| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Brian Labombard,Amanda Hubbard |
| Physics operator(s): | Dmitri Mossessian |
| Engineering operator(s): | Unknown |
| Engineering Operator Run Comment |
| 1/2 day of MP #335-Edge plasma flows in upper vs lower x-point discharge |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:34:913PM |
| Author: Brian Labombard |
| Run Summary for 1031124, MP#335: "Edge plasma flows in upper versus lower x-point discharges" Physics Operator: D. Mossessian Session Leader: B. LaBombard ________________________________________________________________________________ 1031124 Run Plan MP#335 - Edge plasma flows in upper versus 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. Today's Run: This run is a continuation from 1031118. Today we are looking to start taking data from double-null discharges. Also, we would like to revisit high-density lower single null plasmas to see if the difference in upper-null and lower-null toroidal rotation tends to zero. We also want to try a slow SSEP sweep. For all non-SSEP sweep shots, we want left gap to be 13 mm and right gap to be 15 mm. This will allow the ISP to reach the separatrix and provide a reasonable SOL width at the outer midplane to look at flows. NINJA gas setup is 300 torr helium. All shots are nominally 0.8 MA, 5.3 tesla discharges Optional RF conditioning after 1.2 s Reload from shot#1031118018 with segment 4 turned on Set density program (in segment 4!) to NL04 = 0.8 This is a double-null plasma with SSEP feedback control. NOTE on shot#1031118018: Segment 2 - single null lower Segment 3 - single null upper Segment 4 - double null Shot Plan: Shot#1-4 (DN) Turn on segment 4 Program NL04 = 0.8x10^20 m^-2 Can proportional gain on SSEP be decreased to remove x-pt oscillations? Increase right gap by 3 mm (to 15 mm). Decrease left gap by 3 mm (to 13 mm). Check probe targeting. 5,6 - NL04 = 0.6, DN 7,8 - NL04 = 1.0, DN 9,10 - NL04 = 1.2, DN SSEP Scan Program slow SSEP sweep from lower to upper null ( -2 < SSEP < +2 cm) 11,12 - NL04 = 0.8 Revisit SNL reload Shot# 1031118016 (segment 2 active) 13, 14 - NL04 = 1.2 15, 16 - NL04 = 1.4 (if needed, to detach inner wall SOL) ________________________________________________________________________________ Result: We got 12 data-quality shots today which was enough to declare the MP complete. The effort focussed on getting good data from three scanning probes (ASP,FSP,ISP) up to the separatrix in double-null discharges as well as good data from HIREX (core rotation) and Chromex (He+1 doppler in inner/out SOL) diagnostics. It took a few shots to set up the gaps and probe targeting for the double-null discharge but once this was done, the data flowed quickly. We did a density scan followed by a repeat of a previous lower single-null discharge (1031118018) in order to verify that the spectrometers (HIREX, CHROMEX) would produce the same doppler shift as seen previously. The HIREX-inferred rotation did repeat. The ISP (inner-wall probe) recorded strong flows again today, except during times when the upper/lower null appeared to be very well balanced. In fact, the inner-wall flow appears to be a more sensitive indication of magnetic balance than the SSEP signal. It is interesting to note that the HIREX-inferred flows during double null seemed to track the upper-single null trend versus density seen previously. Perhaps our 'double-null' discharges were favoring upper single-null today. Further analysis of the ISP data should tell us if there was a preference for upper null (flows towards top). During shots 19 and 20, SSEP was scanned in time (0.75 to 1.15s) to change from lower to upper single null. Shot 20 (-4 to +4 mm SSEP ramp) showed the clearest transition. Flows from ISP clearly changed as expected. HIREX and CHROMEX also showed a change in the doppler shifts. It will be interesting to compare the CHROMEX data with the scanning probe data, since these diagnostics should be measuring the same bulk plasma flows. Shot Summary: [values in () are probe rest positions for future reference] 1 - no power data system test 2 - dud 3 - DN, NL04=0.84, no probe scanning 4 - dud 5 - DN, NL04=0.8, ASP (+10), FSP(+10), ISP - good data, probes not at SEP 6 - dud 7 - DN, NL04=0.8, ASP (+11), FSP(+11), ISP - probes not at SEP, no ISP data on 2nd and 3rd scans 8 - DN, NL04=0.8, ASP (+13), FSP(+12), ISP - good data, ASP not at SEP 9 - DN, NL04=0.88 - 0.92, ASP (+15), FSP(+12), ISP - excellent data 10- DN, NL04=0.62+, ASP (+15), FSP(+12), ISP - good data. Looks like ISP sees zero flow at 0.95s on this shot. 11- DN, NL04=0.54 - 0.61, ASP (+15), FSP(+12), ISP - good data 12- no TF supply 13- DN, NL04=0.7- 0.74, ASP (+15), FSP(+12), ISP - good data 14- fizzle 15- DN, NL04=1.0, ASP (+15.5), FSP(+12), ISP - good data 16- fizzle 17- DN, NL04=1.2, ASP (+16), FSP(+12), ISP - good data 18 - fizzle 19 - SSEP Sweep (-2 to +2 mm), NL04=0.8-0.9, ASP (+16), FSP(+12), ISP - good data 20 - SSEP Sweep (-4 to +4 mm), NL04=0.7-0.8, ASP (+16), FSP(+12), ISP - good data ISP sees flow direction change SNL->SNU. Also HIREX sees rotation change. 21 - fizzle 22 - SNL, NL04=0.75, ASP(+9), FSP(-4), ISP - excellent data End of MP#335 "Edge plasma flows in upper versus lower x-point discharges" |
