Alcator C-Mod Run 1000830 Information

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Miniproposals
Miniproposal:268
Date Filed: 4/7/2000
Title:Conditioning of D-, E-, or J-Port ICRF Antenna
First Author:Gerd Schilling
Session Leader:Gerd Schilling (shots 1-25)
Session Leader:John Goetz (shots 1-25)

Operators
Session leader(s):Gerd Schilling,John Goetz
Physics operator(s):Steve Wolfe
Engineering operator(s):Bill Byford,Bill Parkin,Bill Cochran

Engineering Operator Run Comment
Wolfe,Parkin.

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:24:697PM
Author: To Be Determined
Run 1000830 -- MP #268 - ICRF Conditioning

EO: Cochran, Byford, Parkin
PO: Wolfe
SL: Goetz, Bonoli, Schilling, Wukitch (in absentia)

The objective of this MiniProposal is to condition the D-, E-, and J-port
antennas and make them ready for plasma physics operation. A secondary
objective is to document the performance of the J-Port antenna after the
changes/improvements of the recent up-to-air period.

The run started with conditioning shots. Each antenna was fired separately
into an inner-wall limited, 1MA, 5.2T plasma with nl04 ~ 1. This was to ensure
L-mode conditions so that inter-antenna comparisons are straightforward. The
D- and E-port antennas conditioned up easily with 1.35MW being launched from
each antenna after a few shots. The E-port antenna performed well throughout
this L-mode period. However, D-port began to fault at the higher powers and it
was necessary to reduce the power to clean up the faulting conditions before
once again increasing the power.

On the other hand, the J-port antenna did not condition very well. The first
two shots at 0.5 and 0.8MW (0.25 and 0.4 per transmitter) ran well. After
that, the antenna began to fault and produce copious amounts of ejecta. The
injections into the plasma were claimed to be not molybdenum. The
most likely location for trouble was the lower corner near H-port. It
appears from the camera view that there is a glow in this area whenever the
antenna is on and if the power level gets too high, this glow results in an
eruption. The first twelve shots determined that 0.8MW is the upper limit
for total power launched from the J-port antenna before injections occur.

The next four shots (13-16) were an outer gap scan (1.5, 2.0, 1.0, 0.5cm)
with low power ramps from each antenna. This was to determine if the parallel
resistance behavior was different from that before the antenna box was 'closed'
during the up-to-air. At first glance, it appears that the parallel
resistance is similar to that achieved before 'closing the box', i.e., the
J-port antenna parallel resistance vs. power behaves differently than D and E
at low power.

The next four shots (17-20) were an outer gap scan (0.5, 1.0, 1.5, 2.0cm)
with equal power from each antenna to gather a measure of antenna performance.
This power was 0.8MW as this is the previously determined limit for the J-port
antenna. These shots, particularly 19 and 20, show that the performance of
the J-port antenna, when operated as a 4-strap, does not equal that of the
D- and E-port antennas. The central temperature increase, stored energy
increase, and the neutron rate are much lower (>= 40%) for the J-port antenna
compared to the other two antennas. An interesting note is that the D- and
E-port antenna performance is equivalent only if the E-port antenna is fired
first during the discharge. It was not determined why this is happening.

Some other observations from this scan were that D and E heated best with an
outer gap of ~1.5cm, and that J-port performance was best for gaps > 1.5cm,
i.e., the waveform was cleaner and fewer injections were seen.

Shot 21 was used to determine if the relative phase of the 4 current straps
of the J-port antenna was responsible for the observed behavior. This shot
had [0,1,1,0]*!pi phasing versus the [0,1,0,1]*!pi (or nearly) phasing of
the previous twenty shots. Shot 21 had continuous multiple injections from
everywhere along the J-port antenna, so the phasing was returned to
[0,1,0,1]*!pi.

The next four shots (22-25) were diverted plasmas with the antenna waveforms
overlapped to have enough power to get H-mode tunes for the run on 1000831.
This was successful in that some not very steady-state EDA H-modes were
produced that allowed for 1MA H-mode tuning points to be obtained.
D-port ran well through these shots but E-port needed some extra tuning to get
past a screen overload condition in the transmitter. It is interesting to
note that the same 0.8MW total power limit for J-port was still in effect
and that the tune for the J-port antenna was not different for H- and L-modes.

Overall summary:
D- and E-port antennas are conditioned and ready for plasma physics operations.
The J-port antenna performance is still degraded compared to the other
antennas even after the fixes during the up-to-air. In addition, the antenna
is limited to <0.8MW total power before it has detrimental effects on the
plasma.

Shot Result
---- ------
001 EF4 test shot

002 0.25MW from D-port; no faults
0.25MW from E-port; no faults
0.24MW from J3; no faults
0.25MW from J4; no faults

003 0.5MW from D-port; no faults
0.5MW from E-port; no faults
0.37MW from J3; no faults
0.41MW from J4; no faults

004 0.76MW from D-port; no fauts
0.74MW from E-port; no faults
0.62MW from J3 then max faults
0.69MW from J4 then max faults

005 1.1MW from D-port; no faults
1.1MW from E-port; no faults
0.60MW from J3 and 0.62MW from J4; disruption caused by injection
from lower H-port side of J-antenna

006 1.29MW from D-port; one fault on ramp-up
1.26MW from E-port; no faults
0.58MW from J3 and 0.65MW from J4; both had a fault in the middle
and both turned off early

