| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Yijun Lin |
| Physics operator(s): | Earl Marmar |
| Engineering operator(s): | Andy Pfeiffer,Bill Byford,Ed Fitzgerald |
| Engineering Operator Run Comment |
| mp417 |
| Session Leader Plans |
| Entered: Mar 29 2005 04:50:48:007PM |
| Author: Yijun Lin |
| MP417 (day 2 of pre-boronization)
"Plasma performance, boronization and ICRF heating effectiveness with high-Z antenna guards and all metal surface" (Let's do as much as possible of the run plan) engineering/gas system setup the same as 1050329. <= 5 shots: ECE cutoff for Thomson calibration. 5 shots: Argon puff (calibration of bolometry and estimate of RF efficiency). Puff Argon to ohmic plasma until 100\% radiated power, then repeat a shot with 3 MW RF to 100\% radiated power. 5 shots: Repeat above with Neon puff. 5 shots: Nitrogen puff. 3 MW RF power. Start with small puff until 100\% radiated power. 3 shots: No puff. Repeat at 3 MW to see whether the N effect lasts. 6 shots: L-H threshold. Ramping up RF power from 0.5 to 3 MW. Density scan nl04 = 0.8, 1.0, and 1.2e20 m^-2. Also current scan at 0.8 MA and 1.0 MA. 4 shots: Performance vs density. density scan nl04 = 0.7, 0.8, 1.0, and 1.1e20 m^-2 at the max RF power. 2 shots: Heating hysteresis. RF notch (1 MW dip, 20 ms length) at 40 ms and 80 ms after the RF power on. Max RF power. Fiducial plasma. 5 shots: Density scan at L-mode inner wall limited plasmas. Check the scaling with density in L mode confinement. nl04 = 0.7, 0.8, 0.9, 1.0 and 1.1 e20 m^{-2} at max RF power (~4 MW). |
| Physics Operators Plans |
| Entered: Mar 30 2005 05:50:42:203PM |
| Author: Earl Marmar |
| Engineering setup for Wednesday, 30 Mar 2005 MP #417 Plasma performance, boronization and ICRF heating effectiveness with high-Z antenna guards Session leader: Lin Physics operator: Marmar Overnight ECDC in D2, bake at 60 C. Run begins at 09:00 and ends at 17:00. Power systems as on 1050329 A-coils in standard configuration (lock mode suppression): +Dtop -Dbot -Jtop +Jbot (same as 1050316) Gas Setup: fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 2 psi Ar Hybrid enabled (PG1) leave B-side upper with He3 Hybrid disabled (PG2) fill B-main (C-side) with 30 psi D2 Hybrid enabled (PG3) Enable the following: ECE gate valve, Z-bolo shutters VUV gate valve This will be a continuation from 1050329. |
| Session Leader Summaries |
| Entered: Mar 31 2005 09:45:40:667AM |
| Author: Yijun Lin |
| Summary:
Finished the following parts of the plan: 1. H-mode threshold at different current and density. 2. TS calibration using ECE cutoff. 3. 100% radiation shots usign Argon (Ohmic and RF) and Krypton (RF) Accumulated data for comparison with future post-boronization. Obtained more info for bolometry calibration. Still many questions remain to be answered, for example, the discrepancy in different bolometry measurements has not been resolved. |
| Physics Operator Summaries |
| Entered: Mar 30 2005 05:52:23:360PM |
| Author: Earl Marmar |
| Not the easiest day, but we did accomplish a fraction of the run plan. Start was delayed ~1 hour because the big door to the cell had problems; it was left closed for the day, which prevented any cell access after the first couple of shots. We got some H-mode threshold data at 0.8 MA and 1.0 MA. A few shots were devoted to Thomson/ECE-cutoff cross calibration. Data were obtained at 4.6 and 3.9 Tesla. The remainder of the run was devoted to impurity puffing to look at bolometer measurements with highly radiative plasmas. Both argon (shots 17-23) and krypton (24, 25) were used, in all cases using the B side lower plenum (PG1). We fought the intrinsic non-linearities, whereby not much happens to the plasma until the edge cools, after which the impurity screening disappears, radiation increases exponentially, and the