Alcator C-Mod Run 980109 Information

Miniproposals

Miniproposal: 168

Date Filed: 7/18/1996

Title: Exploration of the Effect on Core Confinement of Different Impurities

First Author: Bruce Lipschultz

Session Leader: Bruce Lipschultz (shots 1-38)

Operators
Session leader(s):	Bruce Lipschultz
Physics operator(s):	Steve Wolfe
Engineering operator(s):	Bill Cochran,Vinny Bertolino

Engineering Operator Run Comment
mp 168

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Entered: Jul 7 2004 03:49:17:773PM

Author: To Be Determined

run 980109

session leader: Bruce Lipschultz
physop: Steve Wolfe
engineering op: Vinnie Bertolino

Mini-proposal 168: "Exploration of the Effect on Core
Confinement of Different Impurities"

This run was fairly successful. We did see a correlation between a
degradation in confinement and the edge Te dropping with radiation. We still
need to look at the emissivity profiles and look at the localization of the
radiation at the edge with corresponding to the injected impurity (ReJean
and John G.). We had difficulty reaching the Prad/Pin point of 70%.
The plasma either disrupted out dropped out of H-mode.

Amanda reported that her quick glance at the data indicated that the
edge Te dropping was indicative of the pedestal width narrowing as opposed
to the overall profile dropping everywhere. It appeared that the Te slope
through the pedestal and in the core stayed fairly constant.

One other surprise was that the injected impurities did not appear to be going
into the divertor. This may have been due to the lateness of the
injection and the relatively long time it takes for the divertor to reach
equilibrium. However, during one shot where the plasma was primarily
in L-mode (shot 31) the Kr levels in the divertor were much higher.

The baseline shots for analysis are shots 12, 29 and 36
without injection (there may have been significant Ne or Kr around
anyway). The Ne and Kr shots are 24 (50% Prad w/Ne), 27/28 (66% Prad/Pin with
Ne), 37 (80% Prad/Pin for Kr) and 38 (66% Prad/Pin with Kr).

The details follow:

shot #1-4: Power tests

shot #5: MARFE at the beginning (till about 0.45 sec) followed by a good EDA
mode with 1.7 MW RF. No GPC, no injected impurities.

shot #6: fizzle

shot #7: fizzle

shot #8: MARFE at the beginning followed by 2.1 MW of RF. BUT no H-mode and
huge H-alpha during the RF. We get H-mode AFTER the RF turns off. Note also
that the GPC was not calibrated properly for that shot and the Tes are low.

shot #9: Went ok but no data - computer problem

shot #10: fizzle

shot #11: 2.2 MW of RF and EDA mode. Still increasing the RF power. Still
no impurity puff. Divertor probes still trying to get the right gain
settings so poor data. Significant recombination light at the outer divertor
up to 0.8 seconds. There appears to be a density variation across the
outer divertor profile looking at the line widths.

shot #12: 2.5 MW of RF and EDA mode. No impurity puff. Divertor probes almost
back. Baseline Prad/Pin about .4

shot #13: small amount of Ne (0.02 sec puff at 0.7 sec) had a slight
effect on the 2Pi bolo. Need more Ne.

shot #14: fizzle

shot #15: fizzle

shot #16: 2.5 MW & EDA mode. Ne increased to 0.03 sec width and triggered at
0.85. Prad/Pin ~ 0.5. Next shot we will do the TF sweep.

shot #18: same shot but with TF sweep. There seems to be rearrangements in
the ne, Te and rad power profiles?

shot #19: Same again. Still getting a spatial profile for McPherson.
JT says that he is able to identify the He-like Ne line which should
give a better measure of the core density.

shot #20: Same shot. The radiated power keeps changing from shot to shot,
The rumour is that the profiles of density and Te are what is causing this.
Goetz claims that the div. radiated power is not changing. Amanda's
sweep shifted to earlier time.

shot# 21: Larger Ne injection (60 ms). However, large Mo injection drops
it out of H-mode. EDA returns with the larger Ne levels.

shot #22: fizzle

shot #23: fizzle

shot #24: Great steady-state w/Ne. However the Prad/Pin is 50% still! Try for
more Ne.

shot #25: disrupts on the way down. Made it to Prad/Pin of 60%. 100 ms pulse
starting at .8 sec. Next shot more.

shot #26: dud (power supply)

shot #27: 2.5 MW of radiation. Prad/Pin ~ 66%. But large ELM-like occurence
in middle of shot (1.05 sec). Stay with this?

shot #28: repeat of #27.

shot #29: baseline shot, no Ne. However, big injection at 1.05 seconds.

shot #30: 50 ms of Kr started at 0.8 seconds. It seems to get in at .845 and
kills the H-mode at .87 seconds. Too much. We need to back off the Kr.

shot #31: No H-mode until almost 0.9 seconds. Then we have an awful looking
ELMy H-mode with a large amount of radiation. This may be coincident with
a MARFE on the inner divertor. John finds that there is 3x the
amount of Kr in the divertor during this shot (mostly L-mode) compared to
32. That is even with much less Kr injected -> H-mode causes the Kr
compression to degrade.

Shot #32: Short H-mode. Jim Terry reports that the Kr level was significant
even before the puff. Then the puff knocked it out of H-mode. Prad/Pin ~0.66.

shot #33: delayed H-mode. Kr puff only 20 ms. Still 2.7 MW in radiated power.

shot #34: shot ended quickly due to 'brick.

shot #35: still awful plasma (same Kr puff).

shot #36: Kr off and TF sweep off. Shot fairly nice.

shot #37: Kr on with 2 PSI and 20 ms puff. Got the H-mode. It starts
to degrade at 1.09 seconds. 2.8 MW of radiated power (67% radiation).
No TF sweep this shot. Significant loss in stored energy.

shot #38: Shot same as 27. Got the TF sweep for Amanda as well. Almost
2.5 MW of radiated power. Amanda gets 2 sweeps, one during the hotter
period and one later in the shot when there is more radiation.

Physics Operator Summaries

Entered: Jul 7 2004 04:36:58:537PM

Author: To Be Determined

Physop Summary for Friday, 980109

SL: Blip
PO: wolfe
EO: Bertolino,Cochran
MP 168

Run Plan
---------
This run is in support of MP#168, "Exploration of the Effect on Core
Confinement of Different Impurities".

Power tests will be conducted between 08:00 and 09:00, to investigate possible
instability in the OH2 response which seems to be contributing to our vertical
stability problems. Ian Hutchinson will serve as Session Leader for these
tests.

Engineering setup:
------------------
Two hours of ECDC in Deuterium prior to run.

For power tests:
TF under hybrid control, current limit and timing as on 980107025.
Fizzle detector start moved late (1.5 sec)
OH1,OH2U and OH2L under hybrid control.
PLC Limits [-10,10],
start=-.4sec, switch close=-0.2, open=+2 (no commutation),
crowbar=2.1, invert=1.2sec.
We will turn the supplies on one at a time.
Gas puffs disabled. Plenums filled as indicated below.

For plasma operation (first shot):
Engineering setup as on 980107025, except TF current limit set to
183kA (approximately 6T+ headroom)
TF under hybrid control
Remember to set the fizzle detector back to .08
Gas setup - fill K-side with 30 PSI of D2, hybrid enable
fill B-top with 6 PSI of D2, hybrid enable
fill B-side-lower with 4 PSI of Kr, hybrid disabled
fill J-bottom with 4 PSI of Ne hybrid disabled

The following gases will be used during this run:
D2,Neon,Argon,Krypton, and Nitrogen. These bottles
are presently installed.
Following the run the Neon bottle should be replaced
with Helium for ECDC over the weekend and
running Helium plasmas next Tuesday.

ECE gate valve enabled; others if diagnosticians are ready.

Power Tests:
-----------
Start from previously prepared shot with OH's at -5000 amps, with an
oscillating voltage waveform chirping from 40-120Hz (pcs$wolfe:pcs_999).
Run OH1, OH2U, OH2L power supplies one at a time, then perhaps together. Run TF pulse
for all cases to include effect of alternator loading. Look for resonances in
response at some range of frequencies.

Plasma Run:
-----------
The goal of this run is to assess the effect of various impurity gases on
global confinement.

We will start from a target shot taken from 980107025, but with increased TF=5.7T
to avoid cutoff of the ECE. The TF will be ramped up by 7.5kA (~5%) during the shot
for ECE pedestal measurements on some shots (not the first). The initial seg2 is
now setup in pcs$wolfe:pcs_999 (but segment 2 is turned off).

The planned shot sequence is:
(1) Setup of H-mode plasma (3-4 shots)

(2) Injection of Ne to achieve Prad,main/PIN= 0.5. (J-bottom valve)
(5 shots for scan of McPherson + 2-3 setup shots).

(3) repeat (2) with Prad,main/PIN = 0.7 (5 shots).

(4) Injection of Kr to evaluate relative effect on profiles (3 shots). (B-side
lower). We may repeat steps 2 and 3 in Kr depending on results.
Between shots without holding up sequence, pump out J-bottom
and fill with N2

If time permits:
(5) Injection of N to achieve Prad,main/PIN = 0.5. (J-bottom valve)
(3 shots for scan of McPherson + 2-3 setup shots).

