| Miniproposals | ||||||||||
|
| Operators | |
| Session leader(s): | Greg Wallace |
| Physics operator(s): | Steve Wolfe |
| Engineering operator(s): | Bill Parkin,Bill Cochran,Bill Byford |
| Engineering Operator Run Comment |
| MP551, "Penetration of Accessible LH Waves."Session Leader: G. Wallace P |
| Session Leader Plans |
| Entered: Apr 23 2008 12:25:29:730PM |
| Author: Greg Wallace |
| Session Leader Plan for 1080424
Session Leader: G. Wallace Physics Operator: S. Wolfe This run will be in support of MP551, "Penetration of Accessible LH Waves." We will be investigating the drop-off of HXR emission as the line integrated density rises above ~6e19. LH Setup: Launcher 1.0mm behind limiter, 75 and 105 degree approximate phasing, current drive direction, 600kW net power, LH on from 0.7-1.2s. Starting Shot: 1080408020 Shot Plan: 1. Bring up LH power to 600kW at 75 degree phasing with nl_04 steady at 4e19, 5.4T, 800kA. (2 shots) 2. Scan density from 3e19 (or as low as possible without locked modes) to 6e19 nl_04 between 0.7 and 1.2 seconds at 5.4 T, 800kA, 75 degrees. Cryopump and/or inner wall puffing may be required for density control. Repeat at 105 degrees. (2 shots) 3. Scan density from 5e19 to 1e20 nl_04 between 0.7 and 1.2 seconds at 5.4 T, 800kA, 75 degrees. Cryopump and/or inner wall puffing may be required for density control. Repeat at 105 degrees. (2 shots) 4. Repeat 2 and 3 at 6.2T, 800kA. (4 shots) 5. Repeat 2 and 3 at 5.0T, 800kA. (4 shots) 6. Repeat 2 and 3 at 5.4T, 500kA. (4 shots) 7. Repeat 2 and 3 at 5.4T, 1.1MA. (4 shots) 8. Repeat 2 and 3 at 5.4T, 800kA, 900kW. (4 shots) Total of 26 shots. |
| Physics Operators Plans |
| Entered: Apr 23 2008 12:46:03:510PM |
| Author: Steve Wolfe |
| -----------------
Engineering Setup ----------------- Run begins at 09:00 and ends at 17:00 Power systems as on: 1080408020 Except change C-coil start time to 0.2 sec Acoil: +Dtop -Dbot -Jtop +Jbot (standard) Hybrid Enabled Gas setup: Fill B-Top with 6 psi D2 Hybrid enabled (PG4) fill B-side lower with 1 psi Ar 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 DISABLED Enable gatevalves and shutters: ECE, VUV, DNB, Z-bolo Torvac gatevalve toggle (yes/no): NO Boronization(yes/no): no Overnight ECDC (yes/no): YES ICRF(yes/no): NO LH(yes/no): YES DNB(yes/no): yes Cryopump (yes/no): YES ready for first shot Vessel temperature: 35/35/35 ------------------------------ ECDC Parameters (if requested) ------------------------------ gas and pressure: D2 at 2e-4 Torr sweep: 44/45/103 cm scan: 20/120 s ****************************************************** Physop plan: 1. Load from 1080408020 and increase pg4 for cryopump Will use cryopump all day unless it starts causing problems, in which case we'll live without it. Adjust nl04 in seg 3 to flat 4e19 2. Program nl04 to ramp from 3e19 to 6e19 between 0.7 and 1.2sec (LH to do 2-point phase scan) 3. Program nl04 to ramp from 5e19 to 1e20 between 0.7 and 1.2sec (LH repeat 2-point phase scan) 4. Raise TF to 172kA (B=6.2T) - Engineering limit to 180kA Repeat steps 2 and 3 at higher field 5. Reduce TF to 139kA (B=5.0T) Repeat steps 2 and 3 at lower field 6. Return TF to 150kA (5.4T) and lower Ip to 500kA Repeat steps 2 and 3 at lower Ip 7. Raise Ip to 1.1MA Repeat steps 2 and 3 at higher Ip. 8. Return Ip to 800kA Repeat steps 2 and 3 at higher LH power |
| Session Leader Summaries |
| Entered: Apr 24 2008 05:04:05:720PM |
| Author: Greg Wallace |
| Disruptions ruled the day. After bringing LH up to 700kW successfully in the first two shots as planned, something broke inside the vacuum vessel and caused almost every subsequent shot to disrupt. Speculation is that something made of stainless steel became dislodged during shot 4 and has been protruding into the plasma since that time.