plasma disrupts. Using modulated puffs worked moderately well, using 2 PSI in the plenum for both argon and krypton, and repetative puffs with duty factor of 40/160 ms and 60/160 ms. Adding RF power (3 MW), allowed semi-steady conditions (shots 22-25). We had problems with fizzles and duds today. As was the case yesterday, duds appeared, even though the fields and gas looked ok (e.g. shot 11). One suspicion is that LH injection into post fizzle gas may be affecting breakdown. The mechanism is unknown, but the phenomenon is reminiscent of a similar effect from ICRF vacuum conditioning. ECDC was employed between shots 11 and 12 (D2, P=2e-4 gauge) for 20 minutes. Shot 12 was fine. The LH was left off for the rest of the run. However, we also had a dud on shot 16, although in that case, the fill pressure was quite low, partly because the pre-puff plenum was down to 5.1 PSI, instead of 6. The decrease occurred primarily because of the between-shot ECDC; physops and engineering operators should keep an eye on this pressure, especially after between-shot ECDC is employed. Most shots had significant early hard x-ray. Shot 14 was the worst; it bounced during startup, and died at 0.375 s. Shot 6 had an early disruption, apparently caused by a big natural injection. There was one mystery no-TF dud (shot 18). Summary: Plasmas 17 fizzles 7 duds 2 P.S. dud 1 total cycles 27 |
| Session Leader Comments | |||
| Mar 30 2005 10:37:19:927AM | 1050330001 | Yijun Lin | shot 01 (Reload shot 1050329007)
(L-H threshold scan. 1.0 MA, 0.85e20 nl) Plasma: Bt 5.4 T, 1 MA, nl04 = 0.85e20m^-2. RF power: ramping up 1-3.5 MW, [0.6, 1.35] sec. Notch on J port at 1.2 sec result: Multiple L-H transitions. (H modes did not stay). First L-H transition at Prf = 1.1 MW. Next: raise nl to 1.e20, same current |
| Mar 30 2005 10:38:12:427AM | 1050330002 | Yijun Lin | shot 02 (L-H threshold scan. 1.0 MA, 1.e20 nl)
Plasma: Bt 5.4 T, 1 MA, nl04 = 1.e20m^-2. RF power: ramping up .4-3.5 MW, [0.6, 1.35] sec. Notch on J port at 1.2 sec result: ELMy H-mode. (stayed longer) First L-H transition at Prf = 1.85 MW. Next: raise nl to 1.2e20, same current |
| Mar 30 2005 10:51:56:173AM | 1050330003 | Yijun Lin | shot 03 (L-H threshold scan. 1.0 MA, 1.1e20 nl)
Plasma: Bt 5.4 T, 1 MA, nl04 = 1.1e20m^-2. RF power: ramping up .4-3.5 MW, [0.6, 1.35] sec. Notch on J port at 1.2 sec result: H-mode. H89 ~ 1.3 First L-H transition at Prf = 2.2 MW. Next: Lower Ip to 800 kA, same density |
| Mar 30 2005 11:07:07:127AM | 1050330004 | Yijun Lin | shot 04 (L-H threshold scan. .8 MA, 1.2e20 nl)
Plasma: Bt 5.4 T, .8 MA, nl04 = 1.2e20m^-2. RF power: ramping up .4-3.5 MW, [0.6, 1.35] sec. Notch on J port at 1.2 sec result: H-mode. First L-H transition at Prf = 2. MW. Next: Lower density to 1.0e20 nl, same current |
| Mar 30 2005 11:15:22:487AM | 1050330005 | Yijun Lin | fizzle |
| Mar 30 2005 11:33:51:980AM | 1050330006 | Yijun Lin | shot 06 disrupted at 0.47 s
|
| Mar 30 2005 11:49:08:240AM | 1050330007 | Yijun Lin | shot 07 (L-H threshold scan. .8 MA, .9e20 nl)
Plasma: Bt 5.4 T, .8 MA, nl04 = .9e20m^-2. RF power: ramping up .4-3.5 MW, [0.6, 1.35] sec. Notch on J port at 1.2 sec result: H-mode. First L-H transition at Prf = 1.5 MW. Next: Lower density to .8e20 nl, same current |
| Mar 30 2005 11:59:38:877AM | 1050330008 | Yijun Lin | shot 08 (L-H threshold scan. .8 MA, .8e20 nl)
Plasma: Bt 5.4 T, .8 MA, nl04 = .8e20m^-2. RF power: ramping up .4-3.5 MW, [0.6, 1.35] sec. Notch on J port at 1.2 sec result: H-mode. First L-H transition at Prf = 1.7 MW. Next: lower B field and raise density (Ohmic) for TS calibration (ECE cutoff) |
| Mar 30 2005 12:26:02:860PM | 1050330009 | Yijun Lin | fizzle |
| Mar 30 2005 12:31:41:687PM | 1050330010 | Yijun Lin | fizzle/dud |
| Mar 30 2005 01:01:44:790PM | 1050330011 | Yijun Lin | Dud. ECDC for 20 minutes.
