| Miniproposals | ||||||||||
|
| Operators | |
| Session leader(s): | Bruce Lipschultz |
| Physics operator(s): | Steve Wolfe |
| Engineering operator(s): | Andy Pfeiffer,Bill Parkin,Sam Pierson |
| Engineering Operator Run Comment |
| MP#440 Boronization erosion SL: Blip and/or Marmar PO: wolfe |
| Session Leader Plans |
| Entered: Nov 29 2005 04:00:22:710PM |
| Author: Bruce Lipschultz |
| MP440
'Erosion of boronization under different conditions' SL - B. Lipschultz Toroidal Field: 5.3 Tesla (normal direction) ramping down to 4.25T for Ohmic H-modes Plasma Current: 1.2 MA (normal direction) Working Gas Species: D2 Density: NL04 ~ 1.0 x 1020 m-2 Equilibrium configuration: start from 1051121015 RF Power, pulse length, phasing: none Impurity gas injection - no Ar or Ne Pellet Injection (species): none Impurity blow-off injection: none Diagnostic Neutral Beam: not required Special gas puffing: Non-axisymmetric Coils (Connections, Current); compensation if needed to avoid locked-modes Run plan a) - 2-4 shots with Ohmic H-modes to develop them and determine the proper field to ramp down to. b) ECDC boronization w/resonance at R=90 cm (field sweep range 10 cm total) for 20 minutes (if using 10% diborane). The RF should not be pulsed (100% duty cycle). Follow this with as many shots as needed to evaluate effect and wear it off. c) Step resonance location inward in major radius to locations at 80, 75, 70, 65, 60 cm. After each boronization evaluate the effect on Mo source rates, IR camera images, Mo levels in core and rise with H-modes. d) If there is a minimum return to it and reevaluate that spot. |
| Physics Operators Plans |
| Entered: Nov 29 2005 03:30:27:943PM |
| Author: Steve Wolfe |
Physop plan and Engineering setup for Wed. Nov 30, 2005 MP#440 Boronization erosion SL: Blip and/or Marmar PO: wolfe We will use between-shot boronization during this run. We should start the day with the diborane bottle closed, until we get our target plasma established. Other pre-boronization setup (closing shutters, etc.) should be done before the start of the run. ******* After the diborane bottle is opened, the cell and power room will be off-limits, except for SCBA equipped personnel. Overnight boronization (parameters to be specified) will begin as soon as possible after conclusion of the run. There will be no access until the diborane bottle is closed on Thursday morning. ********** NO OVERNIGHT ECDC, just 60C bake ECDC in D2 for two hours in the morning, finishing at least 1 hour before the start of the run. Power system setup as on 1051121015 Gas setup: fill B-Top with 6 psi D2 Hybrid enabled (PG4) leave B-side lower pumped out (NO Ar or Neon today) and Hybrid DISABLED leave B-side upper as is Hybrid DISABLED (PG2) fill B-main with 40 psi D2 Hybrid enabled (PG3) fill NINJA with 10 psi D2 Leave DISABLED Enable ECE, VUV and Z-bolo shutters assuming no vacuum problems Do not enable DNB gate valve at the beginning of the day. We will want both TMP#1 and TMP#2 gate valves open for pulses and boronization. NO ICRF for this run. Plan: ------ See SL_PLAN for more details, rationale. Load 1051121015 (1.2MA, Bt ramping down to 4.2T) ohmic H-mode shot. 1) After some tune-up shots, set up for initial boronization: Rmin/Rmax/Rdwell = 85/95/90 for 20 minutes, 100% duty factor 2) Evaluate, taking as many shots as required for any boronization effect to wear off. 3) Boronize again, moving center/dwell location in succession to 80, 75, 70, 65, and 60 cm. Depending on results we may alter this sequence and/or skip some points. 4) If an optimum is found, go back to that condition and evaluate again. 5) Finish run at or around 17:00, set up for overnight (full boronization). |
| Session Leader Summaries |
| Entered: Dec 1 2005 05:38:35:797PM |
| Author: Bruce Lipschultz |
| MP# 440
