| Miniproposals | ||||||||||
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| Operators | |
| Session leader(s): | Brian Labombard |
| Physics operator(s): | Robert Granetz |
| Engineering operator(s): | Bill Cochran,Sam Pierson,Bill Byford |
| Engineering Operator Run Comment |
| MP#409 SOL Phase Space - reversed field |
| Session Leader Plans |
| Entered: May 17 2006 09:00:27:620PM |
| Author: Brian Labombard |
| Run Plan for 1060518 MP#409 "SOL Phase space studies" - Reversed Field Goal Continue the SOL 'phase space' mapping studies at 0.8MA and 5.4Tesla, but with reversed plasma current and field direction. Run Preparation Tasks - since we managed to get a start on this MP yesterday, the probes and optical diagnostics are already ready to go (see plan for 1060517) - Set timing on fastdiode digitizers to 0.1 s after the A-B limiter NINJA puff timing Plan Begin with shot#1060517033, but running in LSN (segment#2 on) and with inner gap set 1mm smaller (for ISP target improvement) Also, set NL04=0.6. This is a 0.8MA, 5.4T REVERSED field LSN discharge. ASP, ISP programmed to scan at 0.65, 0.85, 1.05 seconds NINJA gas puff for GPI and boron V spectroscopy entering plasma at 1.1s Set NINJA for D2 puff at A-B limiter and B016-001. Plenum pressure of 10 PSI. Shots 1,2,3 LSN, NL04 = 0.6, optimize probe targeting 4,5,6 USN, NL04 = 0.6, optimize probe targeting 7,8 USN, NL04 = 0.4 9,10 LSN, NL04 = 0.4 11,12 LSN, NL04 = 0.8 13,14 USN, NL04 = 0.8 15,16 USN, NL04 = 1.0 17,18 LSN, NL04 = 1.0 19,20 LSN, NL04 = 1.2 21,22 USN, NL04 = 1.2 23,24 USN, NL04 = 1.4 25,26 LSN, NL04 = 1.4 Allow for repeated attempts of these shots. Shot total is ~30 |
| Physics Operators Plans |
| Entered: May 17 2006 05:01:49:680PM |
| Author: Robert Granetz |
Engineering setup for Thursday 18 May 2006
MP#409 SOL Phase Space - reversed field
Session leaders: B. Labombard
Physics operator: R. Granetz
Overnight ECDC in deuterium; bake at 60 C.
The run will start at 09:00 and end at 17:00.
Power systems as on 1060517033.
A-coil configuration: normal [-Dtop +Dbot +Jtop -Jbot] and enabled.
Gas Setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar + 2 psi Ne Hybrid DISABLED (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, Z-bolo shutters
Torvac setup: Gate valves open
Key diagnostics: Gas puff imaging, scanning probes, HIREX rotation, edge
Thomson, and...that's good enough.
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ICRF Setup: no RF at any time.
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Run plan: Load shot 1060517033, but turn on segment 2 (LSN) instead of
segment 3 (USN). Also reduce inner wall gap by 1 mm, keeping the
outer gap unchanged. Toggle lower null and upper null
discharges, raising nl_04 after each pair of discharges (with
some repetition, of course). See Brian's session plan for more
info.
