| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Chuck Kessel |
| Physics operator(s): | Ian Hutchinson,Steve Wolfe,Ian Hutchinson |
| Engineering operator(s): | Bill Parkin,Bill Cochran,Bill Byford |
| Engineering Operator Run Comment |
| MP577 ITER-like Discharge Rampup Studies |
| Session Leader Plans |
| Entered: Sep 10 2009 07:21:17:040PM |
| Author: Chuck Kessel |
| MP577 ITER-like Discharge Rampup Studies
Goal: Examine various current rampup scenarios in the ITER-like configuration to establish dependences of volt-second consumption, li evolution, and PF coil responses. Recover discharge from MP576 Improve ITER-like Discharge Startup with any startup improvements and early divert time, 1090903033 (remove ICRF heating in ramp). 1) establish ohmic rampup baseline (5 shots) a. rampup Ip in 500-600 ms b. nL targeted to 1.0 x 10^20 /m2 at end of Ip ramp c. plasma elongation in flattop is 1.8, q95 steady in flattop â?? 3.2, Ip = 1.3-1.35 MA d. flattop duration sufficiently long for current profile relaxation, avoid late time disruptions e. standard C-Mod rampdown duration 0.5 s, power termination. f. ICRF <4 MW injected at end of rampup to produce flattop H-mode 2) utilizing density nL â?¤ 1x1020 /m2 and remaining in L-mode, inject ICRF power during the rampup a. 1.0 MW fixed power beginning at or about divert time (2 shots) b. 2.0 MW fixed power beginning at or about divert time (2 shots) c. 3.0 MW fixed power beginning at or about divert time (2 shots) d. step ramp 1.0 to 2.0 MW, beginning at or about divert time, step ½ way up ramp (2 shots) e. step ramp 1.0 to 2.0 to 3.0 MW, beginning at or about divert time, 1st step1/3 way up ramp, and 2nd step at 2/3 way up ramp (2 shots) 3) utilizing the density dependence for H-mode transition, raise density to value where H-mode transitions are reliable in rampup (2 shots) a. inject 2.0+ MW at 400 ms (2 shots) b. inject 2.0+ MW at 300 ms (2 shots) c. inject 2.0+ MW at 200 ms (2 shots) d. inject 2.0+ MW at or about divert time (2 shots) 4) density scan with specific ohmic and ICRF L-mode discharges provided above, adjust densities to avoid consistent loss of coupled power to plasma a. nL = 0.5x1020 /m2, ohmic and ICRF 1-2-3 MW stepped (2 shots) b. nL = 1.5x1020 /m2, ohmic and ICRF 1-2-3 MW stepped (2 shots) c. nL = 2.0x1020 /m2, ohmic and ICRF 1-2-3 MW stepped (2 shots) |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Sep 14 2009 08:13:27:423AM |
| Author: Chuck Kessel |
| MP577 ITER-like Discharge Rampup Studies
The run day had some difficulties with computer/data problems, but overall significant progress was made. There were a number of injections causing very large radiated power. A baseline discharge was established with Ip = 1.3 MA, Bt = 5.4 T, q95 = 3.0, divert time of 100 ms, kappa = 1.75, Ip rampup time of 550 ms, and nL = 1.0e20 /m2 at 550 ms. The flattop was made long enough for the current profile to relax. 3 MW of ICRF power was injected at the end of the Ip rampup to make H-modes in flattop Early ICRF heating was done with 1.0 MW and 2.0 MW at 120 ms. The 2.0 MW case showed excessive radiated power, so 1.0 MW became the reference for the earliest heating. Stepped up ICRF power was examined, with 1.0 MW at 120-250 ms, 2.0 MW at 250-550 ms, showing good behavior, with low radiation. Cases with 1.0 MW at 120-250 ms, 2.0 MW at 250-375 ms, and 3.0 MW at 375-550 ms showed some difficulties at 3.0 MW. The 1.0 MW and 2.0 MW step worked the best. The ICRF appeared to get better the more time we used it, presumably conditioning after the boronization. With the 1.0-2.0 MW step power trajectory the density was increased to 1.25e20, and 1.35e20. Higher values did not help H-mode access, which was expected. There was only one discharge with H-mode in the rampup at about 400 ms. The ICRF heating reduced the OH1 current swing, but appears to change li little, unless an H-mode is produced. This will test the simulations projections for ITER. Other PF coil responses will be examined as well. Considerable effort was spent improving the discharge scenario, with smoother trajectories. The earliest divert occurred at 70 ms. Large bore plasmas are routinely produced by the earliest EFIT time at 60 ms. The li trajectoreis in the earliest times are becoming very uniform indicating a reproducible startup. |
| Physics Operator Summaries |
| Entered: Sep 11 2009 05:12:58:503PM |
| Author: Ian Hutchinson |
| MP577 ITER like ramp up.