'Erosion of boronization under different conditions' SL - B. Lipschultz Generally an interesting run. Main points: - The boronization effect lasted many shots. The degradation, as measurered by the dPrad/dt during the first several H-modes of each shot, decreased slowly from shot to shot - not 1 shot as seen for the RF-heated H-modes. If we integrate the Ohmic input power over these shots we are typically putting 2.7 MJ into the plasma and ultimately the PFC surfaces. This should be compared to a simple case from 1050705005 where, including the RF power, the input energy was 3.3 MJ. This implies that the erosion seen in high power RF-heated H-modes is due to the RF, through such processes as RF-heating of edge ions/electrons, sheath rectification, ion orbit losses. - There were slight differences in the boronization location effect on dprad/dt initally in the range of 5 kW/s. Comparing the 90 cm (2-4 kW/s) centered boronization to that at 80 cm (like 2 kW/s),we found that that the dprad/dt was lower for the 80 cm boronization and lower still for the 70 cm. Shot 22 was the best as it did not have the injections following the boronization (shot 21 was first) which resulted in long H-modes with steady H-factors of 1.4. dPrad/dt was very low - 0.9 kW/s. There is of course the possibility that the enhancements we observed as we shifted the boronization resonance inward were all due to a buildup of boron. - Mo I radiation from a number of surfaces was monitored (Inner wall, Outer divertor cover plate - tile 81, and K-limiter). In all three boronization cases the Mo I signal during the startup phase (first 300 ms) was affected by the boronization. The effect got bigger on all three measurement locations as the resonance went from 90 to 80 to 70 cm. It also lasted longer in the sense of recovering to pre-boronized values: 1 shot for the 70 cm boronizatio, 2 shots for the 80 cm boronization, and still low after three shots for the 70 cm boronization. - In all shots the dprad/dt was lower for each successive H-mode. At first glance this would seem to indicate that we were getting less impurities in the plasma. - As usual we were getting many more impurity injections following a boronization. Could this be unipolar arcs or some other process? - Even as the dprad/dt dropped we did not achieve better stored energy or H-factors. We seemed to hit a limit. I don't have any idea why. It does not seem to be an impurity issue. But further examination of trajectories in H vs Prad/Ptot space may be illuminating. Due to a number of problems (PLCs, ECDC toroidal field supply....) we did not get as many shots as we wanted - thus not completing the mp. It may be that the best spot for boronization under Ohmic conditions is farther in in major radius. When we get the 20% diborane.... |
| Physics Operator Summaries |
| Entered: Nov 30 2005 06:00:42:607PM |
| Author: Steve Wolfe |
Not unexpectedly, this between-shot boronization experiment made for a difficult run. We ended up getting a bit less than half of the conditions listed in the plan. We did three "20 minute" between-shot boronizations, at center radii of 90, 80, and 70cm. Each ended up costing a bit over an hour, due to various difficulties with power supplies, PLC logic, etc. We also lost some time for a couple of power room SCBA accesses, and one cell access to re-align the TCI. We had a total of 22 plasma attempts, and only 13 full plasmas of any use to the experiment. The first shot was a dud (pressure too low). After a successful shot#2 we extended the flattop to 1.5sec for shot#3. This shot ramped all the way down. Some of the later shots disrupted in rampdown, and I tried some tweaks to keep the EF2's from going to zero in rampdown. However, when I finally succeeded in keeping the EF2's on, shot#20 disrupted at about the same time 1.75sec anyway. The new start-up put up by Ian yesterday was helpful, but we still ended up having to chase the pre-puff level after boronizations, and no reproducible prescription was found. After the first boronization, dropping the pg4 puff from 29 to 12msec was successful (shot 4), but going all the way back to 29msec for the next shot produced a fizzle from too high a puff. Another fizzle a couple of shots later may have been due to a field error, and I took a 10A tweak on EF4 as well as a small gas tweak. After the second boronization, 12 msec on pg4 was apparently too little, and we got another fizzle on shot 11. Also, the TCI alignment went bad around shots 10-12, and we tried changing to NL_ZMETER feedback on #12 rather than take the delay for a SCBA cell access. This worked reasonably for two shots, but then we got two early disruptions, around .5-.6 sec, which seemed to be associated with low gas puffs early in seg2 and very high Te followed by internal disruptions. After