| Miniproposals | ||||||||||
|
| Operators | |
| Session leader(s): | Martin Greenwald |
| Physics operator(s): | Ian Hutchinson |
| Engineering operator(s): | Vinny Bertolino,Joe Daigle |
| Engineering Operator Run Comment |
| alcator c |
| Session Leader Plans |
| Physics Operators Plans |
| Session Leader Summaries |
| Entered: Jul 7 2004 03:49:14:600PM |
| Author: To Be Determined |
| Run Plan for Ohmic Confinement Studies - 951207 ----------------------------------------------- Toroidal Field: 5.2 Plasma Current: 0.5-1.0 MA Working gas species: D2 This run is aimed toward completing the data set for low density ohmic confinement. All the shots should be at 5.2T in D2; R and a are in the normal range, .67-.68 and .22-.23 respectively. If possible all shots should be limited on the inner wall. The scans we need to do are: a. scan density at kappa = 1.6-1.7, Ip = .5 MA ~ 8 shots nebar from .4-1.5e20 with emphasis on lower densities b. scan density at kappa = 1.3-1.35, Ip = .5 MA ~ 8 shots nebar from .4-1.5e20 with emphasis on lower densities c. scan kappa and Ip at constant q95 ~ 4. and constant nebar = .6-.7e20; ~ 6 shots The kappa's we're looking for are: 1.3, 1.5, and 1.7 at q95 ~ 4 this corresponds to Ip ~ .65, .75, and .9 MA Overall this run was fairly successful with 27 good shots; all of scan a and b were completed and 2 of the 3 conditions in scan C were obtained. Shots suitable for further analysis include: Shot Ip kappa nebar q95 Comment 004 .54 1.6 1.1 006 .52 1.4 1.3 008 .53 1.57 1. 010 .5 1.58 .75 Start of density scan a. 011 .5 1.58 .5 012 .5 1.58 .5 013 .5 1.58 .25 Synchrotron radiation seen 014 .51 1.58 .6 end scan a. 015 .51 1.37 .73 016 .51 1.34 .64 Start of density scan b. 017 .51 1.34 .74 018 .51 1.34 .45 019 .51 1.34 .5 020 .51 1.35 .42 021 .51 1.34 .25 022 .51 1.34 .4 023 .51 1.34 .74 024 .51 1.34 1.0 end scan b. 025 Fiducial Shot 026 .51 1.34 1.0 027 .65 1.3 1.0 4.0 028 .65 1.3 1.0 4.0 029 .65 1.3 .72 4.0 scan c. 030 .65 1.3 .61 4.0 scan c. 031 .65 1.45 .64 4.7 032 .8 1.45 .64 4.0 scan c. 036 .88 1.57 .6 4.2 scan c. Shot Ip kappa nebar q95 Comment |
| Physics Operator Summaries |
| Entered: Jul 7 2004 04:36:55:537PM |
| Author: To Be Determined |
| Physop 951207 MP 92. Confinement Studies of Alcator C-like plasmas Continued. _______________________________________________________ SL Greenwald PO hutch EO Bertolino, Daigle The whole run plan was achieved although the final high-current high-elongation plasma disrupted near the end. Elongations up to 1.8 of limited plasmas were obtained. See Greenwald's report for confinement. This run was carried out under KAPPA control, predominantly by changing the predictor reference points rather then the drawn offset. The controller was not changed. The general trend was correct but the callibration was not quite what one might expect. Using symmetric ztop, zbot, the observed elongations were roughly as in the following ``calibration''. ztop(m) actual kappa nominal kappa .36 1.8 1.57 .35 1.6-1.7 1.52 .34 1.53 1.48 .32 1.45 1.4 .30 1.35 1.3 .29 1.33 1.26 A very good sequence of 24 consistent plasmas was obtained. Finally marred by a disruption due to over-ambition on the part of the physop. Details _______ Loaded shot 950606020. Did all the EF2,EF4,EF2_by_EF4 factor adjustments. Loaded into model. Tried to load segment 1 from yesterday. PCS crashed. Wolfe suggests this was operator error not filling in the segment box. Saved for safety in user10:[hutch.mds.predictor.pcs] shot 120701. Verified that it could be got back. Lower EF4 to 1090A as per 950606021. Realized we need the pulsed fill. Saved as 120702. Loaded from 951206040. Pulse was [-.515,-.499]sec on puse gas 4. Pulse gas 3 had points at (0,100), (.01,25). Reloaded 120702 Added a gas 4 pulse as per above. Adjusted the Pulse gas 3. Adjusted the kappa controller to ztop=.35m, zbot=-.35. Kappa reference is 1.52. Drawn zero offset. Had to change factor to 2e-6. Got an error on load about the kappa predictor. Had to lower the time constant to 1.5 from 2+. 