(LH was firing into vacuum in fizzles because it hasn't used the fizzle detector) |
| Mar 30 2005 01:21:59:887PM | 1050330012 | Yijun Lin | shot 12 (TS calibration)
Plasma: Bt 4.6 T, 1.2 MA, nl04 up to 2e20m^-2. Some ECE cutoff at R ~0.78 m. next shot: lower B field, and lower Ip. |
| Mar 30 2005 01:46:56:227PM | 1050330013 | Yijun Lin | shot 13 (TS calibration)
Plasma: Bt 3.9 T, 0.9 MA, nl04 up to 2e20m^-2. ECE cutoff near the plasma center (good). next shot: slight change and repeat |
| Mar 30 2005 01:47:20:757PM | 1050330014 | Yijun Lin | shot 14 early disruption at 0.38 sec.
|
| Mar 30 2005 02:10:11:100PM | 1050330015 | Yijun Lin | shot 15 fizzle
next: Argon puff for bolometry calibration. |
| Mar 30 2005 02:21:59:557PM | 1050330016 | Yijun Lin | Bt 5.4 T, .8 MA, nl 1e20 m^-2.
2 psi argon B-side lower. Fizzle |
| Mar 30 2005 02:52:52:763PM | 1050330017 | Yijun Lin | shot 17 (Argon puff into ohmic plasma to get 100% radiation)
Plasma: Bt 5.4 T, .8 MA, nl 1e20 m^-2. Result: Disruption at 0.73 sec. V * I = 2.4 * 0.8 = 1.92 MW Pradmain = 2.05 MW valve was supposedly open at 0.5 sec and puff continueously. Argon was only visible at 0.6 sec. (2 psi argon B-side lower) disrupted after about 100 ms. next: puff Argon in 60 ms out of every 160 ms, starting at 0.5 sec. |
| Mar 30 2005 02:53:10:047PM | 1050330018 | Yijun Lin | No TF. |
| Mar 30 2005 03:17:30:443PM | 1050330019 | Yijun Lin | shot 19 Argon puff into ohmic plasma to get 100% radiation)
Plasma: Bt 5.4 T, .8 MA, nl 1e20 m^-2. puff Argon in 60 ms out of every 160 ms, starting at 0.5 sec. Result: Disruption at 0.93 sec. V * I = 2.16* 0.78= 1.68 MW Pradmain = 1.77 MW V was going up the same time as Prad and complicated the situation. |
| Mar 30 2005 03:19:23:973PM | 1050330020 | Yijun Lin | fizzle |
| Mar 30 2005 03:39:23:333PM | 1050330021 | Yijun Lin | shot 21: Argon puff into ohmic plasma to get 100% radiation
Plasma: Bt 5.4 T, .8 MA, nl 1e20 m^-2. puff Argon in 40 ms out of every 140 ms, starting at 0.5 sec. Result: Disruption at 1.18 sec. Next: RF on at 3 MW. Same plasma. |
| Mar 30 2005 04:08:34:387PM | 1050330022 | Yijun Lin | shot 22: Argon puff into RF heated plasma to get 100% radiation
Plasma: Bt 5.4 T, .8 MA, nl 1e20 m^-2. puff Argon in 40 ms out of every 140 ms, starting at 0.5 sec. Prf at 3 MW, [0.6, 1.35] sec. Result: disruption at 1.5 sec Prad at 1.7 MW, about half of the RF power. Next: try more argon and make disrupton during the RF. |
| Mar 30 2005 04:09:31:357PM | 1050330023 | Yijun Lin | shot 23: Argon puff into RF heated plasma to get 100% radiation
Plasma: Bt 5.4 T, .8 MA, nl 1e20 m^-2. puff Argon in 60 ms out of every 160 ms, starting at 0.5 sec. Prf at 3 MW, [0.6, 1.35] sec. Result: disruption at 1.4 sec. Prad at 1.8 MW, about half of the RF power. Next: try krypton. |
| Mar 30 2005 04:23:46:877PM | 1050330024 | Yijun Lin | shot 24: krypton puff into RF heated plasma to get 100% radiation
Plasma: Bt 5.4 T, .8 MA, nl 1e20 m^-2. puff kryton in 40 ms out of every 160 ms, starting at 0.5 sec. Prf at 3 MW, [0.6, 1.5] sec. Result: disruption at 1.54 sec. Dithering H-modes. Prad at 1.8 MW Next: more krypton. |
| Mar 31 2005 09:50:49:220AM | 1050330025 | Yijun Lin | shot 25: krypton puff into RF heated plasma to get 100% radiation
Plasma: Bt 5.4 T, .8 MA, nl 1e20 m^-2. puff kryton in 60 ms out of every 160 ms, starting at 0.5 sec. Prf at 3 MW, [0.6, 1.5] sec. Result: disruption at 1.26 sec during RF. H/D ~ 0.09 End of the Linear part at 1.2 sec. Prad 2.2 MW. Prf 3 MW. Poh ~ 0.8 MW. Does it mean RF efficiency at H/D = 0.09 was (2.2-0.8)/3.0 ~ 0.5? If using 2pi foil, Pfoil = 3.5 MW. --> rf efficiency at (3.5-0.8)/3.0 = 0.9? |
| Mar 30 2005 04:50:46:670PM | 1050330026 | Yijun Lin | shot 26 fizzle.
