Alcator C-Mod Run 1060620 Information

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Miniproposals
Miniproposal:356
Date Filed:11/12/2003
Title:Mode Conversion Current Drive Experiments
First Author:Alexandre Parisot
Session Leader:Alexandre Parisot (shots 5-9)
Miniproposal:447
Date Filed: 4/4/2006
Title:MCCD experiments during current ramp-up
First Author:Alexandre Parisot
Session Leader:Alexandre Parisot (shots 1-4)
Session Leader:Alexandre Parisot (shots 9-31)

Operators
Session leader(s):Alexandre Parisot,Alexandre Parisot,Alexandre Parisot
Physics operator(s):Steve Wolfe
Engineering operator(s):Bill Cochran,Sam Pierson,Bill Parkin

Engineering Operator Run Comment
MP#447 MCCD during current rampup

Session Leader Plans
Entered: Jun 19 2006 04:59:58:170PM
Author: Alexandre Parisot

MP#447 MCCD experiments during ramp-up
Session leader: Parisot
Physics operator: Wolfe

This is a continuation of last Wednesday's run. We will assess the status of the two problems we encountered last Wednesday: the pickup on magnetics and J-port performance, and investigate these problems further. Depending on the results, we will try to get some physics following the plan in the MP:

1] Start with 1060614031. While bringing J-port up in power and monitoring electron heating,
bring the density down by reducing the D and 3He puffs. A good target is nl04 < 0.7 x 10^19 m^-2

2] Scan phasing [co, counter and heating] and monitor changes in magnetics and sawtooth onset time.

3] With ~ 3 MW from D and E, obtain Alfven cascade activity on PCI, then add power from J-port and
scan phasing [co, counter and heating].

Physics Operators Plans
Entered: Jun 19 2006 06:04:38:757PM
Author: Steve Wolfe
Engineering setup and Physop plan for Tuesday, 20-Jun-2006
-----------------------------------------------------------

MP#447 MCCD during current rampup
SL: Parisot
PO: Wolfe

ECDC overnight in D2 at 2e-4Torr

Power Systems as on 1060614031
Acoil configuration standard: +Dtop -Dbot -Jtop +Jbot, enabled

Gas setup:
----------

fill B-top with 6psi D2, hybrid enabled (PG4)
fill B-side lower with 1psi Argon + 1psi Neon, hybrid DISABLED (PG1)
leave B-side upper with 15psi He3, hybrid ENABLED (PG2)
fill B-main with 40psi D2, hybrid ENABLED (PG3)
fill NINJA with 10psi D2, Disabled

Enable VUV, ECE, Zbolo shutter (assuming no vacuum problems)
Do not enable DNB gate valve.
TORVAC gate valves open during pulse

FMIT#1,2,3,4 in RUN-ON by 08:30

Plan
----

Load 1060614031 (800kA, 5e19, upper null, short current pulse, in seg4)
Set PG2 puff to total 120msec (Seg1 and seg4)
Fix B21_PROJ/Acoil_cur programming in Seg4 (integrator timing, zero ACOIL_CUR
feedforward)

NOTE: Leave fizzle detector gate at 1.8sec, so we'll force reverse oh swings
after these short low-density shots. 

Ian was finding he needed Br0=-1mT, which may be consistent with the no-f11
predictors. We'll also probably need to play a little with Bz rise rate. 

See SL_PLAN for remainder of run plan. 


Session Leader Summaries
Entered: Jun 20 2006 05:30:26:770PM
Author: Alexandre Parisot
The pickup problems from last Wednesday were not encountered during this run, and
we devoted the first part of the run to loop voltage comparisons. J-port ran well
at 2.2 MW, with low densities (nl04 ~ 0.6) and Zeff < 3 initially. However, after
one or two shots at high power, Zeff was at 6 and the radiated power was such that
we could not raise the temperature above 4 keV with 4 MW RF. These conditions are
not favorable for net current drive, and not any better than in the experiments last summer.
Therefore we decided to abandon MP#356 for now.

