Alcator C-Mod Run 980113 Information

Miniproposals

Miniproposal: 154

Date Filed: 7/26/1996

Title: H modes in Helium Plasmas

First Author: Rejean Boivin

Session Leader: Rejean Boivin (shots 1-40)

Operators
Session leader(s):	Rejean Boivin
Physics operator(s):	Ian Hutchinson
Engineering operator(s):	Unknown

Engineering Operator Run Comment
MP154/Helium H Modes

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Entered: Jul 7 2004 03:49:17:790PM

Author: To Be Determined

MP 154
Helium H modes

Run Plan

ECDC in helium as much as possible to remove deuterium from
walls.

1) Tuesday OH test shot

2) Establish helium plasma
Use shot from 951215 run. (other helium run)
If old shot is more trouble than it's worth, take
980107025 with an outer gap of 1cm no more. Helium fill.
Start at density of nel~1x10^20.
Tweak amount of Hydrogen if needed for breakdown.
RF to reliable maximum power in 3-4 steps (100 msec each)
1-2 steps down if possible for hysteresis.
A slow ramp starting at 1 or 2 MW is also a possibility
Flattop til 1.1 sec.

3) If successful, scan density, lower at first, higher after
nel~ 0.7
0.4 (lower?)
0.5
0.9
1.4
1.8
2.2
and some in between if any interesting change is observed.
Amanda could also use a TF ramp or 2 for pedestal information.
(couple of shots)
Bruce L. would also like to try a high density detachment
without RF (1-2 shots).

4) Scan deuterium content by increasing deuterium
concentration from 0% to 100% by 10ish% increment.
Number of shots will depend on actual concentration
due to wall loading.

Diagnostics (e.g. spectroscopy) should be set for looking at
helium, especially for rotation/flow measurements.

We got a few plasmas breaking down in Helium but the
success rate was diminishing, so it is advisable to stay
in deuterium for breakdown until someone has lots of time
to learn to do it in Helium properly.

Well, it looks that in general, helium is BAD.
Although the machine feels unboronized, the helium
seems to generate a lot of Moly, increase the
threshold temperature to enter H mode, and make
them short, with MHD terminating them (so I was told).
The low density limit appeared seemingly earlier (
i.e. at higher density) than in deuterium. And in higher
density we didn't get H modes probably running out of power.
RF loading was low all day today (except towards the end
with more deuterium), indicating that the SOL was
shorter and that it was difficult to couple the RF
(for the same voltage). Diminishing the gap could have helped
but likely would have increase the Moly levels too.

Radiation was not that high, partly because the difference
between the 2pi and the bolos was much reduced in Helium,
and increasing again with more deuterium. The foremost
explanation would be that we remove the CX power losses
in Helium and got them back with more deuterium. The rest
was probably due to Moly.

After having ratty H modes, we increased the amount of deuterium
and got on the last shot something close to an EDA! An
interesting result after beating on the walls/antenna with
harsh helium.

So maybe neutrals are our friends!

Shot run down:

001 OH test shot

002 DUD

003 Fizzle, breakdown in Helium.

004 Fizzle

005 Fizzle

006 Fizzle

007 Plasma,
No H mode, lots of power, going where?
2pi slightly larger than Bolos!!!
No sawteeth, but modulations of radiated power near the edge.
High density though.

008 Fizzle

009 Fizzle

010 Fizzle

011 Fizzle

012 Plasma,
Got 3 small H modes
Very high density still,
Sawteeth are back

013 Plasma,
Got 8 small H modes
Lower density

014 Dud,

015 Fizzle

016 Good plasma,
6 small H modes plus an injection at 0.75 sec.

017 Plasma,
Disrupted after a good size (Boston) brick
fell in.

018 Fizzle

019 Fizzle

020 Fizzle

021 Fizzle

022 Fizzle

023 Fizzle

024 Move to deuterium breakdown
Plasma, runaways, brick at 0.47

025 Dud

026 Good 6 small H modes

027 Lower density, puffed hydrogen
plasma

028 Lowered density no H mode (or just barely kissing the threshold)

029 Repeat with more power, barely went into H mode.

030 Back to higher density, D alpha is pretty high

031 Plasma, high density, but no H mode

032 Plasma, try a TF ramp for ECE pedestal measurement
too high density, missed the H mode

033 Dud

034 Repeat, slightly lower density, got a better ramp for Amanda.

035 Repeat, better ramp for Amanda

036 Start putting deuterium in discharge

037 More deuterium (starting the see a small difference)

038 More deuterium (A bit more, neutron slightly up)

039 Even more deuterium, starting to see more differences

040 A lot more deuterium, maybe close to 50-50.

Physics Operator Summaries

Entered: Jul 7 2004 04:36:58:567PM

Author: To Be Determined

Physop Summary 980113. MP 154 Helium H-modes.
_____________________________________________

PO Hutch
SL Boivin

Overview
________

Completed essentially all of the plan.
1. Got initiation in pure He. But abandoned after a while because no
time to make robust.
2. Got He H-modes. But they tended to be nasty, brutish and short.
3. Did a density scan down as far as what seems to be the low density
limit and up to about 2e20 nl.
4. Did a gradual (4 shots) increase of the amount of D2 in the
discharge. The end of this scan, with substantial deuterium,
showed much different behavior.

Physop Stuff
____________

Plasmas initiated in Helium were obtained but not robustly. Shots
12-17 were, in effect, 4 out of 5 plasmas with He breakdown. (Although
14 was a PS dud caused by tf trip). However, after the
disruption on 17, current rise could not be restored, despite the
attainment of 45kA. Reliable He breakdown operation clearly needs more
development. Subsequent plasmas initiated in deuterium fill seemed to
give robust rises but had a problem of early runaways presumably owing
to the lack of prompt deuterium wall fuelling.

RF heating was found to be rather inefficient in the early part of the
run. The suspicion of low hydrogen level was confirmed qualitatively
by Weaver, who estimated 1/10 of the hydrogen level of last
week. Therefore a hydrogen puff was instituted using 2psi 20ms, PG5.
This seems to be much less hydrogen than the deuterium that comes from
the RF. Eventually it was raised to 80ms of 2 psi, but still seems to
be barely noticeable. We really need consistent reliable quantitative,
or at least relative measurements of the species fractions if we are
going to do serious science in this area.

The He H-modes were showing a very substantial radial position motion
inwards. This may have been responsible in part for the loading
problems that caused the RF to trip. It would be good to understand
the cause.

