Alcator C-Mod Run 990205 Information

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Miniproposals
Miniproposal:211
Date Filed: 1/4/1999
Title:Constant shots to calibrate McPherson and HIREX Spectrometers
First Author:Jim Terry
Session Leader:Jim Terry (shots 1-28)

Operators
Session leader(s):Jim Terry
Physics operator(s):Joseph Snipes
Engineering operator(s):Frank Silva

Engineering Operator Run Comment
Snipe/Terry/Silva

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:18:947PM
Author: To Be Determined
The purpose of this run (and Tuesday's run) is to
calibrate McPherson and HIREX Spectrometers as
detailed in MP No. 211 " Constant shots to calibrate
McPherson and HIREX Spectrometers".

We started with shot 990203015, with same Ar puff,
but added an additional He puff starting at
0.65 s (on some early shots this puff started at 0.7 s.)

After shot 008 the shots were kept as constant as possible.

RF ran from 1.0 sec to 1.2 sec at 2.5 MW for most of the day.
During RF, H/D ratio was pushed up more than without RF,
but only a few percent (about 5% more than usual at that time in the shot).
We had no H-modes, probably because the H/D ratio was too high. It was
always >15% during the RF pulse.

The sensitivity of the McPherson spectrometer is calibrated
using the so-called branching ratio technique. This relies on
observation along the same line-of-sight of two spectral lines
originating from the same upper state, one in the VUV and
one in the visible. The intensity ratio of such a
pair of line can be calculated quite accurately.
Thus a calibration in the visible is to be transferred to
the VUV. The line pairs we used in today's run were:

D_0 1025 A (Ly_beta) & 6563 A (D_alpha)
D_0 972 A (Ly_gamma) & 4861 A (D_beta)
He_0 537 A & 5016 A
He+ 247 A (Ly_gamma) & 4686 A (Paschen_alpha)
He+ 256 A (Ly_beta) & 1640 A (Balmer_alpha)

Since there is so much Carbon in the machine,
we also tried

CIV 312 A & 5801+5812 A

The identification of the weak visible lines 5801, 5812 A
in the Chromex spectrum is shakey, but there appears to be something there.
The McPherson calibration is about 50% complete.

For HIREX the views, relative sensitivities, and instrumental
spectral resolutions of each of five spectrometers was
calibrated. This was done by having pairs of spectrometers
view Ar lines from the same plasma region. In addition the
pairs' views are scanned as much as possible so that
the entire poloidal cross-section can be covered by the
combination of all five spectrometers. About 60% of this calibration
work was completed.

A shot-by-shot account follows:

003 Good shot - saw He puff with McP at .73 s. Divertor appears to detach at 1 s
004 Good shot - saw He puff with McP and Chromex at .73 s.
005 Good shot - McP and Chromex looking at HeI
006 Good shot - McP and Chromex looking at HeI
007 Disrupted at 0.64 s
008 Good shot - Start constant shots - McP and Chromex looking at HeI
009 Good shot - McP and Chromex looking at HeII
010 Good shot - McP and Chromex looking at HeII
011 Good shot - McP on 1640 A (barely saw it) and Chromex looking at HeII
012 Good shot - McP had data problem, Chromex looking at HeII
013 Good shot - McP had data problem, Chromex looking at HeII
014 Good shot - McP had data problem, Chromex looking at HeII
015 Good shot - McP had data problem, Chromex looking at HeII
016 Good shot - McP had data problem, Chromex looking at HeII
017 Good shot - McP now fixed - looking at D_0 - Chromex looking at D_beta in divertor
018 Good shot - McP looking at D_0 - Chromex looking at D_beta in divertor
019 Disrupted at 0.256 s
020 Disrupted at 0.137 s
021 Good shot - McP looking at D_0 - Chromex looking at D_beta in divertor
022 Good shot - McP looking at D_0 - Chromex looking at D_beta in midplane
023 Good shot - McP looking at CIV -312 A, Chromex looking for 5801, 5812 in divertor
024 Good shot - McP looking at CIV -312 A, Chromex looking for 5801, 5812 in divertor
025 Good shot - McP and Chromex looking at HeII in divertor
026 Good shot - McP HV tripped, Chromex looking at HeII in divertor
027 Good shot - McP on 1640 A (barely saw it) and Chromex looking at HeII
028 Disrupted at 0.88 s - McP on 1640 A (barely saw it) and Chromex looking at HeII

