| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Steve Wolfe |
| Physics operator(s): | Earl Marmar |
| Engineering operator(s): | Gary Dekow,Frank Silva,Bill Cochran |
| Engineering Operator Run Comment |
| MP206 Restart Operation/Wolfe/Marmer |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:18:773PM |
| Author: To Be Determined |
| Session Leader's Summary of Fri 29-JAN-1999 MP 206 Restart Operation 1999 SL: wolfe PO: Marmar Asst. PO: parker EO: Silva,Cochran,Dekow This run was a continuation of the attempts to clean up the machine and get plasmas. Today's run was quite successful, and we now seem to be over the hump. We got 13 plasmas and only 4 fizzles, and succeeded in getting both limiter and divertor shots into rampdown. Helium ECDC between shots was tried today in an effort to improve the reliability; this was apparently somewhat successful (see the Physop summary for details). ----------------------------------------------------------------------------- Run Plan: Continue trying to get decent plasmas. We are starting from 990128021, which is programmed as a limiter discharge, and has a corrected CLEARIN predictor factor. It will likely be necessary to tune up the discharge after looking at what the first real plasma does. [ Contrary to what I said in the run summary yesterday, the factor error was not present last year. It was introduced on Wednesday when we recalculated the predictors after replacing the Bp coil. ] We will be trying ECDC in Helium between discharges today, to try to improve the cleanup. It's worth a try, but I'm afraid the only way to clean this machine up is tokamak discharges. If we get limiter discharges running well and seem to be cleaning up the inner wall, then we will go back to divertor discharges. Note that if we reload from yesterday or the day before, we will have to reset the CLEARIN factor. ------------------------------------------------------------------------------- Results: -------- The first shot disrupted early, probably due to a gas problem when the TCI failed. The TCI feedback was then turned off for most of the rest of the day. We ran most of the day with no density feedback and the maintenance gas level in the second segment (#4) set to zero, so the fueling was almost entirely from the walls. Shots 1 and 2 were based on 990128021. #3-15 had the ZXL and ZXU moved away and CLEARIN=-.04, and were inboard limited, with some scrapeoff flux going into the lower divertor. As we continued to run these limiter discharges with no D2 puffing in the main flattop, the density dropped from 1.2e20 to 7e19. Attempts to fix the rampdown to avoid a disruption around 1.3 sec were not very successful. Shots 16 and 17 were divertor discharges, similar to 980120003 but with Ip programmed for 700kA instead of 800. These were obtained by import_Segment from 990128018 and correcting the factor on wire4, and making some additional minor tweaks. Shot 16 was programmed for 5e19, which we got without opening the gas valve. This shot ramped down nicely. Shot 17 asked for 8e19 and got about 9e19, thanks to an increase in the maintenance level. It lasted to 1.38 sec. Both were nice looking diverted discharges, although with high H/D ratios. The "Irby Criterion" on both base pressure and individual partial pressures on the RGA was successfully violated on many discharges. Base pressures up to 5e-7 were run with successful startups. It was possible to run mass 28 partial pressures at least a factor of 2 above the previous maximum and still get good plasmas, particularly after He ECDC. The between-shots wait period was reduced from one hour to about 20 minutes. Part 1 of this MiniProposal, "Get Plasma" is now complete, and we have made some progress on part 2, "Cleanup discharges, increase reliability". Diagnostic alignment (part 3) can proceed next week during dedicated runs. We will also be documenting the behavior prior to boronization. |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:36:59:927PM |
| Author: To Be Determined |
