Alcator C-Mod Run 1040414 Information

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Miniproposals
Miniproposal:393
Date Filed: 4/1/2004
Title:Magnetic fluctuations associated with edge plasma turbulence
First Author:Brian Labombard
Session Leader:Brian Labombard (shots 1-37)

Operators
Session leader(s):Brian Labombard
Physics operator(s):Steve Wolfe
Engineering operator(s):Gary Dekow

Engineering Operator Run Comment
MP#393 Magnetic fluctuations; SL:LaBombard; PO:Wolfe; EO:Dekow/Parkin

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:04:867PM
Author: Brian Labombard
Run Summary for 1040414
MP#393 "Magnetic fluctuations associated with edge plasma turbulence"

Physics Operator: S. Wolfe
Session Leader: B. LaBombard
______________________________________________________________________________
Purpose:
The purpose is to characterize broad-band magnetic fluctuations
associated with plasma turbulence in the vicinity of the magnetic separatrix.

We will use the two-coil magnetic probe head installed on the A-port drive (ASP)
to record poloidal magnetic field fluctuations (frequency and k-poloidal
resolved) as a function of depth in the scrape-off layer. We are specifically
interested in looking for changes in the character of magnetic fluctuations
in ohmic L-mode as the edge plasma collisionality is changed.

Plan:
The key diagnostics which must be operational for this study are:
A-port scanning probe (with double magnetic probe head) and F-port scanning probe.

Start with a reload of shot#1040326019 which ran as a lower single-null,
Ip = 0.8 MA, Bt = 5.4 tesla discharge with N04 = 0.86e20.
Set ASP rest position to +14mm, FSP to -4 mm and scanning at 0.6, 0.8, 1.0 seconds.

Shot#1,2
NL04 = 0.9 set up probe targets

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

Shot#4-14: NL04 = 0.9, 0.7, 0.5, 1.1, 1.3, 1.5

Allow for some repeated shots.

If time allows, we may want to run a couple of shots in upper null topology to
see if the poloidal phase velocities of the magnetic perturbations track with changes
in edge plasma toroidal rotation.
______________________________________________________________________________
Result:
This was a very productive run. We got an excellent density scan from NL04 = 0.3e20
to NL04 = 1.7e20 in lower-null discharges (Ip = 0.8MA, Bt = 5.4 tesla). We started off
trying to alternate between having the ASP (magnetic probe) in a scanning and dwell (fixed-location)
mode. But it became apparent that the probe was spewing in some gas (plus crud) in dwell
mode. Also, the magnetic signals were weak in dwell mode. So we kept the probe
scanning on the rest of the shots and did a fine density scan instead (steps of approx NL04 = 0.1e20).
The magnetic probe signals were very clean and we were able to look at frequency and
wavenumber resolved fluctuation spectra during the run. Some systematic differences
were seen as a function of density and depth into the SOL.
As a bonus, we were also able to take data in upper single-null discharges (shots 23-29).
The magnetic data clearly showed a reduced poloidal phase velocity (i.e., not as strong in the
electron diamagnetic direction) in these discharges compared to similar ones in lower single
null. Perhaps the difference is related to a reduced pressure gradient near the separatrix
which has been noted previously in probe profile data.
This run completed all goals in MP#393.
______________________________________________________________________________

Shot log:

01- SNL, NL04=0.98, ASP(+15), FSP(-4), ISP, data ok
02- no TF
03- SNL, NL04=1.14, ASP(+13,dwell scan trig=.8), FSP(-3), ISP
04- early disruption
05- early disruption
06- SNL, NL04=0.9, ASP(+15), FSP(-3), ISP
07- SNL, NL04=0.9, ASP(+15), FSP(+1), ISP - excellent data
08- SNL, NL04=0.77, ASP(+15), FSP(+1), ISP - nice data
09- SNL, NL04=0.72, ASP(+14), FSP(-1), ISP - nice data
10- SNL, NL04=0.63, ASP(+14), FSP(-1), ISP
11- SNL, NL04=0.5, ASP(+12), FSP(-3), ISP
12- SNL, NL04=0.4, ASP(+12), FSP(-2), ISP
13- SNL, NL04=0.3, ASP(+12), FSP(-2), ISP
14- SNL, NL04=0.95, ASP(+12), FSP(-2), ISP
15- no power shot
16- SNL, NL04=1.15 to 1.2, ASP(+12), FSP(-2), ISP
17- SNL, NL04=1.1, ASP(+12), FSP(0), ISP
=> disrupts right after 1st scan
18- SNL, NL04=1.2 to 1.3, ASP(+11), FSP(-2)
19- SNL, NL04=1.3, 1.5, 1.6, ASP(+11), FSP(-1)
20- SNL, NL04=1.4, 1.5, 1.65, ASP(+12), FSP(0)
21- no power shot
22- SNL, NL04=1.4, 1.5, 1.65, ASP(+12), FSP(+2)
23- SNU, NL04=0.9 ASP(+6.5), FSP(+8.5)
24- SNU, NL04=1.1 ASP(+8.5), FSP(+9.5)
25- SNU, NL04=0.7 ASP(+8.5), FSP(+9.5)
26- SNU, NL04=0.5 ASP(+8.5), FSP(+9.5)
27- early disruption
28- early disruption
29- SNU, NL04=0.6, 0.54, 0.48 ASP(+8.5), FSP(+9.5)

Physics Operator Summaries
Entered: Jul 7 2004 04:36:49:863PM
Author: Steve Wolfe
Physics Operator Summary for 1040414

MP#393 "Magnetic fluctuations associated with edge plasma turbulence"
SL: LaBombard
followed by (time permitting)
MP#386 "locked mode thresholds"
SL: Hutchinson

PO: Wolfe
EO: Dekow,Byford

ECDC overnight (D2)

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

Power systems the same as 1040326019

A-coils should be configured as on 1040331001 (+Dtop -Dbot -Jtop +Jbot), 3kA,
600V, enabled.

Gas setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar Hybrid enabled (PG1)
leave B-side upper with 15 psi He3 Hybrid disabled (not connected)
fill C-side with 30 psi D2 Hybrid enabled (PG3)
fill J-side with 30 psi D2 Hybrid disabled (PG2)
Disable NINJA

Enable the following gate valves, assuming no vacuum problems:
ECE, VUV, DNB

-------------------------------------------------------------------------------
RF Setup: RF in RunOn by 9:00AM so Wukie can run some test piggyback shots for
VTang ( a late addition to the plan).


-------------------------------------------------------------------------------
Run Plan for MP#393:

The purpose is to characterize broad-band magnetic fluctuations
associated with plasma turbulence in the vicinity of the magnetic separatrix.

We will use the two-coil magnetic probe head installed on the A-port drive (ASP)
to record poloidal magnetic field fluctuations (frequency and k-poloidal
resolved) as a function of depth in the scrape-off layer. We are specifically
interested in looking for changes in the character of magnetic fluctuations
in ohmic L-mode as the edge plasma collisionality is changed.

The key diagnostics which must be operational for this study are:
A-port scanning probe (with double magnetic probe head) and F-port scanning probe.

Start with a reload of shot#1040326019 which ran as a lower single-null,
Ip = 0.8 MA, Bt = 5.4 tesla discharge with N04 = 0.86e20.
Set ASP rest position to +14mm, FSP to -4 mm and scanning at 0.6, 0.8, 1.0 seconds.

Shot#1,2
NL04 = 0.9 set up probe targets

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

Shot#4-14: NL04 = 0.9, 0.7, 0.5, 1.1, 1.3, 1.5

Allow for some repeated shots.

If time allows, we may want to run a couple of shots in upper null topology to
see if the poloidal phase velocities of the magnetic perturbations track with changes
in edge plasma toroidal rotation.


---------------------------------------------
If time allows, proceed to the final "three" shots required to complete (??) Ian's
locked mode threshold experiments at 1MA:

1. Load 1MA shot from 1040317 and reduce density to nebar~4.5e19/m^3
(nl04~2.6e19) with acoil current =1000A.

2. Same density, run acoil current of 3500A

3. Reverse Acoil current to "-1200A" and go to density nebar=2.3e20
(nl04=1.4e20)


*******************************************************************
Results
------

A pretty good run day. Brian got all of his MP393 done, and then some, completing
a density scsn from 3e19 1.1) in an upper null configuration. The upper null was loaded from seg 3 of
1040213006, with reprogrammed density. He turned the run over to the second MP
at ~15:10, after shot#29.

