| Miniproposals | ||||||||||
|
| Operators | |
| Session leader(s): | Jim Irby |
| Physics operator(s): | Ron Parker,Ron Parker,Jim Irby,Jim Irby,Ron Parker |
| Engineering operator(s): | |
| Engineering Operator Run Comment |
| Plasma Startup and Conditioning/Cochran |
| Session Leader Plans |
| Entered: Feb 7 2005 11:47:16:880AM |
| Author: Jim Irby |
| We will continue plasma conditioning today. Start from 1050204013 (the 150 ms, 500 kA shot from Friday) There will still be no density feedback today. I suggest we puff gas for 20 or 30 ms and then run off whatever comes out of the walls. Object is to get full length low density shots. We should keep plasma current low until we are happy with OH2L coax resistance. Delays should remain on TF and OH supplies to keep double swing in OH2L. Shot 1 should be a data system test We should do a very complete cell check since lots of work has been going on in the cell. |
| Physics Operators Plans |
| Entered: Feb 7 2005 12:41:37:427PM |
| Author: Ron Parker |
| The run today will have plasma conditioning as its goal. We will start from a shot last Friday, 1050204013. There will be no density feedback; instead we'll use preprogrammed gas puff. Our objective will be to get full length low density shots, ideal for LHCD. Shot 1 will test the data system |
| Session Leader Summaries |
| Entered: Feb 8 2005 09:57:51:350AM |
| Author: Jim Irby |
| Primary task for today was to run the machine and continue plasma cleanup. We got one 1.3 s, 550 kA discharge today (shot 22), and one 0.4 s discharge (shot 18). Plasmas are still very dirty (ciii high after first 400 ms discharge) and h/(h+d) is around 50%. We will discharge clean tonight and conditions should be better tomorrow. |
| Physics Operator Summaries |
| Entered: Feb 7 2005 07:10:34:613PM |
| Author: Ron Parker |
| The run was devoted simply to cleaning up the machine and producing decent plasmas. There were 23 shots of which 4 were cycle shots. All attempts at plasma broke down (no duds), but only 5 shots produced substantial currents. The best shot of the day was #22 which lasted for 1.25 s with a current of 550 kA. This shot ran entirely on wall-produced gas (except for the prefill). In general, the tuning of the BR and BV was not particularly fruitful; breakdown could be produced as early as ~ 4.5 ms, but the better discharges, such as they were, were produced with later breakdown ~ 5.5 ms. Clearly, the result of a long lasting shot is to produce loosely boundcimpurities for subsequent shots that prevent burnthrough. Patience is required. |
| Session Leader Comments | |||
| Feb 7 2005 11:59:49:287AM | Jim Irby | We were unable to move the neuts/hards into position in time for the run today. Will have it ready to go for tomorrow. Matt thinks the 2Pi diode and foil will be operational today. The foil will not be calibrated, but Matt will check on it tonight. He also expects the diode array to be operational. We will not have density feedback. Earl has hooked up the H/D fiber, the single chord VB, and the DALSA. | |
| Feb 7 2005 12:07:51:910PM | Jim Irby | GV1 and GV2 will close at pulse for 300 s. SV3 open, SV4 at 200 clicks | |
| Feb 7 2005 12:48:50:460PM | 1050207001 | Jim Irby | Cycle test okay except we were missing all the oh_coax instrumentation data. Found crate offline. With Josh's help we got it back online. |