|
| Session Leader Summaries |
| Entered: May 18 2006 10:05:45:190PM |
| Author: Brian Labombard |
| Run Summary for 1060518 MP#409 "SOL Phase space studies" - Reversed field This was a rough day. We started off ok, with shot#1 being a re-run of a LSN discharge developed during the 1060517 setup run. But, immediately on shot#2, we managed to overheat the A-port probe, resulting in a short to the EAST electrode. For some reason, the outer gap seemed to change relative to shot#1 (more on this later). After trying to unshort the probe by applying high-current bias, we pushed on with obtaining a matched USN discharge. The density proved to be difficult to control with the plasma running much lower (about 0.2 in NL04 lower than programmed). By shot#14, things were looking better. The EAST probe unshorted and we got some control on the density (yet a bit high). But immediately after that on shot#15 the left gap jumped by 2mm, hitting the inner wall probe hard. It became apparent (after fizzles plus F11 flux loop warnings) that the F11 flux loop was not reliable. Bob found that the loop is shorted to the machine, which could be a problem if there are muliple shorts. Shot#19 went, but it became very clear that F11 was not reliable, as a 'jog' in the EFIT derived shape quantities was seen around 0.95s with EFIT reporting bad fits at and beyond this time. The run was ended for Steve and Bob to come up with a work-around. We did manage to collect a few data points. Plasma flows on the high-field side were found to persistently flow towards the inner divertor strike point location, as they do in forward field. I think we might have a couple of shots with info on flows on the low-field side for LSN versus USN. ___________________________________________________________________________________ Quick shot log ISP pulse duration set to 22 ms. MP#409 - reversed field 01- LSN, Ip=0.8MA, NL04=0.78, ASP(+8) Vf mode, ISP-good Vf mode 02- LSN, Ip=0.8MA, NL04=0.6, ASP(+10)- too deep!, ISP-good 03-04 no power cycle tests 05- LSN, Ip=0.8MA, NL04=0.58, ASP(+8) good EAST shorted, ISP-good 60eV disrupted at 0.6s 06 - fizzle 07- LSN, Ip=0.8MA, NL04=0.55-0.46, ASP(+8) good EAST shorted, ISP 08- LSN, Ip=0.8MA, NL04=0.5, ASP(+8) good EAST floating, ISP-good 09- USN, Ip=0.8MA, NL04=0.3, ASP(+9) EAST floating, ISP 10- USN, Ip=0.8MA, NL04=0.3, ASP(+10) good EAST floating, ISP 11 - fizzle 12- USN, Ip=0.8MA, NL04=0.5-0.3, ASP(+10) EAST floating, ISP 13 - fizzle 14- USN, Ip=0.8MA, NL04=0.6-0.5, ASP(+10) EAST sweep-> OK on third scan!, ISP 15- USN, Ip=0.8MA, NL04=0.85-0.75, ASP(+10) could be deeper, ISP 2mm too far! 16- fizzle 17- fizzle 18- fizzle 19- USN - no probes scanning end of run |
| Physics Operator Summaries |
| Entered: May 18 2006 04:03:02:593PM |
| Author: Robert Granetz |
Run summary for Thursday 18 May 2006:
MP#409 SOL Phase Space - reversed field
Session leader: B. Labombard
Physics operator: R. Granetz
This reversed-field run started out okay, but we eventually figured out
that sometime after shot 7, flux loop F11 was failing in a subtle,
intermittent, and unpredictable fashion. This resulted in a number of
fizzles when F11 failed before t=0, and incorrect boundary position (1-2
mm) when it failed during the plasma discharge. So we had to stop the run
after shot 19 and begin working on a software fix to substitute a linear
combination of nearby flux measurements. Not sure about the status of
tomorrow's run.
Scorecard: 11 plasmas
0 duds
6 fizzles
0 gas system tests
0 TF scanner tests
0 power supply test (TF-only)
2 no power MDS shot cycles
--------------
Total: 19 shot cycles
|
| Session Leader Comments | |||
| May 18 2006 09:11:15:080AM | 1060518001 | Brian Labombard | Shot 01 LSN, NL04=0.78 Ip=0.8, Bt=5.4 REVERSED Plasma doesn't swallow the gas puff until 0.6 s ASP, ISP scanning at 0.65, 0.85, 1.05s ASP - could be deeper - floating mode ISP - good - floating mode Next: Repeat with NL04 =0.6 |
