| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Amanda Hubbard |
| Physics operator(s): | Earl Marmar |
| Engineering operator(s): | Bill Parkin,Bill Byford,Gary Dekow |
| Engineering Operator Run Comment |
| Purpose: MP 340 Investigation of fast edge response at the L-H transitio |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:33:350PM |
| Author: Amanda Hubbard |
| Run Summary for 1030630 MP 340: Investigation of fast edge response at the L-H transition Session Leader: Amanda Hubbard Physics Operator: Earl Marmar RF Ops: Steve W, Yijun, Charlie Physics run plan for 1030620 The aim of this experiment is to characterize the edge Te and ne response at the L-H transition, as a function of input power, on a fast (sub-ms) time scale. Higher field (6.1 T) plasmas will be used so as to place FRCECE channels in the pedestal and to minimize sawtooth amplitude. The run will closely follow the posted MP. We will start with shot 1021105027 (6.1 T, 800 kA, nel 8e19 m-2). Flat top shortened to 1.3 secs. RF pulse will be delayed to 0.8 secs to assure constant Bt and plasma. First shot will have ramped waveform, 0.5 MW to 2.5 MW, 0.8-1.3 secs. Subsequent shots will have flat waveform with fast (5ms) turnons; start with low power and increase shot to shot. A higher power may be added late in the discharge to help condition antennas (at RF operators' discretion); otherwise, we may further shorten the discharge. All going well, for the second half of the run we will raise nel to 1.2e20 m-2, and repeat the sequence. Critical diagnostics will be FRCECE, visible bremsstrahlung (with max sampling rate), edge TS and bolometers. CXRS and BES would be useful; beam should be set for time of LH transition (expected ~ 0.85 secs, may vary with power). Reflectometry and PCI also useful; may be interesting to monitor QC mode as a funtion of power. Results: Run got off to a difficult start due to poor cooling in the cell. This apparently caused PCI failures to FRCECE, and problems for several other diagnostics. For some early shots, FRCECE unfortunately had to be turned off to cool down. We succeeded in getting transitions at the lower target density, ~8e19 m-2, over a wide range of powers. A few shots were clearly at the L-H threshold, with long dithering periods and a very late transition (see 005 and 007 and 020 (with FRCECE). Got good L-mode ETS data which will be analysed for threshold conditions. A range of other powers were used, up to 5.1 MW at the LH transition. From shot 13 the RF turnon rate was increased, giving ~10 ms rise time vs ~20 ms earlier. The L-H transition moved earlier as P was raised. GPC Ch 8 saw a jump on all discharges, as did FRCECE Chs 12-15 when available. Useful shots at this density are: SHOT Power(at LH) FRCECE data Comment 3 1.7 MW Y slightly higher target ne 4 1.44 N " " " 5 1.25 N Dithering, good threshold shot 6 2.0 Y 7 1.3 N Threshold, but faster transition 9 2.9 N 10 3.6 MW N Better EDA 12 3.9 N 13 4.3 N Faster rise time 14 4.5 Y 16 1.67 Y One dither, before L-H 17 2.7 Y Injection before L-H confuses transition 18 2.67 Y CLean transition. 20 1.3 MW Y Threshold shot, long dithering period 21 5.1 MW Y Clean transiton For the remainder of the run, we attempted to repeat the scan at higher densities. However, a delay due to a TF crowbar meant we only got a few more shots. Two were L-mode, while the RF retuned. We got one L-H transition, at a slightly higher density than the above series. The last shot, at 1.3e20 m-3, might have been dithering or had a brief transition. In summary, we got a good scan for analysis at one density. It was not immediately clear that the moderate and high density cases had very different dynamics. The threshold cases were different, with many dithering cycles. They should provide good data for comparison with thresshold models. We will likely request further run time for the density variation part of the proposal. |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:37:18:440PM |