| Entered: Jul 7 2004 03:49:34:930PM |
| Author: Amanda Hubbard |
Session leader summary for 1031124 B (afternoon) MP 363: Investigation of L-H Threshold conditions in LSN, DN, USN and limiter confugurations. Session Leader: Amanda Hubbard Physics Operator: Dmitri Mossessian. This run got started at about 2pm, following successful completion of MP 335. The afternoon was primarily devoted to Step 1 of the MP, Shape development of an upper null discharge optimized for good Edge Thomson Scattering coverage. We started on Shot 24, with a shape loaded from Brian's run. The primary shape changes required were to move the x-pt position further in. On shots 25 and 27 it was apparently too far in, as we had impurity influxes and signs of heating up the inner/upper plates. Shots 28 and 29 had the best shape. Parameters were: 5.4 T, 780 kA, delta_u=0.65, delta_l=0.35, kappa=1.67. Target density was 8x10^19 m-2, though there was a strong density increase during the RF pulse; presumably due to outgassing. Ninja was puffing which may or may not have played a role. RF worked well, with up to 5.3 MW on Shot 28; a brief H-mode at 4.2 MW gave an indication of the high power threshold. Shot 29 had flat 4.4 MW, and a longer H-mode. Ne and Prad were rising during H-mode. Shot 1031124029 will be used as the USN target shape for future runs. For the remaining shots, we went to LSN and tried to form the 'inverse' of the USN shape, by moving the lower x-point in. Shot 31 had delta_l=0.75 (too high) and signs of vessel heating. Much lower power (and edge T) thresholds; Pthresh < 1 MW. Shot 33, the last of the day, had delta_l=0.65, as requested, though still some signs of excessive interaction. This shot used as a starting point for 1031125. All in all a successful start to MP 363; completed step 1 and started step 2. Overnight ECDC carried out after run to clean up vessel; proved useful to do shape development on a separate day. |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:37:19:800PM |
| Author: Dmitri Mossessian |
| Physop summary for 1031124: __________________________________________ Engineering Setup and Run Plan for 11/24/03 1/2 day of MP #335-Edge plasma flows in upper vs lower x-point discharges Session Leader: LaBombard 1/2 day MP #363 LH Threshold Session Leader: Hubbard Physics operator: Mossessian ECDC in D2 at 2e-4 Torr, stopping by 07:00. Bake at 60 C as well. Run begins at 09:00 and ends at 17:00. Power systems the same as on 1031114027 A-coils should be hooked up as on 1031114027 (+Dtop -Dbot -Jtop +Jbot). Enable the power supply. Gas setup: fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar Hybrid enabled (PG1) leave B-side upper as is Hybrid DISABLED (PG2) fill C-side with 30 psi D2 Hybrid enabled (PG3) Enable the following gate valves, assuming no vacuum problems: ECE, VUV, DNB RF Setup:Transmitters 1,2,3 & 4 in Run On by 08:00. _________________________________________________________ Summary: Reasonable succesful run. The first part of the run plan (MP 335 - Edge flows) was finished. The second part (MP 363 - LH threshold) was started. There were a few data system problems and some CAMAC problems. data system test on shot 1 went OK, but computers were frozen several times after that during INIT phase. Most of the time Josh and Tom were able to fix the problem right away so that the system went into the plasma shot, but on shot 23 we had to have no power shot. At the beginning of the day we had several duds ( 2, 4, and 6). After that it looked like we went into the alternating fizzle/plasma sequence. However, most of the times when we waited for about 15 minutes after a plasma shot the next shot was also plasma. I tried to avoid fizzles by reducing the amount of prepuff to 15 msec, but it did not help. In fizzles the fields, gas pressure (when ratiomatic worked) and positions were exactly the same as in plasma shots. It seems that the fizzles were caused by excessive amount of carbon appearing in the machine after each plasma shot. On shot 12 TF power supply was not reset properly, which happens from time to time according to the machine operator. We ran both double null and upper null discharges with no trouble at all. The upper null shots disrupted when outer upper strike point was moved onto the upper divertor nose. We