Alcator C-Mod Run 1051101 Information

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Miniproposals
Miniproposal:298a
Date Filed: 5/20/2002
Title:C-Mod Plasma Startup
First Author:Jim Irby
Session Leader:Steve Wolfe (shots 1-26)

Operators
Session leader(s):Steve Wolfe
Physics operator(s):Steve Wolfe,Ian Hutchinson
Engineering operator(s):Bill Cochran,Bill Parkin

Engineering Operator Run Comment
C-Mod Plasma Startup

Session Leader Plans

Physics Operators Plans
Entered: Oct 31 2005 04:49:09:830PM
Author: Steve Wolfe
Engineering setup for Tuesday 1-Nov-2005

MP298A Plasma startup

Session leader: wolfe
Physics operator: Hutchinson (wolfe for the first few shots)

Overnight ECDC in D2, and bake at 60 C.

Run begins at 09:00 (assuming alternator is ready) and ends at 17:00

Power systems as on 1051031027 (1.0 MA fiducial, 5.4 T, lower single null)

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  Hybrid DISABLED (PG1)
  leave B-side upper     as is           Hybrid DISABLED (PG2)
   fill B-main (C-side)  with 40 psi D2  Hybrid enabled  (PG3)
  leave NINJA            as is           Leave DISABLED

Enable the following gate valves and shutters, assuming no vacuum problems:
  ECE, VUV, Z-bolo shutters

Torvac setup: Gate valves open

No between-shot boronization.

Important Diagnostics: magnetics, standard impurity spectroscopy

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ICRF Setup: No RF required today, although it can be used at will.

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Run plan: Start from wherever Bob left off on Monday, and try to get 
reproducible plasmas. Most likely, we'll want to drop the current program 
down from 1MA (on 1051031027) to 600kA or so, and probably reduce the 
early gas and nl04 program, in order to get full length plasmas.





Session Leader Summaries
Entered: Nov 1 2005 05:13:52:593PM
Author: Steve Wolfe
Pretty good progress was made today toward the goal of 
getting back on the air after the manned access vent. 

The first shot of the day was a full length 800kA plasma. 
Ian did quite a lot of tweaking at the startup, mostly 
field tuning. He was successful in getting rid of the runaways
for most of the later discharges, but startup reliability 
was still pretty spotty. 

The BP16_DE loop, which had started to get flakey yesterday,
failed around shot 6 and had to be replaced with the JK loop. 
This means old shots will need to have the mag predictors 
recalculated, although the difference in BTOR pickup is not
very large, so it shouldn't matter much. 

The H/D ratio was not bad for this stage of the operation, below 
0.4 in flattop for most of the 800ka shots. 
After the first couple of plasmas the 
density was pretty well controlled. There were some dithery 
ohmic h-modes on some of the later 800kA shots, e.g. #20.

The current was raised from 800kA to 1.0MA on shot 23 and to 1.2MA
on shot#26. H/D was up somewhat at the higher currents. 
We ended up with 11 full length plasmas.

The run was interupted for about an hour in the morning 
for an alternator control problem. We also took several 
alternator excitation tests in order to try to track down
some ghosts. Shots were also lost due to some PLC and 
computer problems (no gas, no 13.8 power supplies, dispatcher
seg fault in INIT,...). The usual shakedown problems, I suppose. 
We are also missing some diagnostics, including Z-meter, Thomson, GPC1, etc.
Joe and Yuri did get the pulsed gas drive signals back during 
the long delay, and Joe replaced the dead bp16_ghk signal with 
bp19_ghk, which had not been going to an integrator; as noted
above, we also replaced the BP16_DE with BP16_JK into DPCS. 



Physics Operator Summaries
Entered: Nov 1 2005 05:10:28:080PM
Author: Ian Hutchinson
Summary
_______

This day had its fair share of problems with many different systems,
but predominantly computers. A magnetics sensor had to be swapped out
of pcs. Various tests on alternator and investigations of unusual
rumbling noises delayed us for major periods.

Plasma startup reliability was close to 50%. A reload of the magic shot
1050525002 showed that even with identical settings we were not
getting anything like the same field evolutions as we used to
do. Therefore several different tweaks were used to attempt to
reproduce particularly the time evolution of Bz. EF3 Voltage, and EF4
current are serious knobs, together with Rcur offset in segment 1.

We found that a Bz evolution like the magic shot is good for
breakdown, but that at present Bz is not reliable shot to shot. It
bounces up and down by about 1 mT, shot to shot, which is enough to
spoil the startup reliability. The startup for shots 23 onward seems
a decent place to start.

