Alcator C-Mod Shot Information for shot 1010719014

Alcator C-Mod Shot Information for shot 1010719014

Miniproposals
Miniproposal:137b
Date Filed: 1/14/1999
Title:Local Edge Threshold for H-Mode (Rev. 2)
First Author:Amanda Hubbard
Session Leader:Amanda Hubbard (shots 1-22)
Miniproposal:289a
Date Filed: 5/2/2001
Title:Investigations of Double Transport Barrier Plasmas
First Author:John Rice
Session Leader:John Rice (shots 1-22)

Operators
Session leader(s):Amanda Hubbard,John Rice
Physics operator(s):Ian Hutchinson
Engineering operator(s):Gary Dekow,Bill Parkin

Data Plots (hover mouse over plot to see maximum value)
Bt (T)
Ip (kA)
nel (m-2)
Te0 (keV)
Wmhd (kJ)
Halpha
Picrf (kW)

Logbook entries for this shot
Topic Entered Author Text
SESSION_LEADER Jul 19 2001 01:21PM Amanda Hubbard Got 2.3 MW, only a few minor trips. This time we had a series of more ELM-free H-modes, with
accumulating impurities and radiation. Not a pretty sight. H/D is up to 0.18!

Next shot, lower Ip to 0.9 MW in an attempt to get EDA conditions.
PHYSICS_OPERATOR Jul 19 2001 01:31PM Ian Hutchinson Plasma. Similar to previous. Disruption in ramp down. Horrid
ragged H-modes.

Ip to .9MA.
RF Jul 19 2001 07:44AM JV1/JV3 Phase balance detector setpoint changed from .5V to 0V, or from +/-65deg. to +/-90deg. Voltage ref. caps on phase reference
and power threshold inputs to comparators were changed from .005 to 1uf.
Same was done on JV2/JV4 phase balance detector.
RF Jul 19 2001 01:24PM Paul Bonoli
BT = 5.3T, Ip~ 1.0 MA, nl_04~0.76x10^20 m^-2

Request:

D: 1.0 MW [0.6,1.5] sec
E: 1.3 MW [0.6,1.5] sec
J: Off

Result: Plasma - H-mode

D: Ran
E: Ran
J:

Note:

Next Shot: Reduce current to 900 kA

Logbook entries for this run
Topic Entered Author Text
SESSION_LEADER Jul 19 2001 04:14PM Amanda Hubbard Physics Run plan for 1010719, MP 287 Asdex H-mode similarity experiment

Goal: To make high density, high power EDA H-modes in a shape identical to
that in ASDEX-Upgrade 'Type II ELM' discharges. This regime,
which was only recently obtained on AUG, appears rather similar to that
obtained on C-Mod when power is increased into EDA H-modes. At reduced powers,
AUG sometimes sees a 'quasi-coherent' mode. We would like to see if the same
behaviour is observed on the two machines with the same dimensionless
parameters. We will obtain edge profiles both at threshold and in the steady
H-mode period. AUG will then try to match the
dimensionless parameters (nu*,beta, rho*) of these discharges.

Plan:

1) Obtain suitable shape, plasma parameters. Start with shape from shot
1010605016. Raise Ip to 1.0 MA, keep Bt at 5.3 T. L-mode nel=1.1e20 m-2.
Once plasma is obtained, adjust shape to get a better match to AUG pulse 14265.
This will involve increasing the inner gap and the radius of the x-point.
RF should use these shots (3-4?) to tune and condition;
For the last shot we would like a power ramp up to >~2 MW to get the
threshold power, and both L and H-mode tunes.

2) High power EDAs. Use square wave RF pulse at Ptot=2.5 MW using D and E at
80 MHz (more if we can get it). Measure pedestals, and fluctuations.
Tune J-port at low power on these.


3) Add power from J-port (70 MHz), at maximum available power. This will be
off-axis, which is non-optimal, but should help to raise pedestal temperature.


