Alcator C-Mod Run 1000908 Information

Back to runs

Miniproposals
Miniproposal:276
Date Filed: 6/1/2000
Title:Transport Experiments in the Scrape-Off Layer during Ohmic L- andH-mode using Gas-Injection Plumes
First Author:Sanjay Gangadhara
Session Leader:Sanjay Gangadhara (shots 1-25)
Session Leader:Brian Labombard (shots 1-25)

Operators
Session leader(s):Sanjay Gangadhara,Brian Labombard
Physics operator(s):Earl Marmar
Engineering operator(s):Bill Parkin,Gary Dekow

Engineering Operator Run Comment
MP 276 Transport Experiments in the Scrape-Off Layer during Ohmic L- and

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:24:790PM
Author: To Be Determined
Run Plan and Engineering setup for 1000908

MP276 Transport Experiments in the Scrape-Off Layer during
Ohmic L- and H-mode using Gas-Injection Plumes

Session Leader: S. Gangadhara/B. LaBombard
Physics Operator: E. Marmar

Engineering Setup:

Overnight ECDC in D2, stopping 1-2 hours prior to the run.

Run begins at 9:00 and ends at 17:00.

Power system setup as on 1000908001 (0.8 MA, 5.3 T, LSN diverted)

Gas setup - fill B-top with 6 psi of D2 Hybrid enabled
fill B-side lower with 1 psi of Ar Hybrid ENABLED
leave B-side upper as is Hybrid DISABLED
fill C-side with 30 psi of D2 Hybrid enabled
leave J-bottom as is Hybrid DISABLED

The following gate valves should be enabled, assuming no vacuum
problems: ECE, VUV
-------------------------------------------------------------------------

Impurity transport in the scrape-off layer (SOL) is of fundamental
importance in tokamak plasmas. It is clear that the physical processes
involved must be fully characterized and understood in order to
predict core impurity levels in future tokamak reactors. A direct
means of inferring information about impurity transport in the edge
plasma is to inject impurities locally into the SOL through the
``fast-burping'' probe and study the resultant impurity dispersal
patterns (``plumes''). Plumes can yield information about local
parallel and cross-field transport in the edge, as well as information
about local electric field structure.

Experiments will be conducted using deuterated ethylene (C2D4) as the
injected gas, with typically ~ 5 x 10^16 molecules of gas injected per
probe scan. C^+1 (CII) and C^+2 (CIII) emission will be imaged
simultaneously from two near-perpendicular views (F-top, F-side) using
optical systems containing coherent fiber bundles coupled to gated,
intensified CCD cameras through beam-splitter optics and bandpass
interference filters. Experiments will be conducted during ohmic
conditions, to obtain optimal FSP data. We wish to investigate: (1)
the dependence of cross-field spreading (i.e. cross-field transport)
of C^+1 and C^+2 emission at fixed locations in the SOL as a function
of density (or collisionality) during Ohmic L-mode, and (2) the
dependence of cross-field transport on SOL location (rho) for fixed
discharge conditions during both Ohmic L-mode and Ohmic H-mode.

Run Plan:
Day 1: Ohmic L-mode density scan

A density scan will be conducted to determine if plume character varies
with edge collisionality. ``Shallow'' (in the far SOL) and ``Deep'' (near
the separatrix) scans will be conducted to characterize transport variation
with rho.

I_p = 0.8 MA, B_T = 5.3 T

Shot plan:
1-6 NL04=1.0e20, setup FSP target, gas, optimal camera exposures
7-8 NL04=1.0e20, ``shallow'' and ``deep'' FSP insertion, C2D4 plumes
9-11 NL04=0.8e20, ``shallow'' and ``deep'' FSP insertion
12-14 NL04=0.6e20, ``shallow'' and ``deep'' FSP insertion
15 NL04=1.0e20, ``deep'' insertion of FSP
16-18 NL04=1.2e20, ``shallow'' and ``deep'' FSP insertion
19-21 NL04=1.4e20, ``shallow'' and ``deep'' FSP insertion

---------------------------------
Results:

A good day. The first few shots of the day were used to assess
background carbon levels. Gas injection started on shot 4. The probe
was scanned three times during each discharge, at 0.7, 0.9, and 1.1
seconds. Density started at NL04=1.0e20, was reduced to 0.5e20, and
then raised back up to 1.2e20. Injection location varied from rho = 0
mm (right at the separatrix) out to rho = ~ +20 mm at each density. In
the far SOL plumes, cross-field dispersion indicative of ExB flows was
observed in both top and side views for all densities. The dispersion
was relatively uniform along the plume length, consistent with having
small electric fields and long ion lifetimes in this region. Strong
flows to the divertor were also observed in these cases. For plumes
located closer to the separatrix, the nature of the cross-field
dispersion changed to a ``boomeranging''-type character, with dispersion
varying along the plume length. At the highest densities, plumes generated
at the separatrix appeared as though they ``hit a wall'', the cross-field
dispersion being highly asymmetric with most emission located in the
direction away from the separatrix. Parallel flow reversal was also
observed for plumes near the separatrix. Plenty of analysis awaits,
but this run produced plenty of good data to look at.