007 1.34MW from D-port; one fault
1.31MW from E-port; no faults
0.49MW from J3 and 0.53MW from J4; both faulted just before turn-off
due to a large injection from the lower H-port side of the
antenna; Boswell is of the opinion that there is a plasma
forming behind the Faraday screen

008 1.30MW from D-port; four faults
1.25MW from E-port; no faults
0.38MW from J3; no faults
0.42MW from J4; no faults

009 1.0MW from D-port; no faults
1.0MW from E-port; no faults
0.37MW from J3; no faults
0.45MW from J4; no faults

010 1.15MW from D-port; no faults
1.10MW from E-port; no faults
0.42MW from J3; no faults
0.47MW from J4; no faults

011 1.25MW from D-port; no faults
1.18MW from E-port; no faults
0.42MW from J3; no faults
0.47MW from J4; no faults; both are in trouble near the end; some
injections seen on the camera beginning soon after max power

012 1.29MW from D-port; no faults
1.30MW from E-port; no faults
0.44MW from J3; no faults
0.47MW from J4; no faults but injections kill this one early

013 0.25MW from D-port; no faults; good ramp
0.25MW from E-port; no faults; good ramp
0.21MW from J3; no faults; good ramp
0.24MW from J4; no faults; good ramp
**this was done at an outer gap of ~1.5cm**

014 0.25MW from D-port; no faults; good ramp
0.25MW from E-port; no faults; good ramp
0.21MW from J3; no faults; good ramp
0.24MW from J4; no faults; good ramp
**this was done at an outer gap of ~2.1cm**

015 0.25MW from D-port; no faults; good ramp
0.25MW from E-port; no faults; good ramp
0.21MW from J3; no faults; good ramp
0.24MW from J4; no faults; good ramp
**this was done at an outer gap of ~1.1cm**

016 0.25MW from D-port; no faults; good ramp
0.25MW from E-port; no faults; good ramp
0.21MW from J3; no faults; good ramp
0.24MW from J4; no faults; good ramp
**this was done at an outer gap of ~0.5cm**

017 0.79MW from D-port; no faults
0.78MW from E-port; no faults
0.38MW from J3; two faults
0.42MW from J4; two faults; lots of injections from J-port
upper and lower H-port corners ejecting stuff
even something seen coming from the middle of the antenna
**this was done at an outer gap of ~0.4cm**

018 0.79MW from D-port; no faults
0.79MW from E-port; no faults
0.37MW from J3; no faults
0.41MW from J4; five faults at the end
one big and lots of little injections from J-port
**this was done at an outer gap of ~1.1cm**

019 0.78MW from D-port; no faults
0.79MW from E-port; no faults
0.37MW from J3; no faults
0.41MW from J4; no faults; no injections from J-port
J-port performance worse than D and E (0.5keV temp. increase
versus 0.9keV for D,E)
**this was done at an outer gap of ~1.5cm**

020 0.72MW from D-port; no faults
0.75MW from E-port; no faults
0.37MW from J3; no faults
0.42MW from J4; no faults; no injections from J-port
**this was done at an outer gap of ~2.1cm**

021 0.77MW from D-port; no faults
0.79MW from E-port; no faults
0.37MW from J3; no faults
0.42MW from J4; no faults
continuous multiple injections from everywhere along J-port
no heating or neutron rate change with J-port with [0,1,1,0]*!pi
**this was done at an outer gap of ~1.4cm**

022 diverted discharge, multiple H-modes
1.0MW from D-port; no faults
0.94MW from E-port; one DC0 fault and a screen crowbar
0.37MW from J3; one fault
0.42MW from J4; one fault

023 diverted discharge, multiple H-modes
0.93MW from D-port; no faults
0.45MW from E-port; one DC0 fault and a screen crowbar
0.37MW from J3; no faults
0.42MW from J4; no faults; J antenna looks pretty quiet on this one

024 diverted discharge, multiple H-modes; early disruption (injections)
0.97MW from D-port; no faults
0.73MW from E-port; no faults
0.43-.47MW from J3; three faults
0.44-.53MW from J4; three faults
J antenna looks nasty on this one (at least on the TV)

025 diverted discharge, multiple H-modes
1.0-1.15MW from D-port; one fault
0.75-.82MW from E-port; no faults
0.42MW from J3; three faults
0.43MW from J4; two faults
lower H-port side of J antenna looks nasty (appears to be
behind the screen)

Physics Operator Summaries
Entered: Jul 7 2004 04:37:11:850PM
Author: To Be Determined
Physop Summary for Wed, August 30, 2000

MP 268: ICRF Conditioning
SL: Goetz/Schilling
PO: wolfe
EO: The Bills (Cochran, Byford, Parkin)
------------------------------------------------------------

Engineering Setup:

ECDC overnight in Deuterium, stopping 1-2 hours before run.

Run begins at 9:00 and ends at 17:00.

Power system setup: Same as for 1000824002
Set OH1, OH2U and OH2L fizzle delays at 300ms
Set TF fizzle delay at 400 ms


Gas setup: B-Top 6 psi D2 Hybrid Enabled
B-side lower 1 psi Argon Hybrid DISABLED
B-side Upper As is HYBRID DISABLED
C-side 30 psi D2 Hybrid Enabled
J-bottom As is Hybrid DISABLED

The following Gate Valves should be ENABLED, assuming vacuum ok:
ECE, VUV

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

If the RF guys aren't here for first shot, we'll start with the 2sec, 3kA,
EF4-only shot; the attempt on 1000829032 didn't give a clean result, due to
induced current in EF3. Therefore, this test will be done with hybrid control,
using the reverse (positive) bridge. The EF4 coils must be fully cold for
this test. The fizzle detector should be moved to the end of the EF4 pulse
(1.0 sec) and all other supplies turned off; EF4 should be set up with the
usual limits. A 2 sec square pulse at 3kA (each coil) will be programmed in
PCS . If RF is ready for plasma, I'll sneak this test in later in the day.

