| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Martin Greenwald |
| Physics operator(s): | Unknown |
| Engineering operator(s): | Unknown |
| Engineering Operator Run Comment |
| Omic confinment |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:11:493PM |
| Author: To Be Determined |
| Summary for Run 941207 M. Greenwald - 12/7/94 The purpose of the run was to make as close a comparison as possible between transport scaling on C-Mod and Alcator-C. To this end, we ran nearly circular plasmas; kappa = 1.1, with minor radius, a = .18 m and major radius, R = .63 m. At our nominal Bt = 5.3 this gave a field at the magnetic axis above 5.5. For comparison, Alcator-C had a = .17(and .165) R = .64 m and of course kappa = 1. Most Alcator-C data was with fields above 6T. With this geometry we scanned density and Ip to cover as much of the operating space as possible. The currents ranged from .25 (q=6) to .55 MA (q=2.8). Line averaged densities ran from .7 to 2.4 e20. Typically slow ramps were applied to give us more points on the density scans. A large fraction of the shots are suitable for analysis. Good shots with very low elongation (< 1.2) were: SHOT ne_average Ip 941207006 1.2 .4 941207007 1.2 .4 941207009 0.7 -> 1.3 .4 941207010 0.6 -> 1.45 .4 941207011 1.7 -> 2.4 .38 941207029 1.0 -> 1.5 .4 941207013 1.7 -> 2.4 .56 941207014 1. -> 1.2 .55 941207015 1.5 -> 1.7 .56 941207016 1.0 .56 941207019 1.0 .54 941207020 0.8 -> 0.9 .54 941207022 0.7 -> 1.3 .29 941207024 0.7 -> 1.4 .25 941207025 1.0 -> 2.0 .3 - .2 941207026 1.4 -> 1.8 .25 941207028 0.7 -> 1.4 .25 Good shots at higher elongation included 941207001 941207002 941207003 941207004 941207005 Analysis to follow. |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:36:52:363PM |
| Author: To Be Determined |
| Physop Summary for 941207 Circular Alcator C Simulations. Generally obtained good coverage of currents from 200kA to 550kA circular R=.62, a=.18m Alcator C like. With densities nL from 2 to 10 e19. Shot Start at 941201020 1 Pla No changes. Looked good. Set afterwards as follows Ip 360kA RCUR 0.61m Clearin -0.12m (Wavegen overflow. Reduced factor by 2, reduced controller rate) RXL -0.045m (largest possible without changing factor) ZXL -0.05m RXU -0.045m RXL +0.05m NL 0.4e20. 2 Pla Clearin not reaching its demand. Current overshot slightly. EF2 asymmetry. Raised gain on CLEARIN to maximum. Asymmetry in ZXU/ZXU gains fixed. 3 Pla Installed Integral gain in Clearin. Set to 100s^-2 Lowered voltage programmed on OH1/2, EF3, EF2 to help the overshoot. 4 Pla Some runaways. It looks in PCS as if the integrator on clearin 'did not take'. This is the PCS ghost. Fill to 1.8e-5 Doubled the OH2 part of the Clearin controller. Put in -10000 offset in CLEARIN. ZXU to 0.06m 5 Pla EF2s railed. Disrupted late. The offset was the wrong sign. ZXU symmetry was better, not quite enough. ZXU to +0.07. +10000 on Clearin. 6 Pla Integral gain appeared to "take". EF2s nearly symmetric and not railing. Nice circular plasmas. But with major radius about 0.65m, even though the predictor is reading .62m. This appears to be a calibration problem. Offset on RCUR to 4000 Set drawn RCUR to .59m. Required factor and rate to be dropped to .75. 7 Pla Got the RCUR predictor value we asked for (.59 -- really more like .62). Elongation increased to 1.15. Drawn NL ramp from 2-4e19 Drawn Clearin to -.14 (from -.12) Drawn ZXU/ZXL maintained during down ramp, gains to 4 from 1.8. 8 PSdud No EF3 current. 9 Pla A fine shot. Density ramps a little slowly. Programmed lower density early, and reduced the V pulsegas program. Slight tweak to early OH1 voltage. 