The only plasmas we were able to run full length were inner wall limited with large outer gaps. Moving the LH launcher in and out did not seem to make the problem go away, nor did switching from USN to LSN. Nothing is visibly out of place on any of the camera views. Unfortunately after a full day of disruptions we still do not seem to have cleaned up the source of the problem. |
| Physics Operator Summaries |
| Entered: Apr 24 2008 06:06:02:203PM |
| Author: Steve Wolfe |
Physop summary for Thursday April 24, 2008
MP#551 Penetration of accessible LH waves
SL: Wallace
PO: Wolfe
This was a BAD day. The first two shots (2 &3) went well,
but when we tried to move on to the main part of the run
with density sweeps during the LHCD we got a couple of
early disruptions, which were probably caused by high Mo
in the low density current ramp phase, resulting in hollow
temperature and current profiles. Some tweaking to the early
gas (seg 1 and 3) and current program seemed to help this, but
we then begain seeing steady Fe and Cr influxes from around 0.2sec
on, leading to high radiated power, high loop voltages, and disruptions
shortly after the turn on of the LH. The LH effect was confirmed by
moving the LH start from 0.7sec to 0.8sec on shot#9. However, there
was no indication that the launcher itself was the source
of the stainless that was apparently dominating the discharge. Raisng
the target density to try the second stage of the density ramp
program did not help.
At Earl's suggestion we changed from USN to LSN. After a few more
early disruptions we found the same Fe and Cr problem on shot#13.
Turning off the LH resulted in a longer plasma, but still disrupted at
1.1sec, with over 1.5MW radiated power and loop voltage around 2V. Zav
was over 2. Small changes to shape and gaps did not help. Some plasmas
made it to 1.4sec and died with VDE's caused (?) by asymmetric saturation
of power supplies, due to excessive voltsecond consumption.
On shot#20 we ran a shrinking limiter discharge loaded from 1071221002
(seg4),and found that the radiation and Fe levels dropped after the gap
grew beyond about 1.5 to 2cm. This seemeed to locate the source of ss on the
outboard side, not top or bottom. Running stationary outer gaps in the
range of 2.8cm with the inboard limiter reduced Prad but did not completely
eliminate the problem. Greg did get a semi-useful result
with a density ramp between 0.5 and 1.0e20 on shot#26, although the LH
faulted half-way through the pulse and the plasma distupted at 1.25sec;
there was some evidence of non-thermals early in the ramp and they disappeared
rapidly as the density rose. Unfortunately, the LH could not couple to
lower density plasmas with this large a gap, although we were able to
get ramps from ~3e19 to 6e19 on several shots in this configuration (#27,31).
Making the gap smaller, down to 2cm, resulted in disruption when the LH came
on, and high Prad before. An attempt to move the launcher in flush to the
guard limiter with the 2.8cm gap on shot#30 resulted in a disruption at LH
turn-on. We then pulled the launcher all the way out to its rest position
and verified that the Prad problem was still there (#31), and was worse
with the gap reduced to 1.6cm (#32), so it appears that the LH launcher
is not the source of the Fe. This was already fairly certain from the
camera view, but the view does not include the whole grill. Shots#33 and 34
were final attempts to get some data with the launcher moved back in,
but had a fizzle and an early disruption.
Bottom line is that we have something made of stainless sticking in
on the outboard side, and it isn't going away quietly. To the extent that
large outer gaps, of order 2.8cm, are acceptible, we may be able to live
with this situation. This does not seem compatible with LHCD. Based
on most of a day of banging away at it, the prospects for plasma machining
the object away do not seem good. It also seems unlikely that ecdc
is going to do the job, but it can't hurt to try. There is nothing
obviously glowing on any of the camera views, as far as I can see.
The other problem today was early disruptions which I attribute
to dirty startups, probably Mo. We've seen this sort of thing
before, especially with low density runs that unload the walls; usually
careful gas programming in the current rise can deal with this.
I don't think this issue is necessarily related to the stainless
problem. It did add to the frustration factor however, as did a number of fizzles. Later in the day the startup became very sensitive.