Getting to low density under feedback control was quite successful. I adjusted
the pg3 feedforward in seg2 as I changed the nl04 request and was able to get
pretty much what I asked for. Even the 3e19 800kA case still had some gas puff
going. During the last shot in Ian's part of the run I dropped the nl04 P gain
from 8 to 4, which seemed to reduce the oscillations in the gas puff and
steady the density. It helped that we went in the direction of decreasing
density on these sequences, so that the walls were unloading. It was also
necessary (?) to increase the pg4 puff in seg 1 to keep the breakdown
good. The lowest density points in the MP393 run had moderate runaways,
building up some during the shot. Ian's shots, at even lower density, had
large, saturating hard xray levels.

On the low density shots#11, 12, and 13 RF and DNB fired late in the pulse so
Vincent could check his signals and noise in preparation for tomorrow's
run. There were H-modes at quite low density on #11 and 12; on #13 the RF
reduced power and the density was even lower (nl4=3e19) and there was no
H-mode. These discharges should be evaluated in terms of the "low density
H-mode limit".

The locked mode MP#386 was not as successful. We started with fizzles and
early disruptions (and finished that way too). Only 3 useful plasmas (and 5
fizzles or disruptions) were produced in this part of the run. Attempts to
refine the threshold of point #1 only provided a lower bound of 500A, (shots
#33 and 36 were unlocked). However, this was enough information to cast doubt
on the validity of the straight line relation of nebar vs B21_app, as the
expectation was that the 1000A case would lock. The high acoil current case#2
(shot#35) appeared to have a locked mode at acoil current of 3500A, although
the signature was less than clear; basically only the magnetics signals seemed
to have a transition, while the sawteeth and nl04 had no obvious breaks. We
did not attempt a lower positive current to refine the threshold in the region
of point#2. We did not get to try the high density, adverse current case #3.

There were a number of early disruptions, apparently associated with
injections near segment switch, OH crowbar, and/or OH1 crossover, early in the
run and again late in the day. No solution was found; we basically just ended
up waiting for the machine to clean up again. There were also two
computer-related no power shots, and one no TF shot (the usual unexplained
failure) on shot#2. On one of the no power shots (#15) the magnetics data from
shot 14 was stored again because the cpci did not get initialized.

The first (and last) attempt by Brian to dwell the ASP on shot#3 seemed to
cause excess fueling from the probe, as the density went considerably higher
than programmed with the gas valve off after .38sec. Aftr that Brian decided
to use the ASP only in scan mode, and we did the density scan at intervals of
0.1e20 instead of 0.2e20.

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

Tests/NoPower 2
Duds (no TF) 1
fizzles 3
Early disruption 6 (0.1 Plasmas 25
============ ==
Shots 37




