Alcator C-Mod Run 1020910 Information

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Miniproposals
Miniproposal:314
Date Filed: 8/5/2002
Title:Evaluate BTOR-sweep method of measuring temperature gradientscale length.
First Author:David Mikkelsen
Session Leader:Amanda Hubbard (shots 1-28)

Operators
Session leader(s):Amanda Hubbard
Physics operator(s):Robert Granetz
Engineering operator(s):Bill Cochran,Bill Parkin,Bill Byford

Engineering Operator Run Comment
MP 314 Btor ramps to measure dTe/dr. Hubbard/Granetz.

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:30:443PM
Author: To Be Determined
Session Leader's summary for 1020910
Session Leader: Amanda Hubbard
Physics Operator: Bob Granetz
Eng. Operator: Bill Byford

MP 314 (David Mikkelsen, in absentia)
Evaluate BT sweep method of LTe

Aim:
1) Establish reliability and uncertainty of measuring Lte using Bt sweeps, in
ohmic plasmas.
2) Measure q dependence of LTe, using Ip scan.

A rough run plan:
1) Set up a 1 MA, 5.4 T discharge, with 'normal' diverted shape and nebar
~2.e20 (nel ~1.2?).
A suitable starting shot may be 1020828026. Repeat discharges until steady
conditions are reached (which means good ne control, no impurity injections
or accumulation, and modest (30%?) radiation.) No disruptions, natch! Given
we just had a vaccuum break, this may take several shots.

2). Take 1-2 discharges with a big, slow TF ramp 5.0-6.0 T. The purpose is
to quantify the ECE position discrapancy (useful for analysing this and other
expts).

3) Start Dave's run sequence from MP 314, with the 1 MA set of shots. (at
least three, may want to vary sweep rate).

4) Repeat at 0.5 MA.

5) Repeat at 1.3 (not 1.5!) MA.

If we get this far, keep following Dave's shot sequence (ie density scan).

Results:
As expected, given this was the first run after a machine vent, several shots
were needed to re-establish full length discharges. Shots 1-3 were short and
disruptive, 4 was a full length 800 kA discharge, and 7 and 8 were again
radiative and disruptive. Raising Ip to 1 MA on shot 9 helped to get over the
radiation problem, and we entered a pattern of alternating fizzles and full
length plasmas. Shot 11 had the required higher density, nebar=2x 10^20 m-3.

All of the discharges had fairly high radiation (typically 700 kW on 2pi-foil
bolo) and had modest but clear and steady decreases in Te, and stored energy,
throughout the flat top. These conditions are thus not truly suitable to test
the limitations of the Bt sweep method for Lte determination. However, we did
go ahead and try several shots with Bt variation.

Shots 14 and 16 had large, slow variations in Btor, 4.6 to 5.8 T on shot 16.
During this sweep, various GPC channels in the gradient region overlaid
remarkably well, demonstrating that Te(R) is fairly insensitive to B (one of
the main assumptions of the method). The sweeps also clearly showed that the
apparent position of the edge, based on GPC position calculations, is well
inside Rsep. A shift of 22 mm gave good alignment with edge TS (actually on
shot 27, which had the best ETS signals) and reasonable Tsep~70 eV). The
determination of the error in the magnetic axis was less clear than I had
hoped, since the variation of sawtooth amplitude across the core region is
rather weak in ohmic plasmas. Various estimates, based on inversion radius and
internal MHD, range from 1.9 to 2.3 cm. (as an aside, a clearer determination
was obtained with RF heating on 1020911, and gave a shift of 1.3 cm)

Shot 22 returned to steady Te to check the constancy of the discharge (still
not great). Shots 22, 25, and 27 were the only ones to test the small Bt
sweeps called for in the main part of the MP. Nominal Sweep was 5.4-5.6 T.
On shot 22, triangular ramps with 80 ms period were programmed. The response
was too slow and actual sweep was only 5.4-5.4 T (less in backsweep). For shot
25, we programmed 'steps' in Bt which gave close to the intended sweep.
However, engineers reported that this caused increases in alternator vibration.
Such TF waveforms have been used many times in past campaigns for pedestal
measurements. Either we are now looking more closely at the alternator
signals, or there has been a change in the alternator that makes it more
sensitive; this should obviously be investigated! For shot 27, we slowed down
the ramps considerably, taking 250 ms to scan 0.2 T. This gave good gradient
measurements. Comparing the three shots should allow Dave to determine how
much sweep is really needed. A 250 ms sweep time may limit the utility of the
method for RF-heated or H-mode discharges, which rarely stay completely steady
for this duration.

