| Miniproposals | ||||||||||||||
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| Operators | |
| Session leader(s): | Amanda Hubbard,Rajesh Maingi,Jerry Hughes |
| Physics operator(s): | Earl Marmar,Steve Wolfe |
| Engineering operator(s): | Andy Pfeiffer,Ed Fitzgerald,Bill Parkin |
| Engineering Operator Run Comment |
| MP 448, Comparison of Small ELM regimes on C-Mod, MAST and NSTX SL: Hubb |
| Session Leader Plans |
| Entered: Apr 6 2006 04:33:24:930PM |
| Author: Amanda Hubbard |
| Run Plan for Part B of 1060407, MP 448, Comparison of Small ELM regimes on C-Mod, MAST and NSTX
Session Leaders: Rajesh Maingi (remote from PPPL) and Amanda Hubbard Physics Operator: Earl Marmar This run is contingent on successful overnight boronization of the vessel on 4/6, and subsequent conditioning of ICRF to at least 3 MW, which is expected to take part of the morning. See Physop Plan for boronization details. Plan: 1. Set up target discharge. Start with shot 1050608018 (LSN, kappa=1.72, delta_l=0.52, delta_u 0.34) but reduce Ip to 730 kA to get q95=5.5, the present lower limit on NSTX. Compare with target and adjust shape and/or q95 as necessary. Use target NL04=7x 1019 m-2, which should give EDA H-mode, and modest ICRF (2-3 MW) for these shots so it can tune up. 4 shots. 2. Power/beta scan. Increase power shot to shot in 0.5 MW increments. Each shot will include two power levels, to reduce total number needed. (2.5 MW, 3 MW, 3.5 MW, 4.0 MW, 4.5 MW, 5.0 MW). Monitor ELM type (expect to start getting ELMy regime) and pedestal beta. Keep RF pulse fairly short (~150 ms per power) to reduce boron erosion but still get good pedestal data. 6 shots. 3. Time permitting, start Density/n* scan. Keeping power, and hopefully beta, in its upper range, scan target density shot to shot to vary nped, Tped and thus n*. Use two power levels per shot, selected based on results of step two. Start by raising target nel (9x 1019 m-2, 1.1x 1020 m-2, 1.3x1020 m-2, 1.5x1020 m-2. Upper limit will probably be set by neutral pressure limit of J-port, or if we are lucky, a transition to Type III ELMs. Then scan downwards, 7x 1019 m-2 ,6x 1019 m-2. The limit in this case will be losing EDA and getting either transient ELM-free H-modes or, more interestingly, discrete Type I ELMs. It is likely this will have to be completed on a second half-day, following NSTX experiments. |
| Physics Operators Plans |
| Entered: Apr 6 2006 04:56:46:213PM |
| Author: Earl Marmar |
| Physop Plan and engineering setup for Friday, April 7, 2006
MP 448, Comparison of Small ELM regimes on C-Mod, MAST and NSTX SL: Hubbard, Maingi PO: Marmar Overnight boronization prior to the run This will be the first full boronization of calendar year 2006. We are using the 20% (B_2D_6)/ 80% He mix. Desired parameters for the boronization: Scan ECDC resonance from 44 cm to 103 cm, dwell at 70 cm 100% duty factor on the microwaves (no pulsing) pressure targets: tc3/tc6/req 5.8/97.5/56 mT boronize until pressure in the bottle has dropped by 60 psi Then ECDC in He-4 for up to 4 hours, stopping by 7:30 am. Power systems as on 1060405023 A-coil configuration: normal [+Dtop -Dbot -Jtop +Jbot] and enabled. C-coil Start=0.3sec, Invert=2.0sec all ICRF systems in run-on by 8:30 am. Gas Setup: ---------- fill B-top 6psi D2 Hybrid enabled (PG4) fill B-side lower 1 psi Argon Hybrid Disabled (PG1) fill B-side Upper as is, Hybrid Disabled (PG2) fill B-main 40psi D2 Hybrid Enabled (PG3) NINJA: 12psi D2 Enable ECE, VUV, Z-bolo shutter assuming no vacuum problems |
| Session Leader Summaries |
| Entered: Apr 7 2006 05:50:36:860PM |
| Author: Amanda Hubbard |
|