Session Leader Comments
Apr 14 2004 09:07:24:583AM1040414001Brian LabombardShot 01 FSP, ASP, ISP scanning at .65, .85. 1.05
NL04=.98
ASP - double magnetic probe head
FSP - ok, could be deeper, data ok
ISP - shorted electrode
Apr 14 2004 09:39:14:693AM1040414003Brian LabombardShot 03 FSP, ISP scanning at .65, .85. 1.05
ASP dwelling, trig=0.8s
NL04=1.14
ASP - double magnetic probe head
FSP - ok, could be deeper, data ok
ISP - shorted electrode
Apr 14 2004 10:19:55:007AM1040414006Brian LabombardShot 06 FSP, ASP, ISP scanning at .65, .85. 1.05
NL04=.9
ASP - double magnetic probe head
FSP - ok, could be deeper, data ok
ISP - shorted electrode
Apr 14 2004 10:28:19:817AM1040414007Brian LabombardShot 07 FSP, ASP, ISP scanning at .75, .95. 1.15
NL04=.9
ASP - double magnetic probe head - nice signals
FSP - excellent data
ISP - shorted electrode
Apr 14 2004 10:43:48:340AM1040414008Brian LabombardShot 08 FSP, ASP, ISP scanning at .75, .95. 1.15
NL04=.77
ASP - double magnetic probe head - nice signals
FSP - excellent data - getting deep
ISP - shorted electrode
Apr 14 2004 10:57:41:970AM1040414009Brian LabombardShot 09 FSP, ASP, ISP scanning at .75, .95. 1.15
NL04=.72
ASP - double magnetic probe head - nice signals
FSP - excellent data
ISP - shorted electrode
Apr 14 2004 11:17:26:970AM1040414010Brian LabombardShot 10 FSP, ASP, ISP scanning at .75, .95. 1.15
NL04=.63
ASP - double magnetic probe head - nice signals
FSP - excellent data - getting deep again
ISP - shorted electrode
Apr 14 2004 11:30:15:193AM1040414011Brian LabombardShot 11 FSP, ASP, ISP scanning at .75, .95. 1.15
NL04=.5
ASP - double magnetic probe head - nice signals
FSP - excellent data - deep but ok
ISP - shorted electrode
Apr 14 2004 11:47:31:343AM1040414012Brian LabombardShot 12 FSP, ASP, ISP scanning at .75, .95. 1.15
NL04=.4
ASP - double magnetic probe head - nice signals
FSP - excellent data - deep
ISP - shorted electrode
Apr 14 2004 12:03:26:713PM1040414013Brian LabombardShot 13 FSP, ASP, ISP scanning at .75, .95. 1.15
NL04=.3
ASP - double magnetic probe head - ok
FSP - ok
ISP - shorted electrode
Apr 14 2004 12:03:52:197PM1040414014Brian LabombardShot 14 FSP, ASP, ISP scanning at .75, .95. 1.15
NL04=.95
ASP - double magnetic probe head - ok
FSP - ok, could be deeper
ISP - shorted electrode
Apr 14 2004 12:40:37:397PM1040414016Brian LabombardShot 16 FSP, ASP, ISP scanning at .75, .95. 1.15
NL04=1.15 to 1.2
ASP - double magnetic probe head - ok
FSP - ok, could be deeper
ISP - shorted electrode
Apr 14 2004 12:47:01:250PM1040414017Brian LabombardShot 17 FSP, ASP, ISP scanning at .75, .95. 1.15
NL04=1.0, disrupts after first scan
ASP - double magnetic probe head - ok
FSP - ok
ISP - shorted electrode
Apr 14 2004 01:02:55:303PM1040414018Brian LabombardShot 18 FSP, ASP, ISP scanning at .75, .95. 1.15
NL04=1.2 to 1.3
ASP - double magnetic probe head - ok
FSP - ok, would like it to be deeper
ISP - shorted electrode
Apr 14 2004 01:30:37:830PM1040414019Brian LabombardShot 19 FSP, ASP scanning at .75, .95. 1.15
NL04=1.3, 1.5, 1.6
ASP - double magnetic probe head - ok
FSP - ok, try for deeper
Apr 14 2004 01:30:58:597PM1040414020Brian LabombardShot 20 FSP, ASP scanning at .75, .95. 1.15
NL04=1.4, 1.5, 1.65
ASP - double magnetic probe head - ok
FSP - ok, try for deeper
Apr 14 2004 01:52:07:863PM1040414022Brian LabombardShot 22 FSP, ASP scanning at .75, .95. 1.15
NL04=1.4, 1.5, 1.58
ASP - double magnetic probe head - ok
FSP - ok
Apr 14 2004 02:06:20:527PM1040414023Brian LabombardShot 23 USN, FSP, ASP scanning at .75, .95. 1.15
NL04=.88
ASP - double magnetic probe head - ok, could be deeper
FSP - nice
Apr 14 2004 02:29:14:987PM1040414025Brian LabombardShot 25 USN, FSP, ASP scanning at .75, .95. 1.15
NL04=0.7
ASP - double magnetic probe head - ok
FSP - nice
Apr 14 2004 03:22:06:287PM1040414029Brian LabombardShot 29 USN, FSP, ASP scanning at .75, .95. 1.15
NL04=0.6, .54, .48
ASP - double magnetic probe head - ok
FSP - nice