were easily able to adjust the position of upper x-point to achieve the required triangularity with the desired position of the strike point and avoid disruptions. The SSEP scan we tried to go from lower null to upper null through double null configuration in one discharge worked fine. Total - 33 shots Duds - 3 Tests - 1 No power shot - 1 No TF shot - 1 Fizzles - 7 Plasmas - 20 Details: ---------------------------------------------------------------------------- 1031124001 mossessian PHYSICS_OPERATOR Nov 24 2003 9:12:09:466AM Reload from shot#1031118018 Turn on segment 4 Set density program (in segment 4!) to NL04 = 0.8 This is a double-null plasma with SSEP feedback control. NOTE on shot#1031118018: Segment 2 - single null lower Segment 3 - single null upper Segment 4 - double null Shot Plan: Shot#1-4 (DN) Turn on segment 4 Program NL04 = 0.8x1020 m^-2 Can proportional gain on SSEP be decreased to remove x-pt oscillations? Increase right gap by 3 mm (to 15 mm). Decrease left gap by 3 mm (to 13 mm). Check probe targeting. 5,6 - NL04 = 0.6, DN 7,8 - NL04 = 1.0, DN 9,10 - NL04 = 1.2, DN SSEP Scan Program slow SSEP sweep from lower to upper null ( -2 < SSEP < +2 cm) 11,12 - NL04 = 0.8 Revisit SNL reload Shot# 1031118016 (segment 2 active) 13, 14 - NL04 = 1.2 15, 16 - NL04 = 1.4 (if needed, to detach inner-wall SOL) . . . . . . . . . . . . . . . . . . . . Data systems test. Seems to have a CAMAC problem with gas sygnals - no ratiomatic sysnal. Go for a plasma shot as is. ---------------------------------------------------------------------------- 1031124002 mossessian PHYSICS_OPERATOR Nov 24 2003 9:24:08:716AM . . . . . . . . . . . . . . . . . . . . Dud. Ratiomatic is back and showing a lot of pressure (~0.085) Wolfe thinks Bz is too low Next shot: Drop prepuff from 20 to 18 ms. Add 10 A to EF4 current to raise Bz a little. ---------------------------------------------------------------------------- 1031124003 mossessian PHYSICS_OPERATOR Nov 24 2003 9:42:59:840AM . . . . . . . . . . . . . . . . . . . . Plasma. Nice startup. Good double null. Next shot: Decrease left gap by 2 mm from .7 to 1.5, drop right gap 2 mm at 1.5 sec, leaving .7 sec value the same To do that - CLEARIN down 2 mm between 0.7 and 1.5 sec. RCUR down 1 mm at 0.75 sec ---------------------------------------------------------------------------- 1031124004 mossessian PHYSICS_OPERATOR Nov 24 2003 10:00:00:250AM . . . . . . . . . . . . . . . . . . . . Dud. Pressures and fields are no different from shot 3. Next shot - no change ---------------------------------------------------------------------------- 1031124005 mossessian PHYSICS_OPERATOR Nov 24 2003 10:21:55:873AM . . . . . . . . . . . . . . . . . . . . Plasma. Lower x-point is not very steady. RX_L ramps down 1 cm from .7 to 1.5 sec. Right gap is a bit too large according to Brian Next shot: RCUR down 1 mm at 0.75 and 1.5 mm at 1.5 sec RXL up 1 cm at 1.5 sec SSEP down -0.002 -> -0.003 Ar pulse 30 -> 50 msec ---------------------------------------------------------------------------- 1031124006 mossessian PHYSICS_OPERATOR Nov 24 2003 10:23:53:856AM . . . . . . . . . . . . . . . . . . . . Dud. Next shot - Jim will increase sparker voltage. No PCS changes. ---------------------------------------------------------------------------- 1031124007 mossessian PHYSICS_OPERATOR Nov 24 2003 10:50:47:856AM . . . . . . . . . . . . . . . . . . . . Plasma. As close to double null as we can get. Left gap is 1 mm smaller than needed. Next shot: CLEARIN up 1 mm A coil voltage down to 2500 ---------------------------------------------------------------------------- 1031124008 mossessian PHYSICS_OPERATOR Nov 24 2003 11:03:22:530AM . . . . . . . . . . . . . . . . . . . . Plasma. Disrupts at 1.57 for no apparent reason. Next shot: no PCS changes ---------------------------------------------------------------------------- 1031124009 mossessian PHYSICS_OPERATOR Nov 24 2003 11:10:37:670AM . . . . . . . . . . . . . . . . . . . . Plasma. Disrupts at 1.57 again. Next shot: nl down to .6e20. SSEP down to -0.001 at 1.7 sec ---------------------------------------------------------------------------- 1031124010 mossessian PHYSICS_OPERATOR Nov 24 2003 11:27:11:123AM . . . . . . . . . . . . . . . . . . . . Plasma. Next shot: nl down to 0.5e20 ---------------------------------------------------------------------------- 1031124011 mossessian PHYSICS_OPERATOR Nov 24 2003 11:41:55:216AM . . . . . . . . . . . . . . . . . . . . Plasma. Next shot: nl up to .7e20 ---------------------------------------------------------------------------- 1031124012 mossessian PHYSICS_OPERATOR Nov 24 2003 11:53:45:230AM . . . . . . . . . . . . . . . . . . . . No TF. Supply was not reset properly. Next shot: no change ---------------------------------------------------------------------------- 1031124013 mossessian PHYSICS_OPERATOR Nov 24 2003 12:09:30:043PM . . . . . . . . . . . . . . . . . . . . Plasma. Disrupted at 1.57 sec. It seems that density is too high when current starts ramping down. Next shot: End RF a little earlier to get out of H-mode when Ip starts going down. nl up to 1e20 ---------------------------------------------------------------------------- 1031124014 mossessian PHYSICS_OPERATOR Nov 24 2003 12:25:00:936PM . . . . . . . . . . . . . . . . . . . . Fizzle. Probably too much gas after disruption leads to slow current rise. We can't check it because the ratiomatic is dead. Next shot: no change ---------------------------------------------------------------------------- 1031124015 mossessian PHYSICS_OPERATOR Nov 24 2003 12:34:34:030PM . . . . . . . . . . . . . . . . . . . . Plasma. Next shot: Tweaked TF to get 5.4 T (at Amanda's request). nl up to 1.2e20 CLEARIN down 1 mm ---------------------------------------------------------------------------- 1031124016 mossessian PHYSICS_OPERATOR Nov 24 2003 12:43:01:793PM . . . . . . . . . . . . . . . . . . . . Fizzle. Fields, positions and current rise rate are exactly the same as on 15. Next shot: no change ---------------------------------------------------------------------------- 1031124017 mossessian PHYSICS_OPERATOR Nov 24 2003 1:09:50:216PM . . . . . . . . . . . . . . . . . . . . Plasma. Next shot: Do SSEP scan going from LN at 0.75 sec to UN at 1.15 sec. Set SSEP to -.005 at .75, -.003 at .95 and -.001 at 1.15 sec Increase gaps by 1 mm - CLEARIN up 1 mm nl back to 0.8e20 ---------------------------------------------------------------------------- 1031124018 mossessian PHYSICS_OPERATOR Nov 24 2003 1:16:06:640PM . . . . . . . . . . . . . . . . . . . . Fizzle. Everything seems to be the same as on a good shot, except for C radiation level. It is possible that after every good shot we have too much C in the machine which kills next plasma before it is born. We will try to drop the prepuff after next plasma to solve the problem. Next shot: no change ---------------------------------------------------------------------------- 1031124019 mossessian PHYSICS_OPERATOR Nov 24 2003 1:33:22:436PM . . . . . . . . . . . . . . . . . . . . Plasma. Nice SSEP scan. Next shot: Drop prepuff in segment 1 from 18 to 16 msec Try wider scan of SSEP from -.007 at .75 to +0.001 at 1.15 sec nl down to 0.7e20 ---------------------------------------------------------------------------- 1031124020 mossessian PHYSICS_OPERATOR Nov 24 2003 1:45:33:106PM . . . . . . . . . . . . . . . . . . . . Plasma. SSEP scan works. Next shot: Lower null. Turn segment 2 on. Change nl target to 7.5e19 ---------------------------------------------------------------------------- 1031124021 mossessian PHYSICS_OPERATOR Nov 24 2003 1:50:03:543PM . . . . . . . . . . . . . . . . . . . . Fizzle. Too much carbon again ? Next shot: no change ---------------------------------------------------------------------------- 1031124022 mossessian PHYSICS_OPERATOR Nov 24 2003 2:09:38:280PM . . . . . . . . . . . . . . . . . . . . Plasma. Next shot: Switching to MP#363 LH Threshold Switch to segment 3 of the same shot - upper null configuration. Set nl to 8e19 Drop prepuff to 15 msec Run Plan for MP 363 1) Establish the optimum shape for USN plasmas which gives the best pedestal region coverage and signal/noise on edge TS. Start from shots on in Brian's MP. Adjust shape as indicated by Jerry; cell access to adjust fibre positions if needed. This will determine kappa and delta for the other configurations. 2) Switch to LSN. 800 kA, ~ 5.4 T. 3-4 shots. a) Power ramp up to ~ 3 MW, to determine L-H threshold. b) Discharge with fixed power just below threshold, for 100-200 ms, followed by high power phase (4-5 MW). Repeat as needed for probe, HIREX. 3) Switch to DN . 5-6 discharges. a) 2 Discharges at power which gave L-H threshold in LSN (eg. 1 MW). Document ETS profiles, flows, rotation. b) Power ramp to maximum available (5 MW>) to determine the new L-H threshold. c) As above, make discharges with power just below L-H transition for ~ 200 ms, followed by higher power to get H-mode phase. ---------------------------------------------------------------------------- 1031124023 mossessian PHYSICS_OPERATOR Nov 24 2003 2:20:38:903PM . . . . . . . . . . . . . . . . . . . . No power shot - computer problems ---------------------------------------------------------------------------- 1031124025 mossessian PHYSICS_OPERATOR Nov 24 2003 3:05:18:780PM . . . . . . . . . . . . . . . . . . . . Plasma. Current is doing the same ugly thing at 0.1 sec. Disrupts ~ 1.2 sec, probably because the inner strike point moves too far in. Next shot: move RXU out 1 cm at 1.2 - 