Alcator C-Mod Run 1031212 Information

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Miniproposals
Miniproposal:374
Date Filed:11/25/2003
Title:ITB dependence on triangularity
First Author:Catherine Fiore
Session Leader:Catherine Fiore (shots 1-35)

Operators
Session leader(s):Catherine Fiore
Physics operator(s):Joseph Snipes
Engineering operator(s):Gary Dekow

Engineering Operator Run Comment
MP#374 ITB dependence on triangularity SL:Fiore/Rice; PO:Snipes; EO:Deko

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:35:447PM
Author: Catherine Fiore
Session Leader Run Plan:

MP 374 ITB dependence on triangularity

Session Leader Fiore/Rice
Phys. Op.: Snipes



The purpose of this experiment is to explore the influence of the
plasma triangularity on the ITB quality, and specifically to see if
obtaining an ITB is easier, and if higher densities and better
confinement can be achieved. Reproduce ITB from 1021010004 (1-5
shots)

How we proceed depends on whether we can successfully make ITBs. From
the triangularity settings of that shot, scan up in delta_lower (0.1
increments up to 0.75, 5-8 shots)

Repeat for delta_upper holding delta_lower constant.


If a good high triangularity ITB has been established, scan target
density to optimize ITB.

It was noted from yesterday's run that radiation levels were quite high.
We believe that excess radiation kept us from successfully completing this
run on 12/2. If we can not establish an ITB this morning, we will probably
pass this run to another MP.

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

Overall, a highly successful run. Most shots have one or more ITBs, and we
achieved at least some examples at most of the triangularity conditions we
ran, including double null operation. We were able to obtain ITBs at up to 3MW
in double null operation. We demonstrated that we can still get ITBs, and we
demonstrated that we can get them fairly reliably by means of controlling the
radiated power. It appeared that it was easier to get them with higher lower
triangularity, although full analysis of the data should clarify this.

ITBs were present on shots 4, 5, 6,9, 10, 11, 12, 13, 15, 16, 17, 18, 19,
20,21, 22, 23, 27, 28, 29, 30,31,33, 34, 35

1031212001 This was a no power shot.

1031212002 This was supposed to be a fiducial shot, but not all of the rf
power supplies were on. We will tray a second one.


1031212003 Successful fiducial.
We will set up the target ITB for the next shot. RF is got back to
1.8 MW


1031212004 First attempt: H-mode with 4 back transitions. Probable ITB
forming after 1.2 s

1031212005 H-mode with 3 back transitions. ITB forms anyway after 1.15 s

1031212006 H-mode with 3 back transitions. ITB forms after 1.2 s
We will begin adjusting the triangularity on the next shot

1031212007 No H-Mode. RF problem. Plasma seems to have been limited.

1031212008 Three short H-Modes then RF cut out.
We are still trying to adjust the shape to mimic 1031209011

1031212009 Several H-Modes with 1 full drop out. The plasma was
forming a nice ITB before the back transition, from 1 s.

1031212010 Several H-Modes with 1 full drop out. The plasma was
forming a nice ITB before the back transition,from 1 s. Best ITB so far.

1031212011 Two good H-Modes with 1 full drop out. ITBs formed on both.
The first one is quite good. Lower triangularity is 0.775.
We will try adjusting the upper value.

1031212012 One good H-Modes with 1 full drop out. There is an ITB,
but not apparently better than on shot 11. We will try this again. The
upper triangularity was higher.

1031212013 It seems to be harder to sustain the H-Modes and it is
less obvious that there is an ITB. We will go one more step on the upper
triangularity.

1031212014 Many back transitions, no ITB. We pushed the upper
triangularity a little too hard and got the Xpoint touching the inner wall.
We will back off a bit.

1031212015 Several back transitions, but an ITB seems to have formed
anyway. The upper triangularity was not as high as on shot 12, but we did
get the x point off the wall. We are going back to shot 11 to test for
reproducibility.

