| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Peter Oshea |
| Physics operator(s): | Earl Marmar |
| Engineering operator(s): | Unknown |
| Engineering Operator Run Comment |
| marmer |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:15:197PM |
| Author: To Be Determined |
| ***************************** * Run 960215 Modulated RF heating ( Mode Conversion at 6.4 T , H[He3] plasmas ) * Session Leader : O'Shea * Physics Operator : Marmar ***************************** Objective of run is to close out MP 090A by completing a current scan of modulated central mode conversion heating appropriate for transport studies. ************************************* The goal of the run was accomplished (!), with best results indicated below: Central heating: ================= 600 kA : (#15) #16! [fmod = 50Hz], #29 [fmod=70Hz] 1.2 MA : #27 [fmod = 70Hz] Interesting Off axis heating: ============================== 600 kA : #02 Sawtooth supression at ~0.9MW with D-port. #04 Good RF mod with BOTH TRANSMITTERS!!!! (a real coup) Prf ~ 2.4MW, sawteeth are greatly reduced. 1.2 MA #26 Very good RF but off axis heating. ;------------------------------------------------------------------------- Some general comments: 1) The Deuterium concentration was again found to have important effects on the location of the mode conversion layer. Today there was a wide variation in the D/H ratio, generally increasing throughout the day, but jumping just often enough to make it difficult to predict and deal with. ECDC in H dropped levels to as low as 8% early in the day, but it was as high as 33% on shot 21. 2) The University of Maryland spectrograph was successfully used to view Helium levels in the edge. A cross calibration with the McPherson allowed the latter to look elsewhere. Z_67_yag was also useful in determining n_He/ne. 3) At both currents, some very interesting interaction of the RF and sawtooth behaviors were seen. During off axis heating, sawteeth were at times greatly diminished or possibly reduced. 4) More detailed analysis will follow, but some very promising data was obtained for transport studies. Good modulation trains at reasonably high frequencies were obtained. Reduced sawtooth behavior may even make some off axis heating analysis possible. ;--------------------------------------------------------------- A very sketchy outline of the shot sequence is given below: starting at 600 kA: 001 dud 002 good pl pretty good rf. Heating isn't very central, increasing He puff for next shot. 003 Heating is more central, Rf modulation is short. 004 down to 580 off axis...both tx's run together and s.t. almost go away!! going to smaller outer gap and higher He (640) 005 heating is more central but the Rf isn't modulating (only one tx) Earl says "we have 11% nhe/ne +/- 4 % ..." stf is about 240Hz... going to higher He still, out to 680... 006 No rf to speak of, Helium frac looks good, 20-25% but the density is a little high... scaling both H and He down.target on H and pulse width on Helium.... ----waiting for the ln2 to get filled----- i was just noting that i was surprised by the amount of helium i need to get central heating (not there yet)....it seems like it's near the values i was trying for last run when i was assuming very little Deuterium... ....sure enough, Rost puts the upper bound on D fraction to be about 8%, though stats are bad. 007 20% He, spekey RF. 008 25% too high helium (D/H coming up?) no RF mod, trouble running both antennas have gone to only one transmitter have gone to lower He3 011 Rf all trippy, better central heating, though not great.... going to find out for sure where the resonance is by ramping the field. Suspecting that the He is too high, so we're heating on the lowfield side so we should heat during lower field part of the ramp... changed grating to 8.2 for the ramp.... Change theta back!!! done... 012 ramp was over too small a range 013 bigger Tf range (low) 014 bigger Tf range (high) 15 good heating! 