Next more krypton so that we can have disruption when H/D level is still low. |
| Physics Operator Comments | |||
| Mar 30 2005 09:49:38:830AM | Earl Marmar | There is a problem with the big door to the cell today. It is closed, and will not be opened during the run. As a result it is unlikely that there will be any possibility for cell access during the run, because of low oxygen levels. | |
| Mar 30 2005 10:28:10:380AM | 1050330001 | Earl Marmar | Because of problems with duds at the end of the day yesterday, we will start by trying to reproduce a standard 1 MA shot load from 1050329007, 1 MA, LSN, nl_04 target 8.5e19 prepuff 20 msec (not changed) change I_TF to -150kA (from -145.5 kA) plasma hards early disrupt in rampdown (~500 kA) |
| Mar 30 2005 10:41:21:650AM | 1050330002 | Earl Marmar | raise nl_04 target to 1.e20 increase PG3 puff in seg 1 after 20 msec plasma similar early hards marfe during density rise |
| Mar 30 2005 10:51:26:923AM | 1050330003 | Earl Marmar | delay the density rise nl_04 target to 1.2e20 gate valves open for this shot (they were closed for first 2 shots of the day) plasma marfe looks better; density rise probably could have been a bit faster early hards much lower |
| Mar 30 2005 11:05:15:677AM | 1050330004 | Earl Marmar | I_p to 0.8 MA tweak segment 2 density rise programming (a bit faster) plasma early hards are back |
| Mar 30 2005 11:18:59:673AM | 1050330005 | Earl Marmar | nl_04 target to 1.0e20 fizzle |
| Mar 30 2005 11:38:07:163AM | 1050330006 | Earl Marmar | reduce prepuff by 2 msec (to 18 msec) plasma early disruption; big increase in radiated power starting at 0.42 seconds |
| Mar 30 2005 11:51:01:723AM | 1050330007 | Earl Marmar | no pcs changes plasma |
| Mar 30 2005 12:12:29:873PM | 1050330008 | Earl Marmar | nl_04 target to 0.8e20 plasma |
| Mar 30 2005 12:15:40:233PM | 1050330009 | Earl Marmar | now go for the Thomson ECE-cutoff density calibration I_TF to -125kA I_p to 1.2 MA nl_04 to 4e20 fizzle |
| Mar 30 2005 12:31:04:827PM | 1050330010 | Earl Marmar | reduce prepuff by 2 msec to 16 msec very late, tiny breakdown; essentially a dud |
| Mar 30 2005 12:49:25:617PM | 1050330011 | Earl Marmar | add 2 msec to prepuff EF4 10 A less positive for t \le 0 dud we will stop the LH for now ECDC (D2, 2e-4 guage) for 20 minutes before the next shot |
| Mar 30 2005 01:26:49:777PM | 1050330012 | Earl Marmar | 20 minutes ECDC before this shot EF4 to -1345 A for t \le 0 plasma startup looks good; hards are gone got to nl_04 = 2e20, then disrupted late in flattop close to limit on OH1 |
| Mar 30 2005 01:50:34:110PM | 1050330013 | Earl Marmar | 4 tesla 0.9 MA plasma disrupt near end of flattop |
| Mar 30 2005 01:50:49:097PM | 1050330014 | Earl Marmar | 4 tesla 1.0 MA EF3 breaker pulled during INIT and was reset plasma bounced during startup very short and nasty; lots of hards early |
| Mar 30 2005 02:04:25:260PM | 1050330015 | Earl Marmar | add 1ms to prepuff EF4 to -1335 for t \le 0 very late breakdown fizzle |
