| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Brian Labombard |
| Physics operator(s): | Ron Parker,Steve Wolfe |
| Engineering operator(s): | Ed Fitzgerald |
| Engineering Operator Run Comment |
| MP#267-NL scan with reversed Bt and Ip SL:LaBombard PO:Parker EO:Fitzger |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:25:447PM |
| Author: To Be Determined |
| 11/16/00 run: MP#267 - reversed field "Dependence of SOL Fluctuations and Particle Transport on Collisionality" - reversed field, Day 2 Session Leader - B. LaBombard Phys Op - R. Parker ________________________________________________________________________________ Reason for today's run: From previous attempts at Day 2 of this MP (1001109 and 1001114) we only achieved the first half of the Day 2 plan, involving discharges at Ip=0.5 and 1.0 MA. The plan today was to complete the second half of the Day 2 plan, covering Bt=4 and 6 tesla discharges, to help us sort out between Ip and q scalings of the SOL transport/turbulence. ________________________________________________________________________________ Today's plan: Start with shot#1001109022 which was a recent 1.0 MA, 5.3 tesla, NL04 = 1.2 discharge (reversed Ip and Bt) with good probe targeting, gaps etc. Then change plasma current to 0.8 MA, Bt to 4 tesla, and NL04 = 0.6x10^20 m^-2. Shot#1-3 NL04 = 0.6x10^20 m^-2 Ip = 0.8 MA, Bt = 4 tesla Setup equilibrium and FSP/ASP target. Take two shots at each condition to optimize scanning probe insertion depths. 4,5 - NL04 = 0.6, Ip = 0.8, Bt = 4 6,7 - NL04 = 0.9, Ip = 0.8, Bt = 4 8,9 - NL04 = 1.2, Ip = 0.8, Bt = 4 10,11 - NL04 = 1.2, Ip = 0.8, Bt = 6 12,13 - NL04 = 0.9, Ip = 0.8, Bt = 6 14,15 - NL04 = 0.6, Ip = 0.8, Bt = 6 16,17 - NL04 = 0.5, Ip = 0.53, Bt = 5.3 18,19 - NL04 = 0.7, Ip = 0.53, Bt = 5.3 20,21 - NL04 = 0.9, Ip = 0.53, Bt = 5.3 22,23 - NL04 = 1.0, Ip = 1.06, Bt = 5.3 24,25 - NL04 = 1.3, Ip = 1.06, Bt = 5.3 26,27 - NL04 = 0.7, Ip = 1.06, Bt = 5.3 ________________________________________________________________________________ Results: The string of misfortune associated with this MP continued again today. This time the 13.8 kV connection to Cambridge Electric was went down just after shot #7. But, like a bad penny, we will return tomorrow to try this MP again. We did get 4 shots at NL04=0.6, completing that density data point at Bt=4 tesla. Three of these shots were used to scan the 'burping' FSP at three depths in the SOL where some interesting strong parallel and perpendicular flows were indicated by the C2D4 plumes. These plumes seem to support the hypothesis that when there are large parallel flows in the SOL (as indicated on the Mach probe) there are also large ExB flows in the SOL such that the vector sum of the two leads to primarily a toroidal flow, i.e., the poloidal projection of the total flow velocity towards or away from the divertor is relatively small. This observation goes a long way to explain the 'reversed flows' previously seen in the divertor under 'normal' Bt and Ip directions. Thus, a simple picture of SOL flows appears to be emerging, consistent with the 'main-chamber recycling' picture: The poloidal plasma flow to the divertor is small in the MCR regime. So any large ExB flows are 'cancelled' for the most part by flows parallel to B, such that the total plasma flow towards the