Physics Operator Summaries
Entered: Jul 7 2004 04:37:11:957PM
Author: To Be Determined
Engineering setup for 1000908:

Overnight ECDC in D2, stopping 1-2 hours prior to the run.

Run begins at 9:00 and ends at 17:00.

Power system setup as on
1000907 (0.8 MA, 5.3 T, LSN diverted)

Gas setup - fill B-top with 6 psi of D2 Hybrid enabled
fill B-side lower with 1 psi of Ar Hybrid ENABLED
leave B-side upper as is Hybrid DISABLED
fill C-side with 30 psi of D2 Hybrid enabled
leave J-bottom as is Hybrid DISABLED

The following gate valves should be enabled, assuming no vacuum problems:
ECE, VUV


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

Run plan for 1000908:

PO: Marmar
EO: Dekow/Parkin
SL: LaBombard/Gangadhara

MP 276 -- Transport Experiments in the Scrape-Off Layer during Ohmic L- and
H-mode using Gas-Injection Plumes

_______________________________________________________________________________

Results:

A boring run from the physop point of view. The machine ran reliably, with
density scans from 0.5e20 to 1.2e20. There was 1 fizzle, probably because B_R
wandered a little bit too negative. The DNB was firing on many shots, but
because they were injecting from 1.4 to 1.5 seconds, the H_2 gas puff doesn't
start until -0.1 seconds, so it had little effect on the pressure at breakdown
(<10%). The probe boys were happily poking and injecting; see the session
leader summary for details. We tested out the silver-doped lithium pellets
(single barrel on shot 15, double barrel on shot 18); both shots disrupted, but
Bob Granetz was disappointed because of the lack of clear thermal quenches.

I fooled around with the ramp-down, and finally got decent survival at high-ish
density on shots 24 and 25.

Shot 1 was inadvertently outboard limited. This was the result of copying
copying waveforms from an old shot, when the offsets were different, for
CLEARIN and RCUR. See the e-mail sent to all physops from Steve Wolfe for details.

There was no RF or between-shot ECDC today.

Scorecard:

24 plasmas
1 fizzle
__
25 data system cycles




----------------------------------------------------------------------------
1000908001 marmar PHYSICS_OPERATOR Sep 8 2000 9:27:36:840AM
. . . . . . . . . . . . . . . . . . . .
loaded from 1000907001

pasted in programming for RCUR, ZCUR, CLEARIN, RXL, ZXL, RXU, ZXU and NL04 from
1000517019

Argon enabled for first shot

plasma

outboard limited
-----------------------------------------------------------------------------
1000908002 marmar PHYSICS_OPERATOR Sep 8 2000 9:34:23:280AM
. . . . . . . . . . . . . . . . . . . .
change RCUR and CLEARIN to fix gaps

lower nl04 prog to 0.9e20

TF current to -150kA in seg 2

plasma
-----------------------------------------------------------------------------
1000908003 marmar PHYSICS_OPERATOR Sep 8 2000 9:50:18:340AM
. . . . . . . . . . . . . . . . . . . .
no PCS changes

plasma

disrupt at 1.3 seconds (too elongated)
-----------------------------------------------------------------------------
1000908004 marmar PHYSICS_OPERATOR Sep 8 2000 10:06:52:890AM
. . . . . . . . . . . . . . . . . . . .
reduce outer gap, RCUR out by 3 mm

plasma

outer gap 1.6 cm
-----------------------------------------------------------------------------
1000908005 marmar PHYSICS_OPERATOR Sep 8 2000 10:44:07:763AM
. . . . . . . . . . . . . . . . . . . .
tweak RCUR after 1.2 seconds

plasma
-----------------------------------------------------------------------------
1000908006 marmar PHYSICS_OPERATOR Sep 8 2000 10:44:20:873AM
. . . . . . . . . . . . . . . . . . . .
no PCS changes

plasma
-----------------------------------------------------------------------------
1000908007 marmar PHYSICS_OPERATOR Sep 8 2000 11:00:46:670AM
. . . . . . . . . . . . . . . . . . . .
DNB enabled for this shot; should fire at 1.4 s

reduce prepuff by 2 ms

tweak rampdown shape

plasma
-----------------------------------------------------------------------------
1000908008 marmar PHYSICS_OPERATOR Sep 8 2000 11:15:40:920AM
. . . . . . . . . . . . . . . . . . . .
add 2 msec back to prepuff

plasma
-----------------------------------------------------------------------------
1000908009 marmar PHYSICS_OPERATOR Sep 8 2000 11:39:20:060AM
. . . . . . . . . . . . . . . . . . . .
add 10 ms to argon puff

shape tweaks after 1.8 seconds

plasma
-----------------------------------------------------------------------------
1000908010 marmar PHYSICS_OPERATOR Sep 8 2000 12:12:00:606PM
. . . . . . . . . . . . . . . . . . . .
RCUR tweaks after 1.2 seconds

plasma
-----------------------------------------------------------------------------
1000908011 marmar PHYSICS_OPERATOR Sep 8 2000 12:12:23:686PM
. . . . . . . . . . . . . . . . . . . .
lower nl04 prog to 7.2e19

