Alcator C-Mod Run 1000517 Information

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Miniproposals
Miniproposal:267
Date Filed: 4/4/2000
Title:Dependence of SOL Fluctuations and Particle Transport on Collisionality
First Author:Brian Labombard
Session Leader:Brian Labombard (shots 1-26)

Operators
Session leader(s):Brian Labombard
Physics operator(s):Ian Hutchinson
Engineering operator(s):Bill Cochran

Engineering Operator Run Comment
Run Plan for first day of MP#267. Hutchinson/Labombard/Cochran.

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:23:337PM
Author: To Be Determined
MP#267
"Dependence of SOL Fluctuations and Particle Transport on Collisionality"

Session Leader - B. LaBombard
Phys Op - I. Hutchinson

==============================================================================
Run Plan for first day of MP#267

The purpose of these experiments is to explore the dependence of
SOL fluctuation characteristics and attendant cross-field particle
transport on the collisionality of the SOL.

The key diagnostics which must be operational for this study are:
(a) A-port and F-port scanning probes operated
in a fluctuation mode (The A-port probe will be used in both a
spatially scanning and a fixed position mode.), (b) divertor probes
operated in a fluctuation mode, (c) fast visible diodes viewing helium
puffed from the A/B limiter capillary, (d) tangential Ly-alpha diode array,
(e) limiter particle flux probes, and (f) edge thomson scattering.

Day 1: Fine density scan at fixed plasma current (0.8 MA) and
toroidal field (5.3 tesla).

Start with reload of shot#1000516010 which was a 1.0 MA
shot. Then go to 0.8 MA.

Shot#1-3
NL01 = 1.0x10^20 m^-2
Setup equilibrium and FSP/ASP target

Begin density scan with two shots at each density.
Alternate between A-port probe in scanning- and fixed-location modes

Shot#4,5 - NL01 = 1.0
6,7 - NL01 = 1.0, flapper open
8,9 - NL01 = 0.9
10,11 - NL01 = 0.8
12,13 - NL01 = 0.8, flapper open
14,15 - NL01 = 0.7
16,17 - NL01 = 0.6
18,19,20 - NL01 = 1.1
21,22 - NL01 = 1.2
23,24 - NL01 = 1.3
25,26 - NL01 = 1.4

==============================================================================
Results:

We wanted a 'fine' density scan, we got a 'coarse' one.
Between probe targeting, probe timing errors (from a run-away
batch job), fizzles and a disruption, it took 9 shots to get started
on the data path. Fizzles were persistent and in the end the a total of 11
good-data shots were gathered. Flapper-open shots were jettisoned
from the plan early. Only one flapper-one shot was recorded but unfortunately
the A-port probe was not at a fixed location (as Ben would have liked).

We did get some scanning probe profile data and fluctuation data from the
scanning probes and divertor probes over the full density range, however. This
should be adequate to study changes in the turbulence/transport behavior.

The A-port probe appeared to operate reasonably well in a fixed-location
mode. However, concern that the probe would get 'toasted' kept us from
exploring how deep we could insert it. Partly as a consequence, the 'fixed location'
of the A-port probe varied quite a bit from shot-to-shot. Hopefully, the dependence
of fluctuation characteristics on plasma density and probe position in the
SOL can be sorted out.

The fluctuations recorded by the scanning probes clearly showed
differences as the density was lowered. At low density, the fluctuation level
at the separatrix (delta I/I) appeared to be much lower, increasing with
distance from the separatrix.

As has been see previously at low density, both mach probes record a strong
'reverse' flow, favoring higher Isat on the West probe relative to the East probe.
It was noted that when this strong flow occurs, the down-stream probes of
the Mach probes (East) see much more Isat fluctuation than the upstream probes
(West). This is perhaps evidence that the 'wake' of the probe has a higher
turbulence level as plasma attempts to 'fill it in'.