divertor remains small. (Stated another way, the plasma just 'chooses' to rotate in the toroidal direction in response to the radial electric field in the SOL.) Thus the 'reversed flows' seen previously in normal Bt/Ip operation do not bring plasma out of the divertor. They just cancel the ExB flow. This observation also suggests that 'reversed parallel flows' play little or no role in the impurity retention characteristics of the divertor. ________________________________________________________________________________ Shot Notes: Setup for this run, unless otherwise noted: ASP and FSP N-S in Vf mode, E-W in SINGLE probe sweep mode ASP still has problem with shorts on East probe. Shot 1 - Ip =0.8, NL04 =0.6, Bt=4.2 tesla ASP and FSP scanning at .7, .95, and 1.2 seconds FSP and ASP in far SOL - no plumes. NOTE: FSP E & W probes were not operating on this shot! Shot 4 - Ip =0.8, NL04 =0.6, Bt=4.0 tesla ASP and FSP scanning at .7, .95, and 1.2 seconds FSP in far SOL, ASP near separatrix, plumes NOTE: FSP E & W probes were not operating on this shot! Shot 5 - Ip =0.8, NL04 =0.6, Bt=4.0 tesla ASP and FSP scanning at .7, .95, and 1.2 seconds FSP nearer to LCFS, ASP should be across separatrix, plumes NOTE: FSP W probe was not operating on this shot!! Shot 7 - Ip =0.8, NL04 =0.6, ramping up from He puff, Bt=4.0 tesla ASP and FSP scanning at .7, .95, and 1.2 seconds Very nice data on FSP and ASP with plumes |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:37:12:677PM |
| Author: To Be Determined |
| ENGINEERING SETUP AND RUN PLAN: The Engineering Setup and Run Plan for 1001116 was the same as that posted for Run 1001114, which was scuttled due to computer problems. Engineering Setup for Thursday, November 16 MP#267 - NL scan with reversed Bt and Ip SL: LaBombard PO: Parker Engineering setup: ------------------- Overnight ECDC in D2, stopping 1-2 hours before run. Run begins 9:00 and ends at 15:00 Power System Setup: Same as on 1001109022 Gas setup - fill B-top with 6 psi of D2 Hybrid enabled fill B-side lower with 1 psi of Ar Hybrid DISABLED fill B-side upper with 35 psi of D2 Hybrid DISABLED, for ECDC fill C-side with 30 psi of D2 Hybrid enabled leave J-bottom as is Hybrid DISABLED The following gate valves should be enabled, assuming no vacuum problems: ECE, VUV, DNB, Beast The following transmitters should be turned on 1, 2, and 4 Run Plan (LaBombard) ------------------- Start with shot#1001109022 which was a recent 1.0 MA, 5.3 tesla, NL04 = 1.2 discharge (reversed Ip and Bt) with good probe targeting, gaps etc. except change plasma current to 0.8 MA, ramp Bt down to 4 tesla, and NL04 = 0.6x10^20 m^-2. Shot#1-3 NL04 = 0.6x10^20 m^-2 Ip = 0.8 MA, Bt = 4 tesla Setup equilibrium and FSP/ASP target. Take two shots at each condition to optimize scanning probe insertion depths. 4,5 - NL04 = 0.6, Ip = 0.8, Bt = 4 6,7 - NL04 = 0.9, Ip = 0.8, Bt = 4 8,9 - NL04 = 1.2, Ip = 0.8, Bt = 4 10,11 - NL04 = 1.2, Ip = 0.8, Bt = 6 12,13 - NL04 = 0.9, Ip = 0.8, Bt = 6 14,15 - NL04 = 0.6, Ip = 0.8, Bt = 6 16,17 - NL04 = 0.5, Ip = 0.53, Bt = 5.3 18,19 - NL04 = 0.7, Ip = 0.53, Bt = 5.3 20,21 - NL04 = 0.9, Ip = 0.53, Bt = 5.3 22,23 - NL04 = 1.0, Ip = 1.06, Bt = 5.3 24,25 - NL04 = 1.3, Ip = 1.06, Bt = 5.3 26,27 - NL04 = 0.7, Ip = 1.06, Bt = 5.3 RUN SUMMARY: The run began well with the first shot running as