The plasma run will start with a 1MA, 9e19, 5.2T limiter discharge similar to
1000824002, but with CLEARIN offset set at 12700 and CLEARIN waveform drawn to
-.015, to get it back to "real", nearly current-independent settings.

Most shots will be inner wall limited to avoid H-mode transitions. The program
will consist of
1.) power testing and conditioning for D, E, and J-port
2.) low-power ramps for D, E, and J
3.) power steps to do heating comparisons
4.) gap, density, I, and Bt scans

Results:
-------

The EF4 shot for analysis of the BP coil response was completed successfully
on shot #1.

Plasmas ran successfully at 1MA, 5.2T, limited with the modified CLEARIN
program, as previously implemented in May/June.

D&E operated well all day. At powers above 1MW or so, J caused disruptive
injections, apparently originating from a single region of the Faraday screen
(lower part to the H-port side).

A gap scan with all three antennas ramping at low power was carried out on
shots 13-16, and at higher power with flat RF on shots 17-20. The phase on
J-port was changed from 0-pi-0-pi to 0-pi-pi-0 on shot 21. Unfortunately, the
results seem to indicate (to a non-specialist) that the J-port performance has
not been improved by the mods made during the vent. See the Session Leader's
summary (and APS poster) for details.

One point is that the J-port pulse raises the midplane pressure by about
.15mTorr at the .8MW level, and this did not seem to get better throughout the
day. This seems to indicate that there may be something to be gained by
further conditioning of this antenna.

For shot 22 we began running diverted plasmas, with the RF stacked, to try to
develop tune for H-mode experiments. EDA H-modes were obtained. Shot 23 ran
full length. Shot 24 had a .3sec long, fairly steady, EDA H-mode, with
W~120kJ. Shot 25 had a similar length H-mode, and survived to full length.

In the physop (wirehead) department, I noticed that the RCUR and outer gap
were changing in rampdown (plasma moving in), although a constant waveform was
programmed in both RCUR and CLEARIN. This behavior would be consistent with an
error in the offset on RCUR. I adjusted the RCUR offset in Segment 2 from
+8000 to 0., and this seemed to help in the sense of keeping the RCUR more
nearly constant in rampdown. However, it isn't clear that this passes the
sanity check, because the RCUR that needs to be drawn had to be further in by
8mm (at 1MA), and this is the wrong direction relative to where we think the
plasma actually is. The acid test will be to use this value at different
currents, and verify whether it has better current immunity than the previous
value. Then a braver physop than I can change the value in Segment 1,
presently at 5500; there is some legitimacy to putting an incorrect value in
at startup, since we benefit from forcing Bz in by feedback before we can
really measure the position, so we may want to just leave the segment 1 offset
alone and adjust the waveform to match at .1sec.

I did some more fiddling in rampdown, although all the plasmas that didn't
get killed by RF-induced injections ramped all the way down. Some of the
techniques may help on days when the plasmas aren't so nice, though. One point
is that ramping IC_EF4 down hard at EOF, while keeping EF2byEF4 constant at
-2000, helps keep the EF2's from going to zero in rampdown.

The machine ran extremely well today. We had 24 plasmas out of 24 attempts,
with no changes to the startup at all. Six shots disrupted due to RF-induced
injections, the rest all ran over 1.9sec.

H/D started the day around 3%, but had gone up to 7% (or higher) by the end of
the run.

One of the disruptions zapped the RGA. Tommy fixed it (or switched to another)
after the run.



Session Leader Comments
Aug 30 2000 09:15:02:933AM1000830001John GoetzShot 1000830001
EF4 test shot
Aug 30 2000 09:30:42:653AM1000830002John GoetzShot 1000830002:
0.25MW from D-port @ 0.7s
0.25MW from E-port @ 0.95s
0.5 MW from J-port @ 1.2s

Results:
0.25MW from D-port; no faults
0.25MW from E-port; no faults; very noisy signal
0.24 from J3; no faults
0.25 from J4; no faults
voltage JV_4 is low compared to its friends
phasing is [0,1,-0.1,0.9]*!pi
Aug 30 2000 09:42:02:420AM1000830003John GoetzShot 1000830003:
0.5MW from D-port @ 0.7s
0.5MW from E-port @ 0.95s
0.8 MW from J-port @ 1.2s

Results:
0.5MW from D-port; no faults
0.5MW from E-port; no faults; very noisy signal
the transmitter looks quiet though
0.37 from J3; no faults
0.41 from J4; no faults
voltage JV_4 is low, JV_3 is high compared
Aug 30 2000 09:53:34:983AM1000830004John GoetzShot 1000830004:
0.75MW from D-port @ 0.7s
0.75MW from E-port @ 0.95s
1.5 MW from J-port @ 1.2s

Results:
0.76MW from D-port; no faults
0.74MW from E-port; no faults; Prefl is noisy
0.62MW from J3 then max faults
0.69MW from J4 then max faults

Aug 30 2000 10:10:30:780AM1000830005John GoetzShot 1000830005:
1.0MW from D-port @ 0.7s
1.0MW from E-port @ 0.95s
1.2 MW from J-port @ 1.2s