Summary of 1060407, MP 448, Comparison of Small ELM regimes on C-Mod, MAST and NSTX Session Leaders: Rajesh Maingi (remote from PPPL) and Amanda Hubbard (MIT) with particpation from Hendrik Meyer (UKAEA) and Jerry Hughes subbing. Physics Operator: Earl Marmar The run was generally quite successful in scoping out the attainable parameters at NSTX/MAST shape and q95, though not in attaining all the values we had hoped. Shots 2-8 were spent at standard 1 MA conditions, to condition RF post-boronization. RF was still somewhat trippy, and H-modes not as steady as one would like; the state of boronization remains to be well analysed. From shot 9 we lowered Ip to 700 kA, got target q95=5.5. Relatively small shape tweaks by Steve Wolfe sufficed to match the NSTX target; match was good by shot 10; (Jerry and Rajesh were filling in for Amanda at this stage). H-mode performance was generally quite good, with H-factors in the range of H89(L)~2 and H98(H) ~ 1, which would indicate good RF absorption and wall conditions. Total power was, however, limited, with P <+ 3 M on most discharges. J-port in particular seemed to trip more as the day progressed. D and E performed better, 1-1.5 MW each. Reproducibly, at lower target densiy (nel 6-7 e19 m-3), a large injection occurred at ~ 0.85 s. (eg shots 16, -18, and 29-33). Variations in the shape did not seem to change this; likely culprit is D antenna. The injections went away at nel target 9e19 m-2 (shots 24-26). Pedestal pressure was limited by available RF, not MHD. Typical values were pe_95 <= 1.1e23 m-3 keV, significantly lower than ideal matching values. (which would have corresponded to ~ 2e23 m-3). This did not vary much with target density, which only weakly affected nped. (We have been working out beta values; will double-check definitions before adding to the run summary). Collisionalities were ~ 1, as desirded, with some range during power and ne scans. Towards the end of the run we tried scoping out more of the oeprationg space at this power, lowering Bt to 5 T (shot 27), reducing Ip to 600 kA (shot 28)., both or which reduced pe,ped to ~ 8e22. Ip was raised to 800 kA on shot 31. The highest pressures of the day were obtained in the last two shots, (32,33h) wen we returned to 700 ka, low target ne and Yjun was able to increase power (3.7 MW max, some trips). Pe,ped was up to 1.38e23, transiently, and there were indications of (quite) small ELMs. These shots will be further analysed and used as targets for next week's NSTX experiment, scheduled for 4/13. |
| Physics Operator Summaries |
| Entered: Apr 7 2006 06:30:57:360PM |
| Author: Earl Marmar |
| This was a relatively straightforward run from the physop point of view. Machine operation recovered quickly from the boronization. Startup was quite reliable, with only minor tweaks to the EF4 current and prefill puff. J-port is still tripping a lot, especially above 1 MW. Tuning the shot for the MP was also straightforward, with slight shape changes using RXL, and current and density scans. At P_RF~3 MW, there were many shots with decent EDA H-modes, but usually they suffered increases in radiated power and degraded confinement after 100 to 200 msec in H-mode. This was worse for the lower target density shots, better for higher target density shots. On many shots, the TV views (particularly wide2) showed bright events from one corner of the D-port antenna, correlating with the times at which P_Rad jumped up in some cases. Three shots (4, 14, 16) disrupted early.
Scorecard: fizzles: 3 dud: 1 plasmas: 29 |
| Session Leader Comments | |||
| Apr 7 2006 11:01:30:183AM | 1060407006 | Amanda Hubbard |
Still doing standard post-boron conditioning and assessment shots. Plasma starts well, 4 MW RF, 166 kJ. But, not so good after the RF trips. Less steady than first few shots. |
| Apr 7 2006 11:07:17:230AM | 1060407007 | test entry again | |
| Apr 7 2006 11:48:34:917AM | 1060407009 | Jerry Hughes | Jerry here, sitting in for Amanda while she attends a conference call.