Substantial time was lost because of MDS hangs. It was trivial to get the Ip ramp to 1.3MA in 0.5s. The early part of the run was rather free from disruptions, but later with RF there were a substantial number of disruptions, all caused by radiative events. Boronization recovery was almost immediate. Post disruption fizzles were experienced quite often. Early diversion was improved as a background task. Shot 30 has diversion at 70ms, but needs some more tweaking to the radial position because its oscillations make the plasma dangerously elongated at ~0.1s (up to 1.7 on the inward Rcur swing). My recommendation for controlled rampup early diversion is shot 30 but with adjustments to the voltages to reduce the Rcur swing and increase of fill puff. Scorecard ---------
Shot,Duration(s),Ipmax(MA),Result Shot,Duration(s),Ipmax,Result
| 01 0.535 0.031 Fizzle | 02 0.000 0.002 Dud |
| 03 0.000 0.002 Dud | 04 1.559 1.287 Plasma |
| 05 2.300 1.289 Plasma | 06 2.300 1.291 Plasma |
| 7 No Ip | 8 No Ip |
| 9 No Ip | 10 2.300 1.300 Plasma |
| 11 2.300 1.308 Plasma | 12 2.300 1.308 Plasma |
| 13 0.828 1.107 Plasma | 14 2.300 1.301 Plasma |
| 15 1.022 1.296 Plasma | 16 0.522 0.041 Fizzle |
| 17 2.300 1.305 Plasma | 18 2.300 1.303 Plasma |
| 19 2.300 1.302 Plasma | 20 0.592 1.203 Plasma |
| 21 0.530 0.041 Fizzle | 22 0.864 1.269 Plasma |
| 23 0.528 0.043 Fizzle | 24 2.300 1.307 Plasma |
| 25 1.274 1.354 Plasma | 26 2.300 1.299 Plasma |
| 27 0.527 0.047 Fizzle | 28 1.018 1.363 Plasma |
| 29 0.863 1.239 Plasma | 30 2.300 1.289 Plasma |
Date 1090911: 30 shots. 20 plasmas. 5 fizzles. 2 duds. 3 System Error.
(Plasma = Ip gt 60.0 kA Dud = H_alpha lt 0.40 V)
Total plasma duration: 38.26 s (exceeding -3 kA)
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| Session Leader Comments | |||
| Sep 11 2009 10:27:26:027AM | 1090911005 | Chuck Kessel | good shot....ohmic full discharge thru rampdown
Ip = 1.3 MA at 500 ms divert at about 120 ms rampdown begins at 1.2 s |
| Sep 11 2009 10:44:34:527AM | 1090911006 | Chuck Kessel | super shot....ohmic full discharge thru rampdown, smooth trajectories all around
maximum kappa is going to be 1.75, maybe higher with H-modes later li shows very good behavior, slightly lower in ramp, relaxing to higher value in flattop VERY short touch on inner wall at cross-over q95 reaches 3.0 and drifts up slowly, good |
| Sep 11 2009 11:48:43:243AM | 1090911010 | Chuck Kessel | good recovery of 006 with little tweek for crossover
not much change in touch of inner wall |
| Sep 11 2009 12:02:45:790PM | 1090911011 | Chuck Kessel | added ICRF to 010, at end of Ip ramp ending at 1.1 s
got H-modes, intermitent thru flattop no RF data? |
| Sep 11 2009 12:24:53:493PM | 1090911011 | Chuck Kessel | added ICRF to 010, at end of Ip ramp ending at 1.1 s
got H-modes, intermitent thru flattop |
| Sep 11 2009 12:26:44:870PM | 1090911012 | Chuck Kessel | added ICRF
1.0 MW at 120 ms thru 500 ms, then 3 MW 500ms to 1100 ms got H-modes, intermitent thru flattop |
| Sep 11 2009 01:09:43:073PM | 1090911015 | Chuck Kessel | added ICRF
2.0 MW at 120 ms thru 500 ms, then 3 MW 500ms to 1100 ms too much radiation early, having reverse effect on li fast particle MHD? ICRF pulse is cleaner at early times |
| Sep 11 2009 01:46:55:963PM | 1090911018 | Chuck Kessel | added ICRF
1.0 MW at 120 ms, 2.0 MW at 250 ms. 3.0 MW at 500 ms ICRF choppy in flattop, still get multiple H-modes radiation early much lower, li responding great early ICRF trajectory in rampup |
| Sep 11 2009 02:26:32:567PM | 1090911019 | Chuck Kessel | added ICRF
1.0 MW at 120 ms, 2.0 MW at 250 ms. 3.0 MW at 375 ms early diverting is very good at 80 ms ICRF trajectory is pretty good will repeat this shot |
| Sep 11 2009 03:55:05:363PM | 1090911024 | Chuck Kessel | got good discharge thru rampdown
ICRF is not bad, repeat to get cleaner trace density increase led to H-modes beginning at 400 ms radiation is coming back down in rampup from previous bad discharges still super early divert |
| Physics Operator Comments | |||
| Sep 11 2009 08:34:18:167AM | Ian Hutchinson | Load from 1090903033
Ip to 1.3MA at .55s Load. | |
| Sep 11 2009 09:01:24:310AM | 1090911001 | Ian Hutchinson | Fizzle. Lots of H-alpha. Weak current. Fields look good.