| Mar 30 2005 02:25:09:003PM | 1050330016 | Earl Marmar | back to 5.4 Tesla, 800 kA, nl_04 = 1e20 2 psi argon B-side lower PG1 to 100 volts from 0.5 to 1.5 seconds prepuff to 20 msec EF4 current to -1345 for t \le 0 dud |
| Mar 30 2005 02:49:16:700PM | 1050330017 | Earl Marmar | B-top plenum to 6.2 psi (it had been down to 5.1) plasma disrupt around 0.7 argon starts rising about 0.6, and then rapidly increases to the disruption |
| Mar 30 2005 02:50:58:077PM | 1050330018 | Earl Marmar | modulated argon puffs, 60 ms on out of every 160 ms, starting at 0.5 s no toroidal field; supplies did not fire |
| Mar 30 2005 03:17:38:567PM | 1050330019 | Earl Marmar | no pcs changes plasma radiated power increases in steps, then goes up non-linearly toward the disruption |
| Mar 30 2005 03:20:47:037PM | 1050330020 | Earl Marmar | reduce argon puffs: 40 msec out of each 160 ms, starting at 0.5 s fizzle |
| Mar 30 2005 03:57:42:870PM | 1050330021 | Earl Marmar | reduce prepuff by 2 ms to 18 ms turn off ninja puff plasma disrupts later |
| Mar 30 2005 03:58:26:120PM | 1050330022 | Earl Marmar | turn on RF during argon puff (3 MW) survives until after RF |
| Mar 30 2005 04:03:44:837PM | 1050330023 | Earl Marmar | increase argon by 50% (60 ms out of every 160 ms) plasma disrupts after RF turns off |
| Mar 30 2005 04:26:12:533PM | 1050330024 | Earl Marmar | switch to krypton, 2 psi, B side lower puff 40 ms out of each 160 ms, starting at 0.5 s plasma disrupts after the RF turns off Zeff is rising to ~2 during the RF |
| Mar 30 2005 04:47:13:780PM | 1050330025 | Earl Marmar | increase krypton about 50% (60 ms on out of every 160 ms) plasma disrupts during RF pulse |
| Mar 30 2005 04:47:26:153PM | 1050330026 | Earl Marmar | no pcs changes fizzle |
| Mar 30 2005 05:00:54:080PM | 1050330027 | Earl Marmar | reduce prefill puff by 2 msec increase krypton (75 ms out of every 160 ms) fizzle, late breakdown |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 10:09:49:013AM | Plasma | Ok | |
| 2 | 10:30:14:147AM | Plasma | Ok | |
| 3 | 10:43:17:497AM | Plasma | Ok | |
| 4 | 10:56:14:813AM | Plasma | Ok | |
| 5 | 11:12:48:627AM | Plasma | Ok | |
| 6 | 11:27:29:967AM | Plasma | Ok | |
| 7 | 11:41:20:290AM | Plasma | Ok | |
| 8 | 11:53:44:317AM | Plasma | Ok | |
| 9 | 12:12:52:780PM | Plasma | Ok | |
| 10 | 12:25:21:483PM | Plasma | Ok | |
| 11 | 12:38:15:393PM | Plasma | Ok | |
| 12 | 01:12:55:040PM | Plasma | Ok | |
| 13 | 01:26:43:340PM | Plasma | Ok | |
| 14 | 01:41:04:057PM | Plasma | Ok | |
| 15 | 01:57:21:730PM | Plasma | Ok | |
| 16 | 02:17:37:723PM | Plasma | Ok | |
| 17 | 02:30:18:477PM | Plasma | Ok | |
| 18 | 02:49:06:530PM | Plasma | Bad | TF did not fire. PLC trigger suspected. |
| 19 | 03:01:36:703PM | Plasma | Ok | |
| 20 | 03:17:02:177PM | Plasma | Ok | |
| 21 | 03:29:47:537PM | Plasma | Ok | |
| 22 | 03:42:32:320PM | Plasma | Ok | |
| 23 | 03:57:40:713PM | Plasma | Ok | |
| 24 | 04:15:36:977PM | Plasma | Ok | |
| 25 | 04:28:25:960PM | Plasma | Ok | |
| 26 | 04:44:28:170PM | Plasma | Ok | |
| 27 | 04:57:37:673PM | Plasma | Ok | |