| Author: Earl Marmar |
| Physics Operator Summary for 1030620. Purpose: Boronization recovery MP 318 High performance at 5 T Session leader: Marmar Physics operator: Rowan Engineer operators: Dekow, Byford, Parkin Engineering setup-------------------------------------------------------------- ECDC after boronization in D2 at 2e-4 Torr, stopping by 06:00. Bake at 60 C after boronization, if possible. Run begins at 08:00 and ends at 15:00. NOTE CHANGE IN STARTING AND ENDING TIMES Power systems the same as on 1030530027. A-coils should be hooked up as on 1030507027 (+Dtop -Dbot -Jtop +Jbot), and the power supply should be enabled. Gas setup: fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar Hybrid enabled (PG1) fill B-side upper with 10 psi D2 Hybrid DISABLED (PG2) (for ECDC) fill C-side with 30 psi D2 Hybrid enabled (PG3) Enable the following gate valves, assuming no vacuum problems: ECE, DNB RF Setup: All 4 transmitters in Run On by 07:00. ------------------------------------------------------------------------------- Results------------------------------------------------------------------------ Boronization was completed. Approximately 1.5 hours of ECDC was completed before the run. It was expected that lack of ECDC this would lead to a repeat of the last boronization recovery -- fizzles and duds. Instead, there were no fizzles or duds. Boronization recovery went well. After only a few shots, MP318 was started. It included BT scans, IP scans, and nl_04 scans. See the session leader summary for details. Score card Plasmas 32 (9 with disruptions before ramp down) Fizzles 0 Duds 0 Total 32 ------------------------------------------------------------------------------- Details------------------------------------------------------------------------- Boronization completed. Only approximately 1.5 hours of ECDC before the cut off time of 6am. Short duration of ECDC after the last boronization was credited with the problems getting plasma on the first day after boronization. There will be a need for some ECDC before the run begins if RF does significant conditioning. Loaded shot 1030530027 as requested by the SL. Loaded segment 1 from shot 1030612006 which is a more recent startup. Did not use a shot from 1030613 due to comments on physop report for that run. 001. Plasma. Not bad for the first shot after boronization. RF at 0.7 s 1 to 2 MW. H-modes at 0.83 s and 0.93 s Next shot. No PCS changes. 002. Plasma. H-modes between 0.6 and 0.9 s Next shot. No PCS changes. 003. Plasma. Couple of H-modes. First w/duration of 0.3s. Second duration is 0.2s Next shot. No PCS changes. 004. Plasma. H-mpde starting at 0.6s. Noise on ratiomatic. Pressure is creeping up. Next shot. No PCS changes. 005. Plasma. Next shot. No PCS changes. 006. Plasma. Disruption at 1.4 s. Next shot. No PCS changes. 007. Plasma. Next shot. No PCS changes. 008. Plasma Next shot. No PCS changes. 009. Plasma. Next shot. No pPCS changes. 010. Plasma. Next shot. Lower nl_04 from 5e19 to 4e19 011. Plasma. Target nl_04 = 4.6e+19 Next shot. Increase nl_04 from 4e19 to 5e19 BT increase. Current increased from 148kA to 158kA 012. Plasma. BT = 5.7T Target nl_04=5.3e+19 Next shot. No PCS changes 013. Plasma. Next shot. No PCS changes 014. Plasma Next shot. No PCS changes. EO change. Bill Byford 015. Plasma. Next shot. Changed Ip from 600 kA to 800 kA. 016. Plasma. IP=790kA Next shot. BT reduction. Current reduced from 158kA to 150kA 017. Plasma. Disruption at 0.74s BT = 5.4T Next shot. Increase nl_04 from 5e19 to 7e19 018. Plasma. Disruption at 1.5s. Target nl_04=6.5e+19 Next shot. No changes 019. Plasma. Full length. Next shot. No changes. 