Physics Operator Comments
Apr 14 2004 06:53:04:580AMSteve WolfeEngineering setup for Wednesday 14-Apr-2004

MP#393 "Magnetic fluctuations associated with edge plasma turbulence"
SL: LaBombard
followed by (time permitting)
MP#386 "locked mode thresholds"
SL: Hutchinson

PO: Wolfe

ECDC overnight on Sunday (D2)

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

Power systems the same as 1040326019

A-coils should be configured as on 1040331001 (+Dtop -Dbot -Jtop +Jbot), 3kA,
600V, enabled.

Gas setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar Hybrid enabled (PG1)
leave B-side upper with 15 psi He3 Hybrid disabled (not connected)
fill C-side with 30 psi D2 Hybrid enabled (PG3)
fill J-side with 30 psi D2 Hybrid disabled (PG2)
Disable NINJA

Enable the following gate valves, assuming no vacuum problems:
ECE, VUV, DNB

-------------------------------------------------------------------------------
RF Setup: NO RF Required

-------------------------------------------------------------------------------
Run Plan for MP#393:

The purpose is to characterize broad-band magnetic fluctuations
associated with plasma turbulence in the vicinity of the magnetic separatrix.

We will use the two-coil magnetic probe head installed on the A-port drive (ASP)
to record poloidal magnetic field fluctuations (frequency and k-poloidal
resolved) as a function of depth in the scrape-off layer. We are specifically
interested in looking for changes in the character of magnetic fluctuations
in ohmic L-mode as the edge plasma collisionality is changed.

The key diagnostics which must be operational for this study are:
A-port scanning probe (with double magnetic probe head) and F-port scanning probe.

Start with a reload of shot#1040326019 which ran as a lower single-null,
Ip = 0.8 MA, Bt = 5.4 tesla discharge with N04 = 0.86e20.
Set ASP rest position to +14mm, FSP to -4 mm and scanning at 0.6, 0.8, 1.0 seconds.

Shot#1,2
NL04 = 0.9 set up probe targets

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

Shot#4-14: NL04 = 0.9, 0.7, 0.5, 1.1, 1.3, 1.5

Allow for some repeated shots.

If time allows, we may want to run a couple of shots in upper null topology to
see if the poloidal phase velocities of the magnetic perturbations track with changes
in edge plasma toroidal rotation.


---------------------------------------------
If time allows, proceed to the final "three" shots required to complete (??) Ian's
locked mode threshold experiments at 1MA:

1. Load 1MA shot from 1040317 and reduce density to nebar~5e19/m^3 (nl04~3e19)
with acoil current =1000A.

2. Same density, run acoil current of 3500A

3. Reverse Acoil current to "-1200A" and go to density nebar=2.3e20
(nl04=1.4e20)
Apr 14 2004 06:59:07:450AMSteve WolfePCS setup for 1040414:

Load from 1040326019 (all segs)
Decrease pg4 puff from 18msec to 14msec
Keep br0=0, ic_ef4=-1335

note nl04=.85; I'm not sure from Blab's run plan if he wants this
raised to .90 or not, so leave it for now.

Load at 14-Apr-2004 06:58:22.00
Open tree /home/wolfe/pcs_scratch -1
Open tree done
Apr 14 2004 07:27:41:367AMSteve WolfePCS setup for 1040414:

The reference shot 1040326019 has RF; it also seems to
have the A-coils disabled, although the program is
there for a 2500A pulse. I'll check with Brian to see
if he wants them on or off.

Apr 14 2004 08:28:55:680AMSteve WolfeBrian says he does want nl04=.9 on the first shot.
Change nl04 program to 9.5e19, and program pg3 for 30V maintenance level
Load at 14-Apr-2004 08:28:45.00
Open tree /home/wolfe/pcs_scratch -1
Open tree done
Apr 14 2004 09:01:51:870AM1040414001Steve Wolfeshot#1: plasma full length. Got closer to 1 than .9

next shot: drop nl04 demand back down to 8.8e19
Apr 14 2004 09:07:11:600AM1040414001Steve Wolfeshot#1: plasma full length. Got closer to 1 than .9
A few early runaways. small injection after 1.4sec

next shot: drop nl04 demand back down to 8.8e19
Apr 14 2004 09:15:18:157AM1040414002Steve Wolfeshot#2: drop nl04 demand back down to 8.8e19
move rcur out by 1.5mm at 1.5s, 0.8mm at 1.0s,
trying to flatten the outer gap trace.