Results:
1.1MW from D-port; no faults
1.1MW from E-port; no faults; Prefl is noisy
D-port appears to be heating better than E-port; just over 2kV during D-port pulse
0.60MW from J3
0.62MW from J4
disruption caused by injection from lower H-port side of J-antenna; difficult
to say if it from the tiles or the screen

Aug 30 2000 10:29:07:500AM1000830006John GoetzShot 1000830006:
1.25MW from D-port @ 0.7s
1.25MW from E-port @ 0.95s
1.2 MW from J-port @ 1.2s

Results:
1.29MW from D-port; one fault on ramp-up
1.26MW from E-port; no faults
D-port appears to be heating better than E-port; just over 2.3kV during D-port pulse and more neutrons
0.58MW from J3
0.65MW from J4
both had a fault in the middle and both turned off early; no injection this time caught on camera
but the 2pi indicates some junk coming in when they shut off early
Aug 30 2000 10:56:57:547AM1000830007John GoetzShot 1000830007:
1.4MW from D-port @ 0.7s
1.4MW from E-port @ 0.95s
1.0MW from J-port @ 1.2s

Results:
1.34MW from D-port; one fault
1.31MW from E-port; no faults
D-port appears to be heating better than E-port; just under 2.5kV during D-port pulse and more neutrons
0.49MW from J3
0.53MW from J4
both faulted just before turn-off due to a large injection from the lower H-port side of the antenna;
Boswell is of the opinion that there is a plasma forming behind the Faraday screen (as deduced from the
camera view)
Aug 30 2000 11:12:09:827AM1000830008John GoetzShot 1000830008:
1.25MW from E-port @ 0.7s
1.25MW from D-port @ 0.95s
0.8MW from J-port @ 1.2s

Results:
1.30MW from D-port; four faults
1.25MW from E-port; no faults
can't make a heating comparison because of the D-port faults
0.38MW from J3; no faults
0.42MW from J4; no faults
the glow from the lower H-port corner is there almost throughout the pulse, but no
real injection problems
Aug 30 2000 11:28:55:437AM1000830009John GoetzShot 1000830009:
1.0MW from E-port @ 0.7s
1.0MW from D-port @ 0.95s
0.8MW from J-port @ 1.2s

Results:
1.0MW from D-port; no faults
1.0MW from E-port; no faults
D and E end up at about the same temperature but the neutron rate with D is a tick higher
0.37MW from J3; no faults
0.45MW from J4; no faults
the glow from the lower H-port corner is there almost throughout the pulse, but no
real injection problems
Aug 30 2000 11:48:45:000AM1000830010John GoetzShot 1000830010:
1.1MW from E-port @ 0.7s
1.1MW from D-port @ 0.95s
0.9MW from J-port @ 1.2s; change digital phase from 210 to 220

Results:
1.15MW from D-port; no faults
1.10MW from E-port; no faults
D and E end up at about the same temperature and neutron rate
0.42MW from J3; no faults
0.47MW from J4; no faults
the glow from the lower H-port corner is there almost throughout the pulse, but no
real injection problems
it has also been noted that there is a torus pressure rise (>50%) when J-port antenna is on
Aug 30 2000 12:10:44:827PM1000830011John GoetzShot 1000830011:
1.2MW from E-port @ 0.7s
1.2MW from D-port @ 0.95s
0.9MW from J-port @ 1.2s; change digital phase from 220 to 195

Results:
1.25MW from D-port; no faults
1.18MW from E-port; no faults
D maybe a little better than E
0.42MW from J3; no faults
0.47MW from J4; no faults
both are in trouble near the end;
some injections seen on the camera beginning soon after the antenna reaches max power
phase is [0,1,0,1]*!pi
Aug 30 2000 12:29:55:230PM1000830012John GoetzShot 1000830012:
1.3MW from E-port @ 0.7s
1.25MW from D-port @ 0.95s
0.9MW from J-port @ 1.2s; change digital phase from 220 to 195

Results:
1.29MW from D-port; no faults
1.30MW from E-port; no faults
D and E similar; good comparison shot
0.44MW from J3; no faults
0.47MW from J4; no faults
injections kill this one early
injections seen on the camera beginning soon after the antenna reaches max power

Aug 30 2000 12:48:19:170PM1000830013John GoetzShot 1000830013:
ramp from 0 to 0.25MW from D-port @ 0.6s
ramp from 0 to 0.25MW from E-port @ 0.9s
ramp from 0 to 0.25 on each of J-port @ 1.2s

Results:
0.25MW from D-port; no faults; good ramp
0.25MW from E-port; no faults; good ramp
0.21MW from J3; no faults; good ramp
0.24MW from J4; no faults; good ramp

**this was done at an outer gap of ~1.5cm**
Aug 30 2000 01:12:49:560PM1000830014John GoetzShot 1000830014:
change outer gap to 2.0cm
ramp from 0 to 0.25MW from D-port @ 0.6s
ramp from 0 to 0.25MW from E-port @ 0.9s
ramp from 0 to 0.25 on each of J-port @ 1.2s

Results:
0.25MW from D-port; no faults; good ramp
0.25MW from E-port; no faults; good ramp
0.21MW from J3; no faults; good ramp
0.24MW from J4; no faults; good ramp

**this was done at an outer gap of ~2.1cm**
Aug 30 2000 01:32:16:310PM1000830015John GoetzShot 1000830015:
change outer gap to 1.0cm
ramp from 0 to 0.25MW from D-port @ 0.6s
ramp from 0 to 0.25MW from E-port @ 0.9s
ramp from 0 to 0.25 on each of J-port @ 1.2s