the disruption on 15 it was necessary to do a power room entry to reset a power supply anyway, so we decided to go ahead and re-align the TCI and put back the NL_04 feedback. Shot#16 was a dud, despite fields that looked good and pressure that had worked earlier. Then shot #17 resulted in another early disruption that looked very similar to 14 and 15, despite having gone back to NL04 feedback. I added a pg3 gas program early in seg2, and also made a change to the clearin program before 0.5sec, since there was just a hint of a vertical problem. For whatever reason the subsequent shots did not have early disruptions. Shot#19, following the last "20 minute" boronization, fizzled at a pre-puff of 16msec, with indications of too low pressure. The next three shots ran at pg4 of 25 and 27msec. See the SL_SUMMARY for the official evaluation of the H-modes and boronization. The peak stored energy was affected only slightly by any of the boronizations, but the rate of rise of the radiation was noticebly improved. The best case in terms of H-mode duration (or equivalently decreased rad rate) was the last location, 65/70/75. The second shot after this one (#21) seemed better than #20. The effect of boronization clearly was not gone after a single shot, in contrast to the RF case reported in Aug, Sept. In fact, five shots after the first boronization there was still a clear benefit, relative to the pre-boronized shots 2 & 3. We must therefore be careful of over-interpreting the apparent superiority of the 70cm location, since this might have still been inheriting some of the benefits of the earlier treatments. Problems contributing to delays in the second and third boronizations: a) The second boronization started ok, but the PEI tripped out and a cryptic error "TRANS FAULT" appeared on the PLC screen. This was at first erroneously interpreted as indicating a magnetron problem, but in fact it had to do with the PEI. After numerous attempts to reset and retry, the line was purged and two engineers went into the power room to check the PEI for faults. They found none, but did power cycle things, and when they returned the system worked again. b) There were a couple of SCBA accesses between the second and third boronizations, and a PURGE 5 had to be done before each. Apparently the PLC logic is such that after such a sequence a PURGE60 has to be done before the diborane fill for boronization can be done. Joe Bosco was able to circumvent this roadblock, but not before more than enough time to have actually done the extra PURGE60 had elapsed. Scorecard: ---------- Tests 0 Duds 2 Fizzles 4 Plasmas 16 (including 3 early disruptions) ======== == Shots 22 |
| Session Leader Comments | |||
| Nov 30 2005 09:09:42:557AM | 1051130001 | Bruce Lipschultz | dud |
| Nov 30 2005 09:31:09:133AM | 1051130002 | Bruce Lipschultz | 1.2 MA, nl04=0.9 e20, rampdown at 1.2 seconds (leftover from last week's programming).
dPrad/dt ~ 4-6, slightly lower than last week. H89 ~ 1.3, 104 kJ try to lengthen shot |
| Nov 30 2005 09:53:25:587AM | 1051130003 | Bruce Lipschultz | 1.2 MA, nl04=0.9 e20, rampdown at 1.5 seconds. Disrupt during rampdown.
dPrad/dt ~ 4-6, dropping during shot. H89 ~ 1.2, < 100 kJ boronize now. |
| Nov 30 2005 10:55:18:230AM | 1051130004 | Bruce Lipschultz | 1.2 MA, nl04=0.9 e20, first shot after boronization - scan from 85-95 cm, pause at 90 (85/90/95) for 20 minutes, 100% duty cycle, 10% diborane.
dPrad/dt ~ 2-3, dropping during shot, lower that before boronization. H89 ~ 1.4, sslightly over 100 kJ take another to see if it degrades |
| Nov 30 2005 10:57:49:497AM | 1051130005 | Bruce Lipschultz | fizzle |
| Nov 30 2005 11:19:27:713AM | 1051130006 | Bruce Lipschultz | 1.2 MA, nl04=0.9 e20, second shot after boronization - scan from 85-95 cm, pause at 90 (85/90/95) for 20 minutes, 100% duty cycle, 10% diborane.
dPrad/dt ~ 2-3, dropping during shot, lower than before boronization. H89 ~ 1.4, sslightly over 105 kJ Very similar to shot 4. No obvious degradation. take another to see if it degrades |
| Nov 30 2005 11:39:54:887AM | 1051130007 | Bruce Lipschultz | fizzle |
| Nov 30 2005 11:53:25:963AM | 1051130008 | Bruce Lipschultz | 1.2 MA, nl04=0.9 e20, third shot after boronization - scan from 85-95 cm, pause at 90 (85/90/95) for 20 minutes, 100% duty cycle, 10% diborane.
