Alcator C-Mod Run 1010615 Information

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Miniproposals
Miniproposal:279a
Date Filed:11/17/2000
Title:Neutral point stability research in Alcator C-Mod
First Author:Robert Granetz
Session Leader:Robert Granetz (shots 1-22)

Operators
Session leader(s):Robert Granetz
Physics operator(s):Jim Irby
Engineering operator(s):Gary Dekow,Ed Fitzgerald

Engineering Operator Run Comment
MP279 Neutral Point 11: PO-Irby SL-Granetz EO- fitzgerald,Dekow

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:26:413PM
Author: To Be Determined
Session leader's summary for run 1010615 (Friday):

MP 279a : Neutral point disruption studies

Session leader: R. Granetz
Physics operator: J. Irby
Engineer: E. Fitzgerald

Summary: We actually made it all the way through the planned experiments. We
started off by reconfirming last year's neutral point result that
post-thermal-quench plasmas show enhanced vertical stability when
run about 3 cm above the midplane (shots 8, 9, 11), although we
didn't do quite as well as last year. Then we proceeded to try
out two different PCS programming setups, which we hoped would
promote vertical stability for even longer periods after the
thermal quench. The alternate programming showed some promise
(shots 18, 22), but overall I'd say it didn't do what we had
hoped for. The injector and the silver-doped lithium pellets
worked extremely well. By running at higher density than last year,
we were able to get thermal quenches by firing just one barrel.
The machine ran fairly well, although we had a considerable number
of fizzles today, which I ascribe to the large number of disruptions.

Scorecard: 14 plasmas
6 fizzles
0 duds
0 test
2 aborted and/or screwed up by computer problems
----------
22 total

-------------------------------------------------------------------------------

Run Plan: Extend the encouraging results of last year's neutral point
experiments (MP 264) by programming the hybrid PCS to jump to
specialized feedback programming at the thermal quench, with the
goal of extending the period of post-quench vertical stability.

The specialized programming consists of two possibilities, which
are designed to get around the slow (EF2) response inherent in many
of the usual controllers:

(1) Rapidly move RCUR inward while turning off feedback on CLEARIN
and X-point positions

(2) Install a new controller for CLEARIN which is not forced to be
orthogonal to other estimators. This results in significantly
faster CLEARIN feedback. RCUR and X-point programming is the
same as in option (1).

-------------------------------------------------------------------------------

Shot 01 -- Aborted. ACK failure. No power cycle.

Next shot: Load plasma programming from last year's neutral point
run (1000526022), which is 0.8 MA, 5.3 T, with the plasma about
+3 cm above the midplane. No PCS segment switch on this shot.
Test fire a normal (un-doped) lithium pellet at t=0.800 s to make
sure everything is working.

Shot 02 -- Plasma. Good shot. Got the pellet at about t=0.811 s. Xray
centroid is at z=+3.3 cm.

Next shot: turn on the switch to segment 3 at t=0.815 s. Fire
two silver-doped pellets to disrupt the plasma. I also used the
IDL 'fast_control' menu to set up Mirnov and Xrays to have a fast
window from t=0.8-1.3 s.

Shot 03 -- Plasma. Disrupted at around t=0.815 s. Pellets hit at t=0.812 s.
I don't think the pellets caused a thermal quench though, since
there's no obvious bump on the current.

Next shot: try doubling the density, and only fire one silver-
doped pellet. Move pellet firing time to t=0.795 (5 ms earlier) to
get the 0.810 Thomsom point after the injection. No segment switch
for the next shot.

Note: before shot 5, I got the MFMXD post-disruption analysis MFIL
routines to work again and confirmed that this shot went up.

Shot 04 -- Aborted. Computers hung.

Next shot: try again, but lower ZCUR by 5 mm, since shot 3 went
up (although it didn't disrupt properly).

Shot 05 -- Plasma. Disrupted early, due to excessive density/gas puffing.

Next shot: decrease nl_04 to 1.5e20 m-2, and slow its rampup.

Shot 06 -- Plasma. Nice thermal quench at t=0.810 s. No segment switch on
this shot (on purpose). Plasma moved down at typical speed. We
only needed one doped pellet, thanks to the higher target density
of nl_04=1.6e20 m-2 (Earl's suggestion), so now we'll have enough
pellets to run all day.

