Alcator C-Mod Run 1030613 Information

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Miniproposals
Miniproposal:282
Date Filed: 9/8/2000
Title:Triggering ELMs by fast current ramp-up
First Author:Dmitri Mossessian
Session Leader:Olaf Grulke (shots 1-11)
Miniproposal:332
Date Filed: 4/8/2003
Title:A new approach to the study of turbulent edge plasma fluctuations.
First Author:Olaf Grulke
Session Leader:Dmitri Mossessian (shots 12-36)

Operators
Session leader(s):Olaf Grulke,Dmitri Mossessian
Physics operator(s):Dmitri Mossessian
Engineering operator(s): Unknown

Engineering Operator Run Comment
MP#332 Turbulence (L-mode data); SL Grulke; PO Mossessian; EO Dekow/Fitz

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:33:147PM
Author: Dmitri Mossessian
un summary for the first half of 1030613 - MP282, driving ELMs with current
ramp

We had only 10 shots on 1030612, when this MP was originally scheduled,
because of some computer problems, and we continued on the 13th where we
stopped on 12th. We had 10 shots scheduled for today, but this turned out
to be enough to prove that ELMs can be driven on C-Mod by a current ramp. On
the other hand, the results that we obtained can only be considered as an
indication of that possibility, rather than a definite prove that the
peeling/ballooning theory works here. In short, we did see high frequency
fluctuations in D-alpha signal that appear when plasma current is ramped up
and do not show up in an identical shot without the current ramp. PCI
diagnostic showed that these fluctuations interrupt the QC mode at the edge.
We have yet to look at the magnetics to see if we can identify some ELMs
precursors there. The fluctuations occur, as it was expected, at high pedestal
temperature, low density and low triangularity. We did not have a chance to do
a careful shape scan to see if weak shaping is better for ELMs, as the theory
suggests. The pedestal temperatures that we were able to obtain were quite low
for given RF power (4 - 5 MW) and target density (6-5e20) - generally less
than 600 eV.
The preliminary conclusion therefore would be that ELMs can be triggered by
fast current ramp but generally require pedestal temperature higher,
and collisionality lower than was achieved. The experiment should be repeated
when better RF coupling and higher plasma temperatures will be achievable to
carry out the pedestal temperature scan between 500 and 1000 eV and observe
changes in ELMs behavior.


Details:


----------------------------------------------------------------------------
1030613001 mossessian PHYSICS_OPERATOR Jun 13 2003
9:06:50:760AM
. . . . . . . . . . . . . . . . . . . .
No power shot - Josh is working on some software

Next shot - try plasma
----------------------------------------------------------------------------
1030613002 mossessian PHYSICS_OPERATOR Jun 13 2003
9:36:23:310AM
. . . . . . . . . . . . . . . . . . . .
Good H-mode. Only 1.3 MW of RF. No current ramp effect.

Next shot - try full RF power. Drop upper triangularity (RXU out 1 cm) and
elongation (ZXU up 1 cm)
----------------------------------------------------------------------------
1030613004 mossessian PHYSICS_OPERATOR Jun 13 2003
9:57:35:070AM
. . . . . . . . . . . . . . . . . . . .
RF not steady. Plasma disrupted after current ramp due to large injection
(caused by RF ?)

Next shot - move beginning of RF to 0.9 s to get hotter H-mode into current
ramp.
Reduce upper delta some more (RXU + 1cm). Add 2 mm ramp to RCUR at .95 s to
try to compensate for current
ramp effect
----------------------------------------------------------------------------
1030613005 mossessian PHYSICS_OPERATOR Jun 13 2003
10:09:45:630AM
. . . . . . . . . . . . . . . . . . . .
RF trips a lot.

Next shot - plasma seems to be stable enough and we will try to increase
current ramp rate somewhat. RXU + 1cm
Add 3 mm to RCUR to increase right gap a little
----------------------------------------------------------------------------
1030613006 mossessian PHYSICS_OPERATOR Jun 13 2003
10:18:49:496AM
. . . . . . . . . . . . . . . . . . . .
Good shot. Steady RF at 3.5 MW, Te_ped ~ 500 eV, good current rise. definitely
no ELMs driven


Next shot - lower target density to 5e19
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1030613007 mossessian PHYSICS_OPERATOR Jun 13 2003
10:29:59:400AM
. . . . . . . . . . . . . . . . . . . .
Good shot. Target 6e19. Te_ped ~ 500 eV. Burst of ELMs between 1 and 1.04 s.

Next shot - turn current ramp OFF
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1030613008 mossessian PHYSICS_OPERATOR Jun 13 2003
10:51:42:830AM
. . . . . . . . . . . . . . . . . . . .
Good shot. Repeats shot 7 but grassy ELMs disappear.
Try to increase the effect on next couple of shots - increase RF power and
drop upper delta more.

Next shot - RXU + 1cm, current ramp on. Increase current ramp rate - now
ramping to .85 MA
----------------------------------------------------------------------------
1030613009 mossessian PHYSICS_OPERATOR Jun 13 2003
10:58:38:853AM
. . . . . . . . . . . . . . . . . . . .
Decreasing upper delta seems to make things worse - almost no effect of
current ramp seen on D-alpha.