Scorecard
_________

Shot,Duration(s),Ipmax(MA) Shot,Duration(s),Ipmax
1 0.000 0.018 2 0.000 0.022
3 0.000 0.032 4 0.000 0.027
5 0.000 0.032 6 0.000 0.032
7 1.421 1.004 8 0.000 0.037
9 0.000 0.037 10 0.000 0.032
11 0.000 0.037 12 1.528 1.029
13 1.586 1.050 14 0.000 0.016
15 0.000 0.037 16 1.590 1.045
17 0.497 1.029 18 0.000 0.037
19 0.000 0.037 20 0.000 0.037
21 0.000 0.037 22 0.000 0.032
23 0.000 0.037 24 1.542 1.024
25 0.000 0.018 26 1.585 1.050
27 1.337 1.045 28 1.165 1.086
29 1.015 1.112 30 1.542 1.029
31 1.380 1.014 32 1.559 1.019
33 0.000 0.026 34 1.568 1.030
35 1.590 1.035 36 0.000 0.042
37 1.584 1.029 38 1.578 1.029
39 1.575 1.029 40 1.566 1.024

Finished summary for 980113 Total of 40 shots.
40 shots. 19 plasmas. 16 fizzles. 5 power-supply duds.

Details from Log-Book.
______________________

------------------------------------------------------------------------------
980113xxx HUTCH PHYSICS_OPERATOR 13-JAN-1998 08:28:38.78
. . . . . . . . . . . . . . . . . . . .
13 Jan 98 MP 154 H-modes in Helium plasmas.

Starting with Helium initiation attempts.
Gases available.
SG1 Hydrogen
SG2 D2
SG3 Helium-4
SG4 Argon
SG5 Nitrogen
SG6 Helium-3

Did cold start.
Gas: B-top He 6.2psi
K-side He 30 psi.
Fill pulse to 20 ms.
------------------------------------------------------------------------------
980113xxx HUTCH PHYSICS_OPERATOR 13-JAN-1998 08:54:07.96
. . . . . . . . . . . . . . . . . . . .
Load from
980107025
Gas pulse to 20 from 15ms.
Note, we had many hours of He ECDC over the weekend in preparation
for this run.
------------------------------------------------------------------------------
980113001 HUTCH PHYSICS_OPERATOR 13-JAN-1998 09:05:59.52
. . . . . . . . . . . . . . . . . . . .
OH test. OH2U shows the usual oscillations even during this test under PLC
control.
------------------------------------------------------------------------------
980113002 HUTCH PHYSICS_OPERATOR 13-JAN-1998 09:12:32.33
. . . . . . . . . . . . . . . . . . . .
Power supply dud. EF3 not switched on.
------------------------------------------------------------------------------
980113002 HUTCH PHYSICS_OPERATOR 13-JAN-1998 09:17:28.36
. . . . . . . . . . . . . . . . . . . .
Pressure on the ratiomatic reads .026 mtorr. It is stated that this should be
multiplied by a factor of 2. So the real pressure is about .05 mtorr.

------------------------------------------------------------------------------
980113003 HUTCH PHYSICS_OPERATOR 13-JAN-1998 09:33:03.84
. . . . . . . . . . . . . . . . . . . .
Breakdown at 5ms and rapid initial Ip rise to 35kA at 9ms, but then fizzles.
Bz is probably rising too slowly for the rate of current rise.
D_alpha trace peaks at 0.06 versus 0.12 for the D shot. This is
surprisingly high.

Fill puff to 30 ms.
------------------------------------------------------------------------------
980113004 HUTCH PHYSICS_OPERATOR 13-JAN-1998 09:41:43.09
. . . . . . . . . . . . . . . . . . . .
Fizzle. Breakdown. Current rise still extremely fast.
D_a drops to .045, Ratiomatic .04 mtorr.

EF3 voltage to 3000V at 4-9ms.
------------------------------------------------------------------------------
980113005 HUTCH PHYSICS_OPERATOR 13-JAN-1998 09:50:08.28
. . . . . . . . . . . . . . . . . . . .
Fizzle. Not changed very much but the B_z rise quicker.

EF4 to -1335 from -1345.
EF3 to 3000V at 3ms.
------------------------------------------------------------------------------
980113006 HUTCH PHYSICS_OPERATOR 13-JAN-1998 10:01:31.16
. . . . . . . . . . . . . . . . . . . .
Fizzle. Field is now rising quite fast. Density is rather high.

Fill to 20ms.
------------------------------------------------------------------------------
980113007 HUTCH PHYSICS_OPERATOR 13-JAN-1998 10:15:53.16
. . . . . . . . . . . . . . . . . . . .
Plasma. Density rises extremely quickly in first 200ms.
Lots of banging on inner limiter.
Got up to 2.8MW of RF, but no heating worth speaking of.
D_alpha rises during the RF.
No H-Mode, no sawteeth.
P_rad bolo is about .5MW, this is less than the 2pi.

Lower PG3 initial puff to 70V from 95V.
------------------------------------------------------------------------------
980113008 HUTCH PHYSICS_OPERATOR 13-JAN-1998 10:26:41.18
. . . . . . . . . . . . . . . . . . . .
Fizzle 45 kA. 4e18 density, Breakdown seems slightly later.
Yes, about 8ms.

Fill puff to 25ms.
------------------------------------------------------------------------------
980113009 HUTCH PHYSICS_OPERATOR 13-JAN-1998 10:34:48.92
. . . . . . . . . . . . . . . . . . . .
Fizzle. Initial Bz is higher than before.

EF4 back to 1345.
------------------------------------------------------------------------------
980113010 HUTCH PHYSICS_OPERATOR 13-JAN-1998 10:50:58.88
. . . . . . . . . . . . . . . . . . . .
Fizzle. Slightly earlier breakdown, 6 ms.. Only 40 kA.
Density gets to 6e18.

Fill to 20 ms.
------------------------------------------------------------------------------
980113011 HUTCH PHYSICS_OPERATOR 13-JAN-1998 10:58:52.30
. . . . . . . . . . . . . . . . . . . .
Fizzle. Sits at 45kA for 8ms before dying.

Rcur offset to 5800 from 6300.
------------------------------------------------------------------------------
980113012 HUTCH PHYSICS_OPERATOR 13-JAN-1998 11:19:08.44
. . . . . . . . . . . . . . . . . . . .
Plasma. Early over-density is sort of fixed.
RF works.
Some signs of heating.
H-mode transitions at the highest power.
Small sawteeth before and during RF.

Reduce nl04 setting to 1.0 from 1.4e20
Add pulse gas 5 Hydrogen puff at 20ms 100V. 2 psi.
Didn't finish the gas plenum purge so no H2 this shot.
------------------------------------------------------------------------------
980113013 HUTCH PHYSICS_OPERATOR 13-JAN-1998 11:42:45.67
. . . . . . . . . . . . . . . . . . . .
Plasma. H-modes and RF tripping.
Plasma is jerked around by the transitions. No feedback.

RCur offset to 5500 in segment 1.
Rcur moved out 2mm to .669m.
Leave Hydrogen disabled. On Rejean's instructions.

------------------------------------------------------------------------------
980113014 HUTCH PHYSICS_OPERATOR 13-JAN-1998 11:47:01.39
. . . . . . . . . . . . . . . . . . . .
TF trip prior to shot and back out.
Power supply dud. No EF1, no OH1.
------------------------------------------------------------------------------
980113015 HUTCH PHYSICS_OPERATOR 13-JAN-1998 12:00:06.89
. . . . . . . . . . . . . . . . . . . .
Fizzle.

