Alcator C-Mod Run 980204 Information

Miniproposals

Miniproposal: 143b

Date Filed: 12/12/1997

Title: Triangularity Scan in H-Mode (143 revised)

First Author: Martin Greenwald

Session Leader: Martin Greenwald (shots 1-41)

Operators
Session leader(s):	Martin Greenwald
Physics operator(s):	Ian Hutchinson
Engineering operator(s):	Unknown

Engineering Operator Run Comment
mp 143b

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Entered: Jul 7 2004 03:49:17:960PM

Author: To Be Determined

Run Summary for 980204
Triangularity Scan MP 143b

Session Leader: Greenwald
Phys Op: Hutchinson

============================

Plan:

The general approach is to run a given equilibrium then scan the target
density/gas puff to find (if possible) the ELMfree/EDA boundary. Prf
will be fixed somewhere between 2 - 2.5 MW.

For equilibria,

1. start with our normal shape.

2. Keeping the lower triangularity fixed at 0.54, scan the upper
triangularity between its minimum and maximum (at least 0.2-0.6).

3. With the upper triangularity fixed at ?, scan the lower triangularity
from (around) 0.4 to 0.65

4. If time permits pursue most promising part of the remaining
operating space.

==============================

Results:

A productive day. We ran cases at 3 different upper triangularities,
[.16,.4,.62], and 3 different lower triangularities, [.4,.5,.6].
Density scans were performed at each. At the end of the day continuous
triangularity scans were performed at fixed density. In the first,
delta_l = .6->.4 and delta_u = .35->.17; for the second only delta_u
was scanned = .5->.2

A wide variety of H-mode types were observed. There is apparently
a great deal of operating space in between pure ELMfree and pure
steady EDA. Using the appearance of a steady EDA as a measure,
we find that it requires the highest densities and divertor pressures
when the triangularity is low, and less for the moderate and higher
triangularities.

Xray pedestal widths seem to be a good metric for h-mode phase. In all
cases it is narrower for ELMfree, wider for the mixed modes, and widest
for EDA. The scans on shots 40 and 41 showed that the width also
responds to triangularity independent of confinement mode and in the
same sense. As the triangularity scanned down, the width decreases, all
in EDA - later, as the confinement mode switches to ELMfree, the width
continues to narrow.

================================

Shots suitable for further analysis include:

Shot delta_u delta_l
980204002 .32 .51
980204004 .17 .50
980204005 .17 .50
980204006 .16 .51
980204007 .16 .50
980204008 .17 .50
980204009 .15 .50
980204010 .36 .50
980204011 .40 .50
980204015 .40 .50
980204016 .60 .50
980204017 .60 .50
980204018 .60 .50
980204019 .60 .50
980204020 .60 .50
980204021 .40 .50
980204022 .40 .50
980204023 .35 .64
980204024 .36 .63
980204035 .40 .40
980204036 .40 .40
980204038 .20 .40
980204039 .20 .40
980204040 .35->.18 .6->.4
980204041 .47->.2 .52

Physics Operator Summaries

Entered: Jul 7 2004 04:36:58:957PM

Author: To Be Determined

Physop Report 980204 MP 143B Triangularity Effects on H-mode.
____________________________________________________________

Summary
_______

Excellent data was obtained on the topic.

Steady state confinement data and H-modes were obtained for two or three
different densities over the matrix of High, Normal, and Low triangularities
at the top and bottom. (9 cases, but some already exist).

In addition, at the end of the run, a dynamic scan of triangularities:
top/bottom simultaneously (shot 40) and top only (shot 41) was
done. Shot 40 showed dramatically how scanning the x-point outwards,
thus lowering the triangularity, caused an H-mode that starts with
large D-alpha enhancement gradually to become ELM-free.

I claim a new PHYSOP RECORD for Fizzle-less plasma operations. Forty
plasmas one power-supply dud, no fizzles, no duds. Shot 26 was a
plasma but the data was lost. In fairness to Earl, who was fizzop
yesterday, I changed practically nothing to achieve this.

Scorecard.
__________ Shot,Duration(s),Ipmax(MA) Shot,Duration(s),Ipmax
1 1.604 0.833 2 1.679 1.030
3 0.739 1.077 4 1.521 1.035
5 1.549 1.035 6 1.526 1.024
7 1.568 1.035 8 1.534 1.040
9 1.644 1.040 10 1.675 1.040
11 1.678 1.040 12 0.580 1.091
13 1.668 1.035 14 1.667 1.035
15 1.674 1.040 16 1.673 1.035
17 1.393 1.040 18 1.678 1.040
19 1.680 1.040 20 1.673 1.040
21 1.678 1.040 22 1.681 1.040
23 1.672 1.037 24 1.669 1.029
25 1.527 1.004No Ip 26
27 1.509 1.004 28 1.619 1.017
29 1.619 1.017 30 1.660 0.833
31 0.000 0.005 32 0.133 0.544
33 1.634 1.027 34 1.680 1.040
35 1.684 1.040 36 1.680 1.035
37 1.674 1.019 38 1.694 1.040
39 1.673 1.040 40 1.671 1.029
41 1.447 1.029
Finished summary for 980204 Total of 41 shots.
41 shots. 40 plasmas. 0 fizzles. 1 ps-duds.

Details
_______

--------------------------------------------------------------------------------
980204xxx HUTCH PHYSICS_OPERATOR 4-FEB-1998 08:33:39.03
. . . . . . . . . . . . . . . . . . . .
Triangularity Scan 143B
Trying to see what effect shape has on the EDA effects.

Cold Start.
Load 980103006 oops. Mistake.
PCS brings my station to a freeze and then blows itself away!
Restart from DCL prompt.
Try to load 980203006.
OK.
--------------------------------------------------------------------------------
980204001 HUTCH PHYSICS_OPERATOR 4-FEB-1998 08:51:27.59
. . . . . . . . . . . . . . . . . . . .
Plasma. Fiducial.
--------------------------------------------------------------------------------
980204002 HUTCH PHYSICS_OPERATOR 4-FEB-1998 09:09:46.48
. . . . . . . . . . . . . . . . . . . .
Switch to segment 2.
Plasma. This is a strange shot left over from Wolfe.
Not recommended method of control because this had
strikepsi etc, But actually gives a nice long EDA mode.

Remove STrikepsi gain.
REturn zxl gain to 8 throughout.
Adjust rxl to be out earlier.
--------------------------------------------------------------------------------
980204003 HUTCH PHYSICS_OPERATOR 4-FEB-1998 09:23:32.16
. . . . . . . . . . . . . . . . . . . .
Plasma. Disrupts at .74s. Brick.
A bit too slot-like.

Copy TF from segment 2 to segment 1.
ZXL to 0 from -.017. Try to make less slotty.
RXU to .03 from -.02. Reduce the upper triangularity.
Copy TF from segment 4 to 2 and 1. Want 5.4T.
--------------------------------------------------------------------------------
980204004 HUTCH PHYSICS_OPERATOR 4-FEB-1998 09:36:50.53
. . . . . . . . . . . . . . . . . . . .
Plasma. Lots of little H-modes. Strange H-alpha behaviour.

Rcur to .668 from .669.
--------------------------------------------------------------------------------
980204005 HUTCH PHYSICS_OPERATOR 4-FEB-1998 09:48:05.06
. . . . . . . . . . . . . . . . . . . .
Plasma.

Target density to nl04=1.5,
rcur to .667.
--------------------------------------------------------------------------------
980204006 HUTCH PHYSICS_OPERATOR 4-FEB-1998 10:04:40.42
. . . . . . . . . . . . . . . . . . . .
Plasma. Nearly killed it in the current rise, but recovered.

EF4 to -1340 from -1345.
nl04 to 1.8.
--------------------------------------------------------------------------------
980204007 HUTCH PHYSICS_OPERATOR 4-FEB-1998 10:16:30.74
. . . . . . . . . . . . . . . . . . . .
Plasma. Fuelled quite effectively till RF turn-on.
Then 2 H-modes of different character.

