Alcator C-Mod Run 950316 Information

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Miniproposals
Miniproposal:091
Date Filed: 3/2/1995
Title:Non-recycling impurity screening study in diverted and limited
First Author:Ying Wang Wang
Session Leader:Ying Wang Wang (shots 1-37)

Operators
Session leader(s):Ying Wang Wang
Physics operator(s):Robert Granetz
Engineering operator(s):Vinny Bertolino

Engineering Operator Run Comment
impurity screening

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:12:710PM
Author: To Be Determined
Session Leader's summary of run 950316

MP# 091 Non-recycling impurity screening study in diverted and
limited plasmas

Physics Operator: Granetz
Session Leader: YWang
Engineering Operator: Bertolino

The goal of this run is to 1) compare non-recycling impurity screening
between single null diverted and limited plasmas. 2) study the scaling of
impurity screening as a function of electron density 3) study of effect of
impurity injection location on impurity screening. 4) verify the effect of
of helium discharge cleaning on argon screening.

---------------------------------------------------------------------------
Planned run sequence for MP91

Parameters:
B_T=5.3T
Ip=.8 MA
kappa = 1.50 - 1.50

Strike points fixed on vertical target plate between probe 2 and 3.

Shot parameters should be kept as constant as possible from shot to shot.
Suggest loading 950309009.

set line density at 1.2e20

shot 1 -- 2 No impurity injection. Long discharges to stabilize the
plasma density

shot 3,4,5 Try to keep conditions fixed. Sc injection only to
test the consistency of the laser ablation technique.

shot 6: Limited, Ar(B side lower) and Sc at .6 sec. Ar pulse 26ms
long at 4psi plenum pressure. (The pulse remain the same for the whole run)

shot 7: Limited, Ar(B side lower) and Sc at .6 sec. Fire FSP
at .50 s, .65 s,.90 s.

shot 8: Limited, Ar(divertor capillary) and Sc at .6 sec. Fire FSP
at .50 s, .65 s,.90 s.

shot 9: The same as shot 8.

shot 10-12: Diverted, No impurity injections. Adjusting the density.

shot 13: Diverted. no Ar. Sc injection at .6 s.

shot 14: Diverted. Ar(B side lower) and Sc at .6 sec. Fire FSP
at .50 s, .65 s,.90 s.

shot 15: Same as shot 14.

shot 16: Diverted. Ar(divertor capillary) and Sc at .6 sec. Fire
FSP at .50 s, .65 s,.90 s.

shot 17: Same as shot 16.

set line density at 7e19

repeat shot 6 - shot 16.

Set line density at 2.0e20

repeat shot 6 - shot 16.

15 minutes of He discharge cleaning.


set line density back to 1.2e20

shot 34, 35, 36: Ar(B side lower) and Sc at .6 sec. Fire FSP
at .50 s, .65 s,.90 s.
-------------------------------------------------------------------------

What really happened was:

The run was started with a diverted plasma loaded from shot 950315034 at
a line density of 1.2e20. Scandium was injected at shot 4, 5 and 8 and the
laser ablation technique proved to have good repeatability.
From shot 9 on, we switched to limited plasmas by limiting the plasma on the
inner wall. Contrary to expectations,shot 9 and shot 10 showed no deterioration
in impurity screening compared to the diverted shots. This prompted more
investigation and shot 11 - shot 21 were dedicated to this purpose. It turned
out that the SOL flux in shot 9 and 10 didn't circle around to terminate on
the inner wall. Instead, a large portion of the SOL flux was still terminated
on the outer divertor target plate, thus leaving shot 9 and shot 10 in a
"semi-diverted" state. It wasn't until shot 15 that we achieved a good limited
plasma. The impurity screening of the limited shots deteriorated a great deal
compared to the diverted shots and we had to reduce the plenum pressure for
B-side lower from 4 psi to 2 psi to keep the counting rate from going too high.
Shot 22 and 23 were the same as shot 21 except the argon was puffed through
NINJA divertor instead of B-side lower.
Shot 24 to 26 were back to diverted again with argon puffed from NINJA
divertor.
With only 10 more shots to do the density scan, we were forced to change the
original plan which asked for two identical shots for each setting and took one
shot for each setting. Also omitted was the NINJA puffing for the limited
shots.
The density for shots 27 to 31 was set to 7e19. Shot 27, 28 and 29 were
diverted. Shot 30 and 31 were limited.
The density was set to 2e20 for shot 32 and that probably made it a fizzle.
Shot 33 disrupted before .4 sec. The density then was reduced to 1.7e20 for the
rest of the run. One limited shot: 34. Two diverted shots: 35 and 36.