| May 18 2006 09:27:41:343AM | 1060518002 | Brian Labombard | Shot 02 LSN, NL04=0.6 Ip=0.8, Bt=5.4 REVERSED ASP, ISP scanning at 0.65, 0.85, 1.05s ASP - too deep! ISP - good Next: Repeat with ASP pulled back. |
| May 18 2006 11:06:32:953AM | 1060518007 | Brian Labombard | Shot 07 LSN, NL04=0.5 Ip=0.8, Bt=5.4 REVERSED ASP, ISP scanning at 0.65, 0.85, 1.05s ASP - good, EAST still shorted ISP - could be deeper Next: Repeat with EAST floating |
| May 18 2006 11:07:03:627AM | 1060518008 | Brian Labombard | Shot 08 LSN, NL04=0.5 Ip=0.8, Bt=5.4 REVERSED ASP, ISP scanning at 0.65, 0.85, 1.05s ASP - good, EAST floating ISP - good Next: go to USN, same density |
| May 18 2006 11:40:07:673AM | 1060518009 | Brian Labombard | Shot 09 USN, NL04=0.3 Ip=0.8, Bt=5.4 REVERSED ASP, ISP scanning at 0.65, 0.85, 1.05s ASP - could be deeper, EAST floating ISP - good Next: try for NL04=0.5 |
| May 18 2006 11:40:44:627AM | 1060518010 | Brian Labombard | Shot 10 USN, NL04=0.3 Ip=0.8, Bt=5.4 REVERSED ASP, ISP scanning at 0.65, 0.85, 1.05s ASP - ok, EAST floating ISP - good Next: try again for NL04=0.5 |
| May 18 2006 12:11:15:063PM | 1060518012 | Brian Labombard | Shot 12 USN, NL04=0.5-0.3 Ip=0.8, Bt=5.4 REVERSED ASP, ISP scanning at 0.65, 0.85, 1.05s ASP - ok, EAST floating ISP - good Next: go to NL04=0.7 |
| May 18 2006 12:39:27:047PM | 1060518014 | Brian Labombard | Shot 14 USN, NL04=0.6-0.5 Ip=0.8, Bt=5.4 REVERSED ASP, ISP scanning at 0.65, 0.85, 1.05s ASP - ok, EAST sweep => Unshorts on third scan! ISP - good Next: try again for NL04=0.7 |
| May 18 2006 12:58:00:907PM | 1060518015 | Brian Labombard | Shot 15 USN, NL04=0.85-0.75 Ip=0.8, Bt=5.4 REVERSED ASP, ISP scanning at 0.65, 0.85, 1.05s ASP - could be deeper. EAST is ok. ISP - 2mm over-inserted Next: Adjust inner gap, lower NL04 slightly, run again. |
| Physics Operator Comments | |||
| May 18 2006 05:18:58:653AM | Robert Granetz | Loaded shot 1060517033 (all segments). Switched on segment 2 (LSN) instead of segment 3 (USN). Reduced CLEARIN by 1 mm and RCUR by 0.5 mm. | |
| May 18 2006 09:10:34:593AM | 1060518001 | Robert Granetz | Shot 01 -- Plasma. Good shot. Density took a while to get to its programmed value. Not sure why. Next shot: Reduce nl_04 to 0.8e20 m-2. Tweak scanning probe settings. |
| May 18 2006 09:33:20:127AM | 1060518002 | Robert Granetz | Shot 02 -- Plasma. Good shot. 0.8 MA, 5.45 T, nl_04=0.6e20 m-2. Next shot: repeat, no DPCS changes. |
| May 18 2006 09:41:39:643AM | 1060518003 | Robert Granetz | Shot 03 -- No-power shot, due to an MDS problem with the shot cycle. Josh will work on fixing it after this shot. |
| May 18 2006 10:17:54:500AM | 1060518004 | Robert Granetz | Shot 04 -- No-power test shot. Still having MDS cycle problems. Josh is working on it. |
| May 18 2006 10:33:24:017AM | 1060518005 | Robert Granetz | Shot 05 -- Plasma. Disrupted at t=0.70 s. Big increase in radiated power starting at t=0.68, shortly after the first A-probe insertion. Are they related? Next shot: increase CLEARIN by 1 mm and RCUR by 0.5 mm (to keep outboard gap the same). Hopefully no disruption |
| May 18 2006 10:43:35:487AM | 1060518006 | Robert Granetz | Shot 06 -- Fizzle. No doubt due to the disruption. Next shot: reduce pre-fill puff by 2 ms. |
| May 18 2006 10:59:15:830AM | 1060518007 | Robert Granetz | Shot 07 -- Plasma. Good shot. Next shot: decrease CLEARIN by 1 mm and RCUR by 0.5 mm (reload these wires from shot 05) |
| May 18 2006 11:07:07:297AM | 1060518008 | Robert Granetz | Shot 08 -- Plasma. Good shot. Lower null (same as all previous shots today). Next shot: switch to upper null by turning on segment 3 and turning off segment 2. |
| May 18 2006 11:29:38:080AM | 1060518009 | Robert Granetz | Shot 09 -- Plasma. Just made it into rampdown before disrupting. Density was a lot lower than we requested. Might have been a locked mode for much of the discharge. Next shot: add a little more pre-programmed gas in segment 3. |