Physics Operator Summaries
Entered: Jul 7 2004 04:37:00:003PM
Author: To Be Determined
Physop Summary for 990205 MP 211 McPherson,HiRex* Calibrations
Physop: Joseph Snipes
Session Leader: Jim Terry
Engineer in charge: Frank Silva

Engineering Setup for Friday 990205

Load from 990203015

Overnight ECDC in D2

TF under hybrid control

Gas setup - fill B-top with 6 psi of D2 Hybrid enabled
fill B-side lower with 1 psi of Ar Hybrid enabled
fill B-side upper with 10 psi of He4 Hybrid enabled
fill C-side with 30 psi of D2 Hybrid enabled

The following gate valves should be enabled, assuming no vacuum problems:

ECE VUV

Start with shot 990203015, with same Ar puff, but with additional He puff
starting at 0.7 s. This puff should increase NL_04 to ~1.3e20 m^-2. This may
have to be fine tuned depending on the signals.

Once we agree that this is appropriate for the HIREX, the McPherson, and the
Chromex spectrometers, we will keep the shot essentially constant for the rest
of the run.

Overall, it was a very good run. We got 26 plasmas out of 28 shots. The first
two were "engineering test shots". Of the plasmas, four disrupted before ramp
down and all of the others disrupted in rampdown. So, there were 22 useful
full length discharges. J. T. will finish the calibrations on Tuesday.

Shot Summary:

Shot 1: Copied shot 990203015 and added a He4 puff at 100 V from 0.7 to 0.9 sec
Test shot to correct TMX error.
Shot 2: Only 3 power supplies fired. Others failed due to an engineering setup
problem.
Shot 3: Good shot.
Shot 4: Repeat. Good shot.
Shot 5: Added 5 msec to Ar puff, now from 0.30 - 0.336 sec. Changed density
feedback wire to TCI NL04 from the Zmeter. Good shot.
Shot 6: He4 puff starting at 0.65 instead of 0.7 and stopping at 0.9 sec.
Good shot.
Shot 7: Modified rampdown to reduce the elongation after 1.2 sec and push the
plasma against the inner wall to help pumpout the density before the
current gets too low to sustain the density. Disrupted at 0.62 sec due
to a Moly brick.
Shot 8: Try again with no changes. Good shot. Rampdown a little longer.
Shot 9: Modified the rampdown a little more to try to push the plasma against
the inner wall after 1.2 sec and reduce the elongation. Good shot.
Rampdown is not as good however. Disrupted at 1.3 sec.
Shot 10: Modified the rampdown again to try to keep the plasma elongated a
little longer into the rampdown to maintain a larger plasma while the
current is still relatively high. Good shot. Rampdown until about
1.37 sec when it disrupted at about 0.5 MA.
Shot 11: Modified rampdown a bit to try not to push the plasma against the wall
so strongly after 1.2 sec. Made more gradual changes in RCUR and
CLEARIN after 1.2 sec. Good shot.
Shot 12: Repeat. Good shot.
Shot 13: Modified rampdown again to try to maintain a large elongated plasma
well into the rampdown. Modified RCUR and CLEARIN to nearly maintain
the plasma shape well into the rampdown. Good shot.
Shot 14: Short cell opening to open up a cooling valve. Modified rampdown again
slightly. The plasma moves up well before the disruption on the
previous shots though ZCUR is programmed to be flat. Try keeping ZXU
and ZXL constant through the rampdown. Good shot.
Shot 15: J.T. went in to check something. Modified rampdown once again moving
RXU and RXL inward during the rampdown. Maybe the strike point in
the lower divertor is moving across some loaded surfaces and releasing
more gas into the plasma during rampdown. Good shot.
Shot 16: Modified rampdown again to keep CLEARIN and RCUR constant out to 1.5
sec. Good shot.
Shot 17: Moved RXL in by 3 cm after 1.2 sec to try to improve the rampdown.
Good shot. Rampdown looks better. Disrupts at 1.48 sec.
Shot 18: Modified rampdown some more moving RXU in after 1.2 sec and moving
ZXU and ZXL in toward the plasma center after 1.2 sec, which they were
doing anyway without programming them. Good shot.
Shot 19: Modified rampdown again moving CLEARIN and RCUR in by 0.5 - 1 cm after
1.2 sec and some more tweaks on the X point locations. Disrupted at
0.27 sec without clear precursors, probably a brick, though Rice sees
nothing on the HIREX signals. It was not vertically unstable.
Shot 20: Try again. Disrupted at 0.13 sec.
Shot 21: Repeat. Good shot. Good rampdown past 1.5 sec.
Shot 22: Modified rampdown a bit more reducing RCUR and CLEARIN to reduce the
inner gap by another 0.5 cm and moved in RXL and RXU by another 1 cm
after 1.2 sec. Good shot. Rampdown not as good as shot 21.
Shot 23: Copied shot 990205021 and then modified CLEARIN and RCUR only after
1.4 sec to try to make the rampdown last still longer. Good shot,
rampdown better than shot 21 out to 1.52 sec.
Shot 24: Modified rampdown again past 1.4 sec to try to make the rampdown last
longer still. Moved X points further in radially and vertically.
Good shot. Rampdown not quite as good as 23.
Shot 25: Returned to rampdown of shot 990205023 then modified rampdown
after 1.4 sec to try to force ZCUR down by 1 cm when it is trying to
go up. Good shot. Rampdown lasts to 1.5 sec.
Shot 26: Modified rampdown again moving X points in radially and vertically
after 1.4 sec. Also moved CLEARIN and RCUR in a bit after 1.4 sec.
Good shot. Rampdown until 1.51 sec.
Shot 27: Modified rampdown again moving ZCUR down another 1 cm after 1.4 sec
to attempt to compensate for the plasmas upward motion. Good shot.
Rampdown the same.
Shot 28: Increased EF4U current after 1.25 sec to try to keep it away from
cross-over at the disruption. Disrupted at 0.89 sec. There was also
a bite out of the current around 0.4 sec.
There was an intentional impurity injection (Au) at 0.25 sec.