plasma
-----------------------------------------------------------------------------
1000908012 marmar PHYSICS_OPERATOR Sep 8 2000 12:44:10:530PM
. . . . . . . . . . . . . . . . . . . .
no PCS changes

plasma
-----------------------------------------------------------------------------
1000908013 marmar PHYSICS_OPERATOR Sep 8 2000 12:45:25:233PM
. . . . . . . . . . . . . . . . . . . .
no PCS changes

plasma
-----------------------------------------------------------------------------
1000908014 marmar PHYSICS_OPERATOR Sep 8 2000 1:28:11:936PM
. . . . . . . . . . . . . . . . . . . .
tweak seg 1 PG3 puff

plasma
-----------------------------------------------------------------------------
1000908015 marmar PHYSICS_OPERATOR Sep 8 2000 1:28:48:686PM
. . . . . . . . . . . . . . . . . . . .
no PCS changes

plasma

silver doped killer pellet at 1.6 seconds -- disrupt
-----------------------------------------------------------------------------
1000908016 marmar PHYSICS_OPERATOR Sep 8 2000 1:50:37:250PM
. . . . . . . . . . . . . . . . . . . .
nl04 prog to 6e19

plasma

density not as low as requested
-----------------------------------------------------------------------------
1000908017 marmar PHYSICS_OPERATOR Sep 8 2000 2:39:03:233PM
. . . . . . . . . . . . . . . . . . . .
reduce PG3 voltage prog in segment 2

reduce nl04 programming early in segment 2

plasma

density still rising during shot
-----------------------------------------------------------------------------
1000908018 marmar PHYSICS_OPERATOR Sep 8 2000 2:39:35:060PM
. . . . . . . . . . . . . . . . . . . .
turn off NINJA helium puff

plasma

got constant density
-----------------------------------------------------------------------------
1000908019 marmar PHYSICS_OPERATOR Sep 8 2000 2:54:01:200PM
. . . . . . . . . . . . . . . . . . . .
nl04 prog to 5e19

reduce PG3 preprog voltage to 0 at .36 seconds

plasma

got the density as requested
-----------------------------------------------------------------------------
1000908020 marmar PHYSICS_OPERATOR Sep 8 2000 3:14:02:140PM
. . . . . . . . . . . . . . . . . . . .
no PCS changes

fizzle
-----------------------------------------------------------------------------
1000908021 marmar PHYSICS_OPERATOR Sep 8 2000 3:32:07:140PM
. . . . . . . . . . . . . . . . . . . .
B_r offset increased by 0.5 mT

plasma
-----------------------------------------------------------------------------
1000908022 marmar PHYSICS_OPERATOR Sep 8 2000 3:50:23:513PM
. . . . . . . . . . . . . . . . . . . .
nl04 prg to 1e20

plasma

got ~9.2e20
-----------------------------------------------------------------------------
1000908023 marmar PHYSICS_OPERATOR Sep 8 2000 4:21:25:623PM
. . . . . . . . . . . . . . . . . . . .
nl04 prog to 1.2e20

fiddle with rampdown (RCUR in farther)

plasma
-----------------------------------------------------------------------------
1000908024 marmar PHYSICS_OPERATOR Sep 8 2000 4:37:28:560PM
. . . . . . . . . . . . . . . . . . . .
tweak ZXL during rampdown

plasma

better rampdown
-----------------------------------------------------------------------------
1000908025 marmar PHYSICS_OPERATOR Sep 8 2000 5:05:02:530PM
. . . . . . . . . . . . . . . . . . . .
no PCS changes

plasma


Session Leader Comments
Sep 8 2000 08:53:43:560AM Run plan for 1000908: MP 276 -- Transport Experiments in the Scrape-Off
Layer during Ohmic L- and H-mode using Gas-Injection Plumes

Day 1: Ohmic L-mode density scan
A density scan will be conducted to determine if plume character varies
with edge collisionality. ``Shallow'' (in the far SOL) and ``Deep'' (near
the separatrix) scans will be conducted to characterize transport variation
with rho.

I_p = 0.8 MA, B_T = 5.3 T

Shot plan:
1-6 NL04=1.0e20, setup FSP target, gas, optimal camera exposures
7-8 NL04=1.0e20, ``shallow'' and ``deep'' FSP insertion, C_2D_4 plumes
9-11 NL04=0.8e20, ``shallow'' and ``deep'' FSP insertion
12-14 NL04=0.6e20, ``shallow'' and ``deep'' FSP insertion
15 NL04=1.0e20, ``deep'' insertion of FSP
16-18 NL04=1.2e20, ``shallow'' and ``deep'' FSP insertion
19-21 NL04=1.4e20, ``shallow'' and ``deep'' FSP insertion
Sep 8 2000 09:26:50:467AM1000908001 BFSP background shot

For the first shot, not firing the probe or injecting gas.
Use to determine background carbon light levels.
PPPL Xybion gates: 0.60 ms, 0.60 ms, 0.60 ms
LANL Xybion gates: 1.05 ms, 1.025 ms, 1.05 ms

Background levels are low, just visible. This indicates
that the exposures are at an appropriate level.

