Alcator C-Mod Run 990416 Information

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Miniproposals
Miniproposal:221a
Date Filed: 3/12/1999
Title:Experimental study of Zeeman effect influence on opacity
First Author:Xavier Bonnin
Session Leader:Jim Terry (shots 1-25)

Operators
Session leader(s):Jim Terry
Physics operator(s):Robert Granetz
Engineering operator(s):Frank Silva

Engineering Operator Run Comment
MP 221A/Granetz/Silva

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:20:163PM
Author: To Be Determined
The purpose of the first half of the 990416 run is detatiled in MP 221A.
Briefly it is to vary the opacity of the D_0 Lyman lines by changing
the magnetic field strength, thereby changing the Zeeman splitting of
the lines, thereby possibly affecting the opacity.

The plan was to

1) Make a (diverted) plasma (load shot 990331029).

2) Make a reproducible, inner wall-limited plasma with a stable
midplane MARFE (we may need to induce the MARFE by a D_2 gas puff
from the midplane NINJA capillary (Load shot 980210035, starting with I_p at 800 kA,
but with no loop voltage modulation.)
If we get this discharge at 800 kA then we will drop the plasma current
to 600 kA.

3) ramp the toroidal field from 5.4 T down to 2.7 T, with the ramp starting
at ~ 0.6 s, ie ~200 ms after the MARFE developes. The B_t ramp rate should be
as fast as possible. q_95 will go from ~5.6 at 5.4 T to 2.8 at 2.7 T.

4) We will run this shot until we have a data set from all the spectroscopic
diagnostics (VUV, Chromex, U Md spectrometer, H/D ratio, reticons).

5) If time permits, we want to make a stable midplane MARFE in a DIVERTED
magnetic configuration. To do this we want to load segment 1
from shot 980122038 for the gas programming and
segment 2 from 990331029. (Start at 800 kA. If OK, then drop I_p to 600 kA.)

6) After obtaining a midplane MARFE, we will again ramp B_t down to 2.7 T.

For this run we will puff D_2 from capillary B16-001 of the NINJA system.
GPC 2 will be set up to give temperature profiles
at 5.4 T, while GPC 2 will give profiles at the 2.6 T field.

We were partially successful in goals 1, 2, 3, and 4. We did not
do goals 5 or 6.

The major results were:

1) Shot 990416019 was the best shot as regards the goals of this MP.
There was full coverage of the inner wall by the Chromex. McPherson
was looking at Ly_beta thru Ly_8 from the relatively stable
MARFE located at Z=-0.12 m. B_t ramped from 5.4 T to 3.24 T
before the plasma disrupted at 0.9 s. Very preliminary analysis
shows no obvious change in the Ly_beta/D_alpha ratio, which would be the
signature of a changing Ly_beta opacity. Obviouly more detailed
analysis is necessary.

2) We also found that the NINJA midplane puff did not really affect
the vertical position of the inner wall MARFE, whose position seems
to depends on parameters presently unknown. The MARFE tended to ride
well below the point of contact on the inner wall.

3) We observed an interesting effect using the D_alpha-, D_gamma-
filtered TV cameras looking at the inner wall at the midplane.
The plume from the NINJA capillary switches directions (toroidally)
depending on whether the MARFE is above or below the capillary.


A detailed shot list follows:

