| Miniproposals | ||||||||||
|
| Operators | |
| Session leader(s): | Martin Greenwald |
| Physics operator(s): | Steve Wolfe |
| Engineering operator(s): | Unknown |
| Engineering Operator Run Comment |
| mp 166 |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:18:303PM |
| Author: To Be Determined |
| Run Plan for 980220 mp 166 density limits with pellets Session Leader - Greenwald Phys Op - Wolfe ============================ Plan: The object of the run is to test density limits with pellet injection. We'll try to explore both the L-mode disruptive limit and the H/L transition limit. Given the limitations on power, the H-mode work will probably have to be at 0.6 MA. We could do the L-mode work at .8 or 1.0 MA - the higher value gives us more headroom but bigger disruptions. We should probably start at 0.8 Bt = 5.65 to give us a chance of getting Te profiles. 1. starting with OH plasmas, Ip=.8 MA, ne targets ~ 1.5-2 e20 The pellet size, number and timing will be varied to give a maximum density in quasi-steady state. 2. next turn on RF heating ~ 2.5 MW, Ip= .8 MA, ne targets ~ 1.5-2 e20 The pellet size, number and timing will be varied to give a maximum density in quasi-steady state. We may get intermittent H-modes until the density gets above 3-4 e20 3. As above but at .6 MA, In this case the density limit is down to 4e20 where we can sustain H-modes ============================== Results: We finished parts 1 and 2 of the plan, conditions didn't look favorable for H-mode studies. The machine was running very well, we had a record 41 shots in a row, the injector was also running reliably - we injected 6-12 pellets on virtually all shots. Pursuing the density limit this way is not easy, but we got convincing looking scenarios at .6 and .8 MA. We didn't quite have enough time to optimize at 1 MA. If the pellets are injected too aggressively, we extremely high densities > 10^21, highly peaked, P-mode/PEP mode type discharges. Additional pellets will then cause disruptions. Impurity accumulation in the enhanced confinement mode may be partly responsible. If we back off too much, the plasma is too hot and pellet penetration is too shallow. We see good mass accountability, but the density pumps out in as little as 5 msec. The RF coupling is also sensitive, Agressive pellet fueling can cause trips in the RF. If these last long, the plasma will cool and subsequent pellets will penetrate through the axis. Typically the plasma can take at most one of these - additional pellets usually cause disruptions. It seems always possible to exceed the empirical limit transiently with one or two big pellets. Exceeding it in quasi-steady state was not possible today. On several shots, the pellet fueled density buildup allowed us to gradually probe the limit. At .6 and .8 MA the plasma disrupted about 10% below the empirical limit. We had lots of misc. pellet phenomena - P-modes, PEP, snakes, MHD. The early ohmic shots showed a 50% improvement in global confinement during the P-mode. ================================ Shots suitable for further analysis include: (There is probably something of interest in every shot, those listed here demonstrate behavior of special interest.) start of .8 MA 980220003,4,5 Fiducials 980220007 ohmic, 4 pellets, 4 p-modes 980220008 longish ohmic p-mode 980220009,10 ohmic, strong mhd during p-mode 980220011,12 excellent p-mode, 60% increase in stored energy, mhd 980220013 RF, PEP mode and H-mode together, snake 980220014 baseline - no pellets 980220018 RF, PEP and H-mode, snake 980220019,22 RF, PEP and H-mode, MHD 980220027-30 RF, PEP, great snakes 980220031 8 pellets, 9(!) PEP modes, quasi-steady density 980220032 7 pellets, quasi-steady density - nlimit disruption 980220033 9 pellets, quasi-steady density - nlimit disruption start of .6 MA 980220035,36 7-10 pellets, quasi-steady density - nlimit disruption start of 1 MA 980220041 6 pellets, longish period near 6e20 |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:36:59:600PM |
