Miniproposals

Miniproposal: 162a Date Filed: 5/6/1997 Title: Volume Recombination in the Alcator C-Mod Divertor (Revised) First Author: Jim Terry Session Leader: Bruce Lipschultz (shots 1-38) Session Leader: Jim Terry (shots 1-38)

Engineering Operator Run Comment

Snow Storm/MP162A Wolfe

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Entered: Jul 7 2004 03:49:17:833PM

Author: To Be Determined

run 980116 session leader: Jim Terry/Bruce Lipschultz physop: Steve Wolfe engineering op: Frank Silva Mini-proposal 162A: "Volume Recombination in the Alcator C-Mod Divertor" The purpose of this mp was to explore the characteristics of detachment and recombination. This was addressed successfully in a number of ways: visible and VUV spectroscopy in the divertor region, divertor and Fast-scanning probes documenting depth of detachment, plasma TV imaging the divertor using D_Gamma, bolometry and divertor RGA. The major results from an initial analysis are: (1) Deep detachment found at high densities. This is evidenced by movement of the recombinaiton radiation up the divertor face to above the noses and to the x-point. This seemed clear from the TV and from the Reticon arrays and spectrometer views. (2) Strong recombination on and above the inner nose and along the outer leg. (3) Strong self-absorption of Lyman-Beta seen on shots 027, 031, 034 and 038. Strong self-absorption of Lyman-Alpha implied on shot 036. (4) shot 004 reached the highest density (nl04=2.5e20) for Ip=0.8 MA. Shots 006 and 008 were also high density. Shots 012, 16 and 17 had the best strike point control. (5) A slow detachment was achieved for shots 19-23 (023 the best example). (6) shots after 23 had 1 MA plasma current with the highest density of nl04=2.5e20 from shot 27 on. The RF power was ramped up on shots 31 through 38 with the most power (3 MW) on shot 38. This was done to reattach the outer divertor and was most successful on shot 38. There was very little heating of the core or increased radiated power leaving us with a puzzle for where the power went. (7) J. Goetz and S. Pitcher did some experiments relating to filtering the neutral power from reaching the 'Ledge' bolometers. Gas was puffed into the bolo box to attenuate the neutrals through scattering. Clear effects were seen on some channels. (8) J. Goetz was also looking at the compression of Ar into the divertor through this period. There were significant effects there as well. There was more Ar in the divertor during detachment. The details follow: shot #1: Fizzle shot #2: RF on when it should not be. nl04 ~ 2e20 increasing at .9 sec to 2.5e20. Some sort of H-mode. shot #3: clear detachment around 0.6 seconds but strike point moving. There appears also to be detachment on probe 8. shot #4: runaways early and then disruption at 1.05 seconds. No ECE because of gate valve problems. Still detaching at 0.6 seconds. shot #5: fizzle shot #6: disruption at 0.95 seconds. Still having problems with strike point. shot #7: fizzle shot #8: disrupts at 1.2 seconds. Detaches around o.68. nl04 slightly lower at 2.2e20. shot #9: early disruption due to bricks. shot #10: fizzle shot #11: strike point on the floor until about 0.8 seconds. disruption at 1.16 seconds. shot #12: detached before 0.6 seconds and disrupts at 1.07. STRKPSI control used so that strike point constant on probe 5. J. Goetz/CSP have tried puffing into the Ledge Bolo to effectively filter the neutrals out of the signal. This had a different effect when pufed during the full detachment then earlier in the shot. One possible explanation is that the distribution of neutrals in the divertor is changing during the shot. shot #13: dud shot #14: fizzle shot #15: brick killed plasma shot #16: Got FSP data at 0.9 seconds. Disrupted at 1.05 seconds. shot #17: lasted to 1.25 seconds with sharkfin. No FSP. shot #18: fizzle shot #19: several injections. Detaches at .78 seconds. Slower density ramp + final density of nl04=1.6e20. shot #20: brick at 0.4 seconds -> disruption. shot #21: Detaches at 0.6 seconds. Slow detachment in terms of changes in bolos and Balmer radiation. 