dPrad/dt ~ 2-4, dropping during shot, lower than before boronization. H89 ~ 1.4, sslightly over 105 kJ Slightly higher dprad/dt. Slightly degraded. take another |
| Nov 30 2005 12:23:35:887PM | 1051130009 | Bruce Lipschultz | 1.2 MA, nl04=0.9 e20, third shot after boronization - scan from 85-95 cm, pause at 90 (85/90/95) for 20 minutes, 100% duty cycle, 10% diborane.
dPrad/dt ~ 3-5, dropping during shot, still lower than before boronization. H89 ~ 1.4, slightly over 105 kJ Slightly higher dprad/dt. Slightly degraded. take another |
| Nov 30 2005 12:24:39:747PM | 1051130010 | Bruce Lipschultz | 1.2 MA, nl04=0.9 e20, fourth shot after boronization - scan from 85-95 cm, pause at 90 (85/90/95) for 20 minutes, 100% duty cycle, 10% diborane.
dPrad/dt ~ 3-5, similar to shot 9, so not continued degradation. set up for another boronization (75/80/85) |
| Nov 30 2005 01:30:26:090PM | 1051130012 | Bruce Lipschultz | 1.2 MA, nl04=0.9 e20, first shot after boronization - scan from 75-85 cm, pause at 80 (75/80/85) for 20 minutes, 100% duty cycle, 10% diborane.
relying on density feedback using Z meter dPrad/dt ~ 1.2-1.8, slightly better than shot 4. repeat to see how this changes. |
| Nov 30 2005 01:47:41:090PM | 1051130013 | Bruce Lipschultz | 1.2 MA, nl04=0.9 e20, second shot after boronization - scan from 75-85 cm, pause at 80 (75/80/85) for 20 minutes, 100% duty cycle, 10% diborane.
relying on density feedback using Z meter dPrad/dt ~ 2.0-2.6, slightly higher than shot 12: repeat to see how this changes. |
| Nov 30 2005 02:04:38:747PM | 1051130014 | Bruce Lipschultz | 1.2 MA, nl04=0.9 e20, third shot after boronization - scan from 75-85 cm, pause at 80 (75/80/85) for 20 minutes, 100% duty cycle, 10% diborane.
disruption, no good. |
| Nov 30 2005 02:04:52:090PM | 1051130015 | Bruce Lipschultz | 1.2 MA, nl04=0.9 e20, fourth shot after boronization - scan from 75-85 cm, pause at 80 (75/80/85) for 20 minutes, 100% duty cycle, 10% diborane.
disruption, no good. |
| Nov 30 2005 03:21:33:903PM | 1051130016 | Bruce Lipschultz | dud |
| Nov 30 2005 03:21:57:543PM | 1051130017 | Bruce Lipschultz | disrupted early again. |
| Nov 30 2005 03:39:01:933PM | 1051130018 | Bruce Lipschultz | Still running on the boronization centered on 80 cm. We have had 3 full lemgth shots and 3 disruptions.
dPrad/dt back up to ~ 4. H89 ~ 1.3 on the first H-mode. Running out of time - do the 70 cm radius boronization |
| Nov 30 2005 04:43:48:510PM | 1051130019 | Bruce Lipschultz | Post boronization 65/70/75, 20 minutes, 100% duty cycle.
fizzle |
| Nov 30 2005 05:41:35:637PM | 1051130020 | Bruce Lipschultz | 1st shot post-boronization (65/70/75), 20 minutes, 100% duty cycle.
dprad/dt high on the first H-mode (2.7) but very low afterwards - close to zero. Lots of injections as we always see post-boronization. H approaching 1.5 and higher stored energy. Definitely got longer lasting H-modes (lower dPrad/dt) Another shot. |
| Nov 30 2005 05:13:28:060PM | 1051130021 | Bruce Lipschultz | 2nd shot post-boronization (65/70/75), 20 minutes, 100% duty cycle.
dprad/dt again high on the first H-mode (3.2) but very low afterwards - close to zero. Fewer injections. H approaching 1.4 and stored energy> 100 kJ. Second H-mode very long as the radiation was rising so slowly. Another shot. |
| Nov 30 2005 05:40:16:073PM | 1051130022 | Bruce Lipschultz | 3rd shot post-boronization (65/70/75), 20 minutes, 100% duty cycle.
dprad/dt even higher on the first H-mode (4-5) and higher on the subsewuent H-modes. H approaching 1.4 on first H-mode. Fewer H-modes because the radiation rising faster. That's it for the day. |
| Physics Operator Comments | |||
| Nov 30 2005 07:08:38:167AM | Steve Wolfe |
Setting up for 1051130 MP#440:
Import seg2 from 1051121015. This is the shot Bruce
calls for in the SL plan. It has the screwy late
sweep down in ZCUR position after 1.2sec, then back up after
1.5sec, for unknown reasons, but that's what he asked for
so that's what he'll get.