(6) repeat (5) with Prad,main/PIN = 0.7 (5 shots).

Results:
-------

The power tests were carried out, but no smoking gun with respect to the
oscillations on the OH supplies was found.

Parts 1-4 of the run plan were completed. Confinement degradation was
demonstrated with injected neon and krypton, and radiation profile and
pedestal measurements were made. Two shots, #8 and #31, failed to go into
H-mode with high input power levels, and seemed to have halpha signatures that
looked like the RF pulse; there was speculation about this being a
steady-state marfe in the vicinity of the inner nose.

The fizzle rate was higher today. A BR tweak, increasing the RCUR offset to
8000, and adding 15amps to EF4 eventually gave a successful startup, but also
gave late and somewhat variable breakdown times.

Details:
-------

Start PCS and confirm that the OH test shot is still loaded from last night.
Did a coldstart and got an A-matrix not responding error!
Re-tried the coldstart; worked ok this time. Don't know what was wrong the
first time.

The power tests were carried out on shots 1-4. #1-3 had TF plus OH2U, OH2L,
and OH1, respectively. It was noted that the pre-loaded waveform actually went
to 200Hz instead of 120Hz, as intended. Shot #2, with OH2l seemed to have a
possible resonance at just above 40Hz. It looked like each supply exhibited
gain of about 1.5 at low frequency and decreasing to nothing at higher
frequency. No obvious instabilities were observed. Shot 3 was OH1 and the
TF. The OH1 response seemed to role off faster than the OH2's. For shot 4 we
changed the waveform to ramp f from 20Hz to 80Hz and ran the two OH2's with
the TF. The supply response looked pretty much as expected, decreasing with
f. No resonance or instability was observed.

The first shot of the physics run was #5, which ran well with a long EDA
reaching 145kJ with 1.7MW of RF. Unfortunately GPC was not turned on for this
shot. TF was set at 160kA.

Shots 6 and 7 were fizzles. It turned out the cooling valve for EF4 upper was
not opening, so the EF4 coil imbalance was large and positive. Also the CII
signal on these shots was large (.008 and .01).

For Shot 8 adjusted Br offset from .006 to .0055. We got a full length plasma
with over 2MW of RF, but it stayed in L-mode until the RF turned off, then
went into H-mode. The H-alpha trace had a big square pulse that looked like
the RF pulse.

Shot 9 appeared to run well, and judging from the neutron noise on the TV had
a long H-mode, but DAQA crashed right after the shot and all data was lost.

For Shot 10 reduced the TF to 157kA, which should give 5.7T instead of
5.8T. Shot 10 fizzled.

Shots 11 and 12 had good H-modes with increasing RF power, to 2.5MW and 160kJ
on #12.

Neon injection began with shot #13, with a 20msec pulse at 0.7 sec. #14-15
fizzled as we tried to increase the neon level and radiated power. For shot 16
I changed the IC_EF4 from -1345 to -1330 to increase the early Bz; this seemed
to delay the breakdown but got a good plasma, with close to the desired
Prad/Pin~0.5. Shot 17 fizzled. Because it looked like Bz was coming in too
slowly, I started increasing the RCUR offset from 6300->7000->8000; this
seemed to work. Shots 18-20 were a McPherson sweep, with TF waggles for ECE
edge profiles.

Shot #21 had increased neon. I had put the EF4 back to -1345 because I didn't
like the late breakdown. While #21 worked, with early breakdown, it had a
hesitation. I brought it back to -1335 for #22, but it fizzled, as did #23
which was back to -1330. For shot #24 I dropped the Br offset again, from
.0055 to .005. Note that at some point in the EF4 changes I moved the last
point on the flattop from -.003 to 0.0; this may have been a bad thing, as the
thrashes after commutation seemed worse than earlier in the day. At any rate,
with the Br at .005 and the EF4 at -1330, and RCUR offset = 8000, there were
no further fizzles from #24-#38, although the breakdowns varied from 6.3 to
7.8 msec. Shot #26 was a power supply dud, with EF3 breaker pulling out with a
forced shutdown before the pulse.

Shots 24-28 had increasing neon levels trying to get to a radiated power
fraction of 0.7. Shot #29 was a no-neon baseline shot.

There was a suspicion that the TF sweep was somehow related to injections and
eruptions from the antenna on some of these shots, typically at 1.0 to 1.1
sec. I believe this was a red herring, but we moved the sweep time and tried
an in-and-out sweep, and also turned the sweep off for a couple of shots
during the next sequence. See the logbook for what happened when.

Shot 30-35, and 37-38 were krypton puff shots. The first try,#30, used a
50msec puff at 4psi, and this was clearly too much; it killed the H-mode
almost immediately. Subsequent shots seemed to still have substantial Kr
levels around even before the puff. Shot 31 was similar to #8 in that it
stayed in L-mode until 0.9sec, with a flat H-alpha trace. Shot 36 was a
no-puff (and no TF sweep) shot that got back to a long EDA, but with somewhat
lower confinement, a stored energy of 147kj, compared to 160. Good Kr shots
which stayed in H-mode but showed degrading comfinement during the pulse, were
#37-38, with 20msec puff at 1.9psi. Shot #38 had a TF sweep starting at
0.9sec.

After the run, John Goetz ran some puffs to calibrate the divertor RGA for Ne,
Ar, and Kr. Tommy Toland then replaced the Helium bottle where the neon bottle
had been. Helium ECDC is scheduled to take place over the weekend.

Problems:
---------

The first coldstart of the hybrid gave a "a-matrix not responding"
error. Repeating the coldstart fixed it.

We lost data from one shot (#9) to a DAQA crash.

The EF3 breaker pulled before the shot on #26, causing a dud.

Scorecard:
----------
Tests 4
Duds 1 (power supply)
Fizzles 8
plasmas 25 (data lost on 1 due to DAQA crash)
======= ==
Total 38

Session Leader Comments

Jan 9 1998 09:27:12:360AM 980109005 Bruce Lipschultz MARFE at the beginning (till about 0.45 sec) followed by a good EDA mode with 1.7 MW RF. No
GPC, no injected impurities.

Jan 9 1998 10:05:15:730AM 980109008 Bruce Lipschultz
MARFE at the beginning followed by 2.1 MW of RF. BUT no H-mode and
huge H-alpha during the RF. We get H-mode AFTER the RF turns off. Note also
that the GPC was not calibrated properly for that shot and the Tes are low

Jan 9 1998 10:51:04:550AM 980109011 Bruce Lipschultz
2.2 MW of RF and EDA mode. Still increasing the RF power. Still
no impurity puff. Significant recombination light at the outer divertor
up to 0.8 seconds. There appears to be a density variation across the
outer divertor profile looking at the stark line widths.

Jan 9 1998 11:07:17:890AM 980109012 Bruce Lipschultz
2.5 MW of RF and EDA mode. No impurity puff. Divertor probes almost
back.

Jan 9 1998 11:10:42:240AM 980109013 Bruce Lipschultz
small amount of Ne (0.02 sec puff at 0.7 sec) had a slight
effect on the 2Pi bolo. Need more Ne.

Jan 9 1998 12:03:14:780PM 980109016 Bruce Lipschultz
shot 16: 2.5 MW & EDA mode. Ne increased to 0.03 sec width and triggered at
0.85. Prad/Pin ~ 0.5. Next shot we will do the TF sweep.

Jan 9 1998 12:33:56:300PM 980109018 Bruce Lipschultz
shot #18: same shot but with TF sweep. There seems to be rearrangements in
the ne, Te and rad power profiles?

Jan 9 1998 12:35:48:690PM 980109019 Bruce Lipschultz
shot #19: Same again. Still getting a spatial profile for McPherson. JT says that he is
able to identify the He-like Ne line which should give a better measure of the core density.

Jan 9 1998 12:43:35:850PM 980109020 Bruce Lipschultz
shot #20: Same shot. The radiated power keeps changing from shot to shot,
The rumour is that the profiles of density and Te are what is causing this.
Goetz claims that the div. radiated power is not changing.

Jan 9 1998 01:02:43:620PM 980109021 Bruce Lipschultz
shot# 21: Larger Ne injection (60 ms). However, large Mo injection drops
it out of H-mode. EDA returns with the larger Ne levels.

Jan 9 1998 01:48:47:980PM 980109024 Bruce Lipschultz
shot #24: Great steady-state w/Ne. However the Prad/Pin is 50% still! Try for
more Ne.

Jan 9 1998 01:57:05:490PM 980109025 Bruce Lipschultz shot #25: disrupts on the way down. Made it to Prad/Pin of 60%. 100 ms pulse
starting at .8 sec. Next shot more.

Jan 9 1998 02:28:30:870PM 980109027 Bruce Lipschultz shot #27: 2.5 MW of radiation. Prad/Pin ~ 66%. But large ELM-like occurence
in middle of shot (1.05 sec). Stay with this?

Jan 9 1998 02:43:29:560PM 980109028 Bruce Lipschultz shot #28: repeat of #27.