Since we did not start the parameter scan part of the MP, it should be
revisited once machine conditions improve and we can get truly steady Te in
ohmic plasmas.


Physics Operator Summaries
Entered: Jul 7 2004 04:37:16:083PM
Author: To Be Determined
Physics operator summary for run 1020910 (Tuesday):

MP 314: Btor ramps to measure dTe/dr

Session leader: A. Hubbard
Physics operator: R. Granetz
Engineer in charge: W. Cochran, Bill Byford, Bill Parkin

Summary: Sort of a so-so day. It was partly a recovery day from this weekend's
vent, yet we managed to get reasonable data for the first part of
MP 314. There are hints on the RGA that we may still have a vacuum
leak. After some short disruptive shots early on, we settled down
to a 50-50 mix of 1 MA plasmas and fizzles. A number of shots had
varying degrees of Btor ramps, and the resulting GPC data looks
very good (see Amanda's run summary), but it's only a beginning. We
had to slow the Btor waggles down (to less than what we used to do
for edge Te scans) in order to keep things quiet in the alternator
house.

It would be really nice if we could get the ratiomatic gauge working
again...otherwise the physop is working in the dark as far as
diagnosing fizzle problems.

Scorecard: 14 plasmas
13 fizzles
0 duds
0 test
1 aborted and/or screwed up by computer problems
----------
28 total

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

Engineering setup for Tuesday 10 Sept 2002

MP 314: Btor ramps to measure dTe/dr

Session leader: A. Hubbard
Physics operator: R. Granetz

ECDC overnight in D2 at 2e-4 Torr, stopping by 07:00.
Bake at 60 C overnight as well.
Set up for possible ECDC in D2 between shots.

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

Power systems the same as shot 1020828026 (1.0 MA, 5.3 T, lower single null)

Gas setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar Hybrid enabled (PG1)
fill B-side upper with 10 psi D2 Hybrid DISABLED (PG2) (for ECDC)
fill C-side with 30 psi D2 Hybrid enabled (PG3)
leave J-Bottom as is Hybrid DISABLED (PG5)

Enable the following gate valves, assuming no vacuum problems:
ECE, VUV
Do NOT enable the DNB gate valve yet.

-------------------------------------------------------------------------------
RF Setup: All 4 transmitters in Remote before access-control is enabled.

-------------------------------------------------------------------------------
Run Plan:

Measure local dTe/dr by adding small ramps to Btor. Start with shot 1020828026
(1.0 MA, 5.3 T, 2.0e20 m-3, normal shape), but bump up Btor to 5.4 T (constant)
Then add the prescribed Btor waggles. If there's time, re-run at 0.5 MA,
the 1.3 MA, then at ne=1.0e20 m-3.

Late-breaking addition to plan: after the first shot (with constant Btor),
Amanda requests that we do 1-2 shots with a large, slow Btor ramp (5 -> 6 T)
to help resolve the issues surrounding the Btor calibration and ECE channel
locations.

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

ECDC was done overnight, as well as a bake at 60 C.

Hybrid coldstart done; no errors found

Loaded PCS from shot 1020828026 (all segments). Tweak Btor to 5.4 T
(rather than 5.3 T), tweak nl_04 to 1.2e20 m-2 (2e20 m-3), reduce
pre-fill puff to 23 ms.

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

Due to high levels of nitrogen, argon, etcetera, and the dire predictions of
the peanut gallery, I've reduced the plasma current to 0.8 MA for the
beginning of the run.

