| Miniproposals | ||||||||||
|
| Operators | |
| Session leader(s): | Brian Labombard |
| Physics operator(s): | Robert Granetz |
| Engineering operator(s): | Ed Fitzgerald |
| Engineering Operator Run Comment |
| Mp #475 Cryo Pump start up with reverse field S/L Labombard P/O Granetz |
| Session Leader Plans |
| Entered: Jul 19 2007 10:18:46:997PM |
| Author: Brian Labombard |
| Run Plan for 1070720 MP#475 ""Cryopump Startup"" - with reversed field Goal Revisit cryopumping throughput and gas pressure behavior in LSN, USN, near DN and DN plasmas with reversed Bt. Plan (A) First we will re-run some shots from the 1070525 and 1070601 runs in reversed Bt & Ip and look for differences. Shots to repeat with reversed Bt: 1070525013 - Pump WARM, USN, Ip=0.8, NL04=0.85, Bt=5.47 (We already ran this in reversed Bt - 1070718029) 1070525014 - Pump COLD, USN, Ip=0.8, NL04=0.8, dropping after 1.1s, Bt=5.47 (We already ran this in reversed Bt - 1070718030) 1070525006 - Pump WARM, LSN, Ip=0.8, NL04=0.75, Bt=5.47 1070525016 - Pump COLD, USN, Gas puff shutoff at 0.5 s, Ip=0.8, NL04=0.78 dropping to 0.4 in about 1 sec, Bt=5.47 1070525018 - Pump WARM, USN, Gas puff shutoff at 0.5 s, Ip=0.8, NL04=0.86 dropping to 0.72 in about 1 sec, Bt=5.47 1070525024 - Pump COLD, USN, Flat NL04 program of 1.0, Ip=0.8, NL04=0.9 to 1.05 s, dropping to 0.73, Bt=5.47 if piezo can not compete with cryopump in the above shot, then re-run this shot also: 1070525026 - Pump COLD, USN, Flat NL04 program of 1.0, Ip=0.8, Very flat NL04=0.94, Bt=5.47 Argon puff NINJA D2 at 1370 torr, trig: 0.3 duration: 1.0 Ninja puffs 50 torr-l/s 1070525029 - Pump COLD, DN, Flat NL04 program of 1.0, SSEP close to 0, Ip=0.8, Very Flat NL04=1.0, Bt=5.47 Argon puff No NINJA 1070525031 - Pump COLD, LSN, Flat NL04 program of 1.0, SSEP= ~-6mm drifting to -3mm, Ip=0.8, Very flat NL04=1.0, Bt=5.38 Argon puff 1070601020 - Pump COLD, USN, outer gap at 13 mm, NL04=1.0 with valve off at 0.8s, Ip=1.0, Bt=5.45 No Argon 1070601029 - Pump COLD, flat NL04= 0.9 then gas turn off at 0.6 s, SSEP jog to +5 mm at 0.7 s, Ip=1.0, Bt=5.45 (B) Then we can try playing with the upper divertor x-point and strike-point locations. Start with the USN plasma resulting from the repeat of 1070525024. First move upper x-point out in major radius. Then move upper x-point up, bringing flux from inner divertor leg onto pumping slot. Run with pump on and off. |
| Physics Operators Plans |
| Entered: Jul 19 2007 04:48:52:617PM |
| Author: Robert Granetz |
Engineering setup for Friday 20 July 2007
MP#475 Explore cryopumping of upper null plasmas w/reversed field
possibly also Idea#907, if the primary MP doesn't take the entire day
Session leaders: B. LaBombard (and maybe J. Terry if we have time)
Physics operator: R. Granetz
ECDC overnight in D2, pressure=2e-4 Torr. Rmin/Rdwell/Rmax = 44/45/103 cm.
Bake at 60 C.
Power systems as on 1070718029 (0.8 MA, 5.4 T, 0.8e20 m-2, upper null, rev BT)
A-coil configuration: -Dtop +Dbot +Jtop -Jbot; Enabled.
Gas Setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar Hybrid DISABLED (PG1)
leave B-side upper as is Hybrid DISABLED (PG2)
fill B-main (C-side) with 40 psi D2 Hybrid enabled (PG3)
leave NINJA as is DISABLED
Enable the following gate valves and shutters, assuming no vacuum problems:
ECE, VUV, Z-bolo shutters
Torvac setup: gate valves closed for 5 minutes after the shot
Specific diagnostics: divertor probes, pressure gauges
-------------------------------------------------------------------------------
ICRF Setup: all transmitters ready for run-on by 08:30 (not in run on)
LH Setup: no LH for this run
DNB: no
Cryopump: YES!!!!