Br offset to .0065
------------------------------------------------------------------------------
980113016 HUTCH PHYSICS_OPERATOR 13-JAN-1998 12:18:30.23
. . . . . . . . . . . . . . . . . . . .
Plasma.
Many little H-modes at 2.4 MW.

------------------------------------------------------------------------------
980113017 HUTCH PHYSICS_OPERATOR 13-JAN-1998 12:29:50.76
. . . . . . . . . . . . . . . . . . . .
Plasma. Disrupts at 0.5s. A brick.

Fill B-side lower Argon plenum to 1 psi. Pulse 24ms.
------------------------------------------------------------------------------
980113018 HUTCH PHYSICS_OPERATOR 13-JAN-1998 12:41:35.70
. . . . . . . . . . . . . . . . . . . .
Fizzle at 45kA.
We are informed that the hydrogen is 10 times lower than last week.
Hydrogen not enabled prior to this shot.

Br offset to 6.2mT.
Rcur offset to 5800.
Enable the Hydrogen puff. It is at about .275s.
------------------------------------------------------------------------------
980113019 HUTCH PHYSICS_OPERATOR 13-JAN-1998 12:52:59.84
. . . . . . . . . . . . . . . . . . . .
Fizzle.

Fill puff to 17ms.
------------------------------------------------------------------------------
980113020 HUTCH PHYSICS_OPERATOR 13-JAN-1998 13:05:13.58
. . . . . . . . . . . . . . . . . . . .
Fizzle. Density 3e18. Long pause. Later breakdown.

Fill back to 20ms.
EF3 to 1500 V at 15ms.
------------------------------------------------------------------------------
980113021 HUTCH PHYSICS_OPERATOR 13-JAN-1998 13:09:00.64
. . . . . . . . . . . . . . . . . . . .
Fizzle.

EF3 to 1500V at 10ms.
------------------------------------------------------------------------------
980113021 HUTCH PHYSICS_OPERATOR 13-JAN-1998 13:13:01.62
. . . . . . . . . . . . . . . . . . . .
Fizzle

EF3 to 2500V at 10-16ms.
------------------------------------------------------------------------------
980113023 HUTCH PHYSICS_OPERATOR 13-JAN-1998 13:29:47.43
. . . . . . . . . . . . . . . . . . . .
Fizzle.

Rejean calls for attempts at initiation with deuterium fill.
Reload segment 1 from 980107025. Redo the pg3 lowering to 70V.

Summary on Helium initiation:
Current rise is initially very fast, and needs a high B_z ramp rate in the first
15ms. We were then getting current pauses at 45kA, that were unexplained.
Clearly more development is needed if we want to get robust Helium startup.
------------------------------------------------------------------------------
980113024 HUTCH PHYSICS_OPERATOR 13-JAN-1998 13:55:21.48
. . . . . . . . . . . . . . . . . . . .
Plasma. Runaway problem at start because density only 1e18.
Seems to touch limiter at time of "brick".

Pulled plasma in at .47s.
------------------------------------------------------------------------------
980113025 HUTCH PHYSICS_OPERATOR 13-JAN-1998 13:55:36.14
. . . . . . . . . . . . . . . . . . . .
PS dud.
------------------------------------------------------------------------------
980113026 HUTCH PHYSICS_OPERATOR 13-JAN-1998 14:15:06.77
. . . . . . . . . . . . . . . . . . . .
Plasma.
Multiple H-modes.

nl04 to .7e20
fill to 19ms.
Hydrogen puff to 30ms.

------------------------------------------------------------------------------
980113027 HUTCH PHYSICS_OPERATOR 13-JAN-1998 14:28:11.53
. . . . . . . . . . . . . . . . . . . .
Plasma. Got 9e19 nl04. Disrupts at 1.33s.
Hydrogen may be visible on the H-alpha trace.
Lots of Mo still. Still getting non-thermals.

Hydrogen pulse to 5ms.
nl04 to 0.5e20.
------------------------------------------------------------------------------
980113028 HUTCH PHYSICS_OPERATOR 13-JAN-1998 14:41:44.85
. . . . . . . . . . . . . . . . . . . .
Plasma disrupts at 1.15s. A brick.
No H-mode.

Move Hydrogen pulse to .42 to .44s.
Argon pulse to 20ms.
------------------------------------------------------------------------------
980113029 HUTCH PHYSICS_OPERATOR 13-JAN-1998 14:53:50.61
. . . . . . . . . . . . . . . . . . . .
Plasma Disrupts at 1s.
Little H-modes but not significant.

nl04 to 1.4e20.
------------------------------------------------------------------------------
980113030 HUTCH PHYSICS_OPERATOR 13-JAN-1998 15:09:16.63
. . . . . . . . . . . . . . . . . . . .
Plasma till 1.56s.
Multiple H-modes and RF trips.

nl04 to 2e20. puff V to 80 in segment 1.
------------------------------------------------------------------------------
980113031 HUTCH PHYSICS_OPERATOR 13-JAN-1998 15:22:07.77
. . . . . . . . . . . . . . . . . . . .
Plasma till 1.4s.
Got up to 2e20 density.
No H-mode.

nl04 to 1.2e20
Hydrogen puff to 40 ms.
------------------------------------------------------------------------------
980113032 HUTCH PHYSICS_OPERATOR 13-JAN-1998 15:34:31.76
. . . . . . . . . . . . . . . . . . . .
Plasma. RF puts the density up too much even without Hmode.

Lower the density a tad more.
------------------------------------------------------------------------------
980113033 HUTCH PHYSICS_OPERATOR 13-JAN-1998 15:42:34.82
. . . . . . . . . . . . . . . . . . . .
PS dud.
------------------------------------------------------------------------------
980113034 HUTCH PHYSICS_OPERATOR 13-JAN-1998 15:58:31.78
. . . . . . . . . . . . . . . . . . . .
Plasma.

Hydrogen puff to 80ms.
Lower nl04 to just under 1.e20.
------------------------------------------------------------------------------
980113035 HUTCH PHYSICS_OPERATOR 13-JAN-1998 16:11:47.99
. . . . . . . . . . . . . . . . . . . .
Plasma. Many small H-modes.

Use fill-puff valve to puff D2 at 100V for 30-100ms.
Ar puff to 25ms.
------------------------------------------------------------------------------
980113036 HUTCH PHYSICS_OPERATOR 13-JAN-1998 16:17:35.93
. . . . . . . . . . . . . . . . . . . .
Fizzle.

Increase fill puff to 24ms.
------------------------------------------------------------------------------
980113037 HUTCH PHYSICS_OPERATOR 13-JAN-1998 16:37:30.23
. . . . . . . . . . . .

Entered: Jul 7 2004 04:36:58:740PM

Author: To Be Determined

. . . . . . . .
Plasma.

PG 4 100V 0-250ms in segment 2.
------------------------------------------------------------------------------
980113038 HUTCH PHYSICS_OPERATOR 13-JAN-1998 16:49:39.69
. . . . . . . . . . . . . . . . . . . .
Plasma.