Next shot - RXU -2 cm
----------------------------------------------------------------------------
1030613010 mossessian PHYSICS_OPERATOR Jun 13 2003
11:16:13:750AM
. . . . . . . . . . . . . . . . . . . .
Lost density feedback in the middle of the shot. Got max gas puff right from
the beginning of H-mode.
After H-L transition density was rising and plasma disrupted at 1.46 s

Next shot - repeat with higher current ramp rate. PG4 from 23 to 21 ms
----------------------------------------------------------------------------
1030613011 mossessian PHYSICS_OPERATOR Jun 13 2003
11:26:11:696AM
. . . . . . . . . . . . . . . . . . . .
Better than 10 although still disrupted. ELMs seem to be there during Ip ramp.




Entered: Jul 7 2004 03:49:33:180PM
Author: Olaf Grulke
Run summary for the second half of 1030613
From:
Olaf Grulke
Date:
Tue, 17 Jun 2003 13:35:11 -0400

This run is to used to carry out the non-piggyback ohmic part of MP 332.
The idea was to make a simultaneous spatiotemporal measurement of
plasma density and plasma potential fluctuations. This is done
by establishing a magnetic mapping between the observation
region of the GPI system and the F-probe. This mapping occurs
when Bt=5.4 T and I_p=610 kA. We measured cross-correlation
between I-sat and V-floating signals of the F-port probe and
the light fluctuations on the radial array of GPI views over a
L-mode density scan. We also took movies of GPI viewing
region using the PSI camera. We also tried to look during EDA H-mode,
but were unsuccessful in making an EDA H-mode.

Plan:
1) setup a shot with the correct magnetic mapping from
the FSP to the GPI viewing region (Bt=5.4 T, Ip=600kA with NL_04=0.8e20
2) decrease the density on subsequent shots in increments of 0.2e20, to
NL_04=0.4e20
3) then take shots with density of 1.1e20, and then 1.3e20
4) proceed to making EDA H-modes with ~2MW of RF at a
density chosen based on above density scan

We desire the following diagnostics:
FSP
ASP
GPI cameras
GPI fast diode array
NINJA gas-puffing from A-B limiter
edge TS
Dalsa for edge density

RESULTS: 1) We successfully completed the L-mode density scan. The somewhat
surprising result is that the probe-diode correlation DECREASED to small
values at densities NL_04<0.7e20 indicating that collisionality is not the
major influence on the parallel correlation of fluctuations.

2) We found that at densities NL_04<0.7e20 the plasma created by recycling off
of the probe body in the far-SOL maps (with some cross-field
spreading)along the local flux tube. The observational evidence for this
was the appearance of plasma in the far-SOL regions viewed by the diodes
when the probe is inserted, but only when the probe maps magnetically to
the diode-viewing region.

3) The probe-diode correlation is 30-45% at densities (NL_04) between 1 and
1.3e20.In this range the cross-correlation between diode and floating
potential has a "dipole" structure, positive for negative lag times and
negative for positive lag times. This result is consistent findings at other
fusion devices as stellarators and tokamaks and maybe a result of the
conventional picture of vortices convecting plasma across the plasma pressure
gradient and thereby causing plasma density fluctuations.


The shot by shot summary follows:



Begin MP 332 with shot 1030613012

012 - I_p=600 kA and target NL_04=0.7e20.
Use this shot to test the plamas target for probe insertion.
Timings of fluctuation diagnostics are for looking at 0.8 sec, i.e.
PSI @ 0.8 sec
diodes starting at 0.75s, thru 0.878 s
NINJA puff trigger at 0.6 s open for 0.15 s
Good shot.


013 - request: I_p=600 kA and target NL_04=0.7e20.
actual NL_04=0.8e20
1st F-probe insertion at 0.8 s.

014 - repeat
actual NL_04=0.8e20
good plasma

015 - drop density
request: NL_04=0.5e20
actual NL_04=0.65e20 @ 0.8 s
good plasma

016 - request: NL_04=0.5e20
actual NL_04=0.65e20 @ 0.8 s
good plasma

017- go to lower density
request: NL_04=0.4e20
actual NL_04=0.60e20 @ 0.8 s
good plasma
See clear evidence of probe insertion on the diode signals.
The probe-diode correlations are not good - 20% at maximum.
The far-SOL viewing channels see a strong increase
in emission, while the channels viewing inside the
separatrix see a decrease in emission.
Possible explanation is that the probe creates local
plasma via recycling. That plasma maps to the diode views, but spreads
perppendiclual to the field as well. The reson for the decrease in
emission for the inside channels may be shadowing by this
increase in far-SOL plasma.

018 - repeat 017
disrupted

019 - repeat 017
request: NL_04=0.4e20
actual NL_04=0.56e20 @ 0.8 s
good plasma
Poor probe-diode correlation.
Again see clear evidence of probe-created plasma in the far-SOL
and shadowing for the views inside the separatrix.