Shot 01 -- Plasma, but only lasted until 0.17 s. Startup looks okay, but
the g-side ratiomatic isn't working. No mflux traces either.

Next shot: reduce pre-fill by 2 ms.

Shot 02 -- Plasma...another short one.

Next shot: reduce nl_04 to 0.8e20 m-2. Also tweak Btor a tiny
amount, although we've pretty much de facto abandoned the run
until we recover from the recent vent.

Shot 03 -- Plasma. Disrupted at 0.24 s.

Next shot: reduce nl_04 to 0.6e20 m-2 and slow it down, reduce
pre-programmed gas puff in segment 2 as well.

Shot 04 -- Plasma. Good shot...complete rampdown. nl_04=0.65e20 m-2; no
hard x-rays. Btor=5.39 T. H/D=0.35.

Next shot: increase nl_04 to 0.9e20 m-2

Shot 05 -- Fizzle.

Next shot: no changes.

Shot 06 -- Aborted. Shot cycle problem.

Next shot: try again. Disable argon puff (B-side-lower).

Shot 07 -- Plasma. Disrupted at t=0.54 s, after getting very resistive.
However, the magnetics CPCI's all failed...each channel only
has one data point. Josh is looking at it.

Josh has requested that I power cycle the CPCI's, which I did.

Next shot: no changes.

Shot 08 -- Plasma. Disrupted at t=0.56 s, after getting resistive. The
magnetics CPCI are working again.

Next shot: back off on the density a little, and raise Ip to 1.0 MA.

Shot 09 -- Plasma. 1.0 MA. Nearly full length. nl_04=0.85e20 m-2
(nebar=1.4e20 m-3), 5.4 T.

Next shot: try again to raise nl_04 to 1.0e20 m-2, now at 1 MA.

Shot 10 -- Fizzle. Since I don't have any pressure measurement, I can't
tell if the pre-fill pressure is different on these fizzles.

Next shot: no changes

Shot 11 -- Plasma. 1.0 MA, nice shot. nl_04=1.0-1.05e20 m-2.

Next shot: raise nl_04 to 1.1e20 m-2.

Shot 12 -- Fizzle. We seem to be in an alternating pattern...not unusual for
a recovery run.

Next shot: no PCS changes

Shot 13 -- Fizzle.

Next shot: reduce pre-fill by 1 ms. Add a TF ramp to do the
Btor = 5 -> 6 T scan. Raise current limit on TF to 175 kA.
Inform alternator crew of impending TF waggle. Also, enable the
argon valve.

Shot 14 -- Plasma. Good shot. 1 MA. Btor scanned from 5.1 -> 5.85 T.
nl_04=1.15e20 m-2, which is just about what we wanted. Not much
change in Te0 though.

Next shot: try to pull the density down faster after t=1.5 s.
Increase the range of the Btor ramp from 4.5 -> 6.1 T, adjusting
times appropriately to keep ramp rates within allowed limit
of 75 kA/s.

I had to leave for a dentist appt. Steve Wolfe is taking over now.

Shot 15 -- Fizzle.

Shot 16 -- Plasma. Large Btor ramp. Some change seen on Te0.

Shot 17 -- Fizzle.

Shot 18 -- Fizzle.

Shot 19 -- Fizzle.

Next shot: Steve re-loaded the startup segment from shot 11.

Shot 20 -- Plasma. Good shot. 1 MA, 5.4 T (constant), nebar=2.0e20 m-3.
Lots of hard x-rays.

Next shot: put in Btor waggles, as prescribed in updated MP,
lengthen Ip flattop to t=1.69 s, increase early gas puffing.

Shot 21 -- Fizzle.

Next shot: reduce pre-fill by 2 ms.

Shot 22 -- Plasma. Good shot. 1 MA, with small Btor wiggles of about half
the amplitude that we wanted. dI_tf/dt is also about half the
limit as well. Hard x-rays are gone. H/D=0.3-0.4 .