On the current ramp-up experiments (MP#447), we were able to obtain very good central heating
(Te up to 6 keV) with ~ 3 MW from D&E and 2 MW from J-port. In these conditions, we
had good comparison discharges between co- and counter-current drive. However, we
did not observe Alfven cascade activity on the PCI, even with 2.8 MW from D&E or when matching
the plasma parameters from prior sucessfull Alfven cascade experiments in 2004.

Initial analysis of the comparison discharges showed little or no differences in the
loop evolution or internal inductance between co- and current drive during ramp-up.
Some differences were observed in the onset and characteristics of sawtooth oscillations,
and will be investigated further.

Physics Operator Summaries
Entered: Jun 20 2006 06:11:07:907PM
Author: Steve Wolfe
Physop summary for Tuesday, 20-Jun-2006
MP#447 MCCD during current ramp 
 (with a small diversion into MP#356 MCCD during flattop)
SL: Parisot
PO: wolfe

The machine and RF ran pretty well today, though it's not clear
that the physics cooperated. Evidence for current drive was, IMHO,
pretty slim, although Wukie thinks that the sawtooth changes were
well-correlated with the J phasing. See the SL_SUMMARY for details.

The major operational questions going into the run were
whether we could get high power from J-port at 50MHz and if the 
pickup observed last week on the magnetics and other signals was 
gone. Today there seemed to be no problem getting the J-port power up 
to 2 to 2.5MW, and the pickup was completely absent. It is not clear 
why in either case, but the RF group did add capacitance to the 
DC break and did some RF glow (multipactor), which may have helped.

We started with the setup of the last shot from 1060614031, with
the early He3 puff changed to 120msec, and quickly noted that the
RF pickup was gone. For shot 3 we reloaded 1060614012, which was a 
600kA flattop MCCD case, and confirmed that the pickup on the 
magnetics was also gone in this case. We then spent a couple of
hours revisiting the MP#356 shots, looking for changes in loop 
voltage. These shots were somewhat disruptive, but the RF performed
well, and we did some variation in the He3 puff and phasing. There
were, however, no obvious changes in loop voltage that might be 
indicative of MCCD. 

At shot 9 we went back to the current ramp study, trying to get a
case with Alfven cascades that would be sensitive to changes in
the q profile. While the RF was successful in injecting as early 
as 0.1sec, and in a few cases even earlier, we did not observe
any cascade modes in this sequence. The density may have been too
high, and we tried eliminating the PG3 puff in segment 1, and 
eventually even turned off the He3 puff, and the J-port pulse,
in an effort to recover the conditions for the cascades. It was 
pointed out that the cascade "trophy shot" 1040406018 had a somewhat
faster current rise than we were getting, so we also tried to increase
the Ip ramp.

On shots #21 and 22 I turned on Ip feedback in segment 1 (see logbook
for the settings) beginning at .06 seconds, and was somewhat successful
in increasing the current at 0.1 sec from 505ka to 575ka, which
was close to the value on 1040406018, but PCI still did not observe
any cascades. The use of Ip feedback in segment 1 may prove useful for
other experiments, and did not seem to result in any problems. There
was still some headroom on the gain, and I did not try turning on 
derivative gain, which might have helped as well. The power supply
demands did not seem to be out of range for a P gain=4.0.

For shot#23 we reloaded from #14 and concentrated on sawtooth changes
as the prime indicator of current drive. The remainder of the run 
was done with total power approaching 5MW, and essentially every shot
disrupted by about 0.5sec. There were obvious injections from the 
J antenna corner and elsewhere, and increasing Prad that looked like 
local heating rather than discrete events. Since the power was not that 
much higher than in shots #9-16, it is not clear why the disruptivity
was so much higher, unless we were actually ratcheting the temperature
somewhere. At first I thought the disruptions might be related to OH1 
crossover or to the Ip gain switch (which I moved later), but this turns
out not to be the case. 