28 ms Ar pulse. shot #22: Detachment starts at 0.6 but doesn't reach probe 7 till 0.9 seconds. Separatrix position around probe 4. shot #23: 0.8 MA nl04=1.5e20., Detached. shot #24: 1 MA. nl04=1.5e20. No detachment. Sharkfin at 1.36 seconds. shot #25: 1 MA. nlo04=2.2e20. detachment (.84 - .95 sec). Disrupts at 1.37 sec. shot #26: fizzle shot #27: 1 MA, nl04=2.53e20. detachment earlier starting at 0.68 sec. Disrupts at 1.38 seconds. shot #28: shot #29: disrupts at 0.6 seconds, brick? shot #30: fizzle shot #31: RF on in steps starting at 0.9 seconds. 3 steps, each 90 ms seconds long stepping up to 0.8 MW. It starts to come out of detachment. shot #32: RF on in steps starting at 0.9 seconds. 3 steps, each 90 ms seconds long stepping up to 1.5 MW. It starts to come out of detachment. shot #33: fizzle shot #34: RF on in steps starting at 0.9 seconds. 3 steps, each 90 ms seconds long stepping up to 2.0 MW. It starts to come out of detachment. shot #35: fizzle shot #36: Again with even more RF power (2.5 MW). It is clear that the power is not really getting into the main plasma. Very little change in the core Te and stored energy. Some of the divertor plate is attached (Death ray). shot #37: fizzle shot #38: 3 MW of RF - looks like almost fully attached. Still have death ray.

Physics Operator Summaries

Entered: Jul 7 2004 04:36:58:800PM

Author: To Be Determined

Physop Summary for Friday 980116 MP#162A "Volume Recombination in the Alcator C-Mod Divertor" SL: Terry, Asst. SL:Blip PO: wolfe EO: Silva, Cochran Setup: ----- Discharge clean for 2 hrs. in D_2 prior to the run Power systems as on 980106030, EXCEPT TF current limit=183kA TF under hybrid control B-top 6psi D2 Hybrid Enable K-side 30psi D2 Hybrid Enable J-bot 30psi D2 Hybrid Enable B-side Lower 2psi Ar Not enabled Enable ECE gate valve. Others as requested. Run plan -------- The first half or so is planned to be ohmic density ramps, then RF in small steps to re-attach the divertor. Start from 980106030, an ohmic density ramp to high density, but increase gain on ZXL to try to hold strikepoint more constant, particularly before 1sec. If the supply can handle it, program ZXL or STRKPSI to maintain the strikepoint at probe 3 (.622,-.524). Otherwise, try a shorter ramp, stopping at a lower density, as on 980106033. Also, increase the TF to 5.7Tesla to avoid ECE cutoff. If we get the density rise (to NL_04=2.6e20) from this programming and if it detaches deeply as 980106030 does, then repeat the shot for ~8 shots while the McPherson scans in space. After the 1st 4 shots JT will need a cell access to quickly switch the "McPherson fiber" from the CHROMEX to the filtered (6563 A) PMT. Then take the same shot at 1 MA instead of 0.8 MA. Use the next ~6 shots to slow down the density rise and the detachment by changing the gas programming. (Ip will be either 0.8 or 1.0 depending on results.) Use the rest of the run to step up the RF during the discharge (1 step every 0.09 s) until it reattaches the divertor. Investigate the recombination at each power step. Diagnostic setup: Divertor TV - H_gamma filter Chromex bin view 1 McP 2 Ktop_4 3 Ktop_5 ... 8 Ktop_10 9 Abot_8 10 Abot_10 ... 15 Abot_16 16 Kside_0 McPherson Visible view initial with no filter to Chromex FSP in once at .5 s (attached plasma) and again at 1.0 s(detached plasma presumably) Results: -------- We were having a snowstorm, but a full crew came in. Most of the goals were accomplished, but it was a frustrating run with lots of disruptions and fizzles, as well as two unexplained duds. We ended up with 24 plasmas out of 38 attempts. Shot 1 fizzled, and after a small EF4 tweak shot 2 ran, but with 2MW of RF on for most of the shot, which went into H-mode and looked a lot like yesterday's shots (except the current was flat at 800kA). It turns out that nobody had turned the RF off in the tree and the transmitters were on for when we would want them later. The first shot actually in the program was #3, which