4) Increase density. A dimensionless match to the best AUG 'grassy ELM' shots
would correspond to a line integrated density of 4.7e20, higher than our usual
range. Increase starting density, and probably puff gas into EDA, to see how
high we can get and still maintain a decent, steady H-mode (and couple enough
power). ECE will probably be cut off, so good ETS data are essential.
Again, use max available power without and with J-port.

4) Once the 'high density' H-mode has been characterized, use a slow power
ramp to determine the corresponding threshold power and edge parameters.
PHYSICS_OPERATOR Jul 19 2001 08:36AM Ian Hutchinson MP 287 AUG Similarity

Cold start.
Start PCS.
Import segment 2 from USER10:[WOLFE.MDS.SHOTS.HYBRID.PCS]PCS_1010706000
Load.
SL_SUMMARY Jul 07 2004 03:49PM To Be Determined #41 of 43 OPS
Date: 20-JUL-2001 15:03 Expires: 3-AUG-2001 15:03
From: AMAZON::HUBBARD
Subj: Run Summary 1010719 (ASDEX Upgrade Similarity)

Physics Run Summary for 1010719, MP 287 Asdex H-mode similarity experiment

Session Leader: Amanda Hubbard
Physics Operator: Ian Hutchinson
RF Operators: S. Wukitch, Y. Lin

Goal: To make high density, high power EDA H-modes in a shape identical to
that in ASDEX-Upgrade 'Type II ELM' discharges. This regime,
which was only recently obtained on AUG, appears rather similar to that
obtained on C-Mod when power is increased into EDA H-modes. At reduced powers,
AUG sometimes sees a 'quasi-coherent' mode. We would like to see if the same
behaviour is observed on the two machines with the same dimensionless
parameters. We will obtain edge profiles both at threshold and in the steady
H-mode period. AUG will then try to match the
dimensionless parameters (nu*,beta, rho*) of these discharges.

Plan:

1) Obtain suitable shape, plasma parameters. Start with shape from shot
1010605016. Raise Ip to 1.0 MA, keep Bt at 5.3 T. L-mode nel=1.1e20 m-2.

Once plasma is obtained, adjust shape to get a better match to AUG pulse 14265.
This will involve increasing the inner gap and the radius of the x-point.
RF should use these shots (3-4?) to tune and condition;
For the last shot we would like a power ramp up to >~2 MW to get the
threshold power, and both L and H-mode tunes.

2) High power EDAs. Use square wave RF pulse at Ptot=2.5 MW using D and E at
80 MHz (more if we can get it). Measure pedestals, and fluctuations.
Tune J-port at low power on these.


3) Add power from J-port (70 MHz), at maximum available power. This will be
off-axis, which is non-optimal, but should help to raise pedestal temperature.

4) Increase density. A dimensionless match to the best AUG 'grassy ELM' shots
would correspond to a line integrated density of 4.7e20, higher than our usual
range. Increase starting density, and probably puff gas into EDA, to see how
high we can get and still maintain a decent, steady H-mode (and couple enough
power). ECE will probably be cut off, so good ETS data are essential.
Again, use max available power without and with J-port.

4) Once the 'high density' H-mode has been characterized, use a slow power
ramp to determine the corresponding threshold power and edge parameters.

Results:

We had limited success with this run, primarily due to poor machine conditions.
This was probably a result of the recent vent, combined with the fact that we
were running non-standard shapes, and thus putting power on different vessel
surfaces. This led to impurity injections and, most critically, to a high
hydrogen fraction (up to 20%) which limited the RF power absorption; H/D
typically increases during each discharge, with Pabs decreasing.