Ip and target density look about right. RF seems only marginaly happy. Wukitch reports something "goofy" affecting the loading during this shot and the previous. |
| Apr 7 2006 12:04:54:150PM | 1060407010 | Jerry Hughes | Rajesh is happy with the shape. J-port appears to be having trouble.
Prf=2.1MW from D+E. Push forward, trying to improve RF situation, reduce injections. PCI data is coming in starting now, Liang reports. |
| Apr 7 2006 12:18:10:650PM | 1060407011 | Jerry Hughes | RF delivery remains the same. D+E good, multiple trips on J.
Radiated power similar, only no big injection. Stays in EDA H-mode the whole time. |
| Apr 7 2006 12:24:04:543PM | 1060407012 | Jerry Hughes | Tweaked YAG alignment before this shot, and improved it apparently.
J-port has a slightly better Nice Te pedestal on first H-mode. Impurity injections kill the H-mode, but it recovers, with higher radiation. |
| Apr 7 2006 12:32:06:933PM | 1060407012 | Jerry Hughes | Tweaked YAG alignment before this shot, and improved it apparently.
J-port has a slightly better Nice Te pedestal on first H-mode. Impurity injections kill the H-mode, but it recovers, with higher radiation. Rajesh now says the shape is a perfect match. Next shot: Start doing steps in RF, as much as possible. |
| Apr 7 2006 01:21:28:323PM | 1060407012 | Decent shot. Shape looks like a perfect match to the NSTX and MAST target
shapes. Teped high early ~ 600 eV but then drops later to 400 eV. Beta ped local at outer midplane ~ 0.2%. | |
| Apr 7 2006 12:39:27:043PM | 1060407013 | Jerry Hughes | RF starts out very well, 2.5MW from D+E. Good H-modes, no injections.
Steady Te,95~500--550. J-port still can't go steady . |
| Apr 7 2006 12:49:27:870PM | 1060407013 | Nice shot. Looks like neped ~ 1.8e20, teped ~ 580 eV during steady
EDA phase. I estimate beta ped ~ 0.3% locally. Shape is a perfect match to the NSTX and MAST targets in the MP. | |
| Apr 7 2006 01:08:03:480PM | 1060407014 | Amanda Hubbard | Amanda is back in control room. Shot started well, with 3.4 MW. But disrupts ~0.8 secs. Maybe I should have stayed away...
Try to repeat, without the disruption. |
| Apr 7 2006 01:24:19:510PM | 1060407014 | Teped up to 700 eV before disruption, neped 1.7e20, beta ped local ~ 0.33%.
On the right track before the impurity influx. | |
| Apr 7 2006 01:00:28:630PM | 1060407015 | Amanda Hubbard | Post-disruption fizzle. |
| Apr 7 2006 01:23:40:887PM | 1060407016 | Amanda Hubbard | Big injection at 0.87 secs. Disrupts 0.93 s.
3.3 MW total power. Before injection, Te95 717 eV, ne95 1.7e20m-3., pe95 9.8e22 (very close to pressure on 1030612013, one of our better 600 kA H-modes) |
| Apr 7 2006 02:00:39:207PM | 1060407017 | Teped up to ~600 eV, neped 1.7e20, beta ped local ~ 0.3%. Nice shot. | |
| Apr 7 2006 01:52:14:520PM | 1060407018 | Amanda Hubbard | Tried going back to shape of shot 12. Big injection at 0.85 seconds, in low (2.7 MW) power part of the RF pulse. H-modes and RF went south from there.
So, tentatively conclude that the shape is not the main issue. Go back to NSTX shape for shot 19, shorten RF pulse and try to raise power. |
| May 18 2006 04:20:11:783PM | 1060407019 | Amanda Hubbard | Similar. RF up to 3.2 MW, But, rather large injection.
Short H-mode, 124 kJ, Te8 600 eV, Te95~700 eV, pe95~ 8e22, ne95 1.7e20. |
| Apr 7 2006 02:19:49:083PM | 1060407020 | Teped up to ~650 eV, neped 1.8e20, beta ped local ~ 0.33%, rhostar~.0045,
nustare=0.8. | |
| Apr 7 2006 02:21:41:070PM | 1060407021 | Very similar pedestal parameters to the last shot. | |
| Apr 7 2006 02:29:13:120PM | 1060407021 | Amanda Hubbard | Used less power from D more from others.