Startups were quite robust, with only one fizzle (#19) and 
one hard runaway shot (#29). As was the case last week, early He3 puffing
was no problem, with the possible caveat that the early density could
not be reduced below about 6e19; however, some of this density was 
probably due to the early RF rather than the puff.  The main change 
to the startup today was to increase the RCUR offset from 1600 to 2000,
in order to increase the Bz ramp rate. This seemed to be successful. Aside
from that, I made a small tweak to EF4 early in the day, and made minor
tweaks to the PG4 puff in response to runaways and disruptions.   

While the current drive was hard to find, the heating in these discharges
was quite impressive, with Te0 up to 6keV on many shots before the
start of sawtoothing. Amanda points
out that the peak temperature was typically around 0.70m, about 2cm outside
the EFIT "RMAGX", which is not unreasonable considering the EFIT limitations
on the q0 and profile functions.

Scorecard:
-----------

  Tests    0
  Duds     0
  Fizzles  1
  Plasmas 30
 ======== ==
  Shots   31

Session Leader Comments
Jun 20 2006 09:19:02:320AM1060620001Alexandre ParisotJ-port ran 1.1 MW. D and E faulted out (mismatched).
No pickup from J-port (heating phase).
FRC-ECE is not working.

Next: Lower D puff during segment 1 to get lower nl04.
Go to counter-current drive.
Jun 20 2006 10:03:48:963AM1060620002Alexandre ParisotJ-port ran, no pickup. D and E are here too.
FRC-ECE data is offset, seems to trigger at 1 sec.

Next: Load 1060614012 to see if pickup is there.
Jun 20 2006 10:02:04:463AM1060620003Alexandre ParisotDisrupted at 1.13 sec. J ran to 2.5 MW, heating phase.
FRC-ECE is back. We're in business for loop voltage physics !
Not seeing much electron heating though.

Next: 3He puff duration to 200 ms.
Jun 20 2006 10:09:52:840AM1060620004Alexandre ParisotDisrupted at 0.6sec.
Jun 20 2006 10:14:44:110AM1060620004Alexandre ParisotDisrupted at 0.6sec.

Since the pickup is apparently gone, we'll spend a couple of shots on MP#356.
The conditions are not optimal (no boronization) but Zeff ~ 2.5 and ne0 ~ 1.4 x 10^20 m^-3, which is good. We'll do some phasing scans after making sure the 3He concentration is right.

After this, we'll switch back to MP#447.
Jun 20 2006 10:34:29:273AM1060620005Alexandre ParisotDisrupted at 1.08sec. J-port ran with programmed notches.
The 3He monitor has less signal than last Wednesday, any problem with the valve ?

Next. Try turning the valve on by 150ms, i.e [150-400ms]
Jun 20 2006 10:47:34:590AM1060620006Alexandre ParisotLooks like the 3He is making it in. The break-in-slope data is clearer this time.
Concentration estimate is ~ 20 %.

Next: Ramp D&E to 2MW to figure out the H-mode threshold (we want to stay right below it). Lower puff time by 50 ms.
Jun 20 2006 11:19:35:853AM1060620008Alexandre ParisotJ-port will not run above 2 MW, the radiated power is very high.
Looks like we will not go anywhere with the loop voltage measurements.

Next: Go back to the ramp-up experiments.

Jun 20 2006 11:33:46:127AM1060620009Alexandre ParisotGood starting point for ramp-up studies. 1.5 MW from J-port, 2 from D&E.
Density goes up to nl04 = 0.8
Some hints of faint activity on the PCI.

Next: Raise power.
Jun 20 2006 11:54:43:537AM1060620010Alexandre ParisotE struggled. Nothing on the PCI.
J-port (co-current drive) 2 faults early, match is good.

Next: Add notches to J-port after 0.4 sec, go to opposite phasing.
Jun 20 2006 12:08:51:257PM1060620011Alexandre ParisotGood shot.

Next: Opposite phasing again.
Jun 20 2006 12:19:33:950PM1060620012Alexandre ParisotHigh voltage fault on J after 220 ms.
J-port co-current drive.