programmed (see above Run Plan for parameters). However, the next shot fizzled and shot 3 was a no power shot necessitated by a computer hangup after shot 2. Shot 4 ran well with some minor tuning of BR and EF4 current. Shot 5 also ran well, except for a startup problem around 17 ms which was indicated by a burst in H Alpha and CII, as well as an outward excursion. After shot 6 fizzled, the derivative gain for RCUR was reduced from 6 to 2 for the first 40 ms in an attempt to cure the above startup problem. Shot 7 ran well, as programmed, however CELCO lost the 13.8 kV power 7 s into the shot. Since there was no possibility to resume the run, the run was aborted. The tuning of the derivative gain on RCUR may have helped the startup slightly, but did not cure the problem. |
| Session Leader Comments | |||
| Nov 16 2000 09:05:04:483AM | Brian Labombard | Run Plan for second day of MP#267 - NL scan with reversed Bt and Ip "Dependence of SOL Fluctuations and Particle Transport on Collisionality" The purpose of these experiments is to explore the dependence of SOL fluctuation characteristics and attendant cross-field particle transport on the collisionality of the SOL. The key diagnostics which must be operational for this study are: (a) A-port and F-port scanning probes operated in a fluctuation mode, (b) divertor probes operated in a fluctuation mode, (c) fast visible diodes viewing helium puffed from the A/B limiter capillary, (d) tangential Ly-alpha diode array, (e) limiter particle flux probes, and (f) edge thomson scattering. Day 2: Coarse density scans at different reversed plasma currents and reversed toroidal fields Run Plan: Reload shot#1001109022 which was a recent 1.0 MA, 5.3 tesla, NL04 = 1.2 discharge (reversed Ip and Bt) with good probe targeting, gaps etc. and change plasma current to 0.8 MA, Bt to 4 tesla, and NL04 = 0.6x10^20 m^-2. Shot#1-3 NL04 = 0.6x10^20 m^-2 Ip = 0.8 MA, Bt = 4 tesla Setup equilibrium and FSP/ASP target. Take two shots at each condition to optimize scanning probe insertion depths. 4,5 - NL04 = 0.6, Ip = 0.8, Bt = 4 6,7 - NL04 = 0.9, Ip = 0.8, Bt = 4 8,9 - NL04 = 1.2, Ip = 0.8, Bt = 4 10,11 - NL04 = 1.2, Ip = 0.8, Bt = 6 12,13 - NL04 = 0.9, Ip = 0.8, Bt = 6 14,15 - NL04 = 0.6, Ip = 0.8, Bt = 6 16,17 - NL04 = 0.5, Ip = 0.53, Bt = 5.3 18,19 - NL04 = 0.7, Ip = 0.53, Bt = 5.3 20,21 - NL04 = 0.9, Ip = 0.53, Bt = 5.3 22,23 - NL04 = 1.0, Ip = 1.06, Bt = 5.3 24,25 - NL04 = 1.3, Ip = 1.06, Bt = 5.3 26,27 - NL04 = 0.7, Ip = 1.06, Bt = 5.3 | |
| Nov 16 2000 09:19:15:983AM | 1001116001 | Brian Labombard | Setup for this run, unless otherwise noted: ASP and FSP N-S in Vf mode, E-W in SINGLE probe sweep mode ASP still has problem with shorts on East probe. Shot 1 - Ip =0.8, NL05 =0.6, Bt=4.2 tesla ASP and FSP scanning at .7, .95, and 1.2 seconds FSP and ASP in far SOL Next shot: Repeat with Bt ramped up to 5.3 tesla by 1.3 seconds.(for RF) Also, turn on C2D4 plumes |
| Nov 16 2000 10:29:08:983AM | 1001116004 | Brian Labombard | Shot 4 - Ip =0.8, NL05 =0.6, Bt=4.0 tesla ASP and FSP scanning at .7, .95, and 1.2 seconds FSP in far SOL, ASP near separatrix NOTE: FSP E & W probes were not operating on this shot and shot #1!! Next shot: Repeat with FSP closer to LCFS and ASP deeper inserted. |