Detailed Shot log:

01 - F
02 - NL04=1.0
ASP and FSP probes scanning far SOL,
mode B - ASP in fixed mode
He puffed from NINJA from this shot on
03 - NL04=1.0
ASP and FSP probes scanning far SOL,
mode A - ASP in scanning mode - timing is wrong!
04 - NL04=1.0
ASP and FSP probes scanning far SOL,
mode A - ASP in scanning mode with correct timing
05 - NL04=1.0
ASP and FSP probes scanning,
mode B - ASP in fixed position mode
Scan timing was off.
06 - F
07 - disrupted at 0.5 sec
08 - F
09 - NL04=1.0
ASP and FSP probes scanning,
mode A - ASP in multi-scan mode
Got .9 and 1.2 scans.
Flapper open.
10 - F
11 - NL04=0.8
ASP and FSP probes scanning,
mode A - ASP in scanning mode
Flapper closed from this shot on
12 - NL04=0.8
ASP and FSP probes scanning,
mode B - ASP in fixed mode - very nice data!
13 - NL04=0.7
FSP scanning
mode B - ASP in fixed mode
14 - F
15 - NL04=0.7
FSP scanning
mode A - ASP in scanning mode
ASP a little over-inserted on .9 sec scan.
16 - F
17 - NL04=0.5
FSP scanning
mode A - ASP in scanning mode
Good data.
18 - NL04=0.5
FSP scanning
mode B - ASP in fixed mode
Very nice data.
19 - NL04=1.0
FSP scanning
mode B - ASP in fixed mode
Good data
20 - F
21 - F
22 - NL04=1.1
FSP scanning
mode A - ASP in scanning mode
West power supply is off! East data looks good.
23 - NL04=1.4
FSP scanning
mode A - ASP in scanning mode
data look good
24 - F
25 - disrupts early
26 - NL04=0.9
FSP scanning
mode B - ASP in fixed mode

Physics Operator Summaries
Entered: Jul 7 2004 04:37:10:770PM
Author: To Be Determined
Physop 1000517 MP267 Probe Density Scan.

SL LaBombard
PO Hutch

Summary
_______

A good fraction of the planned density scan was obtained. It would all have
been obtained if not for the significant number of fizzles, lowering the
total plasma count.


Physop Insider Chat
___________________

I tweaked the null to decrease the field gradient. This is helpful for
preventing vertical position problems in the first 30ms. However,
there still seems to be a problem with late breakdowns. It was not
obvious how to fix those, although lowering the fill pressure (below
.065mT including the DNB contribution) seems to help and I did not use
the lower pressure consistently, though maybe I should have done.
Perhaps the extra freedom allowed by the index improvement will give
us a robust scenario. Anyway, currently we don't really seem to have
one. Judging by the Bz traces, my tweaks on EF3V early seem not to
have done anything. This is surprising on the basis of previous
experience.

I showed that the end of the shot radial position problems can be largely
attributed to the rcur control of EF3. EF3 needs a big negative voltage,
about -300V to ramp it down at the rate needed to match the current ramp-
down. If that voltage is applied using the V-signal, then the tendency of
the plasma to move inwards is significantly decreased, and position is
reasonably well controlled down to <200kA.

Scorecard
_________

Shot,Duration(s),Ipmax(MA) Shot,Duration(s),Ipmax
1 0.000 0.032 2 1.925 0.805
3 1.898 0.802 4 1.914 0.802
5 1.915 0.805 6 0.000 0.029
7 0.501 0.794 8 0.000 0.034
9 1.609 0.802 10 0.000 0.034
11 1.924 0.805 12 1.932 0.805
13 1.941 0.807 14 0.000 0.037
15 1.939 0.807 16 0.000 0.039
17 1.936 0.815 18 1.938 0.818
19 1.848 0.805 20 0.000 0.029
21 0.000 0.034 22 1.860 0.802
23 1.634 0.797 24 0.000 0.026
25 0.295 0.810 26 1.946 0.805

Finished summary for 1000517 Total of 26 shots.
26 shots. 17 plasmas. 9 fizzles. 0 duds.


Details
_______


----------------------------------------------------------------------------
1000517xxx hutch PHYSICS_OPERATOR May 17 2000 8:52:38:543AM
. . . . . . . . . . . . . . . . . . . .
MP 267 Dependence of SOL Fluctuations and
Cold Start
Start PCS
Load from 1000516010
C-side PG3 30psi D2; B-top PG4 6psi D2; B-sideLOWER 1psi Ar.

