Alcator C-Mod Run 1000915 Information

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: Brian Labombard (shots 1-29)

Session Leader: Sanjay Gangadhara (shots 1-29)

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

Engineering Operator Run Comment
MP 276 Transport Experiment SL:Gangadhara/LaBomvard PO:Snipes EO:Dekow/P

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Entered: Jul 7 2004 03:49:24:883PM

Author: To Be Determined

Run Plan and Engineering setup for 1000915

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: J. Snipes

Engineering setup for Friday, 15 September 2000:

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

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

Power system setup as on 1000829018

Gas setup - fill B-top with 6 psi of D2 Hybrid enabled
fill B-side lower with 1 psi of Ar Hybrid enabled
fill B-side upper with 35 psi of He Hybrid DISABLED (Yes, HELIUM)
(available for between-shot ECDC)
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 2: Ohmic H-mode

At constant discharge conditions, the depth of injection will be varied
to determine transport variation with cross-field coordinate (rho) during
H-mode. Timing of the injection will also be varied to catch various phases
in the discharge, e.g. L-mode, L-H transition, ELM-free H-mode, EDA H-mode.

Set-up B-field ramp so as to obtain Ohmic H-mode
plasmas similar to 1000518022, but staying at I_p = 0.8 MA.
Start with NL04 = 0.8e20/m^2.

Shot plan:
1-6 Setup FSP target, gas, optimal camera exposures
7-12 Vary FSP timing, inject into far SOL (> ~ +15 mm)
13-17 Vary FSP timing, inject into near SOL (< ~ +3 mm)
18-20 Vary FSP timing, inject near and past separatrix

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

A good day, though we didn't quite follow the run plan as scheduled.
The first shot of the day was used to assess background carbon levels,
with gas injection starting on shot 2. The first part of the run was
used to investigate plumes generated at various scrape-off layer depths
during ELM-free H-mode. For many of these discharges the probe was
scanned only once, to ensure that during that scan the probe reached
its desired target in the scrape-off layer. Injection timing was also
varied to ensure catching the H-mode phase. No clear differences in the
cross-field plume structure were seen for these cases. One explanation
is that though the electric field is varying strongly as the injection
depth varies, the local electron density and temperature, and hence the
ionization lifetime for the impurities, is also varying strongly, and
thus these two effects on cross-field dispersion are effectively
cancelling. In contrast, the parallel structure of the plumes seemed
to change with injection depth, and parallel flow reversal was evident
for plumes closer to the separatrix. Further analysis is required.

The second part of the run was dedicated to studying plumes close to
the separatrix for both ELM-free and EDA phases. In general, plumes
generated in EDA exhibited less cross-field dispersal than plumes in
ELM-free phases. For a plume generated during the EDA H-mode phase on
shot 23, the cross-field dispersal of the plume was indicative of an
inward directed radial electric field. This is the first time this has
been observed with the plumes. Unfortunately, the probe experienced
serious arcing during this time, and probe data may not be useful. The
probe was switched to a double-probe mode for the remainder of the run
to alleviate this problem. However, this cross-field behaviour was not
reproduced, though there was some evidence of the plumes experiencing
shearing due to being generated in a region of radial electric field
reversal. One reason the full reversal of the plume dispersion is not
being seen consistently has been tracked down, and involves the camera
exposure timing being late relative to the probe injection timing. This
issue has been sorted out. With radial electric field reversal having
now been observed, further collection of plume data near the separatrix
is desired. That data could then be used as a tool for understanding the
behaviour of the radial electric field structure near the separatrix.
This also would serve as a useful cross-calibration of probe measurements
of the local electric field.

Physics Operator Summaries

Entered: Jul 7 2004 04:37:12:037PM

Author: To Be Determined

Engineering setup for Friday, 15 September 2000:

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

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

Power system setup as on 1000829018

Gas setup - fill B-top with 6 psi of D2 Hybrid enabled
fill B-side lower with 1 psi of Ar Hybrid enabled
fill B-side upper with 35 psi of He Hybrid DISABLED (Yes, HELIUM)
(available for between-shot ECDC)
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

We only got two hours of ECDC before the run because of a mixup. There was
also a problem with the hybrid this morning because the A matrix did not
respond to the coldstart. However, thanks to an e-mail from Steve Wolfe, a ccl
remcam resolved the problem. Apparently, SPANNA had been rebooted and did not
have the correct definitions prior to the ccl remcam.

Summary: It was a very good run with several shots with peaked density H-modes
most notably shots 1, 6, and 19. We also independently verified the density
threshold that Amanda found yesterday for the ELM-free/EDA boundary. It is
still at 0.6 x 10^20 m^-2 for nl04 programming even at low field with Ohmic
H-mode rather than RF H-mode. The probe studies also went well. See the
session leader's summary for the plume results. The machine ran very well,
though we did have a few unexplained disruptions and some resulting fizzles.

Shot,Duration(s),Ipmax(MA) Shot,Duration(s),Ipmax
1 1.923 0.814 2 1.919 0.814
3 1.403 0.809 4 0.000 0.037
5 1.471 0.812 6 1.927 0.814
7 1.924 0.814 8 1.929 0.810
9 1.932 0.809 10 0.000 0.034
11 1.933 0.809 12 1.919 0.812
13 1.921 0.814 14 1.916 0.809
15 1.923 0.809 16 1.919 0.809
17 1.918 0.809 18 1.922 0.809
19 1.923 0.812 20 1.368 0.807
21 1.920 0.809 22 1.271 0.810
23 1.920 0.812 24 1.924 0.809
25 0.891 0.809 26 1.460 0.812
27 0.000 0.037 28 1.922 0.812
29 1.178 0.817
Finished summary for 1000915 Total of 29 shots.
29 shots. 26 plasmas. 3 fizzles. 0 duds.

Shot 1: Copied shot 1000829018 despite the changes in EFIT, which may mean we
will have to change the gaps somewhat to get what we want. Good shot.
Nice long H-mode of varying flavors.
Shot 2: Put in an additional ramp in ZXL by 15 mm from 0.8 to 1.4 s, then held
constant to 1.5 s to give the FSP a constant target. Good shot. FSP
target still not right. Brian wants to double the ramp rate for the
next shot.
Shot 3: Increased ramp rate to ramp another 15 mm from 0.8 to 1.4 s in ZXL and
then held constant until 1.5 s. Good shot. Disrupted at 1.5 s
apparently because the ZXL ramp was too far.
Shot 4: Reduced ZXL ramp by 7 mm. Increased RCUR by 2 mm to reduce the outer
gap as well. Reduced nl04 from 6.5 to 6.0 x 10^19 m^-2. Fizzle!
Shot 5: Sparker did not have as high a current as on shot 4. Try again with 2 ms less pre-puff.
Good shot. Disrupted again at 1.5 s. FSP target still not quite flat.
Shot 6: Try flattening out the FSP target with a triangle in the ZXL program
at about 1.1 s. Then, reduce the ramp further out past 1.2 sec to try
to avoid pushing things too hard and causing a disruption. Changed
Br0 from 0.5 mT to 1 mT to try to avoid another fizzle, though the
disruption may cause a fizzle regardless.
Shot 7: Change Br0 from 1 mT to 1.5 mT to try to preempt a possible fizzle.
Good shot.
Shot 8: Ramped Bt up faster and removed the flat in Bt around 1.2 s to try to
get out of ELM-free H-mode and into EDA H-mode faster to avoid impurity
buildup that leads to the L-H transition at about 1.0 s. Good shot.
Shot 9: Raised nl04 to 6.5 x 10^19 m^-3 to try to get a longer EDA H-mode.
Good shot.
Shot 10: Try between shot ECDC before this shot to see if we can improve the
quality of the H-mode. Also, disabling the Ar puff to see if it
is increasing the radiation. Returning to 6.0 x 10^19 m^-2. Fizzle!
I suspect the gas pressure did not get low enough to get breakdown
after the ECDC was turned off. Try again without ECDC before the shot.
Shot 11: One more time without ECDC before this shot. Good shot. Still did
not get the long EDA phase we wanted.
Shot 12: Try cutting off the return Bt ramp up at 1.0 s to see if we can keep
the EDA longer by keeping the H-mode threshold lower for longer to
avoid the Type III ELMy regime. Re-enabled the Ar puff. Good shot.
Still did not get a long EDA H-mode though.
Shot 13: Try cutting off the TF 0.1 s earlier because of delays in the change
in the TF relative to the programming. Good shot. ELM-free phase
integrates up the impurities, then collapses into L-mode, then returns
into a long EDA phase.
Shot 14: Try increasing nl04 to 6.5 x 10^19 m^-2. Excellent shot! Long EDA
H-mode from 0.88 - 1.5 s. Brian is still not happy. Picky, picky,
picky! Nice peaked density H-mode though.
Shot 15: Try nl04 = 6.25 x 10^19 m^-2 and pull in on RXU by another 1.5 cm to
increase the upper triangularity. Good shot. ELM-free with transition
then long EDA phase.
Shot 16: Tweak nl04 up to 6.3 x 10^19 m^-2. Increase upper triangularity some
more by decreasing RXU by another 1.5 cm from 0.65 s to 1.4 s. Too
much! The upper X point touches the inner wall and keeps the plasma
in L-mode throughout the shot.
Shot 17: Bring RXU back by 1.5 cm to about what it was on shot 15 and try again.
Good shot. Brief ELM-free then L-mode then long EDA H-mode.
Shot 18: Changed RXU from -0.035 to -0.03 m to slightly lower the upper
triangularity. Good shot. Nice long EDA from 0.89 - 1.57 s.
Shot 19: Brian is still not happy. Reduce nl04 to 6.1 x 10^19 m^-2. Excellent
shot. ELM-free phase early, then suddenly becomes EDA with no L-mode
phase in between. The H-mode lasts from 0.88 - 1.53 s.
Shot 20: Repeat. Disrupted at 1.35 s. A spike on the bolometers at 1.2 s
indicates that the probe may have caused the plasma to drop out of
H-mode and perhaps led to the disruption as well.
Shot 21: Repeat. Good shot. ELM-free, then L-mode, then long EDA phase.
Shot 22: Raise nl04 to 6.2 x 10^19 m^-2. Disrupted again at 1.26 s at the probe
injection time.
Shot 23: Repeat. Good shot. Two ELM-free H-modes. We have apparently found the
same density threshold for the ELM-free/EDA boundary that Amanda found
yesterday in RF H-modes at about 0.6 x 10^20 m^-2 on nl04, which
corresponds to about 1.3 x 10^20 m^-3 on NEBAR_EFIT.
Shot 24: Increase nl04 to 6.5 x 10^19 m^-2. Good shot.
Shot 25: Decrease nl04 to 6.0 x 10^19 m^-2 to ensure ELM-free H-mode. Disruption
at 0.88 s before first probe scan. Bolometer increases dramatically
at 0.86 s, which leads to a large oscillating MHD mode, which then
locks and disrupts right afterward. The probe guys will not take
credit for this one. Perhaps it was an injection of some UFO.
Shot 26: Repeat. Disrupted at 1.46 s. Probe guys do not take credit for this
one either. Big impurity injection at 0.82 s. Finally enters H-mode
at 1.08 s, then had a large H-L transition at 1.4 s, which took a bite
out of the current and led to the disruption.
Shot 27: Repeat. Fizzle!
Shot 28: Took 2 ms off of the pre-puff to 20 ms duration. Try again.
Good shot.
Shot 29: Repeat. Disrupted at 1.1 s. There were several injections that the
probe guys do not take credit for that I think led to the final
disruption.