Jan 9 1998 02:46:49:020PM 980109029 Bruce Lipschultz shot #29: baseline shot, no Ne. However, big injection at 1.05 seconds.

Jan 9 1998 03:18:53:990PM 980109030 Bruce Lipschultz shot #30: 50 ms of Kr started at 0.8 seconds. It seems to get in at .845 and
kills the H-mode at .87 seconds. Too much. We need to back off the Kr.

Jan 9 1998 03:33:37:050PM 980109031 Bruce Lipschultz shot #31: No H-mode until almost 0.9 seconds. Then we have an awful looking
ELMy H-mode with a large amount of radiation. This may be coincident with
a MARFE on the inner divertor. John finds that there is 3x the
amount of Kr in the divertor during this shot (mostly L-mode) compared to
32. That is even with much less Kr injected -> H-mode causes the Kr
compression to degrade.

Jan 9 1998 03:52:11:070PM 980109032 Bruce Lipschultz Shot #32: Short H-mode. Jim Terry reports that the Kr level was significant
even before the puff. Then the puff knocked it out of H-mode. Prad/Pin ~0.66.

Jan 9 1998 04:04:36:900PM 980109033 Bruce Lipschultz shot #33: delayed H-mode. Kr puff only 20 ms. Still 2.7 MW in radiated power.

Jan 9 1998 04:14:00:750PM 980109034 Bruce Lipschultz shot #34: shot ended quickly due to 'brick.

Jan 9 1998 04:25:13:180PM 980109035 Bruce Lipschultz shot #35: still awful plasma (same Kr puff).

Jan 9 1998 04:35:09:110PM 980109036 Bruce Lipschultz shot #36: Kr off and TF sweep off. Shot fairly nice.

Jan 9 1998 04:59:08:140PM 980109037 Bruce Lipschultz shot #37: Kr on with 2 PSI and 20 ms puff. Got the H-mode. It starts
to degrade at 1.09 seconds. 2.8 MW of radiated power (67% radiation).
No TF sweep this shot. Significant loss in stored energy.

Jan 9 1998 05:21:36:840PM 980109038 Bruce Lipschultz shot #38: Shot same as 27. Got the TF sweep for Amanda as well. Almost
2.5 MW of radiated power. Amanda gets 2 sweeps, one during the hotter
period and one later in the shot when there is more radiation.

Physics Operator Comments

Jan 7 1998 05:09:12:490PM Ian Hutchinson Having set up the controllers in segment.
Note that the gains are up to 2 for OH1, 4 for OH2.
Draw in the 5000 A traces from -.2 to 1s.
Draw in gains .25 OH1, .5 OH2 as a complete guess. Need to calculate.

Jan 7 1998 05:09:56:340PM Ian Hutchinson OH2 testing set up.

Copied segment 1 OH1 and OH2U to segment 4.
Zeroed segment 1.
Copied back OH1 and OH2U to segment 1, 2 versions of OH2.
OH2 U went into predictor, was 0.5 each on OH2U and OH2L (we were lying,

this was really controlling the average current.) set to 1. OH2U.
in controller, was 0.00575 OH2U and OH2L removed OH2L.
Now this really IS an OH2U wire.
Asks for factor. Was.00035 now set to .0003 lower than offered numbers.
Other wire. Change name to
IC_OH2L. Do the corresponding things from the above to make this so.
Complains about predictor. Had to use call and then customize.
Complains about predictor having zero weights. Not true.
When brought back things seems ok.

Did this first but lost entry.

Jan 7 1998 05:12:43:010PM Ian Hutchinson Saved to [.mds.bus] shot 1

Jan 7 1998 05:31:07:340PM Ian Hutchinson Constructed a chirped signal via:

_t=ramp(701)/700.,_s=10.*sin(2.*3.142*(40.+80.*_t)*_t)

Played around with different ramp numbers. 1000 messed up the smoothing
500-700 gave pretty similar answers. It looks reasonable when imported
into PCS, though we are nearly aliased.

Saved scope in [hutch.mds.bus]chirped.dat

Copied signal into OH1 and OH2L V traces.
Stretched the OH1 trace to +-20V (from +-10) using shift ctrl.

Save as shot 2.

Jan 8 1998 03:35:33:070PM Steve Wolfe Modifying Ian's shot#2 in seg1:

Rename seg 1 "OH test"

Copy TF V trace from segment 2

Increase gain on OH1 to 2.5 and OH2's to 5 for t<0 (note that OH2L gain was still like
a normal startup, hadn't been set as in Ian's notes).

Save as USER9:[WOLFE.MDS.SHOTS.HYBRID.PCS] shot 980109999

Jan 8 1998 03:51:08:930PM Steve Wolfe Tried looking at how many points there are, and found I needed to do a build all to get the
loadables written. Did that and stored the result in shot 998.

The answer is that there are 525 points in the V_OH1 waveform (Wavegen 17), and the same in
OH2U and OH2L. Josh says the max number of wavegen points is nearly 4000 total for all
channels, so we should be ok. Since the three oh's are all at the same time, there should be
alot of headroom. We'll test after the run anyway.

Jan 8 1998 04:24:44:430PM Steve Wolfe While I'm at it, set up segment 2 for the MP168 part of run.

Import segment 2 from 980107025
Increase TF_CURRENT to 160KA (should give 5.7T)
Draw 20msec pulses @.7sec on PG5 and PG1.
I'll need to load a good startup (probably 980107025, just to be foolishly consistent)
and copy the TF trace into it.

Delete the old pcs$wolfe:pcs_999.*;* and
Save as pcs$wolfe:pcs_999

Jan 8 1998 04:43:06:920PM Ian Hutchinson Calculated the time constants of the closed loop circuits of OH1 and OH2.
With the controllers as .05775 and .00575 respectively, they are \tau=1/(P + Q_i)
where P is the P gain of PID and Q_1=.052, Q_2=.1.
Therefore a gain of 1 gives a time-constant of 0.1s which translates to a \omega.\tau
of 25 at 40Hz: four percent compensation of the oscillating voltage only.
At this gain, the DC error will be equal to Q_i, 5 and ten percent respectively.
Sounds about right.

Jan 8 1998 04:51:21:620PM Steve Wolfe Ian says the right gains for the t>0 part of the shot should be 1.0, rather than what he set up
earlier.

Make this change.
Build all (why not?)
Once again, delete the existing pcs$wolfe: 999 (Shouldn't matter or be necessary)
Save as pcs$wolfe:pcs_999.*

Jan 8 1998 05:23:56:570PM Steve Wolfe Thursday's Run is over. Now to test the shot we've prepared.

Load from my pcs$wolfe: shot 999
Load/clean
Bring up hybrid_control
Take shot 374
Got an error after hitting trigger:
%SYSTEM-F-NOLOGNAM, no logical name match
% Compiled module: MDS$VMS_ERROR.
% XMANAGER: Caught unexpected error from client application. Message follows...
% Error returned from TCL command
% %SYSTEM-F-NOLOGNAM, no logical name match

Get out and do a REMCAM
Try again (shot 375)
Looks like it worked. Waveforms are ugly, but that was expected from limited number of points
in wavegen traces.

Jan 9 1998 06:49:45:370AM Steve Wolfe un Plan for Friday, 980109

Engineering setup:
------------------
For plasma operation (first shot):
Engineering setup as on 980107025, except TF current limit set to
183kA (approximately 6T+ headroom)
TF under hybrid control
Remember to set the fizzle detector back to .08
Gas setup - fill K-side with 30 PSI of D2, hybrid enable
fill B-top with 6 PSI of D2, hybrid enable
fill B-side-lower with 4 PSI of Kr, hybrid disabled
fill J-bottom with 4 PSI of Ne hybrid disabled

The following gases will be used during this run:
D2,Neon,Argon,Krypton, and Nitrogen. These bottles
are presently installed.
Following the run the Neon bottle should be replaced
with Helium for ECDC over the weekend and
running Helium plasmas next Tuesday.

ECE gate valve enabled; others if diagnosticians are ready.

Jan 9 1998 06:51:28:740AM Steve Wolfe un Plan for Friday, 980109

SL: Blip
PO: wolfe
MP 168

This run is in support of MP#168, "Exploration of the Effect on Core
Confinement of Different Impurities".

Power tests will be conducted between 08:00 and 09:00, to investigate possible
instability in the OH2 response which seems to be contributing to our vertical
stability problems. Ian Hutchinson will serve as Session Leader for these
tests.

Engineering setup:
------------------
Two hours of ECDC in Deuterium prior to run.

For power tests:
TF under hybrid control, current limit and timing as on 980107025.
Fizzle detector start moved late (1.5 sec)
OH1,OH2U and OH2L under hybrid control.
PLC Limits [-10,10],
start=-.4sec, switch close=-0.2, open=+2 (no commutation),
crowbar=2.1, invert=1.2sec.
We will turn the supplies on one at a time.
Gas puffs disabled. Plenums filled as indicated below.