Lower target density to .6.
--------------------------------------------------------------------------------
980204008 HUTCH PHYSICS_OPERATOR 4-FEB-1998 10:31:21.68
. . . . . . . . . . . . . . . . . . . .
Plasma. Lower density. Goy .85 target.
Multiple H-modes with impurity accumulation.

Call the zcur predictors.
--------------------------------------------------------------------------------
980204009 HUTCH PHYSICS_OPERATOR 4-FEB-1998 10:44:29.17
. . . . . . . . . . . . . . . . . . . .
Plasma. Some hards. Didn't get much lower density.
RF has some problems.

EF4 to -1335.
RXU to -.04.
Argon puff to 25ms from 35.
--------------------------------------------------------------------------------
980204010 HUTCH PHYSICS_OPERATOR 4-FEB-1998 10:57:23.30
. . . . . . . . . . . . . . . . . . . .
Plasma. Still hards.

EF4 to -1330.
Zcur to -.01 from .015.
--------------------------------------------------------------------------------
980204011 HUTCH PHYSICS_OPERATOR 4-FEB-1998 11:10:43.73
. . . . . . . . . . . . . . . . . . . .
Plasma.

Load nl04 wire 14 from shot 6. High density.
--------------------------------------------------------------------------------
980204012 HUTCH PHYSICS_OPERATOR 4-FEB-1998 11:20:15.61
. . . . . . . . . . . . . . . . . . . .
Plasma. Disrupts at .57s. Strange effect at .5s after soaking up
the gas quite nicely. Perhaps that is the poloidal detachment ending.
Then hit by a brick.
--------------------------------------------------------------------------------
980204013 HUTCH PHYSICS_OPERATOR 4-FEB-1998 11:35:14.62
. . . . . . . . . . . . . . . . . . . .
Plasma.

Lower nl04 a tad in the first .5s to reduce the detachment etc.
--------------------------------------------------------------------------------
980204014 HUTCH PHYSICS_OPERATOR 4-FEB-1998 11:46:58.25
. . . . . . . . . . . . . . . . . . . .
Plasma. Density is even higher.

Lower nl04 target to 1.
--------------------------------------------------------------------------------
980204016 HUTCH PHYSICS_OPERATOR 4-FEB-1998 12:13:33.96
. . . . . . . . . . . . . . . . . . . .
Plasma. Nicely sustained EDA.

RXU to -.07m to increase the upper triangularity some more.
IC_ef4 to 2000A.

plasma. Looks like one long EDA. Triangularity up to 0.6.

Next shot, drop nl4 to .7e20.
--------------------------------------------------------------------------------
980204017 HUTCH PHYSICS_OPERATOR 4-FEB-1998 12:26:52.52
. . . . . . . . . . . . . . . . . . . .
Shot 17: Drop nl4 to .7e20
(wolfe sitting in as physop)

plasma disrupts at 1.39 sec, pf breaker pulled. ef1l crowbarred at 1.28sec
Target gets to .9e20.
Wplasm is decaying, starts almost Elm-free, then EDA increases solwly.

Next shot, just repeat and see if density comes down some more.
--------------------------------------------------------------------------------
980204018 HUTCH PHYSICS_OPERATOR 4-FEB-1998 12:39:08.43
. . . . . . . . . . . . . . . . . . . .
Shot 18: repeat.
Note that we are puffing into the H-mode, since there is a 50V level on PG3 and the nl4 program
goes up to 1.7e20.

Target still at .9
ELM-free until .78sec, then EDA after the H-L/injection.

Next shot, Reduce PG3 voltage program from 50V to 30V after .425sec
--------------------------------------------------------------------------------
980204019 HUTCH PHYSICS_OPERATOR 4-FEB-1998 12:51:21.13
. . . . . . . . . . . . . . . . . . . .
Shot 19: Reduce PG3 voltage program from 50V to 30V after .425sec

Target density still not dropping
Starts ELM-free, then H=L with 2pi at 2MW, then comes back as EDA.

One more try at lowering the density.
--------------------------------------------------------------------------------
980204020 HUTCH PHYSICS_OPERATOR 4-FEB-1998 13:00:26.65
. . . . . . . . . . . . . . . . . . . .
Shot 20: Reduce PG3 voltage program from 30V to 0. after .425
Target density to .64 early (from .75)

3 h-modes, got the lower density this time.
Next shot, back to shot 11.
--------------------------------------------------------------------------------
980204021 HUTCH PHYSICS_OPERATOR 4-FEB-1998 13:15:24.56
. . . . . . . . . . . . . . . . . . . .
Shot 21: Import Segment 2 from shot 11 (and rename the segment)
Plasma. nl04 .8 target. EDA for .35s but with significant radiation.

Lower PG3 gas puff to 10 from 50V.
--------------------------------------------------------------------------------
980204022 HUTCH PHYSICS_OPERATOR 4-FEB-1998 13:38:21.51
. . . . . . . . . . . . . . . . . . . .
Plasma. True ELM-free phase to start with.

RXL to -.025m. Increase x-point triangularity.
--------------------------------------------------------------------------------
980204023 HUTCH PHYSICS_OPERATOR 4-FEB-1998 13:44:20.74
. . . . . . . . . . . . . . . . . . . .
Plasma. Got triangularity of .6. X-point just off the inner nose.
ELM-free with increasing H-alpha later, but all with radiation.

Raise nl04 to 1. Raise gas puff to 50V.
--------------------------------------------------------------------------------
980204024 HUTCH PHYSICS_OPERATOR 4-FEB-1998 13:56:02.23
. . . . . . . . . . . . . . . . . . . .
Plasma. Sustained EDA. Got 1.1 target. Still serious radiation.

nl04 to 1.6.
--------------------------------------------------------------------------------
980204025 HUTCH PHYSICS_OPERATOR 4-FEB-1998 14:07:13.16
. . . . . . . . . . . . . . . . . . . .
Plasma. No RF
Enormous amounts of gas injected. Slow density ramp.
No marfe after .3s.

Repeat.
--------------------------------------------------------------------------------
980204026 HUTCH PHYSICS_OPERATOR 4-FEB-1998 14:29:27.63
. . . . . . . . . . . . . . . . . . . .
Plasma. No RF again.
DAQA reboots itself. No data.

Lower the nl04.
RXL to +.02.
--------------------------------------------------------------------------------
980204027 HUTCH PHYSICS_OPERATOR 4-FEB-1998 14:38:18.51
. . . . . . . . . . . . . . . . . . . .
Plasma. Looks like I forgot to load. No RF.

Load.
--------------------------------------------------------------------------------
980204028 HUTCH PHYSICS_OPERATOR 4-FEB-1998 14:53:16.59
. . . . . . . . . . . . . . . . . . . .
Plasma. No RF.

RXU to -.05. G wants higher.
RXL to +.03m.
--------------------------------------------------------------------------------
980204029 HUTCH PHYSICS_OPERATOR 4-FEB-1998 15:06:32.20
. . . . . . . . . . . . . . . . . . . .
Plasma. RF seems able to coule at the end, but they report
strange loading.

Reenable fiducial segment.
--------------------------------------------------------------------------------
980204030 HUTCH PHYSICS_OPERATOR 4-FEB-1998 15:15:36.02
. . . . . . . . . . . . . . . . . . . .
Plasma. Seems ok for the RF.

Back to the triangularity shot.
--------------------------------------------------------------------------------
980204031 HUTCH PHYSICS_OPERATOR 4-FEB-1998 15:23:24.22
. . . . . . . . . . . . . . . . . . . .
Power supply dud. Magnet resistance fault.
--------------------------------------------------------------------------------
980204032 HUTCH PHYSICS_OPERATOR 4-FEB-1998 15:31:58.35
. . . . . . . . . . . . . . . . . . . .
Plasma lasts till 100ms. Seems like a brick.