Session Leader Comments

Sep 15 2000 08:38:28:390AM Run plan for 1000915: MP 276 -- Transport Experiments in the Scrape-Off
Layer during Ohmic L- and H-mode using Gas-Injection Plumes

Run Day 2: Ohmic H-mode

At constant discharge conditions, the depth of injection will be varied
to determine transport variation with cross-field coordinate (rho) during
H-mode. Timing of the injection will also be varied to catch various phases
in the discharge, e.g. L-mode, L-H transition, ELM-free H-mode, EDA H-mode.

Set-up B-field ramp so as to obtain Ohmic H-mode
plasmas similar to 1000518022, but staying at I_p = 0.8 MA.
Start with NL04 = 0.8e20/m^2.

Shot plan:
1-6 Setup FSP target, gas, optimal camera exposures
7-12 Vary FSP timing, inject into far SOL (> ~ +15 mm)
13-17 Vary FSP timing, inject into near SOL (< ~ +3 mm)
18-20 Vary FSP timing, inject near and past separatrix

Sep 15 2000 09:21:48:873AM 1000915001 BFSP background shot

For the first shot, not firing the probe or injecting gas.
Use to determine background carbon light levels, for
setting exposures.

Exposures taken at: 0.7, 0.9, 1.1 sec
PPPL Xybion gates (SVC): 0.65 ms, 0.65 ms, 0.65 ms
LANL Xybion gates (TVC): 0.85 ms, 0.85 ms, 0.85 ms

Very low levels of emission on each view.

Good discharge! Got H-mode around 0.9 seconds,
and EDA around 1.1 seconds.

Next shot - change FSP timings slightly to make
sure we catch the H-mode phases, and inject.

Sep 15 2000 11:50:05:983AM 1000915002 BFSP Injection of C2D4

17.0 torr of C2D4 in FSP plenum

FSP firing at 0.75, 0.95, 1.15 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): 0.85 ms, 0.85 ms, 0.85 ms
Viewing through CII/CIII beam-splitter

Good data. Exposures were somewhat low, especially for
LANL camera. Second scan is good ELM-free H-mode, and
plumes from both views are very, very diffuse in nature.
Third scan is in some sort of EDA, with dithering in Dalpha.
Plumes are less diffuse in this case.

Next shot - increase exposures, try and flatten FSP target.

Sep 15 2000 10:14:59:030AM 1000915003 BFSP Injection of C2D4

16.9 torr of C2D4 in FSP plenum

FSP firing at 0.75, 0.95, 1.15 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"shallow" insertion of FSP (~ +10-12 mm)

PPPL Xybion gates (SVC): 0.75 ms, 0.80 ms, 0.75 ms
LANL Xybion gates (TVC): 1.00 ms, 1.15 ms, 1.10 ms
Viewing through CII/CIII beam-splitter

Good data. Similar to last shot, and increasing exposures
helped. Saw some saturation on CII at probe head from
top view. Plumes during second scan are more spread than
during third scan (it seems), but more intense as well -
may have to do with slightly higher exposure.

Next shot - repeat, modify exposures slighty, lower density
slightly to try and make sure ELM-free phase is solidly
ELM-free.

Sep 15 2000 10:15:29:013AM 1000915004 BFSP Injection of C2D4

16.9 torr of C2D4 in FSP plenum

FSP firing at 0.75, 0.95, 1.15 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"shallow" insertion of FSP (~ +10-12 mm)

PPPL Xybion gates (SVC): 0.85 ms, 0.85 ms, 0.85 ms
LANL Xybion gates (TVC): 1.05 ms, 1.10 ms, 1.10 ms
Viewing through CII/CIII beam-splitter

Fizzle. Try again next shot.

Sep 15 2000 11:49:45:857AM 1000915005 BFSP Injection of C2D4

16.8 torr of C2D4 in FSP plenum

FSP firing at 0.75, 0.95, 1.15 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"deep" insertion of FSP (~ +0-2 mm)

PPPL Xybion gates (SVC): 0.85 ms, 0.85 ms, 0.85 ms
LANL Xybion gates (TVC): 1.00 ms, 1.10 ms, 1.10 ms
Viewing through CII/CIII beam-splitter

Good data. First scan hits the separatrix, and this
is apparent on the plumes - they look very thin from
the top, and as though they "hit a wall" on the side.
Next two scans are H-modes, further out. First one
ELM-free, and second one EDA-ish. Again, we can see
difference in plume widths, with ELM-free plumes
exhibiting less cross-field spreading in the field
of view.

Next shot - pull FSP out some (saw arcing on first scan)
and change timings slightly, to catch L-H transition.
Also, change exposures slightly.

Sep 15 2000 11:49:54:607AM 1000915006 BFSP Injection of C2D4

16.6 torr of C2D4 in FSP plenum

FSP firing at 0.65, 0.90, 1.15 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"deep" insertion of FSP (~ +0-2 mm)

PPPL Xybion gates (SVC): 0.85 ms, 0.85 ms, 0.90 ms
LANL Xybion gates (TVC): 1.00 ms, 1.10 ms, 1.15 ms
Viewing through CII/CIII beam-splitter

Good data. First scan is L-mode, Second scan is ELM-free
H-mode, and third scan looks like L-mode again. Probe
gets "hammered" on third scan, and plumes are saturated
on top view. Both first and third scans look like typical
L-mode plumes at the separatrix.

Next shot - going to only two scans, try and get deep
insertion on both H-modes (change timing).

Sep 15 2000 11:49:26:827AM 1000915007 BFSP Injection of C2D4

16.5 torr of C2D4 in FSP plenum

FSP firing at 0.90, 1.10 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"deep" insertion of FSP (~ +0-2 mm)

PPPL Xybion gates (SVC): 0.85 ms, 0.90 ms
LANL Xybion gates (TVC): 1.20 ms, 1.25 ms
Viewing through CII/CIII beam-splitter

Interesting data. First scan is at L-H transition,
but plumes look somewhat L-mode-ish, with low light
signals. Very small plumes. Plumes in second scan
are also small, but more intense light (more than
would be expected from small exposure increase).
Second scan shows ELMy behaviour on scanning probe
data.

Next shot - change timing of scan to make sure to get
ELM-free H-mode, and try and get good EDA as well.

Sep 15 2000 11:48:54:997AM 1000915008 BFSP Injection of C2D4

16.4 torr of C2D4 in FSP plenum

FSP firing at 0.916666, 1.11666 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"deep" insertion of FSP (~ +0-2 mm)

PPPL Xybion gates (SVC): 0.90 ms, 0.90 ms
LANL Xybion gates (TVC): 1.20 ms, 1.20 ms
Viewing through CII/CIII beam-splitter

Good data. Strong ExB flow in plumes on first
scan, which is in ELM-free phase. During second
scan, plume dispersal is less, but still have
strong evidence of boomeranging on side view,
even though it looks like we are in an L-mode
phase here. FSP was further out in the separatrix
than desired.

Next shot - push FSP further in.

Sep 15 2000 11:48:42:640AM 1000915009 BFSP Injection of C2D4

16.3 torr of C2D4 in FSP plenum

FSP firing at 0.916666, 1.11666 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"deep" insertion of FSP (~ +0-2 mm)

PPPL Xybion gates (SVC): 0.90 ms, 0.90 ms
LANL Xybion gates (TVC): 1.20 ms, 1.20 ms
Viewing through CII/CIII beam-splitter

Good data First scan looks similar to lost
shot. Second scan is in some sort of ELMy H-mode.
Plumes in this second scan have a structure
somewhat in between ELM-free H-mode and L-mode,
in terms of plume dispersion.

Next shot - go to having only one scan (in
ELM-free H-mode) and really try and go deep,
look for E_r reversal.