1 Dud No bus rogowski data, but no EF3,4 or EFC. Chopper looks bad. There was a problem with the UPS this morning. It was determined that some strange numbers were loaded incorrectly on loading the old shot. Chopper had blown fuse on controller board. 2 Pla Plasma thrown upward at segment switch. Kappa controller gain down to 1 at seg switch. Steps up to 6. RXL gain to .5 at switch, 2 at .3s. ZXL to 1 at switch. 5 at.3s. Same for RXU,ZXU. Ask for chopper to come on at .005s (vs .06s) 3 Pla Disrupts down at 2.4s. Seems to be a vertical instability at n/ncrit=1.3. due to trying for too much kappa with high triangularity. Returned RXL and ZXL gains to 2. (Ps are zero) Kappa set integral gain to 0 from 2. Draw -.1. 4 Pla Looked like a divertor on the TV. Ran to 1.05s. 7e19 nl04. Actually got nice high elongation 1.6-1.7 just limited. Unstable at the end because of too much elongation. Draw Rcur to .663 from .25s. Kappa draw ramp to +.6 starting at .75s. ZXl,ZXU at at .06 this is the biggest poss without factor tweaks. Dropped OH1V to 100V during flat-top. 5 Fiz High Carbon. 30kA Late breakdown, 6.5ms. Ratiomatic 1.36e-5 at t=0. Add 1ms to fill-puff. 6 Pla Disrupts at .9s. Realised the kappa ramp was in the wrong direction. Hardly changed the ratiomatic at fill. Drew kappa to 0 and ramped NEGATIVE. Dropped gas V during the plasma. 7 Fiz Late breakdown, high carbon. Ratiomatic 1.44e-5. Added 2ms to fill-puff. 8 Pla Ramped down. Big excursion on EF2s starts at .3s. Probably ZXs. Elongation ramp at end works. Put zx gains to 3 at .17s Lowered Ip to .48MA Move RCur out a little earlier. Density to 5.e19. 9 Fiz Density scan at k=1.6 EF4 to 1105A. (-15). 10 Pla Good nl04 to 3e19. Kappa to -.3 at .1s. Delayed ramp to .85s. 11 Pla Good Nl04 to 2.5e19. EF4 V removed step at .2s to avoid back swing. 12 Pla Got 2.7 nl nl02 to 2.e19. Small tweak to bring Ip down faster. 13 Pla Runaway synchrotron radiation seen on the left. Got 2.18 e19. .3 roentgen. nl04 to 4.e19. 14 Pla Start density scan at k=1.3 Set kappa reference point to .28m. Called. Says reference kappa 1.22 Set kappa ref to .30m. Called. Ref kappa=1.3. Drew zero. 15 Pla Got Kappa ~ 1.35. Individual gas chops show relaxation on pi bolo etc. Set kappa refs to .29m. Called. Nominal Ref 1.26. 16 Pla Got kappa ~ 1.33. nl04 to 3e19. 17 Pla Still no runaways. Got 4.5e19. Forgot to load, hence a repeat. Load this time. Tweak at current end: removing faster slope late. 18 Pla Got 3.5e19. Set nl04 2.5e19. Reduced the Rcur ramp rate after 1.33s. 19 Pla Got 3.3e19. Gas puff comes on a bit too strong at regulation. Set nl04 2e19. Tweaked rcur ramp. 20 Pla Some xrays on TV. No synchrotron emission. Set 1.8e19. Rcur tweaked som more at end. 21 Pla Got 2e19, .099 Roentgens. Rcur is not repondin to the tweaks. It is impossible to keep it out. Set nl04 1.5e19. Rcur to .66 at 1.5s. 22 Pla Xrays, no synchrotron. 1.8e19. Disrupts with nice frame on TV. RCUR A-out indicates that it is following demand at about -1000 at 1.5s. There is 8000 offset in this predictor. Segment 1 has 10000 offset. These offset jumps might be the cause of the excursions at segment switch. Set nl04 4.5e19. Drew rcur offset to 10000 in segment 2 (from 8000). 23 Pla Did not correct Rcur much. Perhaps did not take. Got 4.6e19. Rcur=.658m during flat top. nl04 to 6.e19. The rcur offset appeared not to be changed. Set rcur offset to 10000 again! 24 Pla If anything rcur moves inward more. Rcur =.654m during flat top. Got 6.6e19. Fiducial Load 951205025 for fiducial. It has 10000 and 8000 Rcur offsets. 25 Pla load 951207024. offset back to 8000. takes. 26 Pla This has its rcur in the same place as the others. hence it is a better part of the scan than 24. Start of kappa scan at constant q_95. Ip to .65MA. Drew kappa to -.03 (refs .29). nl04 3.7e19. 