16 great heating/mod!! going to 1.1 MA 17 disrupts after RF. Heating was central but no modulation 18 fizzle 19 disrupts early 20 bringing down the He to 60 ms 21 33% D at 0.5 sec...density is a little high...poor rf but heating is at least close to the center bringing it down to 50ms 22 heating was bizarre, though a huge injectin my have been the cause. Somewhat central little confused as to where the heating is....assuming it's at the low field side and so doing a bt ramp up from low fields...(maybe a bad guess b/c ...we'll see either way but the higher fields might be safer with this high current..) 23 Tf ramp to find central heating 24 fizzle 25 plasma, disrupts late 900kA. very nice RF.....heating is pretty central but not amazing...channel positions??? going down in He puff to 30ms 26 nice RF heating is off axis upping freq and He (70 ms) 27 plasma...pretty good heating, if i don't mind saying so myself going back to 16 for a different frequency of mod.... 28 big injection and lousy rf coupling..... retrying.... 29 good 600 kA shot 30 trying an 800 kA shot for contact with history.....no rf |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:36:56:147PM |
| Author: To Be Determined |
| 960215 MP 90A modulated ICRF Attempt to get good modulated H(3He) central electron heating at 0.6 and 1.2 MA Overnight ECDC in H2. Fill A-side (really K-side) to 20psi H2 Fill B-top with 5psi H2 B-side upper He-3 20 PSI The run goals were largely accomplished. The machine ran well, and good RF modulation and heating was achieved at the 2 current levels. 1. start from 960119026; fizzle; looks like B_R offset not positive enough 2. B_R offset to 7.2 mT; plasma 3. extend 1st 3He puff by 20 msec; plasma 4. decrease 3He puff by 40 msec; plasma 5. increase RCUR by 2 mm (to decrease outer gap by 4 mm); add 60 ms to 3He pulse; plasma; see the He now on Z_eff (delta Z ~ .22) 6. increase 3He to .68; lower nl_04 prog before He puff to 7.5e19 from 8.5e19; plasma; delta Z ~ .45 7. decrease 3He to .67; lower nl_04 prog before He puff to 5.5e19; decrease clearin by 4 mm; plasma; delta Z ~ .4 8. move 3He puff 20 msec earlier, decrease width by 10 msec; lower nl_04 prog before He puff to 5.e19; plasma; delta Z ~ .5; a few hards early 9. add post breakdown puff on P_G_4; reduce 3He puff by 15 msec; plasma 10. reduce 3He puff by 15 msec; plasma 11. reduce 3He puff by 15 msec; plasma 12. hybrid control of TF, ramp during RF; plasma 13. change TF ramp; plasma 14. change TF ramp again; plasma 15. TF back on PLC control; 6.4 Tesla; plasma 16. repeat; plasma; nice RF modulation 17. attempt 1.2 MA; import segment 2 from 960119025 into segment 3; tweak RCUR, clearin, nl_04 to match previous shots; increase Ip request to 1.2 MA; plasma; disrupt on rampdown (.8MA); riding the outboard limiter 18. decrease RCUR 5 mm; tweak nl_04 programming; slow RCUR rampdown; strong fizzle (60 kA) 19. add 1 msec to pre-puff; B_R offset to 6.8 mT; plasma; early disrupt; OH2L crowbar at ~0.2 seconds; 20. retry; plasma; 21. lengthen Ip flattop to 1.1 s; reduce 3He puff by 10 msec; plasma 22. reduce 3He puff by 10 msec; plasma 23. TF on hybrid, ramping from 6.0 T at .7 to 6.5 T at 1.1 s; plasma 24. strong fizzle (80 kA) 25. TF on PLC; add 1 msec to prepuff; plasma; plasma; disrupt on ramp-down (.9 MA) 26. reduce 3He by 30 ms; plasma 27. 3He 70 ms puff; plasma 28. back to 600 kA; reload 960215016, using segments 1 and 2; plasma; 29. repeat; plasma 30. 