Next shot - didn't quite get Ip = 0.8 MA, NL04 = 1.0e20
Try again, and fire FSP this time.

Sep 8 2000 09:39:54:467AM1000908002 BFSP background shot

Did not fire the probe or inject gas.
Again, use to determine background carbon light levels,
and for conditioning of the ASP.
PPPL Xybion gates: 0.60 ms, 0.60 ms, 0.60 ms
LANL Xybion gates: 1.05 ms, 1.025 ms, 1.05 ms

Very low background levels - can barely be seen.
Was last shot influence of being outboard limited?

Next shot - fire FSP, inject gas, go for a plume!



Sep 8 2000 09:49:38:090AM1000908003 BFSP Injection of C2D4

15.4 torr of C2D4 in FSP plenum

FSP firing at 0.7, 0.9, 1.1 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
shallow insertion of FSP (~ +10 mm)

PPPL Xybion gates (SVC): 0.60 ms, 0.60 ms, 0.60 ms
LANL Xybion gates (TVC): 1.05 ms, 1.05 ms, 1.05 ms
Viewing through CII/CIII beam-splitter

Didn't turn the NINJA trigger on in time, so no
plume for this shot. Did get nice background snaps
with FSP inserted - see significant levels of carbon
light even in this case. May be useful for modelling
of carbon neutral profile.

Next shot - repeat, with NINJA trigger ON for gas
injection.
Sep 8 2000 10:32:14:513AM1000908004 BFSP Injection of C2D4

15.4 torr of C2D4 in FSP plenum

FSP firing at 0.7, 0.9, 1.1 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
medium insertion of FSP (~ +4-6 mm, as LCFS pulls away from probe)

PPPL Xybion gates (SVC): 0.60 ms, 0.60 ms, 0.60 ms
LANL Xybion gates (TVC): 1.05 ms, 1.05 ms, 1.05 ms
Viewing through CII/CIII beam-splitter

Great data on both cameras! Can slightly increase PPPL
gates, because pixel values are near ~ 190. Saturation
on LANL camera at probe head, and good values for CIII
just outside of the probe head. CII levels are slightly
lower on this camera, but still okay. Raise last exposure
for this camera because images were slightly dimmer.

Next shot - repeat, with slightly modified exposures.
Sep 8 2000 10:33:17:733AM1000908005 BFSP Injection of C2D4

15.3 torr of C2D4 in FSP plenum

FSP firing at 0.7, 0.9, 1.1 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
medium insertion of FSP (~ +4-6 mm, as LCFS pulls away from probe)

PPPL Xybion gates (SVC): 0.70 ms, 0.70 ms, 0.70 ms
LANL Xybion gates (TVC): 1.05 ms, 1.05 ms, 1.15 ms
Viewing through CII/CIII beam-splitter

Good data. For PPPL data, first scan is somewhat diffuse,
second scan is good (evidence of boomeranging), and third
scan is completely diffuse. Gas injection levels may be
too low, and last scan in general has lowest gas injected.
Values for pixels are again < ~ 190 or so.

For LANL data, data is good. CII levels are again slighty
lower, but good. Emission is much more symmetric than in
side view.

Next shot - increase gas in plenum, and decrease exposures
accordingly.
Sep 8 2000 10:55:31:340AM1000908006 BFSP Injection of C2D4

17.6 torr of C2D4 in FSP plenum

FSP firing at 0.7, 0.9, 1.1 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"medium" insertion of FSP (~ +4-6 mm, as LCFS pulls away from probe)

PPPL Xybion gates (SVC): 0.55 ms, 0.60 ms, 0.60 ms
LANL Xybion gates (TVC): 1.00 ms, 1.00 ms, 1.05 ms
Viewing through CII/CIII beam-splitter

Good PPPL data! First two scans have good data. Last
scan the exposure was somewhat high - turn down exposure.

For first two scans of LANL data, exposures were apparently
too low - didn't get out of the background. For last scan
exposure was too high - got "blasted". Difference is small
between these exposures - may have to do with changing
plasma conditions?

Next shot - move probe out additional +5 mm, generate plumes
in far SOL. Change exposures to try and compensate.
Sep 8 2000 11:08:31:953AM1000908007 BFSP Injection of C2D4

17.5 torr of C2D4 in FSP plenum

FSP firing at 0.7, 0.9, 1.1 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"shallow" insertion of FSP (~ +9-11 mm, as LCFS pulls away from probe)

PPPL Xybion gates (SVC): 0.55 ms, 0.55 ms, 0.55 ms
LANL Xybion gates (TVC): 1.00 ms, 1.00 ms, 1.00 ms
Viewing through CII/CIII beam-splitter.

Good PPPL data! Again, first two scans of LANL camera
were low. Realized that that was because the first
two scans were really at 0.1 ms, not 1.0 ms! Typo in
widget. Based on last scan, exposures were slightly
high, so will reduce them for next shot.