Sep 15 2000 11:59:46:450AM 1000915010 BFSP Injection of C2D4

16.2 torr of C2D4 in FSP plenum

FSP firing at 0.916666 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"deep" insertion of FSP (~ +0-2 mm)

PPPL Xybion gates (SVC): 0.90 ms
LANL Xybion gates (TVC): 1.20 ms
Viewing through CII/CIII beam-splitter

Fizzle. Try again next shot.

Sep 15 2000 12:28:13:343PM 1000915011 BFSP Injection of C2D4

16.2 torr of C2D4 in FSP plenum

FSP firing at 0.916666 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"deep" insertion of FSP (~ +0-2 mm)

PPPL Xybion gates (SVC): 0.90 ms
LANL Xybion gates (TVC): 1.20 ms
Viewing through CII/CIII beam-splitter

Good data. Exposures were somewhat low for both
cameras. In both fields of view, the plumes look
like they have a slice cut out of them, in the
direction upstream of the gas injection location.
Flows look like they are reversed in side view,
but not so clear the case from the top view.
Saw some arcing on the East probe of the FSP.

Next shot - lower Bt to try and produce EDA, and
keep FSP at this location.

Sep 15 2000 12:45:19:607PM 1000915012 BFSP Injection of C2D4

16.1 torr of C2D4 in FSP plenum

FSP firing at 0.916666 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"deep" insertion of FSP (~ +0-2 mm)

PPPL Xybion gates (SVC): 0.90 ms
LANL Xybion gates (TVC): 1.20 ms
Viewing through CII/CIII beam-splitter

Interesting probe data. Caught the L-H
transitions. Plumes look like "hybrids" --
part L-mode like and part H-mode like.
Some saturation at probe head in top
view.

Next shot - move probe timing to catch
H-mode, pull probe out because of worry
about arcing.

Sep 15 2000 12:55:36:810PM 1000915013 BFSP Injection of C2D4

16.1 torr of C2D4 in FSP plenum

FSP firing at 0.95 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"deep" insertion of FSP (~ +0-2 mm)

PPPL Xybion gates (SVC): 0.90 ms
LANL Xybion gates (TVC): 1.20 ms
Viewing through CII/CIII beam-splitter

Good data. Similar to shot 11. Exposures are somewhat
low, but still have good plumes. On side view, see the
double structure again in the plume - not so clear on
the side view.

Next shot - pull probe out a bit, and increase exposures.

Sep 15 2000 01:10:40:467PM 1000915014 BFSP Injection of C2D4

16.0 torr of C2D4 in FSP plenum

FSP firing at 0.95 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"deep" insertion of FSP (~ +2-4 mm)

PPPL Xybion gates (SVC): 1.05 ms
LANL Xybion gates (TVC): 1.35 ms
Viewing through CII/CIII beam-splitter

Good data on both views. Similar to some of the
other ELM-free H-mode data, though we seemed to
be in a dithering phase. Exposures are good.

Next shot - pull probe back further, to continue
doing a position scan of the ELM-free H-mode.

Sep 15 2000 01:23:55:403PM 1000915015 BFSP Injection of C2D4

15.9 torr of C2D4 in FSP plenum

FSP firing at 0.916667 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"medium" insertion of FSP (~ +9-11 mm)

PPPL Xybion gates (SVC): 1.05 ms
LANL Xybion gates (TVC): 1.35 ms
Viewing through CII/CIII beam-splitter

Good data from both cameras. Even further out,
plumes show similar behaviour - very cross-field
spread during the ELM-free H-mode.

Next shot - pull probe even further out, and
see what happens.

Sep 15 2000 01:44:38:450PM 1000915016 BFSP Injection of C2D4

15.8 torr of C2D4 in FSP plenum

FSP firing at 0.933333 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"shallow" insertion of FSP (~ +16-18 mm)

PPPL Xybion gates (SVC): 1.00 ms
LANL Xybion gates (TVC): 1.35 ms
Viewing through CII/CIII beam-splitter

Good data, though we never got into H-mode.
Plumes still exhibit a lot of cross-field
dispersion, but this may be just reproducing
our results from last week - in the far SOL,
when things are cold, ion lifetimes are long
enough that even for small ExB flow velocities
the cross-field drift can be large. Thus,
the plumes are based more on local conditions
(n_e, T_e, local E_r) rather than global
confinement mode.

Next shot - repeat shot, with corrections to
upper triangularity to get H-mode.

Sep 15 2000 01:54:01:403PM 1000915017 BFSP Injection of C2D4

15.7 torr of C2D4 in FSP plenum

FSP firing at 0.933333 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"shallow" insertion of FSP (~ +16-18 mm)

PPPL Xybion gates (SVC): 1.00 ms
LANL Xybion gates (TVC): 1.35 ms
Viewing through CII/CIII beam-splitter

Again, good data. Got an ELM-free H-mode at FSP
injection time. Exposures were slightly low. Data
exhibits significant cross-field spreading.

Next shot - push probe back in to separatrix.

Sep 15 2000 02:13:34:997PM 1000915018 BFSP Injection of C2D4

15.6 torr of C2D4 in FSP plenum

FSP firing at 0.933333 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"deep" insertion of FSP (~ +0-2 mm)

PPPL Xybion gates (SVC): 1.10 ms
LANL Xybion gates (TVC): 1.50 ms
Viewing through CII/CIII beam-splitter

Good probe data. Looks like we were in an EDA-type
phase. Plumes are different relative to ELM-free
cases at this location - less cross-field spreading.
See coherent mode on FSP.

Next shot - try and get an ELM-free H-mode.

Sep 15 2000 02:32:46:170PM 1000915019 BFSP Injection of C2D4

15.6 torr of C2D4 in FSP plenum

FSP firing at 0.933333 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"deep" insertion of FSP (~ +0-2 mm)

PPPL Xybion gates (SVC): 1.10 ms
LANL Xybion gates (TVC): 1.50 ms
Viewing through CII/CIII beam-splitter

Good data, and a good discharge. Plasma went
from ELM-free into EDA, and FSP injection occurs
during ELM-free portion. However, plumes look
more similar to previous shot (018) than shots
earlier in the day (006,011). Will have to correlate
with local conditions.

Next shot - probe into EDA portion of discharge.

Sep 15 2000 02:45:25:450PM 1000915020 BFSP Injection of C2D4

15.5 torr of C2D4 in FSP plenum

FSP firing at 0.933333, 1.2 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"deep" insertion of FSP (~ +0-2 mm)

PPPL Xybion gates (SVC): 1.10 ms, 1.10 ms
LANL Xybion gates (TVC): 1.50 ms, 1.50 ms
Viewing through CII/CIII beam-splitter

Interesting data. Got a good ELM-free scan
the first plume, and an EDA phase for the
second plume. For both plumes there seems to
be this double-structure, at least as observed
on the side view. Emission near the probe is
near symmetric in this view. Top view picture
isn't as clear.

Exposures were too high during EDA phase - got
saturation in both views.

Next shot - keep things here, adjust exposures.

Sep 15 2000 02:58:23:107PM 1000915021 BFSP Injection of C2D4

15.4 torr of C2D4 in FSP plenum

FSP firing at 0.933333, 1.2 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"deep" insertion of FSP (~ +0-2 mm)

PPPL Xybion gates (SVC): 1.20 ms, 0.95 ms
LANL Xybion gates (TVC): 1.60 ms, 1.10 ms
Viewing through CII/CIII beam-splitter

Good data. First scan, ELM-free case, looks
similar to earlier shots, and different from
last shot! Especially clear in side view. Will
be interesting to find what differences exist
in local conditions. Second scan was in an L-mode
type phase, and plumes reflect that.

Next shot - move FSP timing slightly to catch EDA,
and repeat.

Sep 15 2000 03:15:13:077PM 1000915022 BFSP Injection of C2D4

15.4 torr of C2D4 in FSP plenum

FSP firing at 0.933333, 1.25 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"deep" insertion of FSP (~ +0-2 mm)

PPPL Xybion gates (SVC): 1.20 ms, 0.95 ms
LANL Xybion gates (TVC): 1.60 ms, 1.10 ms
Viewing through CII/CIII beam-splitter

Very good data. See both an ELM-free and EDA
phase, and a significant difference in the
plume structure. Saturation near the probe
head for the EDA scan. EDA phase also had
some ELMs present.

Next shot - repeat, and move FSP timing to
avoid ELMs.

Sep 15 2000 03:31:33:187PM 1000915023 BFSP Injection of C2D4

15.3 torr of C2D4 in FSP plenum

FSP firing at 0.933333, 1.2 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"deep" insertion of FSP (~ +0-2 mm)

PPPL Xybion gates (SVC): 1.20 ms, 0.95 ms
LANL Xybion gates (TVC): 1.60 ms, 1.00 ms
Viewing through CII/CIII beam-splitter

Great data!! Both scans are in ELM-free. First
scan is typical ELM-free plume. On second scan,
we get in deeper - and see asymmetry in plumes
change direction! This indicates a reversal of
E_r at this location. FSP gets hammered - tons
of arcing. Brian is changing to a double-probe
mode to try and reduce energy flux to FSP.

Next shot - increased density slightly to get
EDA, keep probes going in deep to investigate
this reversal layer.

Sep 15 2000 03:39:48:547PM 1000915024 BFSP Injection of C2D4

15.3 torr of C2D4 in FSP plenum

FSP firing at 0.933333, 1.2 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"deep" insertion of FSP (~ +0-2 mm)

PPPL Xybion gates (SVC): 1.20 ms, 0.95 ms
LANL Xybion gates (TVC): 1.60 ms, 1.00 ms
Viewing through CII/CIII beam-splitter

Good data, though we didn't get into the E_r
reversal region. First scan looks like L-mode,
and second scan was EDA. Exposure for LANL
camera on second scan was low. Good FSP data -
coherent mode was clearly seen.