1031212016 Nice H-mode and ITB, but the plasma disrupted. This was back
to the configuration of shot 11.

1031212017 Very similar to shot 11: Two h-modes with ITB. So far,
it seems reliable at this configuration.We will go back to shot 6 and see
if the earlier behavior is reproducible there.

1031212018 H-mode with some small back transitions and an ITB.
Somewhat better than shot 6. We will return to shot 11 and try top optimize
the ITB.

1031212019 H-mode with an ITB, probably better than shot 17. We are
going to try top optimize it, then retest the higher upper triangularity over
the next several shots.

1031212020 H-mode with an ITB, nicest one yet today. We are still
plagued with drop outs caused by rising radiation levels. We will try
doing ECDC for 10 minutes.

1031212021 H-mode with an ITB. Very similar to shot 20, despite
running ECDC. We will now return to the triangularity of shot 12. We are
remaining at slightly higher target density than for shot 12.

1031212022 H-mode with an ITB. Slower density rise that shot 21, and
takes longer before it collapses. Upper triangularity is .466

1031212023 H-mode with an ITB. Possibly less radiation. We will attempt to
run double null.

1031212024 Many H-modes, No ITB. The rf tuning was not optimal.
We achieved a double null. Oops, the field was at 5.4 T.

1031212025 H-mode started later, not too many drop outs. Possible ratty
ITB late. RF matching wasnot good, so we will repeat this and give
them a chance to tune better. We got a double null at the correct field.

1031212026 No ITB. We'll try slightly higher rf power to keep it in
H-mode.

1031212027 Double null ITB with 2.5 MW rf! No Dalsa measurement.
We'll repeat.

1031212028 Strange shot. Possible ITB, but no Dalsa. We'll repeat

1031212029 Many drop outs. Possible brief ITB before disruption.
We will try again with slightly higher power.

1031212030 ITB at 2.8 MW applied power, in double null.

1031212031 ITB at 3 MW applied power, in double null.

1031212032 Fizzle

1031212033 ITB at 2.5 MW, at high triangularity single null.

1031212034 Long lasting ITB at 2.5 MW, at high triangularity single null.
We started with a higher target density.

1031212035 Probable long lasting ITB at 3.0 MW, at high triangularity
single null, although it might not be as peaked as some of the others.

Physics Operator Summaries
Entered: Jul 7 2004 04:37:20:037PM
Author: Joseph Snipes
Engineering setup for Friday 12 Dec 2003

MP#374 --- ITB dependence on triangularity

Session leader : Fiore/Rice
Physics operator: Snipes

ECDC overnight in D2 at 2e-4 Torr, stopping by 07:00.
Bake at 60 C overnight as well.

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

Power systems the same as on 1031202024

A-coils should be hooked up as on 1031126028 (+Dtop -Dbot -Jtop +Jbot), and the power supply should be enabled.

Gas setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar Hybrid enabled (PG1)
leave B-side upper as is Hybrid DISABLED (PG2)
fill C-side with 30 psi D2 Hybrid enabled (PG3)

Enable gatevalves (there will be no vacuum problems): ECE, VUV, DNB

-------------------------------------------------------------------------------
RF Setup: All 4 transmitters in Run On by 08:00
-------------------------------------------------------------------------------

Session Leader Run Plan:

The purpose of this experiment is to explore the influence of the
plasma triangularity on the ITB quality, and specifically to see if
obtaining an ITB is easier, and if higher densities and better
confinement can be achieved. Reproduce ITB from 1021010004 (1-5
shots)

How we proceed depends on whether we can successfully make ITBs. From
the triangularity settings of that shot, scan up in delta_lower (0.1
increments up to 0.75, 5-8 shots)

Repeat for delta_upper holding delta_lower constant.


If a good high triangularity ITB has been established, scan target
density to optimize ITB.

Summary: Excellent run. We obtained all that we wanted and then some. High triangularity
does seem to improve the ITB's. We even obtained very peaked ITB's in double null
configuration with densities up to 8 x 10^20 m^-3. The machine ran very well today. The
first shot had a computer problem so there was no power. Then, there were 30 full length
plasmas in a row and finally a fizzle at 4:30 pm followed by 3 more full length plasmas.

