Alcator C-Mod Run 1020702 Information

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Miniproposals
Miniproposal:298a
Date Filed: 5/20/2002
Title:C-Mod Plasma Startup
First Author:Jim Irby
Session Leader:Jim Irby (shots 1-24)

Operators
Session leader(s):Jim Irby
Physics operator(s):Ian Hutchinson
Engineering operator(s):Ed Fitzgerald,Gary Dekow,Bill Parkin

Engineering Operator Run Comment
Continuation of MP 298A; PO:Hutch; SL:Irby; EO:Dekow/Parkin/Fitzgerald

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:29:193PM
Author: To Be Determined
Run Summary for July 2, 20002: Plasma Conditioning

EO: Dekow/Parkin
PO: Hutch
Sl: Irby

We only obtained 7 plasmas today. All the plasmas were lower null discharges,
though the density is uncertain because of the failure of the TCI CO2
detector. From the visible bremsstralung signal a density of 7e19/m^2 seems
resonable. H/D ran 10 to 12% on all the shots. This level of hydrogen is
an improvement from yesterday once the lower density is taken into account.
We have to consider whether or not H/D is low enough for boronization, or if
we should run one more day next Tuesday.

The LPI came back into operation today and even shot multiple pellets
on shot 22.

Duds 10 --- PLC fault --- no gas
Fizzles 02,04,06,07,09,11,12,14,15,16,17,18,19,20,22
Plasmas 01,05,08,13,21,23,24
Test 03

Physics Operator Summaries
Entered: Jul 7 2004 04:37:15:257PM
Author: To Be Determined
Physop Summary 1020702
Start Up MP 298a

More plasma conditioning.


Summary
_______

We had many fizzles today as we played with trying to get a better
startup. By the end of the day, startup was obtained with the rcur
feedback moved back to 2ms and its gain up by a factor of 2. This has
the advantage of being somewhat under feedback control during the
current initiation. However, the power supply responses are slow
enough that it is not yet clear whether this will give a much more
reliable startup. Shots 23 and 24 were two in a row good current rise
with the new configuration.

H/D was reliably between 10 and 15%, in plasmas that were given a
constant gas puff which totalled to about 10 torr-l for a total 1.5s
shot. No density measurements were available.

Scorecard:
_________

Shot,Duration(s),Ipmax(MA) Shot,Duration(s),Ipmax
1 1.930 0.792 2 0.000 0.031
3 0.000 0.018 4 0.000 0.037
5 1.939 0.792 6 0.000 0.042
7 0.000 0.039 8 1.914 0.786
9 0.000 0.037 10 0.000 0.019
11 0.000 0.039 12 0.000 0.034
13 1.922 0.786 14 0.000 0.039
15 0.000 0.034 16 0.000 0.044
17 0.000 0.039 18 0.000 0.042
19 0.000 0.042 20 0.000 0.044
21 1.915 0.789 22 0.000 0.039
23 1.913 0.786 24 1.924 0.789

Finished summary for 1020702 Total of 24 shots.
24 shots. 7 plasmas. 15 fizzles. 2 duds.
Fizzle = gt 27.0 lt 50kA.



Details:
________
Entry display output on Tue Jul 2 17:11:03 2002


----------------------------------------------------------------------------
1020702xxx hutch PHYSICS_OPERATOR Jul 2 2002 8:50:05:936AM
. . . . . . . . . . . . . . . . . . . .
Start Up MP 298a

More plasma conditioning.

Interferometer is not working so we are going to have to use z-meter control.
However, Wolfe reports that the z-meter input to the hybrid was not working yesterday.
Therefore, at least to start with, we will have to go with open-loop puff programming.

Discovered that @cmod$models:[hybrid]pcs seems to leave idl in tek mode when run from ssh into spanna
this might be some strangeness with my setup. Have to do set_plot,'X', before pcs.

Cold start
rtnode -- data loaded, A matrix responds
rtnode -- data loaded, M matrix responds
rtnode -- data loaded, PID matrix responds
----------------------------------------------------------------------------
1020702xxx hutch PHYSICS_OPERATOR Jul 2 2002 9:08:38:210AM
. . . . . . . . . . . . . . . . . . . .
Set nl_04 gain to zero in segment 2.