Results:
0.25MW from D-port; no faults; good ramp
0.25MW from E-port; no faults; good ramp
0.21MW from J3; no faults; good ramp
0.24MW from J4; no faults; good ramp

**this was done at an outer gap of ~1.1cm**
Aug 30 2000 01:54:57:780PM1000830016John GoetzShot 1000830016:
change outer gap to 0.5cm
ramp from 0 to 0.25MW from D-port @ 0.6s
ramp from 0 to 0.25MW from E-port @ 0.9s
ramp from 0 to 0.25 on each of J-port @ 1.2s

Results:
0.25MW from D-port; no faults; good ramp
0.25MW from E-port; no faults; good ramp
0.21MW from J3; no faults; good ramp
0.24MW from J4; no faults; good ramp

**this was done at an outer gap of ~0.5cm**
Aug 30 2000 02:24:58:547PM1000830017John GoetzShot 1000830017:
0.8MW from D-port @ 0.6s
0.8MW from E-port @ 0.9s
0.4MW on each of J-port @ 1.2s

Results:
0.79MW from D-port; no faults
0.78MW from E-port; no faults
Once again, D-port is better than E-port when it is operated first
0.38MW from J3; two faults
0.42MW from J4; two faults
lots of injections from J-port
upper and lower H-port corners ejecting stuff
even something seen coming from the middle of the antenna

**this was done at an outer gap of ~0.4cm**
Aug 30 2000 02:39:50:060PM1000830018John GoetzShot 1000830018:
change outer gap to 1.0cm
0.8MW from D-port @ 0.6s
0.8MW from E-port @ 0.9s
0.4MW on each of J-port @ 1.2s

Results:
0.79MW from D-port; no faults
0.79MW from E-port; no faults
D and E-port performance about equal
0.37MW from J3; no faults
0.41MW from J4; five faults at the end
one big and lots of little injections from J-port
upper and lower H-port corners ejecting stuff
J-port performance worse than D and E

**this was done at an outer gap of ~1.1cm**
Aug 30 2000 02:59:24:200PM1000830019John GoetzShot 1000830019:
change outer gap to 1.5cm
0.8MW from D-port @ 0.6s
0.8MW from E-port @ 0.9s
0.4MW on each of J-port @ 1.2s

Results:
0.78MW from D-port; no faults
0.79MW from E-port; no faults
D and E-port performance about equal
0.37MW from J3; no faults
0.41MW from J4; no faults
no injections from J-port
J-port performance worse than D and E (0.5keV temp. increase versus 0.9keV for D,E)

**this was done at an outer gap of ~1.5cm**
Aug 30 2000 03:23:22:700PM1000830020John GoetzShot 1000830020:
change outer gap to 2.0cm
0.8MW from D-port @ 0.6s
0.8MW from E-port @ 0.9s
0.4MW on each of J-port @ 1.2s

Results:
0.72MW from D-port; no faults
0.75MW from E-port; no faults
D and E-port performance about equal
0.37MW from J3; no faults
0.42MW from J4; no faults
no injections from J-port
J-port performance worse than D and E (0.5keV temp. increase versus 0.9keV for D,E)

**this was done at an outer gap of ~2.1cm**
Aug 30 2000 03:54:43:403PM1000830021John GoetzShot 1000830021:
change outer gap to 1.5cm
0.8MW from D-port @ 0.6s
0.8MW from E-port @ 0.9s
0.4MW on each of J-port @ 1.2s
change phase to 15 from 195 (should make [0,1,1,0]*!pi phasing)

Results:
0.77MW from D-port; no faults
0.79MW from E-port; no faults
D and E-port performance about equal
0.37MW from J3; no faults
0.42MW from J4; no faults
continuous multiple injections from everywhere along J-port antenna
no heating or neutron rate change with J-port
phasing was [0,1,1,0]*!pi

**this was done at an outer gap of ~1.4cm**
Aug 30 2000 04:10:58:810PM1000830022John GoetzShot 1000830022:
make a diverted plasma
1.0MW from D-port @ 0.7 to 1.4s
1.0MW from E-port @ 0.7 to 1.4s
0.4MW on each of J-port @ 1.0 to 1.2s
change phase to 195 from 15 (should make [0,1,0,1]*!pi phasing)

Results:
diverted discharge, multiple H-modes
1.0MW from D-port; no faults
0.94MW from E-port; one DC0 fault and a screen crowbar (Sergey's fix didn't work so well)
can't really tell which came first, the crowbar, the fault, the injection or the H->L transition
0.37MW from J3; one fault
0.42MW from J4; one fault
both faults occur at H->L transition (or the cause of??)


Aug 30 2000 04:30:38:857PM1000830023John GoetzShot 1000830023:
retune the antennas
make the outer gap a bit larger
1.0MW from D-port @ 0.7 to 1.4s
1.0MW from E-port @ 0.7 to 1.4s
0.4MW on each of J-port @ 1.0 to 1.2s

Results:
diverted discharge, multiple H-modes
0.93MW from D-port; no faults
0.45MW from E-port; one DC0 fault and a screen crowbar; this was still in L-mode
0.37MW from J3; no faults
0.42MW from J4; no faults
J antenna looks pretty quiet on this one

Aug 30 2000 04:52:59:030PM1000830024John GoetzShot 1000830024:
retune the antennas
1.0MW from D-port @ 0.7 to 1.4s
0.75MW from E-port @ 0.7 to 1.4s
0.45MW on each of J-port @ 1.0 to 1.2s