This is first shot after boronization. Fill puff to 20ms from 24ms. |
| Sep 11 2009 09:15:35:090AM | 1090911002 | Ian Hutchinson | MDS hang. No power. |
| Sep 11 2009 09:42:02:243AM | 1090911003 | Ian Hutchinson | Same. No power. |
| Sep 11 2009 10:10:15:243AM | 1090911004 | Ian Hutchinson | Plasma. Disrupts at 1.6s. Rcur is moving in too fast.
OHs saturate because current limits not set right. Set negative limits to -35. Ip flattop start to .5s Ip flattop end to 1.2s ZXL rampup start to 1.2s. |
| Sep 11 2009 10:28:37:713AM | 1090911005 | Ian Hutchinson | Plasma to rampdown.
Ip ramp slight speed up early. rxl to .001 from 0. rcur to .675 at 50ms in seg 1. |
| Sep 11 2009 10:39:53:040AM | 1090911006 | Ian Hutchinson | Plasma rampdown.
Ar puff at .3s. Clearin to .012 from .01 at .3s. ICEF4 increase in ramp. |
| Sep 11 2009 10:55:26:447AM | 1090911007 | Steve Wolfe | Shot#7: Looks like this one is going to be another no power. I will sign in as physop for shot#8 and bring up PCS on cmodws08. Ian has gone to lecture. |
| Sep 11 2009 11:04:25:930AM | 1090911009 | Steve Wolfe | Shot#?: Not sure if this will be shot#7 or 8 or what. Bringing up PCS on cmodws08, getting scopes set up. Pat thinks it would be shot#9. However, it's all moot, because we're still in data system hell. |
| Sep 11 2009 11:46:19:760AM | 1090911010 | Steve Wolfe | Shot#10 (I think): Still trying to get the shot that Ian loaded before he left. The main change was a 2mm blip on clearin between .19 and .42, around crossover. plasma, some runaways, still has the crossover glitch, just touches at .36sec, made it down alive. Had an h-mode in flattop. Next: turn on rf in flattop, from 0.5 to 1.1sec raise pg4 to try to suppress runaways |
| Sep 11 2009 12:04:16:760PM | 1090911011 | Steve Wolfe | Shot#11: turn on rf in flattop, from 0.5 to 1.1sec raise pg4 from 20 to 23 msec to try to suppress runaways plasma, several h-modes, ELM free and radiating. No rf data coming through. |
| Sep 11 2009 12:14:30:947PM | 1090911012 | Steve Wolfe | Shot#12: Turn on 1MW rf at .12sec, beginning step 2. No DPCS changes this time. plasma with h-modes, made it down in. Ian is back and will take over for #13 |
| Sep 11 2009 12:27:37:027PM | 1090911012 | Ian Hutchinson | Plasma. Returning to physop.
Clearin sustained at .013 in first 0.45s. OH1V to 350V at .05s (from 250) to move plasma out. Increase ICEF4 at .25s. Load. |
| Sep 11 2009 12:39:11:620PM | 1090911013 | Ian Hutchinson | Disrupts at 0.42s after big injection at .24s and .37s
OH1V point to .047s. |
| Sep 11 2009 12:55:00:337PM | 1090911014 | Ian Hutchinson | Plasma to rampdown.
OH2V to 30V from 20V at .05s. Add OH1V point at .07 at 250V. |
| Sep 11 2009 01:07:06:243PM | 1090911015 | Ian Hutchinson | Plasma to .65s.
OH2V point at 40ms 18V Rcur gain to 5 from 4 at .038s. |
| Sep 11 2009 01:20:34:167PM | 1090911016 | Ian Hutchinson | Fizzle.