Scorecard: 35 shots, 1 no power test, 1 fizzle, 33 full plasmas.

Shot 1: Start with an RF fiducial. Copied segment 2 from shot 1031204037.
Using startup from 1031211030 where Br0 = 0, EF4 current = -1335 A, and the
prepuff duration is 17 ms. Computer problem, no power shot.
Shot 2: Try again. Good shot. Only E port RF.
Shot 3: Try again with all the RF antennas. Got a decent 4 MW fiducial.
Shot 4: Copied segment 2 from 1021010004 and zeroed the A coil current. NINJA D2 puff
at 0.5 s. Good shot. A number of brief H-modes.
Shot 5: Increased ZXU by 1 cm to +4 cm from 0.45 s to 1.5 s to try to pull the upper X
point further away. Good shot with a number of brief H-modes.
Shot 6: Repeat to better tune the RF to be constant. Good shot got a decent ITB.
Shot 7: Increased triangularity by using settings for RCUR, ZCUR, RXL, and ZXU from shot
1031209011. Good shot, but only 0.8 MW of RF from E port. Looks like I overdid it
and reduced the outer gap to zero. Forgot to change CLEARIN when I changed RCUR.
Shot 8: Returned RCUR to 0.657 m to put the outer gap back where it was. Still RF did
not couple well.
Shot 9: Changed RCUR back to 0.666 m as on shot 1031209011 and changed CLEARIN to agree
with that shot as well at 0.008. Try again. Good shot with an ITB, but the outer
gap is down to 0.6 cm with a 2 cm inner gap.
Shot 10: Reduced RCUR by 1 mm to 0.665 m to slightly increase the outer gap and decrease
the inner gap. Good shot. Got another ITB.
Shot 11: Decreased RCUR by another mm to 0.654 m to avoid RF trip at a small outer gap.
Good shot with a nice ITB.
Shot 12: Decreased RXU by 3 cm to -0.05 m throughout the flattop to increase the upper
triangularity. Good shot. Got another ITB.
Shot 13: Repeat. Good shot. Similar to the previous one.
Shot 14: Increased ZXU by 0.02 m to 0.07 m and decreased RXU by 0.02 m to -0.07 m to
further increase the upper triangularity. Did not get increased upper
triangularity because the upper X point appears at the inner wall. No ITB.
Shot 15: Try half way in between by taking 1 cm away from RXU to -0.06 m and increased
ZXU another 0.5 cm to 0.075 m. Good shot. Perhaps a couple of minor ITB's.
Shot 16: Reload shot 1031212011. Very good shot with a long H-mode with ITB.
Disrupted at 1.25 s probably because there was too strong an ITB with
too much radiation.
Shot 17: Repeat. Good shot similar to shot 11 with an ITB.
Shot 18: Reloaded shot 1031212006 to check for reproducibility of the ITB. Good shot. Got
an ITB late in the last H-mode.
Shot 19: Reloaded shot 11 and increased nl04 to 9.5 x 10^19 m^-2. Good shot with a nice
long H-mode and ITB.
Shot 20: Increased nl04 to 1 x 10^20 m^-2. Good shot. Nice long H-mode and ITB, but the
radiation kills it by 1.12 s.
Shot 21: ECDC'd for 10 minutes before this shot to see if we could reduce the impurities a
bit to possibly extend the ITB duration. Good shot, very similar to shot 20.
Shot 22: Reloaded shot 1031212012 and increased nl04 to 1 x 10^20 m^-2. Brief delay for
Irby to adjust the TCI. Good shot. Nice long H-mode with ITB.
Shot 23: Repeat with nl04 = 1.05 x 10^20 m^-2. Good shot. Long H-mode with weaker ITB.
Shot 24: Loaded segment 4 from shot 1031125018 to go to double null. Raised nl04 to
1 x 10^20 m^-2. Good shot. Several brief H-modes with only just over 1 MW of RF.
I did not reduce the field to get the ITB's since I just copied that segment from
the old shot, which was at 5.4 T.
Shot 25: Changed the TF to be similar to the previous shots today at go to 4.55 T.
Several H-modes with no ITB.
Shot 26: Repeat to tune the RF. Several brief H-modes. No ITB.
Shot 27: Repeat with higher RF power since the threshold in double null may be higher.
Nice ITB in double null with the highest density yet today.
Shot 28: Repeat to get TCI data. Not repeatable. Instead there were multiple H-modes and
RF trips with perhaps a weak ITB.
Shot 29: Repeat to get dalsa data. Decent shot similar to shot 28 perhaps with a weak ITB.
Shot 30: Repeat to get more RF power. Good shot with a nice ITB.
Shot 31: Repeat. Good shot again with a very peaked ITB at the end just before the
disruption.
Shot 32: Reloaded shot 1031212012 and raised nl04 to 1.05 x 10^20 m^-2. Raise RF to 2.5 MW.
Fizzle!
Shot 33: Repeat. Good shot. Long H-mode but not such a strong ITB this time.
Shot 34: Added 50 V pre-programmed gas early on pulse gas 3 to try to raise the target
density a bit more. Really long H-mode with a nice ITB.
Shot 35: Repeat with more RF power. Good shot with a nice long H-mode with ITB and 3 MW
of RF.



