-mode. Startup is bad. Next shot - drop prepuff 26 -> 23 ms to get faster current rise. Target nl up to 6e19 |
| Jun 30 2003 11:48:00:173AM | 1030630006 | Dmitri Mossessian | Plasma. lowering gas did not help the startup. Next shot - Bz up a little: IC_EF4 -1320 -> -1310. No other changes. |
| Jun 30 2003 12:02:42:330PM | 1030630007 | Dmitri Mossessian | Plasma. Bz still too low. Next shot - RCUR down 0.66 -> 0.655 at 0.01 s. Target nl to 8e19 |
| Jun 30 2003 12:15:07:673PM | 1030630008 | Dmitri Mossessian | Plasma. Last change in RCUR seemed to make startup woprse. Next shot - RCUR up 0.655 -> 0.665 at 0.01 s. Ar up to 35 ms. |
| Jun 30 2003 12:28:19:690PM | 1030630009 | Dmitri Mossessian | Plasma. Startup is bad again. Next shot - RCUR up 0.665 -> 0.67 at 0.01 s. Target nl to 1e20 |
| Jun 30 2003 12:46:14:970PM | 1030630010 | Dmitri Mossessian | Plasma. Next shot - RCUR up 0.67 -> 0.65 at 0.01 s. |
| Jun 30 2003 12:59:38:050PM | 1030630011 | Dmitri Mossessian | Plasma. All RCUR changes do not affect the quality of current rise, although plasma position does seem to respond, but in a starnge way. Next shot - RCUR back to 0.66 at 0.01 s. No other changes. |
| Jun 30 2003 01:14:39:237PM | 1030630012 | Dmitri Mossessian | Plasma. Stratup is good. Next shot - target to 1.1e20 |
| Jun 30 2003 01:30:23:703PM | 1030630013 | Dmitri Mossessian | Plasma. Next shot - target to 1.3e20 |
| Jun 30 2003 01:48:46:203PM | 1030630014 | Dmitri Mossessian | Plasma. Plasma detaches early at this density. Next shot - do nl ramp from 1e20 to 1.4e20 from .6 sec when RF starts to 1.5 sec |
| Jun 30 2003 02:12:33:860PM | 1030630015 | Dmitri Mossessian | Plasma. Plasma with good density ramp Next shot - repeat |
| Jun 30 2003 02:13:15:440PM | 1030630016 | Dmitri Mossessian | Plasma. Plasma. Large MARFE Next shot - go to 800 kA current with the same density ramp |
| Jun 30 2003 02:46:23:487PM | 1030630017 | Dmitri Mossessian | Plasma. Nice density ramp with 0.8 MA Next shot - load 1030619031. Load segment 1 from 1030630017 (last shot). |
| Jun 30 2003 02:47:30:923PM | 1030630018 | Dmitri Mossessian | Fizzle. Bounces on the outside. Next shot - Bz up: IC_EF4 -1310 -> -1300 |
| Jun 30 2003 03:26:46:330PM | 1030630019 | Dmitri Mossessian | Plasma. Bounces but survives Next shot - target nl down to 7e19 |
| Jun 30 2003 03:27:18:580PM | 1030630020 | Dmitri Mossessian | Plasma. Next shot - target to 6e19 |
| Jun 30 2003 03:40:55:313PM | 1030630021 | Dmitri Mossessian | Fizzle. Next shot - no startup change. Left gap down 2 mm. 10 msec less of Ar |
| Jun 30 2003 03:54:57:890PM | 1030630022 | Dmitri Mossessian | Plasma. Next shot - target to 5e19 |
| Jun 30 2003 03:54:30:330PM | 1030630023 | Dmitri Mossessian | Plasma. Next shot - switch to Segment 3, Upper null. Target nl to 5e20 |
| Jun 30 2003 04:28:29:063PM | 1030630024 | Dmitri Mossessian | Plasma. Next shot - Target nl to 6e19 |
| Jun 30 2003 04:28:17:597PM | 1030630025 | Dmitri Mossessian | Plasma. Next shot - Target nl to 1e20 |
| Jun 30 2003 04:45:17:487PM | 1030630026 | Dmitri Mossessian | Plasma. Next shot - Target nl to 1.2e20 |
| Jun 30 2003 05:02:47:813PM | 1030630027 | Dmitri Mossessian | Plasma. Next shot - switch to segment 4, double null. Target nl to 1e20 |
| Jun 30 2003 05:30:28:970PM | 1030630028 | Dmitri Mossessian | Plasma. Oscillates between lower and upper null. Next shot - go to nl 8e19. Try again. |
| Jun 30 2003 05:42:03:127PM | 1030630029 | Dmitri Mossessian | Fizzle. The same bounce as before, but this time it kills it. Next shot - no startup changes. Turn off integral gain on SSEP and turn the proportional gain down to 3. |
| Jun 30 2003 05:49:49:627PM | 1030630030 | Dmitri Mossessian | Plasma. Not quite double null, but closer Next shot - target nl to 5e19. SSEP from -3 to -2 mm |
| Jun 30 2003 06:10:45:517PM | 1030630031 | Dmitri Mossessian | Plasma. Some oscillation between x-points as on 28, but weaker. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 10:13:24:767AM | Plasma | Bad | NO Gas, Bad TF Rogowski |
| 2 | 10:36:01:313AM | Test | Ok | camad test |
| 3 | 10:45:19:907AM | Plasma | Ok | |
| 4 | 11:01:43:377AM | Plasma | Ok | |
| 5 | 11:19:33:517AM | Plasma | Ok | |
| 6 | 11:36:26:690AM | Plasma | Ok | |
| 7 | 11:52:17:487AM | Plasma | Ok | |
| 8 | 12:05:34:593PM | Plasma | Ok | |
| 9 | 12:18:48:440PM | Plasma | Ok | |
| 10 | 12:34:17:360PM | Plasma | Ok | |
| 11 | 12:52:16:313PM | Plasma | Ok | |
| 12 | 01:05:49:843PM | Plasma | Ok | |
| 13 | 01:23:31:440PM | Plasma | Ok | |
| 14 | 01:39:22:300PM | Plasma | Ok | |
| 15 | 01:52:44:813PM | Plasma | Ok | |
| 16 | 02:06:56:487PM | Plasma | Ok | |
| 17 | 02:24:52:050PM | Plasma | Ok | |
| 18 | 02:39:30:110PM | Plasma | Ok | |
| 19 | 02:52:35:093PM | Plasma | Ok | |
| 20 | 03:07:35:470PM | Plasma | Ok | |
| 21 | 03:20:59:377PM | Plasma | Ok | |
| 22 | 03:34:17:377PM | Plasma | Ok | |
| 23 | 03:47:20:610PM | Plasma | Ok | |
| 24 | 04:02:04:250PM | Plasma | Ok | |
| 25 | 04:21:57:750PM | Plasma | Ok | |
| 26 | 04:37:02:173PM | Plasma | Ok | |
| 27 | 04:56:09:550PM | Plasma | Ok | |
| 28 | 05:09:21:300PM | Plasma | Ok | |
| 29 | 05:27:14:517PM | Plasma | Ok | |
| 30 | 05:43:03:737PM | Plasma | Ok | |
| 31 | 05:56:00:517PM | Plasma | Ok | |