Sc was injected all through the run except for shot 01, fizzles and early
disruptions.

Preliminary result:
1. Divertor is still better than limiter in impurity screening.
2. Scandium screening is the same for divertor and limiter operation.
However, it has a strong dependance on electron temperature.


This run is successful in proving again the advantage of divertor in impurity
screening. Data are also successfully collected for the study of the effect of
impurity injection location on the impurity screening. However, it's less
successful in terms of collecting data for impurity screening scaling study
because the density scan was done in a hurry and the data quality was less than
satisfactory, especially for the high density shots. The study on the effect of
helium discharge cleaning was not carried out at all. It would be worthwhile
to redo the last one third of the MP# 091 in the future.

Physics Operator Summaries
Entered: Jul 7 2004 04:36:53:537PM
Author: To Be Determined
Physics operator's summary for run 950316

SL: Ying Wang
PO: R. Granetz
EO: V. Bertolino

This run is for MP 091, comparison of impurity screening between
limited and diverted plasmas using scandium laser ablation injection,
and also argon gas. Start with shot 950315034 from yesterday, adjust
the density to nl_04=1.2e20 m-2. (Density feedback gain is turned
on.). Set pre-fill at 2.3e-5 torr. This starting shot is diverted.
Later we will switch to a limited shot. This divertor/limiter comparison
will be done at medium, low, and high densities.

We accomplished some of the physics goals, especially at the medium and
lower densities. See the session leader's summary for preliminary results.

Most of the operational problems were with VDE disruptions, which were
usually due to railing the EF1 or EF2 current/voltage limits. Part of
this problem seemed to be mitigated by removing the slew-rate-limiting
boards. Only one shot failed because of a power supply problem.
Operation of stable limited plasmas lasting until rampdown was not
achieved today, but fortunately that didn't prevent us from obtaining
usable data. It turned out that we found it impossible to run highly
elongated limited plasmas (kappa > 1.5) and still have no SOL flow
into the divertor. We eventually had to settle for kappa=1.3 for the
limited plasmas.

Scorecard: 30 plasmas (some diverted, some limited, most disrupted)
5 fizzles
1 dud (EF1 problem)
1 TF test

Shot 001 - Plasma. Disrupted upward at 0.95 s due to VDE (pretty fast one,
with Ihalo_u=172 kA.
Next shot: enable argon puff and shit shooter.

Shot 002 - Fizzle. Not surprising given the previous upward disruption.
Next shot: repeat.

Shot 003 - Plasma. Disrupted downward at 0.36 s. Huge up/down oscillations
in vertical position, and the plasma current seemed stuck at
0.6 MA (around the time of cross-over).
Next shot: repeat.

Shot 004 - Plasma. Disrupted upward at 0.98 s (VDE). Another fast one with
high Ihalo_u=158 kA. Again, the slow ZCUR was lost due to EF1
voltage limitations. Argon and scandium injected at 0.6 s.
Next shot: repeat, but it'll probably fizzle.

Shot 005 - Plasma, Disrupted upward at 0.97 s (VDE). Engineers are checking
on a possible problem with EF1, which might explain these voltage
limitation problems. This shot had scandium and argon injection
at 0.6 s, and the scanning probe fired twice.
Next shot: move argon puff back from 0.6 to 0.5 s. Also move
scandium injection to 0.5 s as well.

A problem with the IGOR is holding up the next shot.

Shot 006 - Fizzle.
Next shot: repeat

Shot 007 - Fizzle.
Next shot: tweak EF4 more negative by 15 amps.

Shot 008 - Plasma. Disrupted upward at 1.01 s (VDE). Scandium and argon
injection at 0.5 s, and two scanning probe sweeps.
Next shot: change to limited configuration by moving CLEARIN in
by 2 cm, and the same for RCUR.
Keep argon and scandium injections enabled.