The shape development part of the run went quite smoothly, and we
did get shots which were a very close match to ASDEX Upgrade shapes (see
physics operator summary for details of changes made). These had elongation
close to our vertical stability limits (k~1.73), and were close to double null,
which may have caused some interaction with upper vessel surfaces, and possibly
also increased H-mode thresholds. The last AUG shaped shot, 1010719020, is a
good example (Delta_u=0.34, delta_l= 0.47)

J-port was not available for the run after all, so we ran with typically 2.3
MW at 80 MHz from D and E port antennas. However, the low absorption means
that the effective power was actually much lower, especially late in the pulse.
We were unable to get any H-modes which had a steady, EDA character. Many were
ELM-free, with strongly increasing impurities. (eg. shot 2, 14). Others, with
lower power and higher radiation, had periodic behaviour typical of Type III
ELMs; the pedestal was very cold (eg. shots 5,13). On shots 9 and 11 we ramped
the RF up slowly to get threshold data, and found it was over the 2.3 MW
injected); this is very high for these C-Mod conditions. Making the discharge
more 'single null' had little effect (shot 12). Lowering the target density
from nel= 0.9 to 0.7e20 m-2, while it had minimal effect on nebar at the RF
onset (1.35-1.4e20m-3 in both cases), resulted in much lower neutral pressure
anda threshold of Prf=1.13 MW (shot 13). This may be a good point for threshold
comparison, though it was rather early in the ramp. Shot 14 had full RF power
at this density, and resulted in ELM-free H-modes.

In an attempts to favour the EDA regime, Ip was lowered from 1.0 to 0.9 MA from
shot 15 on. This raised q95 to 4.2. The rates of density rise did decrease
slightly, though not an obvious EDA regime. Shot 16 had hints of a weak
quasi-coherent
mode on PCI. Shot 17 was colder and more ELMy. From shot 19 Bt was raised
from 5.3 T to 5.6 T, raising q95 still further and a better match to the AUG
target. This proved more difficult for the RF to match, for reasons not well
understood at least by me, and power was not as steady as the rest of the day.
The density did appear to be getting more steady, and QC modes characteristic
of EDA were seen on PCI. Shot 21, about 0.75-0.8 secs, may be a good time for
pedestal analysis. For shot 22, we went back to a standard shape, 800 kA shot
to check we could get EDA there. We did, but it quickly cooled and reverted to
Type III ELMs as H/D rose.

In summary, as expected, it was more difficult to get steady H-modes in the
lower triangularity ASDEX-Upgrade shape. However, the poor machine conditions
and low absorbed power undoubtedly were a major impediment, and there were
indications we were getting close. There was insufficient power to try raising
the density. Since the discharge development has been successfully completed,
we would very much like to revisit this experiment on a day with better vessel
conditions and all three RF antennas available.

Shot Details:

----------------------------------------------------------------------------
1010719001 hubbard SESSION_LEADER Jul 19 2001 8:54:52:166AM
. . . . . . . . . . . . . . . . . . . .
First shot had 5.6 T, 2 MW RF with several trips. 3 H-modes, very ELM-free.
----------------------------------------------------------------------------
1010719002 hubbard SESSION_LEADER Jul 19 2001 9:13:07:103AM
. . . . . . . . . . . . . . . . . . . .
Bt= 5.35 T, 2 MW RF. 3 H-modes, very ELM-free. 3 H-modes, ended by big
injections.

Disrupts 1.3 secs.

H/D getting to 10%, and second half of flat-top is L-mode, indicating poor
heating and/or high radiation.
For next shot, increase outer gap.
-----------------------------------------------------------------------------
1010719005 hubbard SESSION_LEADER Jul 19 2001 10:35:02:120AM
. . . . . . . . . . . . . . . . . . . .
Better; makes it to 1.47 secs. Three H-modes, and the third is quite steady.
However, H/D at this point is 20%, radiation is high and net power therefore
presumably very low.

Pedestal Te ~ 200 eV; may be in an intermittent ELMy/EDA regime.