--------------------------------------------------------------------------------
980204033 HUTCH PHYSICS_OPERATOR 4-FEB-1998 15:43:20.13
. . . . . . . . . . . . . . . . . . . .
Plasma. Got 2+MW, but no H-mode. Some heating. Low radiation.

Lower nl04 to .6, Gas puff to 10V.
--------------------------------------------------------------------------------
980204034 HUTCH PHYSICS_OPERATOR 4-FEB-1998 15:53:58.40
. . . . . . . . . . . . . . . . . . . .
Plasma. Multiple ELM-free H-modes. But the RF trips off.

Lower PG3 a tad at .25s.
--------------------------------------------------------------------------------
980204035 HUTCH PHYSICS_OPERATOR 4-FEB-1998 16:01:40.48
. . . . . . . . . . . . . . . . . . . .
Plasma. Multiple H-modes, ELM-Free. RF stays on better but still bad.

nl04 to .8.
--------------------------------------------------------------------------------
980204036 HUTCH PHYSICS_OPERATOR 4-FEB-1998 16:15:25.03
. . . . . . . . . . . . . . . . . . . .
Plasma. Multiple ELM-free H-modes.
RF 1.4MW.

nl04 to 1.1, puff V to 30V.
--------------------------------------------------------------------------------
980204037 HUTCH PHYSICS_OPERATOR 4-FEB-1998 16:22:21.71
. . . . . . . . . . . . . . . . . . . .
Plasma L-mode. Target 1e20!
Pretty clear that these low-xpoint-triangularity shots have a higher
H-mode trheshold power and tetnd to stay in ELM-free.

RXU to +.03.
--------------------------------------------------------------------------------
980204038 HUTCH PHYSICS_OPERATOR 4-FEB-1998 16:33:05.47
. . . . . . . . . . . . . . . . . . . .
Plasma. Mostly ELM-free, with little burps. Nicely elliptical.

Raise nl04 to 1.3
--------------------------------------------------------------------------------
980204039 HUTCH PHYSICS_OPERATOR 4-FEB-1998 16:45:01.56
. . . . . . . . . . . . . . . . . . . .
Plasma. Very long elm-free, but with little cleaning burps.

Load from shot 24.
Install ramps from low to high in RXU and RXL, .61 to1.15s.
nl04 to 1.3
--------------------------------------------------------------------------------
980204040 HUTCH PHYSICS_OPERATOR 4-FEB-1998 16:56:37.33
. . . . . . . . . . . . . . . . . . . .
lasma. Beautiful demonstration of the effect.
H-alpha ramps down as the triangularity does.

Try for a top-only scan.
Keep RXL fixed at zero. Scan RXU from -.07 to +.03,
--------------------------------------------------------------------------------
980204041 HUTCH PHYSICS_OPERATOR 4-FEB-1998 17:00:15.85
. . . . . . . . . . . . . . . . . . . .
Plasma. Stays in essentially steady EDA.
Off-hand this is an indication that the lower triangularity is
the strongest effect. We need more studies/analysis t

Entered: Jul 7 2004 04:36:58:990PM

Author: To Be Determined

tell
how strong the upper is.

Session Leader Comments

Feb 4 1998 08:33:11:440AM Martin Greenwald Run Plan for 980204
MP 143B

The general approach is to run a given equilibrium then scan the target
density/gas puff to find (if possible) the ELMfree/EDA boundary. Prf
will be fixed somewhere between 2 - 2.5 MW.

For equilibria,

1. start with our normal shape.

2. Keeping the lower triangularity fixed at 0.54, scan the upper
triangularity between its minimum and maximum (at least 0.2-0.6).

3. With the upper triangularity fixed at ?, scan the lower triangularity
from (around) 0.4 to 0.65

4. If time permits pursue most promising part of the remaining
operating space.

Feb 4 1998 08:41:19:460AM 980204001 Martin Greenwald Good Fiducial shot

Feb 4 1998 09:04:34:470AM 980204002 Martin Greenwald Good Shot

H-mode type: EDA

delta_l = .51
delta_u = .32
ne target = 1.7
nemax = 3.9
div n0 target= 20
div n0 max = 39
Wmhd = .145
Prad/Ptot = .54

Feb 4 1998 09:11:53:360AM 980204003 Martin Greenwald Disrupts at .74

Feb 4 1998 09:31:42:040AM 980204004 Martin Greenwald Good Shot

H-mode type: mix of EDA and type III ELMS

delta_l = .50
delta_u = .17
ne target = 1.7
nemax = 4.0
div n0 = 32
div n0 max = 35
prad/ptot = .6
Wmhd = .14

Feb 4 1998 09:44:26:600AM 980204005 Martin Greenwald Good Shot

H-mode type: marginally EDA, with Type III ELMS, brief ELMfree periods

delta_l = .5
delta_u = .17
ne target = 1.7
nemax = 4.0
div n0 = 30
div n0 max = 37
prad/ptot = 0.6
Wmhd = .136

Feb 4 1998 10:03:17:550AM 980204006 Martin Greenwald Good Shot

H-mode type: more or less steady EDA

delta_l = .51
delta_u = .16
ne target = 2.4
nemax = 4.0
div n0 = 60
div n0 max = 65
prad/ptot = .4 - .5
Wmhd = .117

Feb 4 1998 10:28:08:210AM 980204007 Martin Greenwald Good Shot

H-mode type: Two hmode periods, the first ELMfree/Dithering to EDA

delta_l = .50
delta_u = .16
ne target = 3.3
nemax = 4.2, 3.8
div n0 = 15
div n0 max = 51
prad/ptot = .6, .5
Wmhd = .115

Feb 4 1998 10:26:36:570AM 980204008 Martin Greenwald Good Shot

H-mode type: multiple EDA/EFree hmodes

delta_l = .50
delta_u =.17
ne target =1.48
nemax = 4.0
div n0 = 13
div n0 max = 30
prad/ptot = .6
Wmhd = .135

Feb 4 1998 10:37:21:110AM 980204009 Martin Greenwald
Good Shot

H-mode type: Multiple EF/EDA, ragged RF, strong impurity accumulation

delta_l = .50
delta_u = .15
ne target = 1.4
nemax = 3.6
div n0 = 10
div n0 max = 20
prad/ptot =
Wmhd = .144

Feb 4 1998 10:54:35:990AM 980204010 Martin Greenwald
Good Shot

H-mode type: 3 periods, first most EF-like, EDA-like Halpha on all

delta_l = .5
delta_u = .36
ne target = 1.4
nemax = 3.6
div n0 = 18
div n0 max = 18
prad/ptot = .7,.5,.45
Wmhd = .14

Feb 4 1998 11:04:07:910AM 980204011 Martin Greenwald
Good Shot

H-mode type: 2 periods, first more EF-like, with
stronger impurity accumulation on first

delta_l = .50
delta_u = .40
ne target = 1.4
nemax = 3.4
div n0 = 10
div n0 max = 15
prad/ptot = .7,.4
Wmhd = .15

Feb 4 1998 11:20:07:120AM 980204012 Martin Greenwald early disruption

Feb 4 1998 11:29:18:800AM 980204013 Martin Greenwald
Interesting Shot, but only 1 MW on RF
high density / marfe trips one transmitter

Feb 4 1998 11:38:33:330AM 980204014 Martin Greenwald Even higher density, stronger marfe
RF trips - only 1 MW

Feb 4 1998 11:55:25:510AM 980204015 Martin Greenwald
Good Shot

H-mode type: Long Steady EDA

delta_l = .5
delta_u = .4
ne target = 1.6
nemax = 3.6
div n0 = 30
div n0 max = 30
prad/ptot = .6 dropping to .4
Wmhd = .145

Feb 4 1998 12:11:09:690PM 980204016 Martin Greenwald Good Shot

H-mode type: Steady EDA

delta_l = .5
delta_u = .6
ne target = 1.7
nemax = 3.1
div n0 = 30
div n0 max = 20
prad/ptot = .4
Wmhd = .15