Shots 001-005 magnet/power supply tests
006 Good shot - diverted (I_p = 800 kA)
007 Good shot - limited, MARFE somewhat below the midplane, starting at ~.15 s
008 Went to 600 kA - I_p, lost TCI at 0.226 s, disrupted (slowly) at 0.628 s
No NINJA puff on that shot.
009 Good shot, 600 kA - I_p, no NINJA puff, MARFE well below the midplane
010 Good shot, 600 kA - I_p, no NINJA puff, MARFE still well below the midplane
011 fizzle
012 Good shot, 600 kA - I_p, MARFE still well below the midplane, still no NINJA
013 Good shot, 600 kA - I_p, MARFE still well below the midplane
we saw the NINJA puff (start at .4, on for .5 at 470 T), but it
was small emission relative to the MARFE and did not raise the
position of the MARFE
014 Good shot, 600 kA - I_p, slow disruption starting at 1.0s.
We programmed B_t to ramp from 5.4 to 2.7 T (ramp starting
at .5 s ending at .9 s). The MARFE is now on the midplane.
We saw the NINJA puff (start at .4, on for .5 at 470 T), but it
was still small emission relative to the MARFE.
015 OK shot, 600 kA - I_p, slow disruption starting at 0.86s,
probably caused by a CaF_2 injection. We ramped B_t down from 5.4 T
The MARFE moves off of the midplane after ~0.5 s. We saw the NINJA
puff (start at .4, on for .5 at 470 T).
016 Good shot, 600 kA - I_p. We ramped B_t down from 5.4 to 2.7 T.
The MARFE is on the midplane but disappears after ~0.5 s. No NINJA.
017 Good shot, 600 kA - I_p, disrupted at 1.09 s.
B_t ramp. The MARFE moves off the midplane to ~-0.12 m. No NINJA.
018 fizzle
019 Best shot for MARFE study. There was full coverage of the inner wall
by the Chromex. McP looking at Ly_beta thru Ly_8 in the relatively stable
MARFE at Z=-0.12 m. B_t ramped to 3.24 T before the plasma disrupted at 0.9 s.
020 Back to good diverted 800 kA shot. Turned the run
over to Brian Labombard for burping probe studies.

Physics Operator Summaries
Entered: Jul 7 2004 04:37:00:787PM
Author: To Be Determined
Physics operator summary for run 990416.

MP 221A -- Experimental study of Zeeman effect influence on opacity
MP 222 -- Impurity compression and enrichment studies

SL: J. Terry, J. Goetz
PO: R. Granetz

The goals for today:

(1) The purpose of the first half of the day (MP 221A) is to vary the
opacity of the D_0 Lyman lines by changing the magnetic field strength,
thereby changing the Zeeman splitting of the lines. Inboard limited
plasmas will be tried first in order to get bright marfes at the
midplane.

(2) During the second half of the day (MP 222), the density will be varied,
as will the bypass position (open vs closed). The screening,
compression, and enrichment of impurities (Kr, Ar) will be measured.

Summary: Although Jim Terry and Brian Labombard were able to salvage some
physics from this run, it did not go very smoothly, even though the
tokamak itself ran well. The two primary problems were (1) the TCI
interferometer system was unreliable for most of the day, and we
therefore ran with pre-programmed valve voltage only, and (2) the
inner-wall marfe would not stay on the midplane, and actually was
well below the midplane most of the time. These problems, plus some
ICRF debugging, resulted in numerous cell accesses, costing us several
hours in toto. Due to the lack of the TCI data, the second MP was
not attempted. Brian Labombard got the last few shots for initial
tests of ethylene (i.e. carbon) plumes.

Shot 4 was a good TF-only shot at 5.7 T with 1.4 second flattop for
use in calibrating the magnetics.

Scorecard: 16 plasmas
5 fizzles
0 duds (0 due to power supply faults)
4 tests
----------
25 total

------------------------------------------------------------------------------
Engineering Setup for Friday, 990416

Load from 990331029

Overnight ECDC in D2, stopping in time to begin run at 08:00.

---> *** TF under PLC control initially ***

Gas setup - fill B-top with 6 psi of D2 Hybrid enabled
fill B-side lower with 1 psi of Ar Hybrid DISABLED
fill B-side upper with 2 psi of Kr Hybrid DISABLED
fill C-side with 30 psi of D2 Hybrid enabled
leave J-bottom as is Hybrid DISABLED

fill NINJA with 22 psi of D2

(Later in the day we may want to refill the NINJA with ethylene.)

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

ECE, VUV

-------------------------------------------------------------------------------
Run Plan for 990416 (2 half-day miniproposals):

MP 221A -- Experimental study of Zeeman effect influence on opacity
MP 222 -- Impurity compression and enrichment studies

The purpose of the first half of the day (MP 221A) is to vary the
opacity of the D_0 Lyman lines by changing the magnetic field
strength, thereby changing the Zeeman splitting of the lines.
Inboard limited plasmas will be tried first in order to get bright marfes at
the midplane.