Jan 9 1998 06:52:35:420AM Steve Wolfe Power Tests:
-----------
Start from previously prepared shot with OH's at -5000 amps, with an
oscillating voltage waveform chirping from 40-120Hz (pcs$wolfe:pcs_999).
Run OH1, OH2U, OH2L power supplies one at a time, then perhaps together. Run TF pulse
for all cases to include effect of alternator loading. Look for resonances in
response at some range of frequencies.

Jan 9 1998 06:52:51:880AM Steve Wolfe Plasma Run:
-----------
The goal of this run is to assess the effect of various impurity gases on
global confinement.

We will start from a target shot taken from 980107025, but with increased TF=5.7T
to avoid cutoff of the ECE. The TF will be ramped up by 7.5kA (~5%) during the shot
for ECE pedestal measurements on some shots (not the first). The initial seg2 is
now setup in pcs$wolfe:pcs_999 (but segment 2 is turned off).

Jan 9 1998 06:53:19:210AM Steve Wolfe The planned shot sequence is:
(1) Setup of H-mode plasma (3-4 shots)
(2) Injection of Ne to achieve Prad,main/PIN= 0.5. (J-bottom valve)
(5 shots for scan of McPherson + 2-3 setup shots).

(3) repeat (2) with Prad,main/PIN = 0.7 (5 shots).

(4) Injection of Kr to evaluate relative effect on profiles (3 shots). (B-side
lower). We may repeat steps 2 and 3 in Kr depending on results.
Between shots without holding up sequence, pump out J-bottom
and fill with N2

If time permits:
(5) Injection of N to achieve Prad,main/PIN = 0.5. (J-bottom valve)
(3 shots for scan of McPherson + 2-3 setup shots).

(6) repeat (5) with Prad,main/PIN = 0.7 (5 shots).

Jan 9 1998 07:06:39:780AM Steve Wolfe OH test Shot is already loaded from last night.
Do a coldstart.
Got an A-matrix not responding error!
Try coldstart again. 07:00
Bitbus log looks ok this time. No errors, all matrices respond.
Hloader log looks ok.

Jan 9 1998 07:30:47:880AM Steve Wolfe While I'm waiting, put segment 4 back to a fiducial. Import segment 4 from 971217017.

Check on the gain on BP12_DE in ZCUR predictor; it is -15e3, not enough to account for
a significant error on ZCUR with a 25e-3 difference from BTOR offset between BP12_BC and
BP12_DE. I suspect actual offsets in the iso-amps, some of which are larger than this;
e.g. input 37 (BP08_BC) has a .1V (50mT) offset. These have drifted since the last campaign.
We probably should retweak these, but then shots from the last month would need adjusting.

Jan 9 1998 08:18:28:720AM 980109001 Steve Wolfe TF and OH2U
Get a 20V amplitude (40V p-p) at the low frequency, dying off at the higher frequency.

Next shot OH2L.

Jan 9 1998 08:37:01:470AM 980109001 Ian Hutchinson Shot 1 oscillating OH2U shows no resonance. Gain is about 1.5 too high at lowest
frequency. Roll off is quite rapid at the higher frequency. 3db point seems about .4s
which is around 90Hz. It should not be so fast so soon. For some reason that chirp is going
to 200 Hz.

Jan 9 1998 08:44:55:270AM 980109002 Ian Hutchinson OH2L seems to have a slight resonance at the lower end of the frequency
range. Not very severe.

We realize that the expression we were using was not correct for what
we had wanted. Still it gives us roughly a reasonable test.

Jan 9 1998 08:56:32:880AM 980109002 Steve Wolfe Shot 2: TF and OH2L
May show a small resonance arounf .1 sec (near 50Hz)

Jan 9 1998 08:51:10:600AM 980109003 Steve Wolfe shot 3: TF and OH1
seems to roll off much faster, and has some similar oscillations before t=0.

Jan 9 1998 08:56:24:040AM 980109003 Ian Hutchinson OH1 seems to roll off faster than the OH2s.

Jan 9 1998 09:01:55:310AM 980109004 Steve Wolfe shot 4: TF and both OH2's. Change chirp to 20Hz: 80Hz.
Note that previous expression was wrong, got to 200Hz.
Now using _s = sin($2pi*(20.+30*_t)*_t) to get top frequency of 80Hz

No apparent resonance in that. It looks like they are pretty linear.

Jan 9 1998 09:03:12:710AM 980109004 Ian Hutchinson Slowed down the chirp to 20-60Hz. Ran OH2U/L simultaneously.
No signs of anything bad happening.

Jan 9 1998 09:23:19:040AM 980109005 Steve Wolfe Shot 5: Begin plasma run
Load startup from 980107025.
Copy TF waveform from seg 2 to seg 1
Turn on seg 2
ECE, pcx, moly monitor and VUV gate valves open.
RF will try for 1.5MW this shot (wake up call)

plasma full length.
Long EDA H-mode.
Startup looks good.
145kJ, H=1.7, Prf=1.7MW

Jan 9 1998 09:52:48:160AM 980109007 Steve Wolfe Shot 6: repeat with more RF (we hope).
Amanda is trying to get GPC back on the air; didn't show up on shot 5.
fizzle. null looked bad on previous, and EF4's weren't cold.
this time breakdown is a little late.
EF4's still imbalanced (difference is positive); turns out the EF4U cryo valve wasn't open because
of hysteresis. It was at -167, compared to -184 on lower.

shot 7:When EF4U is down to -177 try again:
another fizzle. balance is better, but not there yet.
CII signal is up to .01. Br is still positive.

Next shot, reduce Br offset.

Jan 9 1998 10:05:27:790AM 980109008 Steve Wolfe Shot 8: Br offset from .006 to .0055
I suspect the real problem is dirt. CII iwas at .01 on shot 7, .008 on shot 6.

plasma full length, still a big early marfe.
EF4 balance to 0. now. CII down to .006
Got over 2MW RF, no H-mode during RF, H-mode after RF.
H-alpha has a big flat enhancement.

Jan 9 1998 10:24:29:530AM 980109009 Steve Wolfe Shot 9: repeat.
plasma. full length,
Looks like a good H-mode from TV. DAQA crashed right after shot, no data.

For next shot, reduce TF current from 160->157kA. It was noted that on shot 8 we were
at 5.8T instead of 5.7.

Tom tried to recoverf the data from shot 9, but it is gone.

Jan 9 1998 10:34:44:900AM 980109010 Steve Wolfe Shot 10: repeat with reduced TF current from 160->157kA.
It was noted that on shot 8 we were at 5.8T instead of 5.7. .

fizzle. EF4 imbalance down to -30A. CII at .008 again.

Jan 9 1998 10:43:26:310AM 980109011 Steve Wolfe Shot 11: repeat with reduced TF current from 160->157kA.
It was noted that on shot 8 we were at 5.8T instead of 5.7. .

plasma. Looked on the TV like #9.
Looks like a good EDA. Prf=2.2MW, W=147kJ.
There still seems to be a problem with ECE calibration?

Jan 9 1998 10:56:08:680AM 980109012 Steve Wolfe Shot 12: repeat, try for .4MW more RF.
Note that CII was down to .004 on shot 11.

plasma, 2.5MW, H-mode. 160kJ
Next shot Neon

Jan 9 1998 11:07:43:660AM 980109013 Steve Wolfe Shot 13: repeat with 20msec Ne pulse at 0.7sec
plasma. H-mode. Only a small increase in 2pi signal

Jan 9 1998 11:23:59:510AM 980109014 Steve Wolfe Shot 14: Delay Ne pulse to .85sec, increase to 30msec
fizzle. CII at .006, bd a little late (6.3msec)
Br maybe a little positive. Just try again.

Jan 9 1998 11:27:34:940AM 980109015 Steve Wolfe Shot 15: repeat
Delay Ne pulse to .85sec, increase to 30msec
another fizzle. Try some tweaks.

Jan 9 1998 11:33:51:590AM 980109015 Steve Wolfe Shot 15: repeat
Delay Ne pulse to .85sec, increase to 30msec

another fizzle. CII is down to .003, it isn't that.
bd at .005, nice and early.
Br looks a little negative, but null looks good. It got to 40kA and hit something.
Looks to me like Bz isn't coming in fast enough.

Jan 9 1998 11:51:30:530AM 980109016 Steve Wolfe Shot 16: EF4 from -1345->-1330
Delay Ne pulse to .85sec, increase to 30msec
plasma. H-mode; I doubt that the EF4 tweak did it, though.
Nice current rise; it's at 55ka at 15msec, with Bz of .007.
bd is actually later, 6.8msec.
I still am not happy with the startup. I may want to tweak the RCUR offset.

Got more Ne this time, about 200kW on the 2pi.
Start the scan, TF waggle on next shot.

Jan 9 1998 11:56:50:100AM 980109017 Steve Wolfe Shot 17: TF waggle at 1.0sec to -164500kA.
No startup tweak this time.

fizzle, should have tweaked.

Jan 9 1998 12:14:20:240PM 980109018 Steve Wolfe Shot 18: RCUR offset in segment 1 to 7000
TF waggle at 1.0sec to -164500kA.

plasma, H-modes, etc. When it goes it goes.
field in somewhat faster, 10mT @15msec.