Next shot: raise ZCUR by 4 mm; no other changes (no segment switch,
high target density, single silver-doped lithium pellet at
t=0.795 s)

Shot 07 -- Plasma. Disrupted, but I don't think there was a thermal quench.
Moves radially before moving vertically. Confusing. Thomson got
Te=320 eV at t=0.810 s.

Next shot: increase target density a bit, nl_04=1.7e20 m-2. No
other changes.

Shot 08 -- Plasma. Good thermal quench at t=0.808 s. Moved downwards, but
took 2 ms to begin moving. Thomson got a point just after the
thermal quench.

Next shot: move ZCUR up another 4 mm. Still not using/switching
to special programming in segment 3.

Shot 09 -- Plasma. Disrupted just before the pellet though. There was a brief
ohmic H-mode around t=0.5 s. This shot definitely had improved
vertical stability, and eventually went up.

Next shot: turn on segment 3 switch, and reduce ZCUR by 1 mm.

Shot 10 -- Fizzle.

Shot 11 -- Plasma. Disrupted early. Vertically stable, but the current
quench time was very short.

Next shot: drop density a little bit.

Shot 12 -- Fizzle.

Shot 13 -- Plasma. Disrupted just before the pellet fired. Went up at first,
then came back to the midplane.

Next shot: move pellet trigger time to 0.750 s (was 0.795 s). Also
move segment switch time to 0.765 s, and move fast sampling windows
as well. Reduce RCUR by 3 mm to increase outer gap.

Shot 14 -- Fizzle.

Shot 15 -- Fizzle.

Shot 16 -- Fizzle.

Shot 17 -- Plasma. Good thermal quench at t=0.764 s. Alternate programming
switched in at t=0.765 s, consisting of RCUR decrease, and no gain
on CLEARIN or X-point position. This alternate programming did not
enhance vertical stability at all, and may have made it worse.

Next shot: try this alternate PCS segment one more time, with the
gain on RCUR raised to 9.0 (it was 6.15), and if it still doesn't
do anything, switch to the option 2 programming.

Shot 18 -- Plasma. Good thermal quench at t=0.764 s. This shot had improved
vertical stability compared to the previous one. The current
quench was stretched about 3 ms longer. Plasma went up, rather
than down as on the previous shot. Looks encouraging, but we can't
do any better with this PCS setup.

Next shot: try option 2 for the feedback. Everything stays the
same, except that CLEARIN is turned on, with a specially-designed
fast controller.

Shot 19 -- Plasma. Good thermal quench at t=0.764 s. Similar to shot 18...
perhaps a bit worse.

Next shot: Turn off Ip feedback in the post-disruption PCS segment,
and also tweak RCUR and CLEARIN gains up to 9.5.

Shot 20 -- Fizzle.

Shot 21 -- Plasma. Good thermal quench at t=0.765 s. Didn't show any enhanced
vertical stability.

Next shot: program Ip to drop rapidly. Keep all other programming
the unchanged.

Shot 22 -- Plasma. Good thermal quench at t=0.765 s. The current quench
was noticeably stretched out, but I'm not convinced at all the
the special PCS programming was responsible for it.

End of run.

Physics Operator Summaries
Entered: Jul 7 2004 04:37:13:270PM
Author: To Be Determined
ENGINEERING SETUP for Run 1010615: Neutral Point II:

ECDC in D2 overnight

Run begins at 09:00 and ends at 17:00

Power systems as on 1010612011

Gas setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar Hybrid enabled (PG1)
fill B-side upper with 6 psi He Hybrid enabled (PG2)
fill C-side with 30 psi D2 Hybrid enabled (PG3)
fill J-Bottom with 6 psi He Hybrid DISABLED(PG5)

Enable the following gate valves: ECE, DNB, VUV


There will be no need for ICRF during this run.

Results:

The machine ran well after we began ECDC between shots to
cleanup after disruptions. Most of the MP was completed
today. Bob was able to try several different controller
schemes.

