| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Chuck Kessel |
| Physics operator(s): | Ron Parker |
| Engineering operator(s): | Andy Pfeiffer,Bill Parkin,Bill Byford |
| Engineering Operator Run Comment |
| MP#492: Lower Ip Advanced Scenarios SL: Kessel, Hubbard PO: Parker |
| Session Leader Plans |
| Entered: Jul 11 2007 05:30:04:547PM |
| Author: Chuck Kessel |
| 1) repeat 1070711020 with boronized machine
2) repeat 1070711021 with boronized machine 3) 500 ms rampup to 450 kA ohmic discharge for setup 4) 500 ms rampup to 450 kA a) 1.0 MW ICRF at 500 ms b) 1.0 MW ICRF at 200 ms c) 1.0 MW ICRF at 200 ms, 2.0 MW at 400 ms d) 2.0 MW at 200 ms 5) 500 ms rampup to 450 kA a) 0.4 MW LH at 200 ms 6) 500 ms rampup to 450 kA a) 1.0 MW ICRF at 200 ms and 0.4 MW LH at 200 ms b) 2.0 MW ICRF at 200 ms and 0.4 MW LH at 200 ms ---> Use long ICRF and LH pulses ---> consider higher density to get more sustainable H-modes 7) repeat above at 1000 ms ramp to 450 kA |
| Physics Operators Plans |
| Entered: Jul 11 2007 03:23:06:793PM |
| Author: Ron Parker |
| Physop Plan and Engineering setup for Thursday, July 12, 2007
MP#492: Lower Ip Advanced Scenarios SL: Kessel, Hubbard PO: Parker Overnight boronization (ending at 05:00) using the "new standard parameters": sweep 75/80/85 (min/dwell/max) dwell/period 20/120 Use EF4 vertical field, 200 Amps Following boronization: ECDC for two hours Start 06:00, finish 8:00 He4: 5e-5 Torr sweep 44/45/90 (min/dwell/max) dwell/period 20/120 Engineering Setup ------------------ Engineering setup: ------------------- Power systems as on 1070711016 A-coil configuration standard (+Dtop -Dbot -Jtop +Jbot) enabled start time 0.2sec Gas setup: fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar Hybrid Enabled (PG1) leave B-side upper as is Hybrid DISABLED (PG2) fill B-main (C-side) with 40 psi D2 Hybrid enabled (PG3) fill NINJA with 10 psi D2 Enabled Enable the following gate valves and shutters, assuming no vacuum problems: ECE, VUV, DNB, Z-bolo shutters Torvac setup: Gate valves open ICRF: In RUN-ON by 08:00 (#1,2, and 4) LH: Ready for use Physop plan: Continue plan outlined in PO Plan for 1070711, beginning with shots developed toward end of that run. |
| Session Leader Summaries |
| Entered: Jul 13 2007 09:47:10:840AM |
| Author: Chuck Kessel |
| MP492 Lower Ip Plasmas with ICRF and LH heating/CD
The run day began by trying to reproduce 1070711020 and 1070711021 from the previous day (Ip = 600 kA), with freshly boronized walls to see if the H-mode onset or duration was affected. With a little trouble at first we got shot 003, which was the 500 ms rampup, to go thru, but then had CAMAC problems. We lost a lot of time for this fix (thanks to Stillerman and Wolfe for Herculean efforts), and resumed with shot 006, which had ICRF but no LH, at about noon. We were seeing high 2pi Bolo readings most of the day which seemed strange for L-mode after a recent boronization. Shot 007 went thru with both 2.0 MW of ICRF and 0.4 MW of LH. We moved on to the 1000 ms ramp (up to 600 kA) and got a good shot with both ICRF and LH. We tried to reduce the density peak between 200 and 500 ms that appears on the LH probes by enlarging the outer gap, and this appeared to work. The issue of EFIT outer gap prediction versus the real distance came up. Shot 009 was similar with the LH power dropped slightly to avoid trips (arcs). We tried higher density on the next shot to test the idea that we may be at low enough density that H-modes are hard to make and/or sustain. Sure enough we entered an H-mode much earlier, but got a disruption. We were not able to repeat this discharge, and went on to produce an ohmic reference for 1000 ms ramp to 600 kA in shot 014. With shot 015 we moved on to the 500 ms ramp to 450 kA, and produced a good shot right away. Shot 016 was also an ohmic reference with a little tweeking of the Ip ramp. Shot 017 had 1.0 MW of ICRF on at 200 ms, 018 had 1.0 MW ICRF at 200 and 2.0 MW at 400 ms (producing one of our longest H-mode periods), but 019 had no H-mode until the very end in spite of 2 MW of ICRF on at 200 ms. Then we had commutator fuse and gate drive board problems that took some time to recover from. We had only 3 shots left at the end of the run day and they all died very early at roughly 60 ms. Overall it was a rough day with 2 long delays. We did not get to injecting the LH into the 450 kA discharges, or inject the combination of 2 MW ICRF and 0.4 MW of LH. Our problems were unrelated to the heating\/CD sources, so