Next shot - try to go back to shot 023, look
for reversal and probe deep.

Sep 15 2000 03:59:48:950PM 1000915025 BFSP Injection of C2D4

15.3 torr of C2D4 in FSP plenum

FSP firing at 0.933333, 1.2 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"deep" insertion of FSP (~ +0-2 mm)

PPPL Xybion gates (SVC): 1.20 ms, 1.00 ms
LANL Xybion gates (TVC): 1.60 ms, 1.15 ms
Viewing through CII/CIII beam-splitter

Plasma disrupts before we inject (0.88 sec).
Try again next shot.

Sep 15 2000 04:10:28:013PM 1000915026 BFSP Injection of C2D4

15.3 torr of C2D4 in FSP plenum

FSP firing at 0.933333, 1.2 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"deep" insertion of FSP (~ +0-2 mm)

PPPL Xybion gates (SVC): 1.20 ms, 1.00 ms
LANL Xybion gates (TVC): 1.60 ms, 1.15 ms
Viewing through CII/CIII beam-splitter

First scan isn't too exciting - plasma looks
to be in L-mode. During the second scan we
are in ELM-free H-mode. The CIII plume from
the side view looks as though it is sheared
(double-structure), where (perhaps) one portion
of the plume is flowing one way and the other
portion the opposite way. This looks to be
happening along a "shear front". Not clear
on the top view, but exposures were low (I
was anticipating EDA).

Next shot - assume that both scans will be ELM-
free, and adjust exposures accordingly. Moving
in FSP slightly.

Sep 15 2000 04:18:40:560PM 1000915027 BFSP Injection of C2D4

Before this shot, replenished FSP NINJA system

16.5 torr of C2D4 in FSP plenum

FSP firing at 0.933333, 1.2 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"deep" insertion of FSP (~ +0-2 mm)

PPPL Xybion gates (SVC): 0.90 ms, 0.90 ms
LANL Xybion gates (TVC): 1.25 ms, 1.25 ms
Viewing through CII/CIII beam-splitter

Fizzle. Try again next shot.

Sep 15 2000 04:47:32:373PM 1000915028 BFSP Injection of C2D4

Before this shot, replenished FSP NINJA system

16.4 torr of C2D4 in FSP plenum

FSP firing at 0.933333, 1.2 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"deep" insertion of FSP (~ +0-2 mm)

PPPL Xybion gates (SVC): 0.95 ms, 0.95 ms
LANL Xybion gates (TVC): 1.25 ms, 1.25 ms
Viewing through CII/CIII beam-splitter

First scan is in L-mode, second in ELM-free
H-mode. H-mode scan has some characteristics
of shear-layer behaviour in the plumes, and
definitely in the FSP data. However, the probe
is peaking early, and so our exposure may be
occuring just slightly after the peak insertion,
i.e. where all the action is! Try and just this
in PUT_GATE_SETPTS, and see what happens.

Sep 15 2000 05:18:27:590PM 1000915029 BFSP Injection of C2D4

Before this shot, replenished FSP NINJA system

16.3 torr of C2D4 in FSP plenum

FSP firing at 1.0, 1.25 seconds
NINJA timing: trigger: -1.0 sec, duration: 1.25 sec
"deep" insertion of FSP (~ +0-2 mm)

PPPL Xybion gates (SVC): 0.95 ms, 0.95 ms
LANL Xybion gates (TVC): 1.25 ms, 1.25 ms
Viewing through CII/CIII beam-splitter

Only got one scan - plasma disrupts at 1.16 ms.
First scan was in ELM-free H-mode. Plumes look
similar to previous shot.

End of run.

Physics Operator Comments

Sep 15 2000 09:06:52:107AM 1000915001 Joseph Snipes Engineering setup for Friday, 15 September 2000:

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

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

Power system setup as on 1000829018

Gas setup - fill B-top with 6 psi of D2 Hybrid enabled
fill B-side lower with 1 psi of Ar Hybrid enabled
fill B-side upper with 35 psi of He Hybrid DISABLED (Yes, HELIUM)
(available for between-shot ECDC)
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

Sep 15 2000 09:08:16:217AM 1000915001 Joseph Snipes Shot 1: Copied shot 1000829018 despite the EFIT changes. So, we will probably
need to change the gaps to get what we want. Good shot.

Sep 15 2000 09:11:32:763AM 1000915001 Joseph Snipes We only got two hours of ECDC before the run because of a mixup. There was
also a problem with the hybrid this morning because the A matrix did not
respond to the coldstart. However, thanks to an e-mail from Steve Wolfe, a ccl
remcam resolved the problem. Apparently, SPANNA had been rebooted and did not
have the correct definitions prior to the ccl remcam.

Sep 15 2000 10:57:54:030AM 1000915001 Joseph Snipes Shot 1: John Rice and Chris Boswell noted that shot 1 had a clear ITB with
peaked density, though the visible bremmstrahlung profile was not
available for that shot.

Sep 15 2000 11:27:33:233AM 1000915001 Joseph Snipes Shot 8: Ramped Bt up faster and removed the flat in Bt around 1.2 s to try to
get out of ELM-free H-mode and into EDA H-mode faster to avoid impurity
buildup that leads to the L-H transition at about 1.0 s. Good shot.

Sep 15 2000 09:35:32:590AM 1000915002 Joseph Snipes Shot 2: Put in an additional ramp in ZXL by 15 mm from 0.8 to 1.4 s, then held
constant to 1.5 s to give the FSP a constant target. Good shot. FSP
target still not right. Brian wants to double the ramp rate of ZXL for
the next shot.

Sep 15 2000 09:56:43:450AM 1000915003 Joseph Snipes Shot 3: Increased ramp rate to ramp another 15 mm from 0.8 to 1.4 s in ZXL and
then held constant until 1.5 s. Good shot. Disrupted at 1.5 s
apparently because the ZXL ramp was too far.

Sep 15 2000 10:12:49:733AM 1000915004 Joseph Snipes Shot 4: Reduced ZXL ramp by 7 mm. Increased RCUR by 2 mm to reduce the outer
gap as well. Reduced nl04 from 6.5 to 6.0 x 10^19 m^-2. Fizzle!

Sep 15 2000 10:28:02:263AM 1000915005 Joseph Snipes Shot 5: Sparker did not have as high a current as on shot 4. Try again with
2 ms less pre-puff. Good shot. Disrupted again at 1.5 s. FSP target
still not quite flat.

Sep 15 2000 10:40:27:467AM 1000915006 Joseph Snipes Shot 6: Try flattening out the FSP target with a triangle in the ZXL program
at about 1.1 s. Then, reduce the ramp further out past 1.2 sec to try
to avoid pushing things too hard and causing a disruption. Changed Br0
from 0.5 mT to 1 mT to try to avoid another fizzle, though the
disruption may cause a fizzle regardless. Good shot. FSP target looks
pretty good. Disruption has gone away.

Sep 15 2000 10:54:09:590AM 1000915007 Joseph Snipes Shot 7: Change Br0 from 1 mT to 1.5 mT to try to preempt a possible fizzle.
Good shot.

Sep 15 2000 11:51:06:700AM 1000915009 Joseph Snipes Shot 9: Raised nl04 to 6.5 x 10^19 m^-3 to try to get a longer EDA H-mode.
Good shot. DNB gate valve opened though the beam did not fire. The
prefill was effected changing from 0.054 to 0.065 mTorr between shots 8
and 9.

Sep 15 2000 12:02:22:623PM 1000915010 Joseph Snipes Shot 10: Try between shot ECDC before this shot to see if we can improve the
quality of the H-mode. Also, disabling the Ar puff to see if it
is increasing the radiation. Returning to 6.0 x 10^19 m^-2. Fizzle!
I suspect the gas pressure did not get low enough to get breakdown
after the ECDC was turned off. Try again without ECDC before the shot.

Sep 15 2000 12:25:34:310PM 1000915011 Joseph Snipes Shot 11: One more time without ECDC before this shot. Good shot. Still did
not get the long EDA phase we wanted.

Sep 15 2000 12:39:32:560PM 1000915012 Joseph Snipes Shot 12: Try cutting off the return Bt ramp up at 1.0 s to see if we can keep
the EDA longer by keeping the H-mode threshold lower for longer to
avoid the Type III ELMy regime. Re-enabled the Ar puff. Good shot.
Still did not get a long EDA H-mode though.

Sep 15 2000 12:54:55:030PM 1000915013 Joseph Snipes Shot 13: Try cutting off the TF 0.1 s earlier because of delays in the change
in the TF relative to the programming. Good shot. ELM-free phase
integrates up the impurities, then collapses into L-mode, then returns
into a long EDA phase.

Sep 15 2000 01:13:41:827PM 1000915014 Joseph Snipes Shot 14: Try increasing nl04 to 6.5 x 10^19 m^-2. Excellent shot! Long EDA
H-mode from 0.88 - 1.5 s. Brian is still not happy. Picky, picky,
picky! Nice peaked density H-mode though.

Sep 15 2000 01:26:09:390PM 1000915015 Joseph Snipes Shot 15: Try nl04 = 6.25 x 10^19 m^-2 and pull in on RXU by another 1.5 cm to
increase the upper triangularity. Good shot. ELM-free with transition
then long EDA phase.

Sep 15 2000 01:41:42:373PM 1000915016 Joseph Snipes Shot 16: Tweak nl04 up to 6.3 x 10^19 m^-2. Increase upper triangularity some
more by decreasing RXU by another 1.5 cm from 0.65 s to 1.4 s. Too
much! The upper X point touches the inner wall and keeps the plasma
in L-mode throughout the shot.