We started with the cryopump on, but discontinued it shortly after going
to lower null configuration. There was one small N2 leak, probably
from overcooling to get the central column cold. At some point it
was suggested that we turn off the DNB, and when we later tried to
turn it back on there were both datasystem problems (fixed by twf)
and possible startup problems, so it got turned back off again.
Scorecard:
Tests 1
Duds 0
Fizzles 5
Plasmas 28 (8 into rampdown)
======= ==
Shots 34
|
| Session Leader Comments | |||
| Apr 24 2008 09:15:12:530AM | 1080424002 | Greg Wallace | First shot of the day. Many trips. 6 bottom and 17 bottom looks like it might be the main problems. Will turn down klystrons 3 and 9. |
| Apr 24 2008 09:37:49:000AM | 1080424003 | Greg Wallace | Clean shot at 700kW. Moving on to low density ramp shot at 75 degrees. |
| Apr 24 2008 09:54:29:497AM | 1080424004 | Greg Wallace | Disruption at .27s. |
| Apr 24 2008 10:00:41:737AM | 1080424005 | Greg Wallace | Disruption at .32s. |
| Apr 24 2008 10:14:04:823AM | 1080424006 | Greg Wallace | Disruption at .53s on this shot. |
| Apr 24 2008 10:37:24:060AM | 1080424007 | Greg Wallace | Disruption at .71s. LH turns on quickly, then off when disruption happens. |
| Apr 24 2008 10:52:45:713AM | 1080424008 | Greg Wallace | Disruption at .71s again. Doesn't look like the LH is causing the problem on the camera view. Matt says lots of iron coming in around .3s.
Changing LH timing to be .8-1.3s for next shot. |
| Apr 24 2008 11:01:58:190AM | 1080424009 | Greg Wallace | Disrupts when LH turns on again, even after moving the LH timing to .8s. LH camera shows lots of hards hitting limiter but nothing obvious from the LH grill can be seen. Will try going to higher density scan for next shot to see if that fixes the disruption problem. |
| Apr 24 2008 11:20:18:077AM | 1080424010 | Greg Wallace | Disruption again when the LH turns on. Raising the density didn't seem to help much. At Earl's suggestion we are moving to a lower null plasma. |
| Apr 24 2008 11:33:47:853AM | 1080424011 | Greg Wallace | Disruption at .1s. |
| Apr 24 2008 11:38:58:203AM | 1080424012 | Greg Wallace | Disruption at .36s. |
| Apr 24 2008 12:09:17:083PM | 1080424013 | Greg Wallace | Plasma lasted until LH turned on, then disrupted at .71s. Lower null didn't seem to help. Try turning off LH for next shot. |
| Apr 24 2008 12:13:39:853PM | 1080424014 | Greg Wallace | Disruption at 1.1s without any LH. Looks like some underlying problem, and the LH is just pushing it over the edge. |
| Apr 24 2008 12:30:38:430PM | 1080424015 | Greg Wallace | Disruption at .735s with no LH power. Not looking good. |
| Apr 24 2008 01:06:35:300PM | 1080424016 | Greg Wallace | Disrupt at 1.4s. |
| Apr 24 2008 01:04:48:940PM | 1080424017 | Greg Wallace | Disrupt at 1.4s. |
| Apr 24 2008 01:27:40:317PM | 1080424018 | Greg Wallace | Disruption at 1.4s again. |
| Apr 24 2008 01:27:47:880PM | 1080424019 | Greg Wallace | Fizzle. |
| Apr 24 2008 02:18:14:323PM | 1080424020 | Greg Wallace | Full length plasma, inner wall limited with shrinking minor radius. |
| Apr 24 2008 02:17:43:590PM | 1080424021 | Greg Wallace | Fizzle. |
| Apr 24 2008 02:16:48:870PM | 1080424022 | Greg Wallace | Clean shot with no LH. Inner wall limited with large outer gap seemed to work. |
| Apr 24 2008 02:28:01:707PM | 1080424023 | Greg Wallace | Full length plasma. Will turn LH back on for next shot. |
| Apr 24 2008 03:14:48:050PM | 1080424024 | Greg Wallace | Fizzle. |
| Apr 24 2008 03:14:29:697PM | 1080424025 | Greg Wallace | Fizzle. |
| Apr 24 2008 03:12:42:757PM | 1080424026 | Greg Wallace | Got some LH in, plasma disrupted but after 1.2s. Next shot will turn up the power a little on klystron 9 (high intrinsic reflection seemed to cause the trip). Also will try to slow down the density ramp during the next shot. |