Next shot - try again, in far SOL, with proper exposures.
Sep 8 2000 11:19:53:903AM1000908008 BFSP Injection of C2D4

17.4 torr of C2D4 in FSP plenum

FSP firing at 0.7, 0.9, 1.1 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"shallow" insertion of FSP (~ +9-11 mm, as LCFS pulls away from probe)

PPPL Xybion gates (SVC): 0.55 ms, 0.55 ms, 0.55 ms
LANL Xybion gates (TVC): 0.85 ms, 0.85 ms, 0.85 ms
Viewing through CII/CIII beam-splitter.

Great PPPL data! Near saturation, but not saturated.
Plumes look rather wide.

LANL data is good. Got some saturation near the probe
head. Plumes look narrow (in cross-field direction),
comparable to plumes we saw at "medium" insertion.

Next shot - deep scan (target +2 mm), and change
exposures accordingly.
Sep 8 2000 11:37:45:780AM1000908009 BFSP Injection of C2D4

17.3 torr of C2D4 in FSP plenum

FSP firing at 0.7, 0.9, 1.1 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"deep" insertion of FSP (~ +2-4 mm, as LCFS pulls away from probe)

PPPL Xybion gates (SVC): 0.50 ms, 0.50 ms, 0.50 ms
LANL Xybion gates (TVC): 0.70 ms, 0.70 ms, 0.70 ms
Viewing through CII/CIII beam-splitter.

Good data on both cameras. Neither reached saturation,
and PPPL camera had slightly low signal. Some small
evidence of boomeranging on side view, but no dramatic
difference in plume structure.

Next shot - go in even deeper, and see if we see
any changes.
Sep 8 2000 12:01:58:497PM1000908010 BFSP Injection of C2D4

17.3 torr of C2D4 in FSP plenum

FSP firing at 0.7, 0.9, 1.1 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"very deep" insertion of FSP (~ +0-2 mm, as LCFS pulls away from probe)

PPPL Xybion gates (SVC): 0.50 ms, 0.50 ms, 0.50 ms
LANL Xybion gates (TVC): 0.60 ms, 0.60 ms, 0.60 ms
Viewing through CII/CIII beam-splitter.

Good data. Exposures were slightly low, especially for
LANL camera, but still get good signal-to-noise. For
first two scans we were right at separatrix, and see
difference in plume structure. From side view, it is as
if plume "hits a wall" - very diffuse below injection,
and steep decrease above injection. From top view, still
seems symmetric up-down, but narrower. Good for comparison
with previous data.

Next shot - decrease density by 20% (NL01 ~ 0.8e20). Inject
in "medium" SOL (~ +5 mm) and adjust exposures accordingly.
Sep 8 2000 12:18:00:670PM1000908011 BFSP Injection of C2D4

17.2 torr of C2D4 in FSP plenum

FSP firing at 0.7, 0.9, 1.1 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"medium" insertion of FSP (~ +4-6 mm, as LCFS pulls away from probe)

PPPL Xybion gates (SVC): 0.60 ms, 0.60 ms, 0.60 ms
LANL Xybion gates (TVC): 0.80 ms, 0.80 ms, 0.80 ms
Viewing through CII/CIII beam-splitter.

Good data on both views! PPPL has slightly low exposure,
and the LANL camera slightly high exposure. Stronger
evidence for boomeranging in side view (possibly different
E fields or because density is lower so that ionization
lifetimes are higher). Top view looks narrower than at
higher density.

Next shot - inject deeper (~ +10 mm), and adjust exposures
accordingly.
Sep 8 2000 12:35:14:920PM1000908012 BFSP Injection of C2D4

17.1 torr of C2D4 in FSP plenum

FSP firing at 0.7, 0.9, 1.1 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"shallow" insertion of FSP (~ +10-12 mm, as LCFS pulls away from probe)

PPPL Xybion gates (SVC): 0.65 ms, 0.65 ms, 0.65 ms
LANL Xybion gates (TVC): 0.80 ms, 0.80 ms, 0.80 ms
Viewing through CII/CIII beam-splitter.

Great data on both cameras. Exposures may be slightly
low for LANL camera, but still good. Still see strong
boomeranging on side view, and plume centroid may be
slightly lower than at previous insertion depth. No
noticeable difference in top view (awaiting further
analysis...)

Next shot - go out even further in SOL (~ +15 mm)
Sep 8 2000 12:55:15:857PM1000908013 BFSP Injection of C2D4

17.1 torr of C2D4 in FSP plenum

FSP firing at 0.7, 0.9, 1.1 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"very shallow" insertion of FSP (~ +15-17 mm, as LCFS pulls away from probe)

PPPL Xybion gates (SVC): 0.70 ms, 0.70 ms, 0.70 ms
LANL Xybion gates (TVC): 0.85 ms, 0.85 ms, 0.85 ms
Viewing through CII/CIII beam-splitter.

Great data on both views. Asymmetries seen in emission
from side and top view which would indicate that the
impurities are "ExB-flowing" along the flux surface
where they are injected. Exposures are good.