NO TF.
Apr 14 2004 09:39:37:553AM1040414003Steve Wolfeshot#3: Try again.
drop nl04 demand back down to 8.8e19
move rcur out by 1.5mm at 1.5s, 0.8mm at 1.0s,
trying to flatten the outer gap trace.

plasma disrupts at 1.4sec; small runaway dump at .1sec
density too high, around 1.2e20. No problem on tci, gas is off after .38sec
Are we fueling from the probe??

next shot: back to scanning mode, out another 1.5mm on rcur


Apr 14 2004 09:46:40:190AM1040414004Steve Wolfeshot#4: back to scanning mode, out another 1.5mm on rcur at 1.5sec

Short disruption, 135ms; injection around 50msec,

next shot: raise pg4 to 16msec
Apr 14 2004 10:00:57:527AM1040414005Steve Wolfeshot#5: raise pg4 to 16msec
disrupts at .33sec
More injections. Still some runaways.

next shot: Raise pg4 again, tweak early ip program
Apr 14 2004 10:09:36:007AM1040414006Steve Wolfeshot#6: : Raise pg4 to 18ms, tweak early ip from 700 to 650@0.1sec
plasma; almost lose it .12sec, big marfe early then recovers.

next shot: reduce early nl04 rise, and seg1 pg3.
Apr 14 2004 10:28:07:927AM1040414007Steve Wolfeshot#7: nl04 rise to 0.4sec, and seg1 pg3 down to 50V
move rcur point at 1 sec out by 1.5mm

plasma full length, no marfe, no current glitch
Looks good.

next shot- down to 0.8e19
Apr 14 2004 10:43:39:747AM1040414008Steve Wolfeshot#8: nl04 from .88 to .78, pg3 seg 2 from 30 to 15V
plasma full length,
nl4=7.6 to 7.8e19, looks good except for injections at the probe sweeps
and at crossover around 0.5sec

next shot: down to 0.7e20
Apr 14 2004 10:52:46:450AM1040414009Steve Wolfeshot#9: nl04 down to 0.7e20; raise pg4 to 20msec
plasma full length nl04~0.7e20, some wobbles.
looks like some dithers on Halpha around 1sec and 1.5sec

next shot: down to 0.6e20

Apr 14 2004 11:08:11:347AM1040414010Steve Wolfeshot#10: nl04 down to 0.6e20; pg3 maint level off
plasma full length, 6e19

next shot: down to 5e19

Apr 14 2004 11:22:11:883AM1040414011Steve Wolfeshot#11: nl04 down to 0.5e20; pg3 seg 2 off completely
RF will fire late for Vincent. Beam time adjusted.

plasma full length, 5e19. H-mode at 1.21sec when the RF comes on
Got E and J, no D

next shot: down to 4e19
Apr 14 2004 11:37:59:720AM1040414012Steve Wolfeshot#12: nl04 down to 4e19
plasma full length, 4e19; hmode at 1.22sec or so
Still no D-port; E and J ok.

next shot: go to 0.3
Apr 14 2004 11:48:32:330AM1040414013Steve Wolfeshot#13: nl04 down to 3e19 !
plasma full length, nl04=3e19; no h-mode
still no d-port.

next shot: nl04=1e20
Apr 14 2004 12:01:46:007PM1040414014Steve Wolfeshot#14:nl04 to 1e20 and pg3 to 30V maint after 50V early seg2
plasma full length, nl4=.97e20

next shot: 1.1e20
Apr 14 2004 12:16:06:327PM1040414015Steve Wolfeshot#15:nl04 to 1.1e20 and pg3 to 40V maint after 50V early seg2

No power shot -- Data system/tree not found problem
Magnetics data from previous shot!