Next shot: put in square steps for the Btor waggles, increase
argon puff to 50 ms.

Shot 23 -- Fizzle.

Next shot: no changes

Shot 24 -- Fizzle. Two in a row. Current is rising a little faster than
on shot 22.

Next shot: increase pre-fill puff by 2 ms.

Shot 25 -- Plasma. Good shot. 1 MA with Btor wiggles. Apparently the
square programming gave too much noise in the alternator house.

Next shot: reprogram the TF waggles as slower ramps. Move
the TF invert time to 1.7 s. Add 1 ms to pre-fill puff.

Shot 26 -- Fizzle. Ip rise is definitely slower...maybe too slow.

Next shot: subtract 1 ms from pre-fill puff

Shot 27 -- Plasma. Good shot. 1 MA with Btor waggles. Final Btor flattop
at 5.6 T was way too short.

Next shot: more adjustment of the Btor waggles to get the ramps
to turn out more like we want. No changes to the startup.

Shot 28 -- Fizzle. Darn!

End of run.

Session Leader Comments
Sep 10 2002 09:30:32:813AMAmanda HubbardMP 314 (David Mikkelsen, in absentia)
Evaluate BT sweep method of LTe

Aim:
1) Establish reliability and uncertainty of measuring Lte using Bt sweeps, in ohmic plasmas.
2) Measure q dependence of LTe, using Ip scan.

A rough run plan:
1) Set up a 1 MA, 5.4 T discharge, with 'normal' diverted shape and nebar~2.e20 (nel ~1.2?).
A suitable starting shot may be 1020828026. Repeat discharges until steady conditions are
reached (which means good ne control, no impurity injections or accumulation, and
modest (30%?) radiation.) No disruptions, natch! Given we just had a vaccuum break, this may take
several shots.

2). Take 1-2 discharges with a big, slow TF ramp 5.0-6.0 T. The purpose is to quantify the ECE
position discrapancy (useful for analysing this and other expts).

3) Start Dave's run sequence from MP 314, with the 1 MA set of shots. (at least three, may want to vary
sweep rate).

4) Repeat at 0.5 MA.

5) Repeat at 1.3 (not 1.5!) MA.

If we get this far, keep following Dave's shot sequence (ie density scan).
Sep 10 2002 12:46:20:990PM1020910011Amanda HubbardNice shot, getting close to what we need for the MP.

Te(0) is still drooping slightly during the discharge (not as much as W MHD).
Outer Te's dropping more.
nebar=1.9e20 m-3.
Sep 10 2002 01:53:42:700PM1020910014Amanda HubbardFor this shot, added a large Bt sweep, nominal 5 to 6 T, but actually 5.2-5.8.

The change in sawtooth amplitude is not as clear as hoped, when channels are close to center.
For next shot, start earlier and increase range (4.5-6 T), to pin down inversion radii.
Sep 10 2002 03:10:20:727PM1020910020Amanda HubbardBack to constant 5.4 T.
Fairly good, steady plasma. However, W(MHD) is dropping throughout the flat top
(43-32 kJ). Te's are also dropping. Nebar 1.9 to 2.1x 10^20 m-3.

Conditions are thus not ideal for Dave's LTe measurement, but we are going to go
ahead and try the Bt sweeps.
Sep 10 2002 03:37:02:330PM1020910020Amanda HubbardFirst attemp at the periodic Bt sweeps. They were smaller and slower than programmed.

Good shot, 45 to 36 kJ. Prad ~ 0.7 MW. nebar 1.9-2.0
Sep 10 2002 04:47:39:187PM1020910025Amanda HubbardMade the sweeps bigger (by programming in steps). This got us almost the ramp we wanted.
However, engineers are unhappy, so for the next attempt we will slow down to 250 ms per ramp,
which means starting earlier.