| Physop summary for 990129 continuation of MP 206: Restart Operations 1999 PO: Marmar, Goetz PO': Parker SL: Wolfe EO: Silva, Dekow Considerable progress in the cleanup was made today, with 13 plasmas making it at least to current flattop. Many plasmas made it to the beginning of ramp-down, and one (shot 16) was nicely diverted and ramped down to .25 MA before disrupting. Shot 17 had a measurable density rise due to the deuterium puff, with flattop nl_04 of about 8e19, under feedback control. H/D ratios were high all day. Rice reports that Mo was increasing and chlorine decreasing through the day. We performed between shot ECDC in helium before many of the discharges, in an attempt to assess the possible benefits on cleanup. Details can be found in the logbook; the main observational statistics are as follows: The shots which were preceded by helium ECDC, and which followed a plasma shot, were also plasma shots in 8 out of 9 such attempts. Shots which followed a plasma shot, but did not have helium ECDC, resulted in fizzles for all 3 such attempts. All fizzles (4 total) were followed by plasmas without intervening ECDC. The Irby criteria for RGA measured partial pressures, as established from yesterday's run, were exceeded, for at least some of the masses, on all attempts today after shot 1. Starting with shot 9, we tried to keep the time in recool after a plasma shot to about 20 minutes (shot 4, the first no-ECDC post-plasma fizzle, was preceded by a one hour wait; shot 4 may also have had a B_R offset problem, although that appeared no worse than on shot 3). So, every shot today (after shot 1) that yielded plasma, was preceded either by intershot helium ECDC, or by a fizzle. The main impurities showing up on the RGA after plasmas continue to be hydrocarbons, CO and CO_2. Engineering systems performed well today; shot 13 terminated prematurely as a result of an OH2L crowbar at 0.45 s; there were no obvious signs of problems with the supply, and the problem did not recur. Operation of the between shot ECDC went very smoothly. Summary: 13 plasmas 4 fizzles 0 duds ------------ 17 attempts |
| Session Leader Comments | |||
| Jan 29 1999 08:49:27:373AM | Steve Wolfe | Run Plan: Continue trying to get decent plasmas. We are starting from 990128021, which is programmed as a limiter discharge, and has a corrected CLEARIN predictor factor. It will likely be necessary to tune up the discharge after looking at what the first real plasma does. [ Contrary to what I said in the run summary yesterday, the factor error was not present last year. It was introduced on Wednesday when we recalculated the predictors after replacing the Bp coil. ] We will be trying ECDC in Helium between discharges today, to try to improve the cleanup. It's worth a try, but I'm afraid the only way to clean this machine up is tokamak discharges. If we get limiter discharges running well and seem to be cleaning up the inner wall, then we will go back to divertor discharges. Note that if we reload from yesterday or the day before, we will have to reset the CLEARIN factor. | |
| Jan 29 1999 09:04:50:543AM | 990129001 | Steve Wolfe | shot #1: from 990128021, with less pg3 in seg1 plasma - 330ms, 660kA tci crapped out early |
| Jan 29 1999 10:47:41:000AM | 990129002 | Steve Wolfe | shot #2: plasma to .55sec, 730kA. sawtoothing merrily along ha event at .51 nl4 feedback was off , nl4 reached 1.1 e20 It's an x-point discharge at .18 and .38 and at .540 according to efit If we want it limited, we need to back off clearin further (and RCUR) and drop ZXL and maybe raise ZXU ZCUR is satisfied on the hybrid, thinking it has -10000, but the actual position looks to be near zero. |
| Jan 29 1999 11:18:09:640AM | 990129003 | Steve Wolfe | shot #3: Drop zxl, raise zxu, clearin from -.03 to -.04, rcur negative by 0.005, PG3 maintenance level to zero in seg 4. plasma to 1.29sec, 730ka flattop into rampdown. Vsurf = 1.6V, good limiter discharge. nl4 with no gas is flat at 1.1 to 1.2e20 peak Te before sawteeth is 2keV, drops to 1 by end of shot. No ecdc after this shot. watching the rga. Note: we have now run three shots in a row (with an hour in between of course) and gotten to flattop The Tuesday goals are now met, sort of. |
| Jan 29 1999 12:02:42:140PM | 990129004 | Steve Wolfe | shot #4: no changes. Run after an hour, Irby criterion not met. fizzle. Br is negative, but it was on the previous one too. |