Shot 009 - Plasma. Disrupted down at 0.58 s. Plasma was toggling between
diverted and limited.
Next shot: decrease CLEARIN another 5 mm.

Engineers changed a slew-rate limiting board in EF1 prior to this shot.

Shot 010 - Plasma. No disruption. It was definitely limited. There was
very little difference in the amount of argon that got in, but
the initial transient was faster. Also not much difference in
scandium that got in either.
Next shot: repeat

There was a long pause before the next shot while the engineers hooked up
some instrumentation to EF1

Shot 011 - Plasma. No disruption. Very similar to the previous shot.
Not much difference in the impurity levels. Brian reports that
even though these shots are limited, the outboard SOL flow does
not go around the bottom of the plasma, but rather goes down into
the divertor. This is because the plasma is centered at Z=-2 cm,
in order for Brian's FSP to work. So for the next shot, we'll
move ZCUR up by 0.5 cm, which is still within the FSP's reach.
Next shot: move ZCUR up by 5 mm

Shot 012 - Plasma. Similar to previous shots. Brian still reports lots of
signal on the outer FMP array, even though plasma definitely moved
up by about 4 mm.
Next shot: Move ZXL lower by -2 cm.

Shot 013 - Plasma. Similar to 010, 011, 012. As with all of those shots,
argon and scandium were injected at 0.5 s. Brian still sees lots
of signal on the outer probes. The whole lower part of the plasma
seems to have been pulled down. Comparison of ZXL shows that it
did indeed move down 2 cm.
Next shot: return ZXL to its previous value, and move ZCUR up to
the midplane (from -1.5 cm).

Shot 014 - Plasma. It was centered, but much of the SOL still went into the
divertor. Argon at 0.5 s and scandium at 0.6 s.
Next shot: return ZCUR to -1.5 cm and make CLEARIN much more
negative (-0.02 --> -0.05 cm)

Shot 015 - Plasma. Disrupted down at 0.70 s (VDE). There was noticeable
marfe light on the inboard midplane this shot. It was definitely
really limited, but the elongation was only 1.3. The argon at 0.5 s
was much higher than previously, and may have indirectly led to
the disruption. Scandium injection was moved to 0.7 s, and thus
didn't make it before the disruption.
Next shot: reduce argon plenum pressure from 4 to 2 psi and repeat.

Shot 016 - Fizzle.
Next shot: repeat

Shot 017 - Fizzle. Null looks reasonable.
Next shot: reduce pre-fill from 2.3 to 2.1e-5 torr and repeat

Shot 018 - Plasma. Disrupted down at 0.67 s (VDE). Argon was less, due
to lower plenum pressure. No scandium injection on this shot.
Next shot: double slow ZCUR P gain starting at 0.5 s.

Shot 019 - Plasma. Disrupted down at 0.60 s. Shot didn't last long
enough for the scandium injection.
Next shot: return slow ZCUR P gain to 1.5, and increase CLEARIN
by 0.5 cm.

Shot 020 - Plasma. Disrupted at 0.85. Scandium got in on this shot.
Next shot: on a suggestion from Ian, make EF4 current 500 amps
more negative, hopefully leaving more current in the EF2's.

Shot 021 - Plasma. Disrupted at 0.95 s. Scandium and argon okay. Fast
scanning probe can't reach these plasmas (by 1.5 cm).
Next shot: puff argon from NINJA divertor, turn off argon puff
from B-side-lower. Also ramp a little more negative current in
EF4.

Shot 022 - Plasma. Disrupted at 0.72 s, but this was definitely a thermal
quench due to way too much argon from the NINJA system.
Next shot: reduce NINJA plenum pressure from 75 to 16 torr.

Shot 023 - Plasma. Disrupted at 0.91 s. No argon made it in.
Next shot: change back to diverted plasma by copying in CLEARIN
and ZCUR from shot 008. Also increase NINJA plenum pressure back
up to 80 torr. Note that the changes Ian suggested concerning EF4
are still incorporated.

Shot 024 - Plasma. Disrupted down at 0.40 s (VDE). Probably due to EF2's
hitting their current limit.
Next shot: repeat.