| Apr 24 2008 03:24:25:770PM | 1080424027 | Greg Wallace | Plasma ran clean, but LH could not couple in the early part of the discharge due to low density at the grill. We will attempt to decrease the outer gap to 2.0cm from 2.8cm to get more density at the grill. |
| Apr 24 2008 03:33:57:683PM | 1080424028 | Greg Wallace | Disruption at .35s. |
| Apr 24 2008 03:55:20:540PM | 1080424029 | Greg Wallace | Disruption at .72s. Looks like the smaller outer gap killed the plasma again. Moved in launcher to flush with limiter. Next shot will go back to larger outer gap. |
| Apr 24 2008 04:02:57:750PM | 1080424030 | Greg Wallace | Disruption again at .77s. Will move launcher all the way back for next shot. |
| Apr 24 2008 04:17:23:387PM | 1080424031 | Greg Wallace | Full length plasma, but Prad is still high. Will go to a smaller outer gap to see if the problem is still there. |
| Apr 24 2008 04:40:11:077PM | 1080424032 | Greg Wallace | Prad still high, plasma disrupts in rampdown. Outer gap around 1.5cm. Pushed launcher back in to flush with limiter, will have LH with the same plasma as shot 31. |
| Apr 24 2008 04:44:23:390PM | 1080424033 | Greg Wallace | Fizzle. |
| Apr 24 2008 04:57:51:980PM | 1080424034 | Greg Wallace | Disruption at .32 seconds. Last shot of the day. |
| Physics Operator Comments | |||
| Apr 24 2008 07:36:05:077AM | Steve Wolfe |
Set up for 1080424 = MP#551
Load from 1080408020 (upper null in seg3 active)
Seg1: pg4 from 26msec to 55msec for cryopump
rcur=1000
br_0=-.0005
ic_ef4u=-1355
Seg3: Change title to "0.8MA, 5.4T Upper Null"
Change nl04 to 0.4e20 flattop for shot#1,
move knots to 0.7,1.2sec for ramp in later shots
Notice the Ip gain switch is at 0.5sec, leave it there.
Load at 24-Apr-2008 07:34:03.00
Open tree /home/wolfe/pcs_scratch -1
Open tree done
| |
| Apr 24 2008 08:04:39:803AM | 1080424001 | Steve Wolfe | It turns out that after the DNB flood last night, ECDC was turned back on for several hours using B-side Main instead of B-top. Shot#1 will be a gas puff test (B-top and B-side Main to verify that things are working for today. Got gas, pg3 pushes it up to 0.8mTorr, looks like it's chopping ok. Seems to be working correctly. |
| Apr 24 2008 09:08:02:040AM | 1080424002 | Steve Wolfe | Shot#2: Try for 4e19, 800kA plasma plasma, got hard xrays during LH Got more density than requested, up to 7.5e19 early, around 5e19 during LH pulse. Faulting on LH Bouncy startup, but also some hesitation, not sure which way to go on gas, which is at .06mTorr. Bz looks a bit negative. Back off on pg3 in seg1, try to reduce early density. |
| Apr 24 2008 09:13:07:917AM | 1080424002 | Steve Wolfe | Shot#3: decrease pg3 in seg1 to reduce early nl04 Leave pg4 alone, check current rise next shot. Delay for computer hang - bolometer cpci store |
| Apr 24 2008 09:37:25:373AM | 1080424003 | Steve Wolfe | Shot#3: decrease pg3 in seg1 to reduce early nl04 Leave pg4 alone, check current rise next shot. Delay for computer hang - bolometer cpci store Reduce pg4 to 50msec while I'm waiting Into INIT after 29minutes, Sue had to recool cryo Plasma, early runaways, shouldn't have dropped pg4? nl04 down to 4e19, more or less. Startup is a bit ragged. p0 down to .053mTorr. Next: move on to density ramps |
| Apr 24 2008 09:49:09:257AM | 1080424004 | Steve Wolfe | Shot#4: move on to density ramp#2, 3 to 6e19 from 0.7 to 1.2sec No seg 1 changes. Another computer delay. Early disruption, runaways in startup. Next: raise pg4, put back some seg1 pg3 |
| Apr 24 2008 10:09:31:367AM | 1080424005 | Steve Wolfe |
Shot#5: pg4 from 50 to 55msec, increase pg3 in seg1,
ic_ef4u from -1355 to -1345, hold off on rcur offset for now
density ramp#2, 3 to 6e19 from 0.7 to 1.2sec
Another early disruption. No runways, goes resistive after .1sec
Hollow Te profiles
I think I need to put back some more early gas.