Feb 4 1998 12:25:29:630PM 980204017 Martin Greenwald Good Shot

H-mode type: Barely EDA, changing to steadier EDA

delta_l = .5
delta_u = .6
ne target = 1.5
nemax = 3.3
div n0 = 20
div n0 max = 10
prad/ptot = .6,.4
Wmhd = .15

Feb 4 1998 12:39:44:110PM 980204018 Martin Greenwald
Good Shot

H-mode type: Brief ELMfree period followed by long steadier EDA

delta_l = .5
delta_u = .6
ne target = 1.5
nemax = 3.4
div n0 = 10
div n0 max = 20
prad/ptot = .8,.6
Wmhd = .135

Feb 4 1998 12:54:29:660PM 980204019 Martin Greenwald
Good Shot

H-mode type: similar to 18, ELMfree period, radiation collapse, then EDA

delta_l = .5
delta_u = .6
ne target = 1.5
nemax = 3.1
div n0 = 12
div n0 max = 8
prad/ptot = .8,.5
Wmhd = .15

Feb 4 1998 01:03:27:370PM 980204020 Martin Greenwald
Good Shot

H-mode type: multiple H-modes mostly ELMfree

delta_l = .5
delta_u = .6
ne target = 1.35
nemax = 3.2
div n0 = 5
div n0 max = 10
prad/ptot = .8
Wmhd = .14

Feb 4 1998 01:18:24:490PM 980204021 Martin Greenwald
Good Shot

H-mode type: steady EDA

delta_l = .5
delta_u = .4
ne target = 1.4
nemax = 3.4
div n0 = 10
div n0 max = 5
prad/ptot = .4-.6
Wmhd = .15

Feb 4 1998 01:28:29:570PM 980204022 Martin Greenwald
Good Shot

H-mode type: Three Phases, ELMfree then mixed, then EDA

delta_l = .5
delta_u = .4
ne target = 1.1
nemax = 3.3
div n0 = 10
div n0 max = 5
prad/ptot = .8
Wmhd = .14

Feb 4 1998 01:41:45:910PM 980204023 Martin Greenwald Good Shot

H-mode type: 4 phases from ELMfree to marginally EDA

delta_l = .64
delta_u = .35
ne target = 1.3
nemax = 3.3
div n0 = 5
div n0 max = 10
prad/ptot = .6
Wmhd = .14

Feb 4 1998 01:58:19:670PM 980204024 Martin Greenwald
Good Shot

H-mode type: Steady EDA

delta_l = .63
delta_u = .36
ne target = 1.9
nemax = 3.3
div n0 = 25
div n0 max = 30
prad/ptot = .55
Wmhd = .125

Feb 4 1998 02:01:05:560PM 980204025 Martin Greenwald
Good Shot

But no RF, no H-modes

Feb 4 1998 02:33:48:190PM 980204026 Martin Greenwald No RF, but no data

Feb 4 1998 02:32:35:910PM 980204027 Martin Greenwald No RF - L-mode

Feb 4 1998 02:42:09:060PM 980204028 Martin Greenwald no RF - L-mode

Feb 4 1998 02:58:12:720PM 980204029 Martin Greenwald Short RF pulse only - test

Feb 4 1998 03:08:30:420PM 980204030 Martin Greenwald Good fiducial shot - RF tests out ok

Feb 4 1998 03:16:12:760PM 980204031 Martin Greenwald magnet resistance fault - no plasma

Feb 4 1998 03:24:30:750PM 980204032 Martin Greenwald very early program

Feb 4 1998 03:40:36:610PM 980204033 Martin Greenwald RF shows 2.5 MW but no H-mode

Feb 4 1998 03:47:32:980PM 980204034 Martin Greenwald OK Shot

H-mode type: Multiple ELMfree H-modes, RF trips

delta_l = .4
delta_u = .4

Feb 4 1998 04:02:24:660PM 980204035 Martin Greenwald
Good Shot

H-mode type: Multiple ELMfree

delta_l = .4
delta_u = .4
ne target = 1.3
nemax = 3.2
div n0 = 7
div n0 max = 10
prad/ptot = .8
Wmhd = .12

Feb 4 1998 04:08:18:310PM 980204036 Martin Greenwald Good Shot

H-mode type: Multiple ELMfree, Prf only 1.5 MW

delta_l = .4
delta_u = .4
ne target = 1.4
nemax = 3.2
div n0 = 7
div n0 max = 15
prad/ptot = .7
Wmhd = .11

Feb 4 1998 04:14:20:250PM 980204037 Martin Greenwald Interesting Shot

Full RF power again but no H-mode

delta_l = .4
delta_u = .4

Feb 4 1998 04:27:32:600PM 980204038 Martin Greenwald Good Shot

H-mode type: Multiple ELMfree

delta_l = .4
delta_u = .2
ne target = 1.8
nemax = 3.3
div n0 = 31
div n0 max = 40
prad/ptot = .8
Wmhd = .13

Feb 4 1998 04:39:27:000PM 980204039 Martin Greenwald
Good Shot

H-mode type: Multiple ELMfree

delta_l = .4
delta_u = .2
ne target = 1.9
nemax = 4.1
div n0 = 44
div n0 max = 53
prad/ptot = .65
Wmhd = .14

Feb 4 1998 04:51:21:980PM 980204040 Martin Greenwald Good Shot

H-mode type: EDA -> ELMfree in scan of both upper and
lower triangularities

delta_l = .6 -> .4
delta_u = .35 -> .18
ne target = 2.2
nemax = 4.2
div n0 = 60
div n0 max = 55
prad/ptot = .4 -> .6
Wmhd = .145

Feb 4 1998 05:05:05:070PM 980204041 Martin Greenwald Good Shot

H-mode type: Steady EDA
scan upper triangularity

delta_l = .52
delta_u = .47 -> .2
ne target = 2.0
nemax = 3.9
div n0 = 65
div n0 max = 60
prad/ptot = .4
Wmhd = .135

Physics Operator Comments

Feb 4 1998 08:33:39:030AM Ian Hutchinson Triangularity Scan 143B
Trying to see what effect shape has on the EDA effects.

Cold Start.
Load 980103006 oops. Mistake.
PCS brings my station to a freeze and then blows itself away!
Restart from DCL prompt.
Try to load 980203006.
OK.

Feb 4 1998 08:51:27:590AM 980204001 Ian Hutchinson Plasma. Fiducial.

Feb 4 1998 09:09:46:480AM 980204002 Ian Hutchinson Switch to segment 2.
Plasma. This is a strange shot left over from Wolfe.
Not recommended method of control because this had
strikepsi etc, But actually gives a nice long EDA mode.

Remove STrikepsi gain.
REturn zxl gain to 8 throughout.
Adjust rxl to be out earlier.

Feb 4 1998 09:23:32:160AM 980204003 Ian Hutchinson Plasma. Disrupts at .74s. Brick.
A bit too slot-like.

Copy TF from segment 2 to segment 1.
ZXL to 0 from -.017. Try to make less slotty.
RXU to .03 from -.02. Reduce the upper triangularity.
Copy TF from segment 4 to 2 and 1. Want 5.4T.

Feb 4 1998 09:36:50:530AM 980204004 Ian Hutchinson Plasma. Lots of little H-modes. Strange H-alpha behaviour.

Rcur to .668 from .669.

Feb 4 1998 09:48:05:060AM 980204005 Ian Hutchinson Plasma.

Target density to nl04=1.5,
rcur to .667.

Feb 4 1998 10:04:40:420AM 980204006 Ian Hutchinson Plasma. Nearly killed it in the current rise, but recovered.

EF4 to -1340 from -1345.
nl04 to 1.8.

Feb 4 1998 10:16:30:740AM 980204007 Ian Hutchinson Plasma. Fuelled quite effectively till RF turn-on.
Then 2 H-modes of different character.

Lower target density to .6.

Feb 4 1998 10:31:21:680AM 980204008 Ian Hutchinson Plasma. Lower density. Goy .85 target.
Multiple H-modes with impurity accumulation.