Shot 025 - Plasma. Disrupted down at 0.42 s (VDE). Again, the EF2's railed.
Next shot: copy in shot 008 and try again.

Shot 026 - Plasma. Disrupted up at 1.00 s (VDE). A lot of argon.
Next shot: Turn off NINJA, turn on argon from B-side-lower (with
plenum pressure reset to 4 psi). Lower density to nl04=0.7e20 m-2.
Also put in -500 ampere ramp in EF4 late in shot.

Shot 027 - Plasma. No disruption. Diverted, nl04=0.7e20 m-2. Good shot.
Argon and scandium injected. Several molybdenum injections also.
Next shot: turn on the fast scanning probe and repeat.

Shot 028 - Plasma. No disruption. Good shot. Argon and scandium injected.
Fast scanning probe worked okay.
Next shot: puff argon from NINJA rather than B-side-lower valve.

Shot 029 - Plasma. Another nice diverted shot. Argon puffed from NINJA
in the divertor, scandium injected at 0.7 s, and fast scanning
probe.
Next shot: go to limited plasma by moving CLEARIN to -4.5 cm, and
reducing RCUR by 2 cm. Keep ZCUR unchanged. (I actually copied
CLEARIN and RCUR from shot 022.)

Shot 030 - Plasma. Limited. Disrupted at 0.68 s (thermal quench). Lots of
argon. Scandium injection at 0.6 s.
Next shot: repeat

Shot 031 - Plasma. Limited. Disrupted down at 0.86 s (VDE). Lots of argon.
Scandium at 0.6 s. No scanning probe.
Next shot: raise density to nl04=2.0e20 m-2. Also put in a little
more negative ramp in EF4 current towards end of shot.

Shot 032 - Dud. EF1's failed to charge properly.
Next shot: repeat

Shot 033 - Plasma. Disrupted down at 0.39 s. It was a thermal quench,
probably due to too fast a density rise. This is still limited.
Next shot: reduce rate of density rise, and lower maximum density
from 2.0 to 1.7e20 m-2.

Shot 034 - Plasma. Limited. Disrupted at 0.72 s
Next shot: change to diverted plasma, and raise argon plenum
pressure to 4 psi. Correction: plenum pressure was left at 2 psi.

Shot 035 - Plasma. Diverted. Disrupted in rampdown at 1.07 s. Density made it
to 1.7e20 m-2. Argon and scandium injected again.
Next shot: increase argon plenum pressure from 2 to 4 psi, move
scandium injection to 0.9 s (to get the higher density), and
enable fast scanning probe.

Shot 036 - Plasma. Diverted. Disrupted up at 1.01 s (VDE). Scanning probe
worked okay. Argon injected okay. Scandium too.
This was the last plasma shot of the run.

Shot 037 - TF only magnet test. Turn off Fizzle detector.

End of run.

Session Leader Comments

Physics Operator Comments
Mar 16 1995 08:15:52:080AMRobert GranetzPhysics operator's summary for run 950316

SL: Ying Wang
PO: R. Granetz
EO: V. Bertolino

This run is for MP 091, comparison of impurity screening between limited and
diverted plasmas using scandium and/or titanium laser ablation injection, and
maybe also argon gas. Start with shot 950315034 from yesterday, adjust the
density to nl_04=1.2e20 m-2. (Density feedback gain is turned on.).
Set pre-fill at 2.3e-5 torr.

Mar 16 1995 08:42:45:490AM950316001Robert GranetzShot 001 - Plasma. Disrupted upward at 0.95 s due to VDE (pretty fast one,
with Ihalo_u=172 kA.
Next shot: enable argon puff and shit shooter.

Mar 16 1995 08:45:17:480AM950316002Robert GranetzShot 002 - Fizzle. Not surprising given the previous upward disruption.
Next shot: repeat.

Mar 16 1995 09:02:08:510AM950316003Robert GranetzShot 003 - Plasma. Disrupted downward at 0.36 s. Huge up/down oscillations
in vertical position, and the plasma current seemed stuck at
0.6 MA (around the time of cross-over).
Next shot: repeat.