Shot,Duration(s),Ipmax(MA) Shot,Duration(s),Ipmax
1 0.000 0.005 2 0.000 0.007
3 1.380 0.812 4 1.389 0.817
5 1.413 0.812 6 1.418 0.812
7 0.645 0.812 8 1.484 0.817
9 1.332 0.812 10 1.381 0.812
11 1.427 0.817 12 1.434 0.820
13 1.423 0.823 14 1.423 0.818
15 1.447 0.820 16 1.435 0.818
17 1.485 0.820 18 1.492 0.817
19 0.261 0.688 20 0.141 0.425
21 1.518 0.820 22 1.427 0.812
23 1.535 0.812 24 1.518 0.820
25 1.511 0.812 26 1.518 0.812
27 1.520 0.817 28 0.896 0.869

Finished summary for 990205 Total of 28 shots.
28 shots. 26 plasmas. 0 fizzles. 2 tests.



Session Leader Comments
Feb 5 1999 09:24:44:060AMJim TerryThe purpose of this run (and Tuesday's run) is to
calibrate McPherson and HIREX Spectrometers as
detailed in MP No. 211 " Constant shots to calibrate
McPherson and HIREX Spectrometers".

We will start with shot 990203015, with same Ar puff,
but with additional He puff starting at
0.7 s. This puff should increase NL_04 to
~1.3e20 m^-2. This may have to be fine
tuned depending on the signals.

Once we agree that this is appropriate
for the HIREX, the McPherson, and
the Chromex spectrometers, we will keep the
shot essentially constant for the rest of the
run.