D puff to 0-0.7s.
Rcur offset to 6500 from 6300 in segment 1.
------------------------------------------------------------------------------
980113039 HUTCH PHYSICS_OPERATOR 13-JAN-1998 16:58:28.95
. . . . . . . . . . . . . . . . . . . .
Plasma.

Increase the fill valve pressure to 15psi (pg4)
Lower the fill puff length to 13ms.
Reduce the PG3 puff valve to about 55V during first 100ms.
------------------------------------------------------------------------------
980113040 HUTCH PHYSICS_OPERATOR 13-JAN-1998 17:06:22.87
. . . . . . . . . . . . . . . . . . . .
Plasma.
Sustained H-mode. Partially EDA. Higher stored energy.
Prad bolo higher than 2pi. Moly signal reduced except during the H-mode.

Session Leader Comments

Jan 13 1998 09:10:15:090AM Rejean Boivin MP 154
Helium H modes

Run Plan

ECDC in helium as much as possible to remove deuterium from
walls.

1) Tuesday OH test shot

2) Establish helium plasma
Use shot from 951215 run as a baseline. (other helium run)
But we will take
980107025 for ease of implementation
with an outer gap of 1cm no more.
Helium fill.
Start at density of nel~1x10^20.
Tweak amount of Hydrogen if needed for breakdown.
RF to reliable maximum power in 3-4 steps (100 msec each)
1-2 steps down if possible for hysteresis.
A slow ramp starting at 1 or 2 MW is also a possibility
Flattop til 1.2 sec.

3) If successful, scan density, lower at first, higher after
nel~ 0.7
0.4 (lower?)
0.5
0.9
1.4
1.8
2.2
and some in between if any interesting change is observed.
Amanda could also use a TF ramp or 2 for pedestal information.
(couple of shots)
Bruce L. would also like to try a high density detachment
without RF (1-2 shots).

4) Scan deuterium content by increasing deuterium
concentration from 0% to 100% by 10ish% increment.
Number of shots will depend on actual concentration
due to wall loading.

Jan 13 1998 09:18:00:980AM 980113002 Rejean Boivin
That's a DUD.

For those who care, the ratiomatic is calibrated
for D2. Multiply by 2 for Helium gas.

Jan 13 1998 09:28:51:110AM 980113003 Rejean Boivin
Fizzle with breakdown in Helium.

Jan 13 1998 11:14:43:980AM 980113007 Rejean Boivin
Plasma!

No H modes in spite of large power.
Outer gap is very large so we are not
sure where the power goes.

Jan 13 1998 11:13:48:310AM 980113012 Rejean Boivin
Got H modes! (3)

Density is still too high, reduce it for next shot.

We are removing deuterium (look at Dalpha trace)
from somwhere, not necessarily antenna.

Jan 13 1998 11:42:57:100AM 980113013 Rejean Boivin
Another good one.

Many small H modes, RF trips with the H modes,
low loading. Will reduce gap a bit more.

Jan 13 1998 11:55:07:700AM 980113014 Rejean Boivin
Dud, followed a backout from INIT.

Jan 13 1998 11:55:33:350AM 980113015 Rejean Boivin
Fizzle.

Jan 13 1998 01:05:34:870PM 980113016 Rejean Boivin
Good Plasma.
Many small H modes.
Some indirect information that the SOL may be much "shorter",
will try to confirm that with the FSP.
Something came in at 0.75 sec.

Jan 13 1998 01:20:23:970PM 980113023 Rejean Boivin
Fizzle.
Will try a breakdown in deuterium instead.
Fill with Helium after (as in 951215).

Jan 13 1998 01:41:37:660PM 980113024 Rejean Boivin
Plasma,

Breakdown in deuterium
Large run-away population at beginning
Big injection at 0.47 sec when plasma touches limiter/out.
No H mode.

Jan 13 1998 01:56:50:480PM 980113025 Rejean Boivin
Duddy Duddy Dud

Followed a backoff from INIT....

Jan 13 1998 02:10:38:000PM 980113026 Rejean Boivin
Good Plasma,

6 H modes,

go to lower density.

Lots of Moly though.

Jan 13 1998 02:48:18:220PM 980113027 Rejean Boivin
Good Plasma,

H mode towards the end of the RF pulse,
kissing the threshold.

Go to lower density next shot

Jan 13 1998 02:46:50:840PM 980113028 Rejean Boivin
Good Plasma,

No H mode, but trying to do it...

Disrupted before the end of the flattop.
Edge temoerature is high though.

Try higher power next shot.

Jan 13 1998 02:47:38:550PM 980113029 Rejean Boivin
Good Plasma,

No H mode, but almost made numerous times.

Disrupted before the end of the flattop.

Go to higher density for next shot.

Jan 13 1998 03:30:07:030PM 980113030 Rejean Boivin
Good Plasma,

Higher density, D alpha is back "up"!!!

Jan 13 1998 03:31:02:370PM 980113031 Rejean Boivin
Plasma, high density, no H mode

Jan 13 1998 03:31:37:260PM 980113032 Rejean Boivin
Plasma,

Back down in density to give a TF ramp and pedestal
measurement for Amanda.

Jan 13 1998 03:37:30:170PM 980113033 Rejean Boivin
Duddy Duddy Dud.

Jan 13 1998 04:14:50:640PM 980113034 Rejean Boivin
Plasma,

medium density, try a TF ramp for pedestal measurement.

Jan 13 1998 04:15:20:710PM 980113035 Rejean Boivin
Plasma,

medium density, slightly lower
got a better ramp for Amanda

Jan 13 1998 04:15:35:870PM 980113036 Rejean Boivin
Fizzle

Jan 13 1998 05:10:11:560PM 980113037 Rejean Boivin
Plasma,
Try more deuterium

Jan 13 1998 05:10:43:660PM 980113038 Rejean Boivin
Plasma,
Even more deuterium

Jan 13 1998 05:11:01:560PM 980113039 Rejean Boivin
Plasma,
We like it, Even more deuterium

Jan 13 1998 05:11:39:630PM 980113040 Rejean Boivin
Plasma,
More deuterium Igor (aka Ian), More! Maybe close to 50-50 now

Physics Operator Comments

Jan 13 1998 08:28:38:780AM Ian Hutchinson 13 Jan 98 MP 154 H-modes in Helium plasmas.

Starting with Helium initiation attempts.
Gases available.
SG1 Hydrogen
SG2 D2
SG3 Helium-4
SG4 Argon
SG5 Nitrogen
SG6 Helium-3

Did cold start.
Gas: B-top He 6.2psi
K-side He 30 psi.
Fill pulse to 20 ms.

Jan 13 1998 08:54:07:960AM Ian Hutchinson Load from
980107025
Gas pulse to 20 from 15ms.
Note, we had many hours of He ECDC over the weekend in preparation
for this run.