Call the zcur predictors.

Feb 4 1998 10:44:29:170AM 980204009 Ian Hutchinson Plasma. Some hards. Didn't get much lower density.
RF has some problems.

EF4 to -1335.
RXU to -.04.
Argon puff to 25ms from 35.

Feb 4 1998 10:57:23:300AM 980204010 Ian Hutchinson Plasma. Still hards.

EF4 to -1330.
Zcur to -.01 from .015.

Feb 4 1998 11:10:43:730AM 980204011 Ian Hutchinson Plasma.

Load nl04 wire 14 from shot 6. High density.

Feb 4 1998 11:20:15:610AM 980204012 Ian Hutchinson Plasma. Disrupts at .57s. Strange effect at .5s after soaking up
the gas quite nicely. Perhaps that is the poloidal detachment ending.
Then hit by a brick.

Feb 4 1998 11:35:14:620AM 980204013 Ian Hutchinson Plasma.

Lower nl04 a tad in the first .5s to reduce the detachment etc.

Feb 4 1998 11:46:58:250AM 980204014 Ian Hutchinson Plasma. Density is even higher.

Lower nl04 target to 1.

Feb 4 1998 12:13:33:960PM 980204016 Ian Hutchinson Plasma. Nicely sustained EDA.

RXU to -.07m to increase the upper triangularity some more.
IC_ef4 to 2000A.

plasma. Looks like one long EDA. Triangularity up to 0.6.

Next shot, drop nl4 to .7e20.

Feb 4 1998 12:26:52:520PM 980204017 Ian Hutchinson Shot 17: Drop nl4 to .7e20
(wolfe sitting in as physop)

plasma disrupts at 1.39 sec, pf breaker pulled. ef1l crowbarred at 1.28sec
Target gets to .9e20.
Wplasm is decaying, starts almost Elm-free, then EDA increases solwly.

Next shot, just repeat and see if density comes down some more.

Feb 4 1998 12:39:08:430PM 980204018 Ian Hutchinson Shot 18: repeat.
Note that we are puffing into the H-mode, since there is a 50V level on PG3 and the nl4 program
goes up to 1.7e20.

Target still at .9
ELM-free until .78sec, then EDA after the H-L/injection.

Next shot, Reduce PG3 voltage program from 50V to 30V after .425sec

Feb 4 1998 12:51:21:130PM 980204019 Ian Hutchinson Shot 19: Reduce PG3 voltage program from 50V to 30V after .425sec

Target density still not dropping
Starts ELM-free, then H=L with 2pi at 2MW, then comes back as EDA.

One more try at lowering the density.

Feb 4 1998 01:00:26:650PM 980204020 Ian Hutchinson Shot 20: Reduce PG3 voltage program from 30V to 0. after .425
Target density to .64 early (from .75)

3 h-modes, got the lower density this time.
Next shot, back to shot 11.

Feb 4 1998 01:15:24:560PM 980204021 Ian Hutchinson Shot 21: Import Segment 2 from shot 11 (and rename the segment)
Plasma. nl04 .8 target. EDA for .35s but with significant radiation.

Lower PG3 gas puff to 10 from 50V.

Feb 4 1998 01:38:21:510PM 980204022 Ian Hutchinson Plasma. True ELM-free phase to start with.

RXL to -.025m. Increase x-point triangularity.

Feb 4 1998 01:44:20:740PM 980204023 Ian Hutchinson Plasma. Got triangularity of .6. X-point just off the inner nose.
ELM-free with increasing H-alpha later, but all with radiation.

Raise nl04 to 1. Raise gas puff to 50V.

Feb 4 1998 01:56:02:230PM 980204024 Ian Hutchinson Plasma. Sustained EDA. Got 1.1 target. Still serious radiation.

nl04 to 1.6.

Feb 4 1998 02:07:13:160PM 980204025 Ian Hutchinson Plasma. No RF
Enormous amounts of gas injected. Slow density ramp.
No marfe after .3s.

Repeat.

Feb 4 1998 02:29:27:630PM 980204026 Ian Hutchinson Plasma. No RF again.
DAQA reboots itself. No data.

Lower the nl04.
RXL to +.02.

Feb 4 1998 02:38:18:510PM 980204027 Ian Hutchinson Plasma. Looks like I forgot to load. No RF.

Load.

Feb 4 1998 02:53:16:590PM 980204028 Ian Hutchinson Plasma. No RF.

RXU to -.05. G wants higher.
RXL to +.03m.

Feb 4 1998 03:06:32:200PM 980204029 Ian Hutchinson Plasma. RF seems able to coule at the end, but they report
strange loading.

Reenable fiducial segment.

Feb 4 1998 03:15:36:020PM 980204030 Ian Hutchinson Plasma. Seems ok for the RF.

Back to the triangularity shot.

Feb 4 1998 03:23:24:220PM 980204031 Ian Hutchinson Power supply dud. Magnet resistance fault.

Feb 4 1998 03:31:58:350PM 980204032 Ian Hutchinson Plasma lasts till 100ms. Seems like a brick.

Feb 4 1998 03:43:20:130PM 980204033 Ian Hutchinson Plasma. Got 2+MW, but no H-mode. Some heating. Low radiation.

Lower nl04 to .6, Gas puff to 10V.

Feb 4 1998 03:53:58:400PM 980204034 Ian Hutchinson Plasma. Multiple ELM-free H-modes. But the RF trips off.

Lower PG3 a tad at .25s.

Feb 4 1998 04:01:40:480PM 980204035 Ian Hutchinson Plasma. Multiple H-modes, ELM-Free. RF stays on better but still bad.

nl04 to .8.

Feb 4 1998 04:15:25:030PM 980204036 Ian Hutchinson Plasma. Multiple ELM-free H-modes.
RF 1.4MW.

nl04 to 1.1, puff V to 30V.

Feb 4 1998 04:22:21:710PM 980204037 Ian Hutchinson Plasma L-mode. Target 1e20!
Pretty clear that these low-xpoint-triangularity shots have a higher
H-mode trheshold power and tetnd to stay in ELM-free.

RXU to +.03.

Feb 4 1998 04:33:05:470PM 980204038 Ian Hutchinson Plasma. Mostly ELM-free, with little burps. Nicely elliptical.

Raise nl04 to 1.3

Feb 4 1998 04:45:01:560PM 980204039 Ian Hutchinson Plasma. Very long elm-free, but with little cleaning burps.

Load from shot 24.
Install ramps from low to high in RXU and RXL, .61 to1.15s.
nl04 to 1.3

Feb 4 1998 04:56:37:330PM 980204040 Ian Hutchinson lasma. Beautiful demonstration of the effect.
H-alpha ramps down as the triangularity does.

Try for a top-only scan.
Keep RXL fixed at zero. Scan RXU from -.07 to +.03,

Feb 4 1998 05:00:15:850PM 980204041 Ian Hutchinson Plasma. Stays in essentially steady EDA.
Off-hand this is an indication that the lower triangularity is
the strongest effect. We need more studies/analysis to tell
how strong the upper is.