Results:
diverted discharge, multiple H-modes; early disruption (many injections)
0.97MW from D-port; no faults
0.73MW from E-port; no faults
0.43-.47MW from J3; three faults
0.44-.53MW from J4; three faults
J antenna looks nasty at the end of this one (at least on the TV)

Aug 30 2000 05:15:46:547PM1000830025John GoetzShot 1000830025:
retune E-port antenna
1.0-1.2MW from D-port @ 0.7 to 1.4s
0.75-0.85MW from E-port @ 0.7 to 1.4s
0.45MW on each of J-port @ 1.0 to 1.2s

Results:
diverted discharge, multiple H-modes
1.0-1.15MW from D-port; one fault
0.75-.82MW from E-port; no faults
0.42MW from J3; three faults
0.43MW from J4; two faults
lower H-port side of J antenna looks nasty (appears to be behind the screen)

Physics Operator Comments
Aug 30 2000 08:42:22:437AMSteve WolfeSet up shot 1 as an EF4-only test, IC_EF4U=3kA from -1.1sec to 1.0 sec
(previously saved as pcs$wolfe:pcs_1000830666).

Load/clean
do a coldstart
all matrices responding.
Aug 30 2000 08:42:32:577AMSteve WolfeEngineering Setup and Run Plan for 1000830

MP 268: ICRF Conditioning
SL: Goetz/Schilling
PO: wolfe

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

Engineering Setup:

ECDC overnight in Deuterium, stopping 1-2 hours before run.

Run begins at 9:00 and ends at 17:00.

Power system setup: Same as for 1000824002
Set OH1, OH2U and OH2L fizzle delays at 300ms
Set TF fizzle delay at 400 ms


Gas setup: B-Top 6 psi D2 Hybrid Enabled
B-side lower 1 psi Argon Hybrid DISABLED
B-side Upper As is HYBRID DISABLED
C-side 30 psi D2 Hybrid Enabled
J-bottom As is Hybrid DISABLED

The following Gate Valves should be ENABLED, assuming vacuum ok:
ECE, VUV

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

If the RF guys aren't here for first shot, we'll start with the 2sec, 3kA,
EF4-only shot; the attempt on 1000829032 didn't give a clean result, due to
induced current in EF3. Therefore, this test will be done with hybrid control,
using the reverse (positive) bridge. The EF4 coils must be fully cold for
this test. The fizzle detector should be moved to the end of the EF4 pulse
(1.0 sec) and all other supplies turned off; EF4 should be set up with the
usual limits. A 2 sec square pulse at 3kA (each coil) will be programmed in
PCS . If RF is ready for plasma, I'll sneak this test in later in the day.

The plasma run will start with a 1MA, 9e19, 5.2T limiter discharge similar to
1000824002, but with CLEARIN offset set at 12700 and CLEARIN waveform drawn to
-.015, to get it back to "real", nearly current-independent settings.

Most shots will be inner wall limited to avoid H-mode transitions. The program
will consist of
1.) power testing and conditioning for D, E, and J-port
2.) low-power ramps for D, E, and J
3.) power steps to do heating comparisons
4.) gap, density, I, and Bt scans

Aug 30 2000 09:00:33:763AM1000830001Steve WolfeShot#1- EF4 only test under hybrid control, for bp coil response test.
Shot went ok, EF3 induced current at ramp down

For shot#2, load 1MA, 9e19, 5.2T shot: prepared from shot 1000824002
with CLEARIN offset=12700 and redrawn waveform. Also, some minor tweaks
to early RCUR ramp, and startup from yesterday.
Aug 30 2000 09:29:12:357AM1000830002Steve WolfeShot#2- Try for 1MA limited plasma.
plasma, full length.
Looks good, but traq2 data corrupted means EFIT won't run
Run it from PCS data; note that this won't have the limiter coils.

Startup looks good, fast current rise.
RF ran on all 4 xmitters at ~.25MW each

No PCS changes for next shot

Aug 30 2000 09:44:16:013AM1000830003Steve WolfeShot#3- Repeat, increasing power
plasma, full length
rf up to ~.5MW D&E, .8MW J; looks clean.
Some heating visible on ECE, Prad not bad.
EFIT is ok this time, outer gap 1.65, inner bouncing from 0 to 5mm
H/D up to ~5% (from 2-3% on shot#2)
Aug 30 2000 09:54:22:483AM1000830004Steve WolfeShot#4- Repeat, increasing power
plasma, full length.
SOme neutrrion increase. 2pi show some injections
during J pulse; J was faulting at the 1.5MW level.
D&E look good at .75MW
H/D seems to be back down to 2-3%, but very noisy signal.

Next shot: No pcs changes, RF will back off on J
a bit.
Aug 30 2000 10:07:36:217AM1000830005Steve WolfeShot#5- Repeat, RF will back off on J a bit.
disrupted at 1.25 sec, during J pulse.
Big injection, movie shows it from the lower corner
on the H-port side.
Meanwhile, D & E ran clean at 1MW
H/D somewhere between 2 and 6%

Next shot: enable 20ms Ar puff at .35sec; then we can
blame JR retroactively.

I should probably drop the pre-puff after the disruption,
but I'll see if it will recover on it's own.
Aug 30 2000 10:28:04:077AM1000830006Steve WolfeShot#6- Repeat; enable 20ms Ar puff at .35sec.

plasma, disrupts at 1.36sec, a little later in the
J-port pulse. There's a little injection and then a
monster. There was also a small injection during D-port
pulse, at .86sec, but the plasam survived that without a
quiver.