Mar 16 1995 09:16:05:640AM950316004Robert GranetzShot 004 - Plasma. Disrupted upward at 0.98 s (VDE). Another fast one with
high Ihalo_u=158 kA. Again, the slow ZCUR was lost due to EF1
voltage limitations. Argon and scandium injected at 0.6 s.
Next shot: repeat, but it'll probably fizzle.

Mar 16 1995 09:27:19:320AM950316005Robert GranetzShot 005 - Plasma, Disrupted upward at 0.97 s (VDE). Engineers are checking
on a possible problem with EF1, which might explain these voltage
limitation problems. This shot had scandium and argon injection
at 0.6 s, and the scanning probe fired twice.
Next shot: move argon puff back from 0.6 to 0.5 s.

Mar 16 1995 09:51:27:610AM950316006Robert GranetzA problem with the IGOR is holding up the next shot.

Shot 006 - Fizzle.
Next shot: repeat

Mar 16 1995 10:07:07:440AM950316007Robert GranetzShot 007 - Fizzle.
Next shot: tweak EF4 more negative by 15 amps.

Mar 16 1995 10:15:40:940AM950316008Robert GranetzShot 008 - Plasma. Disrupted upward at 1.01 s (VDE). Scandium and argon
injection at 0.5 s, and two scanning probe sweeps.
Next shot: change to limited configuration by moving CLEARIN in.
Keep argon and scandium injections enabled.

Mar 16 1995 10:32:21:240AM950316009Robert GranetzShot 009 - Plasma. Disrupted down at 0.58 s. Plasma was toggling between
diverted and limited.
Next shot: decrease CLEARIN another 5 mm.

Mar 16 1995 10:47:04:890AM950316010Robert GranetzEngineers changed a slew-rate limiting board in EF1 prior to this shot.

Shot 010 - Plasma. No disruption. It was definitely limited. There was
very little difference in the amount of argon that got in, but
the initial transient was faster. Also not much difference in
scandium that got in either.
Next shot: repeat

Mar 16 1995 11:12:42:950AM950316011Robert GranetzThere was a long pause before the next shot while the engineers hooked up
some instrumentation to EF1

Shot 011 - Plasma. No disruption. Very similar to the previous shot.
Not much difference in the impurity levels. Brian reports that
even though these shots are limited, the outboard SOL flow does
not go around the bottom of the plasma, but rather goes down into
the divertor. This is because the plasma is centered at Z=-2 cm,
in order for Brian's FSP to work. So for the next shot, we'll
move ZCUR up by 0.5 cm, which is still within the FSP's reach.
Next shot: move ZCUR up by 5 mm

Mar 16 1995 11:29:29:280AM950316011Robert GranetzScandium and argon injected at 0.5 s. FSP scanned twice.

Mar 16 1995 11:26:09:030AM950316012Robert GranetzShot 012 - Plasma. Similar to previous shots. Brian still reports lots of
signal on the outer FMP array.
Next shot: Move ZXL lower by -2 cm.

Mar 16 1995 11:44:33:090AM950316013Robert GranetzShot 013 - Plasma. Similar to 010, 011, 012. As with all of those shots,
argon and scandium were injected at 0.5 s. Brian still sees lots
of signal on the outer probes. The whole lower part of the plasma
seems to have been pulled down. Comparison of ZXL shows that it
did indeed move down 2 cm.
Next shot: return ZXL to its previous value, and move ZCUR up to
the midplane (from -1.5 cm).

Mar 16 1995 12:10:03:190PM950316014Robert GranetzShot 014 - Plasma. It was centered, but much of the SOL still went into the
divertor. Argon at 0.5 s and scandium at 0.6 s.
Next shot: return ZCUR to -1.5 cm and make CLEARIN much more
negative (-0.02 --> -0.05 cm)

Mar 16 1995 12:24:28:200PM950316015Robert GranetzShot 015 - Plasma. Disrupted down at 0.70 s (VDE). There was noticeable
marfe light on the inboard midplane this shot. It was definitely
really limited, but the elongation was only 1.3. The argon at 0.5 s
was much higher than previously, and may have indirectly led to
the disruption. Scandium injection was moved to 0.7 s, and thus
didn't make it before the disruption.
Next shot: reduce argon plenum pressure from 4 to 2 psi and repeat.