Next: Repeat. More power from D and E.
Jun 20 2006 12:36:14:870PM1060620013Alexandre ParisotGood shot. J-port ran to 350 ms.
Very faint data on the PCI: is the density too high ?

Next: Opposite phasing.
Jun 20 2006 12:51:08:480PM1060620014Alexandre ParisotGood shot. -90deg. Very good comparison with shot 13.

Next: Raise power from D&E.
Jun 20 2006 01:02:27:227PM1060620015Alexandre ParisotStill nothing on the PCI. We need a slower nl04 rise.

Next: No D puff in segment 1, puff 3He [0-100ms]
Jun 20 2006 01:16:46:563PM1060620016Alexandre ParisotDensity did not go down.

Next: Lower 3He puff to 50 ms.
Jun 20 2006 01:19:53:927PM1060620016Alexandre ParisotDensity did not go down.

Next: Lower 3He puff to 50 ms. Put some notches on J-port.
Jun 20 2006 01:34:38:507PM1060620017Alexandre ParisotDensity did not go down more.
It is coming from the antenna (or the RF) ?
We have some good break-in-slope at 0.44, when JT's He II monitor crosses the value it had in the flattop discharges.

Next: No 3He.
Jun 20 2006 01:54:34:733PM1060620018Alexandre ParisotOK, 3He seems way down, no break-in-slope data.
It looks like we need that 3He puff, but we won't get lower density then.

Next: Put back 3He puff 0-100ms.

Jun 20 2006 02:00:54:720PM1060620019Alexandre ParisotFizzle.

Next: Turn off J-port. No 3He puff, look at Afven cascades, hopefully with less nl04.

Jun 20 2006 02:24:55:813PM1060620020Alexandre ParisotGood shot. J-port off. Still nothing on the PCI.

Next: Try to get a faster current rise, turn on D&E at 70 ms.
Jun 20 2006 03:10:01:283PM1060620022Alexandre ParisotStill nothing on the PCI.

Next: Reload 14.
Jun 20 2006 03:17:51:067PM1060620023Alexandre ParisotDisrupted at 0.50s. Got 5 keV.

Next: 5.35T
Jun 20 2006 03:31:07:960PM1060620024Alexandre ParisotGood shot.

Next: Opposite phasing.
Jun 20 2006 03:49:12:643PM1060620025Alexandre ParisotJ faults early.

Next: Repeat.
Jun 20 2006 03:58:45:477PM1060620026Alexandre ParisotGood comparison with shot 24

Next: Increase 3He puff duration to 150 ms.
Jun 20 2006 04:12:00:820PM1060620027Alexandre ParisotNext: Opposite phasing
Jun 20 2006 04:32:22:000PM1060620028Alexandre ParisotNext: Heating phasing

Physics Operator Comments
Jun 20 2006 07:48:58:723AMSteve Wolfe
Setting up for run 1060620:
Bring up pcs3-Beta. Got the dpcs config_id warning, which 
implies nobody has used the beta version since 2-Jun. 

Load_from 1060614031. Active segment is seg4, 0.8MA Upper Null
Ip rampdown starts at 1sec, TF rampdown normal. NL04 rampdown is
also not until 1.6sec, which might be a mistake if it weren't
at such a low density (5e19) anyway.

In seg1 Change PG2 puff to be [0,.120]sec
Copy PG2 trace from seg1 to seg4. 
In seg4, zero acoil_cur waveform, integrator C gate to .25sec
Load at 20-Jun-2006 07:48:26.00
Open tree /home/wolfe/pcs_scratch      -1
Open tree done


Jun 20 2006 09:15:24:493AM1060620001Steve Wolfe
Shot#1: plasma, full (short) length, some injections
Bz looks a bit negative in startup, but who knows what the trace 
really means now. No runaways. Slow current rise. 
Not seeing pickup from J on the magnetics

Next: reduce pg3 puff in seg1


Jun 20 2006 09:43:28:143AM1060620002Steve Wolfe
Shot#2:  reduce pg3 puff in seg1, ic_ef4 from -1325 to -1315
plasma, maybe some runaways? Yes, it bounced on startup. 
Early density still too high. 