Set Ip to .8MA. TF current to 148kA. In segment 2.
----------------------------------------------------------------------------
1000517xxx hutch PHYSICS_OPERATOR May 17 2000 1:49:50:530PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

(Accidentally somehow got logged out. Back now)
nl04 to .5e20
----------------------------------------------------------------------------
1000517001 hutch PHYSICS_OPERATOR May 17 2000 9:13:38:513AM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Ip/Bz is way too high. Nice early breakdown. DNB did not open
so the fill is rather low. Bz is too low.

ICEF4 to -1275A from -1290
----------------------------------------------------------------------------
1000517002 hutch PHYSICS_OPERATOR May 17 2000 9:37:02:856AM
. . . . . . . . . . . . . . . . . . . .
Plasma. Slightly later breakdown, but a good Ip pickup.
nl04=1.e20. Ip 790kA. Gaps fine.

Brian is worried about the separatrix moving away from probe at 1.2s.
Make rcur move out at 1.25s to .665 from .663.
----------------------------------------------------------------------------
1000517003 hutch PHYSICS_OPERATOR May 17 2000 9:54:03:496AM
. . . . . . . . . . . . . . . . . . . .
Plasma. Unpleasant injection at .88s. Current rise reasonable.

No changes
----------------------------------------------------------------------------
1000517004 hutch PHYSICS_OPERATOR May 17 2000 10:17:51:170AM
. . . . . . . . . . . . . . . . . . . .
Plasma.

Add Krypton puff on BsideUpper, PG2 2psi 50ms at 1.3-1.35s
----------------------------------------------------------------------------
1000517005 hutch PHYSICS_OPERATOR May 17 2000 10:35:20:450AM
. . . . . . . . . . . . . . . . . . . .
Plasma. Forgot to enable the Krypton. Do so next shot.
----------------------------------------------------------------------------
1000517006 hutch PHYSICS_OPERATOR May 17 2000 10:58:20:560AM
. . . . . . . . . . . . . . . . . . . .
Fizzle. No obvious magnetics reason. Breakdown slightly late/ragged.

Install EF3 voltage at 300V at 1.4s to see effect of offset.
ICEF4 to -1270
----------------------------------------------------------------------------
1000517007 hutch PHYSICS_OPERATOR May 17 2000 11:13:51:826AM
. . . . . . . . . . . . . . . . . . . .
Plasma Disrupts at 0.5s. Caused by a monstrous injection.

Return ICEF4 to -1275. Br offset to -.0002
----------------------------------------------------------------------------
1000517008 hutch PHYSICS_OPERATOR May 17 2000 11:31:36:326AM
. . . . . . . . . . . . . . . . . . . .
Fizzle.


Br offset to +.0002. Looks as if it dislikes the negative.
----------------------------------------------------------------------------
1000517009 hutch PHYSICS_OPERATOR May 17 2000 11:54:40:293AM
. . . . . . . . . . . . . . . . . . . .
Plasma. Disrupts at 1.6s because the Krypton is way too much.

Reduce the krypton puff to 20ms.
Add 2mm to rcur to reduce outer gap by 4mm.
----------------------------------------------------------------------------
1000517010 hutch PHYSICS_OPERATOR May 17 2000 12:13:08:483PM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Looks like a vertical problem at 15ms. Probably we've got too much
field gradient.

OH2V to 25V at .01s (was 16V)
nl04 to .8e20
----------------------------------------------------------------------------
1000517011 hutch PHYSICS_OPERATOR May 17 2000 12:33:21:340PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

Move the slow zcur gain turn on to 20ms in segment 1.
OH2 to +30V at 7ms.
Kr pulse to 30ms.
Rcur to .669 at 2s
EF3V to +30 at 1.1s and negative in ramp-down.
Rcur to .6665 at .9s
----------------------------------------------------------------------------
1000517012 hutch PHYSICS_OPERATOR May 17 2000 12:52:36:013PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Saw some reasonable responses to the tweaks.
Krypton is visible; about .1MW on 2pix2.2.


nl04 to .7e20
OH2V to 35V
EF3V to 2480 from 2414 at .01s.
----------------------------------------------------------------------------
1000517013 hutch PHYSICS_OPERATOR May 17 2000 1:13:01:996PM
. . . . . . . . . . . . . . . . . . . .
Plasma. We've definitely lowered the initial field gradient. zcur looks better.