Session Leader Comments
Dec 12 2003 08:24:10:483AMCatherine FioreSession Leader Run Plan:

MP 374 ITB dependence on triangularity

Session Leader Fiore/Rice
Phys. Op.: Snipes



The purpose of this experiment is to explore the influence of the
plasma triangularity on the ITB quality, and specifically to see if
obtaining an ITB is easier, and if higher densities and better
confinement can be achieved. Reproduce ITB from 1021010004 (1-5
shots)

How we proceed depends on whether we can successfully make ITBs. From
the triangularity settings of that shot, scan up in delta_lower (0.1
increments up to 0.75, 5-8 shots)

Repeat for delta_upper holding delta_lower constant.


If a good high triangularity ITB has been established, scan target
density to optimize ITB.

It was noted from yesterday's run that radiation levels were quite high.
We believe that excess radiation kept us from successfully completing this
run on 12/2. If we can not establish an ITB this morning, we will probably
pass this run to another MP.
Dec 12 2003 09:27:11:883AM1031212001Catherine FioreThis was a no power shot.

Dec 12 2003 09:28:34:617AM1031212002Catherine FioreThis was supposed to be a fiducial shot, but not all of the rf
power supplies were on. We will tray a second one.

Dec 12 2003 09:41:06:387AM1031212003Catherine FioreSuccessful fiducial.

We will set up the target ITB for the next shot. RF is got back to
1.8 MW
Dec 12 2003 10:01:38:427AM1031212004Catherine FioreFirst attempt: H-mode with 4 back transitions. Probable ITB forming after
1.2 s
Dec 12 2003 10:11:17:820AM1031212005Catherine FioreH-mode with 3 back transitions. ITB forms anyway after 1.15 s
Dec 12 2003 10:27:32:827AM1031212006Catherine FioreH-mode with 3 back transitions. ITB forms after 1.2 s

We will begin adjusting the triangularity on the next shot
Dec 12 2003 10:42:45:460AM1031212007Catherine FioreNo H-Mode. RF problem.

Plasma seems to have been limited.

Dec 12 2003 10:52:33:713AM1031212008Catherine FioreThree short H-Modes then RF cut out.

We are still trying to adjust the shape to mimic 1031209011
Dec 12 2003 11:10:08:843AM1031212009Catherine FioreSeveral H-Modes with 1 full drop out. The plasma was forming a nice ITB before the back transition,
from 1 s.


Dec 12 2003 11:23:09:787AM1031212010Catherine FioreSeveral H-Modes with 1 full drop out. The plasma was forming a nice ITB before the back transition,
from 1 s. Best ITB so far.