that is encouraging. There were no apparent problems making the 450 kA discharges or injecting power into them. We were not able to get the systematic scans we were after, like we did on the previous day at 600 kA. The H-mode behavior seemed similar to the 600 kA discharges. There was high frequency MHD (TAE or related) in these discharges when the plasma went into H-mode. It is not clear whats going on, but the H-mode transition can change the q evolution fairly strongly, and it would be strongest at the lower Ip. We were starting to look at how the Ip trajectory is behaving after the crowbar, since it usually lulls or even sags, and it seems that more work is necessary to optimize either the requested Ip trace or the gain and crowbar timing. In these discharges this phase is not destructive to the discharge and can be passed thru fairly reliably, but it is probably leading to the higher li at very early times. This is important if are to move the divert/heat/H-mode time as close to the crowbar time as possible in future work. Shot 003 600 kA in 500 ms, ICRF 2 MW Shot 006 600 kA in 500 ms, ICRF 2 MW Shot 007 600 kA in 500 ms, ICRF 2 MW and LH 0.4 MW Shot 008,009 600 kA in 1000 ms, ICRF 2 MW and LH 0.4 MW Shot 010 600 kA in 1000 ms, ICRF 2 MW and LH 0.4 MW, higher n Shot 014 600 kA in 1000 ms, ohmic ref Shot 015,016 450 kA in 500 ms, ohmic ref Shot 017 450 kA in 500 ms, ICRF 1 MW Shot 018 450 kA in 500 ms, ICRF 1 MW then 2 MW Shot 019 450 kA in 500 ms, ICRF 2 MW |
| Physics Operator Summaries |
| Entered: Jul 12 2007 05:36:42:247PM |
| Author: Ron Parker |
| The run was devoted to producing discharges with slow Ip ramps together with combination of LHCD and ICRH heating to delay sawteeth. Shots 8 and 9 were good representatives of successful shots, with current ramping to 600 kA over 1 sec.
LHCD power was ~ 400 kW while ICRF power was ~ 2 MW. In both shots, H Modes developed late in the shot. Later in the run, the maximum current was reduced to 450 kA with a 0.5 s ramp. ICRH was successfully applied to the ramp phase with ~ 1 MW in shot 17 and 2 MW in shots 18 and 19. Unfortunately, 3 fuses blew in OH1 during shot 19. After a 40 minute delay, shots were resumed but the remaining shots disrupted early near cross-over. It was noticed that Ip programming in segment 1 was actually trying to decrease Ip due to the timing of the Ip feedback. This was remedied for shots 21 and the last shot, namely 22, but both shots still disrupted near crossover. Thus we were unsuccfessful in applying LHCD to the early phase of the 450 kA rampup shot and this part of the MP will need to be rescheduled. Overall, a bit frustrating today -- a 2 hour delay due to a Camac problem and the above mentioned delay due to a loss of fuses in OH 1. There were 21 attempts at plasmas, with 2 fizzles and 5 disruptions, 1 no power shot and 1 shot with no EF4. The remaining 12 shots ran well and many produced useful data. The relatively large number of disruptions were mainly associated with developing the unusual startup mode and was not due to faulty machine condiitons. |
| Session Leader Comments |
| Physics Operator Comments | |||
| Jul 12 2007 09:08:54:747AM | 1070712001 | Ron Parker | First shot was a dud, big Bz error field. EF4 didn't turn on.
Try shot (reproduce shot 1070711020) again. |
| Jul 12 2007 09:12:50:873AM | 1070712001 | Ron Parker | Power room entry for ICRF. |
| Jul 12 2007 09:20:57:083AM | 1070712001 | Ron Parker | Waiting for computer to reboot. Plasma attempt coming up. |
| Jul 12 2007 09:28:35:900AM | 1070712002 | Ron Parker | Shot 2 disrupted at 150 ms, 300 kA. Poor startup. |
| Jul 12 2007 09:39:25:763AM | 1070712002 | Ron Parker | For shot 3, we've added a point on current program at 75 ms, 250 kA. |
| Jul 12 2007 09:51:06:897AM | 1070712003 | Ron Parker | Shot 3 ran, ICRF was there but the LH was not.
Upper grill density low, move RXU out to .03 |
| Jul 12 2007 10:07:54:270AM | 1070712004 | Ron Parker | Nothing went! No TF, PF etc. ??? Camac failed.
While Josh, Tom and Steve look into the Camac problem, we'll have cell access to open MSE shutter. |
| Jul 12 2007 11:40:36:080AM | 1070712004 | Ron Parker | We are ready for a no-power cycle --coming up. If OK, we'll start with plasmas again. |
| Jul 12 2007 12:07:51:263PM | 1070712005 | Ron Parker | That was the no-power cycle. Plasma shot upcoming. |
| Jul 12 2007 01:02:21:290PM | 1070712006 | Ron Parker | Shot 6 ran well. |
| Jul 12 2007 12:27:13:637PM | 1070712007 | Ron Parker | Shot 7 ran OK, LH plus ICRF.