020. Plasma. Next shot. No PCS changes. 021. Plasma. Disruption at 0.81s Next shot. No PCS changes. 022. Plasma. Disruption at 0.75 s Next shot. ZXL moved up by 5mm 023. Plasma. Next shot. Increased nl_04 from 7.0e+19 to 7.5e19 024. Plasma. Next shot. Slight change in Ip at the changeover from segment 1 to segment 2 025. Plasma. Next shot. Slight change in IP the changeover from segment 1 to segment 2 Previous change did not accomplish as much as I wanted. 026. Plasma Disruption at 1.2s Next shot. Increase IP to 1 MA 027. Plasma. Next shot. Decrease the nl_04 from 7.5e+19 to 5.0e+19 EO: Bill Parkin 028. Plasma. Disruption at 1.3s Next shot. Increase nl_04 from 5.0e+19 to 9.5e+19 zcur moved up by 5mm 029. Died at approximately 0.14s. Next shot. No changes. 030. Plasma. Full length. Next shot. Repeat. 031. Plasma. Disruption at 1.4s Next shot. C-coils turned off by engineers A-coil demand set to zero 032. Plasma. Full length. Last shot. We are stopping at 3pm today. |
| Session Leader Comments | |||
| Jun 20 2003 08:57:43:323AM | Amanda Hubbard | Physics run plan for 1030620 MP 340: Investigation of fast edge response at the L-H transition The aim of this experiment is to characterize the edge Te and ne response at the L-H transition, as a function of input power, on a fast (sub-ms) time scale. Higher field (6.1 T) plasmas will be used so as to place FRCECE channels in the pedestal and to minimize sawtooth amplitude. The run will closely follow the posted MP. We will start with shot 1021105027 (6.1 T, 800 kA, nel 8e19 m-2). Flat top shortened to 1.3 secs. RF pulse will be delayed to 0.8 secs to assure constant Bt and plasma. First shot will have ramped waveform, 0.5 MW to 2.5 MW, 0.8-1.3 secs. Subsequent shots will have flat waveform with fast (5ms) turnons; start with low power and increase shot to shot. A higher power may be added late in the discharge to help condition antennas (at RF operators' discretion); otherwise, we may further shorten the discharge. All going well, for the second half of the run we will raise nel to 1.2e20 m-2, and repeat the sequence. Critical diagnostics will be FRCECE, visible bremsstrahlung (with max sampling rate), edge TS and bolometers. CXRS and BES would be useful; beam should be set for time of LH transition (expected ~ 0.85 secs, may vary with power). Reflectometry and PCI also useful; may be interesting to monitor QC mode as a funtion of power. | |
| Jun 20 2003 09:17:30:783AM | 1030620001 | Amanda Hubbard | Short (~300 ms) discharge. Good news is that FRCECE is working well. GPC too, but GPC2 has several channels saturated. |
| Jun 20 2003 09:40:17:530AM | 1030620002 | Amanda Hubbard | Good shot. RF ramping to find threshold. L-H at 1.53 MW, 1.00 desc. Some dithering before transition. Small RF trip after L-H, may affect analysis. |
| Jun 20 2003 09:58:57:473AM | 1030620003 | Amanda Hubbard | Constant RF, 1.7 MW. L-H at 0.88 secs. Next shot, lower power. |
| Jun 20 2003 10:04:28:527AM | 1030620004 | Amanda Hubbard | Constant RF, 1.5 MW. L-H at 0.90 secs. On VB feedback; may have been slighly lower density. (just as well, TCI failed) Repeat, lower RF to delay transition. |
| Jun 20 2003 10:35:18:060AM | 1030620005 | Amanda Hubbard | Nice shot, long dithering period and late L-H. Unfortunately, FRCECE PCI not working. Next shot, raise RF power. |