disrupted at 1.33sec, early in ramp-down. The ZXL control was fair, but the strikepoint was still sweeping up the plate. Shots 4-8 were attempts to control the strikepoint by playing with the ZXL program and gains. Meanwhile, JT was doing his initial spectrometer scans. Shot 9-11 we tried programming RXL as well; the sequence included an early disruption and a DUD. When we finally got the shot to go, it started with the x-point on the floor and then swept part way up the plate. On shot 12 I started exercising the STRKPSI control, which proved more successful at keeping the strikepoint in a narrow range, but resulted in more motion of the x-point, as expected. The strikepoint ended up on probe 5 instead of probe 3, but stayed pretty well put from .6sec to the disruption. Shots 12-16 were done with strkpsi control; all those that went disrupted early. After #16, JT went into the cell to switch his fiber. Shot 17-23 were run with clearin relaxed to -.012, and had a scan of density ramps. These mostly lasted into rampdown, but not very far down. There was an attempt to move the strikepoint down the plate by programming the strkpsi feedback to -.002, but we ended up back on the floor early in the shot, so returned to programming it for nominal 0.0 (at the location of probe 3). Shot 24-27 were at 1MA, with the final density raised progressively to nl4=2.5e20. Shot 29-38 were !MA shots with the same density ramp as 27 (final level 2.5e20), but with stepped RF power to re-attach the divertor. It ultimately took 3MW to re-attach. During this sequence, I turned on integral gain on STRKPSI, which seemed to do a good job of fixing the strike, although still higher than desired. See the PHYSICS_OPERATOR entries in the logbook for a detailed description of the gains and tweaks. The STRKPSI control seems to still work, with a combination of proportional and integral gain (8 and 5 respectively), although there seems to be some offset which makes the actual strike come out higher than requested with near zero error. The high density shots were vertically unstable (n/nc=1.3) largely due to high li. The OH2 oscillation problem also showed up. The EFC voltage was raised to from 700 to 800V on shot 7 to try to improve vertical stability. It may have made a marginal difference. The voltage signal from EFC-B TMX supply looks like it isn't working, but the chopper static voltage is higher than the sum of A and C, so this is probably an instrumentation problem. We had a lot of fizzles, and two duds (#10 and #13). I chased the startup all over the place (fields and gas) without success. After each dud I increased the puff, then dropped it back later; probably should have left it alone and it would have been ok anyway. I ended up with 14msec puff. The fields looked reasonable and if I just left it alone, the next shot would go just fine. I suspect either a subtle cooling effect or a pump-out effect. Fizzles typically had a lump of CII emission instead of a clean burnout. There was a computer problem before the start of the run that Josh fixed from home, apparently due to the archive server being hung. The last two shots also had computer problems; the engineering comment had been entered, but for some reason didn't get loaded to the logbook, causing the check_shot task to loop and hang. Aside from that, computer systems worked well. Power systems worked well, except for two breaker pulls after disruption-induced crowbars (OH2L and OH1). The OH2 oscillation problem is still there, and contributed to the disruption on shot 16. Cooling was ready before we were most of the day. Scorecard --------- tests 0 duds 2 fizzles 12 plasmas 24 ------- -- shots 38

Session Leader Comments
Jan 16 1998 09:15:36:820AM	980116002	Bruce Lipschultz	shot #2: RF on when it should not be. nl04 ~ 2e20 increasing at .9 sec to 2.5e20. Some sort of H-mode.
Jan 16 1998 09:31:28:290AM	980116003	Bruce Lipschultz	shot #3: clear detachment around 0.6 seconds but strike point moving. There appears also to be detachment on probe 8.