********** do not use any shots from today for starting shots
next week since many adjustments have been made to
controllers, Bt, Ip, etc.

Problems:

Had problems with data system slow downs/hangups at beginning
of run. Spanna locked up a couple of times.

Score:

plasmas 14
fizzles 06
computer 02
shot cycles 22

Details:


----------------------------------------------------------------------------
1010615001 irby PHYSICS_OPERATOR Jun 15 2001 9:27:51:540AM
. . . . . . . . . . . . . . . . . . . .
Will try for a Li pellet on the first shot. Switch
to dirty pellets for the next shot.

Standard Data system problem ---- running through as no power shot
----------------------------------------------------------------------------
1010615002 irby PHYSICS_OPERATOR Jun 15 2001 9:29:35:463AM
. . . . . . . . . . . . . . . . . . . .
Plasma --- pellet at 0.8 s


----------------------------------------------------------------------------
1010615003 irby PHYSICS_OPERATOR Jun 15 2001 9:59:46:743AM
. . . . . . . . . . . . . . . . . . . .
Double dopy pellet --- killed plasma


**************** no shot 4 ***********************

----------------------------------------------------------------------------
1010615005 irby PHYSICS_OPERATOR Jun 15 2001 10:48:48:553AM
. . . . . . . . . . . . . . . . . . . .
NL_04 request doubled from 1.e20 to 2e20 m-2

Pellets start moved to 0.795 s from 0.800 s

Ramping down TF starting 1 s

Ramping current down starting at 1 s

Segment #3 if off

Decreased ZCUR in seg 2 by .005 m from .0210 to .0160 m


Density request too much and too soon --- lost plasma at .53 s


----------------------------------------------------------------------------
1010615006 irby PHYSICS_OPERATOR Jun 15 2001 11:04:31:733AM
. . . . . . . . . . . . . . . . . . . .
Dropped density request to 1.5e20 m-2
Also delayed density rise

Nice plasma --- downward going disrupt
----------------------------------------------------------------------------
1010615007 irby PHYSICS_OPERATOR Jun 15 2001 11:20:33:680AM
. . . . . . . . . . . . . . . . . . . .
Moved ZCUR back up 4 mm to .02 m

Good shot


----------------------------------------------------------------------------
1010615008 irby PHYSICS_OPERATOR Jun 15 2001 11:38:35:850AM
. . . . . . . . . . . . . . . . . . . .
Density request to 1.7e20 m-2

Got more density --- Bob claims thermal quench

----------------------------------------------------------------------------
1010615009 irby PHYSICS_OPERATOR Jun 15 2001 11:59:31:833AM
. . . . . . . . . . . . . . . . . . . .
ZCUR to 0.024 m from .020 m --- Bob searching for neutral point

Plasma

Looks like we got and ohmic H-mode at .5 s



----------------------------------------------------------------------------
1010615010 irby PHYSICS_OPERATOR Jun 15 2001 12:13:13:620PM
. . . . . . . . . . . . . . . . . . . .
ZCUR down 1 mm to .023 m

Fizzle??


----------------------------------------------------------------------------
1010615011 irby PHYSICS_OPERATOR Jun 15 2001 12:39:47:146PM
. . . . . . . . . . . . . . . . . . . .
Turned on seg 3

Lost plasma early --- density still too high early on


----------------------------------------------------------------------------
1010615012 irby PHYSICS_OPERATOR Jun 15 2001 1:02:52:276PM
. . . . . . . . . . . . . . . . . . . .
Dropped density below 1e20 before 0.5 s, dropped to 1.5e20 late
in shot

B-side-upper disabled --- we were puffing helium at 6 psi.

Fizzle again ---- note Br0 is somewhat too positive


Time (ms): 0 5 10 25
----------------------------------------
Ip (kA): 2.0337 -13.5540 -29.1190 -23.9534
dIp/dt (kA/ms): -1.5282 -3.0542 -1.6520 0.0000
pressure (mTorr): 0.0809 0.0782 0.0800 0.0782
Bz0 (mT): -3.1570 -0.3200 1.4398 16.8505
Br0 (mT): 0.4596 0.0199 -0.1480 -0.5050
----------------------------------------------------------------------------
1010615013 irby PHYSICS_OPERATOR Jun 15 2001 1:25:31:530PM
. . . . . . . . . . . . . . . . . . . .
Dropped Br0 offset from .002 to .001 T

Reduced prefil by 2 ms.