Little drop in neutron rate and Halpha at peak of radiation.

Jan 9 1998 12:27:07:750PM 980109019 Steve Wolfe shot 19: repeat
plasma. breakdown is later.

Jan 9 1998 12:37:25:210PM 980109020 Steve Wolfe shot 20: Move TF waggle to .73 sec
Seg 1 RCUR offset from 7000 to 8000

plasma, H-modes

Next shot more Neon.

Jan 9 1998 12:57:17:010PM 980109021 Steve Wolfe shot 21: INcrease neon pulse width to 60msec.
Bring EF4 back to -1345A

plasma. bd earlier 5.8msec, but a slight hesitation.
Two EDA periods this time. Big injection at .93

Jan 9 1998 01:10:10:510PM 980109022 Steve Wolfe shot 22: EF4 to -1335; move TF waggle back to 1sec
fizzle. hesitation seemed to get it, even though I went part way back.
Br is positive again. bd is later 8msec.

Jan 9 1998 01:16:26:330PM 980109023 Steve Wolfe shot 23: EF4 to -1330; That should be essentially no change, but back to a setting that ran.
TF waggle at 1sec
fizzle.

Jan 9 1998 01:35:36:350PM 980109024 Steve Wolfe shot 24: Br offset from .0055 to .005
TF waggle at 1sec

plasma. bd is even later 7.5msec, br is almost unchanged except for a thrash at 3msec.
Radiated power is up, no injection this time.

Jan 9 1998 01:56:03:990PM 980109025 Steve Wolfe shot 25: Need more radiation. Move Neon pulse to 0.8 sec and turn on for 100msec

plasma, ends a bit earlier in rampdown 1.38sec
bd slightly earlier. Still a big Br jump around 3msec.

Neon puff drops the halpha, 2MW of Prad.
Clear change in Halpha, lower stored energy

Jan 9 1998 02:03:05:620PM 980109026 Steve Wolfe shot 26: Need still more radiation. Move Neon pulse to 0.8 sec and turn on for 150msec
dud
EF3 breaker pulled before shot. EF3 had 4KA of induced current at t=0.

Jan 9 1998 02:24:37:950PM 980109027 Steve Wolfe shot 27: Repeat try with 150msec Ne puff.

plasma. 1.33sec
Almost completely suppresses the EDA Halpha level, got an ELM at 1.03 sec

bd at 6.3msec, rise is ok.
For some reason, the last point on the EF4 flattop was at -.003 sec, but at some
point today I've moved it to t=0. Hard to believe this matters, but it may be related to the
Br thrash at +3msec.

Don't do amything about it now. Wait till a fizzle.

Jan 9 1998 02:33:54:780PM 980109028 Steve Wolfe shot 28: move Ne puff to 750msec, width 140ms

plasma . Almost identical.
bd back to 7.2msec, no hesitation. Leave it be.

Next shot no neon

Jan 9 1998 02:46:30:590PM 980109029 Steve Wolfe shot 29: Turn off J-bottom. No neon.
plasma back to 1.6sec length

Big injection at 1.05sec

Jan 9 1998 03:11:47:150PM 980109030 Steve Wolfe shot 30: Krypton B-side lower pulse at .8 sec for 50msec
disrupts just into ranpdown.
Lost the H-mode at .87sec
bolo gets to 3MW.

Jan 9 1998 03:27:12:470PM 980109031 Steve Wolfe shot 31: Shorten Kr puff to 35msec.
Change TF sweep to up and down +/- 4kA, still starting at 1.0sec

plasma to 1.36sec.
Long delay before L-H at .87 sec, then very ELMy.
Initial Halpha seems to follow RF, similar to shot 8

Jan 9 1998 03:39:32:770PM 980109032 Steve Wolfe shot 32: No changes, let the plasma adapt?
plasma to 1.4sec, One transmitter shut off early.
goes into H-mode promptly, but density turns over at .87, H-L at .918

Jan 9 1998 03:55:06:670PM 980109033 Steve Wolfe shot 33: Reduce Kr to 20msec, extend reverse sweep on TF to 1.15sec
plasma to 1.46,; Kr must be going away.
Late L-H again.

Jan 9 1998 04:10:43:100PM 980109034 Steve Wolfe shot 34: Repeat it like this.
Disrupted early at .3sec.
Looks like multiple bricks. 2pi goes to 8MW

Jan 9 1998 04:22:38:870PM 980109035 Steve Wolfe shot 35: Move TF ramp to 0.9sec and make it unipolar again (157 to 164.5kA) in 100msec

plasma to 1.5sec
L-H at .72sec, start to lose EDA at .86, ELM or H-L at 1.00, second h-mode at 1.02

Next shot turn off TF sweep.

Jan 9 1998 04:34:14:370PM 980109036 Steve Wolfe shot 36: Turn off TF ramp and Kr puff.
plasma to 1.63 sec, long EDA
2pi at 800kW, 147kJ

Next shot reduce Kr plenum pressure to 1.9psi and turn on the 20msec puff again

Jan 9 1998 04:51:21:500PM 980109037 Steve Wolfe shot 37: 20msec Kr puff @1.9psi in plenum (was 4) at .8sec

plasma to 1.57sec, long EDA, H-alpha starts dropping
ELmy behavior aroumd 1.08, followed by short RF trip.
Stored energy starts at 155kJ, drops linearly to 117 by end of RF pulse.
bolo goes to 2.8MW

Tfsweep back on next shot.

Jan 9 1998 05:09:14:540PM 980109038 Steve Wolfe shot 38: 20msec Kr puff @1.9psi in plenum (was 4) at .8sec
TF sweep starting at 0.9sec

plasma to 1.54sec
one long EDA, similar to 37
stored energy is down all the way through, dropping to 119kJ
Two injections early in RF pulse.
bolo ends up at 2.2MW prad.