Ip is programmed to start ramping down at 1.2sec,
but TF stays at 4.2T until 1.5sec. Why ask why?
NL04 is programmed to 0.9e20 to 1sec, then negative to
turn gas off during prospective ohmic H-mode. No seg2
pg3 puff. Also no pg1 puff, and we've asked for no Ar/Ne
anyway. Change the seg title to "1.2 MA, 4.25T ohmic H-mode".
Keep seg1 from Ian's run yesterday (1051129033),
but with pg4 increased from 10ms to 22msec since we
aren't doing gate valves closed today.
Note: ic_ef4u=-1320, br0=0.0000
oh1_volt is 150V, but EF3 and OH2's have been tweaked
relative to 1050525002
This is supposed to be like Ian's recommended 1051101023,
except 1ms longer pre-puff and perhaps 5A on ef4. It was
working nicely yesterday, we'll see how it does pre- and
post-boronization
Do a load, got one Factor warning due to timestamp bug,
No wirename warnings.
Load at 30-Nov-2005 07:07:54.00
Open tree /home/wolfe/pcs_scratch -1
Open tree done
| |
| Nov 30 2005 09:06:06:760AM | 1051130001 | Steve Wolfe | Shot#1: First try for pre-boronization ohmic H-mode, 1.2MA Dud. So much for Ian's magic startup. pressure was down to .035 or so; we're back on two turbo's, base pressure was 3e-7 Next shot: raise the pre-puff |
| Nov 30 2005 09:26:21:133AM | 1051130002 | Steve Wolfe | Shot#2: PG4 from 22 to 29msec. Probably too much, but I'd rather have a fizzle than another dud. plasma full length with H-modes. Wmhd a little over 100kJ, prad_main peaks at 1.1MW or so. One injection at 0.5sec. Startup looks ok, pressure at .05mTorr Next shot: try extending current flattop (per SL) |
| Nov 30 2005 09:37:51:667AM | 1051130003 | Steve Wolfe | Shot#3: Extend Ip flattop to 1.5sec, get rid of zcur sweep after 1.2sec plasma to 1.71sec, during rampdown, probably ef2l going to zero before ef2u. Next: 20 minutes boronization before next plasma |
| Nov 30 2005 10:48:48:450AM | 1051130004 | Steve Wolfe | Shot#4: 20 minutes boronization after previous plasma reduce pre-puff from 29ms to 12msec, which is similar to what was done last campaign for first post-boronization shot (Actually, it was down to 8ms in August, but we seem to want to be a little higher normally now). Try tweaking the rampdown a little to avoid the disruption: Stop ZXL from sweeping up past +0.03 after 1.7sec Leave RXL flat at 0.005 in rampdown instead of moving in. Base pressure when the ion gauge came back on was already 2e-6. Go straight to INIT. P0=1.5e-6 in pulse plasma full length. One bounce (or injection) in startup, but no hards. Pressure at startup is .025mTorr on the ratiomatic, well below what had a dud on shot#1. Peak of Prad_main is still around 1.1-1.2MW, max stored energy is ~105kJ, same as before. next shot: raise PG4 and try again. |
| Nov 30 2005 11:00:55:870AM | 1051130005 | Steve Wolfe | Shot#5: PG4 from 12 to 29msec (back to original value) Turns out that the EF2's went to zero again on shot 4, but came back on. My changes probably didn't help. 1.5e-6 in pulse, this one fizzled. P0 up to .055mTorr looks like it's too much. Next: back off to 27msec |
| Nov 30 2005 11:15:00:823AM | 1051130006 | Steve Wolfe | Shot#6: PG4 from 29 to 27msec (back to original value) plasma full length. five H-modes, similar peaks on prad and Wmhd. P0 at bd ~.050mTorr next shot: repeat, still seeing some B effects so we're not ready to go to the next boronization condition yet. |
| Nov 30 2005 11:25:40:903AM | 1051130007 | Steve Wolfe | Shot#7: repeat 1.4e-6 entering pulse fizzle. very late breakdown 13msec Bz went up by ~1mT? next shot: ef4 more negative by 10A |