Dec 12 2003 11:40:55:827AM1031212011Catherine FioreTwo good H-Modes with 1 full drop out. ITBs formed on both. The first one is quite good.
Lower triangularity is 0.775. We will try adjusting the upper value.

Dec 12 2003 11:54:25:343AM1031212012Catherine FioreOne good H-Modes with 1 full drop out. There is an ITB, but not apparently better than on shot 11.
We will try this again. The upper triangularity was higher.
Dec 12 2003 12:02:25:050PM1031212013Catherine FioreIt seems to be harder to sustain the H-Modes and it is less obvious that there is an ITB. We will go one more
step on the upper triangularity.
Dec 12 2003 12:14:20:900PM1031212014Catherine FioreMany back transitions, no ITB. We pushed the upper triangularity a little too hard and got the Xpoint
touching the inner wall. We will back off a bit.
Dec 12 2003 12:29:45:500PM1031212015Catherine FioreSeveral back transitions, but an ITB seems to have formed anyway. The upper
triangularity was not as high as on shot 12, but we did get the x point off the
wall. We are going back to shot 11 to test for reproducibility.
Dec 12 2003 12:38:24:550PM1031212016Catherine FioreNice H-mode and ITB, but the plasma disrupted. This was back to the configuration of shot 11.
Dec 12 2003 12:54:22:807PM1031212017Catherine FioreVery similar to shot 11: Two h-modes with ITB. So far, it seems reliable at this configuration.

We will go back to shot 6 and see if the earlier behavior is reproducible there.
Dec 12 2003 01:08:45:500PM1031212018Catherine FioreH-mode with some small back transitions and an ITB. Somewhat better than shot 6.
We will return to shot 11 and try top optimize the ITB.
Dec 12 2003 01:21:09:160PM1031212019Catherine FioreH-mode with an ITB, probably better than shot 17. We are going to try top optimize it, then
retest the higher upper triangularity over the next several shots.
Dec 12 2003 01:31:36:303PM1031212020Catherine FioreH-mode with an ITB, nicest one yet today. We are still plagued with drop outs
caused by rising radiation levels. We will try doing ECDC for 10 minutes.
Dec 12 2003 01:57:34:063PM1031212021Catherine FioreH-mode with an ITB. Very similar to shot 20, despite running ECDC.
We will now return to the triangularity of shot 12. We are remaining
at slightly higher target density than for shot 12.
Dec 12 2003 02:27:23:043PM1031212022Catherine FioreH-mode with an ITB. Slower density rise that shot 21, and takes longer
before it collapses. Upper triangularity is .466
Dec 12 2003 02:39:45:770PM1031212023Catherine FioreH-mode with an ITB. Possibly less radiation. We will attempt to
run double null.
Dec 12 2003 02:54:41:307PM1031212024Catherine FioreMany H-modes, No ITB. The rf tuning was not optimal.
We achieved a double null. Oops, the field was at 5.4 T.
Dec 12 2003 03:01:19:963PM1031212025Catherine FioreH-mode started later, not too many drop outs. Possible ratty ITB late.
RF matching wasnot good, so we will repeat this and give them a chance to tune
better. We got a double null at the correct field.
Dec 12 2003 03:25:44:800PM1031212026Catherine FioreNo ITB. We'll try slightly higher rf power to keep it in H-mode.
Dec 12 2003 03:43:00:183PM1031212027Catherine FioreDouble null ITB with 2.5 MW rf! No Dalsa measurement.
We'll repeat.
Dec 12 2003 03:41:53:853PM1031212028Catherine FioreStrange shot. Possible ITB, but no Dalsa. We'll repeat.
Dec 12 2003 03:54:07:297PM1031212029Catherine FioreMany drop outs. Possible brief ITB before disruption. We will try again with
slightly higher power.
Dec 12 2003 04:07:42:113PM1031212030Catherine FioreITB at 2.8 MW applied power, in double null.
Dec 12 2003 04:24:18:153PM1031212031Catherine FioreITB at 3 MW applied power, in double null.
Dec 12 2003 04:24:32:557PM1031212032Catherine FioreFizzle
Dec 12 2003 04:43:23:300PM1031212033Catherine FioreITB at 2.5 MW, at high triangularity single null.
Dec 12 2003 04:57:25:460PM1031212034Catherine FioreLong lasting ITB at 2.5 MW, at high triangularity single null. We
started with a higher target density.
Dec 12 2003 05:06:31:200PM1031212035Catherine FioreLong lasting ITB at 3.0 MW, at high triangularity single null, although
it might not be as peaked as some of the others.
Dec 12 2003 05:11:09:153PM1031212035Catherine FioreProbable long lasting ITB at 3.0 MW, at high triangularity single null, although
it might not be as peaked as some of the others.