Engineering Operator Comments

Shot Time Type Status Comment

1 08:13:48:570AM Test Ok

2 08:32:53:260AM Test Ok

3 08:48:24:180AM Test Ok

4 08:58:11:960AM Test Ok

5 09:14:21:620AM Plasma Ok

6 09:30:57:770AM Plasma Ok

7 09:44:25:420AM Plasma Ok

8 09:54:29:850AM Plasma Ok

9 10:08:21:770AM Plasma Bad computer crash

10 10:26:53:090AM Plasma Ok

11 10:35:48:350AM Plasma Ok

12 10:49:16:490AM Plasma Ok

13 11:00:25:940AM Plasma Ok

14 11:17:22:950AM Plasma Ok

15 11:26:02:750AM Plasma Ok

16 11:37:29:380AM Plasma Ok

17 11:55:28:280AM Plasma Ok

18 12:04:28:840PM Plasma Ok

19 12:18:37:330PM Plasma Ok

20 12:32:36:660PM Plasma Ok

21 12:48:19:360PM Plasma Ok

22 01:03:22:590PM Plasma Ok

23 01:14:57:940PM Plasma Ok

24 01:27:50:180PM Plasma Ok

25 01:44:25:980PM Plasma Ok

26 01:58:50:190PM Plasma Ok

27 02:14:38:440PM Plasma Ok

28 02:28:02:370PM Plasma Ok

29 02:40:36:730PM Plasma Ok

30 03:00:36:720PM Plasma Ok

31 03:18:18:540PM Plasma Ok

32 03:31:56:030PM Plasma Ok

33 03:47:40:220PM Plasma Ok

34 04:05:36:050PM Plasma Ok

35 04:14:46:710PM Plasma Ok

36 04:26:41:560PM Plasma Ok

37 04:41:55:420PM Plasma Ok

38 04:56:29:960PM Plasma Ok

Session Leader Comments
Jan 9 1998 09:27:12:360AM	980109005	Bruce Lipschultz	MARFE at the beginning (till about 0.45 sec) followed by a good EDA mode with 1.7 MW RF. No GPC, no injected impurities.
Jan 9 1998 10:05:15:730AM	980109008	Bruce Lipschultz	MARFE at the beginning followed by 2.1 MW of RF. BUT no H-mode and huge H-alpha during the RF. We get H-mode AFTER the RF turns off. Note also that the GPC was not calibrated properly for that shot and the Tes are low
Jan 9 1998 10:51:04:550AM	980109011	Bruce Lipschultz	2.2 MW of RF and EDA mode. Still increasing the RF power. Still no impurity puff. Significant recombination light at the outer divertor up to 0.8 seconds. There appears to be a density variation across the outer divertor profile looking at the stark line widths.
Jan 9 1998 11:07:17:890AM	980109012	Bruce Lipschultz	2.5 MW of RF and EDA mode. No impurity puff. Divertor probes almost back.
Jan 9 1998 11:10:42:240AM	980109013	Bruce Lipschultz	small amount of Ne (0.02 sec puff at 0.7 sec) had a slight effect on the 2Pi bolo. Need more Ne.
Jan 9 1998 12:03:14:780PM	980109016	Bruce Lipschultz	shot 16: 2.5 MW & EDA mode. Ne increased to 0.03 sec width and triggered at 0.85. Prad/Pin ~ 0.5. Next shot we will do the TF sweep.
Jan 9 1998 12:33:56:300PM	980109018	Bruce Lipschultz	shot #18: same shot but with TF sweep. There seems to be rearrangements in the ne, Te and rad power profiles?
Jan 9 1998 12:35:48:690PM	980109019	Bruce Lipschultz	shot #19: Same again. Still getting a spatial profile for McPherson. JT says that he is able to identify the He-like Ne line which should give a better measure of the core density.
Jan 9 1998 12:43:35:850PM	980109020	Bruce Lipschultz	shot #20: Same shot. The radiated power keeps changing from shot to shot, The rumour is that the profiles of density and Te are what is causing this. Goetz claims that the div. radiated power is not changing.
Jan 9 1998 01:02:43:620PM	980109021	Bruce Lipschultz	shot# 21: Larger Ne injection (60 ms). However, large Mo injection drops it out of H-mode. EDA returns with the larger Ne levels.
Jan 9 1998 01:48:47:980PM	980109024	Bruce Lipschultz	shot #24: Great steady-state w/Ne. However the Prad/Pin is 50% still! Try for more Ne.
Jan 9 1998 01:57:05:490PM	980109025	Bruce Lipschultz	shot #25: disrupts on the way down. Made it to Prad/Pin of 60%. 100 ms pulse starting at .8 sec. Next shot more.
Jan 9 1998 02:28:30:870PM	980109027	Bruce Lipschultz	shot #27: 2.5 MW of radiation. Prad/Pin ~ 66%. But large ELM-like occurence in middle of shot (1.05 sec). Stay with this?
Jan 9 1998 02:43:29:560PM	980109028	Bruce Lipschultz	shot #28: repeat of #27.
Jan 9 1998 02:46:49:020PM	980109029	Bruce Lipschultz	shot #29: baseline shot, no Ne. However, big injection at 1.05 seconds.
Jan 9 1998 03:18:53:990PM	980109030	Bruce Lipschultz	shot #30: 50 ms of Kr started at 0.8 seconds. It seems to get in at .845 and kills the H-mode at .87 seconds. Too much. We need to back off the Kr.
Jan 9 1998 03:33:37:050PM	980109031	Bruce Lipschultz	shot #31: No H-mode until almost 0.9 seconds. Then we have an awful looking ELMy H-mode with a large amount of radiation. This may be coincident with a MARFE on the inner divertor. John finds that there is 3x the amount of Kr in the divertor during this shot (mostly L-mode) compared to 32. That is even with much less Kr injected -> H-mode causes the Kr compression to degrade.
Jan 9 1998 03:52:11:070PM	980109032	Bruce Lipschultz	Shot #32: Short H-mode. Jim Terry reports that the Kr level was significant even before the puff. Then the puff knocked it out of H-mode. Prad/Pin ~0.66.
Jan 9 1998 04:04:36:900PM	980109033	Bruce Lipschultz	shot #33: delayed H-mode. Kr puff only 20 ms. Still 2.7 MW in radiated power.
Jan 9 1998 04:14:00:750PM	980109034	Bruce Lipschultz	shot #34: shot ended quickly due to 'brick.
Jan 9 1998 04:25:13:180PM	980109035	Bruce Lipschultz	shot #35: still awful plasma (same Kr puff).
Jan 9 1998 04:35:09:110PM	980109036	Bruce Lipschultz	shot #36: Kr off and TF sweep off. Shot fairly nice.
Jan 9 1998 04:59:08:140PM	980109037	Bruce Lipschultz	shot #37: Kr on with 2 PSI and 20 ms puff. Got the H-mode. It starts to degrade at 1.09 seconds. 2.8 MW of radiated power (67% radiation). No TF sweep this shot. Significant loss in stored energy.
Jan 9 1998 05:21:36:840PM	980109038	Bruce Lipschultz	shot #38: Shot same as 27. Got the TF sweep for Amanda as well. Almost 2.5 MW of radiated power. Amanda gets 2 sweeps, one during the hotter period and one later in the shot when there is more radiation.