| Nov 30 2005 11:43:08:963AM | 1051130008 | Steve Wolfe | Shot#8:ef4 from -1320 to -1330 pg4 from 27ms to 28ms plasma full length. Breakdown back at 5.9msec, slight bounce Bz still looks positive; I did load the change, but it doesn't look like it did much. More and shorter H-modes Next: No changes, see what happens |
| Nov 30 2005 11:53:39:713AM | 1051130009 | Steve Wolfe | Shot#9: No changes, see what happens plasma to 1.7sec, lots of H-modes, still better than pre-B, I think. next shot: drop pg4 (Ian says it's too high) |
| Nov 30 2005 12:04:55:073PM | 1051130010 | Steve Wolfe | Shot#10: drop pg4 from 28 to 27msec plasma full length. nl04 has a fringe jump but looks like feedback was ok. next: Go on to next boronization: 75/80/85 |
| Nov 30 2005 12:41:44:777PM | 1051130010 | Steve Wolfe | Problem getting the boronization started, seems to be a PEI fault of some kind. Starts up ok after an SCBA power room access to check it out found nothing wrong. |
| Nov 30 2005 01:14:10:200PM | 1051130011 | Steve Wolfe | Shot#11: drop pg4 from 27 to 12msec for post-boronization There may be a problem with TCI, so import an nl_zmeter wire from 1040408005 wire 14 onto seg2 wire 11. Set gain from 9 to 0; I won't use it this time anyway, but I want to have it available. It looks like the right waveform is something like 0.1V; load that in, to see what it looks like. I may be better off using a pre-programmed gas though. Wait until 2e-6 base before INIT (was at ~4e-6) fizzle. breakdown a little late, Bz looks negative again. NL04 feedback signal totally destroyed. Next: change to nl_zmeter feedback, raise pg4 to 20msec |
| Nov 30 2005 01:30:01:903PM | 1051130012 | Steve Wolfe | Shot#12:PG4 from 12msec to 20msec NL04 feedback off, NL_ZMETER feedback on at gain 9 PG3 waveform at 50V to 0.6sec plasma to 1.7sec, bouncy startup, maybe some runaways TCI is definitely otl. H-modes start at 0.9 or so, looks like density is too high. Drop nl_zmeter program from .1 to .07 |
| Nov 30 2005 01:42:44:277PM | 1051130013 | Steve Wolfe | Shot#13:PG4 from 20 to 27msec Drop nl_zmeter program from .1 to .07 tweak seg2 gas pg3 program a little. plasma to 1.75sec. nl04 seems to be working ok this time, since I'm not using it. First hmode is at .65sec, nl04~.83e20, similar to earlier cases. I think the nl_zmeter feedback is ok now. Startup still has a bounce. PG4 still seems to be at 20msec? I may not have applied the ALL_V change. Do it now |
| Nov 30 2005 01:57:01:277PM | 1051130014 | Steve Wolfe | Shot#14:PG4 from 20 to 27msec (load it this time) Plasma disrupts at 0.64sec. Injection? Big drop in density early following what look like internal disruptions. NL_ZMETER doesn't do so well on those. next shot: Drop the zmeter gain some, |
| Nov 30 2005 02:14:28:700PM | 1051130015 | Steve Wolfe | Shot#15: Reduce nl_zmeter gain from 9.0 to 5.0 reduce pg3 program in seg2 Another early disruption; PF breaker pulled after. OH1 crowbar, self-power circuit fired. Needs an SCBA power room access, so may as well let Sam go to the cell to fix TCI as well. Next shot: If Sam can get TCI re-aligned, then go back to NL04 feedback. Otherwise, go to preprogram pg3 until later in seg2. |
| Nov 30 2005 02:29:01:887PM | 1051130015 | Steve Wolfe | While I'm waiting, copy the pulse gas trace from shot 10 into pg3 V program. However, Sam is fixing the TCI now, so I'll probably remove it. |
| Nov 30 2005 02:54:07:980PM | 1051130016 | Steve Wolfe | Shot#16: Turn on NL04 feedback, turn off NL_ZMETER, Re-zero PG3 in seg 2. Dud. Fields are ok, pressure is at .045 ??? next: raise pg4 to 29msec |