Jan 13 1998 09:05:59:520AM 980113001 Ian Hutchinson OH test. OH2U shows the usual oscillations even during this test under PLC
control.

Jan 13 1998 09:12:32:330AM 980113002 Ian Hutchinson Power supply dud. EF3 not switched on.

Jan 13 1998 09:17:28:360AM 980113002 Ian Hutchinson Pressure on the ratiomatic reads .026 mtorr. It is stated that this should be
multiplied by a factor of 2. So the real pressure is about .05 mtorr.

Jan 13 1998 09:33:03:840AM 980113003 Ian Hutchinson Breakdown at 5ms and rapid initial Ip rise to 35kA at 9ms, but then fizzles.
Bz is probably rising too slowly for the rate of current rise.
D_alpha trace peaks at 0.06 versus 0.12 for the D shot. This is surprisingly high.

Fill puff to 30 ms.

Jan 13 1998 09:41:43:090AM 980113004 Ian Hutchinson Fizzle. Breakdown. Current rise still extremely fast.
D_a drops to .045, Ratiomatic .04 mtorr.

EF3 voltage to 3000V at 4-9ms.

Jan 13 1998 09:50:08:280AM 980113005 Ian Hutchinson Fizzle. Not changed very much but the B_z rise quicker.

EF4 to -1335 from -1345.
EF3 to 3000V at 3ms.

Jan 13 1998 10:01:31:160AM 980113006 Ian Hutchinson Fizzle. Field is now rising quite fast. Density is rather high.

Fill to 20ms.

Jan 13 1998 10:15:53:160AM 980113007 Ian Hutchinson Plasma. Density rises extremely quickly in first 200ms.
Lots of banging on inner limiter.
Got up to 2.8MW of RF, but no heating worth speaking of.
D_alpha rises during the RF.
No H-Mode, no sawteeth.
P_rad bolo is about .5MW, this is less than the 2pi.

Lower PG3 initial puff to 70V from 95V.

Jan 13 1998 10:26:41:180AM 980113008 Ian Hutchinson Fizzle 45 kA. 4e18 density, Breakdown seems slightly later.
Yes, about 8ms.

Fill puff to 25ms.

Jan 13 1998 10:34:48:920AM 980113009 Ian Hutchinson Fizzle. Initial Bz is higher than before.

EF4 back to 1345.

Jan 13 1998 10:50:58:880AM 980113010 Ian Hutchinson Fizzle. Slightly earlier breakdown, 6 ms.. Only 40 kA.
Density gets to 6e18.

Fill to 20 ms.

Jan 13 1998 10:58:52:300AM 980113011 Ian Hutchinson Fizzle. Sits at 45kA for 8ms before dying.

Rcur offset to 5800 from 6300.

Jan 13 1998 11:19:08:440AM 980113012 Ian Hutchinson Plasma. Early over-density is sort of fixed.
RF works.
Some signs of heating.
H-mode transitions at the highest power.
Small sawteeth before and during RF.

Reduce nl04 setting to 1.0 from 1.4e20
Add pulse gas 5 Hydrogen puff at 20ms 100V. 2 psi.
Didn't finish the gas plenum purge so no H2 this shot.

Jan 13 1998 11:42:45:670AM 980113013 Ian Hutchinson Plasma. H-modes and RF tripping.
Plasma is jerked around by the transitions. No feedback.

RCur offset to 5500 in segment 1.
Rcur moved out 2mm to .669m.
Leave Hydrogen disabled. On Rejean's instructions.

Jan 13 1998 11:47:01:390AM 980113014 Ian Hutchinson TF trip prior to shot and back out.
Power supply dud. No EF1, no OH1.

Jan 13 1998 12:00:06:890PM 980113015 Ian Hutchinson Fizzle.

Br offset to .0065

Jan 13 1998 12:18:30:230PM 980113016 Ian Hutchinson Plasma.
Many little H-modes at 2.4 MW.

Jan 13 1998 12:29:50:760PM 980113017 Ian Hutchinson Plasma. Disrupts at 0.5s. A brick.

Fill B-side lower Argon plenum to 1 psi. Pulse 24ms.

Jan 13 1998 12:41:35:700PM 980113018 Ian Hutchinson Fizzle at 45kA.
We are informed that the hydrogen is 10 times lower than last week.
Hydrogen not enabled prior to this shot.

Br offset to 6.2mT.
Rcur offset to 5800.
Enable the Hydrogen puff. It is at about .275s.

Jan 13 1998 12:52:59:840PM 980113019 Ian Hutchinson Fizzle.

Fill puff to 17ms.

Jan 13 1998 01:05:13:580PM 980113020 Ian Hutchinson Fizzle. Density 3e18. Long pause. Later breakdown.

Fill back to 20ms.
EF3 to 1500 V at 15ms.

Jan 13 1998 01:09:00:640PM 980113021 Ian Hutchinson Fizzle.

EF3 to 1500V at 10ms.

Jan 13 1998 01:13:01:620PM 980113021 Ian Hutchinson Fizzle

EF3 to 2500V at 10-16ms.

Jan 13 1998 01:29:47:430PM 980113023 Ian Hutchinson Fizzle.

Rejean calls for attempts at initiation with deuterium fill.
Reload segment 1 from 980107025. Redo the pg3 lowering to 70V.

Summary on Helium initiation:
Current rise is initially very fast, and needs a high B_z ramp rate in the first
15ms. We were then getting current pauses at 45kA, that were unexplained.
Clearly more development is needed if we want to get robust Helium startup.

Jan 13 1998 01:55:21:480PM 980113024 Ian Hutchinson Plasma. Runaway problem at start because density only 1e18.
Seems to touch limiter at time of "brick".

Pulled plasma in at .47s.

Jan 13 1998 01:55:36:140PM 980113025 Ian Hutchinson PS dud.

Jan 13 1998 02:15:06:770PM 980113026 Ian Hutchinson Plasma.
Multiple H-modes.

nl04 to .7e20
fill to 19ms.
Hydrogen puff to 30ms.

Jan 13 1998 02:28:11:530PM 980113027 Ian Hutchinson Plasma. Got 9e19 nl04. Disrupts at 1.33s.
Hydrogen may be visible on the H-alpha trace.
Lots of Mo still. Still getting non-thermals.

Hydrogen pulse to 5ms.
nl04 to 0.5e20.

Jan 13 1998 02:41:44:850PM 980113028 Ian Hutchinson Plasma disrupts at 1.15s. A brick.
No H-mode.

Move Hydrogen pulse to .42 to .44s.
Argon pulse to 20ms.

Jan 13 1998 02:53:50:610PM 980113029 Ian Hutchinson Plasma Disrupts at 1s.
Little H-modes but not significant.

nl04 to 1.4e20.

Jan 13 1998 03:09:16:630PM 980113030 Ian Hutchinson Plasma till 1.56s.
Multiple H-modes and RF trips.

nl04 to 2e20. puff V to 80 in segment 1.