020 - drop density
request: NL_04=0.3e20
actual NL_04=0.49e20 @ 0.8 s
good plasma
Poor probe-diode correlation.
Again see clear evidence of probe-created plasma in the far-SOL
and shadowing for the views inside the separatrix.
When the PSI triggers at 0.8 s, it sees the plasma in the
far-SOL, i.e. the blobs are close to the nozzle

021 - repeat 020
request: NL_04=0.3e20
actual NL_04=0.48e20 @ 0.8 s
good plasma
Poor probe-diode correlation.
Again see clear evidence of probe-created plasma in the far-SOL
and shadowing for the views inside the separatrix.
Moved PSI trigger to 0.785,i.e. before the probe-created
plasma is in the diode f-of-v. The emission (with blobs) move
inward, closer to the separatrix.

022 - repeat 021, but with higher I_p (800 kA). This will destroy the mapping
between probe and diodes. request: NL_04=0.5e20 actual NL_04=0.68e20 @ 0.8 s
good plasma No probe-diode correlation, as expected. No probe-created plasma
seen be diodes, confirming the hypotheses that the probe creates the far-SOL
plasma seen on the diodes and that that plasma is local, mapping with the flux
tube. PSI trigger still 0.785.

023 - no power shot

024 - request higher denity, back to I_p=600 kA for which probe diode
mapping exists.
MARFE - disrupts

025 - try again, this time ramping the density.
request: NL_04=1.0e20
actual NL_04=1.1e20 @ 0.8 s
good plasma
regained "good" (0.3-0.4) probe-diode correlation.
PSI trigger at 0.785.

026 - repeat 025
request: NL_04=1.0e20
actual NL_04=1.1e20 @ 0.8 s
good plasma
regained "good" (0.3-0.4) probe-diode correlation.
PSI trigger at 0.785.

027 - go to higher density
request: NL_04=1.1e20
actual NL_04=1.18e20 @ 0.8 s
good plasma
regained "good" (0.3-0.4) probe-diode correlation.
See classic "dipole" effect on the
diode-probe correlation function.
PSI trigger at 0.785.

028 - repeat 027
request: NL_04=1.1e20
actual NL_04=1.18e20 @ 0.8 s
good plasma
regained "good" (0.3-0.4) probe-diode correlation.
See classic "dipole" signature on the
diode-probe correlation function.
PSI trigger at 0.795, the time of maximum correlation.

029 - go to slightly higher density
request: NL_04=1.2e20
actual NL_04=1.25e20 @ 0.8 s
good plasma
Still "good" (0.3-0.4) probe-diode correlation.
See classic "dipole" signature on the
diode-probe correlation function.
PSI trigger at 0.795, the time of maximum correlation.

030 - fizzle

031 - repeat of 029
request: NL_04=1.2e20
actual NL_04=1.28e20 @ 0.8 s
good plasma
Still "good" (0.3-0.4) probe-diode correlation.
See classic "dipole" signature on the
diode-probe correlation function.
PSI trigger at 0.795, the time of maximum correlation.

032 - fizzle

033 - fill in density point around 0.95e20
request: NL_04=0.85e20
actual NL_04=1.0e20 @ 0.8 s
good plasma
Still "good" (0.3-0.4) probe-diode correlation.

034 - go to EDA H-mode part of the MP
request: NL_04=0.85e20, RF power stepped from 1.5 to 2.0 MW at 1. sec
actual: NL_04=1.1e20, RF tripped, no H-modes
timings are still all set around 0.8 s


035 - try to repeat with RF staying on
request: NL_04=0.85e20, RF power stepped from 1.5 to 2.0 MW at 1. sec
actual: NL_04=1.1e20, RF tripping, no H-modes
timings are still all set around 0.8 s

036 fizzle



Physics Operator Summaries
Entered: Jul 7 2004 04:37:18:363PM
Author: Dmitri Mossessian

Physop summary for 1030613

PO Mossessian

SL Mossessian (MP282), Gurke (MP332)

Summary:

Good run. We started by continuing MP282 that we did not finish yesterday because of
very long delay due to computer problems. After 10 shots we switched to MP332.
Plasma ran well. Startup varies. Sometimes current rise is very ugly and there is a
strong hesitation, but it survived most of the times - at least untill I tried to fix it.
My attempts to fix the current rise by changing gas puff led to several fizzles at the end
of the run. In general, if PO does not touch the startup current rise is very smooth
in half of the shots.
Various changes were done to PCS shot programming in segment 2 - see details below for details.

Total:

36 shots
2 tests
3 fizzles


Details:


----------------------------------------------------------------------------
1030613001 mossessian PHYSICS_OPERATOR Jun 13 2003 9:06:50:760AM
. . . . . . . . . . . . . . . . . . . .
No power shot - Josh is working on some software

Next shot - try plasma
----------------------------------------------------------------------------
1030613002 mossessian PHYSICS_OPERATOR Jun 13 2003 9:36:23:310AM
. . . . . . . . . . . . . . . . . . . .
Good H-mode. Only 1.3 MW of RF. No current ramp effect.

Next shot - try full RF power. Drop upper triangularity (RXU out 1 cm) and elongation (ZXU up 1 cm)
----------------------------------------------------------------------------
1030613004 mossessian PHYSICS_OPERATOR Jun 13 2003 9:57:35:070AM
. . . . . . . . . . . . . . . . . . . .
RF not steady. Plasma disrupted after current ramp due to large injection (caused by RF ?)