| Author: To Be Determined |
| Physop Summary for Friday 980220 MP#166 Density Limits (w/ pellets) SL: Greenwald PO: Wolfe Run Plan for 980220 mp 166 density limits Session Leader - Greenwald Phys Op - Wolfe The object of the run is to test density limits with pellet injection. We'll try to explore both the L-mode disruptive limit and the H/L transition limit. Given the limitations on power, the H-mode work will probably have to be at 0.6 MA. We could do the L-mode work at .8 or 1.0 MA - the higher value gives us more headroom but bigger disruptions. We should probably start at 0.8 Bt = 5.65 to give us a chance of getting Te profiles. 1. starting with OH plasmas, Ip=.8 MA, ne targets ~ 1.5-2 e20 The pellet size, number and timing will be varied to give a maximum density in quasi-steady state. 2. next turn on RF heating ~ 2.5 MW, Ip= .8 MA, ne targets ~ 1.5-2 e20 The pellet size, number and timing will be varied to give a maximum density in quasi-steady state. We may get intermittent H-modes until the density gets above 3-4 e20 3. As above but at .6 MA, In this case the density limit is down to 4e20 where we can sustain H-modes Results: -------- A boring run from the Physop's point of view. All the points in the plan were run, plus a number of shots at 1MA. In all the RF cases, the first pellet preceded the RF, so we didn't get to do any H-L points. There were some brief h-modes between pellets. Essentially all the pellet shots disrupted. At 800kA and 600kA, the disruptions were close to the Greenwald density; at 1MA they were at much lower density, even lower than what was done at 800kA. The 1MA cases were cold and radiative (so were a lot of the others). The pelleteers perfected (?) the technique of ramping up the density with a series of up to 10 small pellets. This seemed to be a good way of establishing the limit at 600kA, but the same technique at 1MA led to quite low density disruptions. After the initial fizzle, we had 41 straight plasmas without a fizzle (or any startup tweaks). This surpasses the previous record of 40 straight by IHH, and represents another triumph for benign neglect. Details / Shot summary: ----------------------- See the logbook for detailed details. Shot 1 was a scanner test. Shot 2 was the first plasma attempt (fiducial, segment 4). Fizzled Shot 3 was a good fiducial, after .5mT Br tweak, 5Amp IC_EF4 tweak. The 2pi was under 300kW. Shot 4 was fiducial-like (TF to 5.7T) in Segment 2. Also low Prad, looks good. Shot 5 was the same except RF to 2.8 MW. Still looks ok, 2pi up to 350kW. Rn = 2.4e13 neut/sec, Wmhd=142kJ. Shot 6-12 were ohmic 800kA pellet shots. Shot 13-22 were 2MW RF, 800kA pellet shots. #14 had no pellets: Martin goofed. Only soft landing after #5. Shot 23-33 were 1MW RF, 800kA pellet shots. Shot 24 data lost in DAQA crash. Shot 34-36 were 1MW RF, 600kA pellet shots. Shot 37-43 were 1MW RF, 1MA pellet shots. Shot 44 was another scanner test after the run. Problems: --------- On shot 13, after the shot, we had an EF1L crowbar and a TF crowbar. New instrumentation on EF1 confirmed that the crowbar was due to the self-powered circuit firing, for no apparent reason. The reason for the TF crowbar is unclear, but there seemed to be a noise spike generated when the PF breaker pulled. On shot 24, we lost almost all data to a DAQA crash. Josh oversaw the reboot. We had a couple of other data system/cycle hangs, cleared by