-------------------------------------------------------------------------------
Run plan: see Brian's run plan. If we have time later in the day, we might
try to do more of Jim Terry's run from Thursday.
|
| Session Leader Summaries |
| Entered: Jul 22 2007 10:42:56:797PM |
| Author: Brian Labombard |
| Run Summary for 1070720 MP#475 ""Cryopump Startup"" - with reversed field This run has hastily scheduled after it was found during Jerry's run (1070718 - MP#506 ""H-modes with cryopumping in upper single null topology"") that the cryopump did not seem be as effective in particle removal for reversed field as it had been with forward field. It was speculated that in-out divertor asymmetries were to blame, with reversed field tending to favor a lower level of plasma-recycling on the outer strike point - the location of the upper divertor pumping slot. The goal of this run was to address this physics explanation by comparing the divertor gas pressure and pumping behavior in otherwise identical reversed field discharges. Based on the results today, it is clear that field reversal does indeed affect the divertor pressures and particle pumping throughput behavior of the upper divertor cryopump in USN discharges. However, at high plasma densities (NL04 ~ 1e20), the gas pressures and particle throughputs are essentially unchanged with field reversal. Only when the plasma density is lowered do the differences show up - and they can be quite dramatic. Gas pumping throughputs were found to be lower by about a factor of three in reversed-B USN discharges with NL04 ~ 0.8e20 (shot 15) - a not-very-low plasma density. In contrast, reversed-B USN discharges with NL04 ~ 1.0e20 exhibited very high gas throughputs of ~140 torr-l/s (shot 6), matching the 'trophy results' with forward-B. Static pressures in the upper crypump plenum were mapped out as a function of NL04 on shots 21, 23, 26. The pressures were found to drop off dramatically with decreasing NL04 - less than 1 mtorr for NL04 < 0.8e20 but up to 41 mtorr for NL04 ~ 1e20! Running a double-null topology was found to improve the situation (shots 29, 31, 33) - as one might anticipate since this configuration keeps parallel plasma flows from putting particles were they can not be pumped, the inner divertor legs. For example, 3 mtorr of static upper divertor pressure was maintained at NL04 ~ 0.75 (shot 33), and exhibiting ~15 torr-l/s gas throughput when the pump was turned on (shot 34). We thought that we might also try today a few discharges with the upper inner divertor strike point moved way out in major radius, far enough for the gas evolving there (via volume recombination in the detached inner divertor leg) to communicate with the pumping slots. Anyway this idea is a bit dangerous for future high-power discharges. The upper divertor beveled tile shapes are not designed to accommodate such a large radial displacement in strike point locations. ___________________________________________________________________________________ Shot log 1 - Attempted repeat of shot 1070525006 with reversed field - disrupted early F-cryo MKS is very noisy. 2 - re-run of 1070525006 with reversed field, LSN, Ip=0.8, NL04=0.75 lower divertor pressures are lower than with normal field 3 - re-run of 1070525016 with reversed field, USN, Gas puff shutoff at 0.5 s, Ip=0.8, pump ON NL04 ~ 0.8 and similarly drooping, Cryo and G-side pressures are lower ohmic H-mode at 0.7 s 4 - re-run of 1070525018 with reversed field, USN, Gas puff shutoff at 0.5 s, Ip=0.8, pump OFF NL04 ~ 0.8 and dropping a little faster Cryo and G-side pressures are much lower 5 - re-run of 1070525024 with reversed field, USN, Flat NL04 program of 1.0, Ip=0.8, pump ON NL04 tracks the same, gas throughput is identical, piezo valve can not keep up G-side pressure is a little lower. 