EF3 more negative (-300V) at 2s.
----------------------------------------------------------------------------
1000517014 hutch PHYSICS_OPERATOR May 17 2000 1:29:26:810PM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Still appears to be a vertical problem at 15ms. Breakdown a little
late but got to 20kA gas current.

OH2s to 45V at 7-10ms.
----------------------------------------------------------------------------
1000517015 hutch PHYSICS_OPERATOR May 17 2000 2:06:33:153PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

nl04 to .5e20
----------------------------------------------------------------------------
1000517016 hutch PHYSICS_OPERATOR May 17 2000 2:06:19:996PM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Br was very different that shot. And again we seem to have a vertical
problem. Although Ip/Bz hardly reaches 2. Breakdown is late. 6.6ms.

EF3V to 2400V at 10ms.
nl04 .5e20
----------------------------------------------------------------------------
1000517017 hutch PHYSICS_OPERATOR May 17 2000 2:28:44:780PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Got about 6.e19.

Lower the pg3 V at 200ms to stop overshoot of density.
ICef4 to -1280 from -1275
----------------------------------------------------------------------------
1000517018 hutch PHYSICS_OPERATOR May 17 2000 2:54:39:436PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Breakdown slightly earlier 5.8ms. That seems to help the current rise.

nl04 to 1.1e20
Drop clearin at about 1.8s because we are going vertically unstable at the
end apparently.
----------------------------------------------------------------------------
1000517019 hutch PHYSICS_OPERATOR May 17 2000 3:14:51:640PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

Add TF back porch. Raise PG3 V fueling level.
Krypton to 25ms.
Raise nl04 at .3s.
----------------------------------------------------------------------------
1000517020 hutch PHYSICS_OPERATOR May 17 2000 3:30:20:450PM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Gas current does not exceed 10kA. Breakdown is late 6.4ms. Br rather
negative.

Br offset to +.0005
----------------------------------------------------------------------------
1000517021 hutch PHYSICS_OPERATOR May 17 2000 3:46:32:686PM
. . . . . . . . . . . . . . . . . . . .
Fizzle.

V-EF3 to 2300 at 10ms.
Br offset to .0003.
----------------------------------------------------------------------------
1000517022 hutch PHYSICS_OPERATOR May 17 2000 4:09:33:436PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

EF3 to 2200V at 10ms.
nl04 to 1.4e20
----------------------------------------------------------------------------
1000517023 hutch PHYSICS_OPERATOR May 17 2000 4:29:22:013PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Disrupts at 1.6s. Extremely slow current initial current rise.
EF1U rails at 1.33s.

Krypton to 5ms.
Ef3V to 2100 at 10ms. Lower Density slightly.
----------------------------------------------------------------------------
1000517024 hutch PHYSICS_OPERATOR May 17 2000 4:44:59:030PM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Ghastly slow current rise.

Lower fill puff to 17ms from 20ms.
----------------------------------------------------------------------------
1000517025 hutch PHYSICS_OPERATOR May 17 2000 4:53:03:560PM
. . . . . . . . . . . . . . . . . . . .
Plasma disrupts at .27. Too much gas too early.

Try for nl04=.9e20
----------------------------------------------------------------------------
1000517026 hutch PHYSICS_OPERATOR May 17 2000 5:04:02:763PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

Session Leader Comments
May 17 2000 10:38:16:060AMBrian LabombardRun Plan for first day of MP#267

"Dependence of SOL Fluctuations and Particle Transport on Collisionality"

The purpose of these experiments is to explore the dependence of
SOL fluctuation characteristics and attendant cross-field particle
transport on the collisionality of the SOL.