Lower fill puff to 20ms. Increase chopper quiescent current ramp up rate after 40ms to reach 1000 at 60ms. |
| Sep 11 2009 01:45:44:010PM | 1090911017 | Ian Hutchinson | Plasma to rampdown. (Some runaways?)
Clearin to .01 at .5s Fill back to 24ms. OH2V to 10 from 0 at 80ms. |
| Sep 11 2009 01:51:19:267PM | 1090911018 | Ian Hutchinson | Plasma to rampdown.
OH2V tweaks at .05. Clearin to .008 at .5s. RXL to .015 at .6s. |
| Sep 11 2009 02:24:28:190PM | 1090911019 | Ian Hutchinson | Plasma to rampdown.
Rcur gain to 3 at .04 (from 5). Start EF1V rampdown at 35ms (was 45). EF3V to 2200V at 46ms from 2300. |
| Sep 11 2009 02:58:33:130PM | 1090911020 | Ian Hutchinson | Disrupts at .45s.
rxl to .015 at .4s EF3V to 2000 at 46ms. Chopper to 300 at 40ms, faster ramp. Load |
| Sep 11 2009 03:13:40:990PM | 1090911021 | Ian Hutchinson | Fizzle.
Fill puff to 22ms. |
| Sep 11 2009 03:28:51:427PM | 1090911022 | Ian Hutchinson | Plasma to .47s
Increase density ramp to 1.25e20 at .5s. EF3V to 1800V. |
| Sep 11 2009 03:41:44:690PM | 1090911023 | Ian Hutchinson | Fizzle. |
| Sep 11 2009 03:54:18:240PM | 1090911024 | Ian Hutchinson | Plasma to rampdown.
EF1V to -100V at 41ms. Increase nl04 ramp to 1.35 Add a downward step to EF3V at .04s. |
| Sep 11 2009 04:08:56:770PM | 1090911025 | Ian Hutchinson | Disruption at 0.92s.
Rxl to .015 at 1.1s. Try to keep strike further up. nl04 to .8e20 at .2s. |
| Sep 11 2009 04:22:05:723PM | 1090911026 | Ian Hutchinson | Plasma to rampdown.
EF1V to -150V from -100V at 41ms. nl04 to 1.5e20 at .55s. |
| Sep 11 2009 04:35:05:393PM | 1090911027 | Ian Hutchinson | Fizzle.
nl04 to 1.35 at .55 and .6 at .2 |
| Sep 11 2009 04:48:31:583PM | 1090911028 | Ian Hutchinson | Disrupts at .65s
Fill puff to 18ms to try to miss the fizzle. rxl to .017 at .4s |
| Sep 11 2009 05:01:07:503PM | 1090911029 | Ian Hutchinson | Disruption at .47s
EF1 crowbar to .035s reduce nl04 demand disable argon puff EF2V to zero at 40ms. |
| Sep 11 2009 05:12:43:643PM | 1090911030 | Ian Hutchinson | Plasma to rampdown. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:53:57:763AM | Plasma | Ok | |
| 2 | 09:06:51:823AM | Test | Bad | |
| 4 | 09:53:21:277AM | Plasma | Ok | |
| 5 | 10:10:34:930AM | Plasma | Ok | |
| 6 | 10:25:45:010AM | Plasma | Ok | |
| 10 | 11:40:34:557AM | Plasma | Ok | |
| 11 | 11:55:38:180AM | Plasma | Ok | |
| 12 | 12:12:07:200PM | Plasma | Ok | |
| 13 | 12:25:10:963PM | Plasma | Ok | |
| 14 | 12:38:10:243PM | Plasma | Ok | |
| 15 | 12:52:30:713PM | Plasma | Ok | |
| 16 | 01:05:42:650PM | Plasma | Ok | |
| 17 | 01:18:36:930PM | Plasma | Ok | |
| 18 | 01:34:20:947PM | Plasma | Ok | |
| 19 | 02:12:10:033PM | Plasma | Ok | |
| 20 | 02:24:58:490PM | Plasma | Bad | OH1 Type 1 Flt |
| 21 | 02:55:21:113PM | Plasma | Ok | |
| 22 | 03:11:20:380PM | Plasma | Ok | |
| 23 | 03:26:26:753PM | Plasma | Ok | |
| 24 | 03:39:35:143PM | Plasma | Ok | |
| 25 | 03:53:09:143PM | Plasma | Ok | |
| 26 | 04:06:33:270PM | Plasma | Ok | |
| 27 | 04:19:37:990PM | Plasma | Ok | |
| 28 | 04:32:34:800PM | Plasma | Ok | |
| 29 | 04:45:39:833PM | Plasma | Ok | |
| 30 | 04:58:53:457PM | Plasma | Ok | |
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