6 - re-run of 1070525026 with reversed field, USN, Flat NL04 program of 1.0, Ip=0.8, Argon puff, pump ON NINJA D2 at 1319 torr, trig: 0.3 duration: 1.0 Ninja puffs 46 torr-l/s Similar injection rate, ~140 torr-l/s G-side lower, lower div pressure lower, Cryo lower (slightly) 7 - re-run of 1070525029 with reversed field, DN, Flat NL04 program of 1.0, Ip=0.8, Argon puff, pump ON Identical flat NL04 ~ 1.0, 75 torr-l/s throughput is identical All pressures are also identical 8 - re-run of 1070525031 with reversed field, pump ON LSN, Flat NL04 program of 1.0, SSEP= ~-6mm Ip=0.7 (not matching 0.8!), Idential gas injection rate and NL04 G-side pressures higher 9 - re-run of 1070601020 with reversed field, pump ON USN, outer gap at 13 mm, NL04=1.0 with valve off at 0.8s got an ohmic H-mode, Ip=0.92 MA not 1 MA Cryo pressures match pretty well. 10- re-run of 1070601020 with reversed field, pump ON USN, outer gap at 13 mm, NL04=1.0 with valve off at 0.8s NL04 running high, ~1.2, Cryo pressures correspondingly higher 11- re-run of 1070601029 with reversed field, pump ON, Argon Off flat NL04= 0.9 then gas turn off at 0.6 s, SSEP jog to +3 mm at 0.7 s, Ip=1.0 Similar NL04 pumpout, Disrupted at 1.5 s. Identical Cryo pressures 12- re-run of 1070601029 with reversed field, pump ON, Argon On flat NL04= 0.9 then gas turn off at 0.6 s, SSEP jog to +3 mm at 0.7 s, Ip=1.0 Identical NL04 pumpout and Cryo pressures 13- no power shot 14- re-run of 1070525013 with reversed field (same as 1070718029), pump OFF USN, Ip=0.8, NL04=0.85 flat, Cryo pressures clearly lower with reversed B 15- re-run of 1070525014 with reversed field (same as 1070718030), pump On USN, Ip=0.8, NL04=0.8 flat then drooping, Gas throughput is lower by a factor of ~3 Upper divertor Isats are lower by a factor of 2. 16- re-run of 1070601020 with reversed field, try to get NL04=1.0, pump ON USN, program NL04=1.0 with valve off at 0.8s NL04 still too high (1.2), ohmic H-mode starts early at 0.59s 17- repeat of 16, pump ON NL04 behavior and H-mode behavior are identical 18- repeat of 17 with pump OFF No H-mode. Cryo at 25 mtorr with NL04 = 1.1 19 - fizzle 20 - Reload shot#5, USN, Ip=0.8, flat NL04 programmed to 0.8, Pump ON NL04 ~ 0.9, 0.5 mtorr in upper chamber, around 15 torr-l/s. 21 - Repeat 20 with pump off NL04 ~ 0.9, Peak cryo pressure is 12 mtorr, lithium pellet 22 - Repeat with NL04 ~ 0.8 (program 0.7), Pump ON NL04~ .75 got two H-modes 23 - Repeat with pump OFF, NL04 ~ 0.85 NL04 ~ 0.8, Peak cryo pressure is 0.9 mtorr 24 - Drop NL04 by 0.1, Pump OFF Ohmic H-modes. 25 - Repeat with Cryopump ON Ohmic H-modes 26 - Repeat, NL04 ~0.9, Pump ON Peak cryo pressure is 3 mtorr 27 - Repeat, NL04 ~1.0, Pump OFF Peak cryo pressure is 41 mtorr. 28 - fizzle 29 - Reload shot#7, NL04 ~ 0.94 DN, SSEP ~ 0, Flat NL04 program of 0.94, Ip=0.8, pump OFF Cryo pressure is 16 mtorr, B-bottom is 14 mtorr 30 - fizzle 31 - DN, SSEP ~ 0, Flat NL04~ 0.85, Ip=0.8 pump OFF Cryo pressure is 8 mtorr, B-bottom is 8 mtorr 32 - fizzle 33 - DN, SSEP ~ 0, Flat NL04~0.75, Ip=0.8 pump OFF Cryo pressure is 3 mtorr, B-bottom is 3 mtorr 34 - DN, SSEP ~ 0, Flat NL04~0.75, Ip=0.8 pump ON Cryo pressure is 0.6 mtorr, B-bottom is 2 mtorr |
| Physics Operator Summaries |
| Entered: Jul 20 2007 05:08:27:347PM |
| Author: Robert Granetz |
Run summary for Friday 20 July 2007
MP#475 Explore cryopumping of upper null plasmas w/reversed field
Session leaders: B. LaBombard
Physics operator: R. Granetz
This run involved running reversed field configurations that matched
previous discharges in normal field. A large number of upper null, double
null, and lower null configurations were run, with and without the cryopump
on. Much information on the pumping effectiveness in reversed field was
obtained and is described in detail in the session leader's report. Power
supplies and shot cycle software ran reliably today, and plasma startup was
very reliable except for a few fizzles late in the day. This may have been
because of a small N2 leak around the end of the day, possibly due to the
vessel temperature getting down to 13 C. The RGA was showing a 10-fold
increase in mass 28.
