| Miniproposals | ||||||||||
|
| Operators | |
| Session leader(s): | Yuichi Takase |
| Physics operator(s): | Steve Horne,Robert Granetz |
| Engineering operator(s): | Vinny Bertolino,Joe Daigle |
| Engineering Operator Run Comment |
| high field (6.4T)Horne |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:13:693PM |
| Author: To Be Determined |
| MP110A H-He3 Mode Conversion Heating (6.4T) SL: Takase PO: Horne/Granetz EO: Bertolino/Daigle This was our first attempt at running C-Mod at 6.5T. The plasma ran extremely reliably, with no major problems. We have observed DIRECT electron heating, and were able to shift the power deposition zone radially by changing the He3 concentration. Preliminary indication is that higher He3 concentration gives more central power deposition. RF had cross-coupling problems between the two antennas (due to poor single-pass absorption) and most of the data were taken with only one antenna. ECDC in H2 shot 01 test 02 pl 5.4T, 0.6MA, X-rays 03 pl 5.4T, nel_04=0.8e20 04 pl 5.9T, nel_04=0.8, RF on with modulation 05 pl 6.6T, nel_04=0.7->1.0->0.6 (He3 puff 90V 0.5-0.55sec) E port tripped better e heating than shot 004 He3 pumps out according to McPherson Try to keep He3 puff at a lower level for next shot delay due to alternator problem 06 pl 6.5T, nel_04=0.8->1.9->0.8 (nel prog step-up too early) He3 puff 90V 0.5-0.55sec, 35V 0.55-0.9sec no E-port 07 pl 6.5T, 0.8MA, nel_04=0.7->1.1->0.9 (nel prog step-up still too early) E-port tripped 08 pl nel_04=0.7->1.0->0.9 E-port tripped 09 pl nel_04=0.7->1.0 (density drop fixed) Heating moves off-axis with time D & E tripping 10 pl nel_04=0.7->1.0 He3 puff 90V 0.5-0.55sec, 50V 0.55-0.9sec Heating stays on-axis D & E tripping 11 pl same D & E tripping 12 pl fixed outer gap excursion, R_gap=1.5cm 13 pl larger outer gap, R_gap=2.3cm 14 pl still having trouble running both antennas together (cross-talk) E-port only this time 15 pl D-port only (giving up on two antenna operation for today) R_gap=1.6->1.2cm 16 pl R_gap=1.3cm, P_D=0.5-1.5MW 17 pl same, McPherson not working for 15, 16, 17 start He3 scan 18 pl He3 puff 90V 0.5-0.55sec, 50V 0.55-0.9sec, HeII(304)=5, Te0(max)=2.5keV 19 pl no He3 puff, HeII(304)=3, Te0(max)=2.0keV 20 pl no He3 again, HeII(304)=2, Te0(max)=2.0keV 21 pl He3 90V 0.5-0.53sec, 40V 0.53-0.9sec, HeII(304)=3-4, Te0(max)=2.2keV 22 pl He3 90V 0.5-0.57sec, 60V 0.57-0.9sec, HeII(304)=4-11, Te0(max)=2.2keV short RF 23 pl lowered initial density, He3 90V 0.5-0.57sec, 55V 0.57-0.9sec, HeII(304)=5-8, no RF OH2 adjustment 24 pl He3 90V 0.5-0.57sec, 40V 0.57-0.9sec, 25 pl same, some RF from D & E, HeII(304)=4, Te0(max)=3keV 26 pl same, D-port OK, HeII(304)=4, Te0(max)=3.0keV |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:36:54:177PM |
| Author: To Be Determined |
| Run plan // run report -- 950510 MP 110A H - He3 Mode conversion Heating, TF = 6.4 T. Engineering notes: ECDC in Hydrogen before run. (See OPS bulletin from Yuichi.) Hydrogen on A side (pulse_gas3), fill at 2.0e-5, plenum pressure 20 lb. (Purge before filling). He 3 on B side upper (pulse_gas2) Settings as for last shot on 950509, EXCEPT: TF start time = -.96 sec TF current limit set to give 181 KA on TF Rogowski. note -- 181KA is what we want, not what you "set" on the PLC. Use the test shots to determine the necessary calibration. TF Flat top should be reached at about 400 msec. Set TF Fizzle Delay accordingly. Physics Issues: Breakdown fields: Start TF ramp at -0.96 sec. The objective is to be ramping through 5.3 T at commutation. Breakdown tweaks will probably include