| Jan 29 1999 12:36:58:373PM | 990129005 | Steve Wolfe | shot #5: br tweak (1mT more positive) and go again, still not satisfying Irby criterion. plasma, 1.28sec nl4=1.18e20, no fin, no halpha problem, rampdown may have program problem. |
| Jan 29 1999 01:15:39:263PM | 990129006 | Steve Wolfe | shot #6: some rampdown changes. ecdc before this shot for 20minutes; 44 is rising; still well over Irby criterion, base=4.6e-7 plasma. So much for the Irby criteria. ece gate valve was closed. NL4 = 1.0e20; it's dropped from previous shot. Still have a rampdown disruption, at the same time. n/nc is rising this time, > 1.3. |
| Jan 29 1999 01:36:02:810PM | 990129007 | Steve Wolfe | shot #7: Ramp the Zx's away during rampdown. Reduce pre-puff again. 20min ecdc; base=7e-7 fizzle. late bd. |
| Jan 29 1999 02:00:24:293PM | 990129008 | Steve Wolfe | shot #8:plasma. Still disrupts at 1.3sec nl4=0.9e20 (it dropped again) |
| Jan 29 1999 02:19:24:780PM | 990129009 | Steve Wolfe | shot #9: 5 minutes ecdc. Clearin and rcur tweaks in rampdown. plasma, same length. nl4=1.0e20 didn't drop that time. |
| Jan 29 1999 03:00:22:263PM | 990129010 | Steve Wolfe | shot #10: no ecdc. Wait until base p is down to 5e-7; Extend tf program by .15sec, move Ip controller switch from 1.05 to 1.5sec fizzle |
| Jan 29 1999 03:00:02:857PM | 990129011 | Steve Wolfe | shot #11: no ecdc. Wait until base p is down to 3.4e-7; Extend tf program by .15sec, move Ip controller switch from 1.05 to 1.5sec plasma disrupts at .9sec, nl4=1.4e-7, EF4 maybe on current rail at 3700a |
| Jan 29 1999 05:33:33:733PM | 990129012 | Steve Wolfe | shot #12: 5minutes of ecdc, reduce ic_ef4 from 3500 to 3000. move rcur out 5mm to reduce outer gap. start sequence at 20min. plasma to 1.15, density rises to almost 2e20 at the end. |
| Jan 29 1999 03:52:56:793PM | 990129013 | Steve Wolfe | shot #13: plasma disrupts at 0.45 - OH2l crowbars before disruption. COMM failure, no blown fuses. Looked like an ok shot until the ps suicided. |
| Jan 29 1999 03:59:15:513PM | 990129014 | Steve Wolfe | shot #14: no ecdc, wait 20 minutes. fizzle, bd at 6.5msec, bouncer |
| Jan 29 1999 04:23:13:607PM | 990129015 | Steve Wolfe | shot #15: plasma to 1.42sec, shark fin at the end. nl4=7.5e19 until fin. looks good. Next shot, try a diverter |
| Jan 29 1999 04:47:24:670PM | 990129016 | Steve Wolfe | shot #16: Import seg4 of 990128018 into seg2, and correct the clearin factor and drop the pg3 maint level to zero. Also, extend the TF as on shot 15, and drop IC_EF4 to 3000, as above. ecdc for about 15 min. plasma to 1.63sec nl4=5e19 and rising slowly left gap=1.4cm, right gap=1.4cm note that NL4 feedback was on, but we asked for 5e19, so the valve never openes Nice shot. |
| Jan 29 1999 05:05:31:107PM | 990129017 | Steve Wolfe | shot #17: ecdc for 5min. ask for nl4=8e19, put back some maint. gas. plasma to 1.38sec nl4=8.7e19 rising at the end. vsurf=1.33, te 1.4-1.6kev another nice shot. |
| Physics Operator Comments | |||
| Jan 29 1999 08:19:13:077AM | Earl Marmar | MP: 206 Restart Operation, 1999 Overnight ECDC in D2 Engineering Setup same as shot 990128020 cryopump closed TF under hybrid control Gas setup - fill B-top with 6 psi of D2 Hybrid enabled fill B-side lower with 6 psi of Helium NOT hybrid enabled fill "K-side"* with 30 psi of D2 Hybrid enabled Helium should be open to the plenum Start from PCS settings for 990128021, which should be a limited shot. We will continue observing the pumpout criterion after a successful plasma, before trying for the next shot. For part of the time between shots, we will ECDC, first in helium, and later in the run, possibly in deuterium. | |
| Jan 29 1999 09:12:52:827AM | 990129001 | Earl Marmar | hybrid coldstart complete; no errors; all matrices respond load from 990128021 reduce PG3 voltage prog slightly in seg 1 plasma - nice breakdown - good current rise disruption @ .325s; density feedback goes south @ 0.19s |
| Jan 29 1999 10:03:50:763AM | 990129002 | Earl Marmar | Shot 990129002 15 minutes of helium ECDC before this shot mass 28 and 44 went below the limits immediately mass 32 & 18 oscillating with the sweep, but then slowly reducing mass 14 down immediately and slowly decreasing some argon contamination in the plenum after ECDC shut-off, mass 18, 28, 32, and 44 back up and then coming down slowly mass 44 rising at the rate of 2e-9 / 10 min zero controller for NL04 in segment 4 (TCI laser is oscillating) 60 minutes between shots plasma - disrupts @ .55s good breakdown and current rise limited plasma - 2cm outer gap; EFIT finds two x-points still too much gas x-ray spectroscopy: Cl > S > Mo > Ar |