Sep 15 2000 01:51:57:483PM 1000915017 Joseph Snipes Shot 17: Bring RXU back by 1.5 cm to about what it was on shot 15 and try again.
Good shot. Brief ELM-free then L-mode then long EDA H-mode.

Sep 15 2000 02:11:12:263PM 1000915018 Joseph Snipes Shot 18: Changed RXU from -0.035 to -0.03 m to slightly lower the upper
triangularity. Good shot. Nice long EDA from 0.89 - 1.57 s.

Sep 15 2000 02:27:29:967PM 1000915019 Joseph Snipes Shot 19: Brian is still not happy. Reduce nl04 to 6.1 x 10^19 m^-2. Excellent
shot. ELM-free phase early, then suddenly becomes EDA with no L-mode
phase in between. The H-mode lasts from 0.88 - 1.53 s.

Sep 15 2000 02:39:12:700PM 1000915020 Joseph Snipes Shot 20: Repeat. Disrupted at 1.35 s. A spike on the bolometers at 1.2 s
indicates that the probe may have caused the plasma to drop out of
H-mode and perhaps led to the disruption as well.

Sep 15 2000 02:55:25:373PM 1000915021 Joseph Snipes Shot 21: Repeat. Good shot. ELM-free, then L-mode, then long EDA phase.

Sep 15 2000 03:05:59:857PM 1000915022 Joseph Snipes Shot 22: Raise nl04 to 6.2 x 10^19 m^-2. Disrupted again at 1.26 s at the probe
injection time.

Sep 15 2000 03:28:27:247PM 1000915024 Joseph Snipes Shot 23: Repeat. Good shot. Two ELM-free H-modes. We have apparently found the
same density threshold for the ELM-free/EDA boundary that Amanda found
yesterday in RF H-modes at about 0.6 x 10^20 m^-2 on nl04, which
corresponds to about 1.3 x 10^20 m^-3 on NEBAR_EFIT.

Sep 15 2000 03:36:47:860PM 1000915024 Joseph Snipes Shot 24: Increase nl04 to 6.5 x 10^19 m^-2. Good shot.

Sep 15 2000 03:48:23:920PM 1000915025 Joseph Snipes Shot 25: Decrease nl04 to 6.0 x 10^19 m^-2 to ensure ELM-free H-mode. Disruption
at 0.88 s before first probe scan. Bolometer increases dramatically
at 0.86 s, which leads to a large oscillating MHD mode, which then
locks and disrupts right afterward. The probe guys will not take
credit for this one. Perhaps it was an injection of some UFO.

Sep 15 2000 04:03:30:747PM 1000915026 Joseph Snipes Shot 26: Repeat. Disrupted at 1.46 s. Probe guys do not take credit for this
one either. Big impurity injection at 0.82 s. Finally enters H-mode
at 1.08 s, then had a large H-L transition at 1.4 s, which took a bite
out of the current and led to the disruption.

Sep 15 2000 04:18:49:170PM 1000915027 Joseph Snipes Shot 27: Repeat. Fizzle!

Sep 15 2000 04:37:06:200PM 1000915028 Joseph Snipes Shot 28: Took 2 ms off of the pre-puff to 20 ms duration. Try again.
Good shot.

Sep 15 2000 04:54:32:043PM 1000915029 Joseph Snipes Shot 29: Repeat. Disrupted at 1.1 s. There were several injections that the
probe guys do not take credit for that I think led to the final
disruption.

Sep 15 2000 04:58:23:920PM 1000915029 Joseph Snipes Summary: It was a very good run with several shots with peaked density H-modes
most notably shots 1, 6, and 19. We also independently verified the density
threshold that Amanda found yesterday for the ELM-free/EDA boundary. It is
still at 0.6 x 10^20 m^-2 for nl04 programming even at low field with Ohmic
H-mode rather than RF H-mode. The probe studies also went well. See the
session leader's summary for the plume results. The machine ran very well,
though we did have a few unexplained disruptions and some resulting fizzles.

Shot,Duration(s),Ipmax(MA) Shot,Duration(s),Ipmax
1 1.923 0.814 2 1.919 0.814
3 1.403 0.809 4 0.000 0.037
5 1.471 0.812 6 1.927 0.814
7 1.924 0.814 8 1.929 0.810
9 1.932 0.809 10 0.000 0.034
11 1.933 0.809 12 1.919 0.812
13 1.921 0.814 14 1.916 0.809
15 1.923 0.809 16 1.919 0.809
17 1.918 0.809 18 1.922 0.809
19 1.923 0.812 20 1.368 0.807
21 1.920 0.809 22 1.271 0.810
23 1.920 0.812 24 1.924 0.809
25 0.891 0.809 26 1.460 0.812
27 0.000 0.037 28 1.922 0.812
29 1.178 0.817
Finished summary for 1000915 Total of 29 shots.
29 shots. 26 plasmas. 3 fizzles. 0 duds.