tf start time. TF flat-top at 181 KA will be reached at about 0.4 sec. This is very near the IP flat-top at 800 ka. This will put the disruption (and fizzle detector) on the TF high tap, with roughly 400 msec to go to TF flattop. This is to be compared with the 500 msec delay from fizzle to TF invert, and an engineering decision needs to be made on whether this is sufficient margin. Gwinn recommends modifying the delay to 700 msec. Gas -- check previous runs to see H/D startup differences. According to Wolfe (950425) the EF2 supplies tend to rail in H due to plasma being cold. He ran fill of 2.0e-5. Put He3 in B Side Upper, verify fizzle detector disables it. (Make sure we don't puff during a fizzle. He3 is expensive.) How will concentration be monitered? I propose to begin at IP = 600 KA until breakdown, RF, and rampdown are debugged (the latter only to some extent, to avoid the disruption/fizzle cycle). Plan to load segment 2 from 950505028, H-Mode run, 600 KA shot. RUN REPORT -- The run went astonishingly well; we ran with TF = 6.5 Tesla from shot 5 on. Breakdown was reproducible (no fizzles). The only change from yesterday's breakdown sequence was to delay the TF start an additional 40 msec, to -960 msec. This was probably unnecessary. Compared to yesterday, BR ran perhaps 0.5 to 1.0 mT more positive. There seemed to be a correlation with BR and slight breakdown delays; one could argue that the BR offset should be reduced by 0.5 mT but the existing setting did work. Rampdowns were quite consistent also. I wasn't keeping close track, but I think the worst disruption was on rampdown, at IP = 360 KA. The TF was disconnected from the fizzle detector for the test shots. We'd planned to reconnect it after the first fizzle. As far as I know it's still disconnected. The major obective of the run -- scanning the He3 concentration -- was achieved; evidence of heating was observed. The He3 knob was the gas valve voltage; this seemed to work fairly well. An alternative approach of adding the He3 valve to the NL controller was considered but not tried. I suspect this would be a better way of doing the scan (by varying the He3 weight in the controller) since (presumably) excursions like the one on shot 22 wouldn't happen. I recommend that this be tried tomorrow. Bob Granetz took over as physop at 4:00. ======== Log ========== COLDSTART AT 7:45 There will be several test shots; test alternator mods, then a couple of shots to gingerly bring up the TF current. These will all be plasma attempts. The fizzle detector will be disabled for the TF only. 1 test, no plasma 2 fill 2.0e-5. X-rays. Plasma current has a bite taken out. Scatterplot against first 5 shots yesterday is more or less an overlay. raise fill to 2.5e-5 , raise early gas puff a little. Alternator overvoltage trip. 3 Better. No xrays, current looks better. raise TF. Set 170. Expect about 165 KA ==> about 6 T. 4. Plasma, breakdown looks nominal. Rampdown ok. Breakdown during transition from high to low TF taps. TF at t=0 is -153 ka. Should move tf start a few msec later, but wait till after next. Set 190 on tf, expect about 180. Should be near nominal 6.4 T. 5. Plasma, looks ok. TF current flattop at 183.3. Back off setting to 188. Flattop reached at 500 msec instead of 400. This is because transition to low tap is still at about t=0. We apparently can't hold high taps beyond this point due to alternator limitations. Therefore we need either to accept TF flattop at .5 sec, or start TF earlier and fight the startup battle. For now accept the flattop at .5 sec. btor says -6.58 Drop ef2xef4 gain from 2.0 to 1.5 (it's oscillating) Adjust NL programming (step up to 1.e20) and He3 puff (hold it on at 35 v tp .9 sec). 