10 Pla Density stayed up later as asked but did not stay low early. Draw NL ramp from 4-8e19. 11 Pla Got the density we asked for nearly. A big puff when feedback turns on at .174s. Ip to 550kA NL feedback turned on at 0.1s. 12 Fiz Gassed out. Fill to 1.5e-5. 13 Pla OK. EF2s railed. Plasma slightly further in. Got 550kA. RCUR offset to 9000 Drawn RCUR to .61m NL ramp 2-4. 14 Pla Controllers lose it starting at 0.8s. Not clear why. NL ramp 3-6 15 Pla Suggestion that EF1 is voltage clipped. And OH2 later. NL downramp 2.5-1e19 16 Pla Disruption at end 400kA. Density did not fall. NL ramp 3.5-12.e19. 17 Pla Disrupt @0.43 sec too much gas. NL to 1.e-19. 18 Fiz No burn through. Repeat. 19 Pla Density did not reach the low values desired. Lower the pulse gas V a lot. 20 Pla nL 2.5e19. Ip to 250kA. Crowbar form .12s to .1s. 21 Pla Runaways. nl=1e19. Current overshoots. Shape ok. ECE non-thermal. Crowbar to 0.07s pulse gas 2 ms earlier (-.07 vs -.05s). nL drawn 2-5e19 22 Pla Crowbar to 0.055s. RCUR offset to 11000. Ip offset to 20000. Ip drawn to 230. Tweaked the drawn nL. 23 Pla Disrupts at 0.13s. OH2 voltage demands caused by earlier crowbar etc. throws the plasma away vertically before EFC comes on. RCUR offset to 10000 Crowbar to 0.07s. 24 Pla OK we accept the current overshoot for now. Draw NL 4-8e19. 25 Pla Disrupts at 1.1s. Raise Ip gain to 9.5 Draw nL 4-6e19. 26 Pla OK. Minor disruption at 1 sec. Survived. 27 Fiz 28 Pla nL obtained: 2-5e19. Reload shot 11. Lowered nL ramp to 2-6e19. 29 Pla Forgot to ask for the crowbar later, butit worked OK. Scorecard: Shot,Duration(s),Ipmax(MA) Shot,Duration(s),Ipmax 1 1.473 0.641 2 1.380 0.466 3 1.377 0.455 4 1.378 0.424 5 1.285 0.435 6 1.360 0.427 7 1.360 0.419 8 0.000 0.016 9 1.364 0.406 10 1.364 0.393 11 1.310 0.399 12 0.000 0.024 13 1.356 0.566 14 1.191 0.559 15 1.354 0.564 16 1.132 0.554 17 0.410 0.590 18 0.000 0.026 19 1.144 0.556 20 1.128 0.546 21 1.400 0.365 22 1.338 0.311 23 0.136 0.280 24 1.293 0.321 25 1.118 0.311 26 1.298 0.300 27 0.000 0.029 28 1.326 0.321 29 1.368 0.396 Finished summary for 941207 Total of 29 shots. 29 shots. 25 plasmas. 3 fizzles. 1 duds. Fizzle = gt 17 lt 50kA. |
| Session Leader Comments | |||
| Dec 7 1994 09:06:25:780AM | Martin Greenwald | Ohmic Confinement Run
Intention is to run Alcator-C like discharges with kappa = 1 a = .17 and R = .61 Then do ne and Ip scans | |
| Dec 7 1994 09:08:12:800AM | 941207001 | Martin Greenwald | Repeat of shot 941201020 - just for startup
|
| Dec 7 1994 09:26:58:090AM | 941207001 | Martin Greenwald | First attemp at lower kappa; achieved
kappa = 1.2 a = .2 R = .66 Ip = .4 nel = .4 |
| Dec 7 1994 09:47:40:630AM | 941207001 | Martin Greenwald | kappa = 1.2
a = .2 R = .66 Ip = .4 nel = .4 |
| Dec 7 1994 10:16:13:360AM | 941207002 | Martin Greenwald | kappa = 1.2
a = .2 nel = .4 ip = .4 |
| Dec 7 1994 10:16:31:360AM | 941207003 | Martin Greenwald | kappa = 1.2
a = .2 nel = .4 ip = .4 |
| Dec 7 1994 10:16:48:680AM | 941207004 | Martin Greenwald | kappa = 1.2
a = .2 nel = .4 ip = .4 |
| Dec 7 1994 10:24:13:220AM | 941207005 | Martin Greenwald | kappa = 1.3
a = .2 r = .65 nel = .4 ip = .4 |
| Dec 7 1994 10:40:43:590AM | 941207006 | Martin Greenwald | kappa = 1.07
a = .21 r = .66 nel = .4 ip = .4 |
| Dec 7 1994 11:02:19:660AM | 941207007 | Martin Greenwald | kappa = 1.2
a = .18 r = .63 nel = .45 ip = .4 |
| Dec 7 1994 11:21:24:880AM | 941207008 | Martin Greenwald | Dud - Power Supply problem
|
| Dec 7 1994 11:50:51:390AM | 941207009 | Martin Greenwald | kappa = 1.1
a = .18 r = .63 ne_av = .7 -> 1.3 ip = .4 |
| Dec 7 1994 12:00:34:710PM | 941207010 | Martin Greenwald | kappa = 1.1