The key diagnostics which must be operational for this study are:
(a) A-port and F-port scanning probes operated
in a fluctuation mode (The A-port probe will be used in both a
spatially scanning and a fixed position mode.), (b) divertor probes
operated in a fluctuation mode, (c) fast visible diodes viewing helium
puffed from the A/B limiter capillary, (d) tangential Ly-alpha diode array,
(e) limiter particle flux probes, and (f) edge thomson scattering.

Day 1: Fine density scan at fixed plasma current (0.8 MA) and
toroidal field (5.3 tesla).

Start with reload of shot#1000516010 which was a 1.0 MA
shot. Then go to 0.8 MA.

Shot#1-3
NL04 = 1.0x10^20 m^-2
Setup equilibrium and FSP/ASP target

Begin density scan with two shots at each density.
Alternate between A-port probe in scanning- and fixed-location modes

Shot#4,5 - NL04 = 1.0
6,7 - NL04 = 1.0, flapper open
8,9 - NL04 = 0.9
10,11 - NL04 = 0.8
12,13 - NL04 = 0.8, flapper open
14,15 - NL04 = 0.7
16,17 - NL04 = 0.6
18,19,20 - NL04 = 1.1
21,22 - NL04 = 1.2
23,24 - NL04 = 1.3
25,26 - NL04 = 1.4
May 17 2000 10:01:57:030AM1000517004Brian Labombardshot 4 - ASP and FSP probes scanning far SOL,
mode A - ASP in scanning mode with correct timing

NL04 - 1.0
May 17 2000 10:25:53:793AM1000517005Brian Labombardshot 5 - ASP and FSP probes scanning,
mode B - ASP in single scan mode
Scan timing was off. Need to repeat shot.

NL04 - 1.0
May 17 2000 10:47:27:403AM1000517006Brian Labombardshot 6 - ASP and FSP probes scanning,
mode B - ASP in single scan mode - scan timing is now correct.
No plasma - repeat setup on next shot.

May 17 2000 11:08:24:297AM1000517007Brian Labombardshot 7 - ASP and FSP probes scanning,
mode B - ASP in single scan mode - scan timing is now correct.
Disrupted around .5 - could be caused by ASP overheating
in its fixed-location mode.

Next shot: go back to scanning ASP with flapper on.

May 17 2000 11:39:22:920AM1000517009Brian Labombardshot 9 - ASP and FSP probes scanning,
mode A - ASP in multi-scan mode
Got .9 and 1.2 scans.

Flapper open.

Next shot, fixed position mode. with flapper open

May 17 2000 12:47:19:513PM1000517010Brian Labombardshot 10 - ASP and FSP probes scanning,
mode B - ASP in fixed mode.

Flapper open.

No plasma. Next shot, flapper closed, go to NL04 = 0.8

May 17 2000 12:26:11:390PM1000517011Brian Labombardshot 11 - ASP and FSP probes scanning,
mode A - ASP in scanning mode
NL04 = 0.8

Next shot, repeat with fixed ASP position

May 17 2000 12:47:00:187PM1000517012Brian Labombardshot 12 - ASP and FSP probes scanning,
mode B - ASP in fixed mode - very nice data!
NL04 = 0.8

Next shot, go to NL04 = 0.7

May 17 2000 01:01:05:857PM1000517013Brian Labombardshot 13 - FSP scanning
mode B - ASP in fixed mode
NL04 = 0.7

Next shot, repeat with mode A

May 17 2000 01:23:50:653PM1000517014Brian Labombardshot 14 - FSP scanning
mode A - ASP in scanning mode
no plasma

Next shot, try again.

May 17 2000 01:36:42:843PM1000517015Brian Labombardshot 15 - FSP scanning
mode A - ASP in scanning mode
ASP a little over-inserted on .9 sec scan.

Next shot, go to NL04 = 0.5

May 17 2000 02:17:00:590PM1000517017Brian Labombardshot 17 - FSP scanning
mode A - ASP in scanning mode
Good data.

Next shot, repeat NL04 = 0.5 with mode B

May 17 2000 02:42:24:233PM1000517018Brian Labombardshot 18 - FSP scanning
mode B - ASP in fixed mode
Very nice data.