Jan 13 1998 03:22:07:770PM 980113031 Ian Hutchinson Plasma till 1.4s.
Got up to 2e20 density.
No H-mode.

nl04 to 1.2e20
Hydrogen puff to 40 ms.

Jan 13 1998 03:34:31:760PM 980113032 Ian Hutchinson Plasma. RF puts the density up too much even without Hmode.

Lower the density a tad more.

Jan 13 1998 03:42:34:820PM 980113033 Ian Hutchinson PS dud.

Jan 13 1998 03:58:31:780PM 980113034 Ian Hutchinson Plasma.

Hydrogen puff to 80ms.
Lower nl04 to just under 1.e20.

Jan 13 1998 04:11:47:990PM 980113035 Ian Hutchinson Plasma. Many small H-modes.

Use fill-puff valve to puff D2 at 100V for 30-100ms.
Ar puff to 25ms.

Jan 13 1998 04:17:35:930PM 980113036 Ian Hutchinson Fizzle.

Increase fill puff to 24ms.

Jan 13 1998 04:37:30:230PM 980113037 Ian Hutchinson Plasma.

PG 4 100V 0-250ms in segment 2.

Jan 13 1998 04:49:39:690PM 980113038 Ian Hutchinson Plasma.

D puff to 0-0.7s.
Rcur offset to 6500 from 6300 in segment 1.

Jan 13 1998 04:58:28:950PM 980113039 Ian Hutchinson Plasma.

Increase the fill valve pressure to 15psi (pg4)
Lower the fill puff length to 13ms.
Reduce the PG3 puff valve to about 55V during first 100ms.

Jan 13 1998 05:06:22:870PM 980113040 Ian Hutchinson Plasma.
Sustained H-mode. Partially EDA. Higher stored energy.
Prad bolo higher than 2pi. Moly signal reduced except during the H-mode.

Engineering Operator Comments

Shot Time Type Status Comment

1 08:57:59:970AM Test Ok oh test ok

2 09:09:31:070AM Plasma Ok EF3 not enabled

3 09:18:17:490AM Plasma Ok no faults

4 09:30:52:430AM Plasma Ok no faults

5 09:40:39:580AM Plasma Ok no faults

6 09:51:24:900AM Plasma Ok no faults

7 10:00:00:030AM Plasma Ok no faults

8 10:16:30:340AM Plasma Ok no faults

9 10:24:40:420AM Plasma Ok no faults

10 10:32:41:000AM Plasma Ok no faults/ cell access

11 10:48:59:930AM Plasma Ok no faults

12 10:57:27:320AM Plasma Ok no faults/plasma

13 11:20:36:070AM Plasma Ok no faults/plasma

14 11:38:11:010AM Plasma Bad tf self powered ck ioc fired in init,went to recool- retry shot nooh1 or

15 11:53:02:820AM Plasma Ok no faults

16 12:02:30:700PM Plasma Ok no faults/plasma

17 12:16:57:170PM Plasma Ok no faults

18 12:28:53:810PM Plasma Ok no faults

19 12:40:17:940PM Plasma Ok

20 12:49:24:910PM Plasma Ok no faults

21 12:58:38:890PM Plasma Ok

22 01:07:34:380PM Plasma Ok

23 01:15:34:490PM Plasma Ok

24 01:29:22:750PM Plasma Ok

25 01:42:38:500PM Plasma Bad no tf, oh1, ef1s

26 02:00:31:720PM Plasma Ok

27 02:12:59:890PM Plasma Ok

28 02:26:17:040PM Plasma Ok

29 02:40:03:900PM Plasma Ok

30 02:52:05:230PM Plasma Ok

31 03:06:01:700PM Plasma Ok

32 03:20:04:420PM Plasma Ok

33 03:32:55:930PM Plasma Bad tf didn't fire

34 03:42:25:280PM Plasma Ok

35 03:54:30:060PM Plasma Ok

36 04:07:27:570PM Plasma Ok

37 04:16:15:300PM Plasma Ok

38 04:29:11:810PM Plasma Ok

39 04:44:09:700PM Plasma Ok

40 04:57:04:110PM Plasma Ok

Session Leader Comments
Jan 13 1998 09:10:15:090AM		Rejean Boivin	MP 154 Helium H modes Run Plan ECDC in helium as much as possible to remove deuterium from walls. 1) Tuesday OH test shot 2) Establish helium plasma Use shot from 951215 run as a baseline. (other helium run) But we will take 980107025 for ease of implementation with an outer gap of 1cm no more. Helium fill. Start at density of nel~1x10^20. Tweak amount of Hydrogen if needed for breakdown. RF to reliable maximum power in 3-4 steps (100 msec each) 1-2 steps down if possible for hysteresis. A slow ramp starting at 1 or 2 MW is also a possibility Flattop til 1.2 sec. 3) If successful, scan density, lower at first, higher after nel~ 0.7 0.4 (lower?) 0.5 0.9 1.4 1.8 2.2 and some in between if any interesting change is observed. Amanda could also use a TF ramp or 2 for pedestal information. (couple of shots) Bruce L. would also like to try a high density detachment without RF (1-2 shots). 4) Scan deuterium content by increasing deuterium concentration from 0% to 100% by 10ish% increment. Number of shots will depend on actual concentration due to wall loading.
Jan 13 1998 09:18:00:980AM	980113002	Rejean Boivin	That's a DUD. For those who care, the ratiomatic is calibrated for D2. Multiply by 2 for Helium gas.
Jan 13 1998 09:28:51:110AM	980113003	Rejean Boivin	Fizzle with breakdown in Helium.
Jan 13 1998 11:14:43:980AM	980113007	Rejean Boivin	Plasma! No H modes in spite of large power. Outer gap is very large so we are not sure where the power goes.
Jan 13 1998 11:13:48:310AM	980113012	Rejean Boivin	Got H modes! (3) Density is still too high, reduce it for next shot. We are removing deuterium (look at Dalpha trace) from somwhere, not necessarily antenna.
Jan 13 1998 11:42:57:100AM	980113013	Rejean Boivin	Another good one. Many small H modes, RF trips with the H modes, low loading. Will reduce gap a bit more.
Jan 13 1998 11:55:07:700AM	980113014	Rejean Boivin	Dud, followed a backout from INIT.
Jan 13 1998 11:55:33:350AM	980113015	Rejean Boivin	Fizzle.
Jan 13 1998 01:05:34:870PM	980113016	Rejean Boivin	Good Plasma. Many small H modes. Some indirect information that the SOL may be much "shorter", will try to confirm that with the FSP. Something came in at 0.75 sec.
Jan 13 1998 01:20:23:970PM	980113023	Rejean Boivin	Fizzle. Will try a breakdown in deuterium instead. Fill with Helium after (as in 951215).
Jan 13 1998 01:41:37:660PM	980113024	Rejean Boivin	Plasma, Breakdown in deuterium Large run-away population at beginning Big injection at 0.47 sec when plasma touches limiter/out. No H mode.
Jan 13 1998 01:56:50:480PM	980113025	Rejean Boivin	Duddy Duddy Dud Followed a backoff from INIT....
Jan 13 1998 02:10:38:000PM	980113026	Rejean Boivin	Good Plasma, 6 H modes, go to lower density. Lots of Moly though.
Jan 13 1998 02:48:18:220PM	980113027	Rejean Boivin	Good Plasma, H mode towards the end of the RF pulse, kissing the threshold. Go to lower density next shot
Jan 13 1998 02:46:50:840PM	980113028	Rejean Boivin	Good Plasma, No H mode, but trying to do it... Disrupted before the end of the flattop. Edge temoerature is high though. Try higher power next shot.
Jan 13 1998 02:47:38:550PM	980113029	Rejean Boivin	Good Plasma, No H mode, but almost made numerous times. Disrupted before the end of the flattop. Go to higher density for next shot.
Jan 13 1998 03:30:07:030PM	980113030	Rejean Boivin	Good Plasma, Higher density, D alpha is back "up"!!!
Jan 13 1998 03:31:02:370PM	980113031	Rejean Boivin	Plasma, high density, no H mode
Jan 13 1998 03:31:37:260PM	980113032	Rejean Boivin	Plasma, Back down in density to give a TF ramp and pedestal measurement for Amanda.
Jan 13 1998 03:37:30:170PM	980113033	Rejean Boivin	Duddy Duddy Dud.
Jan 13 1998 04:14:50:640PM	980113034	Rejean Boivin	Plasma, medium density, try a TF ramp for pedestal measurement.
Jan 13 1998 04:15:20:710PM	980113035	Rejean Boivin	Plasma, medium density, slightly lower got a better ramp for Amanda
Jan 13 1998 04:15:35:870PM	980113036	Rejean Boivin	Fizzle
Jan 13 1998 05:10:11:560PM	980113037	Rejean Boivin	Plasma, Try more deuterium
Jan 13 1998 05:10:43:660PM	980113038	Rejean Boivin	Plasma, Even more deuterium
Jan 13 1998 05:11:01:560PM	980113039	Rejean Boivin	Plasma, We like it, Even more deuterium
Jan 13 1998 05:11:39:630PM	980113040	Rejean Boivin	Plasma, More deuterium Igor (aka Ian), More! Maybe close to 50-50 now