Go into pulse gas 3 and set to 30. This is somewhat lower than the roughly 50 value
that was obtained by feedback on 1020701023,

There is a bug in pcs that prevents middle button from copying into all Vs panel.
----------------------------------------------------------------------------
1020702001 hutch PHYSICS_OPERATOR Jul 2 2002 9:34:28:696AM
. . . . . . . . . . . . . . . . . . . .
Plasma. Fine shot. 10 torr-l of gas puffed.

RF power on j-port ramped to .6MW. Shows pickup on a lot of signals
Ratiomatic, 2pi foil,

H/D 10%.
----------------------------------------------------------------------------
1020702002 hutch PHYSICS_OPERATOR Jul 2 2002 10:57:51:150AM
. . . . . . . . . . . . . . . . . . . .
Fizzle.

EF4 to -1340 from -1350A
Br offset to .002 from .0015
----------------------------------------------------------------------------
1020702003 hutch PHYSICS_OPERATOR Jul 2 2002 11:02:35:290AM
. . . . . . . . . . . . . . . . . . . .
Test pulse on pcl control

We have been chasing the problem that caused the OHs to rail on shot 2.
The A-out looked consistent but the Ms are totally unusual immediately after the switch to segment 2.
I conclude that there is a problem with M at the segment switch. However, we have not isolated it.

Load clean and then did a cold start.
Try a shot.
----------------------------------------------------------------------------
1020702004 hutch PHYSICS_OPERATOR Jul 2 2002 11:18:42:916AM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Power supplies behaved normally.

EF4 to -1330 from -1340A Load clean.
----------------------------------------------------------------------------
1020702005 hutch PHYSICS_OPERATOR Jul 2 2002 11:33:24:303AM
. . . . . . . . . . . . . . . . . . . .
Plasma.
13% H/D. Pellet fired into ramp-down.

Repeat
----------------------------------------------------------------------------
1020702006 hutch PHYSICS_OPERATOR Jul 2 2002 11:52:07:770AM
. . . . . . . . . . . . . . . . . . . .
Fizzle. On inside, but not obvious why.

OH1V to 150 @ 8ms from 200,
to 150 @ 3ms from 120
Load clean
5min of ECDC.
----------------------------------------------------------------------------
1020702007 hutch PHYSICS_OPERATOR Jul 2 2002 12:09:42:383PM
. . . . . . . . . . . . . . . . . . . .
Fizzle.

OH1V to 190 @ 3ms from 150.
5 min ECDC.
----------------------------------------------------------------------------
1020702008 hutch PHYSICS_OPERATOR Jul 2 2002 12:30:20:230PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

OH1V to 0V @ 0ms from -99.
----------------------------------------------------------------------------
1020702009 hutch PHYSICS_OPERATOR Jul 2 2002 12:50:39:400PM
. . . . . . . . . . . . . . . . . . . .
Fizzle.

EF4 to -1320 from -1330A.
----------------------------------------------------------------------------
1020702010 hutch PHYSICS_OPERATOR Jul 2 2002 1:10:10:540PM
. . . . . . . . . . . . . . . . . . . .
Dud. No gas. M-out gave the signal. Valves did not respond.

Repeat.
----------------------------------------------------------------------------
1020702011 hutch PHYSICS_OPERATOR Jul 2 2002 1:29:07:770PM
. . . . . . . . . . . . . . . . . . . .
Plasma

Move rcur feedback switches to 3ms (P) and 5ms (D) and make P=4 (was 2).
----------------------------------------------------------------------------
1020702012 hutch PHYSICS_OPERATOR Jul 2 2002 1:49:01:626PM
. . . . . . . . . . . . . . . . . . . .
Fizzle.
It is clear that it knew about the earlier feedback, showing that the feedback does do something.
Obviously, though, there are enough offsets in rcur that we are guessing with the early feedback.
Wolfe reports that the 6500 offset was chosen larger to make the Bz ramp faster.