The sensitivity of the McPherson spectrometer is calibrated
using the so-called branching ratio technique. This relies on
observation along the same line-of-sight of two spectral lines
originating from the same upper state, one in the VUV and
one in the visible. The intensity ratio of such a
pair of line can be calculated quite accurately.
Thus a calibration in the visible can be transferred to
the VUV. The line pairs we have used in the
past have been:

D_0 1025 A (Ly_beta) & 6563 A (D_alpha)
D_0 972 A (Ly_gamma) & 4861 A (D_beta)
D_0 950 A (Ly_delta) & 4340 A (D_gamma)
He_0 537 A & 5016 A
He+ 247 A (Ly_gamma) & 4686 A (Paschen_alpha)
He+ 253 A (Ly_beta) & 1640 A (Balmer_alpha)

Since there is so much Carbon in the machine,
we will also try

CIV 312 A & 5801+5812 A

For HIREX the views, relative sensitivities, and instrumental
spectral resolutions of each of five spectrometers must be
calibrated. This is done by having pairs of spectrometers
view Ar lines from the same plasma region. In addition the
pairs' views are scanned as much as possible so that
the entire poloidal cross-section could be covered by the
combination of all five spectrometers.


Feb 5 1999 09:28:15:967AM990205003Jim TerryGood shot - saw He puff with McP at .73 s
Divertor detaches at 1 s
Feb 5 1999 09:52:49:170AM990205004Jim TerryGood shot - saw He puff with Chromex and McP at .73 s
RF ON at .9 s
Feb 5 1999 10:03:51:403AM990205005Jim TerryGood shot - saw He puff with Chromex and McP at .73 s
Chromex looking at 5016 A, McP Looking at HeI spectrum.
Chromex central wavelength was 5000 A
No RF
Feb 5 1999 10:13:22:903AM990205006Jim TerryGood shot - saw He puff with Chromex and McP at .73 s
Chromex looking at 5016 A, McP Looking at HeI spectrum.
Chromex central wavelength was 4860 A.
RF from 1 to 1.2 s
Feb 5 1999 10:24:37:793AM990205007Jim TerryDisrupted at 0.64 s - looks like a brick of something.
Feb 5 1999 10:48:40:467AM990205008Jim TerryGood shot - HIREX has started its scan, so
this is the constant shot we want to keep.
McP looking at 537 A - Chromex at 5016 A.
McP jack at 12.18.
Feb 5 1999 11:09:07:373AM990205009Jim TerryGood shot -
McP looking at 243 A - Chromex at 4686 A.
McP jack at 14.43.
Feb 5 1999 11:27:20:250AM990205010Jim TerryGood shot -
McP looking at 243 A and 256 A - Chromex at 4686 A.
McP jack at 14.43.
Feb 5 1999 11:46:33:607AM990205011Jim TerryGood shot -
McP looking at 1640 A (barely saw it) - Chromex at 4686 A.
McP jack at 14.43.
Feb 5 1999 12:19:54:733PM990205012Jim TerryGood shot -
McP had a HV problem - Chromex at 4686 A.
McP jack at 14.43.
Feb 5 1999 12:27:20:687PM990205013Jim TerryGood shot -
Again a HV problem on McP - Chromex at 4686 A.
McP jack at 14.43.
Feb 5 1999 12:45:03:733PM990205014Jim TerryGood shot -
HV trip on McP - Chromex at 4686 A.
McP jack at 14.43.
Feb 5 1999 01:48:28:170PM990205015Jim TerryGood shot -
McP has signal problem (electrical, not HV) - Chromex at 4686 A.
McP jack at 14.43.
Feb 5 1999 01:49:50:857PM990205016Jim TerryGood shot -
Had a cell access ot check detector wires on McP.
McP still has signal problem (electrical, not HV) - Chromex at 4686 A.
McP jack at 14.43.
Feb 5 1999 01:51:11:200PM990205017Jim TerryGood shot -
McP signal is back looking at Ly beta, gamma - Chromex at 4861 A.
McP jack at 14.43.
Feb 5 1999 01:58:34:763PM990205018Jim TerryGood shot -
McP looking at Ly beta, gamma - Chromex at 4861 A.
McP jack at 14.43.
Feb 5 1999 02:08:21:873PM990205019Jim TerryDirsupted at 0.256 s
Feb 5 1999 02:26:45:530PM990205020Jim Terrydisrupted at 0.137 s
Feb 5 1999 02:52:30:513PM990205021Jim TerryGood shot -
McP looking at Ly beta, gamma - Chromex at 4861 A.
McP jack at 14.43.
-
Feb 5 1999 03:00:47:920PM990205022Jim TerryGood shot -
McP looking at Ly beta, gamma - Chromex at 4861 A.
McP jack at 8.53.
-
Feb 5 1999 03:29:33:280PM990205023Jim TerryGood shot -
McP looking at CIV 312 A (see it well).
Chromex at 5800 A(marginal identification
of 5801 A and 5812 A doublet.
McP jack at 14.17.
-
Feb 5 1999 03:49:18:793PM990205024Jim TerryGood shot -
McP looking at CIV 312 A (see it well).
Chromex at 5800 A(marginal identification
of 5801 A and 5812 A doublet).
McP jack at 14.75.
-
Feb 5 1999 04:13:24:590PM990205025Jim TerryGood shot -
McP looking at He 243 and 256 A.
Chromex at 4686 A.
McP jack at 14.75.
-
Feb 5 1999 04:37:19:670PM990205026Jim TerryGood shot -
McP HV tripped.
Chromex at 4686 A.
McP jack at 14.75.
-
Feb 5 1999 04:43:24:000PM990205027Jim TerryGood shot -
McP HV looking at 1640 A (saw it).
Chromex at 4686 A.
McP jack at 14.75.
-
Feb 5 1999 05:14:11:750PM990205028Jim TerryDisrupted at 0.888 s
McP HV looking at 1640 A (saw it).
Chromex at 4686 A.
McP jack at 14.75.
-