Engineering Operator Comments

Shot Time Type Status Comment

1 09:06:14:873AM Plasma Ok

2 09:26:57:843AM Plasma Ok

3 09:41:58:543AM Plasma Ok

4 09:58:13:687AM Plasma Ok

5 10:13:31:593AM Plasma Ok

6 10:31:40:140AM Plasma Ok

7 10:50:37:873AM Plasma Ok

8 11:15:29:950AM Plasma Ok

9 11:35:55:547AM Plasma Ok

10 11:57:17:840AM Plasma Ok

11 12:14:30:170PM Plasma Ok

12 12:29:12:670PM Plasma Ok

13 12:43:32:717PM Plasma Ok

14 12:59:07:530PM Plasma Ok

15 01:14:54:873PM Plasma Ok

16 01:31:45:513PM Plasma Ok

17 01:45:32:937PM Plasma Ok

18 02:03:58:513PM Plasma Ok

19 02:17:55:340PM Plasma Ok

20 02:32:09:657PM Plasma Ok

21 02:47:18:390PM Plasma Ok

22 03:01:07:110PM Plasma Ok

23 03:14:45:247PM Plasma Ok

24 03:28:06:903PM Plasma Ok

25 03:41:19:060PM Plasma Ok

26 03:54:41:217PM Plasma Ok

27 04:16:47:343PM Plasma Ok

28 04:31:19:513PM Plasma Ok

29 04:45:03:200PM Plasma Ok

Session Leader Comments
Sep 15 2000 08:38:28:390AM		Run plan for 1000915: MP 276 -- Transport Experiments in the Scrape-Off Layer during Ohmic L- and H-mode using Gas-Injection Plumes Run Day 2: Ohmic H-mode At constant discharge conditions, the depth of injection will be varied to determine transport variation with cross-field coordinate (rho) during H-mode. Timing of the injection will also be varied to catch various phases in the discharge, e.g. L-mode, L-H transition, ELM-free H-mode, EDA H-mode. Set-up B-field ramp so as to obtain Ohmic H-mode plasmas similar to 1000518022, but staying at I_p = 0.8 MA. Start with NL04 = 0.8e20/m^2. Shot plan: 1-6 Setup FSP target, gas, optimal camera exposures 7-12 Vary FSP timing, inject into far SOL (> ~ +15 mm) 13-17 Vary FSP timing, inject into near SOL (< ~ +3 mm) 18-20 Vary FSP timing, inject near and past separatrix
Sep 15 2000 09:21:48:873AM	1000915001	BFSP background shot For the first shot, not firing the probe or injecting gas. Use to determine background carbon light levels, for setting exposures. Exposures taken at: 0.7, 0.9, 1.1 sec PPPL Xybion gates (SVC): 0.65 ms, 0.65 ms, 0.65 ms LANL Xybion gates (TVC): 0.85 ms, 0.85 ms, 0.85 ms Very low levels of emission on each view. Good discharge! Got H-mode around 0.9 seconds, and EDA around 1.1 seconds. Next shot - change FSP timings slightly to make sure we catch the H-mode phases, and inject.
Sep 15 2000 11:50:05:983AM	1000915002	BFSP Injection of C2D4 17.0 torr of C2D4 in FSP plenum FSP firing at 0.75, 0.95, 1.15 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): 0.85 ms, 0.85 ms, 0.85 ms Viewing through CII/CIII beam-splitter Good data. Exposures were somewhat low, especially for LANL camera. Second scan is good ELM-free H-mode, and plumes from both views are very, very diffuse in nature. Third scan is in some sort of EDA, with dithering in Dalpha. Plumes are less diffuse in this case. Next shot - increase exposures, try and flatten FSP target.
Sep 15 2000 10:14:59:030AM	1000915003	BFSP Injection of C2D4 16.9 torr of C2D4 in FSP plenum FSP firing at 0.75, 0.95, 1.15 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "shallow" insertion of FSP (~ +10-12 mm) PPPL Xybion gates (SVC): 0.75 ms, 0.80 ms, 0.75 ms LANL Xybion gates (TVC): 1.00 ms, 1.15 ms, 1.10 ms Viewing through CII/CIII beam-splitter Good data. Similar to last shot, and increasing exposures helped. Saw some saturation on CII at probe head from top view. Plumes during second scan are more spread than during third scan (it seems), but more intense as well - may have to do with slightly higher exposure. Next shot - repeat, modify exposures slighty, lower density slightly to try and make sure ELM-free phase is solidly ELM-free.
Sep 15 2000 10:15:29:013AM	1000915004	BFSP Injection of C2D4 16.9 torr of C2D4 in FSP plenum FSP firing at 0.75, 0.95, 1.15 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "shallow" insertion of FSP (~ +10-12 mm) PPPL Xybion gates (SVC): 0.85 ms, 0.85 ms, 0.85 ms LANL Xybion gates (TVC): 1.05 ms, 1.10 ms, 1.10 ms Viewing through CII/CIII beam-splitter Fizzle. Try again next shot.
Sep 15 2000 11:49:45:857AM	1000915005	BFSP Injection of C2D4 16.8 torr of C2D4 in FSP plenum FSP firing at 0.75, 0.95, 1.15 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "deep" insertion of FSP (~ +0-2 mm) PPPL Xybion gates (SVC): 0.85 ms, 0.85 ms, 0.85 ms LANL Xybion gates (TVC): 1.00 ms, 1.10 ms, 1.10 ms Viewing through CII/CIII beam-splitter Good data. First scan hits the separatrix, and this is apparent on the plumes - they look very thin from the top, and as though they "hit a wall" on the side. Next two scans are H-modes, further out. First one ELM-free, and second one EDA-ish. Again, we can see difference in plume widths, with ELM-free plumes exhibiting less cross-field spreading in the field of view. Next shot - pull FSP out some (saw arcing on first scan) and change timings slightly, to catch L-H transition. Also, change exposures slightly.
Sep 15 2000 11:49:54:607AM	1000915006	BFSP Injection of C2D4 16.6 torr of C2D4 in FSP plenum FSP firing at 0.65, 0.90, 1.15 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "deep" insertion of FSP (~ +0-2 mm) PPPL Xybion gates (SVC): 0.85 ms, 0.85 ms, 0.90 ms LANL Xybion gates (TVC): 1.00 ms, 1.10 ms, 1.15 ms Viewing through CII/CIII beam-splitter Good data. First scan is L-mode, Second scan is ELM-free H-mode, and third scan looks like L-mode again. Probe gets "hammered" on third scan, and plumes are saturated on top view. Both first and third scans look like typical L-mode plumes at the separatrix. Next shot - going to only two scans, try and get deep insertion on both H-modes (change timing).
Sep 15 2000 11:49:26:827AM	1000915007	BFSP Injection of C2D4 16.5 torr of C2D4 in FSP plenum FSP firing at 0.90, 1.10 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "deep" insertion of FSP (~ +0-2 mm) PPPL Xybion gates (SVC): 0.85 ms, 0.90 ms LANL Xybion gates (TVC): 1.20 ms, 1.25 ms Viewing through CII/CIII beam-splitter Interesting data. First scan is at L-H transition, but plumes look somewhat L-mode-ish, with low light signals. Very small plumes. Plumes in second scan are also small, but more intense light (more than would be expected from small exposure increase). Second scan shows ELMy behaviour on scanning probe data. Next shot - change timing of scan to make sure to get ELM-free H-mode, and try and get good EDA as well.
Sep 15 2000 11:48:54:997AM	1000915008	BFSP Injection of C2D4 16.4 torr of C2D4 in FSP plenum FSP firing at 0.916666, 1.11666 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "deep" insertion of FSP (~ +0-2 mm) PPPL Xybion gates (SVC): 0.90 ms, 0.90 ms LANL Xybion gates (TVC): 1.20 ms, 1.20 ms Viewing through CII/CIII beam-splitter Good data. Strong ExB flow in plumes on first scan, which is in ELM-free phase. During second scan, plume dispersal is less, but still have strong evidence of boomeranging on side view, even though it looks like we are in an L-mode phase here. FSP was further out in the separatrix than desired. Next shot - push FSP further in.
Sep 15 2000 11:48:42:640AM	1000915009	BFSP Injection of C2D4 16.3 torr of C2D4 in FSP plenum FSP firing at 0.916666, 1.11666 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "deep" insertion of FSP (~ +0-2 mm) PPPL Xybion gates (SVC): 0.90 ms, 0.90 ms LANL Xybion gates (TVC): 1.20 ms, 1.20 ms Viewing through CII/CIII beam-splitter Good data First scan looks similar to lost shot. Second scan is in some sort of ELMy H-mode. Plumes in this second scan have a structure somewhat in between ELM-free H-mode and L-mode, in terms of plume dispersion. Next shot - go to having only one scan (in ELM-free H-mode) and really try and go deep, look for E_r reversal.
Sep 15 2000 11:59:46:450AM	1000915010	BFSP Injection of C2D4 16.2 torr of C2D4 in FSP plenum FSP firing at 0.916666 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "deep" insertion of FSP (~ +0-2 mm) PPPL Xybion gates (SVC): 0.90 ms LANL Xybion gates (TVC): 1.20 ms Viewing through CII/CIII beam-splitter Fizzle. Try again next shot.
Sep 15 2000 12:28:13:343PM	1000915011	BFSP Injection of C2D4 16.2 torr of C2D4 in FSP plenum FSP firing at 0.916666 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "deep" insertion of FSP (~ +0-2 mm) PPPL Xybion gates (SVC): 0.90 ms LANL Xybion gates (TVC): 1.20 ms Viewing through CII/CIII beam-splitter Good data. Exposures were somewhat low for both cameras. In both fields of view, the plumes look like they have a slice cut out of them, in the direction upstream of the gas injection location. Flows look like they are reversed in side view, but not so clear the case from the top view. Saw some arcing on the East probe of the FSP. Next shot - lower Bt to try and produce EDA, and keep FSP at this location.
Sep 15 2000 12:45:19:607PM	1000915012	BFSP Injection of C2D4 16.1 torr of C2D4 in FSP plenum FSP firing at 0.916666 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "deep" insertion of FSP (~ +0-2 mm) PPPL Xybion gates (SVC): 0.90 ms LANL Xybion gates (TVC): 1.20 ms Viewing through CII/CIII beam-splitter Interesting probe data. Caught the L-H transitions. Plumes look like "hybrids" -- part L-mode like and part H-mode like. Some saturation at probe head in top view. Next shot - move probe timing to catch H-mode, pull probe out because of worry about arcing.
Sep 15 2000 12:55:36:810PM	1000915013	BFSP Injection of C2D4 16.1 torr of C2D4 in FSP plenum FSP firing at 0.95 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "deep" insertion of FSP (~ +0-2 mm) PPPL Xybion gates (SVC): 0.90 ms LANL Xybion gates (TVC): 1.20 ms Viewing through CII/CIII beam-splitter Good data. Similar to shot 11. Exposures are somewhat low, but still have good plumes. On side view, see the double structure again in the plume - not so clear on the side view. Next shot - pull probe out a bit, and increase exposures.
Sep 15 2000 01:10:40:467PM	1000915014	BFSP Injection of C2D4 16.0 torr of C2D4 in FSP plenum FSP firing at 0.95 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "deep" insertion of FSP (~ +2-4 mm) PPPL Xybion gates (SVC): 1.05 ms LANL Xybion gates (TVC): 1.35 ms Viewing through CII/CIII beam-splitter Good data on both views. Similar to some of the other ELM-free H-mode data, though we seemed to be in a dithering phase. Exposures are good. Next shot - pull probe back further, to continue doing a position scan of the ELM-free H-mode.
Sep 15 2000 01:23:55:403PM	1000915015	BFSP Injection of C2D4 15.9 torr of C2D4 in FSP plenum FSP firing at 0.916667 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "medium" insertion of FSP (~ +9-11 mm) PPPL Xybion gates (SVC): 1.05 ms LANL Xybion gates (TVC): 1.35 ms Viewing through CII/CIII beam-splitter Good data from both cameras. Even further out, plumes show similar behaviour - very cross-field spread during the ELM-free H-mode. Next shot - pull probe even further out, and see what happens.
Sep 15 2000 01:44:38:450PM	1000915016	BFSP Injection of C2D4 15.8 torr of C2D4 in FSP plenum FSP firing at 0.933333 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "shallow" insertion of FSP (~ +16-18 mm) PPPL Xybion gates (SVC): 1.00 ms LANL Xybion gates (TVC): 1.35 ms Viewing through CII/CIII beam-splitter Good data, though we never got into H-mode. Plumes still exhibit a lot of cross-field dispersion, but this may be just reproducing our results from last week - in the far SOL, when things are cold, ion lifetimes are long enough that even for small ExB flow velocities the cross-field drift can be large. Thus, the plumes are based more on local conditions (n_e, T_e, local E_r) rather than global confinement mode. Next shot - repeat shot, with corrections to upper triangularity to get H-mode.
Sep 15 2000 01:54:01:403PM	1000915017	BFSP Injection of C2D4 15.7 torr of C2D4 in FSP plenum FSP firing at 0.933333 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "shallow" insertion of FSP (~ +16-18 mm) PPPL Xybion gates (SVC): 1.00 ms LANL Xybion gates (TVC): 1.35 ms Viewing through CII/CIII beam-splitter Again, good data. Got an ELM-free H-mode at FSP injection time. Exposures were slightly low. Data exhibits significant cross-field spreading. Next shot - push probe back in to separatrix.
Sep 15 2000 02:13:34:997PM	1000915018	BFSP Injection of C2D4 15.6 torr of C2D4 in FSP plenum FSP firing at 0.933333 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "deep" insertion of FSP (~ +0-2 mm) PPPL Xybion gates (SVC): 1.10 ms LANL Xybion gates (TVC): 1.50 ms Viewing through CII/CIII beam-splitter Good probe data. Looks like we were in an EDA-type phase. Plumes are different relative to ELM-free cases at this location - less cross-field spreading. See coherent mode on FSP. Next shot - try and get an ELM-free H-mode.
Sep 15 2000 02:32:46:170PM	1000915019	BFSP Injection of C2D4 15.6 torr of C2D4 in FSP plenum FSP firing at 0.933333 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "deep" insertion of FSP (~ +0-2 mm) PPPL Xybion gates (SVC): 1.10 ms LANL Xybion gates (TVC): 1.50 ms Viewing through CII/CIII beam-splitter Good data, and a good discharge. Plasma went from ELM-free into EDA, and FSP injection occurs during ELM-free portion. However, plumes look more similar to previous shot (018) than shots earlier in the day (006,011). Will have to correlate with local conditions. Next shot - probe into EDA portion of discharge.
Sep 15 2000 02:45:25:450PM	1000915020	BFSP Injection of C2D4 15.5 torr of C2D4 in FSP plenum FSP firing at 0.933333, 1.2 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "deep" insertion of FSP (~ +0-2 mm) PPPL Xybion gates (SVC): 1.10 ms, 1.10 ms LANL Xybion gates (TVC): 1.50 ms, 1.50 ms Viewing through CII/CIII beam-splitter Interesting data. Got a good ELM-free scan the first plume, and an EDA phase for the second plume. For both plumes there seems to be this double-structure, at least as observed on the side view. Emission near the probe is near symmetric in this view. Top view picture isn't as clear. Exposures were too high during EDA phase - got saturation in both views. Next shot - keep things here, adjust exposures.
Sep 15 2000 02:58:23:107PM	1000915021	BFSP Injection of C2D4 15.4 torr of C2D4 in FSP plenum FSP firing at 0.933333, 1.2 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "deep" insertion of FSP (~ +0-2 mm) PPPL Xybion gates (SVC): 1.20 ms, 0.95 ms LANL Xybion gates (TVC): 1.60 ms, 1.10 ms Viewing through CII/CIII beam-splitter Good data. First scan, ELM-free case, looks similar to earlier shots, and different from last shot! Especially clear in side view. Will be interesting to find what differences exist in local conditions. Second scan was in an L-mode type phase, and plumes reflect that. Next shot - move FSP timing slightly to catch EDA, and repeat.
Sep 15 2000 03:15:13:077PM	1000915022	BFSP Injection of C2D4 15.4 torr of C2D4 in FSP plenum FSP firing at 0.933333, 1.25 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "deep" insertion of FSP (~ +0-2 mm) PPPL Xybion gates (SVC): 1.20 ms, 0.95 ms LANL Xybion gates (TVC): 1.60 ms, 1.10 ms Viewing through CII/CIII beam-splitter Very good data. See both an ELM-free and EDA phase, and a significant difference in the plume structure. Saturation near the probe head for the EDA scan. EDA phase also had some ELMs present. Next shot - repeat, and move FSP timing to avoid ELMs.
Sep 15 2000 03:31:33:187PM	1000915023	BFSP Injection of C2D4 15.3 torr of C2D4 in FSP plenum FSP firing at 0.933333, 1.2 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "deep" insertion of FSP (~ +0-2 mm) PPPL Xybion gates (SVC): 1.20 ms, 0.95 ms LANL Xybion gates (TVC): 1.60 ms, 1.00 ms Viewing through CII/CIII beam-splitter Great data!! Both scans are in ELM-free. First scan is typical ELM-free plume. On second scan, we get in deeper - and see asymmetry in plumes change direction! This indicates a reversal of E_r at this location. FSP gets hammered - tons of arcing. Brian is changing to a double-probe mode to try and reduce energy flux to FSP. Next shot - increased density slightly to get EDA, keep probes going in deep to investigate this reversal layer.
Sep 15 2000 03:39:48:547PM	1000915024	BFSP Injection of C2D4 15.3 torr of C2D4 in FSP plenum FSP firing at 0.933333, 1.2 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "deep" insertion of FSP (~ +0-2 mm) PPPL Xybion gates (SVC): 1.20 ms, 0.95 ms LANL Xybion gates (TVC): 1.60 ms, 1.00 ms Viewing through CII/CIII beam-splitter Good data, though we didn't get into the E_r reversal region. First scan looks like L-mode, and second scan was EDA. Exposure for LANL camera on second scan was low. Good FSP data - coherent mode was clearly seen. Next shot - try to go back to shot 023, look for reversal and probe deep.
Sep 15 2000 03:59:48:950PM	1000915025	BFSP Injection of C2D4 15.3 torr of C2D4 in FSP plenum FSP firing at 0.933333, 1.2 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "deep" insertion of FSP (~ +0-2 mm) PPPL Xybion gates (SVC): 1.20 ms, 1.00 ms LANL Xybion gates (TVC): 1.60 ms, 1.15 ms Viewing through CII/CIII beam-splitter Plasma disrupts before we inject (0.88 sec). Try again next shot.
Sep 15 2000 04:10:28:013PM	1000915026	BFSP Injection of C2D4 15.3 torr of C2D4 in FSP plenum FSP firing at 0.933333, 1.2 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "deep" insertion of FSP (~ +0-2 mm) PPPL Xybion gates (SVC): 1.20 ms, 1.00 ms LANL Xybion gates (TVC): 1.60 ms, 1.15 ms Viewing through CII/CIII beam-splitter First scan isn't too exciting - plasma looks to be in L-mode. During the second scan we are in ELM-free H-mode. The CIII plume from the side view looks as though it is sheared (double-structure), where (perhaps) one portion of the plume is flowing one way and the other portion the opposite way. This looks to be happening along a "shear front". Not clear on the top view, but exposures were low (I was anticipating EDA). Next shot - assume that both scans will be ELM- free, and adjust exposures accordingly. Moving in FSP slightly.
Sep 15 2000 04:18:40:560PM	1000915027	BFSP Injection of C2D4 Before this shot, replenished FSP NINJA system 16.5 torr of C2D4 in FSP plenum FSP firing at 0.933333, 1.2 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "deep" insertion of FSP (~ +0-2 mm) PPPL Xybion gates (SVC): 0.90 ms, 0.90 ms LANL Xybion gates (TVC): 1.25 ms, 1.25 ms Viewing through CII/CIII beam-splitter Fizzle. Try again next shot.
Sep 15 2000 04:47:32:373PM	1000915028	BFSP Injection of C2D4 Before this shot, replenished FSP NINJA system 16.4 torr of C2D4 in FSP plenum FSP firing at 0.933333, 1.2 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "deep" insertion of FSP (~ +0-2 mm) PPPL Xybion gates (SVC): 0.95 ms, 0.95 ms LANL Xybion gates (TVC): 1.25 ms, 1.25 ms Viewing through CII/CIII beam-splitter First scan is in L-mode, second in ELM-free H-mode. H-mode scan has some characteristics of shear-layer behaviour in the plumes, and definitely in the FSP data. However, the probe is peaking early, and so our exposure may be occuring just slightly after the peak insertion, i.e. where all the action is! Try and just this in PUT_GATE_SETPTS, and see what happens.
Sep 15 2000 05:18:27:590PM	1000915029	BFSP Injection of C2D4 Before this shot, replenished FSP NINJA system 16.3 torr of C2D4 in FSP plenum FSP firing at 1.0, 1.25 seconds NINJA timing: trigger: -1.0 sec, duration: 1.25 sec "deep" insertion of FSP (~ +0-2 mm) PPPL Xybion gates (SVC): 0.95 ms, 0.95 ms LANL Xybion gates (TVC): 1.25 ms, 1.25 ms Viewing through CII/CIII beam-splitter Only got one scan - plasma disrupts at 1.16 ms. First scan was in ELM-free H-mode. Plumes look similar to previous shot. End of run.