Next: Load from 1060614012 to check on pickup. 
Load the whole shot, startup and all.

Jun 20 2006 09:56:59:820AM1060620003Steve Wolfe
Shot#3:   Load from 1060614012 to check on pickup. 
Load the whole shot, startup and all. 
Note that this shot used seg3 active. It also has the
bad Acoil_cur and integrator gate, and a different He3
puff, as well as different current and maybe field? 

plasma: disrupted at 1.2sec, no pickup on magnetics. 
Next: Change of plans, SL wants to use this shot instead
of the current rise. 

Jun 20 2006 10:12:53:437AM1060620004Steve Wolfe
Shot#4: Ef4 from -1335 to -1325, try to fix late bd (6.5ms)
Acoil_cur to zero in seg3, IntC gate to .3sec
Increase PG2 puff from 175ms to 200ms

Early disruption, I think this shot is from before Ian fixed the
vertical instability problem? No this one disrupts at .635sec; we're
still seeing the vertical burst at 0.3sec, but that's not what killed it.

This looks like an injection, definite runaways early, and a bounce
in startup. Could be related. 

Next: increase pg4, rcur offset, try to fix the startup. 

Jun 20 2006 10:34:17:117AM1060620005Steve Wolfe
Shot#5: PG4 from 19 to 22msec, RCUR offset from 1600 to 2000
Delay Ip gain switch from 0.5 to 0.7sec (after crossover)
Still disrupting in flattop, around 1.1sec. 
Startup looks better, no bounce no runaways. 
Doesn't look like a locked mode, I think we're still getting
hit by injections. Gas is off after 0.1sec, nl04 running around
0.5e20. Alex thinks the He3 valve isn't giving enough puff. 
Next: increase pg2 (earlier)

Jun 20 2006 10:45:59:590AM1060620006Steve Wolfe
Shot#6: Pg2 puff from .15 to .4sec.
Plasma into ramp-down, got more He3 according to JT's signal

Next: reduce he3 (.15 to .35)

Jun 20 2006 11:02:38:517AM1060620007Steve Wolfe
Shot#7: Pg2 puff from .15 to .35sec.
Rf Adding D&E for heating, hope it doesn't make the injections worse.

plasma to 1.2sec, 4.4MW when it disrupts, lots of injections.
Looks like something heats up at 0.95sec or so. 

Next: repeat with co-CD phasing

Jun 20 2006 11:17:01:697AM1060620008Steve Wolfe
Shot#8: Repeat, change phase. 
plasma to 1.42sec, got some runaways early on this one,
Looks like J faults around .8sec

Back to the current ramp case. 
Back to shot 2 and lower pg3 in seg1. 
Put back the other startup tweaks I've done since. 

Jun 20 2006 11:32:16:467AM1060620009Steve Wolfe
Shot#9: Reload shot 2, Back to the original program.
PG4 to 22msec, RCUR offset to 2000, leave Ic_ef4 at -1315
Drop PG3 in seg1 and in seg4

plasma full (short) length. Early density at 8e19, flattop
around 2e19. The PG3 feedforward is negative after 0.7sec or so, 
I'll just zero it. 

Jun 20 2006 11:52:57:397AM1060620010Steve Wolfe
Shot#10: Zero Seg4 PG3 puff, otherwise repeat. 
20 minute delay for data system hang.

plasma ok, flattop density still low, around 3e19.
Still getting some early runaway bursting. 
Getting up to 4.4MW of RF, but E and J look a little 
ratty early. 