1.4 sec to prevent upper x-point from moving in too far. It is possible that waiting for 15 min between shots instead of 10 min is a way to avoid fizzles every other shot. We are going to try that for the next shot. ---------------------------------------------------------------------------- 1031124026 mossessian PHYSICS_OPERATOR Nov 24 2003 3:23:26:826PM . . . . . . . . . . . . . . . . . . . . Fizzle. The "waiting longer" theory did not work Next shot: no changes ---------------------------------------------------------------------------- 1031124027 mossessian PHYSICS_OPERATOR Nov 24 2003 3:41:47:310PM . . . . . . . . . . . . . . . . . . . . Plasma. Outer strike point does not touch the corner up until ~1.5 sec when there is a burst of H-alpha and CII (probably because the strike point moves to the corner) Next shot: Move RXU out a little at 1.5 ses. ---------------------------------------------------------------------------- 1031124028 mossessian PHYSICS_OPERATOR Nov 24 2003 3:57:41:170PM . . . . . . . . . . . . . . . . . . . . Plasma. Next shot: no changes ---------------------------------------------------------------------------- 1031124029 mossessian PHYSICS_OPERATOR Nov 24 2003 4:14:50:780PM . . . . . . . . . . . . . . . . . . . . Plasma. Next shot: Go to LN configuration. Switch to segment 2 Move RXL in 2 cm Set target nl to 8e19 ---------------------------------------------------------------------------- 1031124030 mossessian PHYSICS_OPERATOR Nov 24 2003 4:36:19:230PM . . . . . . . . . . . . . . . . . . . . Fizzle ---------------------------------------------------------------------------- 1031124031 mossessian PHYSICS_OPERATOR Nov 24 2003 4:38:43:076PM . . . . . . . . . . . . . . . . . . . . Plasma. Lower triangularity is too high (.75 at 1.3 sec) Next shot: Increase RXL 1 cm at 1.4 sec to lower delta. Drop RXL 0.5 cm to increase upper delta. ---------------------------------------------------------------------------- 1031124032 mossessian PHYSICS_OPERATOR Nov 24 2003 4:59:27:873PM . . . . . . . . . . . . . . . . . . . . Fizzle. ---------------------------------------------------------------------------- 1031124033 mossessian PHYSICS_OPERATOR Nov 24 2003 4:59:54:263PM . . . . . . . . . . . . . . . . . . . . Plasma. Lower delta 0.65 as needed. Upper ramps up to 0.35. ,Lm@,Lm@ |
| Session Leader Comments | |||
| Nov 24 2003 08:58:59:450AM | Brian Labombard | 1031124 Run Plan MP#335 - Edge plasma flows in upper versus 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. Today's Run: This run is a continuation from 1031118. Today we are looking to start taking data from double-null discharges. Also, we would like to revisit high-density lower single null plasmas to see if the difference in upper-null and lower-null toroidal rotation tends to zero. We also want to try a slow SSEP sweep. For all non-SSEP sweep shots, we want left gap to be 13 mm and right gap to be 15 mm. This will allow the ISP to reach the separatrix and provide a reasonable SOL width at the outer midplane to look at flows. NINJA gas setup is 300 torr helium. All shots are nominally 0.8 MA, 5.3 tesla discharges Optional RF conditioning after 1.2 s Reload from shot#1031118018 with segment 4 turned on Set density program (in segment 4!) to NL04 = 0.8 This is a double-null plasma with SSEP feedback control. NOTE on shot#1031118018: Segment 2 - single null lower Segment 3 - single null upper Segment 4 - double null Shot Plan: Shot#1-4 (DN) Turn on segment 4 Program NL04 = 0.8x10^20 m^-2 Can proportional gain on SSEP be decreased to remove x-pt oscillations? Increase right gap by 3 mm (to 15 mm). Decrease left gap by 3 mm (to 13 mm). Check probe targeting. 5,6 - NL04 = 0.6, DN 7,8 - NL04 = 1.0, DN 9,10 - NL04 = 1.2, DN SSEP Scan Program slow SSEP sweep from lower to upper null ( -2 < SSEP < +2 cm) 11,12 - NL04 = 0.8 Revisit SNL reload Shot# 1031118016 (segment 2 active) 13, 14 - NL04 = 1.2 15, 16 - NL04 = 1.4 (if needed, to detach inner wall SOL) | |
| Nov 24 2003 09:35:36:967AM | 1031124003 | Brian Labombard | Shot 3 - DN, NL04=0.8, no probes scanning next shot: adjust gaps, scan probes |
| Nov 24 2003 10:17:26:170AM | 1031124005 | Brian Labombard | Shot 5 - DN, NL04=0.8, ASP, FSP, ISP scanning at 0.75, 0.95, 1.15s ASP - data kn, could be deeper FSP - data ok, could be deeper ISP - excellent data Next shot: repeat, tweak outer gap and RXL drift, reduce SSEP by 1mm |
| Nov 24 2003 10:47:46:793AM | 1031124007 | Brian Labombard | Shot 7 - DN, NL04=0.8, ASP, FSP, ISP scanning at 0.75, 0.95, 1.15s ASP - data ok, could be deeper FSP - data ok, could be deeper ISP - good first scan, problem with electronics on 2nd and 3rd scan Next shot: repeat, tweak inner and outer gap +1mm, probes deeper |