Next shot, go to NL04 = 1.1 with mode B

May 17 2000 02:49:01:483PM1000517018Brian LabombardThe down-stream probes of the Mach probes (east) see much more Isat
fluctuation than the upstream probes (west) when a strong flow
is observed. This is perhaps evidence that the 'wake' of the
probe has a higher turbulence level as plasma attempts to
'fill-in' the wake.
May 17 2000 03:09:10:327PM1000517019Brian Labombardshot 19 - FSP scanning
mode B - ASP in fixed mode
Good data. NL04 = 1.0

Next shot, repeat trying for NL04=1.1, mode A

May 17 2000 03:58:21:123PM1000517022Brian Labombardshot 22 - FSP scanning
mode A - ASP in scanning mode
West power supply is off! East data looks good. NL04 = 1.1

Next shot, try for NL04=1.4, mode A

May 17 2000 04:14:42:937PM1000517023Brian Labombardshot 23 - FSP scanning
mode A - ASP in scanning mode
data look good. NL04 = 1.4

Next shot, repeat in mode B

Physics Operator Comments
May 17 2000 08:52:38:543AMIan HutchinsonMP 267 Dependence of SOL Fluctuations and
Cold Start
Start PCS
Load from 1000516010
C-side PG3 30psi D2; B-top PG4 6psi D2; B-sideLOWER 1psi Ar.

Set Ip to .8MA. TF current to 148kA. In segment 2.
May 17 2000 01:49:50:530PMIan HutchinsonPlasma.

(Accidentally somehow got logged out. Back now)
nl04 to .5e20
May 17 2000 09:13:38:513AM1000517001Ian HutchinsonFizzle. Ip/Bz is way too high. Nice early breakdown. DNB did not open
so the fill is rather low. Bz is too low.

ICEF4 to -1275A from -1290
May 17 2000 09:37:02:857AM1000517002Ian HutchinsonPlasma. Slightly later breakdown, but a good Ip pickup.
nl04=1.e20. Ip 790kA. Gaps fine.

Brian is worried about the separatrix moving away from probe at 1.2s.
Make rcur move out at 1.25s to .665 from .663.
May 17 2000 09:54:03:497AM1000517003Ian HutchinsonPlasma. Unpleasant injection at .88s. Current rise reasonable.

No changes
May 17 2000 10:17:51:170AM1000517004Ian HutchinsonPlasma.

Add Krypton puff on BsideUpper, PG2 2psi 50ms at 1.3-1.35s
May 17 2000 10:35:20:450AM1000517005Ian HutchinsonPlasma. Forgot to enable the Krypton. Do so next shot.
May 17 2000 10:58:20:560AM1000517006Ian HutchinsonFizzle. No obvious magnetics reason. Breakdown slightly late/ragged.

Install EF3 voltage at 300V at 1.4s to see effect of offset.
ICEF4 to -1270
May 17 2000 11:13:51:827AM1000517007Ian HutchinsonPlasma Disrupts at 0.5s. Caused by a monstrous injection.

Return ICEF4 to -1275. Br offset to -.0002
May 17 2000 11:31:36:327AM1000517008Ian HutchinsonFizzle.


Br offset to +.0002. Looks as if it dislikes the negative.
May 17 2000 11:54:40:293AM1000517009Ian HutchinsonPlasma. Disrupts at 1.6s because the Krypton is way too much.

Reduce the krypton puff to 20ms.
Add 2mm to rcur to reduce outer gap by 4mm.
May 17 2000 12:13:08:483PM1000517010Ian HutchinsonFizzle. Looks like a vertical problem at 15ms. Probably we've got too much
field gradient.

OH2V to 25V at .01s (was 16V)
nl04 to .8e20
May 17 2000 12:33:21:340PM1000517011Ian HutchinsonPlasma.

Move the slow zcur gain turn on to 20ms in segment 1.
OH2 to +30V at 7ms.
Kr pulse to 30ms.
Rcur to .669 at 2s
EF3V to +30 at 1.1s and negative in ramp-down.
Rcur to .6665 at .9s
May 17 2000 12:52:36:013PM1000517012Ian HutchinsonPlasma. Saw some reasonable responses to the tweaks.
Krypton is visible; about .1MW on 2pix2.2.


nl04 to .7e20
OH2V to 35V
EF3V to 2480 from 2414 at .01s.
May 17 2000 01:13:01:997PM1000517013Ian HutchinsonPlasma. We've definitely lowered the initial field gradient. zcur looks better.