27 Pla Runaway burst early. But recovers. Density a bit high. Moly 6e15. Introduce a predictor RCUR switch at 1.1s to fluxihh with 4000 offset. Draw a .5cm inward RCUR step to compensate. Ef4 to 1100A (-5). nl04 3.3e19 28 Pla Thermal. RCUR error steps to -3000 at 1.1s. Got 4.1e19. .666MA. q_95=4.0 Remove the rcur step at 1.1 (but leave predictor switch) nl04 to 3.1 and slightly longer initial ramp. 29 Pla RCUR shows a step at 1.1s. nl04 to 3.0e19 and a slower ramp from .2s. RCUR offset to 0 at 1.1s. -1 cm step drawn. 30 Pla Clear signs that we are getting the rcur under control in ramp-down. However, no improvement in the length before disruptions. Kappa predictor ztop to .32m, reference kappa 1.4. nl04 to 4e19. kept nl04 up in final current ramp. Forgot the 800kA 31 Pla Kappa about 1.45 but only .65MA. Load Ip= .8mA nl04 to 3.5e19 32 Pla Got 4.3e19. q_95=4.0 OK. Kappa ztop to .36m, reference kappa=1.57 set factor to 1.6. Ip to .875MA. Kept the ramp-down fast late. Moved kappa gain beyond 1.5s nl04 to 4.e19 Got bit errors from the load. Put time constant to 1.3 to prevent the OH2 lines overloading. Accidentally called the controller. 33 Pla Disrupts at .65s. EF2(6kA) and EF3(10.5kA) railing at .4s. Got kappa=1.7 kappa ztop to .34s. Ref kappa 1.48. IC_EF4 program to maximize ramp rate and reach 2.4kA. Slowed the final ramp to .875MA till .5s. EF3 current limit to 14kA from 12kA. 34 Fiz Carbon .038!!. Lower V_OH1 by 50V to 40V at -.01s 35 Fiz Carbon .033. 30kA at .011s. Lowered .005s OH1 V also by 50V to 80V. 36 Pla Disrupts at .9s. q_95 only reaches 4.1 at the end otherwise too high. Mo rather high all the way through. Looks like a brick. Survives the railing of EF2s from which we emerge at .5s. Ip to .9MA Various Kappa tweaks. Dropped zx gains at .3s to 3. 37 Fiz Scorecard _________ Shot,Duration(s),Ipmax(MA) Shot,Duration(s),Ipmax 1 0.000 0.013 2 0.135 0.517 3 0.234 0.631 4 1.048 0.553 5 0.000 0.029 6 0.972 0.576 7 0.000 0.029 8 1.492 0.543 9 0.000 0.029 10 1.488 0.527 11 1.486 0.517 12 1.480 0.509 13 1.484 0.507 14 1.474 0.517 15 1.451 0.512 16 1.463 0.514 17 1.462 0.517 18 1.530 0.512 19 1.522 0.507 20 1.516 0.512 21 1.513 0.512 22 1.525 0.507 23 1.551 0.515 24 1.535 0.517 25 1.527 0.838 26 1.557 0.527 27 1.479 0.672 28 1.514 0.670 29 1.507 0.670 30 1.526 0.664 31 1.526 0.677 32 1.512 0.814 33 0.615 0.967 34 0.000 0.021 35 0.000 0.026 36 0.896 0.969 37 0.000 0.026 Finished summary for 951207 Total of 37 shots. 37 shots. 30 plasmas. 6 fizzles. 1 duds. Fizzle = gt 17 lt 50kA. |
| Session Leader Comments | |||
| Dec 7 1995 08:45:54:900AM | Martin Greenwald | Run Plan for Ohmic Confinement Studies - 951207
----------------------------------------------- Toroidal Field: 5.2 Plasma Current: 0.5-1.0 MA Working gas species: D2 This run is aimed toward completing the data set for low density ohmic confinement. All the shots should be at 5.2T in D2; R and a are in the normal range, .67-.68 and .22-.23 respectively. If possible all shots should be limited on the inner wall. The scans we need to do are: a. scan density at kappa = 1.6-1.7, Ip = .5 MA ~ 8 shots nebar from .4-1.5e20 with emphasis on lower densities b. scan density at kappa = 1.3-1.35, Ip = .5 MA ~ 8 shots nebar from .4-1.5e20 with emphasis on lower densities c. scan kappa and Ip at constant q95 ~ 4. and constant nebar = .6-.7e20; ~ 6 shots The kappa's we're looking for are: 1.3, 1.5, and 1.7 at q95 ~ 4 this corresponds to Ip ~ .65, .75, and .9 MA | |
| Dec 7 1995 08:47:38:250AM | 951207001 | Martin Greenwald | Dud - massive power system and camac problems - may be ups related
|
| Dec 7 1995 09:39:18:740AM | 951207002 | Martin Greenwald | disrupted at .14 seconds
|
| Dec 7 1995 10:01:30:850AM | 951207003 | Martin Greenwald | disrupted at .23 seconds - some progress!