Physics Operator Comments
Sep 9 2002 02:20:35:850PMRobert GranetzRemember to re-install the magnetics integrator circuit boards and turn the circuit power supply
back on prior to beginning today's run!
Sep 9 2002 06:41:28:593PMRobert GranetzEngineering setup for Tuesday 10 Sept 2002

MP 314: Btor ramps to measure dTe/dr

Session leader: A. Hubbard
Physics operator: R. Granetz

ECDC overnight in D2 at 2e-4 Torr, stopping by 07:00.
Bake at 60 C overnight as well.
Set up for possible ECDC in D2 between shots.

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

Power systems the same as shot 1020828026 (1.0 MA, 5.3 T, lower single null)

Gas setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar Hybrid enabled (PG1)
fill B-side upper with 10 psi D2 Hybrid DISABLED (PG2) (for ECDC)
fill C-side with 30 psi D2 Hybrid enabled (PG3)
leave J-Bottom as is Hybrid DISABLED (PG5)

Enable the following gate valves, assuming no vacuum problems:
ECE, VUV
Do NOT enable the DNB gate valve yet.

-------------------------------------------------------------------------------
RF Setup: All 4 transmitters in Remote before access-control is enabled.

-------------------------------------------------------------------------------
Run Plan:

Measure local dTe/dr by adding small ramps to Btor. Start with shot 1020828026
(1.0 MA, 5.3 T, 2.0e20 m-3, normal shape), but bump up Btor to 5.4 T (constant)
Then add the prescribed Btor waggles. If there's time, re-run at 0.5 MA,
the 1.3 MA, then at ne=1.0e20 m-3.
Sep 10 2002 08:40:17:630AMRobert Granetz ECDC was done overnight, as well as a bake at 60 C.

Hybrid coldstart done; no errors found

Loaded PCS from shot 1020828026 (all segments). Tweak Btor to 5.4 T
(rather than 5.3 T), tweak nl_04 to 1.2e20 m-2 (2e20 m-3), reduce
pre-fill puff to 23 ms.
Sep 10 2002 08:54:01:960AMRobert GranetzLate-breaking addition to plan: after the first shot (with constant Btor),
Amanda requests that we do 1-2 shots with a large, slow Btor ramp (5 -> 6 T)
to help resolve the issues surrounding the Btor calibration and ECE channel
locations.
Sep 10 2002 09:44:04:930AMRobert GranetzDue to high levels of nitrogen, argon, etcetera, and the dire predictions of
the peanut gallery, I've reduced the plasma current to 0.8 MA for the
beginning of the run.
Sep 10 2002 10:06:17:963AM1020910001Robert GranetzShot 01 -- Plasma, but only lasted until 0.17 s. Startup looks okay, but
the g-side ratiomatic isn't working. No mflux traces either.

Next shot: reduce pre-fill by 2 ms.
Sep 10 2002 10:26:57:840AM1020910002Robert GranetzShot 02 -- Plasma...another short one.

Next shot: reduce nl_04 to 0.8e20 m-2. Also tweak Btor a tiny
amount, although we've pretty much de facto abandoned the run
until we recover from the recent vent.
Sep 10 2002 10:40:05:203AM1020910003Robert GranetzShot 03 -- Plasma. Disrupted at 0.24 s.

Next shot: reduce nl_04 to 0.6e20 m-2 and slow it down, reduce
pre-programmed gas puff in segment 2 as well.
Sep 10 2002 10:56:18:837AM1020910004Robert GranetzShot 04 -- Plasma. Good shot...complete rampdown. nl_04=0.65e20 m-2; no
hard x-rays. Btor=5.39 T. H/D=0.35.

Next shot: increase nl_04 to 0.9e20 m-2
Sep 10 2002 11:01:53:813AM1020910005Robert GranetzShot 05 -- Fizzle.

Next shot: no changes.
Sep 10 2002 11:29:21:543AM1020910006Robert GranetzShot 06 -- Aborted. Shot cycle problem.

Next shot: try again. Disable argon puff (B-side-lower).
Sep 10 2002 11:45:44:053AM1020910007Robert GranetzShot 07 -- Plasma. Disrupted at t=0.54 s, after getting very resistive.
However, the magnetics CPCI's all failed...each channel only
has one data point. Josh is looking at it.