| Nov 30 2005 03:17:01:747PM | 1051130017 | Steve Wolfe | Shot#17:Pg4 from 27 to 29msec Back on NL04 feedback, gain=8 Another early disruption, around 0.6sec doesn't seem to have anything to do with the density feedback Tweak the pg3 puff and the early clearin in seg2 I don't know why these are disrupting, but maybe that will help. |
| Nov 30 2005 03:34:45:870PM | 1051130018 | Steve Wolfe | Do another boronization before the next shot. This one should be at 65/70/75sec |
| Nov 30 2005 04:11:10:857PM | 1051130018 | Steve Wolfe | Shot#18:Add some pg3 puff in seg2 Reduce clearin before 0.6 from .005 to .001 like it is later in flattop I don't know why these last shots disrupted, but maybe that will help. plasma to 1.75sec, lots of H-modes The CLEARIN change made the early inner gap (and also outer gap) smaller, closer to touching during crossover. On the other hand, n/nc is lower at .5 to .7, maybe that was the problem? I could probably stand moving RCUR a little further in between .2 and .45sec, to avoid bouncing on the outside. Ratiomatic trace on this one looks like it is from between shots, it's flat on the -7 scale. SCBA power room access for a power supply fault. |
| Nov 30 2005 04:34:42:887PM | 1051130019 | Steve Wolfe | Shot#19: After 20 minutes of boronization, lower pg4 to 16msec (from 29) Reduce gain on Nl04 from 8 to 5 after 200msec to try to reduce strong oscillation on gas puff demand. Also slow down the clearin ramp in rampdown to try to keep EF2's off zero. While I'm at it, move RCUR 2mm smaller before .45sec, to try to protect the outside around crossover. Hopefully this won't undo the smaller n/nc from shot 18. fizzle. Looks like pressure was too low, two bounces next: pg4 to 25msec, hope for the best |
| Nov 30 2005 04:50:03:387PM | 1051130020 | Steve Wolfe | Shot#20: pg4 from 16 to 25msec. plasma to 1.75sec, looks like no improvement in the rampdown although the ef2's are now off the rail until the disruption. Chasing a red herring there? Four h-modes including one in rampdown. Rather small runaway dump early on, nothing serious. next: pg4 up to 27msec |
| Nov 30 2005 05:03:54:700PM | 1051130021 | Steve Wolfe | Shot#21: pg4 from 25 to 27 msec. plasma to 1.65sec, made it to rampdown anyway. Two longer Hmodes in flattop, one more in rampdown, with a big MHD mode on it. This was probably the best H-mode behavior of the day. Next: One more shot, no changes. |
| Nov 30 2005 05:13:15:840PM | 1051130022 | Steve Wolfe | Shot#22: One more shot, no changes. plasma to 1.7sec. Three H-modes, plus maybe one more in rampdown. Perhaps not as good as 21, but not too bad. That's all for today. Overnight boronization before tomorrow's RF run. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:02:28:603AM | Plasma | Ok | |
| 2 | 09:15:10:840AM | Plasma | Ok | |
| 3 | 09:30:39:450AM | Plasma | Ok | |
| 4 | 10:42:57:247AM | Plasma | Ok | |
| 5 | 10:55:18:560AM | Plasma | Ok | |
| 6 | 11:07:48:137AM | Plasma | Ok | |
| 7 | 11:20:32:183AM | Plasma | Ok | |
| 8 | 11:33:13:933AM | Plasma | Ok | |
| 9 | 11:46:45:653AM | Plasma | Ok | |
| 10 | 11:59:15:510AM | Plasma | Ok | |
| 11 | 01:08:11:510PM | Plasma | Ok | |
| 12 | 01:21:17:200PM | Plasma | Ok | |
| 13 | 01:33:47:857PM | Plasma | Ok | |
| 14 | 01:47:20:200PM | Plasma | Ok | |
| 15 | 01:59:55:480PM | Plasma | Ok | PF breaker opened the disruption |
| 16 | 02:50:31:277PM | Plasma | Ok | |
| 17 | 03:02:56:903PM | Plasma | Ok | |
| 18 | 03:18:18:387PM | Plasma | Ok | |
| 19 | 04:31:01:903PM | Plasma | Ok | |
| 20 | 04:43:21:417PM | Plasma | Ok | |
| 21 | 04:55:49:167PM | Plasma | Ok | |
| 22 | 05:08:18:527PM | Plasma | Ok | |