Load from shot 8 Load/clean.
----------------------------------------------------------------------------
1020702013 hutch PHYSICS_OPERATOR Jul 2 2002 2:04:10:236PM
. . . . . . . . . . . . . . . . . . . .
Plasma. H/D 12%.

Repeat

----------------------------------------------------------------------------
1020702014 hutch PHYSICS_OPERATOR Jul 2 2002 2:22:33:840PM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Moves in.

Rcur offset to 2000.
P gain start to 2ms. (P=2).
Load.
----------------------------------------------------------------------------
1020702015 hutch PHYSICS_OPERATOR Jul 2 2002 2:43:31:293PM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Bounced.

EF4 to -1310A from -1330
RCUR offset to 0.
Load/clean
----------------------------------------------------------------------------
1020702016 hutch PHYSICS_OPERATOR Jul 2 2002 3:02:29:476PM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Got to nearly 50kA but with probably too little dBdt.

Redraw the rcur waveform a bit more sensibly.
OHV @ 7ms to 150 from 200V, to 100V at 10ms. Load.
----------------------------------------------------------------------------
1020702017 hutch PHYSICS_OPERATOR Jul 2 2002 3:20:02:780PM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Rdrawing the trace had much more effect that I expected. Bounced outside.

rcur Offset 2800, gain to 4 (from 2).
OH1V to 100 from 150 at 10ms.
----------------------------------------------------------------------------
1020702018 hutch PHYSICS_OPERATOR Jul 2 2002 3:36:00:410PM
. . . . . . . . . . . . . . . . . . . .
Fizzle.

D start to 7ms from 10.
OH1 V to 100v from 150 at 7 and 8ms. To 150 from 200V at 5ms.
----------------------------------------------------------------------------
1020702019 hutch PHYSICS_OPERATOR Jul 2 2002 3:53:34:290PM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Nearly 50kA. Still bouncing on outside. Didnt get much effect from my changes.

OH1V to 100V at 3 and 5ms.
----------------------------------------------------------------------------
1020702020 hutch PHYSICS_OPERATOR Jul 2 2002 4:11:02:330PM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Died inside.


Add rcur drawn point at 1ms .68m. Load
----------------------------------------------------------------------------
1020702021 hutch PHYSICS_OPERATOR Jul 2 2002 4:26:49:110PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Monster bounce. Mostly lucked out. But this shows that the Bz ramp rate it still a lot too small.

rcur drawn to .63 at 10ms.
EF3 voltage to 2500 at 10 and 12 ms.
----------------------------------------------------------------------------
1020702022 hutch PHYSICS_OPERATOR Jul 2 2002 4:43:55:790PM
. . . . . . . . . . . . . . . . . . . .
Fizzle. 40kA.

Br offset to 1.5mT from 2.
----------------------------------------------------------------------------
1020702023 hutch PHYSICS_OPERATOR Jul 2 2002 5:03:45:896PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Bz fluctuated back up to its proper place.

Repeat
----------------------------------------------------------------------------
1020702024 hutch PHYSICS_OPERATOR Jul 2 2002 5:03:52:430PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

Session Leader Comments
Jul 2 2002 09:44:35:870AM1020702001Jim IrbyPlasma

H/D at 11%

Jul 2 2002 09:44:49:620AM1020702002Jim IrbyFizzle
Jul 2 2002 11:10:49:110AM1020702003Jim IrbyOH Test at 10kA to check hybrid
Jul 2 2002 11:11:20:690AM1020702004Jim IrbyPlasma Attempt

OHL looks okay but had a fizzle
Jul 2 2002 11:30:41:577AM1020702005Jim IrbyPlasma to rampdown

H/D 14% and flat
Jul 2 2002 12:01:01:577PM1020702006Jim Irbyrepeat --- see what h/d does
5 minutes ecdc before shot (2e-4 torr)
fizzle
Jul 2 2002 12:00:33:247PM1020702007Jim Irby5 minutes ecdc before shot (2e-4 torr)
fizzle
Jul 2 2002 12:24:04:413PM1020702008Jim Irby5 minutes ecdc
plasma
H/D 12%