Plasma --- lost it before pellet injection time, but pellet fired

Got lower fill and more negative Br0 as asked for
----------------------------------------------------------------------------
1010615014 irby PHYSICS_OPERATOR Jun 15 2001 1:44:22:416PM
. . . . . . . . . . . . . . . . . . . .
Seg 3 start moved to 0.7650 from 0.815 s
Launching pellet at 0.75 s

Reduced RCUR from 0.6645 to 0.6615 m

Fizzle
----------------------------------------------------------------------------
1010615015 irby PHYSICS_OPERATOR Jun 15 2001 2:11:00:426PM
. . . . . . . . . . . . . . . . . . . .
Fizzle --- two in a row!


----------------------------------------------------------------------------
1010615016 irby PHYSICS_OPERATOR Jun 15 2001 2:25:13:543PM
. . . . . . . . . . . . . . . . . . . .
Raised Br0 by .0005 T: offset .0015

Fizzle! Start between shot ecdc
----------------------------------------------------------------------------
1010615017 irby PHYSICS_OPERATOR Jun 15 2001 2:55:02:793PM
. . . . . . . . . . . . . . . . . . . .
Ran 10 minutes ECDC before this shot

Plasma again --- and we made it past pellet time

No sign of seg 3 improvement

----------------------------------------------------------------------------
1010615018 irby PHYSICS_OPERATOR Jun 15 2001 3:27:50:046PM
. . . . . . . . . . . . . . . . . . . .
Continued ECDC between shots

Increased gain on RCUR to 9 from 6.15

Good shot ---



----------------------------------------------------------------------------
1010615019 irby PHYSICS_OPERATOR Jun 15 2001 3:54:50:806PM
. . . . . . . . . . . . . . . . . . . .
Loaded seg 4 CLEARIN into seg 3 ---- try another controller without
much ef2 component

Plasma --- no real improvement
----------------------------------------------------------------------------
1010615020 irby PHYSICS_OPERATOR Jun 15 2001 4:12:06:420PM
. . . . . . . . . . . . . . . . . . . .
CLEARIN and RCUR gains to 9.5 from 9.0

Ip gain in seg 3 reduced to 0

Fizzle!

I may have let the fill drift too high

Time (ms): 0 5 10 25
----------------------------------------
Ip (kA): 2.0337 -13.5540 -26.5021 -23.9534
dIp/dt (kA/ms): -1.5282 -2.5444 -1.5249 -0.0011
pressure (mTorr): 0.0958 0.0936 0.0947 0.1002
Bz0 (mT): -3.9291 -0.2549 1.7084 16.2146
Br0 (mT): -0.2757 -1.1286 -0.6903 -1.0262
----------------------------------------------------------------------------
1010615021 irby PHYSICS_OPERATOR Jun 15 2001 4:49:42:806PM
. . . . . . . . . . . . . . . . . . . .
Good shot


----------------------------------------------------------------------------
1010615022 irby PHYSICS_OPERATOR Jun 15 2001 4:59:22:400PM
. . . . . . . . . . . . . . . . . . . .
Put gain back on Ip, but dropped it to 100kA in seg 3.

Plasma --- end of run

Session Leader Comments
Jun 15 2001 09:11:50:937AMRobert GranetzRun Plan: Extend the encouraging results of last year's neutral point
experiments (MP 264) by programming the hybrid PCS to jump to
specialized feedback programming at the thermal quench, with the
goal of extending the period of post-quench vertical stability.

The specialized programming consists of two possibilities, which
are designed to get around the slow (EF2) response inherent in many
of the usual controllers:

(1) Rapidly move RCUR inward while turning off feedback on CLEARIN
and X-point positions

(2) Install a new controller for CLEARIN which is not forced to be
orthogonal to other estimators. This results in significantly
faster CLEARIN feedback. RCUR and X-point programming is the
same as in option (1).
Jun 15 2001 09:12:11:017AM1010615001Robert GranetzShot 01 -- Test. No power cycle.