During the second half of the day (MP 222), the density will be varied, as will
the bypass position (open vs closed). The screening, compression, and
enrichment of impurities (Kr, Ar) will be measured.

Before the physics runs, we will need to do three test shots:

1) Usual 'Tuesday' OH test.
2) TF only test, 50 kA, 1 sec flattop (PLC control, disable fizzle detector)
3) TF only test, 150 kA, 1 sec flattop (PLC control, disable fizzle detector)

After these initial tests:
For 1st MP, start from plasma shot 990331023.
For 2nd MP, start from plasma shot 990305023 (note the power supply settings
for this long shot).

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

Note: Overnight ECDC in D2 was done prior to this run.

Hybrid coldstart done; no errors found
($set default cmod$models:[hybrid.tcl]
$@hybinit_dispatch
$@show_bitbus_log
Use editor search to verify no occurrences of "error" nor
"not respond")
Load 990331023.
Confirm that RF feedback on RCUR is turned off (RF_LOAD_E = 0.0)

Shot 01 -- OH test. All OK.

Next shot: TF-only test at 50 kA, for approximately 1 s flattop.

Shot 02 -- TF-only test at 50 kA, for approximately 1 s flattop.

Next shot: TF-only test at 150 kA, for 1 s flattop (for magnetics
calibration.

Shot 03 -- TF-only test at 150 kA (for magnetics calibration). This was
supposed to have a 1 s flattop, but it only lasted until t=0.2 s.

Shot 04 -- TF-only test at 150 kA, this time with 1 s flattop (for magnetics
calibration). Actually got 161 kA (5.7 T) for 1.4 s flattop.

Next shot: plasma; load from 990331023 (0.8 MA, diverted)

Shot 05 -- Fizzle. BR had +2 mT offset.

Next shot: reduce BR offset by 2 mT (from 0.0045 to 0.0025 T), and
reduce pre-fill puff from 20 to 18 ms.

Shot 06 -- Plasma. Good shot. Ip=0.75 MA, Bt=5.4 T, nl_04=0.9e20 m-2.

Next shot: 0.8 MA limiter plasma. Load from 980210035, but remove
the modulation on the plasma current.

Shot 07 -- Plasma. Good limited shot at 0.77 MA, 5.4 T. Marfe on inboard
wall. nl_04=1.2e20 m-2.

Next shot: reduce Ip to 0.6 MA. Also, increase argon puff from 20
to 30 ms. Also NINJA D2 puffing at inboard midplane from t=0.50 for
duration of 0.15 s.

Cell access required for diagnostics purposes between shots 7 and 8.

Shot 08 -- Plasma. 0.6 MA. CO2 laser failed at 0.2 s, so we had no feedback
control of density. Discharge terminated slowly, ramping down over
0.2 s, to end at t=0.8 s. NINJA puffed D2 at inboard midplane.

Next shot: repeat, but with no NINJA puff. Lower NINJA plenum
pressure to 10 psi (from 22 psi).

Shot 09 -- Plasma. Good 0.6 MA, 5.4 T limited shot. Marfe on inboard wall,
below the midplane. nl_04=1.2e20 m-2.

Next shot: decrease elongation by raising ZXL by 1.5 cm and
lowering ZXU by 1.3 cm. Turn on NINJA from t=0.4 to 0.9 s (with
plenum pressure reduced from 22 to 10 psi).

Shot 10 -- Plasma. Good 0.6 MA, 5.4 T limited shot. Marfe was still below
the midplane. NINJA was mistakenly not enabled. Elongation was
reduced from 1.38 to 1.34.

Next shot: decrease elongation further by raising ZXL another 2 cm
and lowering ZXU by 2 cm, move plasma up by 1 cm, and increase
density to nl_04=1.3e20 m-2 (from 1.2), and enable the NINJA.
We are trying to get the marfe to be at the midplane.