The plasma now seems quite clean. Radiation is low, not many
injections. H/D down to about 0.35. Plasma up to 1.2MA has been run.
No disruptions today. Maybe we need some!


Scorecard
_________


Shot,Duration(s),Ipmax(MA),Result Shot,Duration(s),Ipmax,Result
| 01 1.924 0.805 Plasma | 2 No Ip |
| 03 0.000 0.027 Fizzle | 04 0.000 0.024 Fizzle |
| 05 0.000 0.002 Dud | 06 0.000 0.025 Fizzle |
| 07 1.981 0.820 Plasma | 8 No Ip |
| 09 1.978 0.823 Plasma | 10 1.973 0.823 Plasma |
| 11 0.000 0.024 Fizzle | 12 0.000 0.024 Fizzle |
| 13 0.000 0.023 Fizzle | 14 0.000 0.023 Fizzle |
| 15 1.973 0.824 Plasma | 16 1.772 0.821 Plasma |
| 17 0.000 0.026 Fizzle | 18 1.977 0.819 Plasma |
| 19 0.000 0.025 Fizzle | 20 1.973 0.823 Plasma |
| 21 0.000 0.026 Fizzle | 22 0.000 0.025 Fizzle |
| 23 1.947 1.006 Plasma | 24 0.000 0.009 Dud |
| 25 1.975 1.002 Plasma | 26 1.941 1.195 Plasma |

Date 1051101: 26 shots. 11 plasmas. 11 fizzles. 2 duds. 2 System Error.
(Plasma = Ip gt 50.0 kA Dud = H_alpha lt 0.40 V)
Total plasma duration: 21.41 s (exceeding -80 kA)


Session Leader Comments
Nov 1 2005 09:42:35:267AM1051101002Steve Wolfe
Shot#2: alternator excitation test only
with all breakers open. 

Nov 1 2005 09:52:49:267AM1051101003Steve Wolfe
Shot#3: Another plasma try, no changes by physop
Fizzle. 

Nov 1 2005 10:03:45:203AM1051101004Steve Wolfe
Shot#4: Dud

Nov 1 2005 10:55:36:877AM1051101004Steve Wolfe
After shot#4:
We have at least an hour delay for the alternator.  

Joe and Yuri found and installed another set of cables 
in the PHA INCAA, on channels 5 and 13-16, which seem to 
correspond to the correct drive signals, according
to the info in the tree. We'll see. 

Nov 1 2005 12:05:58:737PM1051101005Steve Wolfe
Shot 5: Alternator excitation test
Air switch closed, breakers open

Held in check and then ramped excitation down
before going to pulse. DPCS timed out of course.

Nov 1 2005 12:21:47:407PM1051101006Steve Wolfe
Shot 6: Plasma attempt.
Dud. Well, at least we got the gas valve signals back.
BP16_DE is still bad. Will change to the JK loop.



Nov 1 2005 12:54:47:970PM1051101007Steve Wolfe
Shot#7: plasma full length. When it works it works.
Bad runaways again. Some bounces very early.
Actually puffing gas to maintain density. 
H/D gets down to .35 by EOF. Not bad for nl04~0.5e20



Nov 1 2005 01:04:46:390PM1051101007Steve Wolfe
Shot#8: Raise nl04 target
DPCS_INIT shows as hung in INIT, but the log file 
indicates completion in 33seconds
   MSG_PREFIX      STRING    '% '
       33.018190 seconds in dpcs_init
Finished DPCS_INIT Tue Nov  1 12:55:47 2005

and the logbook shows green. 
I don't think it's really a dpcs problem. 

Took a no power shot. No gas puff




Nov 1 2005 01:26:14:640PM1051101009Steve Wolfe
Shot#9: Raise nl04 target
Problem on shot 8 seems to have been a dispatcher
glitch. 
plasma full length. Bad runaways again. 

next shot: try to get rid of runaways.


Nov 1 2005 01:35:44:440PM1051101010Steve Wolfe
Shot#10:  trying to get rid of runaways.
plasma full length. Still some runaways but better.
Startup looks worse, a little later and more of a bounce.


Nov 1 2005 01:46:28:720PM1051101011Steve Wolfe
Shot#11: Just keep slogging along. 
Dud. 


Nov 1 2005 01:58:07:343PM1051101012Steve Wolfe
Shot#12: Another dud. 


Nov 1 2005 02:11:24:627PM1051101013Steve Wolfe
Shot#13: Another dud. 