Physics Operator Comments
Sep 15 2000 09:06:52:107AM	1000915001	Joseph Snipes	Engineering setup for Friday, 15 September 2000: Overnight ECDC in Detuterium, stopping 1-2 hours prior to the run. Run begins at 9:00 and ends at 17:00. Power system setup as on 1000829018 Gas setup - fill B-top with 6 psi of D2 Hybrid enabled fill B-side lower with 1 psi of Ar Hybrid enabled fill B-side upper with 35 psi of He Hybrid DISABLED (Yes, HELIUM) (available for between-shot ECDC) 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
Sep 15 2000 09:08:16:217AM	1000915001	Joseph Snipes	Shot 1: Copied shot 1000829018 despite the EFIT changes. So, we will probably need to change the gaps to get what we want. Good shot.
Sep 15 2000 09:11:32:763AM	1000915001	Joseph Snipes	We only got two hours of ECDC before the run because of a mixup. There was also a problem with the hybrid this morning because the A matrix did not respond to the coldstart. However, thanks to an e-mail from Steve Wolfe, a ccl remcam resolved the problem. Apparently, SPANNA had been rebooted and did not have the correct definitions prior to the ccl remcam.
Sep 15 2000 10:57:54:030AM	1000915001	Joseph Snipes	Shot 1: John Rice and Chris Boswell noted that shot 1 had a clear ITB with peaked density, though the visible bremmstrahlung profile was not available for that shot.
Sep 15 2000 11:27:33:233AM	1000915001	Joseph Snipes	Shot 8: Ramped Bt up faster and removed the flat in Bt around 1.2 s to try to get out of ELM-free H-mode and into EDA H-mode faster to avoid impurity buildup that leads to the L-H transition at about 1.0 s. Good shot.
Sep 15 2000 09:35:32:590AM	1000915002	Joseph Snipes	Shot 2: Put in an additional ramp in ZXL by 15 mm from 0.8 to 1.4 s, then held constant to 1.5 s to give the FSP a constant target. Good shot. FSP target still not right. Brian wants to double the ramp rate of ZXL for the next shot.
Sep 15 2000 09:56:43:450AM	1000915003	Joseph Snipes	Shot 3: Increased ramp rate to ramp another 15 mm from 0.8 to 1.4 s in ZXL and then held constant until 1.5 s. Good shot. Disrupted at 1.5 s apparently because the ZXL ramp was too far.
Sep 15 2000 10:12:49:733AM	1000915004	Joseph Snipes	Shot 4: Reduced ZXL ramp by 7 mm. Increased RCUR by 2 mm to reduce the outer gap as well. Reduced nl04 from 6.5 to 6.0 x 10^19 m^-2. Fizzle!
Sep 15 2000 10:28:02:263AM	1000915005	Joseph Snipes	Shot 5: Sparker did not have as high a current as on shot 4. Try again with 2 ms less pre-puff. Good shot. Disrupted again at 1.5 s. FSP target still not quite flat.
Sep 15 2000 10:40:27:467AM	1000915006	Joseph Snipes	Shot 6: Try flattening out the FSP target with a triangle in the ZXL program at about 1.1 s. Then, reduce the ramp further out past 1.2 sec to try to avoid pushing things too hard and causing a disruption. Changed Br0 from 0.5 mT to 1 mT to try to avoid another fizzle, though the disruption may cause a fizzle regardless. Good shot. FSP target looks pretty good. Disruption has gone away.
Sep 15 2000 10:54:09:590AM	1000915007	Joseph Snipes	Shot 7: Change Br0 from 1 mT to 1.5 mT to try to preempt a possible fizzle. Good shot.
Sep 15 2000 11:51:06:700AM	1000915009	Joseph Snipes	Shot 9: Raised nl04 to 6.5 x 10^19 m^-3 to try to get a longer EDA H-mode. Good shot. DNB gate valve opened though the beam did not fire. The prefill was effected changing from 0.054 to 0.065 mTorr between shots 8 and 9.
Sep 15 2000 12:02:22:623PM	1000915010	Joseph Snipes	Shot 10: Try between shot ECDC before this shot to see if we can improve the quality of the H-mode. Also, disabling the Ar puff to see if it is increasing the radiation. Returning to 6.0 x 10^19 m^-2. Fizzle! I suspect the gas pressure did not get low enough to get breakdown after the ECDC was turned off. Try again without ECDC before the shot.
Sep 15 2000 12:25:34:310PM	1000915011	Joseph Snipes	Shot 11: One more time without ECDC before this shot. Good shot. Still did not get the long EDA phase we wanted.
Sep 15 2000 12:39:32:560PM	1000915012	Joseph Snipes	Shot 12: Try cutting off the return Bt ramp up at 1.0 s to see if we can keep the EDA longer by keeping the H-mode threshold lower for longer to avoid the Type III ELMy regime. Re-enabled the Ar puff. Good shot. Still did not get a long EDA H-mode though.
Sep 15 2000 12:54:55:030PM	1000915013	Joseph Snipes	Shot 13: Try cutting off the TF 0.1 s earlier because of delays in the change in the TF relative to the programming. Good shot. ELM-free phase integrates up the impurities, then collapses into L-mode, then returns into a long EDA phase.
Sep 15 2000 01:13:41:827PM	1000915014	Joseph Snipes	Shot 14: Try increasing nl04 to 6.5 x 10^19 m^-2. Excellent shot! Long EDA H-mode from 0.88 - 1.5 s. Brian is still not happy. Picky, picky, picky! Nice peaked density H-mode though.
Sep 15 2000 01:26:09:390PM	1000915015	Joseph Snipes	Shot 15: Try nl04 = 6.25 x 10^19 m^-2 and pull in on RXU by another 1.5 cm to increase the upper triangularity. Good shot. ELM-free with transition then long EDA phase.
Sep 15 2000 01:41:42:373PM	1000915016	Joseph Snipes	Shot 16: Tweak nl04 up to 6.3 x 10^19 m^-2. Increase upper triangularity some more by decreasing RXU by another 1.5 cm from 0.65 s to 1.4 s. Too much! The upper X point touches the inner wall and keeps the plasma in L-mode throughout the shot.
Sep 15 2000 01:51:57:483PM	1000915017	Joseph Snipes	Shot 17: Bring RXU back by 1.5 cm to about what it was on shot 15 and try again. Good shot. Brief ELM-free then L-mode then long EDA H-mode.
Sep 15 2000 02:11:12:263PM	1000915018	Joseph Snipes	Shot 18: Changed RXU from -0.035 to -0.03 m to slightly lower the upper triangularity. Good shot. Nice long EDA from 0.89 - 1.57 s.
Sep 15 2000 02:27:29:967PM	1000915019	Joseph Snipes	Shot 19: Brian is still not happy. Reduce nl04 to 6.1 x 10^19 m^-2. Excellent shot. ELM-free phase early, then suddenly becomes EDA with no L-mode phase in between. The H-mode lasts from 0.88 - 1.53 s.
Sep 15 2000 02:39:12:700PM	1000915020	Joseph Snipes	Shot 20: Repeat. Disrupted at 1.35 s. A spike on the bolometers at 1.2 s indicates that the probe may have caused the plasma to drop out of H-mode and perhaps led to the disruption as well.
Sep 15 2000 02:55:25:373PM	1000915021	Joseph Snipes	Shot 21: Repeat. Good shot. ELM-free, then L-mode, then long EDA phase.
Sep 15 2000 03:05:59:857PM	1000915022	Joseph Snipes	Shot 22: Raise nl04 to 6.2 x 10^19 m^-2. Disrupted again at 1.26 s at the probe injection time.
Sep 15 2000 03:28:27:247PM	1000915024	Joseph Snipes	Shot 23: Repeat. Good shot. Two ELM-free H-modes. We have apparently found the same density threshold for the ELM-free/EDA boundary that Amanda found yesterday in RF H-modes at about 0.6 x 10^20 m^-2 on nl04, which corresponds to about 1.3 x 10^20 m^-3 on NEBAR_EFIT.
Sep 15 2000 03:36:47:860PM	1000915024	Joseph Snipes	Shot 24: Increase nl04 to 6.5 x 10^19 m^-2. Good shot.
Sep 15 2000 03:48:23:920PM	1000915025	Joseph Snipes	Shot 25: Decrease nl04 to 6.0 x 10^19 m^-2 to ensure ELM-free H-mode. Disruption at 0.88 s before first probe scan. Bolometer increases dramatically at 0.86 s, which leads to a large oscillating MHD mode, which then locks and disrupts right afterward. The probe guys will not take credit for this one. Perhaps it was an injection of some UFO.
Sep 15 2000 04:03:30:747PM	1000915026	Joseph Snipes	Shot 26: Repeat. Disrupted at 1.46 s. Probe guys do not take credit for this one either. Big impurity injection at 0.82 s. Finally enters H-mode at 1.08 s, then had a large H-L transition at 1.4 s, which took a bite out of the current and led to the disruption.
Sep 15 2000 04:18:49:170PM	1000915027	Joseph Snipes	Shot 27: Repeat. Fizzle!
Sep 15 2000 04:37:06:200PM	1000915028	Joseph Snipes	Shot 28: Took 2 ms off of the pre-puff to 20 ms duration. Try again. Good shot.
Sep 15 2000 04:54:32:043PM	1000915029	Joseph Snipes	Shot 29: Repeat. Disrupted at 1.1 s. There were several injections that the probe guys do not take credit for that I think led to the final disruption.
Sep 15 2000 04:58:23:920PM	1000915029	Joseph Snipes	Summary: It was a very good run with several shots with peaked density H-modes most notably shots 1, 6, and 19. We also independently verified the density threshold that Amanda found yesterday for the ELM-free/EDA boundary. It is still at 0.6 x 10^20 m^-2 for nl04 programming even at low field with Ohmic H-mode rather than RF H-mode. The probe studies also went well. See the session leader's summary for the plume results. The machine ran very well, though we did have a few unexplained disruptions and some resulting fizzles. Shot,Duration(s),Ipmax(MA) Shot,Duration(s),Ipmax 1 1.923 0.814 2 1.919 0.814 3 1.403 0.809 4 0.000 0.037 5 1.471 0.812 6 1.927 0.814 7 1.924 0.814 8 1.929 0.810 9 1.932 0.809 10 0.000 0.034 11 1.933 0.809 12 1.919 0.812 13 1.921 0.814 14 1.916 0.809 15 1.923 0.809 16 1.919 0.809 17 1.918 0.809 18 1.922 0.809 19 1.923 0.812 20 1.368 0.807 21 1.920 0.809 22 1.271 0.810 23 1.920 0.812 24 1.924 0.809 25 0.891 0.809 26 1.460 0.812 27 0.000 0.037 28 1.922 0.812 29 1.178 0.817 Finished summary for 1000915 Total of 29 shots. 29 shots. 26 plasmas. 3 fizzles. 0 duds.