Next shot: Load plasma programming from last year's neutral point
run (1000526022), which is 0.8 MA, 5.3 T, with the plasma about
+3 cm above the midplane. No PCS segment switch on this shot.
Test fire a normal (un-doped) lithium pellet at t=0.800 s to make
sure everything is working.
Jun 15 2001 09:41:42:060AM1010615002Robert GranetzShot 02 -- Plasma. Good shot. Got the pellet at about t=0.811 s. Xray
centroid is at z=+3.3 cm.

Next shot: turn on the switch to segment 3 at t=0.815 s. Fire
two silver-doped pellets to disrupt the plasma. I also used the
IDL 'fast_control' menu to set up Mirnov and Xrays to have a fast
window from t=0.8-1.3 s.
Jun 15 2001 10:01:52:480AM1010615003Robert GranetzShot 03 -- Plasma. Disrupted at around t=0.815 s. Pellets hit at t=0.812 s.
I don't think the pellets caused a thermal quench though, since
there's no obvious bump on the current.

Next shot: try doubling the density, and only fire one silver-
doped pellet. Move pellet firing time to t=0.795 (5 ms earlier) to
get the 0.810 Thomsom point after the injection. No segment switch
for the next shot.
Jun 15 2001 10:31:09:027AM1010615003Robert Granetz Note: before shot 5, I got the MFMXD post-disruption analysis MFIL
routines to work again and confirmed that this shot went up.
Jun 15 2001 10:31:25:950AM1010615004Robert GranetzShot 04 -- Aborted.

Next shot: try again, but lower ZCUR by 5 mm, since shot 3 went
up (although it didn't disrupt properly).
Jun 15 2001 10:43:43:390AM1010615005Robert GranetzShot 05 -- Plasma. Disrupted early, due to excessive density/gas puffing.

Next shot: decrease nl_04 to 1.5e20 m-2, and slow its rampup.
Jun 15 2001 11:08:54:197AM1010615006Robert GranetzShot 06 -- Plasma. Nice thermal quench at t=0.810 s. No segment switch on
this shot (on purpose). Plasma moved down at typical speed. We
only needed one doped pellet, thanks to the higher target density
of nl_04=1.6e20 m-2 (Earl's suggestion), so now we'll have enough
pellets to run all day.

Next shot: raise ZCUR by 4 mm; no other changes (no segment switch,
high target density, single silver-doped lithium pellet at
t=0.795 s)
Jun 15 2001 11:22:51:747AM1010615007Robert GranetzShot 07 -- Plasma. Disrupted, but I don't think there was a thermal quench.
Moves radially before moving vertically. Confusing.

Next shot: increase target density a bit, nl_04=1.7e20 m-2. No
other changes.
Jun 15 2001 11:44:18:060AM1010615008Robert GranetzShot 08 -- Plasma. Good thermal quench at t=0.808 s. Moved downwards, but
took 2 ms to begin moving. Thomson got a point just after the
thermal quench.

Next shot: move ZCUR up another 4 mm. Still not using/switching
to special programming in segment 3.
Jun 15 2001 12:07:26:050PM1010615009Robert GranetzShot 09 -- Plasma. Disrupted just before the pellet though. There was a brief
ohmic H-mode around t=0.5 s. This shot definitely had improved
vertical stability, and eventually went up.

Next shot: turn on segment 3 switch, and reduce ZCUR by 1 mm.
Jun 15 2001 12:11:31:243PM1010615010Robert GranetzShot 10 -- Fizzle.
Jun 15 2001 12:53:54:420PM1010615011Robert GranetzShot 11 -- Plasma. Disrupted early. Vertically stable, but the current
quench time was very short.

Next shot: drop density a little bit.
Jun 15 2001 12:56:15:797PM1010615012Robert GranetzShot 12 -- Fizzle.
Jun 15 2001 01:36:11:577PM1010615013Robert GranetzShot 13 -- Plasma. Disrupted just before the pellet fired. Went up at first,
then came back to the midplane.