|
| Apr 24 2008 10:38:16:967AM | 1080424007 | Steve Wolfe | Shot#7: Tweak current rise in seg3, copy seg1 pg3 from shot#3 (which is lower) Makes it to 0.7sec, but had a minidisruption at .12sec suspiciously close to crowbar? Sawteeth start at .216sec, looks ok, if somewhat lagging on Ip up until just after LH turn on. Then gets an injection. Density is too high at 0.7sec, 5e19. Next: reduce pg3 in seg3 to 20V at 0.1sec |
| Apr 24 2008 10:52:14:463AM | 1080424008 | Steve Wolfe | Shot#8: reduce pg3 in seg3 to 20V at 0.1sec, try again ITG=1.2e-7 in INIT Still disrupting, almost exactly the same time. I don't see any increase in pg3 demand at 0.7sec, probably because density is already above 3e19 Try delaying LH until 0.8sec |
| Apr 24 2008 11:01:21:063AM | 1080424009 | Steve Wolfe | Shot#9: Try delaying LH until 0.8sec, recalculate nl04 predictor. disrupts at 0.8sec, just after lh turn on. It seems to be associated with LH, but not obviously coming out of the antenna. Try raising density and do ramp#3 (.5 to 1.0e20) |
| Apr 24 2008 11:12:36:430AM | 1080424010 | Steve Wolfe | Shot#10: Try raising density and do ramp#3 (.5 to 1.0e20) LH back to 0.7sec Disruption at 0.71sec Try going to a lower null case (Earl's suggestion) |
| Apr 24 2008 11:32:05:697AM | 1080424011 | Steve Wolfe | Shot#11: Import seg2 from 108032007 (which was lower null 6.2T, 800kA) and change nl04 to 3e19 (flat) and TF to -150000A. Cryo won't do much for this, but leave it on for now. Seg2 on, seg3 off. early disruption 0.1sec, bad startup, all runaways. Pressure went up a little, almost lost it at 25msec, never got above 250kA. N2 peak came up. Vesssel temperature dropped before shot during delay for CC cooling. Possible vessel leak, possible cryopump leak? Next: try again |
| Apr 24 2008 11:45:32:550AM | 1080424012 | Steve Wolfe | Shot#12: Try again with seg2 from 108032007 (which was lower null 6.2T, 800kA) and change nl04 to 3e19 (flat) and TF to -150000A. Turn off cryopump for this shot. PG4 to 25msec Runaways early and disrupts at 0.36sec, only gets to 600kA. Back to hollow current profiles in current rise? Next: Add some pg3 in seg2, increase nl04 to 5e19 |
| Apr 24 2008 12:08:45:880PM | 1080424013 | Steve Wolfe | Shot#13: Add some pg3 in seg2 (copy seg1), increase nl04 to 5e19 Pg4 from 25 to 27msec Disrupts at 0.718sec, just after LH turn on. @pi is still high from 0.2sec or earlier, and Vloop is over 1.5V, rises at 0.65 for gain switch. Runaways aren't bad, nl04 is flat at 0.55e19 Next: Turn off LH |
| Apr 24 2008 12:21:50:813PM | 1080424014 | Steve Wolfe | Shot#14: Turn off LH. Also turn off dpcs_ftae2 routine (why was this on?) Plasma to 1.1sec, bolo starts rising smoothly after 1sec Voltage goes up to 2V. Apparently something iron is sticking in somewhere. It's not on top, since this one is solidly lower null. Strike point is high on outer divertor, could move rxl in, but why? Next: increase clearin, move rxl in |
| Apr 24 2008 12:35:38:870PM | 1080424015 | Steve Wolfe | Shot#15: increase clearin from 0 to .003, move rxl in to 0 Disrupting at 0.73, gaps are bigger, strike didn't move much Matt says chromex is seeing something on aside view of inner wall? |
| Apr 24 2008 12:48:59:677PM | 1080424016 | Steve Wolfe | Shot#16: Try raising density to 7e19 plasma disrupts at 1.4sec This one may go vde; n/nc is getting up there. EF1U is railing. Next: back off clearin, zxu, try to get one to run through |