Shot 11 -- Fizzle. Null looks good.

Next shot: reduce BR offset by 0.0005 (from 2.5 to 2.0 mT).

Shot 12 -- Plasma. Good 0.6 MA, 5.4 T limited shot. Marfe was still below
the midplane. Vertical position moved up 1 cm, but elongation
didn't change. Also, it turns out that the NINJA has not been
firing.

Next shot: repeat with no changes, except re-re-re-enable the NINJA.

Long delay (2 hours) due to a cell access, mostly for the TCI laser/alignment.

Shot 13 -- Plasma. Good 0.6 MA, 5.4 T limited shot. NINJA definitely puffed
this time, but marfe still stayed well below the midplane.

Next shot: ramp Btor down to 2.7 T, starting at t=0.5 s and ending
at t=0.9 s.

Shot 14 -- Plasma. Good 0.6 MA, limited shot. Bt ramped from 5.4 to 3.7 T,
and then the plasma disrupted. The TCI laser failed at 0.1 s.
The marfe was at the midplane on this shot.

Next shot: both shots on which the density feedback failed (shots
8 and 14) had the marfe at the midplane. Therefore I have copied
the valve trace from this shot and pasted it into the valve
programming. Density feedback gain has been turned almost all the
way off.

Shot 15 -- Plasma. 0.6 MA, limited. Bt ramped down, but shot disrupted at
0.85 s. It turns out that the impurity injector fired calcium
fluoride at that time. Also, the gas valve did not follow the
request, because I apparently did not load the reduced density
feedback.

Next shot: reduce density feedback to 0.1 (from 4).

Shot 16 -- Plasma. 0.6 MA, limited. Bt ramped down to 2.9 T, but midplane
marfe faded away early. No density information available.

Next shot: keep gas valve on at 50 volts until t=1.0 s.

Shot 17 -- Plasma. 0.6 MA, limited, Bt ramp. Disrupted at 1.09 s (when
Bt=3.2 T). Marfe lasted the entire shot. Thomson scattering give
a central density of 2.0e20 m-3.

Next shot: same, except start Bt ramp 100 ms earlier (at t=0.3 s.)

Delay due to cell access for RF.

Shot 18 -- Fizzle. BR is a little high.

Next shot: reduce Br offset another 1 mT (from 0.002 to 0.001 T)

Shot 19 -- Plasma. 0.6 MA, limited, Bt ramp, disrupted at 0.91 s.

Next shot: reload shot 6 from this morning (diverted, 0.8 MA, 5.4 T)
except copy in the gas voltage trace from shot 980122038 (which
had a nice midplane marfe) and turn down the density feedback (since
the TCI is still not working.)

Shot 20 -- Plasma. Good shot. 0.75 MA, 5.4 T, diverted.

Next shot: no changes. Bring scanning probe in.

Shot 21 -- Plasma. Good shot. Ethylene puffed in from scanning probe at
t=0.6 and 0.9 s.

Next shot: no changes.

Shot 22 -- Fizzle. Fields and gas look identical to shots that have gone.

Next shot: try again, no changes.

Shot 23 -- Fizzle. Perhaps Bz is a bit too high.

Next shot: reduce IC_EF4 by 15 amps.

Shot 24 -- Plasma. Good shot. 0.75 MA, 5.4 T, diverted, ethylene puffs from
F-port scanning probe. 1 MW of RF at end of pulse gives brief
H-mode.

Next shot: take another 10 amps off of EF4

Shot 25 -- Plasma. Good shot. 0.75 MA, 5.4 T, diverted, ethylene puffs from
F-port scanning probe. 1.3 MW of RF at end of pulse.

End of run.

Session Leader Comments
Apr 16 1999 08:14:42:013AMJim TerryThe purpose of the first half of the 990416 run is detatiled in MP 221A.
Briefly it is to vary the opacity of the D_0 Lyman lines by changing
the magnetic field strength, thereby changing the Zeeman splitting of
the lines, thereby possibly affecting the opacity.

The plan is to

1) Make a (diverted) plasma (load shot 990331029).