| Jun 20 2003 10:40:53:723AM | 1030620006 | Amanda Hubbard | RF 2 MW. L-H at 0.84 secs. FRCECE slow PCI data are OK. Go back and repeat shot 5, while it's working. |
| Jun 20 2003 11:14:36:043AM | 1030620007 | Amanda Hubbard | 1.3 MW. Earlier L-H this time (compared to shot 5). And FRCECE didn't work after all. Cell getting warm! Next shot, go for 2.5 MW. |
| Jun 20 2003 12:25:02:220PM | 1030620009 | Amanda Hubbard | 2.9 MW. Early L-H, at 0.827 secs. Clear jump on GPC TE8, lasts ~ 0.4 ms. FRCECE turned off. |
| Jun 20 2003 04:07:59:053PM | 1030620009 | Amanda Hubbard | 2.9 MW, L-H at 0.827 secs. |
| Jun 20 2003 12:22:50:263PM | 1030620010 | Amanda Hubbard | 3.6 MW. Early L-H, at 0.825 secs. Clear jump on GPC TE8, lasts ~ 0.6 ms. FRCECE turned off. Next shot, go for 4.0 MW. |
| Jun 20 2003 12:24:27:907PM | 1030620012 | Amanda Hubbard | 3.9 MW. Early L-H, at 0.821 secs. Clear jump on GPC TE8, lasts ~ 0.8 ms. FRCECE turned off. Next shot, go for 4.5 MW. |
| Jun 20 2003 12:50:57:403PM | 1030620013 | Amanda Hubbard | 4.3 MW, some trips. Early L-H, at 0.818 secs. Jump on GPC TE8, lasts ~ 0.8 ms. Next shot, try for FRCECE, also faster RF turnon. |
| Jun 20 2003 01:13:08:180PM | 1030620014 | Amanda Hubbard | 4.0 MW, some trips. Faster turnon, earlier L-H, at 0.816 secs. GOT FRCECE, jumps seen on Chs 12-15. ~0.4 msecs. Also on GPC Te8, seems slower (0.8 ms) Next shot, go back to 1.5 MW. |
| Jun 20 2003 04:09:36:340PM | 1030620016 | Amanda Hubbard | 1.7 MW, clean. Got FRCECE. One 'dither', followed by L-H at 0.843. Jump seems less clear. - |
| Jun 20 2003 01:41:43:103PM | 1030620017 | Amanda Hubbard | 2.5 MW. Transition confused by an injection at .825 secs (possibly an early LH as well). Main LH at 0.85 secs. Repeat. |
| Jun 20 2003 04:10:40:420PM | 1030620018 | Amanda Hubbard | 2.7 MW, nice L-H transition at 0.826 secs. Got FRCECE. |
| Jun 20 2003 02:27:23:340PM | 1030620020 | Amanda Hubbard | 1.37 MW, nice low power threshold shot. Dithers for long time, final L-H transition at 0.933 s. Got FRCECE. Next shot, go for max RF. |
| Jun 20 2003 02:41:24:437PM | 1030620021 | Amanda Hubbard | Transition at 5.1 MW, 0.814 s. Clear jumps. FRCECE ch 13 ~1.24 ms, 50 eV. This will be the high P point of the power scan at this target density. Next shot, raise the target and start with an RF ramp to find the new threshold. |
| Jun 20 2003 03:33:45:050PM | 1030620022 | Amanda Hubbard | Higher target ne, nel=1.2e20 m-2. Only got ramp to 0.75 MW; L-mode. |
| Jun 20 2003 03:34:28:643PM | 1030620023 | Amanda Hubbard | nel=1.2e20 m-2. Ramp to 1.3 MW; L-mode. |
| Jun 20 2003 03:38:46:650PM | 1030620024 | Amanda Hubbard | Ugh. TF crowbar in startup. |
| Jun 20 2003 04:29:56:637PM | 1030620025 | Amanda Hubbard | 50 kA TF test. |
| Jun 20 2003 04:54:08:330PM | 1030620026 | Amanda Hubbard | Got an L-H transition. But, no FRCECE. Also, density at LH transition ended up only marginally higher than previous discharges (nel_04 1.05e20 m-2 at the transition). Jump in Te8 ~0.8 ms, 23 eV. |
| Jun 20 2003 05:20:19:700PM | 1030620028 | Amanda Hubbard | Back to higher target nel. Got L-mode, possibly a dithering transition ~ 0.84 secs. |
| Physics Operator Comments | |||
| Jun 20 2003 09:31:12:287AM | 1030620001 | Earl Marmar | load from 1030617002 import segment 2 from 1021105027 into SEGMENT 3 start rampdown at 1.3 seconds instead of 1.5 (various mods) plasma disrupt at 0.278 s looks like efc is misbehaving; plc was set for 300 V instead of 800 V on the chopper |
| Jun 20 2003 01:12:42:133PM | 1030620002 | Earl Marmar | plasma good shot efc ok on this shot |
| Jun 20 2003 01:13:19:273PM | 1030620003 | Earl Marmar | no pcs changes plasma |