Physics Operator Comments
Dec 12 2003 08:19:07:717AMJoseph SnipesEngineering setup for Friday 12 Dec 2003

MP#374 --- ITB dependence on triangularity

Session leader : Fiore/Rice
Physics operator: Snipes

ECDC overnight in D2 at 2e-4 Torr, stopping by 07:00.
Bake at 60 C overnight as well.

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

Power systems the same as on 1031202024

A-coils should be hooked up as on 1031126028 (+Dtop -Dbot -Jtop +Jbot), and the power supply should be enabled.

Gas setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar Hybrid enabled (PG1)
leave B-side upper as is Hybrid DISABLED (PG2)
fill C-side with 30 psi D2 Hybrid enabled (PG3)

Enable gatevalves (there will be no vacuum problems): ECE, VUV, DNB

-------------------------------------------------------------------------------
RF Setup: All 4 transmitters in Run On by 08:00
-------------------------------------------------------------------------------

Session Leader Run Plan:

The purpose of this experiment is to explore the influence of the
plasma triangularity on the ITB quality, and specifically to see if
obtaining an ITB is easier, and if higher densities and better
confinement can be achieved. Reproduce ITB from 1021010004 (1-5
shots)

How we proceed depends on whether we can successfully make ITBs. From
the triangularity settings of that shot, scan up in delta_lower (0.1
increments up to 0.75, 5-8 shots)

Repeat for delta_upper holding delta_lower constant.