Next shot, back J down a little more.
Aug 30 2000 10:46:34:433AM1000830007Steve WolfeShot#7- back J down a little more, to about 1MW.
plasma disrupts at 1.43sec, about 50msec longer;
do we consider this progress?
Prad had flattopped, then two injections.
Movie shows action in the same corner.

Next shot: change timing on D&E, leave J the same.
Aug 30 2000 11:11:38:357AM1000830008Steve WolfeShot#8- change timing on D&E, drop J to 800kW.

plasma, full length. Some activity in rampdown on H-alpha
and the density, but it survives.
J ran clean. E and D now going in that order; D had some
faulting at the 1.3MW level, E ran clean.

There is a small injection at 0.5, right after crossover.
Plasma recovers, but I'll have to watch it.

Next shot: No changes
Aug 30 2000 11:29:35:247AM1000830009Steve WolfeShot#9- repeat
plasma, full length.
The rampdown marfe or fin or whatever is getting stronger.
small (or not-so-small) injection at 0.31sec; no major effect.
All antennas ran clean at ~1MW level (j at .8).
EFIT claims we're increasing the outer gap in rampdown by
a couple cm; this isn't programmed that way, probably
the RCUR offset is wrong; the offset drops from 8000 to
5000 at 1.7 sec - at least one is wrong.

Next shot: Allow AB limiter jet D2 puff for Zweben-vision
Aug 30 2000 11:48:39:750AM1000830010Steve WolfeShot#10- RF up by 50kW each; Zweben puff enabled.
plasma, full length.
All RF ran clean. The j-port pulse is seen on the
midplane pressure as a rise of ~.15mtorr; others
not readily apparent.

In rampdown- two halpha bursts, no density rise.
The R effect may be due to EF2U going to zero,
OH1 feedforward voltage going to zero, or the
change in RCUR offset. Whichever, the plasma likes
the behavior.

H/D ~5%. Injection at .5sec is back.

Next shot: increase D&E a little; J left the same.

Aug 30 2000 12:08:42:107PM1000830011Steve WolfeShot#11: increase D&E a little; J left the same.

plasma, full length.
some injections from J, others ran clean

Next shot: change the RCUR offset after 1.7sec
from 5000 to 8000 (like the rest of the shot)
While I'm at it, chage the segment 2 title,
which had said "diverted" to "limited"
Aug 30 2000 12:27:44:747PM1000830012Steve WolfeShot#12: change the RCUR offset after 1.7sec
from 5000 to 8000 (like the rest of the shot)
While I'm at it, chage the segment 2 title,
which had said "diverted" to "limited"

plasma disrupted at 1.28sec (during J).
Didn't get to see the rampdown change.

Next shot: Do low power ramps on all antennas.
Aug 30 2000 12:56:24:593PM1000830013Steve WolfeShot#13: Do low power ramps on all antennas.

plasma, full length.
RCUR moves further in in rampdown than 11, still
has a break in slope at 1.75sec; EF2U still on until 1.85
EF4 reverse crossover starts around 1.72, lasts till 1.85;
could be related to that. That is also when the V_OH1 goes
from +100 to 0.

Next shot: make outer gap 5mm larger, per SL request.
Aug 30 2000 01:06:44:717PM1000830014Steve WolfeShot#14: Starting gap scan part of progran:
make outer gap 5mm larger: RCUR from .661 to .6585

plasma full length.
Note that on the previous shot, the rcur ramp during
rampdown was about 1.8cm in 475kA while all supplies
were on; this implies an error in RCUR offset of
~8500, with the offset set at +8000. I think the
actual offset should be close to zero!

Next shot: make the gap 1cm smaller.
Aug 30 2000 01:30:00:013PM1000830015Steve WolfeShot#15: Continuing gap scan part of progran:
make outer gap 1cm smaller: Try doing it by changing
the RCUR offset from 8000->3000, leaving programing
waveform the same!!! Note that this is going to give
a jerk at segment switch, and swing further out in
the last part of the current rise.

plasma, full length.
Got the gap change ok, and the rcur change in
rampdown is reduced by about half.

Next shot: decrease gap another 5mm.

Aug 30 2000 01:59:53:547PM1000830016Steve WolfeShot#16: Continuing gap scan part of program:
decrease gap another 5mm: Change RCUR offset in seg 2 to zero!
move initial rcur point in by 5mm to try to reduce jump
at seg switch. This ends up at .65, which seems too small? I hope
I'm going the right direction.

plasma, full length. Ok, it gave a 5mm gap, as requested,
but it swings out to zero at .4sec, then jumps in to 1cm
at .45. There's no offset change there, it's crossover.
I'll slow down the rcur outward motion so it asks to be
further inside at crossover. It takes a 5mm jump outward at
1.5sec, just at start of rampdown, that I don't understand,
but it now holds that position pretty well until supplies
start railing. This change seems to make the dynamic current
response of RCUR sensible, i.e. eliminate most sensitivity,
but I don't like the fact that you have to draw a value so
much less than what you want.

Next shot: Change rcur ramp before 0.5sec, no other change;
RF will increase power in their ramps.
Aug 30 2000 02:17:46:077PM1000830017Steve WolfeShot#17: Change rcur ramp before 0.5sec, no other change;
RF will increase power.

plasma, full length. RF back to flat pulses at ~.8MW.
Notice that IC_EF4 begins to ramp down at 1.5sec, and
EF2byEF4 at about 1.7sec, both going in the direction
to get us in trouble.
Jump at seg switch is getting us close to outer limiter.
Need to adjust that a little.