Engineering Operator Comments

Shot Time Type Status Comment

1 08:35:54:580AM Plasma Ok

2 08:49:25:530AM Plasma Ok

3 09:07:48:010AM Plasma Ok

4 09:21:54:460AM Plasma Ok

5 09:35:00:680AM Plasma Ok

6 09:46:04:940AM Plasma Bad ef1 upper comm fault first

7 10:02:02:200AM Plasma Ok

8 10:15:17:550AM Plasma Ok

9 10:29:20:730AM Plasma Ok

10 10:42:59:890AM Plasma Ok

11 10:56:09:640AM Plasma Ok

12 11:10:45:810AM Plasma Ok

13 11:21:47:830AM Plasma Ok

14 11:35:27:830AM Plasma Ok

15 11:48:10:580AM Plasma Ok

16 12:01:58:720PM Plasma Ok

17 12:17:13:860PM Plasma Bad ef1l comm fault

18 12:32:56:830PM Plasma Ok

19 12:45:04:800PM Plasma Ok

20 12:56:16:420PM Plasma Ok

21 01:08:26:850PM Plasma Ok no faults plasma

22 01:18:35:660PM Plasma Ok no faults/plasma

23 01:31:54:340PM Plasma Ok no faults/plasma

24 01:42:56:060PM Plasma Ok no faults/plasma

25 01:53:53:180PM Plasma Ok no faults/plasma

26 02:05:12:650PM Plasma Ok no mfaults/plasma

27 02:26:33:750PM Plasma Ok no faults/plasma

28 02:36:29:460PM Plasma Ok no faults/plasma

29 02:50:57:130PM Plasma Ok no faults/plasma

30 03:04:56:070PM Plasma Ok no faults/plasma

31 03:13:54:880PM Plasma Bad mag res fault no pulse

32 03:21:40:780PM Plasma Ok no faults

33 03:30:33:540PM Plasma Ok no faults/plasma

34 03:41:54:440PM Plasma Ok no faults/plasma

35 03:51:34:660PM Plasma Ok no faults/plasma

36 03:59:42:100PM Plasma Ok no faults

37 04:09:22:420PM Plasma Ok no faults/plasma

38 04:19:45:530PM Plasma Ok no faults/plasma

39 04:31:26:620PM Plasma Ok nofaults/plasma

40 04:43:21:690PM Plasma Ok no faults, good plasma

41 04:54:35:830PM Plasma Ok no faults/plasma

Session Leader Comments
Feb 4 1998 08:33:11:440AM		Martin Greenwald	Run Plan for 980204 MP 143B The general approach is to run a given equilibrium then scan the target density/gas puff to find (if possible) the ELMfree/EDA boundary. Prf will be fixed somewhere between 2 - 2.5 MW. For equilibria, 1. start with our normal shape. 2. Keeping the lower triangularity fixed at 0.54, scan the upper triangularity between its minimum and maximum (at least 0.2-0.6). 3. With the upper triangularity fixed at ?, scan the lower triangularity from (around) 0.4 to 0.65 4. If time permits pursue most promising part of the remaining operating space.
Feb 4 1998 08:41:19:460AM	980204001	Martin Greenwald	Good Fiducial shot
Feb 4 1998 09:04:34:470AM	980204002	Martin Greenwald	Good Shot H-mode type: EDA delta_l = .51 delta_u = .32 ne target = 1.7 nemax = 3.9 div n0 target= 20 div n0 max = 39 Wmhd = .145 Prad/Ptot = .54
Feb 4 1998 09:11:53:360AM	980204003	Martin Greenwald	Disrupts at .74
Feb 4 1998 09:31:42:040AM	980204004	Martin Greenwald	Good Shot H-mode type: mix of EDA and type III ELMS delta_l = .50 delta_u = .17 ne target = 1.7 nemax = 4.0 div n0 = 32 div n0 max = 35 prad/ptot = .6 Wmhd = .14
Feb 4 1998 09:44:26:600AM	980204005	Martin Greenwald	Good Shot H-mode type: marginally EDA, with Type III ELMS, brief ELMfree periods delta_l = .5 delta_u = .17 ne target = 1.7 nemax = 4.0 div n0 = 30 div n0 max = 37 prad/ptot = 0.6 Wmhd = .136
Feb 4 1998 10:03:17:550AM	980204006	Martin Greenwald	Good Shot H-mode type: more or less steady EDA delta_l = .51 delta_u = .16 ne target = 2.4 nemax = 4.0 div n0 = 60 div n0 max = 65 prad/ptot = .4 - .5 Wmhd = .117
Feb 4 1998 10:28:08:210AM	980204007	Martin Greenwald	Good Shot H-mode type: Two hmode periods, the first ELMfree/Dithering to EDA delta_l = .50 delta_u = .16 ne target = 3.3 nemax = 4.2, 3.8 div n0 = 15 div n0 max = 51 prad/ptot = .6, .5 Wmhd = .115
Feb 4 1998 10:26:36:570AM	980204008	Martin Greenwald	Good Shot H-mode type: multiple EDA/EFree hmodes delta_l = .50 delta_u =.17 ne target =1.48 nemax = 4.0 div n0 = 13 div n0 max = 30 prad/ptot = .6 Wmhd = .135
Feb 4 1998 10:37:21:110AM	980204009	Martin Greenwald	Good Shot H-mode type: Multiple EF/EDA, ragged RF, strong impurity accumulation delta_l = .50 delta_u = .15 ne target = 1.4 nemax = 3.6 div n0 = 10 div n0 max = 20 prad/ptot = Wmhd = .144
Feb 4 1998 10:54:35:990AM	980204010	Martin Greenwald	Good Shot H-mode type: 3 periods, first most EF-like, EDA-like Halpha on all delta_l = .5 delta_u = .36 ne target = 1.4 nemax = 3.6 div n0 = 18 div n0 max = 18 prad/ptot = .7,.5,.45 Wmhd = .14
Feb 4 1998 11:04:07:910AM	980204011	Martin Greenwald	Good Shot H-mode type: 2 periods, first more EF-like, with stronger impurity accumulation on first delta_l = .50 delta_u = .40 ne target = 1.4 nemax = 3.4 div n0 = 10 div n0 max = 15 prad/ptot = .7,.4 Wmhd = .15
Feb 4 1998 11:20:07:120AM	980204012	Martin Greenwald	early disruption
Feb 4 1998 11:29:18:800AM	980204013	Martin Greenwald	Interesting Shot, but only 1 MW on RF high density / marfe trips one transmitter
Feb 4 1998 11:38:33:330AM	980204014	Martin Greenwald	Even higher density, stronger marfe RF trips - only 1 MW
Feb 4 1998 11:55:25:510AM	980204015	Martin Greenwald	Good Shot H-mode type: Long Steady EDA delta_l = .5 delta_u = .4 ne target = 1.6 nemax = 3.6 div n0 = 30 div n0 max = 30 prad/ptot = .6 dropping to .4 Wmhd = .145
Feb 4 1998 12:11:09:690PM	980204016	Martin Greenwald	Good Shot H-mode type: Steady EDA delta_l = .5 delta_u = .6 ne target = 1.7 nemax = 3.1 div n0 = 30 div n0 max = 20 prad/ptot = .4 Wmhd = .15
Feb 4 1998 12:25:29:630PM	980204017	Martin Greenwald	Good Shot H-mode type: Barely EDA, changing to steadier EDA delta_l = .5 delta_u = .6 ne target = 1.5 nemax = 3.3 div n0 = 20 div n0 max = 10 prad/ptot = .6,.4 Wmhd = .15
Feb 4 1998 12:39:44:110PM	980204018	Martin Greenwald	Good Shot H-mode type: Brief ELMfree period followed by long steadier EDA delta_l = .5 delta_u = .6 ne target = 1.5 nemax = 3.4 div n0 = 10 div n0 max = 20 prad/ptot = .8,.6 Wmhd = .135
Feb 4 1998 12:54:29:660PM	980204019	Martin Greenwald	Good Shot H-mode type: similar to 18, ELMfree period, radiation collapse, then EDA delta_l = .5 delta_u = .6 ne target = 1.5 nemax = 3.1 div n0 = 12 div n0 max = 8 prad/ptot = .8,.5 Wmhd = .15
Feb 4 1998 01:03:27:370PM	980204020	Martin Greenwald	Good Shot H-mode type: multiple H-modes mostly ELMfree delta_l = .5 delta_u = .6 ne target = 1.35 nemax = 3.2 div n0 = 5 div n0 max = 10 prad/ptot = .8 Wmhd = .14
Feb 4 1998 01:18:24:490PM	980204021	Martin Greenwald	Good Shot H-mode type: steady EDA delta_l = .5 delta_u = .4 ne target = 1.4 nemax = 3.4 div n0 = 10 div n0 max = 5 prad/ptot = .4-.6 Wmhd = .15
Feb 4 1998 01:28:29:570PM	980204022	Martin Greenwald	Good Shot H-mode type: Three Phases, ELMfree then mixed, then EDA delta_l = .5 delta_u = .4 ne target = 1.1 nemax = 3.3 div n0 = 10 div n0 max = 5 prad/ptot = .8 Wmhd = .14
Feb 4 1998 01:41:45:910PM	980204023	Martin Greenwald	Good Shot H-mode type: 4 phases from ELMfree to marginally EDA delta_l = .64 delta_u = .35 ne target = 1.3 nemax = 3.3 div n0 = 5 div n0 max = 10 prad/ptot = .6 Wmhd = .14
Feb 4 1998 01:58:19:670PM	980204024	Martin Greenwald	Good Shot H-mode type: Steady EDA delta_l = .63 delta_u = .36 ne target = 1.9 nemax = 3.3 div n0 = 25 div n0 max = 30 prad/ptot = .55 Wmhd = .125
Feb 4 1998 02:01:05:560PM	980204025	Martin Greenwald	Good Shot But no RF, no H-modes
Feb 4 1998 02:33:48:190PM	980204026	Martin Greenwald	No RF, but no data
Feb 4 1998 02:32:35:910PM	980204027	Martin Greenwald	No RF - L-mode
Feb 4 1998 02:42:09:060PM	980204028	Martin Greenwald	no RF - L-mode
Feb 4 1998 02:58:12:720PM	980204029	Martin Greenwald	Short RF pulse only - test
Feb 4 1998 03:08:30:420PM	980204030	Martin Greenwald	Good fiducial shot - RF tests out ok
Feb 4 1998 03:16:12:760PM	980204031	Martin Greenwald	magnet resistance fault - no plasma
Feb 4 1998 03:24:30:750PM	980204032	Martin Greenwald	very early program
Feb 4 1998 03:40:36:610PM	980204033	Martin Greenwald	RF shows 2.5 MW but no H-mode
Feb 4 1998 03:47:32:980PM	980204034	Martin Greenwald	OK Shot H-mode type: Multiple ELMfree H-modes, RF trips delta_l = .4 delta_u = .4
Feb 4 1998 04:02:24:660PM	980204035	Martin Greenwald	Good Shot H-mode type: Multiple ELMfree delta_l = .4 delta_u = .4 ne target = 1.3 nemax = 3.2 div n0 = 7 div n0 max = 10 prad/ptot = .8 Wmhd = .12
Feb 4 1998 04:08:18:310PM	980204036	Martin Greenwald	Good Shot H-mode type: Multiple ELMfree, Prf only 1.5 MW delta_l = .4 delta_u = .4 ne target = 1.4 nemax = 3.2 div n0 = 7 div n0 max = 15 prad/ptot = .7 Wmhd = .11
Feb 4 1998 04:14:20:250PM	980204037	Martin Greenwald	Interesting Shot Full RF power again but no H-mode delta_l = .4 delta_u = .4
Feb 4 1998 04:27:32:600PM	980204038	Martin Greenwald	Good Shot H-mode type: Multiple ELMfree delta_l = .4 delta_u = .2 ne target = 1.8 nemax = 3.3 div n0 = 31 div n0 max = 40 prad/ptot = .8 Wmhd = .13
Feb 4 1998 04:39:27:000PM	980204039	Martin Greenwald	Good Shot H-mode type: Multiple ELMfree delta_l = .4 delta_u = .2 ne target = 1.9 nemax = 4.1 div n0 = 44 div n0 max = 53 prad/ptot = .65 Wmhd = .14
Feb 4 1998 04:51:21:980PM	980204040	Martin Greenwald	Good Shot H-mode type: EDA -> ELMfree in scan of both upper and lower triangularities delta_l = .6 -> .4 delta_u = .35 -> .18 ne target = 2.2 nemax = 4.2 div n0 = 60 div n0 max = 55 prad/ptot = .4 -> .6 Wmhd = .145
Feb 4 1998 05:05:05:070PM	980204041	Martin Greenwald	Good Shot H-mode type: Steady EDA scan upper triangularity delta_l = .52 delta_u = .47 -> .2 ne target = 2.0 nemax = 3.9 div n0 = 65 div n0 max = 60 prad/ptot = .4 Wmhd = .135