Next shot - go right to the separatrix (~ +0 mm) and adjust
exposures accordingly.
Sep 8 2000 01:14:53:500PM1000908014 BFSP Injection of C2D4

16.9 torr of C2D4 in FSP plenum

FSP firing at 0.7, 0.9, 1.1 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"very deep" insertion of FSP (~ +0-2 mm, as LCFS pulls away from probe)

PPPL Xybion gates (SVC): 0.55 ms, 0.55 ms, 0.55 ms
LANL Xybion gates (TVC): 0.70 ms, 0.70 ms, 0.70 ms
Viewing through CII/CIII beam-splitter.

For first scan, plume again looks like it "hits a wall",
especially from side view. Top view is completely saturated
for this scan. On second scan there is more dispersal,
and lower intensity, and on third scan plumes look very
dispersed. Rho is changing with scans, but not sure what
else could be creating these dramatic differences.

Next shot - pull probe out ~ +0.5 mm (saw some arcing on
first scan), and adjust exposures so that no saturation
occurs on any scan.
Sep 8 2000 01:31:32:090PM1000908015 BFSP Injection of C2D4

16.8 torr of C2D4 in FSP plenum

FSP firing at 0.7, 0.9, 1.1 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"very deep" insertion of FSP (~ +0-2 mm, as LCFS pulls away from probe)

PPPL Xybion gates (SVC): 0.450 ms, 0.515 ms, 0.55 ms
LANL Xybion gates (TVC): 0.500 ms, 0.575 ms, 0.70 ms
Viewing through CII/CIII beam-splitter.

Good data, but exposures were low. Looks like we didn't
get close enough to separatrix to hit the wall. Still
have interesting data - on third scan see asymmetries
in both views again indicative of ExB flows.

Next shot - lower density to 0.6e20, probe far out in
SOL, and adjust exposures accordingly.
Sep 8 2000 01:56:42:450PM1000908016 BFSP Injection of C2D4

16.7 torr of C2D4 in FSP plenum

FSP firing at 0.7, 0.9, 1.1 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"very shallow" insertion of FSP (~ +15-17 mm, as LCFS pulls away from probe)

PPPL Xybion gates (SVC): 0.75 ms, 0.75 ms, 0.75 ms
LANL Xybion gates (TVC): 0.90 ms, 0.90 ms, 0.90 ms
Viewing through CII/CIII beam-splitter.

Good data on both cameras. Plume is near the bottom of
the side view - we are really far out in the SOL. See
a very skewed emission on both side and top views,
primarily in CIII emission. CII emission is more symmetric.
Exposures are good - a little low for top view, but also
have saturation near the probe head.

Next shot - insert probe deeper (~ +7-8 mm)

Sep 8 2000 02:16:12:110PM1000908017 BFSP Injection of C2D4

16.6 torr of C2D4 in FSP plenum

FSP firing at 0.7, 0.9, 1.1 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"medium" insertion of FSP (~ +7-9 mm, as LCFS pulls away from probe)

PPPL Xybion gates (SVC): 0.70 ms, 0.70 ms, 0.70 ms
LANL Xybion gates (TVC): 0.85 ms, 0.85 ms, 0.85 ms
Viewing through CII/CIII beam-splitter.

Good data. Exposures on top camera are slightly low. See
definite boomeranging on side view, both CII and CIII
emission. Emission from top view is still asymmetrically
skewed, but not as dramatically.

Next shot - up to separatrix.

Sep 8 2000 02:38:51:310PM1000908018 BFSP Injection of C2D4

16.5 torr of C2D4 in FSP plenum

FSP firing at 0.7, 0.9, 1.1 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"very deep" insertion of FSP (~ +0-2 mm, as LCFS pulls away from probe)

PPPL Xybion gates (SVC): 0.65 ms, 0.675 ms, 0.675 ms
LANL Xybion gates (TVC): 0.80 ms, 0.825 ms, 0.850 ms
Viewing through CII/CIII beam-splitter.

Good data on both cameras, with low exposures on LANL
camera. Strong boomeranging on side view. Slight skewedness
on top view, but camera distortion needs to be taken out.
No "wall" is apparent.

Next shot - go down in density somewhat more (have been
around 0.65-0.70e20 the last few shots) and probe far in
SOL.

Sep 8 2000 03:02:59:763PM1000908019 BFSP Injection of C2D4

16.5 torr of C2D4 in FSP plenum

FSP firing at 0.7, 0.9, 1.1 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"very shallow" insertion of FSP (~ +20-22 mm, as LCFS pulls away from probe)
NL04 = 0.5e20

PPPL Xybion gates (SVC): 0.775 ms, 0.775 ms, 0.775 ms
LANL Xybion gates (TVC): 0.915 ms, 0.915 ms, 0.915 ms
Viewing through CII/CIII beam-splitter.

Great data on both cameras. See large "fan" of asymmetry
on top view, similar to "very shallow" plume from 0.65e20
shot (shot 16). Good case where CII emission can be used
as source for CIII modelling, because plumes are large
enough, and in side view see definite "downward" transport
(ExB?) of impurities.