CII at .002 level
Jul 2 2002 12:39:57:337PM1020702009Jim IrbyFizzle
Jul 2 2002 12:56:49:920PM1020702010Jim IrbyNo gas ----
Jul 2 2002 01:11:07:713PM1020702011Jim Irbyfizzle
Jul 2 2002 01:32:05:170PM1020702012Jim Irbyfizzle
Jul 2 2002 02:05:02:287PM1020702013Jim IrbyReload of shot 8
Plasma

h/d 11% at 1.0 s
Jul 2 2002 02:11:20:197PM1020702014Jim Irbyfizzle
Jul 2 2002 02:50:58:770PM1020702014Jim Irbyfizzle
Jul 2 2002 02:51:23:693PM1020702016Jim Irbyfizzle
Jul 2 2002 03:17:21:523PM1020702017Jim Irbyfizzle
Jul 2 2002 04:09:59:153PM1020702018Jim Irbyfizzle --- 45 kA


Jul 2 2002 04:19:22:560PM1020702021Jim Irbyplasma at last
had a Li pellet
400 kW of rf from J-port

h/d 10% at 1 s


Jul 2 2002 05:05:54:480PM1020702023Jim IrbyPlasma
Earl fires 3 pellets w/o disruption
h/d 10-11%
Jul 2 2002 05:09:13:803PM1020702024Jim IrbyPlasma
H/D 12% at 1.0

Physics Operator Comments
Jul 2 2002 08:50:05:937AMIan HutchinsonStart Up MP 298a

More plasma conditioning.

Interferometer is not working so we are going to have to use z-meter control.
However, Wolfe reports that the z-meter input to the hybrid was not working yesterday.
Therefore, at least to start with, we will have to go with open-loop puff programming.

Discovered that @cmod$models:[hybrid]pcs seems to leave idl in tek mode when run from ssh into spanna
this might be some strangeness with my setup. Have to do set_plot,'X', before pcs.

Cold start
rtnode -- data loaded, A matrix responds
rtnode -- data loaded, M matrix responds
rtnode -- data loaded, PID matrix responds
Jul 2 2002 09:08:38:210AMIan HutchinsonSet nl_04 gain to zero in segment 2.

Go into pulse gas 3 and set to 30. This is somewhat lower than the roughly 50 value
that was obtained by feedback on 1020701023,

There is a bug in pcs that prevents middle button from copying into all Vs panel.
Jul 2 2002 09:34:28:697AM1020702001Ian HutchinsonPlasma. Fine shot. 10 torr-l of gas puffed.

RF power on j-port ramped to .6MW. Shows pickup on a lot of signals
Ratiomatic, 2pi foil,

H/D 10%.
Jul 2 2002 10:57:51:150AM1020702002Ian HutchinsonFizzle.

EF4 to -1340 from -1350A
Br offset to .002 from .0015
Jul 2 2002 11:02:35:290AM1020702003Ian HutchinsonTest pulse on pcl control

We have been chasing the problem that caused the OHs to rail on shot 2.
The A-out looked consistent but the Ms are totally unusual immediately after the switch to segment 2.
I conclude that there is a problem with M at the segment switch. However, we have not isolated it.

Load clean and then did a cold start.
Try a shot.
Jul 2 2002 11:18:42:917AM1020702004Ian HutchinsonFizzle. Power supplies behaved normally.

EF4 to -1330 from -1340A Load clean.
Jul 2 2002 11:33:24:303AM1020702005Ian HutchinsonPlasma.
13% H/D. Pellet fired into ramp-down.

Repeat
Jul 2 2002 11:52:07:770AM1020702006Ian HutchinsonFizzle. On inside, but not obvious why.

OH1V to 150 @ 8ms from 200,
to 150 @ 3ms from 120
Load clean
5min of ECDC.
Jul 2 2002 12:09:42:383PM1020702007Ian HutchinsonFizzle.

OH1V to 190 @ 3ms from 150.
5 min ECDC.
Jul 2 2002 12:30:20:230PM1020702008Ian HutchinsonPlasma.

OH1V to 0V @ 0ms from -99.
Jul 2 2002 12:50:39:400PM1020702009Ian HutchinsonFizzle.

EF4 to -1320 from -1330A.
Jul 2 2002 01:10:10:540PM1020702010Ian HutchinsonDud. No gas. M-out gave the signal. Valves did not respond.