Jan 16 1998 09:45:28:820AM	980116004	Bruce Lipschultz	shot #4: runaways early and then disruption at 1.05 seconds. No ECE because of gate valve problems. Still detaching at 0.6 seconds.
Jan 16 1998 10:20:03:880AM	980116006	Bruce Lipschultz	shot #6: disruption at 0.95 seconds. Still having problems with strike point.
Jan 16 1998 10:53:40:510AM	980116008	Bruce Lipschultz	shot #8: disrupts at 1.2 seconds. Detaches around o.68. nl04 slightly lower at 2.2e20.
Jan 16 1998 11:34:33:420AM	980116011	Bruce Lipschultz	shot #11: strike point on the floor until about 0.8 seconds. disruption at 1.16 seconds.
Jan 16 1998 11:54:59:490AM	980116012	Bruce Lipschultz	shot #12: detached before 0.6 seconds and disrupts at 1.07. STRKPSI control used so that strike point constant on probe 5.
Jan 16 1998 05:26:22:810PM	980116016	Bruce Lipschultz	shot #16: Got FSP data at 0.9 seconds. Disrupted at 1.05 seconds.
Jan 16 1998 12:59:50:470PM	980116017	Bruce Lipschultz	shot #17: lasted to 1.25 seconds with sharkfin. No FSP.
Jan 16 1998 01:27:53:620PM	980116019	Bruce Lipschultz	shot #19: several injections. Detaches at .78 seconds. Slower density ramp + final density of nl04=1.6e20.
Jan 16 1998 01:56:17:940PM	980116021	Bruce Lipschultz	shot #21: Detaches at 0.6 seconds. Slow detachment in terms of changes in bolos and Balmer radiation. 28 ms Ar pulse.
Jan 16 1998 02:23:25:460PM	980116022	Bruce Lipschultz	shot #22: Detachment starts at 0.6 but doesn't reach probe 7 till 0.9 seconds. Separatrix position around probe 4.
Jan 16 1998 02:32:47:790PM	980116023	Bruce Lipschultz	shot #23: 1 MA. nl04=1.5e20. No detachment.
Jan 16 1998 05:25:30:570PM	980116024	Bruce Lipschultz	shot #24: 1 MA. nl04=1.5e20. No detachment. Sharkfin at 1.36 seconds.
Jan 16 1998 05:24:56:900PM	980116025	Bruce Lipschultz	shot #25: 1 MA. nlo04=2.2e20. detachment (.84 - .95 sec). Disrupts at 1.37 sec.
Jan 16 1998 05:24:18:460PM	980116026	Bruce Lipschultz	shot #26: Fizzle
Jan 16 1998 05:23:47:440PM	980116027	Bruce Lipschultz	shot #27: 1 MA, nl04=2.53e20. detachment earlier starting at 0.68 sec. Disrupts at 1.38 seconds.
Jan 16 1998 03:55:46:380PM	980116031	Bruce Lipschultz	shot #31: RF on in steps starting at 0.9 seconds. 3 steps, each 90 ms seconds long stepping up to 0.8 MW. It starts to come out of detachment.
Jan 16 1998 04:06:56:580PM	980116032	Bruce Lipschultz	shot #32: RF on in steps starting at 0.9 seconds. 3 steps, each 90 ms seconds long stepping up to 1.5 MW. It starts to come out of detachment.
Jan 16 1998 04:21:47:410PM	980116034	Bruce Lipschultz	shot #34: RF on in steps starting at 0.9 seconds. 3 steps, each 90 ms seconds long stepping up to 2.0 MW. It starts to come out of detachment.
Jan 16 1998 04:47:37:170PM	980116036	Bruce Lipschultz	shot #36: Again with even more RF power (2.5 MW). It is clear that the power is not really getting into the main plasma. Very little change in the core Te and stored energy.