Physics Operator Comments
Jan 7 1998 05:09:12:490PM		Ian Hutchinson	Having set up the controllers in segment. Note that the gains are up to 2 for OH1, 4 for OH2. Draw in the 5000 A traces from -.2 to 1s. Draw in gains .25 OH1, .5 OH2 as a complete guess. Need to calculate.
Jan 7 1998 05:09:56:340PM		Ian Hutchinson	OH2 testing set up. Copied segment 1 OH1 and OH2U to segment 4. Zeroed segment 1. Copied back OH1 and OH2U to segment 1, 2 versions of OH2. OH2 U went into predictor, was 0.5 each on OH2U and OH2L (we were lying, this was really controlling the average current.) set to 1. OH2U. in controller, was 0.00575 OH2U and OH2L removed OH2L. Now this really IS an OH2U wire. Asks for factor. Was.00035 now set to .0003 lower than offered numbers. Other wire. Change name to IC_OH2L. Do the corresponding things from the above to make this so. Complains about predictor. Had to use call and then customize. Complains about predictor having zero weights. Not true. When brought back things seems ok. Did this first but lost entry.
Jan 7 1998 05:12:43:010PM		Ian Hutchinson	Saved to [.mds.bus] shot 1
Jan 7 1998 05:31:07:340PM		Ian Hutchinson	Constructed a chirped signal via: _t=ramp(701)/700.,_s=10.sin(2.3.142(40.+80._t)*_t) Played around with different ramp numbers. 1000 messed up the smoothing 500-700 gave pretty similar answers. It looks reasonable when imported into PCS, though we are nearly aliased. Saved scope in [hutch.mds.bus]chirped.dat Copied signal into OH1 and OH2L V traces. Stretched the OH1 trace to +-20V (from +-10) using shift ctrl. Save as shot 2.
Jan 8 1998 03:35:33:070PM		Steve Wolfe	Modifying Ian's shot#2 in seg1: Rename seg 1 "OH test" Copy TF V trace from segment 2 Increase gain on OH1 to 2.5 and OH2's to 5 for t<0 (note that OH2L gain was still like a normal startup, hadn't been set as in Ian's notes). Save as USER9:[WOLFE.MDS.SHOTS.HYBRID.PCS] shot 980109999
Jan 8 1998 03:51:08:930PM		Steve Wolfe	Tried looking at how many points there are, and found I needed to do a build all to get the loadables written. Did that and stored the result in shot 998. The answer is that there are 525 points in the V_OH1 waveform (Wavegen 17), and the same in OH2U and OH2L. Josh says the max number of wavegen points is nearly 4000 total for all channels, so we should be ok. Since the three oh's are all at the same time, there should be alot of headroom. We'll test after the run anyway.
Jan 8 1998 04:24:44:430PM		Steve Wolfe	While I'm at it, set up segment 2 for the MP168 part of run. Import segment 2 from 980107025 Increase TF_CURRENT to 160KA (should give 5.7T) Draw 20msec pulses @.7sec on PG5 and PG1. I'll need to load a good startup (probably 980107025, just to be foolishly consistent) and copy the TF trace into it. Delete the old pcs$wolfe:pcs_999.; and Save as pcs$wolfe:pcs_999
Jan 8 1998 04:43:06:920PM		Ian Hutchinson	Calculated the time constants of the closed loop circuits of OH1 and OH2. With the controllers as .05775 and .00575 respectively, they are \tau=1/(P + Q_i) where P is the P gain of PID and Q_1=.052, Q_2=.1. Therefore a gain of 1 gives a time-constant of 0.1s which translates to a \omega.\tau of 25 at 40Hz: four percent compensation of the oscillating voltage only. At this gain, the DC error will be equal to Q_i, 5 and ten percent respectively. Sounds about right.
Jan 8 1998 04:51:21:620PM		Steve Wolfe	Ian says the right gains for the t>0 part of the shot should be 1.0, rather than what he set up earlier. Make this change. Build all (why not?) Once again, delete the existing pcs$wolfe: 999 (Shouldn't matter or be necessary) Save as pcs$wolfe:pcs_999.*
Jan 8 1998 05:23:56:570PM		Steve Wolfe	Thursday's Run is over. Now to test the shot we've prepared. Load from my pcs$wolfe: shot 999 Load/clean Bring up hybrid_control Take shot 374 Got an error after hitting trigger: %SYSTEM-F-NOLOGNAM, no logical name match % Compiled module: MDS$VMS_ERROR. % XMANAGER: Caught unexpected error from client application. Message follows... % Error returned from TCL command % %SYSTEM-F-NOLOGNAM, no logical name match Get out and do a REMCAM Try again (shot 375) Looks like it worked. Waveforms are ugly, but that was expected from limited number of points in wavegen traces.
Jan 9 1998 06:49:45:370AM		Steve Wolfe	un Plan for Friday, 980109 Engineering setup: ------------------ For plasma operation (first shot): Engineering setup as on 980107025, except TF current limit set to 183kA (approximately 6T+ headroom) TF under hybrid control Remember to set the fizzle detector back to .08 Gas setup - fill K-side with 30 PSI of D2, hybrid enable fill B-top with 6 PSI of D2, hybrid enable fill B-side-lower with 4 PSI of Kr, hybrid disabled fill J-bottom with 4 PSI of Ne hybrid disabled The following gases will be used during this run: D2,Neon,Argon,Krypton, and Nitrogen. These bottles are presently installed. Following the run the Neon bottle should be replaced with Helium for ECDC over the weekend and running Helium plasmas next Tuesday. ECE gate valve enabled; others if diagnosticians are ready.
Jan 9 1998 06:51:28:740AM		Steve Wolfe	un Plan for Friday, 980109 SL: Blip PO: wolfe MP 168 This run is in support of MP#168, "Exploration of the Effect on Core Confinement of Different Impurities". Power tests will be conducted between 08:00 and 09:00, to investigate possible instability in the OH2 response which seems to be contributing to our vertical stability problems. Ian Hutchinson will serve as Session Leader for these tests. Engineering setup: ------------------ Two hours of ECDC in Deuterium prior to run. For power tests: TF under hybrid control, current limit and timing as on 980107025. Fizzle detector start moved late (1.5 sec) OH1,OH2U and OH2L under hybrid control. PLC Limits [-10,10], start=-.4sec, switch close=-0.2, open=+2 (no commutation), crowbar=2.1, invert=1.2sec. We will turn the supplies on one at a time. Gas puffs disabled. Plenums filled as indicated below.
Jan 9 1998 06:52:35:420AM		Steve Wolfe	Power Tests: ----------- Start from previously prepared shot with OH's at -5000 amps, with an oscillating voltage waveform chirping from 40-120Hz (pcs$wolfe:pcs_999). Run OH1, OH2U, OH2L power supplies one at a time, then perhaps together. Run TF pulse for all cases to include effect of alternator loading. Look for resonances in response at some range of frequencies.
Jan 9 1998 06:52:51:880AM		Steve Wolfe	Plasma Run: ----------- The goal of this run is to assess the effect of various impurity gases on global confinement. We will start from a target shot taken from 980107025, but with increased TF=5.7T to avoid cutoff of the ECE. The TF will be ramped up by 7.5kA (~5%) during the shot for ECE pedestal measurements on some shots (not the first). The initial seg2 is now setup in pcs$wolfe:pcs_999 (but segment 2 is turned off).
Jan 9 1998 06:53:19:210AM		Steve Wolfe	The planned shot sequence is: (1) Setup of H-mode plasma (3-4 shots) (2) Injection of Ne to achieve Prad,main/PIN= 0.5. (J-bottom valve) (5 shots for scan of McPherson + 2-3 setup shots). (3) repeat (2) with Prad,main/PIN = 0.7 (5 shots). (4) Injection of Kr to evaluate relative effect on profiles (3 shots). (B-side lower). We may repeat steps 2 and 3 in Kr depending on results. Between shots without holding up sequence, pump out J-bottom and fill with N2 If time permits: (5) Injection of N to achieve Prad,main/PIN = 0.5. (J-bottom valve) (3 shots for scan of McPherson + 2-3 setup shots). (6) repeat (5) with Prad,main/PIN = 0.7 (5 shots).
Jan 9 1998 07:06:39:780AM		Steve Wolfe	OH test Shot is already loaded from last night. Do a coldstart. Got an A-matrix not responding error! Try coldstart again. 07:00 Bitbus log looks ok this time. No errors, all matrices respond. Hloader log looks ok.
Jan 9 1998 07:30:47:880AM		Steve Wolfe	While I'm waiting, put segment 4 back to a fiducial. Import segment 4 from 971217017. Check on the gain on BP12_DE in ZCUR predictor; it is -15e3, not enough to account for a significant error on ZCUR with a 25e-3 difference from BTOR offset between BP12_BC and BP12_DE. I suspect actual offsets in the iso-amps, some of which are larger than this; e.g. input 37 (BP08_BC) has a .1V (50mT) offset. These have drifted since the last campaign. We probably should retweak these, but then shots from the last month would need adjusting.
Jan 9 1998 08:18:28:720AM	980109001	Steve Wolfe	TF and OH2U Get a 20V amplitude (40V p-p) at the low frequency, dying off at the higher frequency. Next shot OH2L.
Jan 9 1998 08:37:01:470AM	980109001	Ian Hutchinson	Shot 1 oscillating OH2U shows no resonance. Gain is about 1.5 too high at lowest frequency. Roll off is quite rapid at the higher frequency. 3db point seems about .4s which is around 90Hz. It should not be so fast so soon. For some reason that chirp is going to 200 Hz.
Jan 9 1998 08:44:55:270AM	980109002	Ian Hutchinson	OH2L seems to have a slight resonance at the lower end of the frequency range. Not very severe. We realize that the expression we were using was not correct for what we had wanted. Still it gives us roughly a reasonable test.
Jan 9 1998 08:56:32:880AM	980109002	Steve Wolfe	Shot 2: TF and OH2L May show a small resonance arounf .1 sec (near 50Hz)
Jan 9 1998 08:51:10:600AM	980109003	Steve Wolfe	shot 3: TF and OH1 seems to roll off much faster, and has some similar oscillations before t=0.
Jan 9 1998 08:56:24:040AM	980109003	Ian Hutchinson	OH1 seems to roll off faster than the OH2s.
Jan 9 1998 09:01:55:310AM	980109004	Steve Wolfe	shot 4: TF and both OH2's. Change chirp to 20Hz: 80Hz. Note that previous expression was wrong, got to 200Hz. Now using _s = sin($2pi(20.+30_t)*_t) to get top frequency of 80Hz No apparent resonance in that. It looks like they are pretty linear.
Jan 9 1998 09:03:12:710AM	980109004	Ian Hutchinson	Slowed down the chirp to 20-60Hz. Ran OH2U/L simultaneously. No signs of anything bad happening.
Jan 9 1998 09:23:19:040AM	980109005	Steve Wolfe	Shot 5: Begin plasma run Load startup from 980107025. Copy TF waveform from seg 2 to seg 1 Turn on seg 2 ECE, pcx, moly monitor and VUV gate valves open. RF will try for 1.5MW this shot (wake up call) plasma full length. Long EDA H-mode. Startup looks good. 145kJ, H=1.7, Prf=1.7MW
Jan 9 1998 09:52:48:160AM	980109007	Steve Wolfe	Shot 6: repeat with more RF (we hope). Amanda is trying to get GPC back on the air; didn't show up on shot 5. fizzle. null looked bad on previous, and EF4's weren't cold. this time breakdown is a little late. EF4's still imbalanced (difference is positive); turns out the EF4U cryo valve wasn't open because of hysteresis. It was at -167, compared to -184 on lower. shot 7:When EF4U is down to -177 try again: another fizzle. balance is better, but not there yet. CII signal is up to .01. Br is still positive. Next shot, reduce Br offset.
Jan 9 1998 10:05:27:790AM	980109008	Steve Wolfe	Shot 8: Br offset from .006 to .0055 I suspect the real problem is dirt. CII iwas at .01 on shot 7, .008 on shot 6. plasma full length, still a big early marfe. EF4 balance to 0. now. CII down to .006 Got over 2MW RF, no H-mode during RF, H-mode after RF. H-alpha has a big flat enhancement.
Jan 9 1998 10:24:29:530AM	980109009	Steve Wolfe	Shot 9: repeat. plasma. full length, Looks like a good H-mode from TV. DAQA crashed right after shot, no data. For next shot, reduce TF current from 160->157kA. It was noted that on shot 8 we were at 5.8T instead of 5.7. Tom tried to recoverf the data from shot 9, but it is gone.
Jan 9 1998 10:34:44:900AM	980109010	Steve Wolfe	Shot 10: repeat with reduced TF current from 160->157kA. It was noted that on shot 8 we were at 5.8T instead of 5.7. . fizzle. EF4 imbalance down to -30A. CII at .008 again.
Jan 9 1998 10:43:26:310AM	980109011	Steve Wolfe	Shot 11: repeat with reduced TF current from 160->157kA. It was noted that on shot 8 we were at 5.8T instead of 5.7. . plasma. Looked on the TV like #9. Looks like a good EDA. Prf=2.2MW, W=147kJ. There still seems to be a problem with ECE calibration?
Jan 9 1998 10:56:08:680AM	980109012	Steve Wolfe	Shot 12: repeat, try for .4MW more RF. Note that CII was down to .004 on shot 11. plasma, 2.5MW, H-mode. 160kJ Next shot Neon
Jan 9 1998 11:07:43:660AM	980109013	Steve Wolfe	Shot 13: repeat with 20msec Ne pulse at 0.7sec plasma. H-mode. Only a small increase in 2pi signal
Jan 9 1998 11:23:59:510AM	980109014	Steve Wolfe	Shot 14: Delay Ne pulse to .85sec, increase to 30msec fizzle. CII at .006, bd a little late (6.3msec) Br maybe a little positive. Just try again.
Jan 9 1998 11:27:34:940AM	980109015	Steve Wolfe	Shot 15: repeat Delay Ne pulse to .85sec, increase to 30msec another fizzle. Try some tweaks.
Jan 9 1998 11:33:51:590AM	980109015	Steve Wolfe	Shot 15: repeat Delay Ne pulse to .85sec, increase to 30msec another fizzle. CII is down to .003, it isn't that. bd at .005, nice and early. Br looks a little negative, but null looks good. It got to 40kA and hit something. Looks to me like Bz isn't coming in fast enough.
Jan 9 1998 11:51:30:530AM	980109016	Steve Wolfe	Shot 16: EF4 from -1345->-1330 Delay Ne pulse to .85sec, increase to 30msec plasma. H-mode; I doubt that the EF4 tweak did it, though. Nice current rise; it's at 55ka at 15msec, with Bz of .007. bd is actually later, 6.8msec. I still am not happy with the startup. I may want to tweak the RCUR offset. Got more Ne this time, about 200kW on the 2pi. Start the scan, TF waggle on next shot.
Jan 9 1998 11:56:50:100AM	980109017	Steve Wolfe	Shot 17: TF waggle at 1.0sec to -164500kA. No startup tweak this time. fizzle, should have tweaked.
Jan 9 1998 12:14:20:240PM	980109018	Steve Wolfe	Shot 18: RCUR offset in segment 1 to 7000 TF waggle at 1.0sec to -164500kA. plasma, H-modes, etc. When it goes it goes. field in somewhat faster, 10mT @15msec. Little drop in neutron rate and Halpha at peak of radiation.
Jan 9 1998 12:27:07:750PM	980109019	Steve Wolfe	shot 19: repeat plasma. breakdown is later.
Jan 9 1998 12:37:25:210PM	980109020	Steve Wolfe	shot 20: Move TF waggle to .73 sec Seg 1 RCUR offset from 7000 to 8000 plasma, H-modes Next shot more Neon.
Jan 9 1998 12:57:17:010PM	980109021	Steve Wolfe	shot 21: INcrease neon pulse width to 60msec. Bring EF4 back to -1345A plasma. bd earlier 5.8msec, but a slight hesitation. Two EDA periods this time. Big injection at .93
Jan 9 1998 01:10:10:510PM	980109022	Steve Wolfe	shot 22: EF4 to -1335; move TF waggle back to 1sec fizzle. hesitation seemed to get it, even though I went part way back. Br is positive again. bd is later 8msec.
Jan 9 1998 01:16:26:330PM	980109023	Steve Wolfe	shot 23: EF4 to -1330; That should be essentially no change, but back to a setting that ran. TF waggle at 1sec fizzle.
Jan 9 1998 01:35:36:350PM	980109024	Steve Wolfe	shot 24: Br offset from .0055 to .005 TF waggle at 1sec plasma. bd is even later 7.5msec, br is almost unchanged except for a thrash at 3msec. Radiated power is up, no injection this time.
Jan 9 1998 01:56:03:990PM	980109025	Steve Wolfe	shot 25: Need more radiation. Move Neon pulse to 0.8 sec and turn on for 100msec plasma, ends a bit earlier in rampdown 1.38sec bd slightly earlier. Still a big Br jump around 3msec. Neon puff drops the halpha, 2MW of Prad. Clear change in Halpha, lower stored energy
Jan 9 1998 02:03:05:620PM	980109026	Steve Wolfe	shot 26: Need still more radiation. Move Neon pulse to 0.8 sec and turn on for 150msec dud EF3 breaker pulled before shot. EF3 had 4KA of induced current at t=0.
Jan 9 1998 02:24:37:950PM	980109027	Steve Wolfe	shot 27: Repeat try with 150msec Ne puff. plasma. 1.33sec Almost completely suppresses the EDA Halpha level, got an ELM at 1.03 sec bd at 6.3msec, rise is ok. For some reason, the last point on the EF4 flattop was at -.003 sec, but at some point today I've moved it to t=0. Hard to believe this matters, but it may be related to the Br thrash at +3msec. Don't do amything about it now. Wait till a fizzle.
Jan 9 1998 02:33:54:780PM	980109028	Steve Wolfe	shot 28: move Ne puff to 750msec, width 140ms plasma . Almost identical. bd back to 7.2msec, no hesitation. Leave it be. Next shot no neon
Jan 9 1998 02:46:30:590PM	980109029	Steve Wolfe	shot 29: Turn off J-bottom. No neon. plasma back to 1.6sec length Big injection at 1.05sec
Jan 9 1998 03:11:47:150PM	980109030	Steve Wolfe	shot 30: Krypton B-side lower pulse at .8 sec for 50msec disrupts just into ranpdown. Lost the H-mode at .87sec bolo gets to 3MW.
Jan 9 1998 03:27:12:470PM	980109031	Steve Wolfe	shot 31: Shorten Kr puff to 35msec. Change TF sweep to up and down +/- 4kA, still starting at 1.0sec plasma to 1.36sec. Long delay before L-H at .87 sec, then very ELMy. Initial Halpha seems to follow RF, similar to shot 8
Jan 9 1998 03:39:32:770PM	980109032	Steve Wolfe	shot 32: No changes, let the plasma adapt? plasma to 1.4sec, One transmitter shut off early. goes into H-mode promptly, but density turns over at .87, H-L at .918
Jan 9 1998 03:55:06:670PM	980109033	Steve Wolfe	shot 33: Reduce Kr to 20msec, extend reverse sweep on TF to 1.15sec plasma to 1.46,; Kr must be going away. Late L-H again.
Jan 9 1998 04:10:43:100PM	980109034	Steve Wolfe	shot 34: Repeat it like this. Disrupted early at .3sec. Looks like multiple bricks. 2pi goes to 8MW
Jan 9 1998 04:22:38:870PM	980109035	Steve Wolfe	shot 35: Move TF ramp to 0.9sec and make it unipolar again (157 to 164.5kA) in 100msec plasma to 1.5sec L-H at .72sec, start to lose EDA at .86, ELM or H-L at 1.00, second h-mode at 1.02 Next shot turn off TF sweep.
Jan 9 1998 04:34:14:370PM	980109036	Steve Wolfe	shot 36: Turn off TF ramp and Kr puff. plasma to 1.63 sec, long EDA 2pi at 800kW, 147kJ Next shot reduce Kr plenum pressure to 1.9psi and turn on the 20msec puff again
Jan 9 1998 04:51:21:500PM	980109037	Steve Wolfe	shot 37: 20msec Kr puff @1.9psi in plenum (was 4) at .8sec plasma to 1.57sec, long EDA, H-alpha starts dropping ELmy behavior aroumd 1.08, followed by short RF trip. Stored energy starts at 155kJ, drops linearly to 117 by end of RF pulse. bolo goes to 2.8MW Tfsweep back on next shot.
Jan 9 1998 05:09:14:540PM	980109038	Steve Wolfe	shot 38: 20msec Kr puff @1.9psi in plenum (was 4) at .8sec TF sweep starting at 0.9sec plasma to 1.54sec one long EDA, similar to 37 stored energy is down all the way through, dropping to 119kJ Two injections early in RF pulse. bolo ends up at 2.2MW prad.