Physics Operator Comments
Jan 13 1998 08:28:38:780AM		Ian Hutchinson	13 Jan 98 MP 154 H-modes in Helium plasmas. Starting with Helium initiation attempts. Gases available. SG1 Hydrogen SG2 D2 SG3 Helium-4 SG4 Argon SG5 Nitrogen SG6 Helium-3 Did cold start. Gas: B-top He 6.2psi K-side He 30 psi. Fill pulse to 20 ms.
Jan 13 1998 08:54:07:960AM		Ian Hutchinson	Load from 980107025 Gas pulse to 20 from 15ms. Note, we had many hours of He ECDC over the weekend in preparation for this run.
Jan 13 1998 09:05:59:520AM	980113001	Ian Hutchinson	OH test. OH2U shows the usual oscillations even during this test under PLC control.
Jan 13 1998 09:12:32:330AM	980113002	Ian Hutchinson	Power supply dud. EF3 not switched on.
Jan 13 1998 09:17:28:360AM	980113002	Ian Hutchinson	Pressure on the ratiomatic reads .026 mtorr. It is stated that this should be multiplied by a factor of 2. So the real pressure is about .05 mtorr.
Jan 13 1998 09:33:03:840AM	980113003	Ian Hutchinson	Breakdown at 5ms and rapid initial Ip rise to 35kA at 9ms, but then fizzles. Bz is probably rising too slowly for the rate of current rise. D_alpha trace peaks at 0.06 versus 0.12 for the D shot. This is surprisingly high. Fill puff to 30 ms.
Jan 13 1998 09:41:43:090AM	980113004	Ian Hutchinson	Fizzle. Breakdown. Current rise still extremely fast. D_a drops to .045, Ratiomatic .04 mtorr. EF3 voltage to 3000V at 4-9ms.
Jan 13 1998 09:50:08:280AM	980113005	Ian Hutchinson	Fizzle. Not changed very much but the B_z rise quicker. EF4 to -1335 from -1345. EF3 to 3000V at 3ms.
Jan 13 1998 10:01:31:160AM	980113006	Ian Hutchinson	Fizzle. Field is now rising quite fast. Density is rather high. Fill to 20ms.
Jan 13 1998 10:15:53:160AM	980113007	Ian Hutchinson	Plasma. Density rises extremely quickly in first 200ms. Lots of banging on inner limiter. Got up to 2.8MW of RF, but no heating worth speaking of. D_alpha rises during the RF. No H-Mode, no sawteeth. P_rad bolo is about .5MW, this is less than the 2pi. Lower PG3 initial puff to 70V from 95V.
Jan 13 1998 10:26:41:180AM	980113008	Ian Hutchinson	Fizzle 45 kA. 4e18 density, Breakdown seems slightly later. Yes, about 8ms. Fill puff to 25ms.
Jan 13 1998 10:34:48:920AM	980113009	Ian Hutchinson	Fizzle. Initial Bz is higher than before. EF4 back to 1345.
Jan 13 1998 10:50:58:880AM	980113010	Ian Hutchinson	Fizzle. Slightly earlier breakdown, 6 ms.. Only 40 kA. Density gets to 6e18. Fill to 20 ms.
Jan 13 1998 10:58:52:300AM	980113011	Ian Hutchinson	Fizzle. Sits at 45kA for 8ms before dying. Rcur offset to 5800 from 6300.
Jan 13 1998 11:19:08:440AM	980113012	Ian Hutchinson	Plasma. Early over-density is sort of fixed. RF works. Some signs of heating. H-mode transitions at the highest power. Small sawteeth before and during RF. Reduce nl04 setting to 1.0 from 1.4e20 Add pulse gas 5 Hydrogen puff at 20ms 100V. 2 psi. Didn't finish the gas plenum purge so no H2 this shot.
Jan 13 1998 11:42:45:670AM	980113013	Ian Hutchinson	Plasma. H-modes and RF tripping. Plasma is jerked around by the transitions. No feedback. RCur offset to 5500 in segment 1. Rcur moved out 2mm to .669m. Leave Hydrogen disabled. On Rejean's instructions.
Jan 13 1998 11:47:01:390AM	980113014	Ian Hutchinson	TF trip prior to shot and back out. Power supply dud. No EF1, no OH1.
Jan 13 1998 12:00:06:890PM	980113015	Ian Hutchinson	Fizzle. Br offset to .0065
Jan 13 1998 12:18:30:230PM	980113016	Ian Hutchinson	Plasma. Many little H-modes at 2.4 MW.
Jan 13 1998 12:29:50:760PM	980113017	Ian Hutchinson	Plasma. Disrupts at 0.5s. A brick. Fill B-side lower Argon plenum to 1 psi. Pulse 24ms.
Jan 13 1998 12:41:35:700PM	980113018	Ian Hutchinson	Fizzle at 45kA. We are informed that the hydrogen is 10 times lower than last week. Hydrogen not enabled prior to this shot. Br offset to 6.2mT. Rcur offset to 5800. Enable the Hydrogen puff. It is at about .275s.
Jan 13 1998 12:52:59:840PM	980113019	Ian Hutchinson	Fizzle. Fill puff to 17ms.
Jan 13 1998 01:05:13:580PM	980113020	Ian Hutchinson	Fizzle. Density 3e18. Long pause. Later breakdown. Fill back to 20ms. EF3 to 1500 V at 15ms.
Jan 13 1998 01:09:00:640PM	980113021	Ian Hutchinson	Fizzle. EF3 to 1500V at 10ms.
Jan 13 1998 01:13:01:620PM	980113021	Ian Hutchinson	Fizzle EF3 to 2500V at 10-16ms.
Jan 13 1998 01:29:47:430PM	980113023	Ian Hutchinson	Fizzle. Rejean calls for attempts at initiation with deuterium fill. Reload segment 1 from 980107025. Redo the pg3 lowering to 70V. Summary on Helium initiation: Current rise is initially very fast, and needs a high B_z ramp rate in the first 15ms. We were then getting current pauses at 45kA, that were unexplained. Clearly more development is needed if we want to get robust Helium startup.
Jan 13 1998 01:55:21:480PM	980113024	Ian Hutchinson	Plasma. Runaway problem at start because density only 1e18. Seems to touch limiter at time of "brick". Pulled plasma in at .47s.
Jan 13 1998 01:55:36:140PM	980113025	Ian Hutchinson	PS dud.
Jan 13 1998 02:15:06:770PM	980113026	Ian Hutchinson	Plasma. Multiple H-modes. nl04 to .7e20 fill to 19ms. Hydrogen puff to 30ms.
Jan 13 1998 02:28:11:530PM	980113027	Ian Hutchinson	Plasma. Got 9e19 nl04. Disrupts at 1.33s. Hydrogen may be visible on the H-alpha trace. Lots of Mo still. Still getting non-thermals. Hydrogen pulse to 5ms. nl04 to 0.5e20.
Jan 13 1998 02:41:44:850PM	980113028	Ian Hutchinson	Plasma disrupts at 1.15s. A brick. No H-mode. Move Hydrogen pulse to .42 to .44s. Argon pulse to 20ms.
Jan 13 1998 02:53:50:610PM	980113029	Ian Hutchinson	Plasma Disrupts at 1s. Little H-modes but not significant. nl04 to 1.4e20.
Jan 13 1998 03:09:16:630PM	980113030	Ian Hutchinson	Plasma till 1.56s. Multiple H-modes and RF trips. nl04 to 2e20. puff V to 80 in segment 1.
Jan 13 1998 03:22:07:770PM	980113031	Ian Hutchinson	Plasma till 1.4s. Got up to 2e20 density. No H-mode. nl04 to 1.2e20 Hydrogen puff to 40 ms.
Jan 13 1998 03:34:31:760PM	980113032	Ian Hutchinson	Plasma. RF puts the density up too much even without Hmode. Lower the density a tad more.
Jan 13 1998 03:42:34:820PM	980113033	Ian Hutchinson	PS dud.
Jan 13 1998 03:58:31:780PM	980113034	Ian Hutchinson	Plasma. Hydrogen puff to 80ms. Lower nl04 to just under 1.e20.
Jan 13 1998 04:11:47:990PM	980113035	Ian Hutchinson	Plasma. Many small H-modes. Use fill-puff valve to puff D2 at 100V for 30-100ms. Ar puff to 25ms.
Jan 13 1998 04:17:35:930PM	980113036	Ian Hutchinson	Fizzle. Increase fill puff to 24ms.
Jan 13 1998 04:37:30:230PM	980113037	Ian Hutchinson	Plasma. PG 4 100V 0-250ms in segment 2.
Jan 13 1998 04:49:39:690PM	980113038	Ian Hutchinson	Plasma. D puff to 0-0.7s. Rcur offset to 6500 from 6300 in segment 1.
Jan 13 1998 04:58:28:950PM	980113039	Ian Hutchinson	Plasma. Increase the fill valve pressure to 15psi (pg4) Lower the fill puff length to 13ms. Reduce the PG3 puff valve to about 55V during first 100ms.
Jan 13 1998 05:06:22:870PM	980113040	Ian Hutchinson	Plasma. Sustained H-mode. Partially EDA. Higher stored energy. Prad bolo higher than 2pi. Moly signal reduced except during the H-mode.