Next: Slower ramp |
| Jul 12 2007 01:01:35:227PM | 1070712008 | Ron Parker | Shot 8 ran well with long Ip ramp (t~ 1s). Sawteeth delayed to 0.6 s |
| Jul 12 2007 01:04:17:510PM | 1070712009 | Ron Parker | Shot 9 ran, similar to 8 but swateeth come earlier. |
| Jul 12 2007 01:20:46:520PM | 1070712010 | Ron Parker | Shot 10 ran, seems to be leaning to outside, so reduce RCUR by 2mm for next shot. |
| Jul 12 2007 01:24:27:727PM | 1070712011 | Ron Parker | Shot 11 was the traditional fizzle-after-disruption shot. |
| Jul 12 2007 01:48:02:557PM | 1070712012 | Ron Parker | Shot 12 disrupted, be prepared for fizzle on next shot.
If it goes, it will be Ohmic only. |
| Jul 12 2007 01:51:43:890PM | 1070712013 | Ron Parker | As expected, fizzle although it almost made it. Do over. |
| Jul 12 2007 02:15:49:720PM | 1070712014 | Ron Parker | Shot 14 went off well, but disrupted around 1.3 s. OH shot, BIG drop in radiation!
Reduce fill gas by 3 ms to try to avoid fizzle on next shot. |
| Jul 12 2007 03:08:54:057PM | 1070712015 | Ron Parker | Shot 15 ran nicely, 450 kA @ 0.5 s OH shot.Next: Also OH, but more gentle Ip ramp. |
| Jul 12 2007 02:37:06:143PM | 1070712016 | Ron Parker | Shot 16 ran well, again OH only. Ip = 450 kA, slow ramp. Sawtweeth start ~ 250 ms.
Next: same shot, but 1 MW RF. |
| Jul 12 2007 03:09:50:650PM | 1070712017 | Ron Parker | Shot 17 ran well, 1 MW ICRF. |
| Jul 12 2007 03:10:41:320PM | 1070712018 | Ron Parker | Shot 18 ran well, ICRF 2 MW stepped. Nice H-Mode toward end of shot. |
| Jul 12 2007 03:23:06:340PM | 1070712019 | Ron Parker | Shot 19 went off OK, H-mode only at the end of shot.
Fuse indication, need power room access to check it out. Next: 2.25 MW ICRF. |
| Jul 12 2007 03:50:45:580PM | 1070712019 | Ron Parker | Preliminary report on OH 1: Lost 3 fuses and gate drive board.
Gary estimates 45 minutes for repair. |
| Jul 12 2007 04:28:58:780PM | 1070712019 | Ron Parker | Ready for shot @ 4:30. |
| Jul 12 2007 04:45:47:077PM | 1070712020 | Ron Parker | Shot 20 disrupted. Turned out Segment 1 was trying to reduce current at 40 ms when gain came on. Next shot will have this corrected. |
| Jul 12 2007 04:48:36:843PM | 1070712021 | Ron Parker | Shot 21 disrupted, try again. |
| Jul 12 2007 04:58:41:790PM | 1070712022 | Ron Parker | Disrupted again, for reasons unknown. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 09:01:22:227AM | Plasma | Bad | EF4failed to run do to an interlock fault |
| 2 | 09:24:59:670AM | Plasma | Ok | |
| 3 | 09:38:16:387AM | Plasma | Ok | |
| 4 | 09:51:34:163AM | Plasma | Bad | (09:56:06) twf: looks like pcdaqdpcs1 crashed or was rebooted |
| 5 | 11:55:23:550AM | Test | Ok | no power shot |
| 6 | 12:06:50:387PM | Plasma | Ok | |
| 7 | 12:21:09:507PM | Plasma | Ok | |
| 8 | 12:34:54:393PM | Plasma | Ok | |
| 9 | 12:51:49:367PM | Plasma | Ok | |
| 10 | 01:06:31:197PM | Plasma | Ok | |
| 11 | 01:21:25:240PM | Plasma | Ok | |
| 12 | 01:34:37:720PM | Plasma | Ok | |
| 13 | 01:48:15:260PM | Plasma | Ok | |
| 14 | 02:01:18:343PM | Plasma | Ok | |
| 15 | 02:15:40:393PM | Plasma | Ok | |
| 16 | 02:30:39:857PM | Plasma | Ok | |
| 17 | 02:43:43:900PM | Plasma | Ok | |
| 18 | 03:00:33:990PM | Plasma | Ok | |
| 19 | 03:13:46:790PM | Plasma | Ok | |
| 20 | 04:29:57:657PM | Plasma | Ok | |
| 21 | 04:43:22:433PM | Plasma | Ok | |
| 22 | 04:56:43:160PM | Plasma | Ok | |
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