800 kA; load segment 2 from 960119022; match 3He puff and nl_04 program to shot 29; 30 attempts, 27 plasmas, 3 fizzles. From: PHYSOP::MARMAR Date: 15-FEB-1996 17:35:13 Subj: physop run summary 960215 960215 MP 90A modulated ICRF Attempt to get good modulated H(3He) central electron heating at 0.6 and 1.2 MA Overnight ECDC in H2. Fill A-side (really K-side) to 20psi H2 Fill B-top with 5psi H2 B-side upper He-3 20 PSI The run goals were largely accomplished. The machine ran well, and good RF modulation and heating was achieved at the 2 current levels. 1. start from 960119026; fizzle; looks like B_R offset not positive enough 2. B_R offset to 7.2 mT; plasma 3. extend 1st 3He puff by 20 msec; plasma 4. decrease 3He puff by 40 msec; plasma 5. increase RCUR by 2 mm (to decrease outer gap by 4 mm); add 60 ms to 3He pulse; plasma; see the He now on Z_eff (delta Z ~ .22) 6. increase 3He to .68; lower nl_04 prog before He puff to 7.5e19 from 8.5e19; plasma; delta Z ~ .45 7. decrease 3He to .67; lower nl_04 prog before He puff to 5.5e19; decrease clearin by 4 mm; plasma; delta Z ~ .4 8. move 3He puff 20 msec earlier, decrease width by 10 msec; lower nl_04 prog before He puff to 5.e19; plasma; delta Z ~ .5; a few hards early 9. add post breakdown puff on P_G_4; reduce 3He puff by 15 msec; plasma 10. reduce 3He puff by 15 msec; plasma 11. reduce 3He puff by 15 msec; plasma 12. hybrid control of TF, ramp during RF; plasma 13. change TF ramp; plasma 14. change TF ramp again; plasma 15. TF back on PLC control; 6.4 Tesla; plasma 16. repeat; plasma; nice RF modulation 17. attempt 1.2 MA; import segment 2 from 960119025 into segment 3; tweak RCUR, clearin, nl_04 to match previous shots; increase Ip request to 1.2 MA; plasma; disrupt on rampdown (.8MA); riding the outboard limiter 18. decrease RCUR 5 mm; tweak nl_04 programming; slow RCUR rampdown; strong fizzle (60 kA) 19. add 1 msec to pre-puff; B_R offset to 6.8 mT; plasma; early disrupt; OH2L crowbar at ~0.2 seconds; 20. retry; plasma; 21. lengthen Ip flattop to 1.1 s; reduce 3He puff by 10 msec; plasma 22. reduce 3He puff by 10 msec; plasma 23. TF on hybrid, ramping from 6.0 T at .7 to 6.5 T at 1.1 s; plasma 24. strong fizzle (80 kA) 25. TF on PLC; add 1 msec to prepuff; plasma; plasma; disrupt on ramp-down (.9 MA) 26. reduce 3He by 30 ms; plasma 27. 3He 70 ms puff; plasma 28. back to 600 kA; reload 960215016, using segments 1 and 2; plasma; 29. repeat; plasma 30. 800 kA; load segment 2 from 960119022; match 3He puff and nl_04 program to shot 29; plasma 30 attempts, 27 plasmas, 3 fizzles. |
| Session Leader Comments |
| Physics Operator Comments |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:33:33:570AM | Plasma | Ok | |
| 2 | 08:44:42:190AM | Plasma | Ok | |
| 3 | 08:57:13:200AM | Plasma | Ok | |
| 4 | 09:17:49:410AM | Plasma | Ok | |
| 5 | 09:33:36:350AM | Plasma | Ok | |
| 6 | 09:50:21:010AM | Plasma | Ok | |
| 7 | 10:28:41:920AM | Plasma | Ok | |
| 8 | 10:59:54:480AM | Plasma | Ok | |
| 9 | 11:18:16:550AM | Plasma | Ok | |
| 10 | 11:33:41:600AM | Plasma | Ok | |
| 11 | 11:47:35:840AM | Plasma | Ok | |
| 12 | 12:12:19:200PM | Plasma | Ok | |
| 13 | 12:32:00:790PM | Plasma | Ok | |
| 14 | 12:50:54:090PM | Plasma | Ok | |
| 15 | 01:04:37:230PM | Plasma | Ok | |
| 16 | 01:18:59:400PM | Plasma | Ok | |
| 17 | 01:38:06:000PM | Plasma | Ok | Comm Fault OH2l & OH1 |
| 18 | 01:58:03:710PM | Plasma | Ok | |
| 19 | 02:08:43:230PM | Plasma | Bad | Comm fault OH2 U&L EF1 U&L |
| 20 | 02:26:28:470PM | Plasma | Ok | |
| 21 | 02:48:23:450PM | Plasma | Ok | |
| 22 | 03:01:16:020PM | Plasma | Ok | Comm fault Oh2L EF1U & OH1 |
| 23 | 03:24:44:050PM | Plasma | Ok | |
| 24 | 03:40:04:410PM | Plasma | Ok | |
| 25 | 03:50:53:770PM | Plasma | Ok | |
| 26 | 04:05:33:210PM | Plasma | Ok | |
| 27 | 04:18:54:580PM | Plasma | Ok | |
| 28 | 04:28:26:920PM | Plasma | Ok | |
| 29 | 04:44:01:160PM | Plasma | Ok | |
| 30 | 04:58:08:670PM | Plasma | Ok | |