2) Make a reproducible, inner wall-limited plasma with a stable
midplane MARFE (we may need to induce the MARFE by a D_2 gas puff
from the midplane NINJA capillary (Load shot 980210035, starting with I_p at 800 kA,
but with no loop voltage modulation.)
If we get this discharge at 800 kA then we will drop the plasma current
to 600 kA.

3) ramp the toroidal field from 5.4 T down to 2.7 T, with the ramp starting
at ~ 0.6 s, ie ~200 ms after the MARFE developes. The B_t ramp rate should be
as fast as possible. q_95 will go from ~5.6 at 5.4 T to 2.8 at 2.7 T.

4) We will run this shot until we have a data set from all the spectroscopic
diagnostics (VUV, Chromex, U Md spectrometer, H/D ratio, reticons).

5) If time permits, we want to make a stable midplane MARFE in a DIVERTED
magnetic configuration. To do this we want to load segment 1
from shot 980122038 for the gas programming and
segment 2 from 990331029. (Start at 800 kA. If OK, then drop I_p to 600 kA.)

6) After obtaining a midplane MARFE, we will again ramp B_t down to 2.7 T.

For this run we will need D_2 available for the NINJA system (at 22 PSI) and
ECDC in D_2. GPC 1 will be set up to give temperature profiles
at 5.4 T, while GPC 2 will give profiles at the 2.6 T field.
Apr 16 1999 09:47:28:217AM990416006Jim TerryGood shot - diverted, now go to limited plasma
Apr 16 1999 10:14:01:373AM990416007Jim TerryGood shot - limited, MARFE somewhat below the midplane, starting at ~.15 s
Apr 16 1999 05:17:59:590PM990416008Jim TerryWent to 600 kA - I_p, lost TCI at 0.226 s, disrupted (slowly) at 0.628 s
No NINJA puff on that shot.
Apr 16 1999 10:51:49:093AM990416009Jim TerryGood shot, 600 kA - I_p, no NINJA puff, MARFE well below the midplane
Apr 16 1999 11:06:43:107AM990416010Jim TerryGood shot, 600 kA - I_p, no NINJA puff, MARFE still well below the midplane
Apr 16 1999 11:24:50:483AM990416011Jim Terryfizzle
Apr 16 1999 12:05:39:717PM990416012Jim Terry----------------------------------------------------------------------------
Good shot, 600 kA - I_p, MARFE still well below the midplane
still no NINJA
-
Apr 16 1999 01:46:54:950PM990416013Jim Terry----------------------------------------------------------------------------
Good shot, 600 kA - I_p, MARFE still well below the midplane
we saw the NINJA puff (start at .4, on for .5 at 470 T), but it
was small emission relative to the MARFE and did not raise the
position of the MARFE
Apr 16 1999 02:07:11:420PM990416014Jim Terry----------------------------------------------------------------------------
Good shot, 600 kA - I_p, slow disruption starting at 1.0s.
We ramped B_t from 5.4 to 2.7 T (ramp starting
at .5 s ending at .9 s). The MARFE is now on the midplane.
We saw the NINJA puff (start at .4, on for .5 at 470 T), but it
was still small emission relative to the MARFE.
Apr 16 1999 03:42:07:450PM990416014Jim TerryTV view of midplane D_alpha shows
the NINJA plume switch directions (toroidally)
depending on whether the MARFE is above or
below the capillary.
Apr 16 1999 02:19:32:217PM990416015Jim Terry----------------------------------------------------------------------------
OK shot, 600 kA - I_p, slow disruption starting at 0.86s,
probably caused by a CaF_2 injection.
We ramped B_t from 5.4 to 2.7 T (ramp starting
at .5 s ending at .9 s). The MARFE moves off of the midplane
after ~0.5 s. We saw the NINJA puff (start at .4, on for .5 at 470 T).
Apr 16 1999 02:43:02:827PM990416016Jim Terry----------------------------------------------------------------------------
Good shot, 600 kA - I_p
We ramped B_t from 5.4 to 2.7 T (ramp starting
at .5 s getting to 2.9 at 1.2 s). The MARFE is on the midplane
but disappears after ~0.5 s. No NINJA.
Apr 16 1999 03:27:11:997PM990416017Jim TerryGood shot, 600 kA - I_p, disrupted at 1.09 s.
B_t ramp. The MARFE moves off the midplane
to ~-0.12 m. No NINJA.
-
Apr 16 1999 03:25:14:857PM990416018Jim Terry----------------------------------------------------------------------------
fizzle
Apr 16 1999 04:08:22:450PM990416019Jim TerryBest shot for MARFE study. There was full coverage of the inner wall
by the Chromex. McP looking at Ly_beta thru Ly_8 in the relatively stable
MARFE at Z=-0.12 m. B_t ramped to 3.24 T before the plasma disrupted at
0.9 s.
Apr 16 1999 04:12:31:497PM990416020Jim TerryBack to good diverted 800 kA shot. Turned the run
over to Brian Labombard for burping probe
studies.