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	08:13:48:570AM	Test	Ok
2	08:32:53:260AM	Test	Ok
3	08:48:24:180AM	Test	Ok
4	08:58:11:960AM	Test	Ok
5	09:14:21:620AM	Plasma	Ok
6	09:30:57:770AM	Plasma	Ok
7	09:44:25:420AM	Plasma	Ok
8	09:54:29:850AM	Plasma	Ok
9	10:08:21:770AM	Plasma	Bad	computer crash
10	10:26:53:090AM	Plasma	Ok
11	10:35:48:350AM	Plasma	Ok
12	10:49:16:490AM	Plasma	Ok
13	11:00:25:940AM	Plasma	Ok
14	11:17:22:950AM	Plasma	Ok
15	11:26:02:750AM	Plasma	Ok
16	11:37:29:380AM	Plasma	Ok
17	11:55:28:280AM	Plasma	Ok
18	12:04:28:840PM	Plasma	Ok
19	12:18:37:330PM	Plasma	Ok
20	12:32:36:660PM	Plasma	Ok
21	12:48:19:360PM	Plasma	Ok
22	01:03:22:590PM	Plasma	Ok
23	01:14:57:940PM	Plasma	Ok
24	01:27:50:180PM	Plasma	Ok
25	01:44:25:980PM	Plasma	Ok
26	01:58:50:190PM	Plasma	Ok
27	02:14:38:440PM	Plasma	Ok
28	02:28:02:370PM	Plasma	Ok
29	02:40:36:730PM	Plasma	Ok
30	03:00:36:720PM	Plasma	Ok
31	03:18:18:540PM	Plasma	Ok
32	03:31:56:030PM	Plasma	Ok
33	03:47:40:220PM	Plasma	Ok
34	04:05:36:050PM	Plasma	Ok
35	04:14:46:710PM	Plasma	Ok
36	04:26:41:560PM	Plasma	Ok
37	04:41:55:420PM	Plasma	Ok
38	04:56:29:960PM	Plasma	Ok