Next shot - move beginning of RF to 0.9 s to get hotter H-mode into current ramp.
Reduce upper delta some more (RXU + 1cm). Add 2 mm ramp to RCUR at .95 s to try to compensate for current
ramp effect
----------------------------------------------------------------------------
1030613005 mossessian PHYSICS_OPERATOR Jun 13 2003 10:09:45:630AM
. . . . . . . . . . . . . . . . . . . .
RF trips a lot.

Next shot - plasma seems to be stable enough and we will try to increase current ramp rate somewhat. RXU + 1cm
Add 3 mm to RCUR to increase right gap a little
----------------------------------------------------------------------------
1030613006 mossessian PHYSICS_OPERATOR Jun 13 2003 10:18:49:496AM
. . . . . . . . . . . . . . . . . . . .
Good shot. Steady RF at 3.5 MW, Te_ped ~ 500 eV, good current rise. definitely no ELMs driven


Next shot - lower target density to 5e19
----------------------------------------------------------------------------
1030613007 mossessian PHYSICS_OPERATOR Jun 13 2003 10:29:59:400AM
. . . . . . . . . . . . . . . . . . . .
Good shot. Target 6e19. Te_ped ~ 500 eV. Burst of ELMs between 1 and 1.04 s.

Next shot - turn current ramp OFF
----------------------------------------------------------------------------
1030613008 mossessian PHYSICS_OPERATOR Jun 13 2003 10:51:42:830AM
. . . . . . . . . . . . . . . . . . . .
Good shot. Repeats shot 7 but grassy ELMs disappear.
Try to increase the effect on next couple of shots - increase RF power and drop upper delta more.

Next shot - RXU + 1cm, current ramp on. Increase current ramp rate - now ramping to .85 MA
----------------------------------------------------------------------------
1030613009 mossessian PHYSICS_OPERATOR Jun 13 2003 10:58:38:853AM
. . . . . . . . . . . . . . . . . . . .
Decreasing upper delta seems to make things worse - almost no effect of current ramp seen on D-alpha.

Next shot - RXU -2 cm
----------------------------------------------------------------------------
1030613010 mossessian PHYSICS_OPERATOR Jun 13 2003 11:16:13:750AM
. . . . . . . . . . . . . . . . . . . .
Lost density feedback in the middle of the shot. Got max gas puff right from the beginning of H-mode.
After H-L transition density was rising and plasma disrupted at 1.46 s

Next shot - repeat with higher current ramp rate. PG4 from 23 to 21 ms
----------------------------------------------------------------------------
1030613011 mossessian PHYSICS_OPERATOR Jun 13 2003 11:26:11:696AM
. . . . . . . . . . . . . . . . . . . .
Better than 10 although still disrupted. ELMs seem to be there during Ip ramp.

This ends MP 282

Next shot - go to MP 332. Load segment 2 from 1030604010.
----------------------------------------------------------------------------
1030613012 mossessian PHYSICS_OPERATOR Jun 13 2003 11:44:37:780AM
. . . . . . . . . . . . . . . . . . . .
Plasma. nl=0.8e20, asked for 0.7e20.

Next shot - CLEARIN down 5 mm
----------------------------------------------------------------------------
1030613013 mossessian PHYSICS_OPERATOR Jun 13 2003 11:59:29:486AM
. . . . . . . . . . . . . . . . . . . .
Plasma. After F-probe plunge at 0.8 s edge cools down to 0 eV at 0.85 for 150 ms.

Next shot - add 10 ms to Ar (PG1). CLEARIN down 3 mm
----------------------------------------------------------------------------
1030613014 mossessian PHYSICS_OPERATOR Jun 13 2003 12:06:37:540PM
. . . . . . . . . . . . . . . . . . . .
Plasma

Next shot - nl -> 5e19
----------------------------------------------------------------------------
1030613016 mossessian PHYSICS_OPERATOR Jun 13 2003 12:32:33:696PM
. . . . . . . . . . . . . . . . . . . .
Plasma

Next shot - nl -> 4e19
----------------------------------------------------------------------------
1030613015 mossessian PHYSICS_OPERATOR Jun 13 2003 12:32:43:570PM
. . . . . . . . . . . . . . . . . . . .
Plasma

Next shot - no changes
----------------------------------------------------------------------------
1030613017 mossessian PHYSICS_OPERATOR Jun 13 2003 12:48:20:556PM
. . . . . . . . . . . . . . . . . . . .
Plasma

Next shot - CLEARIN + 2mm
----------------------------------------------------------------------------
1030613018 mossessian PHYSICS_OPERATOR Jun 13 2003 1:00:42:416PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Disrupted at .3 s - lost TCI feedback

Next shot - no changes
----------------------------------------------------------------------------
1030613019 mossessian PHYSICS_OPERATOR Jun 13 2003 1:12:55:163PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

Next shot - nl-> 3e19
----------------------------------------------------------------------------
1030613021 mossessian PHYSICS_OPERATOR Jun 13 2003 1:45:10:110PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

Next shot - nl -> 5e19 Ip -> 0.8 MA
----------------------------------------------------------------------------
1030613022 mossessian PHYSICS_OPERATOR Jun 13 2003 1:59:28:686PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

Next shot - nl -> 1e20 Ip -> 0.6 MA
----------------------------------------------------------------------------
1030613023 mossessian PHYSICS_OPERATOR Jun 13 2003 2:05:20:553PM
. . . . . . . . . . . . . . . . . . . .
No power shot. EF troubles
----------------------------------------------------------------------------
1030613024 mossessian PHYSICS_OPERATOR Jun 13 2003 2:29:02:190PM
. . . . . . . . . . . . . . . . . . . .
Plasma killed by giant MARFE that starts around 0.5 s.