For next shot, try to increase RF power. Asked Stu Zweben to delay D2 puffing
to 1.4 secs.
-----------------------------------------------------------------------------
1010719006 hubbard SESSION_LEADER Jul 19 2001 10:36:52:666AM
. . . . . . . . . . . . . . . . . . . .
Disrupted 0.82 seconds. Two H-modes, not EDA. Both end due to rapid increase
of Prad.

H/D still very high, though core heating seems OK in this early period.

Next shot: ramp RF power slowly to get threshold point, and also see if
injections are related to
Prf.
-----------------------------------------------------------------------------
1010719008 hubbard SESSION_LEADER Jul 19 2001 11:01:57:353AM
. . . . . . . . . . . . . . . . . . . .
Disrupted 0.92 seconds; vertical instability, no big injections.

RF ramp got to 1.2 MW, stayed in L-mode. H/D~8%.

Will increase outer gap a bit to try to improve stability, try ramp again.
-----------------------------------------------------------------------------
1010719009 hubbard SESSION_LEADER Jul 19 2001 11:49:21:743AM
. . . . . . . . . . . . . . . . . . . .
Made it all the way to rampdown, but with a huge injection 0.75 secs. RF ramps
to 2.3 MW, but
stays in L-mode. Why??

ECE valve was closed.

Nice shape match, esp earlier in flat-top
-----------------------------------------------------------------------------
1010719011 hubbard SESSION_LEADER Jul 19 2001 12:20:25:196PM
. . . . . . . . . . . . . . . . . . . .
Made it to 1.4 seconds. RF ramps 1.0 to 2.3 MW, as requested. Plasma STILL
stays in L-mode. Why??
Got good central heating, Te0 1.3-2.6 keV.

Possibly we are too close to double-null; will change upper x-pt for next shot
and repeat.
-----------------------------------------------------------------------------
1010719012 hubbard SESSION_LEADER Jul 19 2001 12:45:39:916PM
. . . . . . . . . . . . . . . . . . . .
VERY similar to shot 11.
Made it to 1.4 seconds. RF ramps 1.0 to 2.3 MW, as requested. Plasma STILL
stays in L-mode. Why??


Try backing off on density, replace ~200 kW of D-port power by E-port in case
it is contributing to the
injection.
-----------------------------------------------------------------------------
1010719013 hubbard SESSION_LEADER Jul 19 2001 1:09:58:650PM
. . . . . . . . . . . . . . . . . . . .
Lowering density got us into H-mode, at 0.665 secs, 1.13 MW. H-mode was very
ELMy; low pedestal
temperatures. RF ramped up slowly as requested, H/D ramped up to 0.2 (as NOT
requested).

Next shot try full RF power right away.
-----------------------------------------------------------------------------
1010719014 hubbard SESSION_LEADER Jul 19 2001 1:21:51:980PM
. . . . . . . . . . . . . . . . . . . .
Got 2.3 MW, only a few minor trips. This time we had a series of more ELM-free
H-modes, with
accumulating impurities and radiation. Not a pretty sight. H/D is up to 0.18!

Next shot, lower Ip to 0.9 MW in an attempt to get EDA conditions.
-----------------------------------------------------------------------------
1010719015 hubbard SESSION_LEADER Jul 19 2001 2:08:46:020PM
. . . . . . . . . . . . . . . . . . . .
Reducing Ip to 900 kA increased q95 to ~4.2. Got a somewhat longer, steadier
H-mode;
not quite EDA I think. A few RF trips; retune and repeat.

-----------------------------------------------------------------------------
1010719016 hubbard SESSION_LEADER Jul 19 2001 2:16:33:593PM
. . . . . . . . . . . . . . . . . . . .
Steady RF on this one, 2.2 MW. For some reason H-modes are shorter, accumulate
more ne and
impurities. Next shot, increase nel ~ 10%.
Nel was 0.75-1.84x10^20 m-2 on this one.