Scorecard: 29 plasmas
0 duds
4 fizzles
0 power supply tests
1 no-power MDS shot cycles
--------------
Total: 34 shot cycles
|
| Session Leader Comments | |||
| Jul 20 2007 09:39:15:210AM | 1070720001 | Brian Labombard | 1 - Attempted repeat of shot 1070525006 with reversed field - disrupted early F-cryo MKS is very noisy. |
| Jul 20 2007 09:58:38:953AM | 1070720002 | Brian Labombard | 2 - re-run of 1070525006 with reversed field, pump WARM lower divertor pressures are lower than with normal field |
| Jul 22 2007 09:06:10:637PM | 1070720003 | Brian Labombard | 3 - re-run of 1070525016 with reversed field, USN, Gas puff shutoff at 0.5 s, Ip=0.8, pump ON NL04 ~ 0.8 and similarly drooping, Cryo and G-side pressures are lower ohmic H-mode at 0.7 s |
| Jul 22 2007 09:06:42:357PM | 1070720004 | Brian Labombard | 4 - re-run of 1070525018 with reversed field, USN, Gas puff shutoff at 0.5 s, Ip=0.8, pump OFF NL04 ~ 0.8 and dropping a little faster Cryo and G-side pressures are much lower |
| Jul 22 2007 09:06:57:887PM | 1070720005 | Brian Labombard | 5 - re-run of 1070525024 with reversed field, USN, Flat NL04 program of 1.0, Ip=0.8, pump ON NL04 tracks the same, gas throughput is identical, piezo valve can not keep up G-side pressure is a little lower. |
| Jul 22 2007 09:07:11:120PM | 1070720006 | Brian Labombard | 6 - re-run of 1070525026 with reversed field, USN, Flat NL04 program of 1.0, Ip=0.8, Argon puff, pump ON NINJA D2 at 1319 torr, trig: 0.3 duration: 1.0 Ninja puffs 46 torr-l/s Similar injection rate, ~140 torr-l/s G-side lower, lower div pressure lower, Cryo lower (slightly) |
| Jul 22 2007 09:07:22:387PM | 1070720007 | Brian Labombard | 7 - re-run of 1070525029 with reversed field, DN, Flat NL04 program of 1.0, Ip=0.8, Argon puff, pump ON Identical flat NL04 ~ 1.0, 75 torr-l/s throughput is identical All pressures are also identical |
| Jul 22 2007 09:07:42:730PM | 1070720008 | Brian Labombard | 8 - re-run of 1070525031 with reversed field, pump ON LSN, Flat NL04 program of 1.0, SSEP= ~-6mm Ip=0.7 (not matching 0.8!), Idential gas injection rate and NL04 G-side pressures higher |
| Jul 22 2007 09:07:55:747PM | 1070720009 | Brian Labombard | 9 - re-run of 1070601020 with reversed field, pump ON USN, outer gap at 13 mm, NL04=1.0 with valve off at 0.8s got an ohmic H-mode, Ip=0.92 MA not 1 MA Cryo pressures match pretty well. |
| Jul 22 2007 09:08:11:827PM | 1070720010 | Brian Labombard | 10- re-run of 1070601020 with reversed field, pump ON USN, outer gap at 13 mm, NL04=1.0 with valve off at 0.8s NL04 running high, ~1.2, Cryo pressures correspondingly higher |
| Jul 22 2007 09:08:23:857PM | 1070720011 | Brian Labombard | 11- re-run of 1070601029 with reversed field, pump ON, Argon Off flat NL04= 0.9 then gas turn off at 0.6 s, SSEP jog to +3 mm at 0.7 s, Ip=1.0 Similar NL04 pumpout, Disrupted at 1.5 s. Identical Cryo pressures |
| Jul 22 2007 09:08:34:937PM | 1070720012 | Brian Labombard | 12- re-run of 1070601029 with reversed field, pump ON, Argon On flat NL04= 0.9 then gas turn off at 0.6 s, SSEP jog to +3 mm at 0.7 s, Ip=1.0 Identical NL04 pumpout and Cryo pressures |
| Jul 22 2007 09:08:53:077PM | 1070720014 | Brian Labombard | 14- re-run of 1070525013 with reversed field (same as 1070718029), pump OFF USN, Ip=0.8, NL04=0.85 flat, Cryo pressures clearly lower with reversed B |