Josh. After shot 40, the torus ion gauge (ITG) failed and would not restart. Joe Bosco successfully bypassed the TORVAC GAS-FILL-FAULT so we could continue the run. After the run, Tommy was able to revive the gauge by removing and replacing the connector; the filament was ok. We now have one remaining filament on ITG, and one on the backup gauge on J-port. Anti-problems: ------------- The OH coax resistances were well-behaved all day. Shot 3 was highest at 0.8uohm, mostly .4 to .6 thereafter. The scanner is apparently now working, thanks to Willy and Joe Bosco. Turns that weren't cooling yesterday did get cold today, with some modifications to the cooling. Scorecard: ---------- Tests 2 Duds 0 Fizzles 1 Plasmas 41 ------- -- Shots 44 |
| Session Leader Comments | |||
| Feb 19 1998 06:23:52:670PM | Martin Greenwald | Run Plan for 980220 mp 166 density limits Session Leader - Greenwald Phys Op - Wolfe The object of the run is to test density limits with pellet injection. We'll try to explore both the L-mode disruptive limit and the H/L transition limit. Given the limitations on power, the H-mode work will probably have to be at 0.6 MA. We could do the L-mode work at .8 or 1.0 MA - the higher value gives us more headroom but bigger disruptions. We should probably start at 0.8 Bt = 5.65 to give us a chance of getting Te profiles. 1. starting with OH plasmas, Ip=.8 MA, ne targets ~ 1.5-2 e20 The pellet size, number and timing will be varied to give a maximum density in quasi-steady state. 2. next turn on RF heating ~ 2.5 MW, Ip= .8 MA, ne targets ~ 1.5-2 e20 The pellet size, number and timing will be varied to give a maximum density in quasi-steady state. We may get intermittent H-modes until the density gets above 3-4 e20 3. As above but at .6 MA, In this case the density limit is down to 4e20 where we can sustain H-modes | |
| Feb 20 1998 09:23:20:370AM | 980220006 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 3.2 .7 3 6. .9 3 5. 1.1 3 8. |
| Feb 20 1998 09:36:28:410AM | 980220006 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 3.4 .7 3 6 .9 3 5.8 1.1 2 4.5 |
| Feb 20 1998 09:46:44:930AM | 980220008 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 2.2 .7 3 6.5 .85 2 6 1.0 2 6 1.15 2 plasma gone |
| Feb 20 1998 10:06:01:550AM | 980220009 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 1.7 .7 3 3.8 .85 2 4.0 1.1 2 5.3 |
| Feb 20 1998 10:20:49:260AM | 980220010 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 1.6 .7 3 5.7 .85 2 4.7 (another rise after 0.9 s to 5.4) 1.1 2 Plasma Gone |
| Feb 20 1998 10:24:03:710AM | 980220011 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 6.6 .7 3 6.2 .85 2 5.9 1.1 2 5.5 |
| Feb 20 1998 10:37:36:490AM | 980220012 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 8.4 .6 1 4.6 .7 3 5.9 .8 1 4.1 .9 3 Plasma Gone 1.0 1 Plasma Gone |
| Feb 20 1998 11:12:21:610AM | 980220013 | Martin Greenwald | Good Shot RF added, PEP and H-modes Pellets fired at: Time Size Max Density .5 3 6.9 .6 1 4.3 .7 3 5.4 .8 1 3.8 .9 3 5.2 1.0 1 4.8 |
| Feb 20 1998 11:09:10:130AM | 980220014 | Martin Greenwald | Good Shot No Pellets, operator error |
| Feb 20 1998 11:19:04:570AM | 980220015 | Martin Greenwald | Good Shot RF, no H-mode Pellets fired at: Time Size Max Density .5 3 4.4 .6 2 3.6 |
| Feb 20 1998 11:41:24:930AM | 980220016 | Martin Greenwald | Good Shot RF, some H-modes Pellets at high power show no ne increase? Pellets fired at: Time Size Max Density .5 3 interferometer gives negative values (fringe skip) .6 2 .7 3 .8 2 .9 3 1. 2 |
| Feb 20 1998 11:50:33:870AM | 980220017 | Martin Greenwald | Good Shot Pellets fired at: Density with high power RF pumps out quickly Time Size Max Density .5 3 6 .6 2 5 .7 3 5 .8 2 4 .9 3 4 1.0 2 |