If a good high triangularity ITB has been established, scan target
density to optimize ITB.
Dec 12 2003 09:28:08:960AM1031212001Joseph SnipesShot 1: Start with an RF fiducial. Copied segment 2 from shot 1031204037.
Using startup from 1031211030 where Br0 = 0, EF4 current = -1335 A, and the
prepuff duration is 17 ms. Computer problem, no power shot.
Dec 12 2003 09:28:19:540AM1031212002Joseph SnipesShot 2: Try again. Good shot. Only E port RF.
Dec 12 2003 09:38:54:560AM1031212003Joseph SnipesShot 3: Try again with all the RF antennas. Got a decent 4 MW fiducial.
Dec 12 2003 09:52:36:533AM1031212004Joseph SnipesShot 4: Copied segment 2 from 1021010004 and zeroed the A coil current. NINJA D2 puff
at 0.5 s. Good shot. A number of brief H-modes.
Dec 12 2003 10:05:31:540AM1031212005Joseph SnipesShot 5: Increased ZXU by 1 cm to +4 cm from 0.45 s to 1.5 s to try to pull the upper X
point further away. Good shot with a number of brief H-modes.
Dec 12 2003 10:33:35:457AM1031212006Joseph SnipesShot 6: Repeat to better tune the RF to be constant. Good shot got a decent ITB.
Dec 12 2003 10:47:53:397AM1031212007Joseph SnipesShot 7: Increased triangularity by using settings for RCUR, ZCUR, RXL, and ZXU from shot
1031209011. Good shot, but only 0.8 MW of RF from E port. Looks like
I overdid it and reduced the outer gap to zero. Forgot to change
CLEARIN when I changed RCUR.
Dec 12 2003 10:55:24:603AM1031212008Joseph SnipesShot 8: Returned RCUR to 0.657 m to put the outer gap back where it was. Still RF did
not couple well.
Dec 12 2003 11:09:15:407AM1031212009Joseph SnipesShot 9: Changed RCUR back to 0.666 m as on shot 1031209011 and changed CLEARIN to agree
with that shot as well at 0.008. Try again. Good shot with an ITB, but the outer
gap is down to 0.6 cm with a 2 cm inner gap.
Dec 12 2003 11:18:33:580AM1031212010Joseph SnipesShot 10: Reduced RCUR by 1 mm to 0.665 m to slightly increase the outer gap and decrease
the inner gap. Good shot. Got another ITB.
Dec 12 2003 11:36:03:730AM1031212011Joseph SnipesShot 11: Decreased RCUR by another mm to 0.654 m to avoid RF trip at a small outer gap.
Good shot with a nice ITB.
Dec 12 2003 11:42:50:450AM1031212012Joseph SnipesShot 12: Decreased RXU by 3 cm to -0.05 m throughout the flattop to increase the upper
triangularity. Good shot. Got another ITB.
Dec 12 2003 11:55:41:500AM1031212013Joseph SnipesShot 13: Repeat. Good shot. Similar to the previous one.
Dec 12 2003 12:12:34:773PM1031212014Joseph SnipesShot 14: Increased ZXU by 0.02 m to 0.07 m and decreased RXU by 0.02 m to -0.07 m to
further increase the upper triangularity. Did not get increased upper
triangularity because the upper X point appears at the inner wall. No ITB.
Dec 12 2003 12:26:56:297PM1031212015Joseph SnipesShot 15: Try half way in between by taking 1 cm away from RXU to -0.06 m and increased
ZXU another 0.5 cm to 0.075 m. Good shot. Perhaps a couple of minor ITB's.
Dec 12 2003 12:38:17:033PM1031212016Joseph SnipesShot 16: Reload shot 1031212011. Very good shot with a long H-mode with ITB.
Disrupted at 1.25 s probably because there was too strong an ITB with
too much radiation.
Dec 12 2003 12:49:37:273PM1031212017Joseph SnipesShot 17: Repeat. Good shot similar to shot 11 with an ITB.
Dec 12 2003 01:03:08:293PM1031212018Joseph SnipesShot 18: Reloaded shot 1031212006 to check for reproducibility of the ITB. Good shot. Got
an ITB late in the last H-mode.
Dec 12 2003 01:15:59:330PM1031212019Joseph SnipesShot 19: Reloaded shot 11 and increased nl04 to 9.5 x 10^19 m^-2. Good shot with a nice
long H-mode and ITB.
Dec 12 2003 01:30:53:977PM1031212020Joseph SnipesShot 20: Increased nl04 to 1 x 10^20 m^-2. Good shot. Nice long H-mode and ITB, but the
radiation kills it by 1.12 s.
Dec 12 2003 01:54:17:440PM1031212021Joseph SnipesShot 21: ECDC'd for 10 minutes before this shot to see if we could reduce the impurities a
bit to possibly extend the ITB duration. Good shot, very similar to shot 20.
Dec 12 2003 02:17:15:180PM1031212022Joseph SnipesShot 22: Reloaded shot 1031212012 and increased nl04 to 1 x 10^20 m^-2. Brief delay for
Irby to adjust the TCI. Good shot. Nice long H-mode with ITB.
Dec 12 2003 02:31:24:297PM1031212023Joseph SnipesShot 23: Repeat with nl04 = 1.05 x 10^20 m^-2. Good shot. Long H-mode with weaker ITB.
Dec 12 2003 02:49:31:023PM1031212024Joseph SnipesShot 24: Loaded segment 4 from shot 1031125018 to go to double null. Raised nl04 to
1 x 10^20 m^-2. Good shot. Several brief H-modes with only just over 1 MW of RF.
I did not reduce the field to get the ITB's since I just copied that segment from
the old shot, which was at 5.4 T.
Dec 12 2003 02:57:04:243PM1031212025Joseph SnipesShot 25: Changed the TF to be similar to the previous shots today at go to 4.55 T.
Several H-modes with no ITB.
Dec 12 2003 03:11:13:513PM1031212026Joseph SnipesShot 26: Repeat to tune the RF. Several brief H-modes. No ITB.
Dec 12 2003 03:23:22:190PM1031212027Joseph SnipesShot 27: Repeat with higher RF power since the threshold in double null may be higher.
Nice ITB in double null with the highest density yet today.
Dec 12 2003 03:37:13:320PM1031212028Joseph SnipesShot 28: Repeat to get TCI data. Not repeatable. Instead there were multiple H-modes and
RF trips with perhaps a weak ITB.
Dec 12 2003 03:48:32:810PM1031212029Joseph SnipesShot 29: Repeat to get dalsa data. Decent shot similar to shot 28 perhaps with a weak ITB.
Dec 12 2003 03:59:35:313PM1031212030Joseph SnipesShot 30: Repeat to get more RF power. Good shot with a nice ITB.
Dec 12 2003 04:14:52:617PM1031212031Joseph SnipesShot 31: Repeat. Good shot again with a very peaked ITB at the end just before the
disruption.
Dec 12 2003 04:42:57:050PM1031212033Joseph SnipesShot 33: Repeat. Good shot. Long H-mode but not such a strong ITB this time.
Dec 12 2003 04:53:18:520PM1031212034Joseph SnipesShot 34: Added 50 V pre-programmed gas early on pulse gas 3 to try to raise the target
density a bit more. Really long H-mode with a nice ITB.
Dec 12 2003 05:04:20:450PM1031212035Joseph SnipesShot 35: Repeat with more RF power. Good shot with a nice long H-mode with ITB and 3 MW
of RF.
Dec 12 2003 05:05:58:980PM1031212035Joseph SnipesSummary: Excellent run. We obtained all that we wanted and then some. High triangularity
does seem to improve the ITB's. We even obtained very peaked ITB's in double null
configuration with densities up to 8 x 10^20 m^-3. The machine ran very well today. The
first shot had a computer problem so there was no power. Then, there were 30 full length
plasmas in a row and finally a fizzle at 4:30 pm followed by 3 more full length plasmas.