6 Good shot. BTOR says 6.5 T. Oscillation on ef2/ef4 gone. Adjust nl programming a little. Raise IP to 800 KA. 5 more msec argon. 7 Plasma. power supplies look OK (3000 A on ef2) Tweaks to nl4 programming 5 more msec Ar. 8. Plasma. The drop in density at .8 was due to preprogrammed v turning off there. Fixed that. 9. Plasma. Density trace flat(ter) now. Raise helium voltage from 35 to 50. 10 plasma, disrupt at 360 ka. (slightly earlier than it has been.) Tweak rampdown slightly. Adjust RF power also. 11 Plasma; disruption moved later. Tweak further. Adjust RCUR to try to hold right gap constant. 12 that worked. Now adjust rt gap to 2 cm. (move rcur 3 mm in.) 13 Plasma; ef2 u on current rail. Adjust clearin to (hopefully) prevent that. 14 Plasma, ef2 better. RF requests sweep of rt gap from 1.5 to 1 cm; adjust rcur to do that. 15 Plasma; ef2 looks much better. Adjust rcur to hold outer gap at about 1.1-1.2 cm. Small, delicate tweak of nl programming. 16 Plasma. Lump of crud fell in at 800 msec, but plasma survives. No changes except complain that Macpherson He signel gone. 17 Plasma 18 Plasma. Macphereson fixed. Next shot, He 3 off. NL programming adjusted to give same nel in H only. 19 Plasma. NL looks ok. There is still significant He3 from walls; Mcpher signal down to 3 from 5 (arbs.) Disable He3 again. 20 Plasma. mcpher down to 2. Re-enable He3 valve; modify pulse_gas2 to give an intermediate density -- less than shot 18. 21 Plasma. Try to double He3 compared to shot 18. 22 Plasma, too much nl. Adjust NL and He3 programming. It looks like when the br at breakdown drifts up the breakdown is delayed. (scatterplot, compared to yesterday.) Bob Granetz takes over as physop. 23 Plasma, better density than last shot, but still a little too much He3. Lower He3 for the next shot. RF arc'ed out early. Joe Daigle adjusted the margin angle voltage on the OH2 supplies from 6.5 to 7.5 (to make them rectify harder and invert harder) after shot 23 24 Plasma. Good NL control. Again the RF didn't perform well. Next shot: repeat with no changes, and hope RF works better. 25 Plasma. NL okay. RF worked this time. No changes for next shot. 26 Plasma. RF worked. End of run. |
| Session Leader Comments | |||
| May 10 1995 08:42:38:760AM | 950510001 | Yuichi Takase | MP110A H-He3 Mode Conversion Heating (6.4T)
shot 001: test |
| May 10 1995 08:43:28:830AM | 950510002 | Yuichi Takase | shot 002: 5.3T, plasma (X-rays)
|
| May 10 1995 09:11:37:420AM | 950510004 | Yuichi Takase | shot 004: 5.8T, nel_04=0.8e20 (RF on with modulation, no He3)
|
| May 10 1995 10:32:19:560AM | 950510006 | Yuichi Takase | shot 006: 6.5T, nel_04=0.8->1.9->0.8 (nel prog step-up too early)
no E port |
| May 10 1995 10:53:43:870AM | 950510007 | Yuichi Takase | shot 007: 6.5T, nel_04=0.7->1.1->0.9 (nel prog step-up still too early)
E-port tripped |
| May 10 1995 11:43:36:080AM | 950510007 | Yuichi Takase | shot 007: 6.5T, 0.8MA
nel_04=0.7->1.1->0.9 (nel prog step-up still too early) E-port tripped |
| May 10 1995 11:44:06:010AM | 950510008 | Yuichi Takase | shot 008: 6.5T, 0.8MA
nel_04=0.7->1.0->0.9 E-port tripped |
| May 10 1995 11:45:08:560AM | 950510009 | Yuichi Takase | shot 009: 6.5T, 0.8MA
nel_04=0.7->1.0 (density drop fixed) D & E tripping Heating moves off-axis with time |
| May 10 1995 05:53:26:230PM | 950510010 | Yuichi Takase | shot 010: 6.5T, 0.8MA
nel_04=0.7->1.0 He3 puff 90V 0.5-0.55sec, 50V 0.55-0.9sec Heating stays on-axis D & E tripping |