Next: No changes

Jun 20 2006 12:04:57:537PM1060620011Steve Wolfe
Shot#11: plasma, no runaways this time
E looks clean, J still has a few faults. 

next: no PCS changes

Jun 20 2006 12:17:19:770PM1060620012Steve Wolfe
Shot#12: No PCS change, reverse phasing again
plasma ok, RF faulted (J) around 220msec

next: no PCS changes



Jun 20 2006 12:31:12:357PM1060620013Steve Wolfe
Shot#13: No PCS change, try that one again
plasma ok, looks like a clean pulse until J faults out at .34sec

next: No PCS changes



Jun 20 2006 12:52:02:730PM1060620014Steve Wolfe
Shot#14: No PCS changes, reverse phase again
plasma ok. Looks like some injections starting around .37sec
RF clean before that, over 4.6MW. 
Wide 2 view shows something lighting up near G-port

next: No PCS changes


Jun 20 2006 01:02:28:100PM1060620015Steve Wolfe
Shot#15: plasma ok. RF ok, no cascades
next: reduce He3 puff to 0.1sec, eliminate pg3 in seg1 completely
trying to reduce density in current rise

Jun 20 2006 01:15:46:267PM1060620016Steve Wolfe
Shot#16:  reduce He3 puff to 0.1sec, eliminate pg3 in seg1 completely
trying to reduce density in current rise
plasma, density didn't drop much if at all. 

next: drop He3 to 50msec (all in seg1)

Jun 20 2006 01:31:13:307PM1060620017Steve Wolfe
Shot#17: drop He3 to 50msec (0 to .05s)
plasma, short. disruption at 0.5sec. PF breaker pulled after; OH1 xbar.
Density is still over 8e19 at .33sec

Next: Eliminate He3 puff completely!

Jun 20 2006 01:56:30:687PM1060620018Steve Wolfe
Shot#18: Eliminate He3 puff completely!
plasma, short. Disrupts at .5sec. 
Density is down to 0.6e20. He monitor signal is well down, about 10% of
max level seen earlier. Prad is up. Te looks very high, 
neutrons too. No break in slope on the ECE profile at the notches,
so it's not clear we're getting electron heating now. 

Next: back to 100ms He3

Jun 20 2006 01:58:15:470PM1060620019Steve Wolfe
Shot#19: back to 100ms He3
Fizzle. One disruption to many, I guess.


Jun 20 2006 02:24:40:687PM1060620020Steve Wolfe
Shot#20: Turn He3 back off, turn off J-port for a shot
to see if the cascades come back. Hopefully the plasma will 
just come back with no tweaks; it looked like it was just a bit slow on 19.

Another disruption, later this time around 0.8sec. RF crowbarred
Big runaway buildup after the RF is off? nl04 in flattop is around 0.35e20
startup is still a little slow, maybe I'd better drop pg4 a little next time.




Jun 20 2006 02:48:51:763PM1060620021Steve Wolfe
Shot#21: PG3 puff back on in seg1, drop pg4 from 22 to 20ms
Turn on IP gain in seg1: Gain =2 after .06sec, Program 650kA at 0.1sec
Controller=XCONTIHH, TAUOPT=0.3
Trying to get a faster current rise, as on 1040406018 (which got it naturally).

Disrupted early, .35sec. Current rise is very slightly faster 525 vs 505ka
at 100msec
Looks like runaways before the RF, which turned on at .08sec this shot.

next shot: Increase Ip gain to 4 in seg1

Jun 20 2006 03:04:29:497PM1060620022Steve Wolfe
Shot#22: Increase Ip gain to 4 in seg1, raise Ip  program at 0.1
and 0.15 in seg4. 

Plasma no disruption this time. Current rise is faster, got to 570kA 
at 0.1sec this time. Still no cascades. 

give up on cascades. Go back to shot#14


Jun 20 2006 03:17:26:707PM1060620023Steve Wolfe
Shot#23: Reload shot 1060620014 (120ms He3 puff, No Ip gain in seg1,...)
Note: PCS trapped the cursor in the all_v screen and I had to blow
away the PCS from another ws and restart before this shot. 

plasma disrupts at 0.5sec, PF breaker pulled after. 
J had a little trouble early in the RF pulse. 

Next: change field from 5.4 to 5.35 

Jun 20 2006 03:30:48:730PM1060620024Steve Wolfe
Shot#24: Change TF Cur from -150000 to -148600 (seg1 and seg4)
Plasma disrupts at 0.5sec. 