Physics Operator Comments
Apr 16 1999 08:05:07:467AMRobert GranetzEngineering Setup for Friday, 990416

Load from 990331029

Overnight ECDC in D2, stopping in time to begin run at 08:00.

---> *** TF under PLC control initially ***

Gas setup - fill B-top with 6 psi of D2 Hybrid enabled
fill B-side lower with 1 psi of Ar Hybrid DISABLED
fill B-side upper with 2 psi of Kr Hybrid DISABLED
fill C-side with 30 psi of D2 Hybrid enabled
leave J-bottom as is Hybrid DISABLED

fill NINJA with 22 psi of D2

(Later in the day we may want to refill the NINJA with ethylene.)

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

ECE, VUV
Apr 16 1999 08:50:30:793AMRobert GranetzRun Plan for 990416 (2 half-day miniproposals):

MP 221A -- Experimental study of Zeeman effect influence on opacity
MP 222 -- Impurity compression and enrichment studies

The purpose of the first half of the day (MP 221A) is to vary the
opacity of the D_0 Lyman lines by changing the magnetic field
strength, thereby changing the Zeeman splitting of the lines.
Inboard limited plasmas will be tried first in order to get bright marfes at
the midplane.

During the second half of the day (MP 222), the density will be varied, as will
the bypass position (open vs closed). The screening, compression, and
enrichment of impurities (Kr, Ar) will be measured.

Before the physics runs, we will need to do three test shots:

1) Usual 'Tuesday' OH test.
2) TF only test, 50 kA, 1 sec flattop (PLC control, disable fizzle detector)
3) TF only test, 150 kA, 1 sec flattop (PLC control, disable fizzle detector)

After these initial tests:
For 1st MP, start from plasma shot 990331023.
For 2nd MP, start from plasma shot 990305023 (note the power supply settings
for this long shot).
Apr 16 1999 08:10:09:670AM990416001Robert GranetzShot 01 -- OH test. All OK.

Next shot: TF-only test at 50 kA, for approximately 1 s flattop.
Apr 16 1999 08:23:57:420AM990416002Robert GranetzShot 02 -- TF-only test at 50 kA, for approximately 1 s flattop.

Next shot: TF-only test at 150 kA, for 1 s flattop (for magnetics
calibration.
Apr 16 1999 09:14:23:623AM990416004Robert GranetzShot 04 -- TF-only test at 150 kA, this time with 1 s flattop (for magnetics
calibration). Actually got 161 kA (5.7 T) for 1.4 s flattop.

Next shot: plasma; load from 990331023 (0.8 MA, diverted)
Apr 16 1999 09:31:40:967AM990416005Robert GranetzShot 05 -- Fizzle. BR had +2 mT offset.

Next shot: reduce BR offset by 2 mT (from 0.0045 to 0.0025 T), and
reduce pre-fill puff from 20 to 18 ms.
Apr 16 1999 09:51:28:623AM990416006Robert GranetzShot 06 -- Plasma. Good shot. Ip=0.75 MA, Bt=5.4 T, nl_04=0.9e20 m-2.