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	08:57:59:970AM	Test	Ok	oh test ok
2	09:09:31:070AM	Plasma	Ok	EF3 not enabled
3	09:18:17:490AM	Plasma	Ok	no faults
4	09:30:52:430AM	Plasma	Ok	no faults
5	09:40:39:580AM	Plasma	Ok	no faults
6	09:51:24:900AM	Plasma	Ok	no faults
7	10:00:00:030AM	Plasma	Ok	no faults
8	10:16:30:340AM	Plasma	Ok	no faults
9	10:24:40:420AM	Plasma	Ok	no faults
10	10:32:41:000AM	Plasma	Ok	no faults/ cell access
11	10:48:59:930AM	Plasma	Ok	no faults
12	10:57:27:320AM	Plasma	Ok	no faults/plasma
13	11:20:36:070AM	Plasma	Ok	no faults/plasma
14	11:38:11:010AM	Plasma	Bad	tf self powered ck ioc fired in init,went to recool- retry shot nooh1 or
15	11:53:02:820AM	Plasma	Ok	no faults
16	12:02:30:700PM	Plasma	Ok	no faults/plasma
17	12:16:57:170PM	Plasma	Ok	no faults
18	12:28:53:810PM	Plasma	Ok	no faults
19	12:40:17:940PM	Plasma	Ok
20	12:49:24:910PM	Plasma	Ok	no faults
21	12:58:38:890PM	Plasma	Ok
22	01:07:34:380PM	Plasma	Ok
23	01:15:34:490PM	Plasma	Ok
24	01:29:22:750PM	Plasma	Ok
25	01:42:38:500PM	Plasma	Bad	no tf, oh1, ef1s
26	02:00:31:720PM	Plasma	Ok
27	02:12:59:890PM	Plasma	Ok
28	02:26:17:040PM	Plasma	Ok
29	02:40:03:900PM	Plasma	Ok
30	02:52:05:230PM	Plasma	Ok
31	03:06:01:700PM	Plasma	Ok
32	03:20:04:420PM	Plasma	Ok
33	03:32:55:930PM	Plasma	Bad	tf didn't fire
34	03:42:25:280PM	Plasma	Ok
35	03:54:30:060PM	Plasma	Ok
36	04:07:27:570PM	Plasma	Ok
37	04:16:15:300PM	Plasma	Ok
38	04:29:11:810PM	Plasma	Ok
39	04:44:09:700PM	Plasma	Ok
40	04:57:04:110PM	Plasma	Ok