| Feb 20 1998 12:04:58:050PM | 980220018 | Martin Greenwald | Good Shot As before, shallow penetration and fast pump-out during RF Pellets fired at: Time Size Max Density .5 3 5 .65 3 5 .8 3 4 .9 2 3.5 .95 2 4 1. 2 |
| Feb 20 1998 12:16:06:660PM | 980220019 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 6 .65 3 6 .65 2 .8 3 7 .8 2 .9 2 plasma gone |
| Feb 20 1998 12:33:11:130PM | 980220020 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 6 .6 3 5 .6 2 .62 3 .62 2 .8 2 .9 3 |
| Feb 20 1998 12:47:14:870PM | 980220021 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 7 .6 3 6.5 .6 2 .62 3 12 .62 2 .8 2 .9 3 - |
| Feb 20 1998 12:53:23:360PM | 980220022 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 6.5 .6 3 6 .6 2 .62 3 12 .62 2 .8 2 .9 3 - |
| Feb 20 1998 01:04:51:450PM | 980220023 | Martin Greenwald | Good Shot RF power lowered to 1 MW Pellets fired at: Time Size Max Density .5 3 6.5 .6 3 4.5 .7 2 3.5 .8 3 4 .9 2 4 1 3 5 1.1 2 |
| Feb 20 1998 01:22:34:350PM | 980220024 | Martin Greenwald | Computer Crash, No Data. |
| Feb 20 1998 01:38:24:670PM | 980220025 | Martin Greenwald | Disruption Pellets fired at: Time Size Max Density .5 3 Disrupting Plasma .6 3 Plasma gone .65 2 Plasma gone .7 3 Plasma gone .75 2 Plasma gone .8 2 Plasma gone .85 3 Plasma gone |
| Feb 20 1998 01:47:58:450PM | 980220026 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 8.4 .6 3 4.5 .65 2 5.4 .7 3 8.3 .75 2 plasma gone .8 2 .85 3 |
| Feb 20 1998 02:01:01:320PM | 980220027 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 6.3 .6 3 5.2 .65 2 5.0 .7 2 3.7 (pellet doesn't show) .75 2 8.5 .85 3 Plasma Gone .95 3 |
| Feb 20 1998 02:07:57:130PM | 980220028 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 5.1 .6 3 2.9 .65 2 3.4 .7 2 No pellet .75 2 4.3 .85 3 Plasma gone .95 3 |
| Feb 20 1998 02:18:10:080PM | 980220029 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 7.0 .6 3 4.9 .65 2 5.8 .7 2 7.2 .8 3 Plasma gone .95 3 |
| Feb 20 1998 02:28:20:150PM | 980220030 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 7.0 .6 3 5.3 .65 2 5.2 .73 2 5.8 .83 3 Plasma Gone .98 3 |
| Feb 20 1998 02:39:50:350PM | 980220031 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 6.7 .6 3 3.9 .65 2 4.9 .7 1 5.1 .75 1 4.8 .8 1 5.6 .85 1 5.2 .9 1 5.0 |
| Feb 20 1998 02:52:19:610PM | 980220032 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 6.0 .6 3 4.4 .65 2 5.1 .69 1 5.4 .73 1 5.7 .77 1 6.3 .81 1 6.8 .85 1 Plasma gone .89 .5 .89 .5 .93 .5 .93 .5 |
| Feb 20 1998 03:04:00:680PM | 980220033 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 6.5 .6 3 5.1 .65 2 5.0 .69 1 5.3 .73 1 5.5 .77 1 5.7 .81 1 5.6 .85 1 5.5 .89 .5 5.9 .89 .5 .93 .5 Plasma gone .93 .5 |
| Feb 20 1998 03:12:20:400PM | 980220034 | Martin Greenwald | Early disruption at 0.5 s. No pellets entered plasma. |
| Feb 20 1998 03:23:46:230PM | 980220035 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 6.5 .6 3 3.3 .65 2 4.1 .69 1 4.1 .73 1 4.2 .77 1 5.6 .81 1 3.8 .85 1 Plasma gone .89 .5 .89 .5 .93 .5 .93 .5 |
| Feb 20 1998 03:34:35:010PM | 980220036 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 5.9 .6 3 3.3 .65 2 3.5 .69 1 3.4 .73 1 3.5 .77 1 4.7 .81 1 7.1 .85 1 Plasma gone .89 .5 .89 .5 .93 .5 .93 .5 |
| Feb 20 1998 03:47:06:620PM | 980220037 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 4.9 .6 3 4.0 .65 2 3.4 .69 1 3.2 .73 1 3.3 .77 1 3.4 .81 1 3.4 .85 1 4.0 .89 .5 .89 .5 4.7 .93 .5 .93 .5 Plasma gone - |
| Feb 20 1998 03:57:00:460PM | 980220038 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 6.0 .6 3 .6 2 8.4 .65 3 8.2 .7 2 8.1 .75 1 Plasma gone .83 1 .87 1 .91 1 .95 .5 .95 .5 .99 .5 .99 .5 |