| Nov 24 2003 11:02:23:263AM | 1031124008 | Brian Labombard | Shot 8 - DN, NL04=0.8 and rising, ASP, FSP, ISP scanning at 0.75, 0.95, 1.15s ASP - data ok, still not deep enough! FSP - data great ISP - excellent data Next shot: repeat, ASP deeper! |
| Nov 24 2003 11:09:40:903AM | 1031124009 | Brian Labombard | Shot 9 - DN, NL04=0.87 - 0.93, ASP, FSP, ISP scanning at 0.75, 0.95, 1.15s ASP - data ok FSP - data great ISP - excellent data Next shot: go to NL04 = 0.6 |
| Nov 24 2003 11:32:54:590AM | 1031124010 | Brian Labombard | Shot 10 - DN, NL04=0.62 - 0.66, ASP, FSP, ISP scanning at 0.75, 0.95, 1.15s ASP - data ok FSP - data great ISP - excellent data Next shot: go to NL04 = 0.5 |
| Nov 24 2003 11:40:18:640AM | 1031124011 | Brian Labombard | Shot 11 - DN, NL04=0.54 - 0.61, ASP, FSP, ISP scanning at 0.75, 0.95, 1.15s ASP - excellent data FSP - data great ISP - excellent data Next shot: go to NL04 = 0.7 |
| Nov 24 2003 12:10:36:590PM | 1031124013 | Brian Labombard | Shot 13 - DN, NL04=0.7-0.74, ASP, FSP, ISP scanning at 0.75, 0.95, 1.15s ASP - good data FSP - data great ISP - excellent data Next shot: go to NL04 = 1.0 |
| Nov 24 2003 12:36:00:170PM | 1031124015 | Brian Labombard | Shot 15 - DN, NL04=1.0, ASP, FSP, ISP scanning at 0.75, 0.95, 1.15s ASP - good data, could be deeper FSP - data great ISP - excellent data, cold, can be deeper Next shot: go to NL04 = 1.2 |
| Nov 24 2003 01:12:50:903PM | 1031124017 | Brian Labombard | Shot 17 - DN, NL04=1.15-1.3, ASP, FSP, ISP scanning at 0.75, 0.95, 1.15s ASP - data ok, could be deeper FSP - ok ISP - ok Next shot: go to NL04 = 0.8 with SSEP sweep |
| Nov 24 2003 02:04:06:873PM | 1031124020 | Brian Labombard | Shot 20 - SEP scan (-4 to +4 mm) Lower to Uupper null, NL04=0.7-0.8, ASP, FSP, ISP scanning at 0.75, 0.95, 1.15s ASP - data ok FSP - ok ISP - ok Next shot: Lower null plasma, NL04 =0.75 |
| Nov 24 2003 02:11:39:403PM | 1031124022 | Brian Labombard | Shot 22 - Lower Single Null, NL04=0.75, ASP, FSP, ISP scanning at 0.75, 0.95, 1.15s ASP - data ok FSP - ok ISP - ok End of MP#335 |
| Nov 24 2003 02:28:10:857PM | 1031124023 | Amanda Hubbard | Starting MP 363, LH thresholds in LN, DN, USN and LSN configurations. (Naturally, CAMAC promptly hangs; no power shot). Assuming it recovers, we will start with the shot sequence as advertised in the MP. Step 1 is shape development in upper null, to improve coverage and s/n on ETS. Then progress through power scans in LSN, DN UN and limiter configurations. |
| Nov 24 2003 03:03:39:700PM | 1031124024 | Amanda Hubbard | started with a previous USN shot. As expected, its upper position is close to the outer ETS limit. Next shot we will try moving the x-pt in. L-Mode, ramped RF to 1.5 MW. Gaps ~ 1.2 cm (both), delta_u=0.56, delta_l=0.35, kappa=1.68, Ssep "40" (ie solid USN, I presume) |
| Nov 24 2003 03:42:28:857PM | 1031124025 | Amanda Hubbard | Moved x-pt in, Good coverage for ETS. But, disrupts ~ 1.2 s when xpt reaches the inner plate. RF ramps to 4 MW. Looks like brief L-H transition a t 1.12 s, just before disruption. Threshold 4 MW, Te9=400 eV, r/a=0.95. |
| Nov 24 2003 03:44:26:590PM | 1031124027 | Amanda Hubbard | Full length shot, up to 5 MW RF. But, Prad rises and Te cools from ~ 1.1 secs; L-mode. We appear to be heating something. Dmitri will tweak strike points. |
| Nov 24 2003 04:02:23:153PM | 1031124028 | Amanda Hubbard | Full length shot, up to 5.2 MW RF. Got a brief H-mode, at 1.154 s, 4.2 MW, Te9 500 eV at r/a=0.95. |
| Nov 24 2003 04:17:09:480PM | 1031124029 | Amanda Hubbard | Flat RF, 4.4 MW as requested. delta_u=0.65, delta_l=0.35, kappa=1.67 Got an H-mode fairly early, at ~0.788n s. Decent, steady H-mode until 1+ secs, followed by L-mode. Jerry reports good ETS profiles. No sign of big injections, though Prad rises in H-modes. Declaring the upper null shape development (Step 1 of MP) done. Moving to LSN for next shot, with power ramp. |
| Nov 25 2003 08:48:05:113AM | 1031124031 | Amanda Hubbard | LSN, with RF ramping to 5 MW. Got an H-mode very early (0.77 s). Later H-mode has 5 MW, ELMs. delta_l a little high; reduce on next shot. Also, less power IGOR. Threshold at Te9~135 eV. Prf=1 MW |
| Nov 25 2003 08:54:26:583AM | 1031124033 | Amanda Hubbard | LSN, with RF ramping Got an H-mode at 0.8913 s, Te9 ~ 140 eV, Prf onlt 0.83 MW. Later H-mode has 5 MW, ELMs. |
| Physics Operator Comments | |||