Nov 1 2005 02:23:51:203PM1051101014Steve Wolfe
Shot#14: Fizzle.  


Nov 1 2005 02:47:55:203PM1051101015Steve Wolfe
Shot#15: plasma, full length. Runaways are gone, too. 
 


Nov 1 2005 02:53:01:033PM1051101016Steve Wolfe
Shot#16: plasma to 1.75sec; 
density similar, hard xrays still absent
startup later, not as nice


Nov 1 2005 03:04:30:593PM1051101017Steve Wolfe
Shot#17: fizzle


Nov 1 2005 03:19:47:140PM1051101018Steve Wolfe
Shot#18: plasma full length



Nov 1 2005 03:30:26:283PM1051101019Steve Wolfe
Shot#19: fizzle



Nov 1 2005 03:58:24:157PM1051101021Steve Wolfe
Shot#20: fizzle
next shot: raise current to 1MA (and hopefully also
fix the fizzle)

Nov 1 2005 04:34:36:453PM1051101022Steve Wolfe
Shot#22: raise current to 1MA 
dud. No gas puff; PLC problem?


Nov 1 2005 04:34:10:750PM1051101023Steve Wolfe
Shot#23: raise current to 1MA 
plasma full length. One minor injection
at EOF. 


Nov 1 2005 04:39:17:250PM1051101024Steve Wolfe
Shot#24: Hardly any power supplies; ack failure?
Only the TMX's and gas went. 


Nov 1 2005 04:58:41:547PM1051101025Steve Wolfe
Shot#25: plasma full length. 
Pat's voice did not come up in check (no countdown), 
but we ran anyway and it worked. 
H/D is up above 0.4 on this one.

next shot: go for 1.2MA (why not?)

Nov 1 2005 05:11:24:267PM1051101026Steve Wolfe
Shot#26: plasma full length, 1.2MA 
Density is up a little, with the gas turned off. 
H/D between 0.45 and 0.5 in flattop.

Physics Operator Comments
Nov 1 2005 07:56:16:547AMSteve WolfeSetting up for first shot. Bob's notes say that
he changed the target to 800kA and .6e20. Bring up
PCS and check; it looks like he loaded it.
Change title of seg2 to match.

Pg4 is at 18msec, probably a little low for first shot
of the day. Increase to 21msec.
Br0 is at 0, ef4 at -1325; leave them like that.

Load at 1-Nov-2005 07:55:47.00
Open tree /home/wolfe/pcs_scratch -1
Open tree done

Ready for first shot.
Nov 1 2005 08:47:41:377AMSteve WolfeSetting up for first shot. Bob's notes say that
he changed the target to 800kA and .6e20. Bring up
PCS and check; it looks like he loaded it.
Change title of seg2 to match.

Pg4 is at 18msec, probably a little low for first shot
of the day. Increase to 21msec.
Br0 is at 0, ef4 at -1325; leave them like that.

Load at 1-Nov-2005 07:55:47.00
Open tree /home/wolfe/pcs_scratch -1
Open tree done

Ready for first shot.
Nov 1 2005 09:15:42:533AM1051101001Steve Wolfe
Shot#1: Try for plasma. Later we'll try to isolate
the low-frequency noise we heard in the power room 
yesterday.

Plasma, full length. Early runaways 
No magnetics data. Can't contact Josh or Tom by phone!

Still no data from the gas valve drives, despite the 
fact that Joe and Yuri found and replaced the cables 
yesterday evening.



Nov 1 2005 09:38:17:720AM1051101001Ian HutchinsonShot 1 set up by Wolfe ran full length. Well controlled density 0.8e20.
However, this is plainly fuelling off the walls since the nl04 is set at .6e20.
Some data problems mean that traces are missing for this shot.
Nov 1 2005 09:50:59:923AM1051101002Ian HutchinsonPower systems tests to listen for vibrations.
Nov 1 2005 10:03:25:330AM1051101003Ian HutchinsonFizzle.

EF4 to -1315 from -1325A
Nov 1 2005 12:27:01:593PM1051101004Ian HutchinsonDud. This shot is now within 5A of the standard 1050525002 PCS settings.
Startup currents show OH2L -239A as the only significant difference.

Load segment 1 from 1050525002. Load.
Nov 1 2005 12:40:04:093PM1051101006Ian HutchinsonDud with standard shot.

EF3 Voltage to 2000V from 2650 at -1ms. This is supposed to moderate the upswing of Bz.

For next shot we are replacing bp16DE with bp16jk. Wolfe changed the configuration.
I called all predictors for the magnetics based wires, in segments 2 and 3.
Also I copy segment 2 to segments 3 and 4 to ensure that we don't have incorrect
settings.