| Jul 22 2007 09:09:06:140PM | 1070720015 | Brian Labombard | 15- re-run of 1070525014 with reversed field (same as 1070718030), pump On USN, Ip=0.8, NL04=0.8 flat then drooping, Gas throughput is lower by a factor of ~3 Upper divertor Isats are lower by a factor of 2. |
| Jul 22 2007 09:09:18:297PM | 1070720016 | Brian Labombard | 16- re-run of 1070601020 with reversed field, try to get NL04=1.0, pump ON USN, program NL04=1.0 with valve off at 0.8s NL04 still too high (1.2), ohmic H-mode starts early at 0.59s |
| Jul 22 2007 09:09:34:920PM | 1070720017 | Brian Labombard | 17- repeat of 16, pump ON NL04 behavior and H-mode behavior are identical |
| Jul 22 2007 09:09:59:860PM | 1070720018 | Brian Labombard | 18- repeat of 17 with pump OFF No H-mode. Cryo at 25 mtorr with NL04 = 1.1 |
| Jul 22 2007 09:10:15:377PM | 1070720020 | Brian Labombard | 20 - Reload shot#5, USN, Ip=0.8, flat NL04 programmed to 0.8, Pump ON NL04 ~ 0.9, 0.5 mtorr in upper chamber, around 15 torr-l/s. |
| Jul 22 2007 09:10:25:563PM | 1070720021 | Brian Labombard | 21 - Repeat 20 with pump off NL04 ~ 0.9, Peak cryo pressure is 12 mtorr, lithium pellet |
| Jul 22 2007 09:10:35:970PM | 1070720022 | Brian Labombard | 22 - Repeat with NL04 ~ 0.8 (program 0.7), Pump ON NL04~ .75 got two H-modes |
| Jul 22 2007 09:10:47:970PM | 1070720023 | Brian Labombard | 23 - Repeat with pump OFF, NL04 ~ 0.85 NL04 ~ 0.8, Peak cryo pressure is 0.9 mtorr |
| Jul 22 2007 09:11:01:000PM | 1070720024 | Brian Labombard | 24 - Drop NL04 by 0.1, Pump OFF Ohmic H-modes |
| Jul 22 2007 09:11:11:313PM | 1070720025 | Brian Labombard | 25 - Repeat with Cryopump ON Ohmic H-modes |
| Jul 22 2007 09:11:23:517PM | 1070720026 | Brian Labombard | 26 - Repeat, NL04 ~0.9, Pump ON Peak cryo pressure is 3 mtorr |
| Jul 22 2007 09:11:36:893PM | 1070720027 | Brian Labombard | 27 - Repeat, NL04 ~1.0, Pump OFF Peak cryo pressure is 41 mtorr. |
| Jul 22 2007 09:11:59:563PM | 1070720029 | Brian Labombard | 29 - Reload shot#7, NL04 ~ 0.94 DN, SSEP ~ 0, Flat NL04 program of 0.94, Ip=0.8, pump OFF Cryo pressure is 16 mtorr, B-bottom is 14 mtorr |
| Jul 22 2007 09:12:15:237PM | 1070720031 | Brian Labombard | 31 - DN, SSEP ~ 0, Flat NL04~ 0.85, Ip=0.8 pump OFF Cryo pressure is 8 mtorr, B-bottom is 8 mtorr |
| Jul 22 2007 09:12:28:567PM | 1070720033 | Brian Labombard | 33 - DN, SSEP ~ 0, Flat NL04~0.75, Ip=0.8 pump OFF Cryo pressure is 3 mtorr, B-bottom is 3 mtorr |
| Jul 22 2007 09:12:43:753PM | 1070720034 | Brian Labombard | 34 - DN, SSEP ~ 0, Flat NL04~0.75, Ip=0.8 pump ON Cryo pressure is 0.6 mtorr, B-bottom is 2 mtorr |
| Physics Operator Comments | |||
| Jul 20 2007 08:59:57:730AM | Robert Granetz | Loaded segment 2 with lower null from 1070525006 and modified for reversed field | |
| Jul 20 2007 09:13:37:120AM | 1070720001 | Robert Granetz | Shot 01 -- Plasma. Disrupted at 0.75 s. PLC setups might be from the tests yesterday rather than the requested plasma shot. Next shot: load the correct PLC setups and try again |
| Jul 20 2007 09:40:21:680AM | 1070720003 | Robert Granetz | Shot 02 -- Plasma. Good shot. 0.8 MA, 5.4 T, 0.8e20 m-2, lower null, reversed Bt. Next shot: load 1070525016 seg 3 into seg 3 (upper null) and modify for reversed field. Turn on cryopump. Increase pre-fill from 15 to 32 ms because of cryopump. |