|
| Dec 7 1995 10:28:06:420AM | 951207004 | Martin Greenwald | good plasma, disrupts after 1 second
limited during most of flat-top Ip = .54 MA nebar = 1.1 kappa = 1.6 |
| Dec 7 1995 10:41:51:180AM | 951207005 | Martin Greenwald | fizzle
|
| Dec 7 1995 10:53:45:620AM | 951207006 | Martin Greenwald | OK shot, disrupts at 1 second
Ip = .52 kappa = 1.4 (ramps to 1.9 near end) nebar = 1.3 |
| Dec 7 1995 11:03:32:520AM | 951207007 | Martin Greenwald | fizzle
|
| Dec 7 1995 11:17:25:680AM | 951207008 | Martin Greenwald | good shot - ramps all the way down
flat top with: Ip = .53 nebar = 1. kappa = 1.57 |
| Dec 7 1995 11:46:11:170AM | 951207009 | Martin Greenwald | fizzle
|
| Dec 7 1995 11:45:50:220AM | 951207010 | Martin Greenwald | good shot - ramps all the way down
flat top with: Ip = .5 nebar = .75 kappa = 1.6 |
| Dec 7 1995 11:56:21:960AM | 951207011 | Martin Greenwald | good shot
Ip = .5 kappa = 1.58 nebar = .5 |
| Dec 7 1995 12:10:17:190PM | 951207012 | Martin Greenwald | good shot
Ip = .5 kappa = 1.58 nebar = .5 |
| Dec 7 1995 12:21:24:730PM | 951207013 | Martin Greenwald | good shot
Ip = .5 kappa = 1.58 nebar = .24 |
| Dec 7 1995 12:33:52:210PM | 951207014 | Martin Greenwald | good shot
Ip = .51 kappa = 1.58 nebar = .6 |
| Dec 7 1995 12:49:35:570PM | 951207015 | Martin Greenwald | good shot
Ip = .51 kappa = 1.37 nebar = .73 |
| Dec 7 1995 01:01:58:770PM | 951207016 | Martin Greenwald | good shot
Ip = .51 kappa = 1.34 nebar = .64 |
| Dec 7 1995 01:11:49:950PM | 951207017 | Martin Greenwald | good shot
Ip = .51 kappa = 1.34 nebar = .74 |
| Dec 7 1995 01:19:08:190PM | 951207018 | Martin Greenwald | good shot
Ip = .51 kappa = 1.34 nebar = .45 |
| Dec 7 1995 01:28:51:370PM | 951207019 | Martin Greenwald | good shot
Ip = .51 kappa = 1.34 nebar = .5 |
| Dec 7 1995 01:40:11:390PM | 951207020 | Martin Greenwald | good shot
Ip = .51 kappa = 1.35 nebar = .42 |
| Dec 7 1995 01:52:41:940PM | 951207021 | Martin Greenwald | good shot
Ip = .51 kappa = 1.34 nebar = .25 |
| Dec 7 1995 02:08:21:660PM | 951207022 | Martin Greenwald | good shot
Ip = .51 kappa = 1.34 nebar = .4 |
| Dec 7 1995 02:09:35:200PM | 951207022 | Martin Greenwald | good shot
Ip = .51 kappa = 1.34 nebar = .4 |
| Dec 7 1995 02:19:05:530PM | 951207023 | Martin Greenwald | good shot
Ip = .51 kappa = 1.34 nebar = .74 |
| Dec 7 1995 02:30:18:620PM | 951207024 | Martin Greenwald | good shot
Ip = .51 kappa = 1.34 nebar = 1. |
| Dec 7 1995 02:43:52:970PM | 951207025 | Martin Greenwald | fiducial shot
|
| Dec 7 1995 02:50:02:970PM | 951207026 | Martin Greenwald | good shot
Ip = .51 kappa = 1.34 nebar = 1.0 |
| Dec 7 1995 03:09:29:140PM | 951207027 | Martin Greenwald | good shot - first real try for constant q scan
Ip = .65 kappa = 1.3 nebar = 1.0 q95 = 4 |
| Dec 7 1995 03:09:11:160PM | 951207028 | Martin Greenwald | good shot - first real try for constant q scan