Seems to have been something T&J did by mistake?
Expect next shot to be ok?
Apr 14 2004 12:23:51:590PM1040414016Steve Wolfeshot#16:nl04 to 1.1e20 and pg3 to 40V maint after 50V early seg2
plasma full length, nl04=1.25e20; too much maintenance gas?

next shot: drop the maintenance down to 15V, decrease pg4 puff
Apr 14 2004 12:39:48:080PM1040414017Steve Wolfeshot#17:drop the maintenance down to 15V, decrease pg4 puff from 20->16msec
plasma disrupted at .7861, injection at .75 on the probe poke
nl04 was 1.0, so I should probably increase the maint level to 25V

next shot: raise pg3 maint to 25V
Apr 14 2004 12:58:39:690PM1040414018Steve Wolfeshot#18: raise pg3 maint to 25V, raise nl04 to 1.3
plasma to 1.85sec, nl4=1.3 with some wobulation.
Pokes could be doing a little fueling.

next shot: 1.4
Apr 14 2004 01:08:55:250PM1040414019Steve Wolfeshot#19:nl4 to 1.4e20 at .5sec; early point from .4 to .5e20
plasma to 1.85sec, nl4 between 1.4 and 1.7e20; looks like may have been fueled
by the second poke.

next shot: repeat
Apr 14 2004 01:24:10:993PM1040414020Steve Wolfeshot#20: repeat, except drop pg4 from 16 to 14msec
plasma to 1.85sec nl4 from 1.4 to 1.7e20

next shot: repeat
Apr 14 2004 01:36:06:310PM1040414020Steve Wolfeshot#21: repeat with slightly different probe targeting
Data system hangs in init

No power shot.
Apr 14 2004 01:47:20:480PM1040414022Steve Wolfeshot#22: repeat of 20 with slightly different probe targeting
plasma to 1.8sec, similar to 20

next shot: upper null
Apr 14 2004 02:01:59:270PM1040414023Steve Wolfeshot#23: load from 1040213006 (seg 3 uupper null)
reload seg1 from 1040414022
nl04 change to 0.9e20, pg3 maint to 25V
ip[0.1] from 600->650kA
Got one factor message in load

plasma full length, nl04=8.9e19

next shot: go to 1.1e20

Apr 14 2004 02:13:46:850PM1040414024Steve Wolfeshot#24: go to nl04=1.1e20
plasma full length, almost lost it at .1 with a big current glitch
early marfe.
nl04 ok at 1.1e20

next shot: go down to 0.7e20
Apr 14 2004 02:27:44:233PM1040414025Steve Wolfeshot#25: drop nl04 to 0.7e20,pg3 maint to 15V
Change first zcur point to -.003 from -.009
pg4 to 16ms

plasma full length, nl4=7->6e19
glitch at .1 is gone, still some crossover thrash.

next shot: 0.5e20
Apr 14 2004 02:45:45:933PM1040414026Steve Wolfeshot#26: drop nl04 to 0.5e20,pg3 maint to 0, most of early seg2 pg3 off
Eliminate rcur point near crossover time

plasma full length, nl04=5->4e19
big CII excursion in startup, nearly lost it.

next shot: pg4 to 19ms. nl04 to 0.6
Apr 14 2004 02:59:51:940PM1040414027Steve Wolfeshot#27: nl04 to 0.7e20,pg4 to 19ms from 16
short disruption, the glitch at seg switch came back

next shot: just repeat
Apr 14 2004 03:07:55:623PM1040414028Steve Wolfeshot#28: just repeat
And it did, disrupts at 300msec
This is like what happened at the start of the day on 4,5,and 6?

next shot: try one more

Apr 14 2004 03:18:38:063PM1040414029Steve Wolfeshot#29: try one more

plasma full length. mnl04=5e19, some early glitches

End of MP393.