Next shot - slow down density rise to bring it to 1e20 by 0.8 s
----------------------------------------------------------------------------
1030613025 mossessian PHYSICS_OPERATOR Jun 13 2003 2:39:49:453PM
. . . . . . . . . . . . . . . . . . . .
Good shot

Next shot - no change
----------------------------------------------------------------------------
1030613026 mossessian PHYSICS_OPERATOR Jun 13 2003 3:08:12:860PM
. . . . . . . . . . . . . . . . . . . .
Good shot

Next shot - nl -> 1.1e20
----------------------------------------------------------------------------
1030613027 mossessian PHYSICS_OPERATOR Jun 13 2003 3:08:22:220PM
. . . . . . . . . . . . . . . . . . . .
Good shot

Next shot - no change
----------------------------------------------------------------------------
1030613028 mossessian PHYSICS_OPERATOR Jun 13 2003 3:13:22:473PM
. . . . . . . . . . . . . . . . . . . .
Good shot

Next shot - nl -> 1.2e20
----------------------------------------------------------------------------
1030613029 mossessian PHYSICS_OPERATOR Jun 13 2003 3:28:32:740PM
. . . . . . . . . . . . . . . . . . . .
Good shot

Next shot - no change
----------------------------------------------------------------------------
1030613030 mossessian PHYSICS_OPERATOR Jun 13 2003 3:48:51:876PM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Current rise too fast

Next shot - add 3 ms to PG4 21 -> 24 ms
----------------------------------------------------------------------------
1030613031 mossessian PHYSICS_OPERATOR Jun 13 2003 3:55:14:146PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

Next shot - nl-> 0.85e20, add 2 ms to PG4
----------------------------------------------------------------------------
1030613032 mossessian PHYSICS_OPERATOR Jun 13 2003 4:11:50:090PM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Too much gas

Next shot - reduce PG4 (-3 ms)
----------------------------------------------------------------------------
1030613033 mossessian PHYSICS_OPERATOR Jun 13 2003 4:21:52:100PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Very bad startup

Next shot - nl -> 1e20
----------------------------------------------------------------------------
1030613034 mossessian PHYSICS_OPERATOR Jun 13 2003 4:32:01:363PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Startup is good. No H-mode - poor RF matching

Next shot -repeat
----------------------------------------------------------------------------
1030613036 mossessian PHYSICS_OPERATOR Jun 13 2003 4:59:09:970PM
. . . . . . . . . . . . . . . . . . . .
Fizzle
----------------------------------------------------------------------------
1030613xxx mossessian PHYSICS_OPERATOR Jun 13 2003 8:58:17:296AM
. . . . . . . . . . . . . . . . . . . .
Comntinue yesterday's runa (MP282). For details see SESSION LEADER logbook entries for yesterday.

Load 1030612006. RF from .7 s, 4 MW - attempt to repeat shots 6 taht had large ELMs driven by current


Session Leader Comments
Jun 13 2003 02:31:08:757PMJim TerryThis run is to used to carry out the non-piggyback part of MP 332. The idea is to make a
simultaneous spatiotemporal measurement of plasma density and plasma potential
fluctuations. This is done by estaablishing a magnetic mapping between the observation
region of the GPI system and the F-probe. This mapping occurs when Bt=5.4 T and I_p=610 kA.
We will be measuring the magnitude and delay of the
cross-correlation between I-sat and V-floating signals
on the probe and the light fluctuations on the radial array of GPI views
under a variety of plasma conditions:

Ohmic L-mode density scan
RF-heated EDA H-mode
RF-heated ELM-free H-mode


Plan:
1) setup by loading shot 1030604016, with NL_04=1e20
2) decrease the density on subsequent shots in increments of 0.2e20, to NL_04=0.4e20
3) then take two shots with density of 1.2e20, and then 1.4e20
4) proceed to making EDA H-modes with ~3MW of RF at a
density chosen based on above density scan
5) if time allows, reduce the density to make ELM-free H-modes

In each of these conditions we will be measuring the
cross-correlation between I-sat and V-floating signals
on the probe and the light fluctuations on the radial
array of GPI views, as well as taking movies of the GPI vieewing
region with the PSI camera.