Appears to be a weak quasicoherent mode partway through these H-modes (as seen
on PCI).
Frequency is lower than usual.
-----------------------------------------------------------------------------
1010719017 hubbard SESSION_LEADER Jul 19 2001 2:38:33:220PM
. . . . . . . . . . . . . . . . . . . .
At slightly higher nel 0.87-1.9x10^20 m-2, got into a series of ELMy periods.
Temperatures, edge and
core, drop dramatically through RF pulse, presumably due to high H/D.

For the next shot, raise Bt to 5.6 T, as in the original run plan, thus raising
q95.
-----------------------------------------------------------------------------
1010719019 hubbard SESSION_LEADER Jul 19 2001 3:09:55:533PM
. . . . . . . . . . . . . . . . . . . .
Bt 5.6, q95=4.3. two H-modes, but really not at all EDAish. ne, Prad rise
and erode Tedge.
RF had some trips; will retune for the new field and try again.

Also increasing outer gap slightly.
-----------------------------------------------------------------------------
1010719020 hubbard SESSION_LEADER Jul 19 2001 3:43:27:930PM
. . . . . . . . . . . . . . . . . . . .
Rather similar. RF finds big loading changes ~0.8-0.9. Retune, lower power
and try again.
-----------------------------------------------------------------------------
1010719021 hubbard SESSION_LEADER Jul 19 2001 3:52:12:270PM
. . . . . . . . . . . . . . . . . . . .
Still a lot of RF trips. Two H-modes. The first has a steadier density,
though conditions never get
quite stationary. Period 0.75-0.8 secs is fairly steady, may be good to look
at pedestal parameters.
QC mode appears during this window too (on PCI)

nel1.6e20 m-2, nebar=2.8e20 m-3, TE,ped 340 ev(Thomson) (also Te7, ECE), te_95
=400 eV,
ne_95 1.8e20.

All profiles, parameters need checking!

For next shot, load a standard C-Mod shape from 1010716004, 780 kA, 5.36 T, to
see if we get back
a good EDA.

-----------------------------------------------------------------------------
1010719022 hubbard SESSION_LEADER Jul 19 2001 4:10:21:470PM
. . . . . . . . . . . . . . . . . . . .
reload of 1010716004 (780 kA, standard shape) does give EDA, at least to ~0.8
seconds. Edge and core
temps then decrease, presumably due to H/D increase (8-12 %), and discharge
gets ELMy.
PCI sees 'classic QC mode'

~1.9 MW RF, better loading.
-
PO_SUMMARY Jul 07 2004 04:37PM To Be Determined Physop Summary for 19 Jul 2001

MP 287 AUG Similarity.

PO Hutch
SL Hubbard.


Summary
_______

Shapes that are an excellent match to the scaled AUG shape were
obtained (e.g. 21) and many were run. A comparison plot is in
user10:[hutch.ps]aug_match.ps. They are close to double null;
although a range of three sseps was run without obvious effect on the
plasma character. No solid EDA H-modes were obtained. The H/D was high
and rose strongly with RF in the early part of the day. Later on, the
rises seemed less significant, but in all cases the H/D was above 10%
during much of the RF pulse. Heating was clearly inefficient in many
cases. In some others heating was ok even at high H/D.

The early part of the day was plagued with injections. Many appeared
to be caused by visible sparks on the upper left corner of D-antenna.
Some others were not RF induced. As the day wore on, these problems
were less severe, and the plasma ran reasonably reliably.

These shapes are fairly close to stability limits. One or two VDEs were
experienced. The chopper V was set to 150 to 200 instead of the usual 0
to lower the operating average current to a position closer to the center
of its range. This adjustment seemed to be a significant improvement in
that it allowed operation with an elongation that gave rise to noisy chopper
behaviour without leading to saturations and subsequent VDE.

A manual gas puff during the RF did not significantly improve the
operation, but also did not seem to give much impact on the RF coupling
despite a x2 rise in main chamber neutral pressure.

It appears to be confirmed that the lower triangularity that is needed to
match AUG makes it harder to get into EDA. The high H level was also
definitely a handicap.