Physics Operator Comments
Feb 4 1998 08:33:39:030AM		Ian Hutchinson	Triangularity Scan 143B Trying to see what effect shape has on the EDA effects. Cold Start. Load 980103006 oops. Mistake. PCS brings my station to a freeze and then blows itself away! Restart from DCL prompt. Try to load 980203006. OK.
Feb 4 1998 08:51:27:590AM	980204001	Ian Hutchinson	Plasma. Fiducial.
Feb 4 1998 09:09:46:480AM	980204002	Ian Hutchinson	Switch to segment 2. Plasma. This is a strange shot left over from Wolfe. Not recommended method of control because this had strikepsi etc, But actually gives a nice long EDA mode. Remove STrikepsi gain. REturn zxl gain to 8 throughout. Adjust rxl to be out earlier.
Feb 4 1998 09:23:32:160AM	980204003	Ian Hutchinson	Plasma. Disrupts at .74s. Brick. A bit too slot-like. Copy TF from segment 2 to segment 1. ZXL to 0 from -.017. Try to make less slotty. RXU to .03 from -.02. Reduce the upper triangularity. Copy TF from segment 4 to 2 and 1. Want 5.4T.
Feb 4 1998 09:36:50:530AM	980204004	Ian Hutchinson	Plasma. Lots of little H-modes. Strange H-alpha behaviour. Rcur to .668 from .669.
Feb 4 1998 09:48:05:060AM	980204005	Ian Hutchinson	Plasma. Target density to nl04=1.5, rcur to .667.
Feb 4 1998 10:04:40:420AM	980204006	Ian Hutchinson	Plasma. Nearly killed it in the current rise, but recovered. EF4 to -1340 from -1345. nl04 to 1.8.
Feb 4 1998 10:16:30:740AM	980204007	Ian Hutchinson	Plasma. Fuelled quite effectively till RF turn-on. Then 2 H-modes of different character. Lower target density to .6.
Feb 4 1998 10:31:21:680AM	980204008	Ian Hutchinson	Plasma. Lower density. Goy .85 target. Multiple H-modes with impurity accumulation. Call the zcur predictors.
Feb 4 1998 10:44:29:170AM	980204009	Ian Hutchinson	Plasma. Some hards. Didn't get much lower density. RF has some problems. EF4 to -1335. RXU to -.04. Argon puff to 25ms from 35.
Feb 4 1998 10:57:23:300AM	980204010	Ian Hutchinson	Plasma. Still hards. EF4 to -1330. Zcur to -.01 from .015.
Feb 4 1998 11:10:43:730AM	980204011	Ian Hutchinson	Plasma. Load nl04 wire 14 from shot 6. High density.
Feb 4 1998 11:20:15:610AM	980204012	Ian Hutchinson	Plasma. Disrupts at .57s. Strange effect at .5s after soaking up the gas quite nicely. Perhaps that is the poloidal detachment ending. Then hit by a brick.
Feb 4 1998 11:35:14:620AM	980204013	Ian Hutchinson	Plasma. Lower nl04 a tad in the first .5s to reduce the detachment etc.
Feb 4 1998 11:46:58:250AM	980204014	Ian Hutchinson	Plasma. Density is even higher. Lower nl04 target to 1.
Feb 4 1998 12:13:33:960PM	980204016	Ian Hutchinson	Plasma. Nicely sustained EDA. RXU to -.07m to increase the upper triangularity some more. IC_ef4 to 2000A. plasma. Looks like one long EDA. Triangularity up to 0.6. Next shot, drop nl4 to .7e20.
Feb 4 1998 12:26:52:520PM	980204017	Ian Hutchinson	Shot 17: Drop nl4 to .7e20 (wolfe sitting in as physop) plasma disrupts at 1.39 sec, pf breaker pulled. ef1l crowbarred at 1.28sec Target gets to .9e20. Wplasm is decaying, starts almost Elm-free, then EDA increases solwly. Next shot, just repeat and see if density comes down some more.
Feb 4 1998 12:39:08:430PM	980204018	Ian Hutchinson	Shot 18: repeat. Note that we are puffing into the H-mode, since there is a 50V level on PG3 and the nl4 program goes up to 1.7e20. Target still at .9 ELM-free until .78sec, then EDA after the H-L/injection. Next shot, Reduce PG3 voltage program from 50V to 30V after .425sec
Feb 4 1998 12:51:21:130PM	980204019	Ian Hutchinson	Shot 19: Reduce PG3 voltage program from 50V to 30V after .425sec Target density still not dropping Starts ELM-free, then H=L with 2pi at 2MW, then comes back as EDA. One more try at lowering the density.
Feb 4 1998 01:00:26:650PM	980204020	Ian Hutchinson	Shot 20: Reduce PG3 voltage program from 30V to 0. after .425 Target density to .64 early (from .75) 3 h-modes, got the lower density this time. Next shot, back to shot 11.
Feb 4 1998 01:15:24:560PM	980204021	Ian Hutchinson	Shot 21: Import Segment 2 from shot 11 (and rename the segment) Plasma. nl04 .8 target. EDA for .35s but with significant radiation. Lower PG3 gas puff to 10 from 50V.
Feb 4 1998 01:38:21:510PM	980204022	Ian Hutchinson	Plasma. True ELM-free phase to start with. RXL to -.025m. Increase x-point triangularity.
Feb 4 1998 01:44:20:740PM	980204023	Ian Hutchinson	Plasma. Got triangularity of .6. X-point just off the inner nose. ELM-free with increasing H-alpha later, but all with radiation. Raise nl04 to 1. Raise gas puff to 50V.
Feb 4 1998 01:56:02:230PM	980204024	Ian Hutchinson	Plasma. Sustained EDA. Got 1.1 target. Still serious radiation. nl04 to 1.6.
Feb 4 1998 02:07:13:160PM	980204025	Ian Hutchinson	Plasma. No RF Enormous amounts of gas injected. Slow density ramp. No marfe after .3s. Repeat.
Feb 4 1998 02:29:27:630PM	980204026	Ian Hutchinson	Plasma. No RF again. DAQA reboots itself. No data. Lower the nl04. RXL to +.02.
Feb 4 1998 02:38:18:510PM	980204027	Ian Hutchinson	Plasma. Looks like I forgot to load. No RF. Load.
Feb 4 1998 02:53:16:590PM	980204028	Ian Hutchinson	Plasma. No RF. RXU to -.05. G wants higher. RXL to +.03m.
Feb 4 1998 03:06:32:200PM	980204029	Ian Hutchinson	Plasma. RF seems able to coule at the end, but they report strange loading. Reenable fiducial segment.
Feb 4 1998 03:15:36:020PM	980204030	Ian Hutchinson	Plasma. Seems ok for the RF. Back to the triangularity shot.
Feb 4 1998 03:23:24:220PM	980204031	Ian Hutchinson	Power supply dud. Magnet resistance fault.
Feb 4 1998 03:31:58:350PM	980204032	Ian Hutchinson	Plasma lasts till 100ms. Seems like a brick.
Feb 4 1998 03:43:20:130PM	980204033	Ian Hutchinson	Plasma. Got 2+MW, but no H-mode. Some heating. Low radiation. Lower nl04 to .6, Gas puff to 10V.
Feb 4 1998 03:53:58:400PM	980204034	Ian Hutchinson	Plasma. Multiple ELM-free H-modes. But the RF trips off. Lower PG3 a tad at .25s.
Feb 4 1998 04:01:40:480PM	980204035	Ian Hutchinson	Plasma. Multiple H-modes, ELM-Free. RF stays on better but still bad. nl04 to .8.
Feb 4 1998 04:15:25:030PM	980204036	Ian Hutchinson	Plasma. Multiple ELM-free H-modes. RF 1.4MW. nl04 to 1.1, puff V to 30V.
Feb 4 1998 04:22:21:710PM	980204037	Ian Hutchinson	Plasma L-mode. Target 1e20! Pretty clear that these low-xpoint-triangularity shots have a higher H-mode trheshold power and tetnd to stay in ELM-free. RXU to +.03.
Feb 4 1998 04:33:05:470PM	980204038	Ian Hutchinson	Plasma. Mostly ELM-free, with little burps. Nicely elliptical. Raise nl04 to 1.3
Feb 4 1998 04:45:01:560PM	980204039	Ian Hutchinson	Plasma. Very long elm-free, but with little cleaning burps. Load from shot 24. Install ramps from low to high in RXU and RXL, .61 to1.15s. nl04 to 1.3
Feb 4 1998 04:56:37:330PM	980204040	Ian Hutchinson	lasma. Beautiful demonstration of the effect. H-alpha ramps down as the triangularity does. Try for a top-only scan. Keep RXL fixed at zero. Scan RXU from -.07 to +.03,
Feb 4 1998 05:00:15:850PM	980204041	Ian Hutchinson	Plasma. Stays in essentially steady EDA. Off-hand this is an indication that the lower triangularity is the strongest effect. We need more studies/analysis to tell how strong the upper is.