Ip = .65 kappa = 1.3 nebar = 1.0 q95 = 4 |
| Dec 7 1995 03:25:08:990PM | 951207029 | Martin Greenwald | good shot
Ip = .65 kappa = 1.3 nebar = .72 q95 = 4 |
| Dec 7 1995 03:40:33:170PM | 951207030 | Martin Greenwald | good shot
Ip = .65 kappa = 1.3 nebar = .61 q95 = 4 |
| Dec 7 1995 03:55:31:350PM | 951207031 | Martin Greenwald | good shot - but wrong Ip
Ip = .65 kappa = 1. nebar = .64 q95 = 4.7 |
| Dec 7 1995 03:57:40:430PM | 951207031 | Martin Greenwald | good shot - but wrong Ip
Ip = .65 kappa = 1.45 nebar = .64 q95 = 4.7 |
| Dec 7 1995 04:03:56:440PM | 951207032 | Martin Greenwald | good shot - but wrong Ip
Ip = .8 kappa = 1.45 nebar = .64 q95 = 4. |
| Dec 7 1995 04:11:49:390PM | 951207032 | Martin Greenwald | good shot
Ip = .8 kappa = 1.45 nebar = .64 q95 = 4. |
| Dec 7 1995 04:22:57:720PM | 951207033 | Martin Greenwald | Disrupts at .7 sec
|
| Dec 7 1995 04:32:37:670PM | 951207034 | Martin Greenwald | fizzle
|
| Dec 7 1995 04:52:56:680PM | 951207035 | Martin Greenwald | fizzle
|
| Dec 7 1995 04:56:55:380PM | 951207036 | Martin Greenwald | disrupts at .9 sec
Ip = .88 nebar = .6 kappa = 1.57 qpsi = 4.2 |
| Dec 7 1995 05:03:17:430PM | 951207037 | Martin Greenwald | fizzle
|
| Physics Operator Comments |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:39:19:710AM | Plasma | Bad | ef4,ef3,efc did not fire |
| 2 | 09:32:15:100AM | Plasma | Ok | |
| 3 | 09:52:57:490AM | Plasma | Ok | |
| 4 | 10:12:43:340AM | Plasma | Ok | |
| 5 | 10:35:28:780AM | Plasma | Ok | |
| 6 | 10:44:47:710AM | Plasma | Ok | |
| 7 | 10:58:46:280AM | Plasma | Ok | |
| 8 | 11:06:56:550AM | Plasma | Ok | |
| 9 | 11:28:35:140AM | Plasma | Ok | |
| 10 | 11:36:32:520AM | Plasma | Ok | |
| 11 | 11:47:08:780AM | Plasma | Ok | |
| 12 | 11:59:26:700AM | Plasma | Ok | |
| 13 | 12:11:33:360PM | Plasma | Ok | |
| 14 | 12:25:04:260PM | Plasma | Ok | |
| 15 | 12:39:26:050PM | Plasma | Ok | |
| 16 | 12:51:35:570PM | Plasma | Ok | |
| 17 | 01:02:16:110PM | Plasma | Ok | |
| 18 | 01:10:01:080PM | Plasma | Ok | |
| 19 | 01:20:30:860PM | Plasma | Ok | |
| 20 | 01:31:15:080PM | Plasma | Ok | |
| 21 | 01:42:48:170PM | Plasma | Ok | |
| 22 | 01:54:00:270PM | Plasma | Ok | |
| 23 | 02:09:21:960PM | Plasma | Ok | |
| 24 | 02:19:24:990PM | Plasma | Ok | |
| 25 | 02:32:05:650PM | Plasma | Ok | |
| 26 | 02:40:55:730PM | Plasma | Ok | |
| 27 | 02:57:16:220PM | Plasma | Ok | |
| 28 | 03:08:07:960PM | Plasma | Ok | |
| 29 | 03:18:33:770PM | Plasma | Ok | |
| 30 | 03:31:00:370PM | Plasma | Ok | |
| 31 | 03:43:12:620PM | Plasma | Ok | |
| 32 | 03:56:50:880PM | Plasma | Ok | |
| 33 | 04:14:12:700PM | Plasma | Ok | |
| 34 | 04:31:01:600PM | Plasma | Ok | |
| 35 | 04:39:52:660PM | Plasma | Ok | |
| 36 | 04:47:48:060PM | Plasma | Ok | |
| 37 | 05:00:17:780PM | Plasma | Ok | |