EF3 more negative (-300V) at 2s.
May 17 2000 01:29:26:810PM1000517014Ian HutchinsonFizzle. Still appears to be a vertical problem at 15ms. Breakdown a little
late but got to 20kA gas current.

OH2s to 45V at 7-10ms.
May 17 2000 02:06:33:153PM1000517015Ian HutchinsonPlasma.

nl04 to .5e20
May 17 2000 02:06:19:997PM1000517016Ian HutchinsonFizzle. Br was very different that shot. And again we seem to have a vertical
problem. Although Ip/Bz hardly reaches 2. Breakdown is late. 6.6ms.

EF3V to 2400V at 10ms.
nl04 .5e20
May 17 2000 02:28:44:780PM1000517017Ian HutchinsonPlasma. Got about 6.e19.

Lower the pg3 V at 200ms to stop overshoot of density.
ICef4 to -1280 from -1275
May 17 2000 02:54:39:437PM1000517018Ian HutchinsonPlasma. Breakdown slightly earlier 5.8ms. That seems to help the current rise.

nl04 to 1.1e20
Drop clearin at about 1.8s because we are going vertically unstable at the
end apparently.
May 17 2000 03:14:51:640PM1000517019Ian HutchinsonPlasma.

Add TF back porch. Raise PG3 V fueling level.
Krypton to 25ms.
Raise nl04 at .3s.
May 17 2000 03:30:20:450PM1000517020Ian HutchinsonFizzle. Gas current does not exceed 10kA. Breakdown is late 6.4ms. Br rather
negative.

Br offset to +.0005
May 17 2000 03:46:32:687PM1000517021Ian HutchinsonFizzle.

V-EF3 to 2300 at 10ms.
Br offset to .0003.
May 17 2000 04:09:33:437PM1000517022Ian HutchinsonPlasma.

EF3 to 2200V at 10ms.
nl04 to 1.4e20
May 17 2000 04:29:22:013PM1000517023Ian HutchinsonPlasma. Disrupts at 1.6s. Extremely slow current initial current rise.
EF1U rails at 1.33s.

Krypton to 5ms.
Ef3V to 2100 at 10ms. Lower Density slightly.
May 17 2000 04:44:59:030PM1000517024Ian HutchinsonFizzle. Ghastly slow current rise.

Lower fill puff to 17ms from 20ms.
May 17 2000 04:53:03:560PM1000517025Ian HutchinsonPlasma disrupts at .27. Too much gas too early.

Try for nl04=.9e20
May 17 2000 05:04:02:763PM1000517026Ian HutchinsonPlasma.

Engineering Operator Comments
ShotTimeTypeStatusComment
108:54:41:483AMPlasmaOk
209:11:37:247AMPlasmaOk
309:35:36:733AMPlasmaOk
409:55:04:467AMPlasmaOk
510:16:19:607AMPlasmaOk
610:39:15:483AMPlasmaOk
710:56:51:450AMPlasmaBadOH1 Self pwrd crkt fired (type 1 flt )
811:15:05:263AMPlasmaOk
911:30:11:077AMPlasmaOk
1011:52:26:327AMPlasmaOk
1112:11:19:873PMPlasmaOk
1212:31:44:123PMPlasmaOk
1312:51:00:610PMPlasmaOk
1401:10:45:937PMPlasmaOk
1501:27:47:450PMPlasmaOk
1601:47:57:903PMPlasmaOk
1702:06:07:140PMPlasmaOk
1802:27:19:873PMPlasmaOk
1902:52:17:170PMPlasmaOk
2003:12:37:670PMPlasmaOk
2103:28:50:700PMPlasmaOk
2203:44:45:950PMPlasmaOk
2304:07:43:903PMPlasmaOk
2404:27:53:357PMPlasmaOk
2504:44:26:997PMPlasmaOk
2605:01:47:873PMPlasmaOk