We desire the following diagnostics:

FSP
ASP
GPI cameras
GPI fast diode array
NINJA gas-puffing from A-B limiter
edge TS
Dalsa for edge density profiles

This part of the run began on shot 103613012
Jun 13 2003 02:36:51:433PM1030613012Jim TerryBegin MP 332 with I_p=600 kA and target NL_04=0.7e20.
Use this shot to test the plamas target for probe insertion.
Timings of fluctuation diagnostics are for looking at 0.8 sec, i.e.
PSI @ 0.8 sec
diodes starting at 0.75s, thru 0.878 s
NINJA puff trigger at 0.6 s open for 0.15 s
Good shot.
Jun 13 2003 02:41:45:923PM1030613013Jim Terryrequest: I_p=600 kA and target NL_04=0.7e20.
actual NL_04=0.8e20
1st F-probe insertion at 0.8 s.
Jun 13 2003 02:43:13:487PM1030613014Jim Terryrepeat
actual NL_04=0.8e20
good plasma
Jun 13 2003 02:44:38:770PM1030613015Jim Terrydrop density
request: NL_04=0.5e20
actual NL_04=0.65e20 @ 0.8 s
good plasma
Jun 13 2003 02:45:23:943PM1030613016Jim Terryrepeat of 015
request: NL_04=0.5e20
actual NL_04=0.65e20 @ 0.8 s
good plasma
Jun 13 2003 02:55:20:797PM1030613017Jim Terrygo to lower density
request: NL_04=0.4e20
actual NL_04=0.60e20 @ 0.8 s
good plasma
See clear evidence of probe insertion on the diode signals.
The probe-diode correlations are not good - 20% at maximum.
The far-SOL viewing channels see a strong increase
in emission, while the channels viewing inside the
separatrix see a decrease in emission.
Possible explanation is that the probe creates local
plasma via recycling. That plasma maps to the diode views, but spreads
perppendiclual to the field as well. The reson for the decrease in
emission for the inside channels may be shadowing by this
increase in far-SOL plasma.

Jun 13 2003 02:58:17:630PM1030613018Jim Terryrepeat 017
disrupted

Jun 13 2003 03:01:36:743PM1030613019Jim Terryrepeat 017
request: NL_04=0.4e20
actual NL_04=0.56e20 @ 0.8 s
good plasma
Poor probe-diode correlation.
Again see clear evidence of probe-created plasma in the far-SOL
and shadowing for the views inside the separatrix.
Jun 13 2003 03:06:01:827PM1030613020Jim Terrydrop density
request: NL_04=0.3e20
actual NL_04=0.49e20 @ 0.8 s
good plasma
Poor probe-diode correlation.
Again see clear evidence of probe-created plasma in the far-SOL
and shadowing for the views inside the separatrix.
When the PSI triggers at 0.8 s, it sees the plasma in the
far-SOL, i.e. the blobs are close to the nozzle
Jun 13 2003 03:07:51:390PM1030613021Jim Terryrepeat 020
request: NL_04=0.3e20
actual NL_04=0.48e20 @ 0.8 s
good plasma
Poor probe-diode correlation.
Again see clear evidence of probe-created plasma in the far-SOL
and shadowing for the views inside the separatrix.
Moved PSI trigger to 0.785,i.e. before the probe-created
plasma is in the diode f-of-v. The emission (with blobs) move
inward, closer to the separatrix.
Jun 13 2003 03:22:47:487PM1030613022Jim Terryrepeat 021, but with higher I_p (800 kA).
This will destroy the mapping between probe and diodes.
request: NL_04=0.5e20
actual NL_04=0.68e20 @ 0.8 s
good plasma
No probe-diode correlation, as expected.
No probe-created plasma seen be diodes, confirming the hypotheses
that the probe creats the far-SOL plasma seen on the diodes and that that
plasma is local, mapping with the flux tube.
PSI trigger still 0.785.
Jun 13 2003 03:30:32:870PM1030613023Jim Terryno power shot
Jun 13 2003 03:30:12:277PM1030613024Jim Terryrequest higher denity, back to I_p=600 kA for which probe diode mapping exists.
MARFE - disrupts
Jun 13 2003 03:29:44:697PM1030613025Jim Terrytry again, this time ramping the density.
request: NL_04=1.0e20
actual NL_04=1.1e20 @ 0.8 s
good plasma
regained "good" (0.3-0.4) probe-diode correlation.
PSI trigger at 0.785.
Jun 13 2003 03:32:09:387PM1030613026Jim Terryrepeat 025
request: NL_04=1.0e20
actual NL_04=1.1e20 @ 0.8 s
good plasma
regained "good" (0.3-0.4) probe-diode correlation.
PSI trigger at 0.785.
Jun 13 2003 03:34:18:483PM1030613027Jim Terrygo to higher density
request: NL_04=1.1e20
actual NL_04=1.18e20 @ 0.8 s
good plasma
regained "good" (0.3-0.4) probe-diode correlation.
See classic "dipole" effect on the
diode-probe correlation function.
PSI trigger at 0.785.
Jun 13 2003 03:39:11:943PM1030613028Jim Terryrepeat 027
request: NL_04=1.1e20
actual NL_04=1.18e20 @ 0.8 s
good plasma
regained "good" (0.3-0.4) probe-diode correlation.
See classic "dipole" signature on the
diode-probe correlation function.
PSI trigger at 0.795, the time of maximum correlation.
Jun 13 2003 03:43:10:590PM1030613029Jim Terrygo to slightly higher density
request: NL_04=1.2e20
actual NL_04=1.25e20 @ 0.8 s
good plasma
Still "good" (0.3-0.4) probe-diode correlation.
See classic "dipole" signature on the
diode-probe correlation function.
PSI trigger at 0.795, the time of maximum correlation.
Jun 13 2003 03:44:02:573PM1030613030Jim Terryrepeat of 029
fizzle
Jun 13 2003 04:25:21:887PM1030613031Jim Terryrepeat of 029
request: NL_04=1.2e20
actual NL_04=1.28e20 @ 0.8 s
good plasma
Still "good" (0.3-0.4) probe-diode correlation.
See classic "dipole" signature on the
diode-probe correlation function.
PSI trigger at 0.795, the time of maximum correlation.
Jun 16 2003 08:54:32:327AM1030613032Jim Terryfizzle
Jun 13 2003 04:24:07:340PM1030613033Jim Terrygo to lower density to fill in the "turn-on" of the
probe-diode correlation.
request: NL_04=0.85e20
actual NL_04=1.0e20 @ 0.8 s
good plasma
poorer (0.15-0.25) probe-diode correlation.
PSI trigger at 0.795, the time of maximum correlation.
Jun 16 2003 08:59:16:617AM1030613033Jim Terryfill in density point around 0.95e20
request: NL_04=0.85e20
actual NL_04=1.0e20 @ 0.8 s
good plasma
Still "good" (0.3-0.4) probe-diode correlation.
Jun 13 2003 04:34:50:007PM1030613034Jim Terrygo to EDA H-mode part of the MP
request: NL_04=0.85e20, RF power stepped from 1.5 to 2.0 MW at 1. sec
actual: NL_04=1.1e20, RF tripped, no H-modes
timings are still all set around 0.8 s
Jun 13 2003 04:56:39:860PM1030613035Jim Terrytry to repeat with RF staying on
request: NL_04=0.85e20, RF power stepped from 1.5 to 2.0 MW at 1. sec
actual: NL_04=1.1e20, RF tripping, no H-modes
timings are still all set around 0.8 s
Jun 13 2003 04:58:15:503PM1030613036Jim Terrytry to repeat with RF staying on
fizzle