| Feb 20 1998 04:10:32:760PM | 980220039 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 6.0 .6 3 4.3 .65 3 4.5 .7 2 4.8 .75 1 4.0 .79 1 5.0 .83 1 5.5 .87 1 5.0 .91 1 7.9 .95 .5 Plasma gone .95 .5 .99 .5 .99 .5 - |
| Feb 20 1998 04:23:04:730PM | 980220040 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 5.5 .6 3 4.2 .65 3 5.1 .7 2 9.3 .75 1 Plasma gone .79 1 .83 1 .87 1 .91 .5 .91 .5 |
| Feb 20 1998 04:39:54:700PM | 980220041 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 5.7 .55 .5 .55 .5 5.4 .6 3 .6 1 8.0 .65 3 7.7 .73 2 Plasma gone .79 1 .83 1 .87 1 |
| Feb 20 1998 04:50:40:860PM | 980220042 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 6.2 .6 2 3.7 .65 2 4.1 .7 2 2.8 (pellet doen't show) .75 2 6.0 .85 1 Plasma gone .9 1 1.0 1 1.05 1 |
| Feb 20 1998 04:59:17:900PM | 980220043 | Martin Greenwald | Good Shot Pellets fired at: Time Size Max Density .5 3 6.3 .6 2 3.8 .65 2 4.3 .7 2 (no pellet) .75 2 Plasma gone .85 1 .9 1 1.0 1 1.05 1 |
| Physics Operator Comments | |||
| Feb 19 1998 06:14:49:860PM | Steve Wolfe | Setting up for tomorrow's density limit run. Start from 980219021 (which used seg 1&3). Copy seg 4 -> seg 2. Change title to 800kA pellet target Turn off seg 3; Turn on Seg 4. Load it. | |
| Feb 20 1998 07:41:45:640AM | Steve Wolfe | Coldstart at 07:33. All ok. Note that there had already been a cycle, and there were scanner tests in progress, so there are some FNF messages after the coldstart points in the bitbus_server log. | |
| Feb 20 1998 07:45:36:590AM | Steve Wolfe | Run Plan for Friday, 980220 MP166 Density Limits (with pellets) SL: Greenwald PO: Wolfe ECDC overnight in D2. Engineering setup: ------------------ PF Power supplies as on 980217005. TF on hybrid control with current limit 165kA Gas: B-top 6psi D2 Hybrid enabled B-side lower 1psi Ar Hybrid enabled K-side 30psi D2 Hybrid enabled Run Plan -------- Start with a fiducial (e.g. 980217005). The object of the run is to test density limits with pellet injection. We'll try to explore both the L-mode disruptive limit and the H/L transition limit. Given the limitations on power, the H-mode work will probably have to be at 0.6 MA. We could do the L-mode work at .8 or 1.0 MA - the higher value gives us more headroom but bigger disruptions. We should probably start at 0.8 Bt = 5.65 to give us a chance of getting Te profiles. 1. starting with OH plasmas, Ip=.8 MA, ne targets ~ 1.5-2 e20 The pellet size, number and timing will be varied to give a maximum density in quasi-steady state. 2. next turn on RF heating ~ 2.5 MW, Ip= .8 MA, ne targets ~ 1.5-2 e20 The pellet size, number and timing will be varied to give a maximum density in quasi-steady state. We may get intermittent H-modes until the density gets above 3-4 e20 3. As above but at .6 MA, In this case the density limit is down to 4e20 where we can sustain H-modes | |
| Feb 20 1998 08:10:08:870AM | Steve Wolfe | Modify segment 2 to have TF current = -157000. Load/into model (before shot 2). Still using seg 4 for fiducial shot. Must remember to copy TF trace to seg 1 for main experiments. | |
| Feb 20 1998 07:33:46:610AM | 980220001 | Steve Wolfe | Shot 1: Scanner Test. No power. |
| Feb 20 1998 08:34:17:240AM | 980220002 | Steve Wolfe | shot 2: fiducial (in seg 4). fizzle. bd at 7.2msec, br is positive, bz negative. Next shot: Br from .0055 to .005; IC_ef4 from -1335 to -1330. |
| Feb 20 1998 08:46:54:210AM | 980220003 | Steve Wolfe | shot 3: fiducial (in seg 4). plasma . earlier bd, br now looks negative, bz a little better? Fiducial looks good, 2pi<300kW strike is on the floor before .6sec or so. Next shot: go to seg2, TF->157kA, ZXL up by .01 (from -.015 to -.005) |