| Nov 24 2003 08:51:17:690AM | Dmitri Mossessian | Engineering Setup and Run Plan for 11/24/03 1/2 day of MP #335-Edge plasma flows in upper vs lower x-point discharges Session Leader: LaBombard 1/2 day MP #363 LH Threshold Session Leader: Hubbard Physics operator: Mossessian ECDC in D2 at 2e-4 Torr, stopping by 07:00. Bake at 60 C as well. Run begins at 09:00 and ends at 17:00. Power systems the same as on 1031114027 A-coils should be hooked up as on 1031114027 (+Dtop -Dbot -Jtop +Jbot). Enable the power supply. Gas setup: fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar Hybrid enabled (PG1) leave B-side upper as is Hybrid DISABLED (PG2) fill C-side with 30 psi D2 Hybrid enabled (PG3) Enable the following gate valves, assuming no vacuum problems: ECE, VUV, DNB RF Setup:Transmitters 1,2,3 & 4 in Run On by 08:00. _________________________________________________________ Reload from shot#1031118018 Turn on segment 4 Set density program (in segment 4!) to NL04 = 0.8 This is a double-null plasma with SSEP feedback control. NOTE on shot#1031118018: Segment 2 - single null lower Segment 3 - single null upper Segment 4 - double null Shot Plan: Shot#1-4 (DN) Turn on segment 4 Program NL04 = 0.8x1020 m^-2 Can proportional gain on SSEP be decreased to remove x-pt oscillations? Increase right gap by 3 mm (to 15 mm). Decrease left gap by 3 mm (to 13 mm). Check probe targeting. 5,6 - NL04 = 0.6, DN 7,8 - NL04 = 1.0, DN 9,10 - NL04 = 1.2, DN SSEP Scan Program slow SSEP sweep from lower to upper null ( -2 < SSEP < +2 cm) 11,12 - NL04 = 0.8 Revisit SNL reload Shot# 1031118016 (segment 2 active) 13, 14 - NL04 = 1.2 15, 16 - NL04 = 1.4 (if needed, to detach inner-wall SOL) | |
| Nov 24 2003 09:12:09:467AM | 1031124001 | Dmitri Mossessian | Data systems test. Seems to have a CAMAC problem with gas sygnals - no ratiomatic sysnal. Go for a plasma shot as is. |
| Nov 24 2003 09:24:08:717AM | 1031124002 | Dmitri Mossessian | Dud. Ratiomatic is back and showing a lot of pressure (~0.085) Wolfe thinks Bz is too low Next shot: Drop prepuff from 20 to 18 ms. Add 10 A to EF4 current to raise Bz a little. |
| Nov 24 2003 09:42:59:840AM | 1031124003 | Dmitri Mossessian | Plasma. Nice startup. Good double null. Next shot: Decrease left gap by 2 mm from .7 to 1.5, drop right gap 2 mm at 1.5 sec, leaving .7 sec value the same To do that - CLEARIN down 2 mm between 0.7 and 1.5 sec. RCUR down 1 mm at 0.75 sec |
| Nov 24 2003 10:00:00:250AM | 1031124004 | Dmitri Mossessian | Dud. Pressures and fields are no different from shot 3. Next shot - no change |
| Nov 24 2003 10:21:55:873AM | 1031124005 | Dmitri Mossessian | Plasma. Lower x-point is not very steady. RX_L ramps down 1 cm from .7 to 1.5 sec. Right gap is a bit too large according to Brian Next shot: RCUR down 1 mm at 0.75 and 1.5 mm at 1.5 sec RXL up 1 cm at 1.5 sec SSEP down -0.002 -> -0.003 Ar pulse 30 -> 50 msec |
| Nov 24 2003 10:23:53:857AM | 1031124006 | Dmitri Mossessian | Dud. Next shot - Jim will increase sparker voltage. No PCS changes. |
| Nov 24 2003 10:50:47:857AM | 1031124007 | Dmitri Mossessian | Plasma. As close to double null as we can get. Left gap is 1 mm smaller than needed. Next shot: CLEARIN up 1 mm A coil voltage down to 2500 |
| Nov 24 2003 11:03:22:530AM | 1031124008 | Dmitri Mossessian | Plasma. Disrupts at 1.57 for no apparent reason. Next shot: no PCS changes |
| Nov 24 2003 11:10:37:670AM | 1031124009 | Dmitri Mossessian | Plasma. Disrupts at 1.57 again. Next shot: nl down to .6e20. SSEP down to -0.001 at 1.7 sec |
| Nov 24 2003 11:27:11:123AM | 1031124010 | Dmitri Mossessian | Plasma. Next shot: nl down to 0.5e20 |
| Nov 24 2003 11:41:55:217AM | 1031124011 | Dmitri Mossessian | Plasma. Next shot: nl up to .7e20 |
| Nov 24 2003 11:53:45:230AM | 1031124012 | Dmitri Mossessian | No TF. Supply was not reset properly. Next shot: no change |
| Nov 24 2003 12:09:30:043PM | 1031124013 | Dmitri Mossessian | Plasma. Disrupted at 1.57 sec. It seems that density is too high when current starts ramping down. Next shot: End RF a little earlier to get out of H-mode when Ip starts going down. nl up to 1e20 |
| Nov 24 2003 12:25:00:937PM | 1031124014 | Dmitri Mossessian | Fizzle. Probably too much gas after disruption leads to slow current rise. We can't check it because the ratiomatic is dead. Next shot: no change |
| Nov 24 2003 12:34:34:030PM | 1031124015 | Dmitri Mossessian | Plasma. Next shot: Tweaked TF to get 5.4 T (at Amanda's request). nl up to 1.2e20 CLEARIN down 1 mm |
| Nov 24 2003 12:43:01:793PM | 1031124016 | Dmitri Mossessian | Fizzle. Fields, positions and current rise rate are exactly the same as on 15. Next shot: no change |
| Nov 24 2003 01:09:50:217PM | 1031124017 | Dmitri Mossessian | Plasma. Next shot: Do SSEP scan going from LN at 0.75 sec to UN at 1.15 sec. Set SSEP to -.005 at .75, -.003 at .95 and -.001 at 1.15 sec Increase gaps by 1 mm - CLEARIN up 1 mm nl back to 0.8e20 |
| Nov 24 2003 01:16:06:640PM | 1031124018 | Dmitri Mossessian | Fizzle. Everything seems to be the same as on a good shot, except for C radiation level. It is possible that after every good shot we have too much C in the machine which kills next plasma before it is born. We will try to drop the prepuff after next plasma to solve the problem. Next shot: no change |