Scorecard: 35 shots, 1 no power test, 1 fizzle, 33 full plasmas.

Engineering Operator Comments
ShotTimeTypeStatusComment
109:11:09:737AMTestBad
209:22:54:913AMPlasmaOk
309:34:49:027AMPlasmaOk
409:50:20:877AMPlasmaOk
510:02:57:507AMPlasmaOk
610:18:37:887AMPlasmaOk
710:33:46:410AMPlasmaOk
810:47:34:460AMPlasmaOk
911:00:06:730AMPlasmaOk
1011:14:30:847AMPlasmaOk
1111:26:56:833AMPlasmaOk
1211:39:25:510AMPlasmaOk
1311:51:57:487AMPlasmaOk
1412:04:23:740PMPlasmaOk
1512:20:32:277PMPlasmaOk
1612:33:05:673PMPlasmaOk
1712:45:31:537PMPlasmaOk
1812:58:18:810PMPlasmaOk
1901:11:05:577PMPlasmaOk
2001:23:45:287PMPlasmaOk
2101:50:44:297PMPlasmaOk
2202:13:03:633PMPlasmaOk
2302:27:06:357PMPlasmaOk
2402:39:46:427PMPlasmaOk
2502:52:24:240PMPlasmaOk
2603:05:02:857PMPlasmaOk
2703:17:41:877PMPlasmaOk
2803:30:38:147PMPlasmaOk
2903:43:27:293PMPlasmaOk
3003:56:12:267PMPlasmaOk
3104:09:00:550PMPlasmaOk
3204:21:51:620PMPlasmaOk
3304:34:36:563PMPlasmaOk
3404:47:23:643PMPlasmaOk
3505:00:11:197PMPlasmaOk