Josh has requested that I power cycle the CPCI's, which I did.

Next shot: no changes.
Sep 10 2002 12:02:27:627PM1020910008Robert GranetzShot 08 -- Plasma. Disrupted at t=0.56 s, after getting resistive. The
magnetics CPCI are working again.

Next shot: back off on the density a little, and raise Ip to 1.0 MA.

Sep 10 2002 12:20:59:933PM1020910009Robert GranetzShot 09 -- Plasma. 1.0 MA. Nearly full length. nl_04=0.85e20 m-2
(nebar=1.4e20 m-3), 5.4 T.

Next shot: try again to raise nl_04 to 1.0e20 m-2, now at 1 MA.
Sep 10 2002 12:46:18:410PM1020910010Robert GranetzShot 10 -- Fizzle. Since I don't have any pressure measurement, I can't
tell if the pre-fill pressure is different on these fizzles.

Next shot: no changes
Sep 10 2002 12:45:58:847PM1020910011Robert GranetzShot 11 -- Plasma. 1.0 MA, nice shot. nl_04=1.0-1.05e20 m-2.

Next shot: raise nl_04 to 1.1e20 m-2.
Sep 10 2002 12:50:25:493PM1020910012Robert GranetzShot 12 -- Fizzle. We seem to be in an alternating pattern...not unusual for
a recovery run.

Next shot: no PCS changes
Sep 10 2002 01:13:09:857PM1020910013Robert GranetzShot 13 -- Fizzle.

Next shot: reduce pre-fill by 1 ms. Add a TF ramp to do the
Btor = 5 -> 6 T scan. Raise current limit on TF to 175 kA.
Inform alternator crew of impending TF waggle. Also, enable the
argon valve.
Sep 10 2002 01:38:00:333PM1020910014Robert GranetzShot 14 -- Plasma. Good shot. 1 MA. Btor scanned from 5.1 -> 5.85 T.
nl_04=1.15e20 m-2, which is just about what we wanted. Not much
change in Te0 though.

Next shot: try to pull the density down faster after t=1.5 s.
Increase the range of the Btor ramp from 4.5 -> 6.1 T, adjusting
times appropriately to keep ramp rates within allowed limit
of 75 kA/s.
Sep 10 2002 01:46:32:753PM1020910015Steve Wolfeshot#15: After this shot, wolfe taking over as physop for a
couple of hours.

fizzle. Thanks Bob!
next shot: ic_ef4 from -1320 to -1310
Sep 10 2002 02:05:48:720PM1020910016Steve Wolfeshot#16: ic_ef4 from -1320 to -1310
plasma, some hards early. disrupts at 1.72sec

Irby and Rosati have indicated that the signals to
watch on the alternator bearings scope are the spv2 and spv3 A and B
traces. They did show something on 1020830011

On shot 14, there was a small effect at the start of the first sweep,
not much after. On this shot, I don't see much going on on these.

next shot: back to constant 5.4 T, reload seg2 from shot11

Sep 10 2002 02:13:06:073PM1020910017Steve Wolfeshot#17: back to constant 5.4 T, reload seg2 from shot11;
no startup change, init at 3.6e-6Torr -- there still seems to be a leak.

fizzle.
next shot: ic_ef4 from -1310 to -1300; I want to get Bz0 back to positive,
then lower the puff

Sep 10 2002 02:27:57:393PM1020910018Steve Wolfeshot#18: back to constant 5.4 T, reload seg2 from shot11;
ic_ef4 from -1310 to -1300; I want to get Bz0 back to positive,
then lower the puff

another fizzle. current rise is fast, gets to 40kA by 12msec, then
hits outside. I may need to play with Ian's early rcur point.
change rcur[0.001] from .68 to .66
Sep 10 2002 02:37:01:110PM1020910019Steve Wolfeshot#19: back to constant 5.4 T, reload seg2 from shot11;
change rcur[0.001] from .68 to .66

another fizzle. OK, go back to granetz startup, he only had two in a row.
Sep 10 2002 03:05:36:107PM1020910020Steve Wolfeshot#20: plasma, Amanda seems happy with it.
Bob gets to draw the wiggles
Sep 10 2002 03:05:53:843PM1020910020Steve Wolfeshot#20: back to constant 5.4 T, reload seg2 from shot11;
One more try, increase pre-puff from 20 to 24 msec.
If this doesn't work I'll go back to shot#14 seg 1.