| Jan 29 1999 11:35:07:623AM | 990129003 | Earl Marmar | Shot 990129003 between shots ECDC in helium turn off PG3 in seg 4 tweaks to Rcur, Zcur, Rxl, Zxu plasma; 1.3 seconds; disrupt during rampdown |
| Jan 29 1999 12:11:59:623PM | 990129004 | Earl Marmar | no ecdc between shots 3 and 4 Irby criiteria not quite satisfied; going after 1 hour wait; base pressure = 1.7e-7 rampdown tweaks after 1.2 s RCUR in ZXU up ZXL down fizzle B_R about 2 mT negative; this was also true on shot 3 |
| Jan 29 1999 12:28:02:890PM | 990129005 | Earl Marmar | B_R offset to .003 T from .002 Base pressure 1.7 Irby criteria still not satisfied on all masses plasma; similar to shot 3; disrupt at 1.3 s |
| Jan 29 1999 01:06:41:780PM | 990129006 | Earl Marmar | ECDC between shots 5 and 6; in helium for 20 minutes keep RCUR and CLEARIN constant during rampdown keep EF2 by EF4 constant at 2000 during rampdown take 1 ms off prefill puff (now 15 ms) base pressure 4.8e-7 plasma; so much for the Irby criterion looks much like shot 5; disrupt in rampdown at 1.32 s density somewhat lower |
| Jan 29 1999 01:34:43:123PM | 990129007 | Earl Marmar | ECDC in Helium between 6 and 7 for 15 minutes rampdown changes: ZXU up ZXL down Also, 1 more ms off prefill puff (now 14 ms) base pressure 5.4e-7 fizzle |
| Jan 29 1999 02:00:16:217PM | 990129008 | Earl Marmar | add 1 ms to prefill puff (now 15 msec) base pressure 3.2e-7 plasma; disrupting at the same place. |
| Jan 29 1999 02:18:49:483PM | 990129009 | Earl Marmar | ECDC 5 minutes before shot 9 rampdown tweaks: RCUR in CLEARIN in base pressure 4.6e-7 plasma disrupt at 1.32 |
| Jan 29 1999 02:35:34:780PM | 990129010 | Earl Marmar | no ECDC before shot 10 wait for 20:00 minutes extend TF flattop to 1.35 Ip controller shift delayed to 1.5 s from 1.05 s base pressure 4.9e-7 fizzle |
| Jan 29 1999 02:58:36:733PM | 990129011 | Earl Marmar | no changes wait 13 minutes base pressure 3.4e-7 plasma; disrupt at .88 s |
| Jan 29 1999 03:15:36:500PM | 990129012 | Earl Marmar | ECDC 5 minutes in He before shot 12 reduce EF4 current prog from 3500 to 3000 amp during flattop RCUR out by 5 mm to reduce outer gap wait 21 minutes base pressure 4.0e-7 plasma; disrupt at 1.15 looking dirtier |
| Jan 29 1999 03:49:21:250PM | 990129013 | Earl Marmar | ECDC for 5 minutes in He before shot 13 no other changes wait 20 minutes base pressure 4.4e-7 plasma OH2 lower problem, at time of OH1 crossover; disrupt at .452 s |
| Jan 29 1999 04:04:10:263PM | 990129014 | Earl Marmar | no ECDC before shot 14 wait 20 minutes base pressure 3.9e-7 fizzle |
| Jan 29 1999 04:19:40:827PM | 990129015 | Earl Marmar | no ECDC before 15 wait 12 minutes base pressure 2.9e-7 plasma; ends with a sharkfin at 1.42 s |
| Jan 29 1999 04:47:32:123PM | 990129016 | Earl Marmar | ECDC 10 minutes in He before shot 16 Reload segment 4 from 990128018, into segment 2; attempt a diverted shot tweak pulsed gas and keep TF invert at 1.35 s wait 20 minutes base pressure 5.0e-7 plasma; ramped down; nicely diverted |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:58:14:500AM | Plasma | Ok | no faults/plasma |
| 2 | 09:56:43:750AM | Plasma | Ok | no faults/plasma/ECDC between shots |
| 3 | 10:58:59:030AM | Plasma | Ok | nofaults/plasm/ecdc between shot |
| 4 | 11:57:53:390AM | Plasma | Ok | no faults/fizzel |
| 5 | 12:15:53:780PM | Plasma | Ok | no faults/ plasma |
| 6 | 01:00:55:467PM | Plasma | Ok | no faults/plasma |
| 7 | 01:30:00:530PM | Plasma | Ok | No Faults |
| 8 | 01:43:59:327PM | Plasma | Ok | no faults |
| 9 | 02:07:23:920PM | Plasma | Ok | no faults/plasma |
| 10 | 02:30:16:450PM | Plasma | Ok | No Faults |
| 11 | 02:46:19:530PM | Plasma | Ok | No faults |
| 12 | 03:10:19:903PM | Plasma | Ok | No Faults |
| 13 | 03:33:16:577PM | Plasma | Bad | Faults on OH2L Com, EF1L Auto Crowbar, OH1 Auto Crowbar |
| 14 | 03:55:26:670PM | Plasma | Ok | No faults |
| 15 | 04:11:03:043PM | Plasma | Ok | No faults |
| 16 | 04:34:44:250PM | Plasma | Ok | No Faults |
| 17 | 04:58:04:483PM | Plasma | Ok | No Faults |