Mar 16 1995 12:29:41:950PM950316016Robert GranetzShot 016 - Fizzle.
Next shot: repeat

Mar 16 1995 12:38:02:240PM950316017Robert GranetzShot 017 - Fizzle. Null looks reasonable.
Next shot: reduce pre-fill from 2.3 to 2.1e-5 torr and repeat

Mar 16 1995 12:57:33:010PM950316018Robert GranetzShot 018 - Plasma. Disrupted down at 0.67 s (VDE). Argon was less, due
to lower plenum pressure. No scandium injection on this shot.
Next shot: double slow ZCUR P gain starting at 0.5 s.

Mar 16 1995 01:11:01:270PM950316019Robert GranetzShot 019 - Plasma. Disrupted down at 0.60 s. Shot didn't last long
enough for the scandium injection.
Next shot: return slow ZCUR P gain to 1.5, and increase CLEARIN
by 0.5 cm.

Mar 16 1995 01:18:11:630PM950316020Robert GranetzShot 020 - Plasma. Disrupted at 0.85. Scandium got in on this shot.
Next shot: on a suggestion from Ian, make EF4 current 500 amps
more negative, hopefully leaving more current in the EF2's.

Mar 16 1995 01:39:22:950PM950316021Robert GranetzShot 021 - Plasma. Disrupted at 0.95 s. Scandium and argon okay. Fast
scanning probe can't reach these plasmas (by 1.5 cm).
Next shot: puff argon from NINJA divertor, turn off argon puff
from B-side-lower. Also ramp a little more negative current in
EF4.

Mar 16 1995 02:02:03:900PM950316022Robert GranetzShot 022 - Plasma. Disrupted at 0.72 s, but this was definitely a thermal
quench due to way too much argon from the NINJA system.
Next shot: reduce NINJA plenum pressure from 75 to 16 torr.

Mar 16 1995 02:13:32:620PM950316023Robert GranetzShot 023 - Plasma. Disrupted at 0.91 s. No argon made it in.
Next shot: change back to diverted plasma by copying in CLEARIN
and ZCUR from shot 008. Also increase NINJA plenum pressure back
up to 80 torr. Note that the changes Ian suggested concerning EF4
are still incorporated.

Mar 16 1995 02:21:59:570PM950316024Robert GranetzShot 024 - Plasma. Disrupted down at 0.40 s (VDE). Probably due to EF2's
hitting their current limit.
Next shot: repeat.

Mar 16 1995 02:27:57:490PM950316025Robert GranetzShot 025 - Plasma. Disrupted down at 0.42 s (VDE). Again, the EF2's railed.
Next shot: copy in shot 008 and try again.

Mar 16 1995 02:45:59:160PM950316026Robert GranetzShot 026 - Plasma. Disrupted up at 1.00 s (VDE). A lot of argon.
Next shot: Turn off NINJA, turn on argon from B-side-lower (with
plenum pressure reset to 4 psi). Lower density to nl04=0.7e20 m-2.
Also put in -500 ampere ramp in EF4 late in shot.

Mar 16 1995 02:57:48:510PM950316027Robert GranetzShot 027 - Plasma. No disruption. Diverted, nl04=0.7e20 m-2. Good shot.
Argon and scandium injected. Several molybdenum injections also.
Next shot: turn on the fast scanning probe and repeat.

Mar 16 1995 03:13:36:050PM950316028Robert GranetzShot 028 - Plasma. No disruption. Good shot. Argon and scandium injected.
Next shot: puff argon from NINJA rather than B-side-lower valve.

Mar 16 1995 03:23:45:700PM950316028Robert GranetzFast scanning probe worked okay.

Mar 16 1995 03:27:27:860PM950316029Robert GranetzShot 029 - Plasma. Another nice diverted shot. Argon puffed from NINJA
in the divertor, scandium injected at 0.7 s, and fast scanning
probe.
Next shot: go to limited plasma by moving CLEARIN to -4.5 cm, and
reducing RCUR by 2 cm. Keep ZCUR unchanged.