Physics Operator Comments
Feb 5 1999 08:22:57:543AMJoseph SnipesEngineering Setup for Friday 990205

Load from 990203015

Overnight ECDC in D2

TF under hybrid control

Gas setup - fill B-top with 6 psi of D2 Hybrid enabled
fill B-side lower with 1 psi of Ar Hybrid enabled
fill B-side upper with 10 psi of He4 Hybrid enabled
fill C-side with 30 psi of D2 Hybrid enabled

The following gate valves should be enabled, assuming no vacuum problems:

ECE VUV

Start with shot 990203015, with same Ar puff, but with additional He puff
starting at 0.7 s. This puff should increase NL_04 to ~1.3e20 m^-2. This may
have to be fine tuned depending on the signals.

Once we agree that this is appropriate for the HIREX, the McPherson, and the
Chromex spectrometers, we will keep the shot essentially constant for the rest
of the run.
Feb 8 1999 02:57:56:530PMRobert GranetzEngineering Setup for Tuesday, 990209:

Load from 990205027

Overnight ECDC in D2

TF under hybrid control

Gas setup - fill B-top with 6 psi of D2 Hybrid enabled
fill B-side lower with 1 psi of Ar Hybrid enabled
fill B-side upper with 20 psi of He4 Hybrid enabled
fill C-side with 30 psi of D2 Hybrid enabled

The following gate valves should be enabled, assuming no vacuum problems:

ECE, VUV
Feb 8 1999 02:58:43:140PMRobert GranetzRun Plan for 990209:
-------------------------------------------------------------------------------

Start with shot 990205027, with same Ar and He valve programming, but with
twice the pressure in the He plenum.