| Jul 20 2007 09:49:53:630AM | 1070720003 | Robert Granetz | Shot 03 -- Plasma. Good shot. Upper null, reversed Bt, cryopump on. Looks like it was pumping to me. Next shot: load 1070525018 seg 3 into seg 3; modify for reversed field; Cryopump will be off, so reduce pre-fill to 16 ms. |
| Jul 20 2007 10:01:22:410AM | 1070720004 | Robert Granetz | Shot 04 -- Plasma. Good shot. Upper null, reversed Bt, no cryopump. Next shot: load 1070525024 seg 3 into seg 3; modify for reversed Bt. Increase pre-fill to 32 ms because cryopump will be on. |
| Jul 20 2007 10:13:16:030AM | 1070720005 | Robert Granetz | Shot 05 -- Plasma. Good shot. Upper null; reversed Bt; cryopump on Next shot: load 1070525026 seg 3 into seg 3; modify for reversed field; Set pre-fill at 32 ms because cryopump will be on. |
| Jul 20 2007 10:24:16:387AM | 1070720006 | Robert Granetz | Shot 06 -- Plasma. Good shot. Upper null; reversed Bt; cryopump on. Next shot: Load 1070525029 seg 4 into seg 4; modify for reversed Bt; turn on seg 4, turn off seg 3; set pre-fill at 32 ms because cryopump will be on. |
| Jul 20 2007 10:41:29:923AM | 1070720007 | Robert Granetz | Shot 07 -- Plasma. Good shot. Nearly double null; reversed Bt; cryopump on. Next shot: load 1070525031 seg 4 into seg 4; modify for reversed Bt; Pre-fill at 32 ms because cryopump will be on. |
| Jul 20 2007 10:51:43:043AM | 1070720008 | Robert Granetz | Shot 08 -- Plasma. Good shot. Lower null; reversed field; cryopump on. Next shot: load 1070601020 seg 3 into seg 3; modify for reversed Bt; turn on seg 3, turn off seg 4; Set pre-fill at 32 ms because cryopump will be on. |
| Jul 20 2007 11:11:06:770AM | 1070720009 | Robert Granetz | Shot 09 -- Plasma. Good shot. Upper null; reversed Bt; cryopump on. This was supposed to be 1.0 MA, but we actually got 0.92. This is because there was a 35 kA offset programmed into Ip (inherited from the import_segment from 1070601020.) Next shot: repeat, except zero the offset in Ip |
| Jul 20 2007 11:11:43:740AM | 1070720010 | Robert Granetz | Shot 10 -- Plasma. Good shot. upper null; reversed Bt; cryopump on. Next shot: load 1070601029 seg 4 into seg 4; modify for reversed Bt; Turn on seg 4, turn off seg 3; Set pre-fill at 32 ms because cryopump will be on. Zero out the programmed offset of 35 kA in Ip. |
| Jul 20 2007 11:32:43:903AM | 1070720011 | Robert Granetz | Shot 11 -- Plasma. Disrupted at t=1.52 s. Double null w/SSEP jog; reversed Bt; cryopump on. Not clear what caused the disruption. Might have been a molybdenum injection. Next shot: repeat, except turn on argon puff |
| Jul 20 2007 11:49:55:957AM | 1070720012 | Robert Granetz | Shot 12 -- Plasma. Good shot. Double null; reversed Bt; cryopump on; argon on. Next shot: load 1070718029 seg 3 into seg 3; turn off argon; Turn on seg 3, turn off seg 4; Set pre-fill at 16 ms because cryopump will be off. |
| Jul 20 2007 12:00:05:280PM | 1070720013 | Robert Granetz | There's a problem with a ""bit"" not working between MDS and the PLCs. We'll have to do a no-power shot to clear the problem. |
| Jul 20 2007 12:00:27:797PM | 1070720013 | Robert Granetz | Shot 13 -- No-power shot to clear a software bit problem. |
| Jul 20 2007 12:15:12:017PM | 1070720014 | Robert Granetz | Shot 14 -- Plasma. Good shot. Upper null; reversed Bt; no cryopump. This is a direct comparison to the same shot this past Wednesday. Next shot: load 1070718030 seg 3 into seg 3. Keep argon off. Set pre-fill at 32 ms because cryopump will be on. |