Mar 16 1995 03:43:29:250PM950316030Robert GranetzShot 030 - Plasma. Limited. Disrupted at 0.68 s (thermal quench). Lots of
argon. Scandium injection at 0.6 s.
Next shot: repeat

Mar 16 1995 03:55:50:300PM950316031Robert GranetzShot 031 - Plasma. Limited. Disrupted down at 0.86 s (VDE). Lots of argon.
Scandium at 0.6 s. No scanning probe.
Next shot: raise density to nl04=2.0e20 m-2. Also put in a little
more negative ramp in EF4 current towards end of shot.

Mar 16 1995 04:02:00:690PM950316032Robert GranetzShot 032 - Dud. EF1's failed to charge properly.
Next shot: repeat

Mar 16 1995 04:16:24:380PM950316033Robert GranetzShot 033 - Plasma. Disrupted down at 0.39 s. It was a thermal quench,
probably due to too fast a density rise. This is still limited.
Next shot: reduce rate of density rise, and lower maximum density
from 2.0 to 1.7e20 m-2.

Mar 16 1995 04:24:53:120PM950316034Robert GranetzShot 034 - Plasma. Limited. Disrupted at 0.72 s
Next shot: change to diverted plasma, and raise argon plenum
pressure to 4 psi.

Mar 16 1995 04:30:37:520PM950316034Robert GranetzCorrection: plenum pressure was left at 2 psi.

Mar 16 1995 04:36:37:560PM950316035Robert GranetzShot 035 - Plasma. Disrupted in rampdown at 1.07 s. Density made it
to 1.7e20 m-2. Argon and scandium injected again.
Next shot: increase argon plenum pressure from 2 to 4 psi, move
scandium injection to 0.9 s (to get the higher density), and
enable fast scanning probe.

Mar 16 1995 04:49:26:880PM950316036Robert GranetzShot 036 - Plasma. Diverted. Disrupted up at 1.01 s (VDE). Scanning probe
worked okay. Argon injected okay. Scandium too.
This was the last plasma shot of the run.

Mar 16 1995 04:54:48:420PM950316037Robert GranetzShot 037 - TF only magnet test. Turn off Fizzle detector.

End of run.

Engineering Operator Comments
ShotTimeTypeStatusComment
108:28:34:470AMPlasmaOkno faults
208:41:36:930AMPlasmaOkno faults
308:49:59:530AMPlasmaOkno faults
409:07:07:770AMPlasmaOkno faults
509:20:40:980AMPlasmaOkno faults
609:47:41:530AMPlasmaOkno faults
709:57:53:250AMPlasmaOkno faults
810:08:58:210AMPlasmaOkno faults
910:23:25:340AMPlasmaOkno faults
1010:36:39:090AMPlasmaOkno faults
1111:03:57:290AMPlasmaOkno faults
1211:17:23:280AMPlasmaOkno faults
1311:30:34:520AMPlasmaOkno faults
1411:49:39:950AMPlasmaOkno faults
1512:11:15:050PMPlasmaOkno faults
1612:24:05:860PMPlasmaOkno faults
1712:33:05:300PMPlasmaOkno faults
1812:45:47:850PMPlasmaOkno faults
1912:59:10:540PMPlasmaOkno faults
2001:11:41:490PMPlasmaOkno faults
2101:25:50:470PMPlasmaOkComm fault EF1 U&L, OH1
2201:39:03:550PMPlasmaOkno faults
2302:03:25:510PMPlasmaOkno faults
2402:15:00:370PMPlasmaOkno faults
2502:24:30:840PMPlasmaOkno faults
2602:34:21:180PMPlasmaOkno faults
2702:47:07:740PMPlasmaOkno faults
2803:04:37:240PMPlasmaOkno faults
2903:19:41:220PMPlasmaOkNo Faults.
3003:32:46:710PMPlasmaOknofaults
3103:45:15:640PMPlasmaOkno faults
3203:58:01:590PMPlasmaBadef1's don't follow commands
3304:07:43:280PMPlasmaOkno faults
3404:18:02:540PMPlasmaOkno faults
3504:29:18:560PMPlasmaOkno faults
3604:40:24:430PMPlasmaOkno faults
3704:51:38:350PMTestOkTF only