Better - later injection and it is apparently not Moly but Iron. Prf=3.1 MW, got about the same pedestal parameters. Pe_95~1..1e23 Next shot, raise target nel a little. |
| Apr 7 2006 02:35:06:133PM | 1060407022 | Amanda Hubbard | Raised target nel. Caused RF mismatch, only got 0.75 MW (from J-port).
L-mode. Retune, retry. |
| Apr 7 2006 02:44:58:590PM | 1060407023 | Amanda Hubbard | Fizzle |
| Apr 7 2006 03:07:55:850PM | 1060407024 | Amanda Hubbard |
H-Mode. Target 9e19 m-3. Surprisingly, H-mode density not much increased. Nel 1.5e20 m-2, ne ~1.8e20 m-3. pe95 0.86e 23 Only got 2.1 MW. Retune J. |
| Apr 7 2006 03:51:16:053PM | 1060407024 | Teped ~ 500 eV, neped ~ 1.7e20. OK | |
| Apr 7 2006 03:51:45:460PM | 1060407025 | Very similar to last shot. | |
| Apr 7 2006 03:51:50:083PM | 1060407025 | Amanda Hubbard | Better. 2.5-3.5 MW, some trips. pe95~9e22
Retune. |
| May 18 2006 04:23:59:580PM | 1060407026 | Amanda Hubbard | RF 3.3 MW, farily clean. Pe_95 ~1.05e23, ne951.7e20, Te95 ~611 eV |
| Apr 7 2006 03:47:38:867PM | 1060407027 | Amanda Hubbard | Tried reducing Bt to 5.0 T (off-axis heating). But, Peped dropped to 8e22, not a win in beta_tor.
Next, try going back to 5.4 T, reduce Ip to 600 kA - see if this gets into ELMy regime any easier. Target 7e19 m-2. |
| Apr 7 2006 04:22:04:187PM | 1060407028 | Amanda Hubbard |
Try reducing Ip to 600 kA. q95=6. Still EDA. Pe reduced to 8.2e22; not a net gain. |
| Apr 7 2006 04:19:39:463PM | 1060407029 | Amanda Hubbard | Go back to 700 kA, 7e19, bu with Argon off.
3.1 MW, similar to previous shots - including the Injection. Next: up to 800 kA. |
| Apr 7 2006 04:50:59:443PM | 1060407032 | Te95 approached 700 ev, n95~1.9-2e20, highest pedestal at 95% all day. | |
| Apr 7 2006 05:07:01:620PM | 1060407033 | Te95 approached 650 ev, n95~1.9-2e20; decent shot. | |
| Physics Operator Comments | |||
| Apr 7 2006 09:41:07:310AM | 1060407001 | Earl Marmar | First part of the run will be boronization recovery, bringing the RF up to ~3 MW.