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	09:06:14:873AM	Plasma	Ok
2	09:26:57:843AM	Plasma	Ok
3	09:41:58:543AM	Plasma	Ok
4	09:58:13:687AM	Plasma	Ok
5	10:13:31:593AM	Plasma	Ok
6	10:31:40:140AM	Plasma	Ok
7	10:50:37:873AM	Plasma	Ok
8	11:15:29:950AM	Plasma	Ok
9	11:35:55:547AM	Plasma	Ok
10	11:57:17:840AM	Plasma	Ok
11	12:14:30:170PM	Plasma	Ok
12	12:29:12:670PM	Plasma	Ok
13	12:43:32:717PM	Plasma	Ok
14	12:59:07:530PM	Plasma	Ok
15	01:14:54:873PM	Plasma	Ok
16	01:31:45:513PM	Plasma	Ok
17	01:45:32:937PM	Plasma	Ok
18	02:03:58:513PM	Plasma	Ok
19	02:17:55:340PM	Plasma	Ok
20	02:32:09:657PM	Plasma	Ok
21	02:47:18:390PM	Plasma	Ok
22	03:01:07:110PM	Plasma	Ok
23	03:14:45:247PM	Plasma	Ok
24	03:28:06:903PM	Plasma	Ok
25	03:41:19:060PM	Plasma	Ok
26	03:54:41:217PM	Plasma	Ok
27	04:16:47:343PM	Plasma	Ok
28	04:31:19:513PM	Plasma	Ok
29	04:45:03:200PM	Plasma	Ok