Scorecard.
__________

Shot,Duration(s),Ipmax(MA) Shot,Duration(s),Ipmax
1 1.910 1.005 2 1.322 1.059
3 0.745 1.012 4 0.934 1.002
5 1.533 0.992 6 0.816 0.999
7 0.000 0.031 8 0.939 1.062
9 1.889 0.992 10 0.000 0.034
11 1.443 1.012 12 1.456 1.023
13 1.925 0.999 14 1.671 1.005
15 1.905 0.911 16 1.912 0.909
17 1.895 0.908 18 0.000 0.024
19 1.920 0.914 20 1.905 0.914
21 1.928 0.914 22 1.921 0.810

Finished summary for 1010719 Total of 22 shots.
22 shots. 19 plasmas. 1 fizzles. 2 PS duds.


Details
_______

1010719xxx hutch PHYSICS_OPERATOR Jul 19 2001 8:36:56:150AM
. . . . . . . . . . . . . . . . . . . .
MP 287 AUG Similarity

Cold start.
Start PCS.
Import segment 2 from USER10:[WOLFE.MDS.SHOTS.HYBRID.PCS]PCS_1010706000
Load.
----------------------------------------------------------------------------
1010719001 hutch PHYSICS_OPERATOR Jul 19 2001 8:56:17:993AM
. . . . . . . . . . . . . . . . . . . .
Plasma. 3 ELM-free H-modes and a ramp-down. RF a ragged 2MW max.


zxu to 0 from +2cm
Bt to 5.4T (150kA)
----------------------------------------------------------------------------
1010719002 hutch PHYSICS_OPERATOR Jul 19 2001 9:13:21:963AM
. . . . . . . . . . . . . . . . . . . .
Plasma disrupts at 1.3s seems to be an injection.
RF antenna injections earlier in the shot cause H-mode drop outs.

Move rcur in 2-3mm. Lower clearin 0-1mm.
----------------------------------------------------------------------------
1010719003 hutch PHYSICS_OPERATOR Jul 19 2001 9:34:30:933AM
. . . . . . . . . . . . . . . . . . . .
Plasma disrupts at 0.73s. Big injection. Appears on wide angle at D.

Take 1 ms off the fill puff to compensate for the DNB.
Add 2mm to rxl.
----------------------------------------------------------------------------
1010719004 hutch PHYSICS_OPERATOR Jul 19 2001 9:55:15:370AM
. . . . . . . . . . . . . . . . . . . .
Plasma disrupts at 0.92s.
Multiple injections starting at 0.56s. Which is before the
RF turns on.

Install a ramp in rxl to try to avoid the injections.
Raise nl04 at 0.2ms to try to keep puff on.
----------------------------------------------------------------------------
1010719005 hutch PHYSICS_OPERATOR Jul 19 2001 10:20:30:026AM
. . . . . . . . . . . . . . . . . . . .
Plasma. Disrupts at 1.52s. H to D ratio is high.

Repeat
----------------------------------------------------------------------------
1010719006 hutch PHYSICS_OPERATOR Jul 19 2001 10:38:06:526AM
. . . . . . . . . . . . . . . . . . . .
Plasma. Disrupts at .62s.

Remove the big rxl jerk in ramp-down.
Also ramp to the lower triangularity quicker. By .9s.
----------------------------------------------------------------------------
1010719007 hutch PHYSICS_OPERATOR Jul 19 2001 10:49:54:806AM
. . . . . . . . . . . . . . . . . . . .
No TF. Dud.
----------------------------------------------------------------------------
1010719008 hutch PHYSICS_OPERATOR Jul 19 2001 11:25:21:853AM
. . . . . . . . . . . . . . . . . . . .
Plasma. Disrupts at 0.93s. VDE. Chopper working hard.