Jan 16 1998 05:19:40:120PM	980116038	Bruce Lipschultz	shot #38: 3 MW of RF - looks like almost fully attached. Still have death ray.

Physics Operator Comments
Jan 15 1998 12:29:01:970PM		Steve Wolfe	Working on setting up for JT's run tomorrow. He wants high density ohmic with a density ramp like on 980106030, but with out the upward migration of the strikepoint and x-point. This will be a problem, because EF1L is close to its voltage rail. I'll need more gain on ZXL if we do it that way. Import seg2 from 980106030 into current model (around shot 980115003?). I'm going to need more ZXL gain. Copy wire 6->9 . Set up ZXL9 with g=4 for t>.30 Recall algorithm for both wire 6 & 9 ZXL. set factor to 5e-5 (was 3e-5). set up strkpsi control , but don't turn on gain. Use probe 3 location RSOUT=.622,ZSOUT=-.524. set strkpsi value =0. so we can look at error on phys_aout. save in pcs$wolfe shot 980116999.
Jan 15 1998 02:15:56:440PM		Steve Wolfe	Increase TF current to -157000 in both seg1 and seg2. When I do a build_all, I get a warning that P_03 in segment 1 has been renamed since it was last drawn. It hasn't, so there may be a bug somewhere. I tried touching a point in ZCUR3, but it still gave the message.
Jan 15 1998 05:07:10:750PM		Steve Wolfe	Run is over. Load from my 980116999. Do a Load/Clean into model I'm still getting that rename warning. I don't understand that; the segment 1 was taken from an existing startup in the model.
Jan 15 1998 05:14:24:060PM		Steve Wolfe	Still investigating this re-name warning on P_03. Quit PCS and get back in. Try a build-all -- still does it! Do an import_segment from today's first shot 980115001 Do another build_all: OK, no more warnings. Load/Clean this one. Just to be sure, save it in my area as 980116999, superceding the other one. OOps, I forgot to change the TF trace in the new SEgment 1. Now load/clean and re-do the save as again. OK, now I'm set for tomorrow.
Jan 16 1998 07:24:31:150AM		Steve Wolfe	Some problem starting cycle this morning. JAS fixed it from home. Doing coldstart 07:15 All ok.
Jan 16 1998 08:49:23:020AM	980116001	Steve Wolfe	Shot 1: Setup for ohmic density ramp, using two ZXL wires with G6=8.2,G9=4. NOTE: Somehow the original shot had not had the gain on wire 9 changed; it was still a copy of wire 6. I reset it and reloaded at 07:51:11.00. fizzle : long hesitation. Bz a bit negative early, comes in slow. Note: TRAQ1 data corrupted, Ian's flux things are crazy.
Jan 16 1998 09:11:51:470AM	980116002	Steve Wolfe	Shot2: IC_EF4 from -1345 -> -1330 plasma. still a hesitation early. The RF was on at 2MW level, like yesterday!@&)&)& H-mode very similar to yesterday. Strike points are on the floor until H-L, then jumps up. Don't mess with equilibrium until we get an ohmic shot.
Jan 16 1998 09:25:39:560AM	980116003	Steve Wolfe	Shot 3: Try a repeat with no RF. plasma. Disrupts at 1.33sec. Gets to nl4=2.6. ZXL error is positive, but smaller than on shot 980106030. Strkpsi still moves up the plate, error reaches 4000 at 1.2sec.
Jan 16 1998 09:49:33:730AM	980116004	Steve Wolfe	Shot 4: Increase ZXL gain on wire 9 to 9.0 Runaways and lots of them, disrupted at 1.05. Got to density eventually.
Jan 16 1998 09:56:33:270AM	980116005	Steve Wolfe	SHot 5: INcrease pre-puff to 19msec, raise first PG3 point to 100V. Turn on Argon (20msec @2psi) per Blip Ramp ZXL down from -1.5cm to -2cm from 0.6 to 1.2sec IC_EF4 to -1320. flattop nl4 at 2.1e20 to try to avoid fin (per JT) fizzle. Went too far on EF4? Too many startup changes. Br too positive, Also Bz too positive.