| Jun 20 2003 10:02:09:773AM | 1030620004 | Earl Marmar | switch to z-meter density feedback; 0.17 volts plasma looks like slightly lower target density some hards early |
| Jun 20 2003 10:19:17:417AM | 1030620005 | Earl Marmar | add 1 msec to prefill puff plasma; still early hards |
| Jun 20 2003 11:19:30:690AM | 1030620006 | Earl Marmar | add another 1 msec to prepuff; now at 27 ms plasma |
| Jun 20 2003 11:19:40:910AM | 1030620007 | Earl Marmar | no pcs changes plasma |
| Jun 20 2003 11:35:50:973AM | 1030620008 | Earl Marmar | data system hang no power shot |
| Jun 20 2003 11:36:16:617AM | 1030620009 | Earl Marmar | no pcs changes plasma still early hards |
| Jun 20 2003 12:00:46:067PM | 1030620010 | Earl Marmar | no pcs changes plasma |
| Jun 20 2003 12:07:30:917PM | 1030620011 | Earl Marmar | no pcs changes fizzle |
| Jun 20 2003 12:17:28:087PM | 1030620012 | Earl Marmar | reduce prepuff by 1 msec plasma |
| Jun 20 2003 12:48:04:213PM | 1030620013 | Earl Marmar | no pcs changes plasma |
| Jun 20 2003 12:56:11:647PM | 1030620014 | Earl Marmar | no pcs changes plasma early hards are back |
| Jun 20 2003 01:06:33:500PM | 1030620015 | Earl Marmar | no pcs changes fizzle |
| Jun 20 2003 01:41:16:260PM | 1030620016 | Earl Marmar | reduce prepuff another 1 msec (now 25 msec) plasma |
| Jun 20 2003 01:41:49:307PM | 1030620017 | Earl Marmar | no pcs changes plasma |
| Jun 20 2003 01:53:39:103PM | 1030620018 | Earl Marmar | start tf rampdown at 1.1 seconds plasma |
| Jun 20 2003 02:00:34:487PM | 1030620019 | Earl Marmar | no pcs changes fizzle |
| Jun 20 2003 02:19:34:950PM | 1030620020 | Earl Marmar | add 1 msec to prepuff plasma hard x-rays significantly more intense |
| Jun 20 2003 02:41:21:313PM | 1030620021 | Earl Marmar | no pcs changes plasma hards are lower |
| Jun 20 2003 02:47:21:417PM | 1030620022 | Earl Marmar | increase nl_zmeter demand to .42 V extend TF flattop to 1.3 seconds plasma |
| Jun 20 2003 03:29:10:027PM | 1030620023 | Earl Marmar | reduce nl_ameter demand after 0.8 seconds plasma |
| Jun 20 2003 03:28:01:383PM | 1030620024 | Earl Marmar | reduce nl_zmeter target to 0.35 fizzle TF crowbar right around t=0 |
| Jun 20 2003 04:34:20:703PM | 1030620025 | Earl Marmar | 50 kA TF test under plc control |
| Jun 20 2003 04:51:06:060PM | 1030620026 | Earl Marmar | no pcs changes plasma |
| Jun 20 2003 05:04:58:440PM | 1030620027 | Earl Marmar | nl_zmeter demand to .42 V no power; data system problems during init |
| Jun 20 2003 05:19:11:477PM | 1030620028 | Earl Marmar | plasma |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:03:12:080AM | Plasma | Ok | |
| 2 | 09:22:47:057AM | Plasma | Ok | |
| 3 | 09:36:43:760AM | Plasma | Ok | |
| 4 | 09:51:32:653AM | Plasma | Ok | |
| 5 | 10:11:03:207AM | Plasma | Ok | |
| 6 | 10:32:06:620AM | Plasma | Ok | |
| 7 | 10:46:45:810AM | Plasma | Ok | |
| 8 | 11:10:47:853AM | Plasma | Bad | No Power Shot IGOR Problem |
| 9 | 11:27:34:870AM | Plasma | Ok | |
| 10 | 11:41:02:043AM | Plasma | Ok | |
| 11 | 11:57:31:470AM | Plasma | Ok | |
| 12 | 12:12:18:517PM | Plasma | Ok | |
| 13 | 12:31:21:507PM | Plasma | Ok | |
| 14 | 12:48:12:700PM | Plasma | Ok | |
| 15 | 01:01:02:933PM | Plasma | Ok | |
| 16 | 01:13:51:090PM | Plasma | Ok | |
| 17 | 01:30:05:153PM | Plasma | Ok | |
| 18 | 01:43:27:590PM | Plasma | Ok | |
| 19 | 01:56:28:103PM | Plasma | Ok | |
| 20 | 02:09:42:873PM | Plasma | Ok | |
| 21 | 02:27:33:510PM | Plasma | Ok | |
| 22 | 02:41:54:533PM | Plasma | Ok | |
| 23 | 03:05:22:303PM | Plasma | Ok | |
| 24 | 03:19:28:560PM | Plasma | Bad | TF Type1 fault |
| 25 | 04:23:29:797PM | Test | Ok | TF test pulse 50kA, PLC |
| 26 | 04:32:48:373PM | Plasma | Ok | |
| 27 | 04:57:56:820PM | Plasma | Bad | No power shot |
| 28 | 05:12:46:373PM | Plasma | Ok | |