a = .18 r = .63 ne_av = .6 -> 1.45 ip = .4 |
| Dec 7 1994 12:23:54:760PM | 941207010 | Martin Greenwald | kappa = 1.1
a = .18 r = .63 ne_av = 1.7 -> 2.4 ip = .38 |
| Dec 7 1994 12:33:23:880PM | 941207011 | Martin Greenwald | kappa = 1.1
a = .18 r = .63 ne_av = 1.7 -> 2.4 ip = .38 |
| Dec 7 1994 12:56:59:820PM | 941207013 | Martin Greenwald | kappa = 1.15
a = .17 r = .62 ne_av = 1.7 -> 2.4 ip = .56 |
| Dec 7 1994 01:12:14:900PM | 941207014 | Martin Greenwald | kappa = 1.1
a = .18 r = .62 ne_av = 1. -> 1.2 ip = .55 |
| Dec 7 1994 01:30:56:510PM | 941207015 | Martin Greenwald | kappa = 1.1
a = .18 r = .63 ne_av = 1.5 -> 1.7 ip = .56 |
| Dec 7 1994 01:51:52:910PM | 941207016 | Martin Greenwald | kappa = 1.1
a = .18 r = .63 ne_av = 1. ip = .56 |
| Dec 7 1994 02:45:31:250PM | 941207019 | Martin Greenwald | kappa = 1.1
a = .18 r = .63 ne_av = 1.0 ip = .54 |
| Dec 7 1994 02:44:53:620PM | 941207020 | Martin Greenwald | kappa = 1.1
a = .18 r = .63 ne_av = 0.8 0.9 ip = .54 |
| Dec 7 1994 03:05:02:690PM | 941207021 | Martin Greenwald | Dominated by hard x-rays
kappa = 1.1 a = .18 r = .63 ne_av = 0.3 ip = .54 |
| Dec 7 1994 03:22:58:110PM | 941207022 | Martin Greenwald | Dominated by hard x-rays
kappa = 1.1 a = .185 r = .64 ne_av = 0.7 - 1.3 ip = .29 |
| Dec 7 1994 03:52:38:340PM | 941207024 | Martin Greenwald | Dominated by hard x-rays
kappa = 1.1 a = .185 r = .64 ne_av = 0.7 - 1.4 ip = .25 |
| Dec 7 1994 04:22:49:110PM | 941207025 | Martin Greenwald | Dominated by hard x-rays
kappa = 1.1 a = .185 r = .64 ne_av = 1.4 - 1.8 ip = .3 - .2 |
| Dec 7 1994 04:23:06:880PM | 941207025 | Martin Greenwald | Dominated by hard x-rays
kappa = 1.1 a = .185 r = .64 ne_av = 1.0 - 2.0 ip = .3 - .2 |
| Dec 7 1994 04:23:30:880PM | 941207026 | Martin Greenwald | Dominated by hard x-rays
kappa = 1.1 a = .185 r = .64 ne_av = 1.4 - 1.8 ip = .25 |
| Dec 7 1994 04:48:52:290PM | 941207028 | Martin Greenwald | Dominated by hard x-rays
kappa = 1.1 a = .185 r = .64 ne_av = .8 - 1.4 ip = .25 |
| Dec 7 1994 05:03:34:970PM | 941207029 | Martin Greenwald | Dominated by hard x-rays
kappa = 1.1 a = .185 r = .64 ne_av = 1. - 1.5 ip = .4 |
| Physics Operator Comments |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:04:22:190AM | Plasma | Ok | No Faults. |
| 2 | 09:16:22:910AM | Plasma | Ok | No Faults. |
| 3 | 09:36:51:820AM | Plasma | Ok | no faults |
| 4 | 09:56:11:760AM | Plasma | Ok | No faults |
| 5 | 10:15:00:140AM | Plasma | Ok | No faults. |
| 6 | 10:31:00:560AM | Plasma | Ok | No faults. |
| 7 | 10:51:01:360AM | Plasma | Ok | No faults. |
| 8 | 11:10:37:940AM | Plasma | Ok | No faults |
| 9 | 11:19:48:600AM | Plasma | Ok | No faults |
| 10 | 11:47:47:460AM | Plasma | Ok | No faults. |
| 11 | 12:06:26:050PM | Plasma | Ok | No faults |
| 12 | 12:35:21:150PM | Plasma | Ok | no faults |
| 13 | 12:45:49:510PM | Plasma | Ok | no faults |
| 14 | 01:02:38:620PM | Plasma | Ok | no faults |
| 15 | 01:22:51:230PM | Plasma | Ok | no faults |
| 16 | 01:37:53:350PM | Plasma | Ok | no faults |
| 17 | 01:50:59:230PM | Plasma | Ok | no faults |
| 18 | 02:05:21:140PM | Plasma | Ok | fizzle, no faults |
| 19 | 02:15:57:280PM | Plasma | Ok | no faults |
| 20 | 02:35:53:630PM | Plasma | Ok | no faults |
| 21 | 02:49:56:420PM | Plasma | Ok | no faults |
| 22 | 03:10:22:140PM | Plasma | Ok | no faults |
| 23 | 03:26:16:950PM | Plasma | Ok | no faults |
| 24 | 03:42:08:470PM | Plasma | Ok | no faults |
| 25 | 03:57:37:330PM | Plasma | Ok | no faults |
| 26 | 04:13:38:810PM | Plasma | Ok | no faults |
| 27 | 04:29:28:150PM | Plasma | Ok | no faults |
| 28 | 04:40:36:780PM | Plasma | Ok | no faults |
| 29 | 04:58:59:640PM | Plasma | Ok | no faults |