| Feb 20 1998 08:54:48:770AM | 980220004 | Steve Wolfe | shot 4: go to seg2, TF->157kA, ZXL up by .01 (from -.015 to -.005) plasma. 5.7T, 2pi < 250kW, 1.3e13neut /sec, Wmhd=116kJ Zsout up to -50 after .43sec next shot: repeat |
| Feb 20 1998 09:04:16:200AM | 980220005 | Steve Wolfe | shot 5: repeat. Rf is doing something. plasma. higher rf power 2.8MW, 2pi up to 350kW. Rn=2.4e13, Wmhd=142kJ. Next shot: pellet on, RF off. |
| Feb 20 1998 09:19:43:410AM | 980220006 | Steve Wolfe | shot 6: pellet on, RF off. plasma disrupts at 1.14sec. After 4th pellet. nl4 got to 5e20! Earlier pellets had smaller increments. TS density is gtting blown away by the pellets . |
| Feb 20 1998 09:35:56:490AM | 980220007 | Steve Wolfe | shot 7: G wil use a smaller pellet for #4 this time. NO PCS changes; it will probably fizzle. plasma. to 1.4sec, made it through all four pellets. "Four p-modes" - [G] TCI program bombed, hung cycle. Irby recovered it. |
| Feb 20 1998 09:48:18:590AM | 980220008 | Steve Wolfe | shot 8: smaller pellets, closer together. plasma disrupts at 1.08sec, shortly after 4th pellet. Current had turned over, Vsurf > 3V. Radiation up. startup looks ok, although Br is now quite negative. I won't tweak until I lose one. |
| Feb 20 1998 09:56:14:030AM | 980220009 | Steve Wolfe | shot 9: repeat (shudder!) plasma disrupts at 1.11sec Little chunks out of the current at each pellet, the last one doesn't recover. First pellet looks like a fragment. Next time: space the last one out a little more. |
| Feb 20 1998 10:05:35:730AM | 980220010 | Steve Wolfe | shot 10: space the last one out a little more. plasmacide at 1.04sec |
| Feb 20 1998 10:20:33:070AM | 980220011 | Steve Wolfe | shot 11: slightly different pellet timing plasma to 1.89 sec, mutiple mini-disruptions before final end. |
| Feb 20 1998 10:30:22:750AM | 980220012 | Steve Wolfe | shot 12: slightly different (again) pellet timing plasma disrupts at .89 sec. The death pellet is actually hard to see on the density, but is there on Halpha and CII. Next shot: rf on at .55sec |
| Feb 20 1998 10:58:24:240AM | 980220013 | Steve Wolfe | shot 13: rf on at .55sec. plasma to 1.41sec, first pellet was before rf (I thought it would be after). ef1L crowbars at 1.48, then tf crowbar at about 1.6sec. Vinnie says that the new instrumentation on the EF1 confirms this was a false firing of the self-powered circuit. |
| Feb 20 1998 11:08:11:060AM | 980220014 | Steve Wolfe | shot 14: do it again. plasma soft landed at 1.67sec. No pellets this time; Greenwald fumbled. RF ran fine, Prf =2.3MW, EDA h-mode. One Mo injection at .71sec |
| Feb 20 1998 11:22:23:080AM | 980220015 | Steve Wolfe | shot 15: try again with pellets. plasma to 1.298 sec one transmitter failed immediately, so only 1MW of RF. only two pellets (.51 and .6sec). Slow density rise during the RF in L-mode. Shark-fin at the end after rf turns off. |
| Feb 20 1998 11:40:13:840AM | 980220016 | Steve Wolfe | shot 16: repeat, hopefully with both transmitters. plasma to .96sec. next to the last one tripped on xmitter. 2.5MW while it lasts. Wmhd close to 100kJ at maxima. Slight hesitation in current rise. Bz looks a bit positive. Don't tweak yet. |
| Feb 20 1998 11:49:09:160AM | 980220017 | Steve Wolfe | shot 17: reduce RF to 2MW (and retune) to try to elimiate screen overcurrent trips. plasma. looked like h-modes on the tv. disrupted at 1.09sec. RF hanging in there with some trips at the pellets. bd a little earlier, bz looks better, br a bit negative. |
| Feb 20 1998 12:04:54:880PM | 980220018 | Steve Wolfe | shot 18: pellets closer together. Only the first one is making it to the center. Later ones pump out very fast, but they deposit pretty far out. plasma to 1.09sec. It's still killing the current at the end. |