| Nov 24 2003 01:33:22:437PM | 1031124019 | Dmitri Mossessian | Plasma. Nice SSEP scan. Next shot: Drop prepuff in segment 1 from 18 to 16 msec Try wider scan of SSEP from -.007 at .75 to +0.001 at 1.15 sec nl down to 0.7e20 |
| Nov 24 2003 01:45:33:107PM | 1031124020 | Dmitri Mossessian | Plasma. SSEP scan works. Next shot: Lower null. Turn segment 2 on. Change nl target to 7.5e19 |
| Nov 24 2003 01:50:03:543PM | 1031124021 | Dmitri Mossessian | Fizzle. Too much carbon again ? Next shot: no change |
| Nov 24 2003 02:09:38:280PM | 1031124022 | Dmitri Mossessian | Plasma. Next shot: Switching to MP#363 LH Threshold Switch to segment 3 of the same shot - upper null configuration. Set nl to 8e19 Drop prepuff to 15 msec Run Plan for MP 363 1) Establish the optimum shape for USN plasmas which gives the best pedestal region coverage and signal/noise on edge TS. Start from shots on in Brian's MP. Adjust shape as indicated by Jerry; cell access to adjust fibre positions if needed. This will determine kappa and delta for the other configurations. 2) Switch to LSN. 800 kA, ~ 5.4 T. 3-4 shots. a) Power ramp up to ~ 3 MW, to determine L-H threshold. b) Discharge with fixed power just below threshold, for 100-200 ms, followed by high power phase (4-5 MW). Repeat as needed for probe, HIREX. 3) Switch to DN . 5-6 discharges. a) 2 Discharges at power which gave L-H threshold in LSN (eg. 1 MW). Document ETS profiles, flows, rotation. b) Power ramp to maximum available (5 MW>) to determine the new L-H threshold. c) As above, make discharges with power just below L-H transition for ~ 200 ms, followed by higher power to get H-mode phase. |
| Nov 24 2003 02:20:38:903PM | 1031124023 | Dmitri Mossessian | No power shot - computer problems |
| Nov 24 2003 03:05:18:780PM | 1031124025 | Dmitri Mossessian | Plasma. Current is doing the same ugly thing at 0.1 sec. Disrupts ~ 1.2 sec, probably because the inner strike point moves too far in. Next shot: move RXU out 1 cm at 1.2 - 1.4 sec to prevent upper x-point from moving in too far. It is possible that waiting for 15 min between shots instead of 10 min is a way to avoid fizzles every other shot. We are going to try that for the next shot. |
| Nov 24 2003 03:23:26:827PM | 1031124026 | Dmitri Mossessian | Fizzle. The "waiting longer" theory did not work Next shot: no changes |
| Nov 24 2003 03:41:47:310PM | 1031124027 | Dmitri Mossessian | Plasma. Outer strike point does not touch the corner up until ~1.5 sec when there is a burst of H-alpha and CII (probably because the strike point moves to the corner) Next shot: Move RXU out a little at 1.5 ses. |
| Nov 24 2003 03:57:41:170PM | 1031124028 | Dmitri Mossessian | Plasma. Next shot: no changes |
| Nov 24 2003 04:14:50:780PM | 1031124029 | Dmitri Mossessian | Plasma. Next shot: Go to LN configuration. Switch to segment 2 Move RXL in 2 cm Set target nl to 8e19 |
| Nov 24 2003 04:36:19:230PM | 1031124030 | Dmitri Mossessian | Fizzle |
| Nov 24 2003 04:38:43:077PM | 1031124031 | Dmitri Mossessian | Plasma. Lower triangularity is too high (.75 at 1.3 sec) Next shot: Increase RXL 1 cm at 1.4 sec to lower delta. Drop RXL 0.5 cm to increase upper delta. |
| Nov 24 2003 04:59:27:873PM | 1031124032 | Dmitri Mossessian | Fizzle. |
| Nov 24 2003 04:59:54:263PM | 1031124033 | Dmitri Mossessian | Plasma. Lower delta 0.65 as needed. Upper ramps up to 0.35. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:57:51:123AM | Test | Ok | Shot Cycle |
| 2 | 09:13:06:280AM | Plasma | Ok | |
| 3 | 09:25:55:717AM | Plasma | Ok | |
| 4 | 09:49:02:700AM | Plasma | Ok | |
| 5 | 10:01:55:200AM | Plasma | Ok | |
| 6 | 10:17:52:640AM | Plasma | Ok | |
| 7 | 10:32:03:140AM | Plasma | Ok | |
| 8 | 10:51:01:200AM | Plasma | Ok | |
| 9 | 11:03:54:730AM | Plasma | Ok | |
| 10 | 11:20:56:327AM | Plasma | Ok | |
| 11 | 11:33:49:687AM | Plasma | Ok | |
| 12 | 11:46:35:123AM | Plasma | Bad | No TF |
| 13 | 11:57:38:390AM | Plasma | Ok | |
| 14 | 12:10:20:043PM | Plasma | Ok | |
| 15 | 12:24:33:543PM | Plasma | Ok | |
| 16 | 12:37:13:247PM | Plasma | Ok | |
| 17 | 12:49:53:577PM | Plasma | Ok | |
| 18 | 01:09:20:170PM | Plasma | Ok | |
| 19 | 01:22:08:373PM | Plasma | Ok | |
| 20 | 01:34:44:403PM | Plasma | Ok | |
| 21 | 01:47:11:513PM | Plasma | Ok | |
| 22 | 01:59:31:653PM | Plasma | Ok | |
| 23 | 02:11:56:903PM | Plasma | Bad | camac problem |
| 24 | 02:32:37:280PM | Plasma | Ok | |
| 25 | 02:53:56:047PM | Plasma | Ok | |
| 26 | 03:10:24:217PM | Plasma | Ok | |
| 27 | 03:22:42:030PM | Plasma | Ok | |
| 28 | 03:41:07:200PM | Plasma | Ok | |
| 29 | 04:00:12:420PM | Plasma | Ok | |
| 30 | 04:17:01:640PM | Plasma | Ok | |
| 31 | 04:29:35:780PM | Plasma | Ok | |
| 32 | 04:42:15:497PM | Plasma | Ok | |
| 33 | 04:54:31:430PM | Plasma | Ok | |