Load Clean.

Nov 1 2005 12:54:32:640PM1051101007Ian HutchinsonPlasma to ramp-down. Density is under control till 1s. C-side gas puff is on till the nl04 is programmed down.

Raise nl04 to 0.7e20.
Nov 1 2005 01:19:52:517PM1051101008Ian HutchinsonNo plasma shot because of dpcs problem.

Drag OH2U,L traces 1 ms later in segment 1.
Nov 1 2005 01:34:42:000PM1051101009Ian HutchinsonPlasma to rampdown.

EF3 Voltage to 2200V at -1ms.
Nov 1 2005 01:48:05:750PM1051101010Ian HutchinsonPlasma to rampdown. Breakdown at 7ms

EF3 V to 2300.
Nov 1 2005 01:55:43:547PM1051101011Ian HutchinsonDud. Bz too high at 5ms.

EF3V to 2000 at -1ms from 2400 to 2500 at 5ms.
Nov 1 2005 02:12:27:470PM1051101013Ian HutchinsonDud. Bz still too positive. It has been drifting up prior to commutation.

EF4 Current to -1320A from -1310.
Nov 1 2005 02:14:32:203PM1051101013Ian HutchinsonDud. Bz does not look too bad.

Raise fill puff to 26ms from 21.
EF4 Current to -1325A
Nov 1 2005 02:38:50:987PM1051101014Ian HutchinsonFizzle.

EF4 current to -1330A.
EF3 Voltage to 2300 at -1ms.
Fill puff to 21ms.
Nov 1 2005 02:52:52:610PM1051101015Ian HutchinsonPlasma to rampdown.

Add subsistence V to PG3 during flat top.
Nov 1 2005 02:57:23:547PM1051101016Ian HutchinsonPlasma till 1.75s. Bz dribbles down a bit. Breakdown at 8ms.

nl04 to .7e20 at .25s
EF4 current to -1325
Nov 1 2005 03:10:51:953PM1051101017Ian HutchinsonFizzle.

EF4 to -1330A.
Move OH2 timing 1ms later (more).
Nov 1 2005 03:30:15:377PM1051101018Ian HutchinsonPlasma till rampdown.

Move EF1 programing 1ms earlier.
Nov 1 2005 03:43:11:767PM1051101019Ian HutchinsonFizzle. Breakdown at 15ms! Bz too low. The target is small. I did not do that.

EF4 to -1325A.
Nov 1 2005 03:52:12:377PM1051101020Ian HutchinsonPlasma till rampdown.

Segment 1 Rcur offset to 1600 from 1500.
Nov 1 2005 04:11:30:877PM1051101021Ian HutchinsonFizzle

Ip to 1 MA.
Nov 1 2005 04:24:11:127PM1051101022Ian HutchinsonDud. There is a big bounce on the Bz which had settings exactly the same as last time. However, the main problem was no fill puff.
Nov 1 2005 04:37:38:890PM1051101023Ian HutchinsonPlasma till rampdown (after no changes).
Nov 1 2005 04:50:56:250PM1051101024Ian HutchinsonNo power supplies.
Nov 1 2005 05:03:58:500PM1051101025Ian HutchinsonPlasma till rampdown. This shot had a rather loud rumble.

Ip to 1.2 MA.

Engineering Operator Comments
ShotTimeTypeStatusComment
109:02:52:533AMPlasmaOk
309:48:47:970AMPlasmaOk
410:01:52:657AMPlasmaOk
511:57:09:110AMTestOkAlternator Excitation Test
612:14:06:360PMPlasmaOk
712:43:14:237PMPlasmaOk
901:18:27:547PMPlasmaOk
1001:31:08:080PMPlasmaOk
1101:43:53:453PMPlasmaOk
1201:56:30:750PMPlasmaOk
1302:09:08:860PMPlasmaOk
1402:21:42:657PMPlasmaOk
1502:35:03:220PMPlasmaOk
1602:48:20:063PMPlasmaOk
1703:01:44:140PMPlasmaOk
1803:14:52:237PMPlasmaOk
1903:28:10:593PMPlasmaOk
2003:41:10:940PMPlasmaOk
2103:56:02:127PMPlasmaOk
2204:09:07:720PMPlasmaOk
2304:22:09:453PMPlasmaOk
2404:35:19:063PMPlasmaBadNo TF, OH's, EF1,3 or 4
2504:48:26:657PMPlasmaOk
2605:01:52:220PMPlasmaOk