| Feb 20 1998 12:17:59:770PM | 980220019 | Steve Wolfe | shot 19: trying to double up on pellets during rf to improve penetration. plasma disrupts at .86, bite out of the current at .82 from which it never recovers. |
| Feb 20 1998 12:35:30:690PM | 980220020 | Steve Wolfe | shot 20: and again. plasma to .94sec, rf at 2.3MW or so. looks like a slush ball or gas puff instead of a pellet at .8sec slight hesitation, br looking negative again. |
| Feb 20 1998 12:45:47:240PM | 980220021 | Steve Wolfe | shot 21: try that one again plasma disrupts at .664 sec. Way to go Martin! nl4 says 7e20 |
| Feb 20 1998 12:52:28:800PM | 980220022 | Steve Wolfe | shot 22: He wants to try it again. And he did. plasma to .665, it's reproducible! Next shot Martin wil back off and RF to 1MW |
| Feb 20 1998 01:13:48:640PM | 980220023 | Steve Wolfe | shot 23: Less agressive pellets, rf to 1MW. plasma to .98 sec, got 1MW with a few trips. max density on first pellet nl4=4.5e20 bad hesitation, bz too positive |
| Feb 20 1998 01:23:24:790PM | 980220024 | Steve Wolfe | shot 24: Now try closing them up plasma disrupts early. DAQA Crashed. No data on this one. |
| Feb 20 1998 01:36:03:490PM | 980220025 | Steve Wolfe | shot 25: Retry with computers. plasma disrupts at .51sec. There was a brick at .486, just before the first pellet. |
| Feb 20 1998 01:46:29:980PM | 980220026 | Steve Wolfe | shot 26: And try again. plasma disrupts at .74 sec nl4 gets to 4.5e20 or so. Martin says we're going in the right direction ! |
| Feb 20 1998 01:57:27:750PM | 980220027 | Steve Wolfe | shot 27: Try stepping up more gently. (smaller sledge hammer) plasma disrupts at .765sec. nl4 = 5e20. |
| Feb 20 1998 02:10:19:950PM | 980220028 | Steve Wolfe | shot 28: and try this one again. Martin actually claims the previous one had an injection before the last pellet. plasma disrupts at .781 sec TRAQ1 data corrupted. I'll have to re-run efit. density didn't seem to get very high on that one. |
| Feb 20 1998 02:17:05:600PM | 980220029 | Steve Wolfe | shot 29: Still tweaking the pellet timing. And the plasma is still disrupting (at 733) Martin thinks he's sneaking up on it. |
| Feb 20 1998 02:31:26:400PM | 980220030 | Steve Wolfe | shot 30: Still tweaking the pellet timing. plasma disrupts at .781 possible h-mode at .58 ? |
| Feb 20 1998 02:37:51:420PM | 980220031 | Steve Wolfe | shot 31: Still tweaking the pellet timing. plasma to 1.06 sec; that's beginning to look long! 8 pellets on this shot. |
| Feb 20 1998 02:52:07:300PM | 980220032 | Steve Wolfe | shot 32: Moving the little ones closer together and adding two more at the end. plasma to .82sec. The small pellets ratchet the density up to nl4=4e20. This actually looks like we're doing an experiment. |
| Feb 20 1998 03:01:03:790PM | 980220033 | Steve Wolfe | shot 33: repeat. Martin promises to change the current after this one, if it looks the same. plasma to .92sec nl4 to just over 3e20, until the last one. Next shot, 600kA. |
| Feb 20 1998 03:38:58:500PM | 980220034 | Steve Wolfe | shot 34: change Ip to 600kA. First PCS change since 8:40 something this morning. plasma died early right at 0.5sec. Big drop in current at .11. Huge injection at .116 almost killed it. It dies of a big vertical oscillation. li is 1.9, n/ncrit=1.39. I think it was still suffering from the injection. Try again and see if it does it twice. |
| Feb 20 1998 03:32:18:330PM | 980220035 | Steve Wolfe | shot 35: repeat try at 600kA. plasma to .81 sec, nl4 to 3.6e20 on the first pellet, then back to about the same on the 6th. outer gap over 2cm. n/ncrit=1.2, oleft=2cm |
| Feb 20 1998 03:36:00:760PM | 980220036 | Steve Wolfe | shot 36: clearin from -.008 to -.013 plasma to .836 sec looks similar to last one. Next shot: 1MA |