| Feb 7 2005 01:22:02:270PM | 1050207002 | Jim Irby | Another data system check to make sure the oh coax instrumentation is ready to go. result: OH instrumentation is now okay, but sparker signal started too early?? |
| Feb 7 2005 01:52:56:660PM | 1050207004 | Jim Irby | sparker signals okay now. ready for shot when Steve is satisfied with the DPCS and magnetics signals. Steve ready with DPCS; ready for shot (13:35) bright flash: fizzle |
| Feb 7 2005 02:26:41:020PM | 1050207005 | Jim Irby | fizzle |
| Feb 7 2005 02:26:52:600PM | 1050207006 | Jim Irby | fizzle |
| Feb 7 2005 03:03:57:723PM | 1050207007 | Jim Irby | plasma Earl does have h/d running. About 25% |
| Feb 7 2005 03:25:06:147PM | 1050207008 | Jim Irby | cycle test |
| Feb 7 2005 03:36:14:460PM | 1050207009 | Jim Irby | fizzle |
| Feb 7 2005 04:11:43:537PM | 1050207010 | Jim Irby | fizzle |
| Feb 7 2005 04:12:05:647PM | 1050207011 | Jim Irby | fizzle |
| Feb 7 2005 04:12:12:677PM | 1050207012 | Jim Irby | fizzle |
| Feb 7 2005 04:32:53:863PM | 1050207012 | Jim Irby | fizzle |
| Feb 7 2005 04:48:08:820PM | 1050207014 | Jim Irby | fizzle OH2L below 2 uohms for the first time. |
| Feb 7 2005 05:05:51:677PM | 1050207015 | Jim Irby | Ron has reloaded shot 7. Plasma |
| Feb 7 2005 06:37:59:320PM | 1050207022 | Jim Irby | plasma for 1.3 s, 550 kA h/(h+d) 50% |
| Feb 7 2005 06:46:34:193PM | 1050207023 | Jim Irby | fizzle |
| Physics Operator Comments | |||
| Feb 7 2005 01:39:30:100PM | 1050207001 | Ron Parker | First shot was a cycle test. |
| Feb 7 2005 01:39:52:270PM | 1050207002 | Ron Parker | Shot 2 was a cycle test. |
| Feb 7 2005 01:41:32:863PM | 1050207003 | Ron Parker | Shot 3 was a cycle test, hopefully the last for now. |
| Feb 7 2005 01:51:46:210PM | 1050207004 | Ron Parker | Shot 4 had a small flash, technically a fizzle. BR was about 1.5 mT (+) at breakdown, so this was reduced by 0.0005 T for next shot. |
| Feb 7 2005 03:16:10:960PM | 1050207005 | Ron Parker | Shot 5 was about the same as shot 4, although BR was < 0.5 mT at breakdown. We'll try the gas next, reducing the preprogrammed pulse to 20 ms from 25 |
| Feb 7 2005 02:20:03:723PM | 1050207006 | Ron Parker | Shot 6 was similar to previous shots, althought the H-alpha signal was lower by 10-15%, consistent with the lower fill pressure. Nevertheless, there was no indication of a longer survival. Consensus seems to be that BR should be more negative yet at breakdown, so for next shot BR will be reduced by 0.5 mT (i.e., set at -1.0 mT) |
| Feb 7 2005 03:11:29:257PM | 1050207007 | Ron Parker | Success on shot 7 -- pulse lasted 300 msec @ ~ 500 kA. Density rises steadily to n_eL(4) ~ 1.e20 m-2. Shot 8: similar settings, but Segment 2 PG3 gas reduced to zero after 200 ms. Oops -- more computer system problems. Shot 8 will be a shot cycle. |
| Feb 7 2005 03:23:30:553PM | 1050207008 | Ron Parker | Shot 8 was a shot cycle. |
| Feb 7 2005 03:28:21:630PM | 1050207009 | Ron Parker | Shot 9 was a fizzle. The gas will be slightly reduced (~ 10%) for next shot. |
| Feb 7 2005 03:47:05:270PM | 1050207010 | Ron Parker | Shot 10 still fizzled, apparently choking on impurities. We'll continue to reduce gas fill (2 ms) and also lower BR by 1 mT. |