Physics Operator Comments
Jun 13 2003 08:58:17:297AMDmitri MossessianComntinue yesterday's runa (MP282). For details see SESSION LEADER logbook entries for yesterday.

Load 1030612006. RF from .7 s, 4 MW - attempt to repeat shots 6 taht had large ELMs driven by current
Jun 13 2003 09:06:50:760AM1030613001Dmitri MossessianNo power shot - Josh is working on some software

Next shot - try plasma
Jun 13 2003 09:36:23:310AM1030613002Dmitri MossessianGood H-mode. Only 1.3 MW of RF. No current ramp effect.

Next shot - try full RF power. Drop upper triangularity (RXU out 1 cm) and elongation (ZXU up 1 cm)
Jun 13 2003 09:57:35:070AM1030613004Dmitri MossessianRF not steady. Plasma disrupted after current ramp due to large injection (caused by RF ?)

Next shot - move beginning of RF to 0.9 s to get hotter H-mode into current ramp.
Reduce upper delta some more (RXU + 1cm). Add 2 mm ramp to RCUR at .95 s to try to compensate for current
ramp effect
Jun 13 2003 10:09:45:630AM1030613005Dmitri MossessianRF trips a lot.

Next shot - plasma seems to be stable enough and we will try to increase current ramp rate somewhat. RXU + 1cm
Add 3 mm to RCUR to increase right gap a little
Jun 13 2003 10:18:49:497AM1030613006Dmitri MossessianGood shot. Steady RF at 3.5 MW, Te_ped ~ 500 eV, good current rise. definitely no ELMs driven


Next shot - lower target density to 5e19
Jun 13 2003 10:29:59:400AM1030613007Dmitri MossessianGood shot. Target 6e19. Te_ped ~ 500 eV. Burst of ELMs between 1 and 1.04 s.

Next shot - turn current ramp OFF
Jun 13 2003 10:51:42:830AM1030613008Dmitri MossessianGood shot. Repeats shot 7 but grassy ELMs disappear.
Try to increase the effect on next couple of shots - increase RF power and drop upper delta more.

Next shot - RXU + 1cm, current ramp on. Increase current ramp rate - now ramping to .85 MA
Jun 13 2003 10:58:38:853AM1030613009Dmitri MossessianDecreasing upper delta seems to make things worse - almost no effect of current ramp seen on D-alpha.

Next shot - RXU -2 cm
Jun 13 2003 11:16:13:750AM1030613010Dmitri MossessianLost density feedback in the middle of the shot. Got max gas puff right from the beginning of H-mode.
After H-L transition density was rising and plasma disrupted at 1.46 s

Next shot - repeat with higher current ramp rate. PG4 from 23 to 21 ms
Jun 13 2003 11:26:11:697AM1030613011Dmitri MossessianBetter than 10 although still disrupted. ELMs seem to be there during Ip ramp.