Repeat.
Jul 2 2002 01:29:07:770PM1020702011Ian HutchinsonPlasma

Move rcur feedback switches to 3ms (P) and 5ms (D) and make P=4 (was 2).
Jul 2 2002 01:49:01:627PM1020702012Ian HutchinsonFizzle.
It is clear that it knew about the earlier feedback, showing that the feedback does do something.
Obviously, though, there are enough offsets in rcur that we are guessing with the early feedback.
Wolfe reports that the 6500 offset was chosen larger to make the Bz ramp faster.

Load from shot 8 Load/clean.
Jul 2 2002 02:04:10:237PM1020702013Ian HutchinsonPlasma. H/D 12%.

Repeat

Jul 2 2002 02:22:33:840PM1020702014Ian HutchinsonFizzle. Moves in.

Rcur offset to 2000.
P gain start to 2ms. (P=2).
Load.
Jul 2 2002 02:43:31:293PM1020702015Ian HutchinsonFizzle. Bounced.

EF4 to -1310A from -1330
RCUR offset to 0.
Load/clean
Jul 2 2002 03:02:29:477PM1020702016Ian HutchinsonFizzle. Got to nearly 50kA but with probably too little dBdt.

Redraw the rcur waveform a bit more sensibly.
OHV @ 7ms to 150 from 200V, to 100V at 10ms. Load.
Jul 2 2002 03:20:02:780PM1020702017Ian HutchinsonFizzle. Rdrawing the trace had much more effect that I expected. Bounced outside.

rcur Offset 2800, gain to 4 (from 2).
OH1V to 100 from 150 at 10ms.
Jul 2 2002 03:36:00:410PM1020702018Ian HutchinsonFizzle.

D start to 7ms from 10.
OH1 V to 100v from 150 at 7 and 8ms. To 150 from 200V at 5ms.
Jul 2 2002 03:53:34:290PM1020702019Ian HutchinsonFizzle. Nearly 50kA. Still bouncing on outside. Didnt get much effect from my changes.

OH1V to 100V at 3 and 5ms.
Jul 2 2002 04:11:02:330PM1020702020Ian HutchinsonFizzle. Died inside.


Add rcur drawn point at 1ms .68m. Load
Jul 2 2002 04:26:49:110PM1020702021Ian HutchinsonPlasma. Monster bounce. Mostly lucked out. But this shows that the Bz ramp rate it still a lot too small.

rcur drawn to .63 at 10ms.
EF3 voltage to 2500 at 10 and 12 ms.
Jul 2 2002 04:43:55:790PM1020702022Ian HutchinsonFizzle. 40kA.

Br offset to 1.5mT from 2.
Jul 2 2002 05:03:45:897PM1020702023Ian HutchinsonPlasma. Bz fluctuated back up to its proper place.

Repeat
Jul 2 2002 05:03:52:430PM1020702024Ian HutchinsonPlasma.

Engineering Operator Comments
ShotTimeTypeStatusComment
109:19:17:133AMPlasmaOk
209:34:08:557AMPlasmaOk
310:46:33:590AMTestOkOH2U, OH2L & OH1 PS and Feedback Test
411:02:39:867AMPlasmaOk
511:16:35:080AMPlasmaOk
611:31:06:500AMPlasmaOk
711:50:01:463AMPlasmaOk
812:08:19:130PMPlasmaOk
912:28:15:723PMPlasmaOk
1012:47:54:453PMPlasmaOk
1101:08:22:783PMPlasmaOk
1201:28:11:767PMPlasmaOk
1301:47:05:887PMPlasmaOk
1402:04:20:050PMPlasmaOk
1502:21:27:913PMPlasmaOk
1602:42:16:773PMPlasmaOk
1703:00:27:317PMPlasmaOk
1803:18:01:010PMPlasmaOk
1903:33:56:933PMPlasmaOk
2003:51:19:550PMPlasmaOk
2104:08:17:587PMPlasmaOk
2204:25:02:873PMPlasmaOk
2304:41:25:377PMPlasmaOk
2404:59:17:210PMPlasmaOk