Next shot: 0.8 MA limiter plasma. Load from 980210035, but remove
the modulation on the plasma current.
Apr 16 1999 10:15:10:827AM990416007Robert GranetzCell access required for diagnostics purposes between shots 7 and 8.
Apr 16 1999 10:16:27:407AM990416007Robert GranetzShot 07 -- Plasma. Good limited shot at 0.77 MA, 5.4 T. Marfe on inboard
wall. nl_04=1.2e20 m-2.

Next shot: reduce Ip to 0.6 MA. Also, increase argon puff from 20
to 30 ms. Also NINJA D2 puffing at inboard midplane from t=0.50 for
duration of 0.15 s.
Apr 16 1999 10:35:54:640AM990416008Robert GranetzShot 08 -- Plasma. 0.6 MA. CO2 laser failed at 0.2 s, so we had no feedback
control of density. Discharge terminated slowly, ramping down over
0.2 s, to end at t=0.8 s. NINJA puffed D2 at inboard midplane.

Next shot: repeat, but with no NINJA puff. Lower NINJA plenum
pressure to 10 psi (from 22 psi).
Apr 16 1999 10:57:14:873AM990416009Robert GranetzShot 09 -- Plasma. Good 0.6 MA, 5.4 T limited shot. Marfe on inboard wall,
below the midplane. nl_04=1.2e20 m-2.

Next shot: decrease elongation by raising ZXL by 1.5 cm and
lowering ZXU by 1.3 cm. Turn on NINJA from t=0.4 to 0.9 s (with
plenum pressure reduced from 22 to 10 psi).
Apr 16 1999 11:15:18:997AM990416010Robert GranetzShot 10 -- Plasma. Good 0.6 MA, 5.4 T limited shot. Marfe was still below
the midplane. NINJA was mistakenly not enabled. Elongation was
reduced from 1.38 to 1.34.

Next shot: decrease elongation further by raising ZXL another 2 cm
and lowering ZXU by 2 cm, move plasma up by 1 cm, and increase
density to nl_04=1.3e20 m-2 (from 1.2), and enable the NINJA.
We are trying to get the marfe to be at the midplane.
Apr 16 1999 11:29:15:717AM990416011Robert GranetzShot 11 -- Fizzle. Null looks good.

Next shot: reduce BR offset by 0.0005 (from 2.5 to 2.0 mT).
Apr 16 1999 12:41:15:810PM990416012Robert GranetzShot 12 -- Plasma. Good 0.6 MA, 5.4 T limited shot. Marfe was still below
the midplane. Vertical position moved up 1 cm, but elongation
didn't change. Also, it turns out that the NINJA has not been
firing.

Next shot: repeat with no changes, except re-re-re-enable the NINJA.

Long delay due to a cell access.
Apr 16 1999 01:51:46:763PM990416013Robert GranetzShot 13 -- Plasma. Good 0.6 MA, 5.4 T limited shot. NINJA definitely puffed
this time, but marfe still stayed well below the midplane.

Next shot: ramp Btor down to 2.7 T, starting at t=0.5 s and ending
at t=0.9 s.
Apr 16 1999 02:12:23:577PM990416014Robert GranetzShot 14 -- Plasma. Good 0.6 MA, limited shot. Bt ramped from 5.4 to 3.7 T,
and then the plasma disrupted. The TCI laser failed at 0.1 s.
The marfe was at the midplane on this shot.

Next shot: both shots on which the density feedback failed (shots
8 and 14) had the marfe at the midplane. Therefore I have copied
the valve trace from this shot and pasted it into the valve
programming. Density feedback gain has been turned almost all the
way off.
Apr 16 1999 02:52:07:640PM990416015Robert GranetzShot 15 -- Plasma. 0.6 MA, limited. Bt ramped down, but shot disrupted at
0.85 s. It turns out that the impurity injector fired calcium
fluoride at that time. Also, the gas valve did not follow the
request, because I apparently not did load the reduced density feedback.

Next shot: reduce density feedback to 0.1 (from 4).
Apr 16 1999 02:40:56:060PM990416016Robert GranetzShot 16 -- Plasma. 0.6 MA, limited. Bt ramped down to 2.9 T, but midplane
marfe faded away early. No density information available.