load from 1060405024 decrease prefill puff to 16 msec nl_04 target to 0.8e20 dud fields look ok; B_z might be a bit too negative |
| Apr 7 2006 10:04:17:840AM | 1060407002 | Earl Marmar | prefill puff to 20 msec
EF4 10 A less negative (now -1335 A at t=0) plasma startup bounced no nl_04 data for this shot |
| Apr 7 2006 10:13:06:213AM | 1060407003 | Earl Marmar | enable argon (40 msec puff, starting at .3 seconds)
LPI enabled plasma startup better 2 MW (D+E), 149 kJ |
| Apr 7 2006 10:25:47:247AM | 1060407004 | Earl Marmar | no pcs changes
plasma fringe jump on the interferometer around .28; does not appear to have affected the feedback disruption at 0.7 s (after a big jump in radiated power) |
| Apr 7 2006 10:42:34:950AM | 1060407005 | Earl Marmar | reduce prefill puff by 1 msec (now 19 msec)
plasma disrupt at 400 kA in rampdown (Li pellet) C II signal is up (disruption on shot 4) |
| Apr 7 2006 10:53:44:497AM | 1060407006 | Earl Marmar | no pcs changes
plasma startup still looks ok disrupt in rampdown (500 kA), Li pellet |
| Apr 7 2006 11:11:47:810AM | 1060407007 | Earl Marmar | no pcs changes
plasma density is not reaching target before RF |
| Apr 7 2006 01:04:54:870PM | 1060407008 | Earl Marmar | raise nl_04 target to 9e19
plasma |
| Apr 7 2006 11:35:23:650AM | 1060407009 | Steve Wolfe | SHot#9: Earl has lowered the current to 730ka and the density to 7e19, to start Amanda/Rajesh's shot setup. He and Amanda are off to their conference call, and I'll physop for the next hour or so. |
| Apr 7 2006 11:42:12:200AM | 1060407009 | Steve Wolfe | SHot#9: plasma, 700kA, nl04=8e19 q=5.5 Two h-modes, still injections, rf on and off. Doutl may be a little high? around .55 kappa a little low around 1.67 |
| Apr 7 2006 11:53:47:463AM | 1060407010 | Steve Wolfe | Shot#10: No shape change, let RF try to get better matching Result: plasma, still one H->L at .85sec, target nl04=.77e20 kappa~1.7, du=.32, dl=.54, q=5.5; Rajesh is looking at shape overlay, J is having trouble, D&E looking ok, averaging around 2MW |
| Apr 7 2006 12:07:53:840PM | 1060407011 | Steve Wolfe | Shot#11: Repeat plasma, stays eda'ish this time. Looked like some light around the D antenna, but it runs clean. Injection at .95sec raises prad, drops Wmhd, which peaks at 114kJ. J-port still very unhappy. E-port is clean at 1MW, but the RF_POWER_NET trace isn't seeing it, so it reads low by 1MW. |
| Apr 7 2006 12:25:27:853PM | 1060407012 | Steve Wolfe | Shot#12: RXL from -.005 to +.005 to get lower delta_l (per Rajesh). Mozilla blew away in logbook for second time today plasma. Got delta_l=.48, as requested. Injection and H->L at .96seconds J a little better, RF around 3MW |
| Apr 7 2006 12:35:03:450PM | 1060407013 | Steve Wolfe | Shot#13: Mozilla Firefox blew away again. Now using IDL logbook! Repeat with RF taking a second step to higher power later in shot; hoping the injections cooperate at this level. plasma, H-mode looks steadier, Neuts/Hards around 1e13, slightly lower than last shot. RF at 2.5MW, steady to 1.0sec from D&E, J faulting late. |
| Apr 7 2006 12:48:21:307PM | 1060407014 | Steve Wolfe | Shot#14: Repeat, raise power. Early disruption. .85sec. It was on it's way to being a winner, too! Big injection, presumably Moly. RF was good at 3.3MW or so, while the plasma lasts. Next: Try again |
| Apr 7 2006 01:22:00:713PM | 1060407016 | Earl Marmar | I'm taking over from Steve Wolfe as physop.