Next shot: move pellet trigger time to 0.750 s (was 0.795 s). Also
move segment switch time to 0.765 s, and move fast sampling windows
as well. Reduce RCUR by 3 mm to increase outer gap.
Jun 15 2001 02:01:35:367PM1010615014Robert GranetzShot 14 -- Fizzle.
Jun 15 2001 02:00:57:770PM1010615015Robert GranetzShot 15 -- Fizzle.
Jun 15 2001 02:25:26:137PM1010615016Robert GranetzShot 16 -- Fizzle.
Jun 15 2001 03:12:11:427PM1010615017Robert GranetzShot 17 -- Plasma. Good thermal quench at t=0.764 s. Alternate programming
switched in at t=0.765 s, consisting of RCUR decrease, and no gain
on CLEARIN or X-point position. This alternate programming did not
enhance vertical stability at all, and may have made it worse.

Next shot: try this alternate PCS segment one more time, with the
gain on RCUR raised to 9.0 (it was 6.15), and if it still doesn't
do anything, switch to the option 2 programming.
Jun 15 2001 03:36:19:370PM1010615018Robert GranetzShot 18 -- Plasma. Good thermal quench at t=0.764 s. This shot had improved
vertical stability compared to the previous one. The current
quench was stretched about 3 ms longer. Plasma went up, rather
than down as on the previous shot. Looks encouraging, but we can't
do any better with this PCS setup.

Next shot: try option 2 for the feedback. Everything stays the
same, except that CLEARIN is turned on, with a specially-designed
fast controller.
Jun 15 2001 03:53:45:977PM1010615019Robert GranetzShot 19 -- Plasma. Good thermal quench at t=0.764 s. Similar to shot 18...
perhaps a bit worse.

Next shot: Turn off Ip feedback in the post-disruption PCS segment,
and also tweak RCUR and CLEARIN gains up to 9.5.
Jun 15 2001 04:09:10:280PM1010615020Robert GranetzShot 20 -- Fizzle.
Jun 15 2001 05:10:49:603PM1010615021Robert GranetzShot 21 -- Plasma. Good thermal quench at t=0.765 s. Didn't show any enhanced
vertical stability.

Next shot: program Ip to drop rapidly. Keep all other programming
the unchanged.
Jun 15 2001 05:08:28:553PM1010615022Robert GranetzShot 22 -- Plasma. Good thermal quench at t=0.765 s. The current quench
was noticeably stretched out, but I'm not convinced at all the
the special PCS programming was responsible for it.

End of run.

Physics Operator Comments
Jun 15 2001 09:27:51:540AM1010615001Jim IrbyWill try for a Li pellet on the first shot. Switch
to dirty pellets for the next shot.

Standard Data system problem ---- running through as no power shot
Jun 15 2001 09:29:35:463AM1010615002Jim IrbyPlasma --- pellet at 0.8 s


Jun 15 2001 09:59:46:743AM1010615003Jim IrbyDouble dopy pellet --- killed plasma


Jun 15 2001 10:48:48:553AM1010615005Jim IrbyNL_04 request doubled from 1.e20 to 2e20 m-2

Pellets start moved to 0.795 s from 0.800 s

Ramping down TF starting 1 s

Ramping current down starting at 1 s

Segment #3 if off

Decreased ZCUR in seg 2 by .005 m from .0210 to .0160 m


Density request to much and too soon --- lost plasma at .53 s


Jun 15 2001 11:04:31:733AM1010615006Jim IrbyDropped density request to 1.5e20 m-2
Also delayed density rise

Nice plasma --- downward going disrupt
Jun 15 2001 11:20:33:680AM1010615007Jim IrbyMoved ZCUR back up 4 mm to .02 m

Good shot


Jun 15 2001 11:38:35:850AM1010615008Jim IrbyDensity request to 1.7e20 m-2

Got more density --- Bob claims thermal quinch

Jun 15 2001 11:59:31:833AM1010615009Jim IrbyZCUR to 0.024 m from .020 m --- Bob searching for neutral point

Plasma

Looks like we got and ohmic H-mode at .5 s



Jun 15 2001 12:13:13:620PM1010615010Jim IrbyZCUR down 1 mm to .023 m

Fizzle??