| Feb 20 1998 03:47:58:650PM | 980220037 | Steve Wolfe | shot 37: Go to 1MA, clearin back from -.013 to -.008 plasma to .92 sec, density is low (2.8e20 nl4) at disruption, but temperature is down to 800ev or so. radiation is increasing to 2MW. loop voltage over 2V. |
| Feb 20 1998 03:58:02:190PM | 980220038 | Steve Wolfe | shot 38: increasing the early pellets. plasma to .72sec, nl4 to 4.9e20. Again the current turns over and prad goes up. |
| Feb 20 1998 04:09:15:840PM | 980220039 | Steve Wolfe | shot 39: backing off a bit. plasma to .91sec, this one lasted longer anyway. Still disrupting at nl4 < 3e20. |
| Feb 20 1998 04:30:41:350PM | 980220040 | Steve Wolfe | shot 40: slight change plasma disrupts at .72sec again. 2pi goes to 7MW on the last thing, possibly a brick. That one blew the ion gauge (IGT). A brief delay while Joe figures out how to disable the gas fault. |
| Feb 20 1998 04:38:37:130PM | 980220041 | Steve Wolfe | shot 41: delay the .71 pellet some. Gas fill fault clears. Still not getting a ready bit from TORVAC; Bypass it. Early disruption at .68sec. He put in one extra small pellet earlier. |
| Feb 20 1998 04:50:03:210PM | 980220042 | Steve Wolfe | shot 42: remove the earlier small pellet (I guess). plasma disrupts at .78sec, nl4=3.4e20 |
| Feb 20 1998 04:59:26:360PM | 980220043 | Steve Wolfe | shot 43: turn off the Argon. Change the pellet timing again. plasma disrupts at .78sec, density is only 2.2e20 unless TCI lost fringes. |
| Feb 20 1998 05:08:54:240PM | 980220044 | Steve Wolfe | Shot 44: Scanner test. No power |
| Feb 20 1998 05:35:34:180PM | 980220044 | Steve Wolfe | After the run: Tommy checked out ITG and got it going again. Possibly a loose connector, the filament is ok. We now have one good filament on ITG and one good filament on the backup gauge. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 07:23:12:830AM | Test | Ok | scanner test |
| 2 | 08:25:08:750AM | Plasma | Ok | |
| 3 | 08:37:07:400AM | Plasma | Ok | |
| 4 | 08:47:50:240AM | Plasma | Ok | |
| 5 | 08:57:37:890AM | Plasma | Ok | |
| 6 | 09:10:04:700AM | Plasma | Ok | |
| 7 | 09:22:23:900AM | Plasma | Ok | |
| 8 | 09:40:07:260AM | Plasma | Ok | |
| 9 | 09:51:31:770AM | Plasma | Ok | |
| 10 | 10:03:02:300AM | Plasma | Ok | |
| 11 | 10:15:06:900AM | Plasma | Ok | |
| 12 | 10:25:09:310AM | Plasma | Ok | |
| 13 | 10:43:10:570AM | Plasma | Bad | ef1l cbar |
| 14 | 11:03:07:720AM | Plasma | Ok | |
| 15 | 11:13:57:690AM | Plasma | Ok | |
| 16 | 11:27:05:630AM | Plasma | Ok | |
| 17 | 11:42:48:260AM | Plasma | Ok | |
| 18 | 11:58:28:870AM | Plasma | Ok | |
| 19 | 12:10:56:050PM | Plasma | Ok | |
| 20 | 12:25:00:010PM | Plasma | Ok | |
| 21 | 12:39:44:170PM | Plasma | Ok | |
| 22 | 12:50:07:660PM | Plasma | Ok | |
| 23 | 01:00:27:060PM | Plasma | Ok | |
| 24 | 01:13:12:370PM | Plasma | Ok | |
| 25 | 01:30:58:700PM | Plasma | Ok | |
| 26 | 01:42:02:050PM | Plasma | Ok | |
| 27 | 01:52:11:330PM | Plasma | Ok | |
| 28 | 02:02:07:870PM | Plasma | Ok | |
| 29 | 02:12:33:950PM | Plasma | Ok | |
| 30 | 02:23:31:740PM | Plasma | Ok | |
| 31 | 02:33:56:490PM | Plasma | Ok | |
| 32 | 02:46:39:550PM | Plasma | Ok | |
| 33 | 02:57:29:550PM | Plasma | Ok | |
| 34 | 03:07:24:500PM | Plasma | Ok | |
| 35 | 03:17:49:030PM | Plasma | Ok | |
| 36 | 03:28:58:210PM | Plasma | Ok | |
| 37 | 03:40:14:940PM | Plasma | Ok | |
| 38 | 03:52:27:330PM | Plasma | Ok | no faults/plasma |
| 39 | 04:02:53:460PM | Plasma | Ok | no faults/plasma |
| 40 | 04:18:09:910PM | Plasma | Ok | no faults/plasma |
| 41 | 04:34:52:520PM | Plasma | Ok | no faults/plasma |
| 42 | 04:44:40:990PM | Plasma | Ok | no faults/plasma |
| 43 | 04:54:44:650PM | Plasma | Ok | no faults/plasma |
| 44 | 05:06:56:410PM | Test | Ok | tf scanner test |