Once we agree that this is appropriate for the HIREX, the McPherson, and the
Chromex spectrometers, we will keep the shot essentially constant for the rest
of the run.
Feb 5 1999 08:54:59:640AM990205001Joseph SnipesShot 1: Copied shot 990203015 and added a He4 puff at 100 V from 0.7 to 0.9 sec
Test shot to correct TMX error, no power supplies.
Feb 5 1999 09:00:25:890AM990205002Joseph SnipesShot 2: Only 3 power supplies fired. Others were off due to a setup problem.
Feb 5 1999 09:29:54:467AM990205004Joseph SnipesShot 3: Good shot.
Feb 5 1999 09:30:09:623AM990205004Joseph SnipesShot 4: Repeat. Good shot.
Feb 5 1999 10:05:05:700AM990205005Joseph SnipesShot 5: Added 5 msec to Ar puff, now from 0.30 - 0.336 sec. Changed density
feedback wire to TCI NL04 from the Zmeter. Good shot.
Feb 5 1999 10:03:44:233AM990205006Joseph SnipesShot 6: He4 puff starting at 0.65 instead of 0.7 and stopping at 0.9 sec.
Good shot.
Feb 5 1999 10:24:12:390AM990205007Joseph SnipesShot 7: Modified rampdown to reduce the elongation after 1.2 sec and push the
plasma against the inner wall to help pumpout the density before the
current gets too low to sustain the density. Disrupted at 0.62 sec due
to a Moly brick.
Feb 5 1999 10:40:18:107AM990205008Joseph SnipesShot 8: Try again with no changes. Good shot. Rampdown a little longer.
Feb 5 1999 10:59:37:590AM990205009Joseph SnipesShot 9: Modified the rampdown a little more to try to push the plasma against
the inner wall after 1.2 sec and reduce the elongation. Good shot.
Rampdown is not as good however. Disrupted at 1.3 sec.
Feb 5 1999 11:25:19:840AM990205010Joseph SnipesShot 10: Modified the rampdown again to try to keep the plasma elongated a
little longer into the rampdown to maintain a larger plasma while the
current is still relatively high. Good shot. Rampdown until about
1.37 sec when it disrupted at about 0.5 MA.
Feb 5 1999 11:49:43:000AM990205011Joseph SnipesShot 11: Modified rampdown a bit to try not to push the plasma against the wall
so strongly after 1.2 sec. Made more gradual changes in RCUR and
CLEARIN after 1.2 sec. Good shot.
Feb 5 1999 11:54:34:090AM990205012Joseph SnipesShot 12: Repeat. Good shot.
Feb 5 1999 12:18:32:983PM990205013Joseph SnipesShot 13: Modified rampdown again to try to maintain a large elongated plasma
well into the rampdown. Modified RCUR and CLEARIN to nearly maintain
the plasma shape well into the rampdown. Good shot.
Feb 5 1999 12:48:26:310PM990205014Joseph SnipesShot 14: Short cell opening to open up a cooling valve. Modified rampdown again
slightly. The plasma moves up well before the disruption on the
previous shots though ZCUR is programmed to be flat. Try keeping ZXU
and ZXL constant through the rampdown. Good shot.
Feb 5 1999 01:06:07:500PM990205015Joseph SnipesShot 15: J.T. went in to check something. Modified rampdown once again moving
RXU and RXL inward during the rampdown. Maybe the strike point in
the lower divertor is moving across some loaded surfaces and releasing
more gas into the plasma during rampdown. Good shot.
Feb 5 1999 01:21:17:670PM990205016Joseph SnipesShot 16: Modified rampdown again to keep CLEARIN and RCUR constant out to 1.5
sec. Good shot.