next shot: Go to Ian's shots
Apr 14 2004 03:32:13:600PM1040414030Steve Wolfeshot#30: Import seg2 from 1040317025 (1MA SNL from Ian's run)
reduce nl04 to 2.6e19, drop pg3 maint to 0
Program acoil to 1500A

fizzle. pressure may be a touch high

next shot: repeat
Apr 14 2004 03:48:48:923PM1040414031Steve Wolfeshot#31: repeat for Ian's condition#1
early disruption. Current turns around at .1sec,
recovers, then disrupts at .3, runaway dump at the disruption

next shot: drop ip[.1] from 700->600kA, reduce rcur near crossover
Apr 14 2004 03:55:50:200PM1040414032Steve Wolfeshot#32: drop ip[.1] from 700->600kA, reduce rcur near crossover
fizzle.

next shot: drop pg4 to 17msec
Apr 14 2004 04:14:06:617PM1040414033Steve Wolfeshot#33: drop pg4 to 17msec, while I'm at it reduce seg1 pg3 to 40V
plasma full length,
nl04=2.3 falling to 1.5e19; acoil at 1000A
NO LOCKED Mode; not the expected result.

Next shot: Raise Acoil current to 4000A for condition 2
Apr 14 2004 04:17:47:997PM1040414033Steve Wolfeshot#34: drop pg4 to 17msec, while I'm at it reduce seg1 pg3 to 40V
plasma full length,
nl04=2.3 falling to 1.5e19; acoil at 1000A
NO LOCKED Mode; not the expected result.

Next shot: Raise Acoil current to 4000A for condition 2
Apr 14 2004 04:27:54:230PM1040414034Steve Wolfeshot#34: Raise Acoil current to 4000A for condition 2,move late pg3 to +10Vfrom negative
early disruption. .25sec

next shot: repeat

Apr 14 2004 04:42:43:160PM1040414035Steve Wolfeshot#35: Repeat Acoil current to 4000A for condition 2,move late pg3 to 10V from negative
plasma full length, 2 possible locked mode at .7sec based on magnetics.
Not visible on ece or nl04

next shot: Acoil to 500A,
Apr 14 2004 04:54:23:400PM1040414036Steve Wolfeshot#36: Acoil to 500A, reduce P gain on nl04 from 8 to 4
Another try for case 1 at lower acoil current

plasma full length, some runaways
less oscillation on 1.8 No locked mode

next shot: Turn off acoil
Apr 14 2004 05:04:42:193PM1040414037Steve Wolfeshot#37: Acoil to 0A
Another try for case 1 as intrinsic

fizzle
CO2 had a glitch too, so the feedback probably wouldn't have worked anyway

END OF RUN

Engineering Operator Comments
ShotTimeTypeStatusComment
108:57:21:193AMPlasmaOk
209:13:02:920AMPlasmaBadNo TF on this Shot
309:25:20:393AMPlasmaOk
409:41:01:103AMPlasmaOk
509:53:29:450AMPlasmaOk
610:06:19:660AMPlasmaOk
710:19:05:160AMPlasmaOk
810:35:02:187AMPlasmaOk
910:47:50:673AMPlasmaOk
1011:00:50:850AMPlasmaOk
1111:16:34:470AMPlasmaOk
1211:29:33:537AMPlasmaOk
1311:43:47:447AMPlasmaOk
1411:56:19:983AMPlasmaOk
1512:09:44:550PMPlasmaBadNo Data System
1612:19:47:050PMPlasmaOk
1712:32:12:773PMPlasmaOk
1812:50:58:490PMPlasmaOk
1901:04:23:070PMPlasmaOk
2001:16:52:450PMPlasmaOk
2201:43:39:147PMPlasmaOk
2301:56:30:323PMPlasmaOk
2402:09:35:720PMPlasmaOk
2502:22:16:210PMPlasmaOk
2602:36:53:937PMPlasmaOk
2702:49:29:283PMPlasmaOk
2803:02:13:710PMPlasmaOk
2903:14:58:587PMPlasmaOk
3003:28:14:343PMPlasmaOk
3103:40:43:550PMPlasmaOk
3203:53:25:147PMPlasmaOk
3304:06:13:200PMPlasmaOk
3404:20:55:253PMPlasmaOk
3504:33:42:943PMPlasmaOk
3604:47:27:887PMPlasmaOk
3705:00:36:093PMPlasmaOk