| Apr 24 2008 01:01:42:310PM | 1080424017 | Steve Wolfe | Shot#17: back off clearin to 0 frim +0.003, zxu from .05 to 0.03 try to get one to run through plasma to 1.4sec, very similar to 16. Still going vertically, ef1U still railing at 1.3sec, OH2U and OH1 also end up railing, voltage is almost 2V in flattop, Zave=2, bolo says 1.6MW Next: Nl04 back down to 6e19 |
| Apr 24 2008 01:20:57:733PM | 1080424018 | Steve Wolfe | Shot#18: Nl04 back down to 6e19,rxl from 0 to -.01 plasma to 1.4sec Xpoint moved over, density is a little lower still railing things. Try a limiter case with a big outer gap. I think it will be worse. |
| Apr 24 2008 01:29:01:003PM | 1080424019 | Steve Wolfe | Shot#19: Load from 1071221002 (shriking limiter plasma in seg4) import startup from -1 seg1. turned beam off fizzle, probably raised the pressure by closing the beam gate valve. Next: drop pg4 |
| Apr 24 2008 01:48:00:287PM | 1080424020 | Steve Wolfe | Shot#20: pg4 from 27 to 24msec Load from 1071221002 (shriking limiter plasma in seg4) import startup from -1 seg1. turned beam off fizzle, probably raised the pressure by closing the beam gate valve. plasma full length Prad starts dropping at 0.6sec, when outer gap is 1.5cm and starts shrinking. Maybe it means that the stainless is on the outside? Next: ? |
| Apr 24 2008 01:57:11:917PM | 1080424021 | Steve Wolfe | Shot#21: Hold the shape as at 0.7sec on shot#20, Turn nl04 feedback gain back on after 0.6sec! Fizzle. Bounced outside. Next: raise pg4 again |
| Apr 24 2008 02:18:36:200PM | 1080424022 | Steve Wolfe | Shot#22: raise pg4 from 24 to 26msec Still trying for limiter discharge with ~2cm outer gap plasma with early runaways, but it ran full length. Prad is lower after the gap moves to 2.9cm Almost lost it in startup again. Next: go to 800ka, 5e19, keep outer gap as on this one |
| Apr 24 2008 02:41:15:687PM | 1080424024 | Steve Wolfe | Shot#24: Turn on LH again: 800ka, 5e19, rcur flat at 0.643, limited. put in a density ramp from 0.7 to 1.2sec (0.5 to 1.0e20), with 70V pg3 puff 0.7 to 0.9sec to help it along And another fizzle. Drop the gas again |
| Apr 24 2008 02:52:21:430PM | 1080424025 | Steve Wolfe | Shot#25: g4 from 26 to 23msec Turn on LH again: 800ka, 5e19, rcur flat at 0.643, limited. put in a density ramp from 0.7 to 1.2sec (0.5 to 1.0e20), with 70V pg3 puff 0.7 to 0.9sec to help it along Another fizzle. This one bounces outside. |
| Apr 24 2008 03:09:18:113PM | 1080424026 | Steve Wolfe | Shot#26: rcur offset from 1000 to 1800, br_0 from 0 to -.0003 Turn on LH again: 800ka, 5e19, rcur flat at 0.643, limited. put in a density ramp from 0.7 to 1.2sec (0.5 to 1.0e20), with 70V pg3 puff 0.7 to 0.9sec to help it along plasma disrupted at 1.25sec, density goes to 1.0 on the pg3 puff, then falls. LH faults after .93sec Actually LH is on for the whole density rise. Next: drop density and slow ramp down |
| Apr 24 2008 03:22:39:560PM | 1080424027 | Steve Wolfe | Shot#27: start nl04 at 2e19, raise to 6e19 Leave seg1 alone and see if we can get plasma at all. plasma full length, density ramp is in two steps LH is faulting all the way through. Can't have everything. Next: reenable DNB, no change in pg4. What to do about LH??? |
| Apr 24 2008 03:42:38:797PM | 1080424028 | Steve Wolfe | Shot#28: Decrease outer gap by 8mm (rcur up by 4mm, to .647 disruption at .345sec. This one looks like hollow current again, I don't think it's the rcur shift, although the pivot is at 0.25sec Matt says this is a Mo problem again |