Jan 16 1998 10:20:31:840AM	980116006	Steve Wolfe	SHot 6: Turn on Argon (20msec @2psi) per Blip Ramp ZXL down from -1.5cm to -2cm from 0.6 to 1.2sec IC_EF4 at -1320. Br offset from .006 -> .0055 plasma disrupts at 0.95, strike still sweeping up the plate, ZXL according to EFIT is constant, according to Phys_aout it is on track.
Jan 16 1998 12:24:01:790PM	980116007	Steve Wolfe	Shot 7: Drop PG3 maintenance level from 100V to 50V. Turn off Argon. JR claims it wasn't going in. Raise chopper voltage to 800V fizzle.
Jan 16 1998 10:52:00:050AM	980116008	Steve Wolfe	Shot 8: Drop pre-puff to 14msec plasma disrupts at 1.18, still has a growing vertical instability Frank pointed out on shot 6 7 that the voltage didn't seem to go up on the chopper, and TMX B seems to be dead. Static voltage seems to be low, not much higher than before I changed it. Apparently it has been this way since at least 971218
Jan 16 1998 10:59:32:520AM	980116009	Steve Wolfe	shot 9: Move RXL in from .006 to -.006 Early disruption at .4sec. looks like an injection.
Jan 16 1998 11:12:00:590AM	980116010	Steve Wolfe	shot 10: Increase seg2 early pg3 from 50 to 85-90, try to get the early marfe back. dud!? Fields don't look bad. gas puff is there. What was wrong?
Jan 16 1998 11:27:08:780AM	980116011	Steve Wolfe	shot 11: Increase seg2 early pg3 from 50 to 85-90, try to get the early marfe back. Increase gas puff to 16msec plasma disrupts at 1.18, still has a growing vertical instability. Strike is on the floor early, then sweeps up. Next shot try STRKPSI control
Jan 16 1998 11:54:30:960AM	980116012	Steve Wolfe	shot 12: RXL reloaded from shot 8 STRKSPI on at 0.6 with gain of 8 ZXL G6=2@ 0.6, G9=0.0 Turn off pg3 voltage program at 1.0 Increase early nl4 program to 1.0 at .3 sec Disrupted a bit earlier 1.05, Seems to have held th estrikepoint pretty well. A bit higher than they want, but at least constant. Next shot, repeat for Brian to probe, then let JT in the cell.
Jan 16 1998 12:05:50:580PM	980116013	Steve Wolfe	shot 13: Repeat for FSP, one probe at 0.9sec Another dud! What the hell is going on?
Jan 16 1998 12:13:57:620PM	980116014	Steve Wolfe	shot 14: pre-puff to 18msec, IC_EF4 to -1330 from -1320 Repeat of 12 for FSP, one probe at 0.9sec fizzle.
Jan 16 1998 12:30:59:450PM	980116015	Steve Wolfe	shot 15: pre-puff to 16msec, leave EF4 at -1330. Br is all over the map on these shots; on 14 it was negative. I can't keep up with that. Bz may be coming in too fast as well. Early disruption. Brick at .3sec Startup looked good, but the Bz was more positive than before I did the EF4-> -1330?
Jan 16 1998 12:42:32:280PM	980116016	Steve Wolfe	shot 16: Repeat plasma disrupts at 1sec, OH2L crowbars and pulls breaker. Big vertical instability growing from 0.9sec. This one looks like the OH2L went a bit wild. Pause for JT to get a cell access and Bill to check out the OH2l. Spencer is doing a couple of D2 gas puff tests.
Jan 16 1998 12:57:33:220PM	980116017	Steve Wolfe	shot 17: Back off on CLEARIN from -.008 to -.012 plasma disrupts at 1.25 sec, just into rampdown. Still vertically unstable, but it makes it longer. Next shot, slow down trhe density ramp.