Next shot - same density, insert slightly deeper.
Sep 8 2000 03:11:30:000PM1000908020 BFSP Injection of C2D4

16.4 torr of C2D4 in FSP plenum

FSP firing at 0.7, 0.9, 1.1 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"very shallow" insertion of FSP (~ +20-22 mm, as LCFS pulls away from probe)
NL04 = 0.5e20

PPPL Xybion gates (SVC): 0.750 ms, 0.750 ms, 0.750 ms
LANL Xybion gates (TVC): 0.935 ms, 0.935 ms, 0.935 ms
Viewing through CII/CIII beam-splitter.

Fizzle. Try again.
Sep 8 2000 03:37:35:263PM1000908021 BFSP Injection of C2D4

16.4 torr of C2D4 in FSP plenum

FSP firing at 0.7, 0.9, 1.1 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"very shallow" insertion of FSP (~ +20-22 mm, as LCFS pulls away from probe)
NL04 = 0.5e20

PPPL Xybion gates (SVC): 0.750 ms, 0.750 ms, 0.750 ms
LANL Xybion gates (TVC): 0.935 ms, 0.935 ms, 0.935 ms
Viewing through CII/CIII beam-splitter.

Good data, with low light levels. This seems to be primarily
because of the "wispy", dispersed nature of the emission.
Very low light levels on scan 3.

Next shot - go back to NL04=1.0e20, and poke in far SOL.
Sep 8 2000 03:53:34:043PM1000908022 BFSP Injection of C2D4

16.2 torr of C2D4 in FSP plenum

FSP firing at 0.7, 0.9, 1.1 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"very shallow" insertion of FSP (~ +20-22 mm, as LCFS pulls away from probe)
NL04 = 1.0e20

PPPL Xybion gates (SVC): 0.575 ms, 0.575 ms, 0.575 ms
LANL Xybion gates (TVC): 0.850 ms, 0.850 ms, 0.850 ms
Viewing through CII/CIII beam-splitter.

Great data on both cameras. Good pixel levels. See
"fanning" action again in top view. Side view indicates
flow to the divertor.

Next shot - increase density again, to 1.2e20, and stay
at this location.
Sep 8 2000 04:19:50:903PM1000908023 BFSP Injection of C2D4

16.1 torr of C2D4 in FSP plenum

FSP firing at 0.7, 0.9, 1.1 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"very shallow" insertion of FSP (~ +20-22 mm, as LCFS pulls away from probe)
NL04 = 1.2e20

PPPL Xybion gates (SVC): 0.525 ms, 0.525 ms, 0.525 ms
LANL Xybion gates (TVC): 0.825 ms, 0.825 ms, 0.825 ms
Viewing through CII/CIII beam-splitter.

Good data on both cameras. See STRONG flow to the
divertor, and strong fanning-action on the top view.
On top view, plumes get weaker from scan to scan,
possibly due to rising density. Similar result on
side view.

Next shot - probe in deeper.
Sep 8 2000 04:36:47:437PM1000908024 BFSP Injection of C2D4

16.1 torr of C2D4 in FSP plenum

FSP firing at 0.7, 0.9, 1.1 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"deep" insertion of FSP (~ +3-5 mm, as LCFS pulls away from probe)
NL04 = 1.2e20

PPPL Xybion gates (SVC): 0.515 ms, 0.515 ms, 0.515 ms
LANL Xybion gates (TVC): 0.800 ms, 0.800 ms, 0.800 ms
Viewing through CII/CIII beam-splitter.

Good data. Top view is near saturation. Seem to see
flow to the divertor, and little asymmetry (looks
strongest on last scan). From side view, it looks
like flow reversal, so we have to be careful about
this. Very dispersed in this view ("wispy"), but
good pixel values.

Next shot - intermediate probe depth.
Sep 8 2000 04:59:07:170PM1000908025 BFSP Injection of C2D4

16.0 torr of C2D4 in FSP plenum

FSP firing at 0.7, 0.9, 1.1 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"medium" insertion of FSP (~ +9-11 mm, as LCFS pulls away from probe)
NL04 = 1.2e20

PPPL Xybion gates (SVC): 0.525 ms, 0.525 ms, 0.525 ms
LANL Xybion gates (TVC): 0.810 ms, 0.810 ms, 0.810 ms
Viewing through CII/CIII beam-splitter.

Great data! Some saturation on LANL camera, but small.
Second and third scans exhibit flow to the divertor,
and fanning-action/skewedness, but this is not so
apparent in first scan. Not clear what changed in that
time. Lots of data to chew on.

End of run.

Physics Operator Comments
Sep 8 2000 08:48:44:310AMEarl MarmarEngineering setup for 1000908:

Overnight ECDC in D2, stopping 1-2 hours prior to the run.

Run begins at 9:00 and ends at 17:00.