Next shot: keep gas valve on at 50 volts until t=1.0 s.
Apr 16 1999 03:10:11:310PM990416017Robert GranetzShot 17 -- Plasma. 0.6 MA, limited, Bt ramp. Disrupted at 1.09 s (when
Bt=3.2 T). Marfe lasted the entire shot.

Next shot: same, except start Bt ramp 100 ms earlier (at t=0.3 s.)

Delay due to cell access for RF.
Apr 16 1999 03:22:25:653PM990416018Robert GranetzShot 18 -- Fizzle. BR is a little high.

Next shot: reduce Br offset another 1 mT (from 0.002 to 0.001 T)
Apr 16 1999 03:48:56:077PM990416019Robert GranetzShot 19 -- Plasma. 0.6 MA, limited, Bt ramp, disrupted at 0.91 s.

Next shot: reload shot 6 from this morning (diverted, 0.8 MA, 5.4 T)
except copy in the gas voltage trace from shot 980122038 (which
had a nice midplane marfe) and turn down the density feedback (since
the TCI is still not working.)
Apr 16 1999 03:58:13:780PM990416020Robert GranetzShot 20 -- Plasma. Good shot. 0.75 MA, 5.4 T, diverted.

Next shot: no changes. Bring scanning probe in.
Apr 16 1999 04:11:51:030PM990416021Robert GranetzShot 21 -- Plasma. Good shot. Ethylene puffed in from scanning probe at
t=0.6 and 0.9 s.

Next shot: no changes.
Apr 16 1999 04:29:36:013PM990416022Robert GranetzShot 22 -- Fizzle. Fields and gas look identical to shots that have gone.

Next shot: try again, no changes.
Apr 16 1999 04:42:37:280PM990416023Robert GranetzShot 23 -- Fizzle. Perhaps Bz is a bit too high.

Next shot: reduce IC_EF4 by 15 amps.
Apr 16 1999 05:01:22:763PM990416024Robert GranetzShot 24 -- Plasma. Good shot. 0.8 MA, 5.4 T, diverted, ethylene puffs from
F-port scanning probe. 1 MW of RF at end of pulse gives brief
H-mode.

Next shot: take another 10 amps off of EF4
Apr 16 1999 05:14:04:327PM990416025Robert GranetzShot 25 -- Plasma. Good shot. 0.75 MA, 5.4 T, diverted, ethylene puffs from
F-port scanning probe. 1.3 MW of RF at end of pulse.

End of run.

Engineering Operator Comments
ShotTimeTypeStatusComment
108:02:02:610AMTestOkOH test OK
208:21:29:263AMTestOk50KA TF test OK
308:49:29:247AMTestOkTF test shot only
409:03:27:530AMTestOkTF test only
509:18:50:060AMPlasmaOkno faults/Fizzel
609:40:21:890AMPlasmaOkno faults/plasma
709:57:15:997AMPlasmaOkno faults/plasma
810:20:03:733AMPlasmaOkno faults/plasma
910:42:51:247AMPlasmaOkno faults/plasma
1011:01:00:310AMPlasmaOkno faults/plasma
1111:20:47:090AMPlasmaOkno faults/fizzel
1211:37:36:890AMPlasmaOkno faults/plasma
1301:40:07:780PMPlasmaOkNo Faults
1401:54:45:623PMPlasmaOkNo Faults
1502:12:26:013PMPlasmaOkNo Faults
1602:30:15:700PMPlasmaOkNo Faults
1702:49:08:483PMPlasmaOkNo faults
1803:15:41:747PMPlasmaOk(null)
1903:29:01:500PMPlasmaOkNo faults
2003:47:49:920PMPlasmaOkNo Faults
2104:04:39:450PMPlasmaOkNo Faults
2204:21:27:297PMPlasmaOkNo Faults
2304:35:17:280PMPlasmaOkNo Faults
2404:49:05:043PMPlasmaOkNo Faults
2505:04:37:013PMTestBad