| May 18 2006 11:41:11:297AM | 1060518010 | Robert Granetz | Shot 10 -- Plasma. Disrupted at t=1.04 s. Another very low density shot with a locked mode during most of the discharge. These USN shots should have been repeats of the shots from late in yesterday's run, but clearly the density is not reproducible. Next shot: increase preprogrammed gas puff substantially in segment 3. |
| May 18 2006 11:52:10:017AM | 1060518011 | Robert Granetz | Shot 11 -- Fizzle. Fields and pressure look fine. Next shot: take another 1 ms off of PG4 in seg 1. |
| May 18 2006 12:06:54:297PM | 1060518012 | Robert Granetz | Shot 12 -- Plasma. Good shot. Full length. Upper null. Next shot: raise nl_04 to 0.75e20 m-2. |
| May 18 2006 12:22:28:203PM | 1060518013 | Robert Granetz | Shot 13 -- Fizzle. Next shot: subtract another 1 ms from pre-fill, just to say I did something. |
| May 18 2006 12:38:41:907PM | 1060518014 | Robert Granetz | Shot 14 -- Plasma. Good shot, but the density is still less than we want. Next shot: set nl_04 to 1.0e20 m-2 (in seg 3). |
| May 18 2006 12:59:05:593PM | 1060518015 | Robert Granetz | Shot 15 -- Plasma. Good shot. nl_04 is about 0.8e20 m-2. Next shot: tweak nl_04 down to 0.95e20 m-2. Increase CLEARIN by 2 mm and RCUR by 1 mm. |
| May 18 2006 01:16:30:703PM | 1060518016 | Robert Granetz | Shot 16 -- Fizzle. Bz0 dropped by several mT. Next shot: Raise IC_EF4 by 15 amps. |
| May 18 2006 01:23:58:890PM | 1060518017 | Robert Granetz | Shot 17 -- Fizzle. Bz0 is still very low. Next shot: add 30 amps to IC_EF4. |
| May 18 2006 02:00:17:563PM | 1060518018 | Robert Granetz | Shot 18 -- Fizzle. F11 has a large error. It had errors reported on several previous shots today as well. I went into the cell after the shot and found that F11 is shorted to the vessel, which isn't necessarily a show stopper unless there's a 2nd intermittent short, which there may be. Next shot: undo the 30 amp changes to IC_EF4 and see if the flux has fixed itself. |
| May 18 2006 02:10:38:610PM | 1060518019 | Robert Granetz | Shot 19 -- Plasma, but F11 goes bad around t=1 s, as seen from the EFIT errors. At the time of the error there isn't anything obvious on the F11 signal. F11 is not an easy measurement to mock up from its neighbors, but we're going to have to get around this somehow. |
| May 18 2006 03:27:56:017PM | 1060518019 | Robert Granetz | We have confirmed that flux loop F11 is failing in an intermittent and unpredictable fashion. We therefore have to zero it out in all the relevant software and substitute a suitable linear combination of other flux loops. [F12 - (F16 - F17) gives a very good approximation throughout an entire pulse.] However, it will take several hours to install these patches...maybe more since the last time we had to do this was six years ago and we're rusty. So the rest of today's run is in jeopardy, and we might need a late start tomorrow. |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 08:57:53:063AM | Plasma | Ok | |
| 2 | 09:13:11:297AM | Plasma | Ok | |
| 3 | 09:34:40:767AM | Plasma | Bad | Shot Cycle Problem |
| 4 | 09:54:40:690AM | Plasma | Bad | Shot cycle trouble |
| 5 | 10:17:54:923AM | Plasma | Ok | |
| 6 | 10:34:44:720AM | Plasma | Ok | |
| 7 | 10:47:24:737AM | Plasma | Ok | |
| 8 | 11:00:32:737AM | Plasma | Ok | |
| 9 | 11:17:28:940AM | Plasma | Ok | |
| 10 | 11:33:35:987AM | Plasma | Ok | |
| 11 | 11:45:59:533AM | Plasma | Ok | |
| 12 | 11:58:24:970AM | Plasma | Ok | |
| 13 | 12:14:39:860PM | Plasma | Ok | |
| 14 | 12:27:21:487PM | Plasma | Ok | |
| 15 | 12:46:43:890PM | Plasma | Ok | |
| 16 | 01:03:34:860PM | Plasma | Ok | |
| 17 | 01:17:30:737PM | Plasma | Ok | |
| 18 | 01:30:18:390PM | Plasma | Ok | |
| 19 | 02:01:05:593PM | Plasma | Ok | |