| Nov 16 2000 10:40:48:310AM | 1001116005 | Brian Labombard | Shot 5 - Ip =0.8, NL05 =0.6, Bt=4.0 tesla ASP and FSP scanning at .7, .95, and 1.2 seconds FSP nearer to LCFS, ASP should be across separatrix NOTE: FSP W probe was not operating on this shot!! Next shot: Repeat again with FSP close to LCFS and ASP deeper inserted. |
| Nov 16 2000 11:14:47:403AM | 1001116007 | Brian Labombard | Shot 7 - Ip =0.8, NL05 =0.6, ramping up from He puff, Bt=4.0 tesla ASP and FSP scanning at .7, .95, and 1.2 seconds Very nice data on FSP and ASP with plumes Next shot: go to NL05 ~ 0.9 |
| Physics Operator Comments | |||
| Nov 16 2000 09:39:52:890AM | 1001116001 | Ron Parker | Shot 1 ran as programmed. |
| Nov 16 2000 09:39:33:200AM | 1001116002 | Ron Parker | Shot 2 was a fizzle. We will retune BR offset (2.0 mT to 1.5 mT) and EF4 current (1335 to 1325 A) for next shot. |
| Nov 16 2000 09:44:31:280AM | 1001116002 | Ron Parker | Hold for shot 3 due to computer hangup. Next shot will be a no power shot. |
| Nov 16 2000 09:51:08:607AM | 1001116003 | Ron Parker | Shot 3 ran as programmed. (No power, no plasma) |
| Nov 16 2000 09:56:25:577AM | 1001116003 | Ron Parker | For next shot, the field will be reduced to 4 T (from 4.2 T), but ramped back to 5.2 T at end of shot for the RF). |
| Nov 16 2000 10:16:20:607AM | 1001116004 | Ron Parker | Shot 4 ran as programmed, with B = 4 T, and a ramp to 5.2 at the end. Startup was good. Next shot, no changes except field ramp at end will begin at 1.2 instead of 1.25 s. |
| Nov 16 2000 10:48:56:670AM | 1001116005 | Ron Parker | Shot 5 had no changes and ran well, except for early burst of H alpha and CII around 17 msec. |
| Nov 16 2000 10:50:48:123AM | 1001116006 | Ron Parker | Shot 6 fizzled. At suggestion of Steve Wolfe, the derivative gain on RCUR was reduced for the first 40 msec (from 6 to 2) to try to cure the early outward bounce. No other changes for next shot. |
| Nov 16 2000 10:59:51:607AM | 1001116007 | Ron Parker | Shot 7 ran as programmed. |
| Nov 16 2000 11:00:39:187AM | 1001116007 | Ron Parker | Steve Wolfe will take over for R. Parker for next few shots. |
| Nov 16 2000 11:05:54:763AM | 1001116007 | Steve Wolfe | shot#7: Wolfe in for Parker. There was an alternator fault after shot 7. Data seems to not be coming through. IGOR thinks we are still in PULSE state 6 minutes after the shot. Next shot: change nl4 to 0.9e20 |
| Nov 16 2000 11:20:16:950AM | 1001116007 | Steve Wolfe | shot#7: Dropping the derivativ rcur gain did not completely cure the outside bounce. Seems to have no engineering data (bus rogs, ps volts, etc) Eng CAMAC failed. Next shot: change nl4 to 0.9e20 |
| Nov 16 2000 11:41:19:250AM | 1001116007 | Steve Wolfe | shot#7: Dropping the derivativ rcur gain did not completely cure the outside bounce. Seems to have no engineering data (bus rogs, ps volts, etc) Eng CAMAC failed. Next shot: change nl4 to 0.9e20; also, increase pg4 puff from 22msec to 24msec. (If it happens; CELCO lost a cable in Central Sq., causing experimental power to go down. We're on UPS now.) |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:03:27:590AM | Plasma | Ok | |
| 2 | 09:21:14:750AM | Plasma | Ok | |
| 3 | 09:46:02:030AM | Plasma | Bad | IGOR delay too long, No power shot taken |
| 4 | 09:58:34:357AM | Plasma | Ok | |
| 5 | 10:18:51:437AM | Plasma | Ok | |
| 6 | 10:39:50:013AM | Plasma | Ok | |
| 7 | 10:57:27:437AM | Plasma | Ok | |