| Apr 24 2008 03:51:58:947PM | 1080424029 | Steve Wolfe | Shot#29: Delay rcur shift to after 0.4sec dnb data acquisition is hanging, so turn them off again, no change to pg4. plasma disrupts at 0.72sec, something comes in at 0.66, Prad is up but not as high as it was. Next: move launcher flush, put gap back to 2.8cm |
| Apr 24 2008 04:03:41:547PM | 1080424030 | Steve Wolfe | Shot#30: move launcher flush, put gap back to 2.8cm (rcur=.643) plasma disrupted at .77sec Prad is steady around 1MW, loop voltage 1.6 before LH. Next: pull launcher all the way out. |
| Apr 24 2008 04:17:10:950PM | 1080424031 | Steve Wolfe | Shot#31: pull launcher all the way out, see if it really is the source. NO pcs changes, repeat the same shot. plasma full length, some runaways building through the shot. Prad still high, although loop voltage is down to 1.3V later in shot. I don't think it's really better. Next: Move outer gap down to 1.6cm |
| Apr 24 2008 04:34:42:400PM | 1080424032 | Steve Wolfe | Shot#32: Move outer gap down to 1.6cm, rcur out by 6mm to .649 plasma to 1.8sec, Prad is up to 1.5MW or so again, Vloop~1.7, railing EF1's EF2's, OH2L. outer gap is 1.5cm until things start to rail, then down to 5mm around 1.6sec The problem is still there. Next: Push the launcher back in, since that's not the problem |
| Apr 24 2008 04:45:52:237PM | 1080424033 | Steve Wolfe | Shot#33: Push the launcher back in, since that's not the problem Go back to 2.8cm outer gap like 31 (rcur=.643) fizzle |
| Apr 24 2008 04:58:00:230PM | 1080424034 | Steve Wolfe | Shot#34: Br_0 to -.0005, pg4 from 23 to 22msec Push the launcher back in, since that's not the problem Go back to 2.8cm outer gap like 31 (rcur=.643) disrupts at .35sec, this one is Mo in the current rise again. END OF RUN |
| Engineering Operator Comments | ||||
| Shot | Time | Type | Status | Comment |
| 1 | 07:58:45:907AM | Test | Ok | cycle test with gas |
| 2 | 08:57:58:610AM | Plasma | Ok | |
| 3 | 09:29:39:307AM | Plasma | Ok | |
| 4 | 09:45:05:443AM | Plasma | Ok | |
| 5 | 09:57:41:030AM | Plasma | Ok | |
| 6 | 10:10:16:837AM | Plasma | Ok | |
| 7 | 10:27:14:820AM | Plasma | Ok | |
| 8 | 10:39:44:547AM | Plasma | Ok | |
| 9 | 10:53:55:540AM | Plasma | Ok | |
| 10 | 11:07:06:067AM | Plasma | Ok | |
| 11 | 11:23:23:330AM | Plasma | Ok | |
| 12 | 11:36:27:090AM | Plasma | Bad | OH1 self powered crkt fired |
| 13 | 11:49:23:867AM | Plasma | Ok | |
| 14 | 12:09:50:647PM | Plasma | Ok | |
| 15 | 12:25:11:957PM | Plasma | Ok | |
| 16 | 12:41:52:670PM | Plasma | Ok | |
| 17 | 12:54:24:587PM | Plasma | Ok | |
| 18 | 01:09:41:583PM | Plasma | Ok | |
| 19 | 01:25:46:080PM | Plasma | Ok | |
| 20 | 01:38:27:793PM | Plasma | Ok | |
| 21 | 01:54:27:620PM | Plasma | Ok | |
| 22 | 02:08:19:130PM | Plasma | Ok | |
| 23 | 02:24:06:047PM | Plasma | Ok | |
| 24 | 02:36:43:400PM | Plasma | Ok | |
| 25 | 02:49:16:440PM | Plasma | Ok | |
| 26 | 03:01:39:607PM | Plasma | Ok | |
| 27 | 03:16:22:197PM | Plasma | Ok | |
| 28 | 03:28:49:513PM | Plasma | Ok | |
| 29 | 03:42:22:640PM | Plasma | Ok | |
| 30 | 03:57:12:700PM | Plasma | Ok | |
| 31 | 04:11:37:273PM | Plasma | Ok | |
| 32 | 04:24:55:657PM | Plasma | Ok | |
| 33 | 04:42:15:263PM | Plasma | Ok | |
| 34 | 04:55:19:510PM | Plasma | Ok | |
| System Availability | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Apr 24 2008 08:57:53:047AM | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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