Next: Delay Ip gain switch from 0.5 to 0.7sec (I did this earlier,
but it got lost). 


Jun 20 2006 03:45:20:970PM1060620025Steve Wolfe
Shot#25: Delay Ip gain switch from 0.5 to 0.7sec (I did this earlier,
but it got lost).  Probably not related to the disruption, which was 
actually a bit before .5sec. 
No other PCS changes. RF is changing phase. 

Disrupted again, around 0.38sec. ECE gate valve was closed from the
last disruption. J faulted early on this one. 

next: drop PG4 by 1msec


Jun 20 2006 03:58:06:587PM1060620026Steve Wolfe
Shot#26:PG4 from 22 to 21msec, post-disruption. 

Disrupts at 0.45sec, breaker pulled after. 
Wide 2 shows lots of injections and glowing things. 

Next: Increase PG2 to 150msec

Jun 20 2006 04:10:44:413PM1060620027Steve Wolfe
Shot#27:Increase PG2 from 120 to 150msec
Disrupts at .53sec. We're clearly overheating something.

Next: drop PG4 again, post-disrupt

Jun 20 2006 04:29:34:717PM1060620028Steve Wolfe
Shot#28: PG4 from 21 to 20msec
plasma disrupts at .43sec
That one had some early runaways. 



Jun 20 2006 04:42:25:260PM1060620029Steve Wolfe
Shot#29: No pcs changes. These disruptions seem to be from
major injections associated with the high RF power into these
low density targets. The wide 2 view looks like the J antenna 
lower corner on the H-port side is one of the sources, but also 
injections are coming from all around the machine. 

Plasma with lots of early runaways. Looks like an injection or 
something scraping at 20 to 25msec, not a bounce, but the
current drops and then rises again. Xrays saturating the detector. 

next: increase pg4, just to do something



Jun 20 2006 04:56:03:367PM1060620030Steve Wolfe
Shot#30: PG4 from 20 to 22msec; probably going to fizzle
Very short plasma, .17sec, never sawtooths. 
Startup looks clean, but Prad just goes through the roof. 

One more try, no PCS changes. 



Jun 20 2006 05:08:20:887PM1060620031Steve Wolfe
Shot#31: no PCS changes, still trying to get the heating phase case.
plasma to .4sec or so, some early runaways but not as bad as 29.
J stays on until about 0.3sec, then J3 has an overload fault. 

End of Run.  



Engineering Operator Comments
ShotTimeTypeStatusComment
109:03:10:520AMPlasmaOk
209:32:34:060AMPlasmaOk
309:50:26:613AMPlasmaOk
410:06:21:713AMPlasmaBadOH1 Type 1 Flt
510:22:44:660AMPlasmaOk
610:35:50:257AMPlasmaOk
710:52:35:327AMPlasmaOk
811:08:43:270AMPlasmaOk
911:24:02:760AMTestBad
1011:47:22:110AMPlasmaOk
1112:00:08:273PMPlasmaOk
1212:13:10:173PMPlasmaOk
1312:25:46:323PMPlasmaOk
1412:40:52:997PMPlasmaOk
1512:56:20:123PMPlasmaOk
1601:09:31:980PMPlasmaOk
1701:23:00:973PMPlasmaBadOH1 fault opened breaker.
1801:41:05:223PMPlasmaOk
1901:54:40:220PMPlasmaOk
2002:07:09:643PMPlasmaBadOH2U (Misc. Fault)
2102:33:39:943PMPlasmaOkOH2 type 3 misc fault
2202:52:00:437PMPlasmaOk
2303:11:00:907PMPlasmaOkOH1 self power circuit fired
2403:25:47:760PMPlasmaOk
2503:38:23:970PMPlasmaOk
2603:51:00:410PMPlasmaOkOH1 self powered circuit fired
2704:04:54:510PMPlasmaOk
2804:21:09:633PMPlasmaOkOH1 self powered circuit fired
2904:36:40:377PMPlasmaOk
3004:49:29:003PMPlasmaOk
3105:01:58:820PMPlasmaOkOH1 self powered circuit fired