| Jul 20 2007 12:52:08:310PM | 1070720015 | Robert Granetz | Shot 15 -- Plasma. Good shot. Upper null; reversed Bt; cryopump on. This is a direct comparison to shot 30 on Wednesday, which didn't show much pumping. Did this one pump? Hey Brian, did this one pump? The answer is: NO, it did not pump well. This reproduces Wednesday's result. Apparently the good pumping we saw earlier today is because those plasmas were higher density. Next shot: reload shot 10 from today. Reduce nl_04 to 1.05e20 m-2. Cryopump on; argon off. |
| Jul 20 2007 01:06:07:777PM | 1070720016 | Robert Granetz | Shot 16 -- Plasma. Good shot. nl_04 went almost to 2e20 m-2. Rumors of cold ohmic H-modes and/or ITBs are circulating. Next shot: repeat w/no DPCS changes |
| Jul 20 2007 01:12:43:097PM | 1070720017 | Robert Granetz | Shot 17 -- Plasma. Good shot. Another high density shot with an ITB. Next shot: repeat, but with cryopump off. Therefore reduce pre-fill to 16 ms. |
| Jul 20 2007 01:33:02:247PM | 1070720018 | Robert Granetz | Shot 18 -- Plasma. Good shot. No ohmic H-mode nor ITB this time, so maybe the cryopump really is responsible for it on the previous two shots. Next shot: Reload shot 5 from today (upper null); decrease nl_04 to 0.8e20 m-2; Set pre-fill at 32 ms because cryopump will be on. Argon remains off. |
| Jul 20 2007 01:39:39:347PM | 1070720019 | Robert Granetz | Shot 19 -- Fizzle. No obvious reason why. Next shot: repeat, no changes |
| Jul 20 2007 02:03:08:890PM | 1070720020 | Robert Granetz | Shot 20 -- Plasma. Good shot. Upper null; reversed field; cryopump on. nl_04=0.9e20 m-2. Next shot: repeat but with cryopump off. A lithium pellet will be fired at 1.5 s. |
| Jul 20 2007 02:06:24:690PM | 1070720021 | Robert Granetz | Shot 21 -- Plasma. Good shot. Upper null; reversed Bt; cryopump off. I forgot to decrease the pre-fill, but the shot went fine anyway. Li pellet was injected at t=1.51 s. Next shot: reduce nl_04 to 0.7e20 m-2. Pre-fill at 32 ms because cryopump will be on. |
| Jul 20 2007 02:23:24:413PM | 1070720022 | Robert Granetz | Shot 22 -- Plasma. Good shot. Upper null; reversed Bt; cryopump on. Got several ohmic H-modes, which raises the density. Next shot: repeat, but with cryopump off. See whether or not we get an H-mode. Set pre-fill to 16 ms because cryopump will be off. |
| Jul 20 2007 02:42:12:793PM | 1070720023 | Robert Granetz | Shot 23 -- Plasma. Good shot. Upper null; reversed Bt; cryopump off. No H-modes. Looks like the cryopump really does enable access to ohmic H-modes. Next shot: reduce nl_04 to 0.7e20 m-2; keep cryopump off. |
| Jul 20 2007 02:51:46:447PM | 1070720024 | Robert Granetz | Shot 24 -- Plasma. Good shot. Upper null; reversed Bt; cryopump off. This shot had ohmic H-modes even without the cryopump, so we've probably made it down to a low enough density to access H-modes even with the pumping. Next shot: repeat w/cryopump on. Set pre-fill to 32 ms. |
| Jul 20 2007 03:05:47:807PM | 1070720025 | Robert Granetz | Shot 25 -- Plasma. Good shot. Upper null; reversed Bt; cryopump on. Got several ohmic H-modes. Next shot: increase nl_04 to 0.9e20 m-2; keep cryopump on. |
| Jul 20 2007 03:19:26:570PM | 1070720026 | Robert Granetz | Shot 26 -- Plasma. Good shot. Upper null; reversed Bt; cryopump on. Good pumping. Next shot: repeat w/cryopump off. Set pre-fill to 16 ms. |