| Feb 7 2005 04:04:00:677PM | 1050207011 | Ron Parker | Shot is still fizzling. Is Bz too positive? Lower by 20 A. |
| Feb 7 2005 04:27:13:100PM | 1050207012 | Ron Parker | Plasma breakdown is early, ~ 5ms, but current does not rise. Carbon signal increased on that shot compared to shot 11. |
| Feb 7 2005 04:32:57:320PM | 1050207013 | Ron Parker | No change, no difference in result. Still very resistive. Breakdown is early and reliable but current doesn't rise rapidly enough. Same settings. |
| Feb 7 2005 04:35:58:660PM | 1050207014 | Ron Parker | Shot 14 was more of the same. Reload shot 7. |
| Feb 7 2005 04:53:58:693PM | 1050207015 | Ron Parker | We got some current. Still a ratty discharge, particularly after 70 ms, but current made it to 300 kA. Later breakdown by about 2 ms seems to help. Keep trying. |
| Feb 7 2005 05:13:40:363PM | 1050207016 | Jim Irby | While Ron is at a meeting I'll try PO position repeat of shot 15 fizzle --- ciii high |
| Feb 7 2005 05:23:25:303PM | 1050207017 | Jim Irby | repeat of shot 16 gatevalve-toggle turned off for this shot and next one --- does it help startup? plasma for 80 ms, 230 kA |
| Feb 7 2005 05:40:08:553PM | 1050207018 | Jim Irby | good plasma: 400 ms, 580 kA ciii signal pretty clean and low h/(h+d) 50% gatevalve-toggle off for this shot 2PI diode is working and indicates an injection did us in.. |
| Feb 7 2005 05:43:05:537PM | 1050207019 | Jim Irby | repeat shot 18 gatevalve-toggle disabled fizzle |
| Feb 7 2005 05:58:44:240PM | 1050207020 | Jim Irby | prefill from 20 to 18 ms fizzle --- just noticed that we had pulsed gas #3 on to 400 ms gatevalve-toggle was enabled for this shot |
| Feb 7 2005 06:16:12:863PM | 1050207021 | Jim Irby | pulsed gas #3 zerroed out otherwise repeat of shot 20 forgot to load pulsed gas #3 changes on last shot --- should be okay for next shot |
| Feb 7 2005 06:26:32:130PM | 1050207022 | Ron Parker | Parker back as PO. While gone, skilled tuning by Irby and Wolfe brought plasma to 1.25 s. No gas injected during shot. Repeat on next shot. |
| Feb 7 2005 06:43:20:647PM | 1050207023 | Ron Parker | Shot fizzled, but seems on the verge of burning through. Try again. |
| Feb 7 2005 06:53:34:160PM | 1050207024 | Ron Parker | Shot 24 fizzled. No changes for shot 25. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 12:13:31:257PM | Test | Ok | |
| 2 | 12:48:00:473PM | Test | Ok | Data system test |
| 3 | 01:24:33:990PM | Test | Ok | Data system test |
| 4 | 01:34:40:710PM | Plasma | Ok | |
| 5 | 01:54:25:410PM | Plasma | Ok | |
| 6 | 02:08:50:770PM | Plasma | Ok | |
| 7 | 02:23:31:287PM | Plasma | Ok | |
| 8 | 03:10:02:740PM | Test | Ok | |
| 9 | 03:19:29:943PM | Plasma | Ok | |
| 10 | 03:36:30:460PM | Plasma | Ok | |
| 11 | 03:52:40:240PM | Plasma | Ok | |
| 12 | 04:05:15:757PM | Plasma | Ok | |
| 13 | 04:18:37:410PM | Plasma | Ok | |
| 14 | 04:31:47:020PM | Plasma | Ok | |
| 15 | 04:47:03:257PM | Plasma | Ok | |
| 16 | 05:02:05:210PM | Plasma | Ok | |
| 17 | 05:14:33:630PM | Plasma | Ok | |
| 18 | 05:27:01:223PM | Plasma | Ok | |
| 19 | 05:39:24:647PM | Plasma | Ok | |
| 20 | 05:51:56:833PM | Plasma | Ok | |
| 21 | 06:04:17:350PM | Plasma | Ok | |
| 22 | 06:16:40:787PM | Plasma | Ok | |
| 23 | 06:36:07:770PM | Plasma | Ok | |
| 24 | 06:48:22:460PM | Plasma | Ok | |
| 25 | 07:00:44:473PM | Plasma | Ok | |