Power system setup as on 1000907001 (0.8 MA, 5.3 T, LSN diverted)

Gas setup - fill B-top with 6 psi of D2 Hybrid enabled
fill B-side lower with 1 psi of Ar Hybrid ENABLED
leave B-side upper as is Hybrid DISABLED
fill C-side with 30 psi of D2 Hybrid enabled
leave J-bottom as is Hybrid DISABLED

The following gate valves should be enabled, assuming no vacuum problems:
ECE, VUV


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

Run plan for 1000908:

MP 276 -- Transport Experiments in the Scrape-Off Layer during Ohmic L- and
H-mode using Gas-Injection Plumes
Sep 8 2000 08:50:25:920AMEarl Marmarcoldstart

CAMAC error, no Q

Ran ccl remcam

reran coldstart

no errors; all matrices respond
Sep 8 2000 09:27:36:840AM1000908001Earl Marmarloaded from 1000907001

pasted in programming for RCUR, ZCUR, CLEARIN, RXL, ZXL, RXU, ZXU and NL04 from 1000517019

Argon enabled for first shot

plasma

outboard limited
Sep 8 2000 09:34:23:280AM1000908002Earl Marmarchange RCUR and CLEARIN to fix gaps

lower nl04 prog to 0.9e20

TF current to -150kA in seg 2

plasma
Sep 8 2000 09:50:18:340AM1000908003Earl Marmarno PCS changes

plasma

disrupt at 1.3 seconds (too elongated)
Sep 8 2000 10:06:52:890AM1000908004Earl Marmarreduce outer gap, RCUR out by 3 mm

plasma

outer gap 1.6 cm
Sep 8 2000 10:44:07:763AM1000908005Earl Marmartweak RCUR after 1.2 seconds

plasma
Sep 8 2000 10:44:20:873AM1000908006Earl Marmarno PCS changes

plasma
Sep 8 2000 11:00:46:670AM1000908007Earl MarmarDNB enabled for this shot; should fire at 1.4 s

reduce prepuff by 2 ms

tweak rampdown shape

plasma
Sep 8 2000 11:15:40:920AM1000908008Earl Marmaradd 2 msec back to prepuff

plasma
Sep 8 2000 11:39:20:060AM1000908009Earl Marmaradd 10 ms to argon puff

shape tweaks after 1.8 seconds

plasma
Sep 8 2000 12:12:00:607PM1000908010Earl MarmarRCUR tweaks after 1.2 seconds

plasma
Sep 8 2000 12:12:23:687PM1000908011Earl Marmarlower nl04 prog to 7.2e19

plasma
Sep 8 2000 12:44:10:530PM1000908012Earl Marmarno PCS changes

plasma
Sep 8 2000 12:45:25:233PM1000908013Earl Marmarno PCS changes

plasma
Sep 8 2000 01:28:11:937PM1000908014Earl Marmartweak seg 1 PG3 puff

plasma
Sep 8 2000 01:28:48:687PM1000908015Earl Marmarno PCS changes

plasma

silver doped killer pellet at 1.6 seconds -- disrupt
Sep 8 2000 01:50:37:250PM1000908016Earl Marmarnl04 prog to 6e19

plasma

density not as low as requested
Sep 8 2000 02:39:03:233PM1000908017Earl Marmarreduce PG3 voltage prog in segment 2

reduce nl04 programming early in segment 2

plasma

density still rising during shot
Sep 8 2000 02:39:35:060PM1000908018Earl Marmarturn off NINJA helium puff

plasma

got constant density
Sep 8 2000 02:54:01:200PM1000908019Earl Marmarnl04 prog to 5e19

reduce PG3 preprog voltage to 0 at .36 seconds

plasma

got the density as requested
Sep 8 2000 03:14:02:140PM1000908020Earl Marmarno PCS changes

fizzle
Sep 8 2000 03:32:07:140PM1000908021Earl MarmarB_r offset increased by 0.5 mT

plasma
Sep 8 2000 03:50:23:513PM1000908022Earl Marmarnl04 prg to 1e20

plasma

got ~9.2e20
Sep 8 2000 04:21:25:623PM1000908023Earl Marmarnl04 prog to 1.2e20

fiddle with rampdown (RCUR in farther)

plasma
Sep 8 2000 04:37:28:560PM1000908024Earl Marmartweak ZXL during rampdown

plasma

better rampdown
Sep 8 2000 05:05:02:530PM1000908025Earl Marmarno PCS changes

plasma

Engineering Operator Comments
ShotTimeTypeStatusComment
109:03:32:170AMPlasmaOk
209:28:56:200AMPlasmaOk
309:43:13:090AMPlasmaOk
409:56:56:513AMPlasmaOk
510:15:51:450AMPlasmaOk
610:36:31:373AMPlasmaOk
710:53:31:060AMPlasmaOk
811:08:55:687AMPlasmaOk
911:28:17:140AMPlasmaOk
1011:46:58:217AMPlasmaOk
1112:06:11:437PMPlasmaOk
1212:23:41:140PMPlasmaOk
1312:43:37:700PMPlasmaOk
1401:00:05:060PMPlasmaOk
1501:22:16:403PMPlasmaOk
1601:43:57:530PMPlasmaOk
1702:04:44:500PMPlasmaOk
1802:26:49:403PMPlasmaOk
1902:47:36:640PMPlasmaOk
2003:08:19:403PMPlasmaOk
2103:24:15:780PMPlasmaOk
2203:46:00:810PMPlasmaOk
2304:06:29:937PMPlasmaOk
2404:26:56:170PMPlasmaOk
2504:46:11:093PMPlasmaOk