Reduce clearin by 2mm.
Put chopper V to +150V during shot to change offset
and try to give us more headroom on vertical control.
----------------------------------------------------------------------------
1010719009 hutch PHYSICS_OPERATOR Jul 19 2001 11:47:15:823AM
. . . . . . . . . . . . . . . . . . . .
Plasma. Survived to ramp-down.

Chopper average current was lowered as anticipated and this seems
to be a better place to run.
RF stayed on. No H-mode.

Repeat
----------------------------------------------------------------------------
1010719010 hutch PHYSICS_OPERATOR Jul 19 2001 12:05:42:963PM
. . . . . . . . . . . . . . . . . . . .
Fizzle.

Take 0.5ms off the gas fill puff.
----------------------------------------------------------------------------
1010719011 hutch PHYSICS_OPERATOR Jul 19 2001 12:28:12:823PM
. . . . . . . . . . . . . . . . . . . .
Plasma disrupts at 1.4s. Injection. No H-mode.

zxu to .01 from 0, to back away from double null and
see if we can get H-mode back
----------------------------------------------------------------------------
1010719012 hutch PHYSICS_OPERATOR Jul 19 2001 12:48:03:806PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Disrupts at 1.45s. These injections seem to occur at D antenna.

nl04 to 0.9 from 1.1
----------------------------------------------------------------------------
1010719013 hutch PHYSICS_OPERATOR Jul 19 2001 1:10:14:790PM
. . . . . . . . . . . . . . . . . . . .
Plasma. H-modes. No disruption.

Repeat.
----------------------------------------------------------------------------
1010719014 hutch PHYSICS_OPERATOR Jul 19 2001 1:31:57:056PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Similar to previous. Disruption in ramp down. Horrid
ragged H-modes.

Ip to .9MA.
----------------------------------------------------------------------------
1010719015 hutch PHYSICS_OPERATOR Jul 19 2001 1:55:33:776PM
. . . . . . . . . . . . . . . . . . . .
Plasma. H/D peaks at 17%.

Chopper V ramps to 200 at 1.3s
----------------------------------------------------------------------------
1010719016 hutch PHYSICS_OPERATOR Jul 19 2001 2:23:02:633PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Similar to previous.

Raise early nl04 and target to .95.
Put a V gas 3 puff of 50V at .75 to .85s.
----------------------------------------------------------------------------
1010719017 hutch PHYSICS_OPERATOR Jul 19 2001 2:38:23:720PM
. . . . . . . . . . . . . . . . . . . .
Plasma. Radiative L/H sustained phase.

TF current to 156kA.
Back off slightly on nl04 during .5s.
Manual V pulse to 100V.
----------------------------------------------------------------------------
1010719018 hutch PHYSICS_OPERATOR Jul 19 2001 2:53:27:166PM
. . . . . . . . . . . . . . . . . . . .
Dud. No EF4.
----------------------------------------------------------------------------
1010719019 hutch PHYSICS_OPERATOR Jul 19 2001 3:16:23:890PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

Move in Rcur by 2mm.
Turn off nl04 gain at .6s.
----------------------------------------------------------------------------
1010719020 hutch PHYSICS_OPERATOR Jul 19 2001 3:38:09:733PM
. . . . . . . . . . . . . . . . . . . .
Plasma. 3 H-modes. RF tripping. Survives the narrower shape.

RF reports a big drop in load during the time the neutral pressure
is rising. Hence remove the gas puff.
----------------------------------------------------------------------------
1010719021 hutch PHYSICS_OPERATOR Jul 19 2001 4:03:49:336PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

Import segment 2 from 1010716004 a standard EDA shot at .8MA.
The ramp in antenna loading is still strong, apparently. Hence
we can probably rule out the gas puff as the cause.
----------------------------------------------------------------------------
1010719022 hutch PHYSICS_OPERATOR Jul 19 2001 4:04:45:336PM
. . . . . . . . . . . . . . . . . . . .
Plasma. EDA just. But not pretty.

TCI Jul 19 2001 07:55AM Rick Murray TCI signal levels look good this morning.