This ends MP 282

Next shot - go to MP 332. Load segment 2 from 1030604010.
Jun 13 2003 11:44:37:780AM1030613012Dmitri MossessianPlasma. nl=0.8e20, asked for 0.7e20.

Next shot - CLEARIN down 5 mm
Jun 13 2003 11:59:29:487AM1030613013Dmitri MossessianPlasma. After F-probe plunge at 0.8 s edge cools down to 0 eV at 0.85 for 150 ms.

Next shot - add 10 ms to Ar (PG1). CLEARIN down 3 mm
Jun 13 2003 12:06:37:540PM1030613014Dmitri MossessianPlasma

Next shot - nl -> 5e19
Jun 13 2003 12:32:43:570PM1030613015Dmitri MossessianPlasma

Next shot - no changes
Jun 13 2003 12:32:33:697PM1030613016Dmitri MossessianPlasma

Next shot - nl -> 4e19
Jun 13 2003 12:48:20:557PM1030613017Dmitri MossessianPlasma

Next shot - CLEARIN + 2mm
Jun 13 2003 01:00:42:417PM1030613018Dmitri MossessianPlasma. Disrupted at .3 s - lost TCI feedback

Next shot - no changes
Jun 13 2003 01:12:55:163PM1030613019Dmitri MossessianPlasma.

Next shot - nl-> 3e19
Jun 13 2003 01:45:10:110PM1030613021Dmitri MossessianPlasma.

Next shot - nl -> 5e19 Ip -> 0.8 MA
Jun 13 2003 01:59:28:687PM1030613022Dmitri MossessianPlasma.

Next shot - nl -> 1e20 Ip -> 0.6 MA
Jun 13 2003 02:05:20:553PM1030613023Dmitri MossessianNo power shot. EF troubles
Jun 13 2003 02:29:02:190PM1030613024Dmitri MossessianPlasma killed by giant MARFE that starts around 0.5 s.

Next shot - slow down density rise to bring it to 1e20 by 0.8 s
Jun 13 2003 02:39:49:453PM1030613025Dmitri MossessianGood shot

Next shot - no change
Jun 13 2003 03:08:12:860PM1030613026Dmitri MossessianGood shot

Next shot - nl -> 1.1e20
Jun 13 2003 03:08:22:220PM1030613027Dmitri MossessianGood shot

Next shot - no change
Jun 13 2003 03:13:22:473PM1030613028Dmitri MossessianGood shot

Next shot - nl -> 1.2e20
Jun 13 2003 03:28:32:740PM1030613029Dmitri MossessianGood shot

Next shot - no change
Jun 13 2003 03:48:51:877PM1030613030Dmitri MossessianFizzle. Current rise too fast

Next shot - add 3 ms to PG4 21 -> 24 ms
Jun 13 2003 03:55:14:147PM1030613031Dmitri MossessianPlasma.

Next shot - nl-> 0.85e20, add 2 ms to PG4
Jun 13 2003 04:11:50:090PM1030613032Dmitri MossessianFizzle. Too much gas

Next shot - reduce PG4 (-3 ms)
Jun 13 2003 04:21:52:100PM1030613033Dmitri MossessianPlasma. Very bad startup

Next shot - nl -> 1e20
Jun 13 2003 04:32:01:363PM1030613034Dmitri MossessianPlasma. Startup is good. No H-mode - poor RF matching

Next shot -repeat
Jun 13 2003 04:59:09:970PM1030613036Dmitri MossessianFizzle

Engineering Operator Comments
ShotTimeTypeStatusComment
109:01:11:080AMTestOkdatasystem test
209:15:40:050AMPlasmaOk
309:29:20:287AMPlasmaOk
409:43:05:537AMPlasmaOk
509:56:43:567AMPlasmaOk
610:10:46:973AMPlasmaOk
710:23:38:250AMPlasmaOk
810:36:37:017AMPlasmaOk
910:52:38:003AMPlasmaOk
1011:05:33:487AMPlasmaOk
1111:19:28:033AMPlasmaOk
1211:32:15:643AMPlasmaOk
1311:45:29:830AMPlasmaOk
1412:00:03:423PMPlasmaOk
1512:15:14:317PMPlasmaOk
1612:28:39:770PMPlasmaOk
1712:41:39:957PMPlasmaOk
1812:54:22:207PMPlasmaOk
1901:07:49:410PMPlasmaOk
2001:20:59:157PMPlasmaOk
2101:34:15:970PMPlasmaOk
2201:48:12:893PMPlasmaOk
2302:01:57:923PMPlasmaBadEF1L did not charge
2402:16:57:643PMPlasmaOk
2502:30:59:973PMPlasmaOk
2602:44:18:207PMPlasmaOk
2702:57:35:880PMPlasmaOk
2803:11:16:253PMPlasmaOk
2903:24:54:910PMPlasmaOk
3003:37:39:877PMPlasmaOk
3103:50:51:877PMPlasmaOk
3204:03:33:703PMPlasmaOk
3304:16:10:690PMPlasmaOk
3404:29:05:000PMPlasmaOk
3504:41:50:950PMPlasmaOk
3604:55:04:703PMPlasmaOk