Granetz will take over for shot 21.
Sep 10 2002 03:09:30:083PM1020910020Robert GranetzShot 20 -- Plasma. Good shot. 1 MA, 5.4 T (constant), nebar=2.0e20 m-3.
Lots of hard x-rays.

Next shot: put in Btor waggles, as prescribed in updated MP,
lengthen Ip flattop to t=1.69 s, increase early gas puffing.
Sep 10 2002 03:19:15:287PM1020910021Robert GranetzShot 21 -- Fizzle.

Next shot: reduce pre-fill by 2 ms.
Sep 10 2002 03:36:57:767PM1020910022Robert GranetzShot 22 -- Plasma. Good shot. 1 MA, with small Btor wiggles of about half
the amplitude that we wanted. dI_tf/dt is also about half the
limit as well. Hard x-rays are gone. H/D=0.3-0.4 .

Next shot: put in square steps for the Btor waggles, increase
argon puff to 50 ms.
Sep 10 2002 03:42:42:993PM1020910023Robert GranetzShot 23 -- Fizzle.

Next shot: no changes
Sep 10 2002 03:56:04:280PM1020910024Robert GranetzShot 24 -- Fizzle. Two in a row. Current is rising a little faster than
on shot 22.

Next shot: increase pre-fill puff by 2 ms.
Sep 10 2002 04:31:38:520PM1020910025Robert GranetzShot 25 -- Plasma. Good shot. 1 MA with Btor wiggles. Apparently the
square programming gave too much noise in the alternator house.

Next shot: reprogram the TF waggles as slower ramps. Move
the TF invert time to 1.7 s.
Sep 10 2002 04:34:58:353PM1020910026Robert GranetzShot 26 -- Fizzle. Ip rise is definitely slower...maybe too slow.

Next shot: subtract 1 ms from pre-fill puff
Sep 10 2002 04:55:29:933PM1020910027Robert GranetzShot 27 -- Plasma. Good shot. 1 MA with Btor waggles. Final Btor flattop
at 5.6 T was way too short.

Next shot: more adjustment of the Btor waggles to get the ramps
to turn out more like we want. No changes to the startup.
Sep 10 2002 05:13:18:227PM1020910028Robert GranetzShot 28 -- Fizzle. Darn!

End of run.

Engineering Operator Comments
ShotTimeTypeStatusComment
109:48:01:950AMPlasmaOk
210:12:33:457AMPlasmaOk
310:28:24:637AMPlasmaOk
410:42:07:220AMPlasmaOk
510:57:59:323AMPlasmaOk
611:17:06:727AMPlasmaBadigor fault
711:29:51:857AMPlasmaOk
811:56:05:180AMPlasmaOk
912:08:52:773PMPlasmaOk
1012:22:18:200PMPlasmaOk
1112:35:12:877PMPlasmaOk
1212:48:09:087PMPlasmaOk
1301:01:45:527PMPlasmaOk
1401:18:22:240PMPlasmaOk
1501:40:16:477PMPlasmaOk
1601:54:52:687PMPlasmaOk
1702:09:13:710PMPlasmaOk
1802:22:11:777PMPlasmaOk
1902:35:22:217PMPlasmaOk
2002:48:38:957PMPlasmaOk
2103:10:45:350PMPlasmaOk
2203:23:51:807PMPlasmaOk
2303:39:21:003PMPlasmaOk
2403:52:31:993PMPlasmaOk
2504:05:32:937PMPlasmaOk
2604:30:29:643PMPlasmaOk
2704:43:28:447PMPlasmaOk
2804:59:26:643PMPlasmaOk