| Jul 20 2007 03:47:54:093PM | 1070720027 | Robert Granetz | Shot 27 -- Plasma. Good shot. Upper null; reversed Bt; cryopump off. Very large pressure measured in the upper chamber. Next shot: reload shot 7 (double null) and set nl_04=0.8e20 m-2. Set pre-fill to 16 ms because the cryopump will be off. |
| Jul 20 2007 03:51:27:373PM | 1070720028 | Robert Granetz | Shot 28 -- Fizzle. Next shot: reduce pre-fill to 14 ms |
| Jul 20 2007 04:07:33:700PM | 1070720029 | Robert Granetz | Shot 29 -- Plasma. Good shot. Near double null; reversed Bt; cryopump off. Next shot: reduce nl_04 to 0.7e20 m-2. Cryopump off. |
| Jul 20 2007 04:18:33:257PM | 1070720030 | Robert Granetz | Shot 30 -- Fizzle. Next shot: reduce prefill another 2 ms (to 12 ms). |
| Jul 20 2007 04:32:20:993PM | 1070720031 | Robert Granetz | Shot 31 -- Plasma. Good shot. Double null; reversed Bt; cryopump off. Next shot: decrease nl_04 to 0.6e20 m-2; Keep the pump off. |
| Jul 20 2007 04:44:02:850PM | 1070720032 | Robert Granetz | Shot 32 -- Fizzle. Next shot: reduce pre-fill another 2 ms, so it will now be only 10 ms. |
| Jul 20 2007 04:57:48:943PM | 1070720032 | Robert Granetz | There may be a small N2 leak into the vessel. Vessel temperature is 14 C, and the RGA is showing about a 10-fold increase in mass 28. |
| Jul 20 2007 05:06:49:907PM | 1070720033 | Robert Granetz | Shot 33 -- Plasma. Good shot. Double null; reversed Bt; cryopump off. Next shot: repeat with cryopump on. Set pre-fill to 32 ms because the cryopump will be on. Lithium pellet will be fired at 1.5 s. |
| Jul 20 2007 05:07:17:000PM | 1070720034 | Robert Granetz | Shot 34 -- Plasma. Good shot. Double null; reversed Bt; cryopump on. A lithium pellet disrupted the plasma. End of run |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:02:08:107AM | Plasma | Ok | |
| 2 | 09:22:59:037AM | Plasma | Ok | |
| 3 | 09:39:53:837AM | Plasma | Ok | |
| 4 | 09:52:16:883AM | Plasma | Ok | |
| 5 | 10:05:29:350AM | Plasma | Ok | |
| 6 | 10:18:15:990AM | Plasma | Ok | |
| 7 | 10:30:58:787AM | Plasma | Ok | |
| 8 | 10:43:44:097AM | Plasma | Ok | |
| 9 | 10:57:10:660AM | Plasma | Ok | |
| 10 | 11:11:08:050AM | Plasma | Ok | |
| 11 | 11:23:48:613AM | Plasma | Ok | |
| 12 | 11:39:33:520AM | Plasma | Ok | |
| 13 | 12:00:27:560PM | Test | Ok | No Power shot due to state failure |
| 14 | 12:11:43:120PM | Plasma | Ok | |
| 15 | 12:24:34:073PM | Plasma | Ok | |
| 16 | 12:52:56:357PM | Plasma | Ok | |
| 17 | 01:08:56:407PM | Plasma | Ok | |
| 18 | 01:21:44:203PM | Plasma | Ok | |
| 19 | 01:34:18:530PM | Plasma | Ok | |
| 20 | 01:46:49:683PM | Plasma | Ok | |
| 21 | 02:00:07:323PM | Plasma | Ok | |
| 22 | 02:14:21:920PM | Plasma | Ok | |
| 23 | 02:29:24:577PM | Plasma | Ok | |
| 24 | 02:41:47:030PM | Plasma | Ok | |
| 25 | 02:58:11:640PM | Plasma | Ok | |
| 26 | 03:11:16:013PM | Plasma | Ok | |
| 27 | 03:32:32:330PM | Plasma | Ok | |
| 28 | 03:48:25:467PM | Plasma | Ok | |
| 29 | 04:01:33:393PM | Plasma | Ok | |
| 30 | 04:14:18:177PM | Plasma | Ok | |
| 31 | 04:26:51:457PM | Plasma | Ok | |
| 32 | 04:39:42:750PM | Plasma | Ok | |
| 33 | 04:52:11:267PM | Plasma | Ok | |
| 34 | 05:04:40:187PM | Plasma | Ok | |
| System Availability | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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