Next shot: increase gap by 5mm
try holding EF2byEF4 and IC_EF4 constant in
rampdown.
Aug 30 2000 02:36:40:513PM1000830018Steve WolfeShot#18: increase gap by 5mm, this time by changing rcur from .6585 to .656
also, drop initial seg 2 rcur point to .645 and try holding EF2byEF4 and
IC_EF4 constant in rampdown.

plasma, full length. 1.1cm outer gap.
J faulting some at end, some injections during j pulse.

EF2 still goes to zero at 1.7sec,
EF4 goes just to zero. Notice that EF4 must drop to keep
EF2 up, so my last adjustments were going in opposite directions.

Next shot: 5mm larger gap.
Aug 30 2000 03:05:48:653PM1000830019Steve WolfeShot#19: increase gap by another 5mm, rcur .656 -> .6535
try ramping ic_ef4 to zero at 1.5sec, leaving EF2byEF4 constant -2000,
to try holding EF2 on longer. This is all rather silly, since the
shots are ramping all the way down and lasting to 2sec anyway. If I
get the supplies to stay on I'll probably lose the rampdown and have
to draw a changing RCUR again to get it back.

plasma, full length. EF2's stayed on this time (barely).
1.5cm gap, as requested. Some inward motion in rampdown this time.
Ian's flux R is pretty flat, as is RMAGX; ROUT moves in by a cm.
It is coming off the inner wall as well, but only by 5mm; this may be
because we're moving the x-point up, away from the reference point.

Next shot: another 5mm

Aug 30 2000 03:21:02:593PM1000830020Steve WolfeShot#20: increase gap by another 5mm, rcur .6535->.651
I'm not changing the rampdown this time, except that the
rcur is changed throughout.

breakdown was rather late on the previous shot, 7msec.
still a fast current rise, Bz may be drifting up. I'm
leaving it alone.

plasma, full length. 2cm gap, as requested.

Next shot: back to 1.5cm gap, change the phase on J.

Aug 30 2000 03:47:17:153PM1000830021Steve WolfeShot#21: back to 1.5cm gap, change the phase on J.
PUt a 1cm inward ramp on CLEARIN between 1.5 and 2.0

plasma, full length, but with a big perturbation at
1.44 sec; the 2pi is up for the whole J-port pulse.
No heating at all from J on this shot.

The plasma now stays on the inner wall, and the
outer gap is nearly constant in rampdown until 1.75,
when it starts in again.

Next shot: run a diverted plasma, stack D&E
Aug 30 2000 04:09:41:607PM1000830022Steve WolfeShot#22: run a diverted plasma, stack D&E
CLEARIN from -.015 to +.005, RCUR from .6535 to .6635

plasma, 3 eda h-modes, disrupted at 1.26sec.
left gap=2cm, right=1cm.
E-faulted early, D&J were both on; power~1.75MW.
First H-mode had D&E up to nearly 2MW, Wmhd~115kJ

Next shot: increase outer gap by 6mm

Aug 30 2000 04:31:14:297PM1000830023Steve WolfeShot#23: increase outer gap by 6mm, rcur from .6635 to .6605

plasma, full length, multiple h-modes. numerous injections.
outer gap~1.5cm, inner gap~1.6 to 1.8cm. Need to pull RCUR in further
right at .23 when I start to pull the divertor, it's swinging out too far.
H/D is running around 5-9%, well up from the start of the day.

E-port dropped out very early, D&J each give about .8MW, not very steady,
for ~1.6MW total.

Next shot: adjust early part of RCUR program.
Aug 30 2000 04:46:18:607PM1000830024Steve WolfeShot#24: adjust early part of RCUR program (.258sec) inward.

plasma with H-modes, disrupted at 1.3sec.
Nice eda h-mode from .8 to 1.11sec, gets up to ~120kJ,
1.3e13 neutrons; between 1.7 (D+E) and 2.5MW (J as well)
An injection kills the h-mode shortly after J comes on.

Next shot: No PCS changes.
Aug 30 2000 05:02:10:060PM1000830025Steve WolfeShot#25: No PCS changes.

plasma, full length, h-modes.
Another .3sec long eda, ~110kJ, with D+E at 1.8MW
J comes on at 1sec, but doesn't seem to heat on this one.

Engineering Operator Comments
ShotTimeTypeStatusComment
108:57:34:467AMTestOkEF4 Reverse Test Only
209:14:19:030AMPlasmaOk
309:30:15:687AMPlasmaOk
409:44:26:373AMPlasmaOk
509:57:46:310AMPlasmaOk
610:18:20:310AMPlasmaOk
710:37:49:230AMPlasmaOk
810:58:27:827AMPlasmaOk
911:17:42:607AMPlasmaOk
1011:38:17:653AMPlasmaOk
1111:59:03:187AMPlasmaOk
1212:19:56:060PMPlasmaOk
1312:41:11:403PMPlasmaOk
1401:01:30:577PMPlasmaOk
1501:23:57:843PMPlasmaOk
1601:47:20:950PMPlasmaOk
1702:09:05:547PMPlasmaOk
1802:30:25:577PMPlasmaOk
1902:52:35:090PMPlasmaOk
2003:14:49:683PMPlasmaOk
2103:36:27:233PMPlasmaOk
2203:59:44:170PMPlasmaOk
2304:20:25:327PMPlasmaOk
2404:37:39:387PMPlasmaOk
2504:56:20:310PMPlasmaOk