| May 10 1995 05:54:00:330PM | 950510011 | Yuichi Takase | shot 011: 6.5T, 0.8MA
nel_04=0.7->1.0 He3 puff 90V 0.5-0.55sec, 50V 0.55-0.9sec D & E trippin |
| May 10 1995 05:54:26:980PM | 950510012 | Yuichi Takase | shot 012: 6.5T, 0.8MA
fixed outer gap excursion, R_gap=1.5cm |
| May 10 1995 05:54:45:950PM | 950510013 | Yuichi Takase | shot 013: 6.5T, 0.8MA
larger outer gap, R_gap=2.3cm |
| May 10 1995 05:55:06:600PM | 950510014 | Yuichi Takase | shot 014: 6.5T, 0.8MA
still having trouble running both antennas together (cross-talk) E-port only this time |
| May 10 1995 05:55:25:550PM | 950510015 | Yuichi Takase | shot 015: 6.5T, 0.8MA
D-port only (giving up on two antenna operation for today) R_gap=1.6->1.2cm |
| May 10 1995 05:55:43:080PM | 950510016 | Yuichi Takase | shot 016: 6.5T, 0.8MA
R_gap=1.3cm, P_D=0.5-1.5MW |
| May 10 1995 05:55:58:500PM | 950510017 | Yuichi Takase | shot 017: 6.5T, 0.8MA
same, McPherson not working for 15, 16, 17 |
| May 10 1995 05:56:23:380PM | 950510018 | Yuichi Takase | shot 018: 6.5T, 0.8MA
start He3 scan He3 puff 90V 0.5-0.55sec, 50V 0.55-0.9sec, HeII(304)=5, Te0(max)=2.5keV |
| May 10 1995 05:56:39:720PM | 950510019 | Yuichi Takase | shot 019: 6.5T, 0.8MA
no He3 puff, HeII(304)=3, Te0(max)=2.0keV |
| May 10 1995 05:56:57:760PM | 950510020 | Yuichi Takase | shot 020: 6.5T, 0.8MA
no He3 again, HeII(304)=2, Te0(max)=2.0keV |
| May 10 1995 05:57:12:610PM | 950510021 | Yuichi Takase | shot 021: 6.5T, 0.8MA
He3 90V 0.5-0.53sec, 40V 0.53-0.9sec, HeII(304)=3-4, Te0(max)=2.2keV |
| May 10 1995 05:57:38:340PM | 950510022 | Yuichi Takase | shot 022: 6.5T, 0.8MA
He3 90V 0.5-0.57sec, 60V 0.57-0.9sec, HeII(304)=4-11, Te0(max)=2.2keV short RF |
| May 10 1995 05:58:02:820PM | 950510023 | Yuichi Takase | shot 023: 6.5T, 0.8MA
lowered initial density, He3 90V 0.5-0.57sec, 55V 0.57-0.9sec, HeII(304)=5-8, no R |
| May 10 1995 05:58:42:060PM | 950510024 | Yuichi Takase | shot 024: 6.5T, 0.8MA
OH2 adjustment before this shot He3 90V 0.5-0.57sec, 40V 0.57-0.9sec |
| May 10 1995 05:59:00:580PM | 950510025 | Yuichi Takase | shot 025: 6.5T, 0.8MA
same, some RF from D & E, HeII(304)=4, Te0(max)=3keV |
| May 10 1995 05:59:17:650PM | 950510026 | Yuichi Takase | shot 026: 6.5T, 0.8MA
same, D-port OK, HeII(304)=4, Te0(max)=3.0keV |
| Physics Operator Comments |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:18:15:540AM | Test | Ok | tf current limit test |
| 2 | 08:29:04:910AM | Plasma | Ok | alt fault after shot |
| 3 | 08:41:36:240AM | Plasma | Ok | |
| 4 | 08:54:45:240AM | Plasma | Ok | |
| 5 | 09:16:26:170AM | Plasma | Ok | |
| 6 | 10:10:57:630AM | Plasma | Ok | |
| 7 | 10:32:57:180AM | Plasma | Ok | |
| 8 | 10:54:44:080AM | Plasma | Ok | |
| 9 | 11:14:52:290AM | Plasma | Ok | |
| 10 | 11:44:22:700AM | Plasma | Ok | |
| 11 | 12:04:35:450PM | Plasma | Ok | |
| 12 | 12:22:09:530PM | Plasma | Ok | |
| 13 | 12:45:39:720PM | Plasma | Ok | |
| 14 | 01:05:29:550PM | Plasma | Ok | |
| 15 | 01:21:52:340PM | Plasma | Ok | No Faults. |
| 16 | 01:40:37:190PM | Plasma | Ok | No Faults |
| 17 | 02:03:18:650PM | Plasma | Ok | No Faults. |
| 18 | 02:19:52:530PM | Plasma | Ok | No Faults. |
| 19 | 02:41:49:750PM | Plasma | Ok | No Faults. |
| 20 | 03:03:02:140PM | Plasma | Ok | No Faults. |
| 21 | 03:19:34:860PM | Plasma | Ok | No Faults. |
| 22 | 03:36:45:230PM | Plasma | Ok | NO Faults. |
| 23 | 03:59:30:340PM | Plasma | Ok | No Faults. |
| 24 | 04:16:37:350PM | Plasma | Ok | NO Faults. |
| 25 | 04:33:41:360PM | Plasma | Ok | No Faults. |
| 26 | 04:51:29:840PM | Plasma | Ok | No Faults. |