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	08:35:54:580AM	Plasma	Ok
2	08:49:25:530AM	Plasma	Ok
3	09:07:48:010AM	Plasma	Ok
4	09:21:54:460AM	Plasma	Ok
5	09:35:00:680AM	Plasma	Ok
6	09:46:04:940AM	Plasma	Bad	ef1 upper comm fault first
7	10:02:02:200AM	Plasma	Ok
8	10:15:17:550AM	Plasma	Ok
9	10:29:20:730AM	Plasma	Ok
10	10:42:59:890AM	Plasma	Ok
11	10:56:09:640AM	Plasma	Ok
12	11:10:45:810AM	Plasma	Ok
13	11:21:47:830AM	Plasma	Ok
14	11:35:27:830AM	Plasma	Ok
15	11:48:10:580AM	Plasma	Ok
16	12:01:58:720PM	Plasma	Ok
17	12:17:13:860PM	Plasma	Bad	ef1l comm fault
18	12:32:56:830PM	Plasma	Ok
19	12:45:04:800PM	Plasma	Ok
20	12:56:16:420PM	Plasma	Ok
21	01:08:26:850PM	Plasma	Ok	no faults plasma
22	01:18:35:660PM	Plasma	Ok	no faults/plasma
23	01:31:54:340PM	Plasma	Ok	no faults/plasma
24	01:42:56:060PM	Plasma	Ok	no faults/plasma
25	01:53:53:180PM	Plasma	Ok	no faults/plasma
26	02:05:12:650PM	Plasma	Ok	no mfaults/plasma
27	02:26:33:750PM	Plasma	Ok	no faults/plasma
28	02:36:29:460PM	Plasma	Ok	no faults/plasma
29	02:50:57:130PM	Plasma	Ok	no faults/plasma
30	03:04:56:070PM	Plasma	Ok	no faults/plasma
31	03:13:54:880PM	Plasma	Bad	mag res fault no pulse
32	03:21:40:780PM	Plasma	Ok	no faults
33	03:30:33:540PM	Plasma	Ok	no faults/plasma
34	03:41:54:440PM	Plasma	Ok	no faults/plasma
35	03:51:34:660PM	Plasma	Ok	no faults/plasma
36	03:59:42:100PM	Plasma	Ok	no faults
37	04:09:22:420PM	Plasma	Ok	no faults/plasma
38	04:19:45:530PM	Plasma	Ok	no faults/plasma
39	04:31:26:620PM	Plasma	Ok	nofaults/plasma
40	04:43:21:690PM	Plasma	Ok	no faults, good plasma
41	04:54:35:830PM	Plasma	Ok	no faults/plasma