Feb 5 1999 01:31:38:373PM990205017Joseph SnipesShot 17: Moved RXL in by 3 cm after 1.2 sec to try to improve the rampdown.
Good shot. Rampdown looks better. Disrupts at 1.48 sec.
Feb 5 1999 01:41:12:513PM990205017Joseph SnipesShot 17: Moved RXL in by 3 cm after 1.2 sec to try to improve the rampdown.
Good shot. Rampdown looks better. Disrupts at 1.48 sec.
Feb 5 1999 01:57:26:107PM990205018Joseph SnipesShot 18: Modified rampdown some more moving RXU in after 1.2 sec and moving
ZXU and ZXL in toward the plasma center after 1.2 sec, which they were
doing anyway without programming them. Good shot.
Feb 5 1999 02:17:24:340PM990205019Joseph SnipesShot 19: Modified rampdown again moving CLEARIN and RCUR in by 0.5 - 1 cm after
1.2 sec and some more tweaks on the X point locations. Disrupted at
0.27 sec without clear precursors, probably a brick, though Rice sees
nothing on the HIREX signals. It was not vertically unstable.
Feb 5 1999 02:25:02:560PM990205020Joseph SnipesShot 20: Try again. Fizzle!
Feb 5 1999 02:55:04:107PM990205020Joseph SnipesShot 20: Try again. Disrupted at 0.13 sec.
Feb 5 1999 02:55:28:170PM990205021Joseph SnipesShot 21: Repeat. Good shot. Good rampdown past 1.5 sec.
Feb 5 1999 03:09:28:043PM990205022Joseph SnipesShot 22: Modified rampdown a bit more reducing RCUR and CLEARIN to reduce the
inner gap by another 0.5 cm and moved in RXL and RXU by another 1 cm
after 1.2 sec. Good shot. Rampdown not as good as shot 21.
Feb 5 1999 03:23:35:420PM990205023Joseph SnipesShot 23: Copied shot 990205021 and then modified CLEARIN and RCUR only after
1.4 sec to try to make the rampdown last still longer. Good shot,
rampdown better than shot 21 out to 1.52 sec.
Feb 5 1999 03:48:36:560PM990205024Joseph SnipesShot 24: Modified rampdown again past 1.4 sec to try to make the rampdown last
longer still. Moved X points further in radially and vertically.
Good shot. Rampdown not quite as good as 23.
Feb 5 1999 03:58:44:030PM990205025Joseph SnipesShot 25: Returned to rampdown of shot 990205023 then modified rampdown
after 1.4 sec to try to force ZCUR down by 1 cm when it is trying to
go up. Good shot. Rampdown lasts to 1.5 sec.
Feb 5 1999 04:28:58:687PM990205026Joseph SnipesShot 26: Modified rampdown again moving X points in radially and vertically
after 1.4 sec. Also moved CLEARIN and RCUR in a bit after 1.4 sec.
Good shot. Rampdown until 1.51 sec.
Feb 5 1999 04:50:16:233PM990205027Joseph SnipesShot 27: Modified rampdown again moving ZCUR down another 1 cm after 1.4 sec
to attempt to compensate for the plasmas upward motion. Good shot.
Rampdown the same.
Feb 5 1999 04:57:59:123PM990205028Joseph SnipesShot 28: Increased EF4U current after 1.25 sec to try to keep it away from
cross-over at the disruption. Disrupted at 0.89 sec. There was also
a bite out of the current around 0.4 sec.
Feb 5 1999 05:00:48:000PM990205028Joseph SnipesShot 28: There was an intentional impurity injection (Au) at 0.25 sec.
Feb 8 1999 09:31:22:090AM990205028Joseph SnipesOverall, it was a very good run. We got 26 plasmas out of 28 shots. The first
two were "engineering test shots". Of the plasmas, four disrupted before ramp
down and all of the others disrupted in rampdown. So, there were 22 useful
full length discharges. J. T. will finish the calibrations on Tuesday.

Engineering Operator Comments
ShotTimeTypeStatusComment
108:45:42:340AMPlasmaOko22 comm bank no charge p.s. off
208:55:40:090AMPlasmaOkcontrol panel did not turn all supplies on
309:02:59:437AMPlasmaOkno faults/plasma
409:21:19:623AMPlasmaOkno faults/plasma
509:42:35:060AMPlasmaOkno faults/plasma
609:59:42:590AMPlasmaOkno faults/plasma
710:17:24:013AMPlasmaOkno faults/plasma
810:35:38:653AMPlasmaOkno faults/plasma
910:56:12:623AMPlasmaOkno faults/plasma
1011:15:12:543AMPlasmaOkno faults/plasma
1111:34:25:543AMPlasmaOkno faults
1211:53:08:217AMPlasmaOkno faults
1312:14:01:810PMPlasmaOkno faults/plasma
1412:32:06:293PMPlasmaOkno faults/plasma
1512:51:05:310PMPlasmaOkno faults
1601:09:35:670PMPlasmaOkno faults/plasma
1701:27:41:000PMPlasmaOkno faults/plasma
1801:46:32:200PMPlasmaOkno faults/plasma
1902:05:06:030PMPlasmaOkno faults/fizzel
2002:23:20:543PMPlasmaOkno faults/plasma
2102:39:20:810PMPlasmaOkno faults/plasma
2202:57:22:060PMPlasmaOkno faults/plasma
2303:15:26:263PMPlasmaOkno faults/plasma
2403:36:53:950PMPlasmaOkno faults/plasma
2503:55:45:357PMPlasmaOkno faults/plasma
2604:15:26:357PMPlasmaOkno faults/plasma
2704:34:53:340PMPlasmaOkno faults
2804:54:24:403PMPlasmaOkno faults/plasma