Jan 16 1998 01:06:58:120PM	980116018	Steve Wolfe	shot 18: NL4 to 1.6 at 1sec. Argon back on for this shot. fizzle. CII .005, bd at 5.4msec, mflux says early bz is slightly low? Br is slightly negative again. Just blame it on the disruption and go again.
Jan 16 1998 01:19:33:630PM	980116019	Steve Wolfe	shot 19: NL4 to 1.6 at 1sec. Argon to 25msec @2psi. No startup changes! Plasma to 1.35sec, got to 1.7 or 1.8 on nl4 detachment at .787 ? strikepoint looks constant. Lots of little injections.
Jan 16 1998 01:35:55:780PM	980116020	Steve Wolfe	shot 20: Argon to 28msec. Strikepoint to -.002. NL4 to 1.5e20, increase early nl4 to 1.0 at .4sec Disrupts at .4, OH1 crowbars. Brick!
Jan 16 1998 01:51:38:570PM	980116021	Steve Wolfe	shot 21: Increase PG3 between .3 and .5 plasma disrupts at 1.27 sec. x-point moves from floor to above the target.
Jan 16 1998 02:02:36:540PM	980116022	Steve Wolfe	shot 22: Drop maintenance PG3 to 30V. Jbot off. Program NL4 from 1.2 to 1.5 over .4 to 1.0 STRKPSI back to 0. Ar up to 31 msec (from 28). fizzle. bz may be coming in a bit too fast.
Jan 16 1998 02:16:37:520PM	980116023	Steve Wolfe	shot 23: RCUR offset from 6300 to 5800. Drop maintenance PG3 to 30V. Jbot off. Program NL4 from 1.2 to 1.5 over .4 to 1.0 STRKPSI back to 0. Ar up to 31 msec (from 28). plasma disrupts at 1.35sec, density ramp sort of ok, except for an injection at about .5 Bite out of the current at .22 from an earlier injection.
Jan 16 1998 02:26:47:660PM	980116024	Steve Wolfe	shot 24: Raise current to 1MA, density ramp from 1.2 to 2.0 maintenance PG3 to 50V. Jbot still off. plasma to 1.64, almost disrupts at 1.3 or so. Only got 1.5e20 at 1sec OOps didn't change the density program. SORRY ABOUT THAT.
Jan 16 1998 02:41:39:540PM	980116025	Steve Wolfe	shot 25: This time, program final nl4 to 2.0. Also add back jbot from .5 to 1sec at 100V plasma to 1.35sec, density looks good. It detaches ok.
Jan 16 1998 02:47:03:190PM	980116026	Steve Wolfe	shot 26: This time, program final nl4 to 2.5. fizzle. So much for the RCUR tweak.
Jan 16 1998 03:03:54:070PM	980116027	Steve Wolfe	shot 27: Repeat. program final nl4 to 2.5. plasma to 1.35 sec, density to 2.5. JT seems happy. Next shot RF
Jan 16 1998 03:07:01:230PM	980116028	Steve Wolfe	shot 28: Repeat with RF steps fizzle.
Jan 16 1998 03:19:14:440PM	980116029	Steve Wolfe	shot 29: Turn on strkpsi integral gain at .7 sec, gain=5. ; turn off both gains at 1.2 (not 1.25) Otherwise, a repeat with RF steps Disrupts early .61sec. Brick?
Jan 16 1998 03:24:17:600PM	980116030	Steve Wolfe	shot 30: Try again Turn on strkpsi integral gain at .7 sec, gain=5. ; turn off both gains at 1.2 (not 1.25) Otherwise, a repeat with RF steps fizzle.
Jan 16 1998 03:39:57:820PM	980116031	Steve Wolfe	shot 31: Try again with prepuff down to 14msec Turn on strkpsi integral gain at .7 sec, gain=5. ; turn off both gains at 1.2 (not 1.25) Otherwise, a repeat with RF steps Finally, a plasma to 1.4sec That one finned at the end. Got only one transmitter, three steps of about 250kW each. phys_aout thinks the strkpoint is well controlled; so does EFIT. Doesn't re-attach, needs more power
Jan 16 1998 03:55:00:870PM	980116032	Steve Wolfe	shot 32: Do it again, trying for the other RF transmitter. plasma to 1.45sec, RF in 3 steps to 1.5MW Didn't completely reattach. Ask for more RF
Jan 16 1998 04:08:00:010PM	980116033	Steve Wolfe	shot 33: Repeat with more RF power. fizzle. late bd, gets a CII step at 13msec,.