Jun 15 2001 12:39:47:147PM1010615011Jim IrbyTurned on seg 3

Lost plasma early --- density still too high early on


Jun 15 2001 01:02:52:277PM1010615012Jim IrbyDropped density below 1e20 before 0.5 s, dropped to 1.5e20 late
in shot

B-side-upper disabled --- we were puffing helium at 6 psi.

Fizzle again ---- note Br0 is somewhat too positive


Time (ms): 0 5 10 25
----------------------------------------
Ip (kA): 2.0337 -13.5540 -29.1190 -23.9534
dIp/dt (kA/ms): -1.5282 -3.0542 -1.6520 0.0000
pressure (mTorr): 0.0809 0.0782 0.0800 0.0782
Bz0 (mT): -3.1570 -0.3200 1.4398 16.8505
Br0 (mT): 0.4596 0.0199 -0.1480 -0.5050
Jun 15 2001 01:25:31:530PM1010615013Jim IrbyDropped Br0 offset from .002 to .001 T

Reduced prefil by 2 ms.

Plasma --- lost it before pellet injection time, but pellet fired

Got lower fill and more negative Br0 as asked for
Jun 15 2001 01:44:22:417PM1010615014Jim IrbySeg 3 start moved to 0.7650 from 0.815 s
Launching pellet at 0.75 s

Reduced RCUR from 0.6645 to 0.6615 m

Fizzle
Jun 15 2001 02:11:00:427PM1010615015Jim IrbyFizzle --- two in a row!


Jun 15 2001 02:25:13:543PM1010615016Jim IrbyRaised Br0 by .0005 T: offset .0015

Fizzle! Start between shot ecdc
Jun 15 2001 02:55:02:793PM1010615017Jim IrbyRan 10 minutes ECDC before this shot

Plasma again --- and we made it past pellet time

No sign of seg 3 improvement

Jun 15 2001 03:27:50:047PM1010615018Jim IrbyContinued ECDC between shots

Increased gain on RCUR to 9 from 6.15

Good shot ---



Jun 15 2001 03:54:50:807PM1010615019Jim IrbyLoaded seg 4 CLEARIN into seg 3 ---- try another controller without
much ef2 component

Plasma --- no real improvement
Jun 15 2001 04:12:06:420PM1010615020Jim IrbyCLEARIN and RCUR gains to 9.5 from 9.0

Ip gain in seg 3 reduced to 0

Fizzle!

I may have let the fill drift too high

Time (ms): 0 5 10 25
----------------------------------------
Ip (kA): 2.0337 -13.5540 -26.5021 -23.9534
dIp/dt (kA/ms): -1.5282 -2.5444 -1.5249 -0.0011
pressure (mTorr): 0.0958 0.0936 0.0947 0.1002
Bz0 (mT): -3.9291 -0.2549 1.7084 16.2146
Br0 (mT): -0.2757 -1.1286 -0.6903 -1.0262
Jun 15 2001 04:49:42:807PM1010615021Jim IrbyGood shot


Jun 15 2001 04:59:22:400PM1010615022Jim IrbyPut gain back on Ip, but dropped it to 100kA in seg 3.

Plasma --- end of run

Engineering Operator Comments
ShotTimeTypeStatusComment
109:05:51:160AMPlasmaBadIgor failure no power shot
209:23:03:360AMPlasmaOk
309:45:02:380AMPlasmaOk
410:26:23:050AMTestBad
510:36:02:940AMPlasmaOk
610:53:02:310AMPlasmaOk
711:11:51:213AMPlasmaOk
811:31:01:933AMPlasmaOk
911:51:27:433AMPlasmaOk
1012:08:23:223PMPlasmaOk
1112:33:40:840PMPlasmaOk
1212:54:35:497PMPlasmaOk
1301:13:23:887PMPlasmaOk
1401:37:39:220PMPlasmaOk
1501:59:20:753PMPlasmaOk
1602:21:07:350PMPlasmaOk
1702:49:40:863PMPlasmaOk
1803:16:10:683PMPlasmaOk
1903:41:44:787PMPlasmaOk
2004:07:28:730PMPlasmaOk
2104:31:51:560PMPlasmaOk
2204:57:01:537PMPlasmaOk