no pcs changes plasma hesitation on startup disrupt just before 1 sec, during RF (~3 MW) |
| Apr 7 2006 01:37:10:660PM | 1060407017 | Earl Marmar | reduce B_R offset by .5 mT (now -.0005)
plasma survived (power was slightly lower) |
| Apr 7 2006 01:47:30:073PM | 1060407018 | Earl Marmar | RXL back to program from shot 11 (increase lower triangularity)
plasma EDA H-mode killed by large increase in Prad |
| Apr 7 2006 02:06:25:707PM | 1060407018 | Earl Marmar | RXL back to program from shot 11 (increase lower triangularity) |
| Apr 7 2006 02:06:25:893PM | 1060407018 | Earl Marmar | RXL back to program from shot 11 (increase lower triangularity) |
| Apr 7 2006 02:06:21:317PM | 1060407019 | Earl Marmar | back to the decreased lower triangularity (as on shot 17)
plasma |
| Apr 7 2006 02:06:39:020PM | 1060407020 | Earl Marmar | no pcs changes
plasma |
| Apr 7 2006 02:27:50:587PM | 1060407021 | Earl Marmar | no pcs changes
plasma |
| Apr 7 2006 02:37:10:950PM | 1060407022 | Earl Marmar | raise nl_04 target to 9e19
plasma RF unhappy with increased density (D and E mismatched) |
| Apr 7 2006 06:17:55:513PM | 1060407023 | Earl Marmar | no pcs changes
fizzle B_z may be creeping up a bit |
| Apr 7 2006 06:18:28:047PM | 1060407024 | Earl Marmar | reduce prefill puff by 1 msec (now 18 msec)
EF4 10 A more negative (now -1345 A) plasma |
| Apr 7 2006 03:17:26:863PM | 1060407025 | Earl Marmar | no pcs changes
plasma j-port struggling |
| Apr 7 2006 03:48:02:960PM | 1060407026 | Earl Marmar | no pcs changes
plasma |
| Apr 7 2006 03:48:31:473PM | 1060407027 | Earl Marmar | I_TF to -139 kA
plasma |
| Apr 7 2006 03:55:10:397PM | 1060407028 | Earl Marmar | I_TF back to -150 kA
I_p to 600 kA nl_04 target to 6e19 plasma |
| Apr 7 2006 04:11:02:160PM | 1060407029 | Earl Marmar | I_p to 700 kA
disable argon puff (B side lower) plasma |
| Apr 7 2006 04:18:41:837PM | 1060407030 | Earl Marmar | 800 kA
argon still off fizzle |
| Apr 7 2006 04:44:58:130PM | 1060407031 | Earl Marmar | EF4 5 A more negative (now -1350 A)
plasma |
| Apr 7 2006 04:45:12:287PM | 1060407032 | Earl Marmar | EF4 to -1345 A
I_p to 700 kA plasma |
| Apr 7 2006 06:14:46:123PM | 1060407033 | Earl Marmar | nl_04 target to 6e19
plasma |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:37:13:480AM | Plasma | Ok | |
| 2 | 09:50:26:277AM | Plasma | Ok | |
| 3 | 10:03:45:247AM | Plasma | Ok | |
| 4 | 10:18:01:527AM | Plasma | Ok | |
| 5 | 10:32:13:590AM | Plasma | Ok | |
| 6 | 10:46:45:963AM | Plasma | Ok | |
| 7 | 11:03:10:527AM | Plasma | Ok | |
| 8 | 11:22:04:307AM | Plasma | Ok | |
| 9 | 11:34:29:980AM | Plasma | Ok | |
| 10 | 11:46:59:027AM | Plasma | Ok | |
| 11 | 11:59:49:213AM | Plasma | Ok | |
| 12 | 12:16:21:903PM | Plasma | Ok | |
| 13 | 12:29:44:370PM | Plasma | Ok | |
| 14 | 12:42:44:730PM | Plasma | Ok | |
| 15 | 12:55:09:440PM | Plasma | Ok | |
| 16 | 01:07:45:290PM | Plasma | Ok | |
| 17 | 01:23:08:527PM | Plasma | Ok | |
| 18 | 01:36:54:550PM | Plasma | Ok | |
| 19 | 01:50:16:330PM | Plasma | Ok | |
| 20 | 02:02:44:363PM | Plasma | Ok | |
| 21 | 02:15:36:693PM | Plasma | Ok | |
| 22 | 02:28:07:667PM | Plasma | Ok | |
| 23 | 02:40:43:997PM | Plasma | Ok | |
| 24 | 02:53:19:090PM | Plasma | Ok | |
| 25 | 03:06:06:867PM | Plasma | Ok | |
| 26 | 03:18:45:880PM | Plasma | Ok | |
| 27 | 03:34:03:333PM | Plasma | Ok | |
| 28 | 03:49:04:600PM | Plasma | Ok | |
| 29 | 04:03:16:800PM | Plasma | Ok | |
| 30 | 04:15:58:990PM | Plasma | Ok | |
| 31 | 04:28:47:987PM | Plasma | Ok | |
| 32 | 04:41:55:177PM | Plasma | Ok | |
| 33 | 04:56:39:040PM | Plasma | Ok | |