Jan 16 1998 04:18:02:720PM	980116034	Steve Wolfe	shot 34: Try again with more RF power. plasma to 1.45sec, RF got to 2MW slight hesitation at 15msec, small increase in CII at that time. Br slightly positive this time.
Jan 16 1998 04:25:15:450PM	980116035	Steve Wolfe	shot 35: Increase Ar to 35msec (from 31) another fizzle. I'm going to try an OH voltage tweak. I hope it's the right way.
Jan 16 1998 04:39:56:600PM	980116036	Steve Wolfe	shot 36: Increase V_OH1(.005) from 101 to 151 and V_OH2(.003 and .007) from 0 to 10V plasma to 1.4sec, RF to 2.5MW. Still not re-attaching. Add another 500kW.
Jan 16 1998 04:45:50:900PM	980116037	Steve Wolfe	shot 37: Add another .5MW to the RF steps. Pray for a plasma. fizzle. Pray harder next time.
Jan 16 1998 05:10:01:080PM	980116038	Steve Wolfe	shot 38: Add another .5MW to the RF steps. There was a delay for the computer before taking the shot. Action Monitor reported "no node" for all the CAMAC actions, but Josh said it was ok to go. plasma to 1.4sec, Prf =3MW. It reattached.

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	08:41:43:630AM	Plasma	Ok	no faults
2	08:52:22:760AM	Plasma	Ok	no faults plasma
3	09:17:04:190AM	Plasma	Ok	no faults plasma
4	09:29:37:440AM	Plasma	Ok	no faults plasma
5	09:51:38:650AM	Plasma	Ok	no faults
6	10:01:20:740AM	Plasma	Ok	no faults plasma
7	10:22:47:780AM	Plasma	Ok	no faults
8	10:34:39:370AM	Plasma	Ok	no faults plasma
9	10:52:38:030AM	Plasma	Ok	no faults
10	11:04:35:820AM	Plasma	Ok	no faults
11	11:15:17:970AM	Plasma	Ok	no faults
12	11:41:11:040AM	Plasma	Ok	no faults plasma
13	12:01:11:150PM	Plasma	Ok	no faults
14	12:09:36:330PM	Plasma	Ok	no faults
15	12:20:14:240PM	Plasma	Ok
16	12:30:51:120PM	Plasma	Ok	oh2 lower comm fault ? caused by disruption?
17	12:49:13:030PM	Plasma	Ok	no faults
18	12:59:55:530PM	Plasma	Ok	no faults
19	01:12:01:110PM	Plasma	Ok
20	01:28:21:060PM	Plasma	Ok
21	01:39:43:040PM	Plasma	Ok
22	01:58:20:480PM	Plasma	Ok
23	02:08:13:770PM	Plasma	Ok
24	02:21:27:860PM	Plasma	Ok
25	02:32:54:770PM	Plasma	Ok
26	02:45:25:490PM	Plasma	Ok
27	02:54:00:130PM	Plasma	Ok
28	03:05:29:360PM	Plasma	Ok
29	03:13:32:790PM	Plasma	Ok
30	03:22:56:500PM	Plasma	Ok
31	03:32:23:240PM	Plasma	Ok
32	03:48:51:140PM	Plasma	Ok
33	04:04:32:570PM	Plasma	Ok
34	04:12:27:540PM	Plasma	Ok
35	04:23:07:400PM	Plasma	Ok
36	04:33:05:420PM	Plasma	Ok
37	04:44:08:820PM	Plasma	Ok	OK
38	04:57:12:040PM	Plasma	Ok	OK