Alcator C-Mod Run 1040429 Information

Miniproposals

Miniproposal: 361

Date Filed: 11/13/2003

Title: Identity experiments with JET on error field locked mode thresholds

First Author: T.C. Hender

Session Leader: T.C. Hender (shots 1-16)

Miniproposal: 389

Date Filed: 2/5/2004

Title: CNPA Testing and Calibration

First Author: Vincent Tang

Session Leader: Vincent Tang (shots 17-31)

Operators
Session leader(s):	T.C. Hender,Vincent Tang
Physics operator(s):	Robert Granetz
Engineering operator(s):	Unknown

Engineering Operator Run Comment
MP#371 or MP#389 or MP#386/Granetz//Hender/Wolfe

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Entered: Jul 7 2004 03:49:05:257PM

Author: T.C. Hender

Run 1040429 (AM)

MP361

SLs Hender and Wolfe
PO Granetz

The aim of the session was to complete the JET/C-Mod error field identity
experiments by getting LM thresholds at both (i) high density and (ii)
low density. In the event, due to the difficulties of operating at high
density only the first aim was (partially) achieved. The session
established (when combined with previous data) that in this JET
configuration at 1.27MA the detachment density limit is nl04~2.5e20. It
has been possible to operate well above this density (cf shot 1040408026)
but only with a continuous MARFE (which is probably not desirable). The
disruptions caused by the attempted high density operation led to a ~50%
fizzle rate. Shot 11 gave very useful data with no LM and an A-coil
current of 2.3kA at nl04~2.3e20. Likewise a locked mode was obtained close
to full A-coil current in shot 16 at nl04~2.1e20. Finally there is a
possible locked mode at full A-coil current in shot 13, which needs further
analysis. Overall this is probably as far as we can go in getting high
density data with large A-coil currents (and thus relatively smaller
contributions from the intrinsic field errors).

Entered: Jul 7 2004 03:49:05:443PM

Author: Vincent Tang

Run Summary:

This run was a continuation of 1040415; the idea was to run limited plasmas
to prevent H-modes so we could finish the RF/density scan for MP 389.

We had a lot of problems this afternoon; out of 15 shots, only 5 shots had
plasma with DNB. Of those 5 shots, only 3 had new data; 1 shot was a repeat
of 1040415006, and the other was not useful because of electronic problems.

Initially, we wanted to do a RF scan at ne_l04~3e19 from 1MW to 3.5MW;
however, we had to raise the density to ne_l~5e19 to prevent hard x-rays,
fizzles, and disruptions. We got a power scan at ne_l~5e19 from 1.6-2.7MW;
however, only the 1.6MW shot had noticeable DNB induced signal. The lower
signals for the higher power shots could be because of the significantly
lowered CX cross section for higher energy neutrals. In addition, compared
with 1040415, the DNB pulses were weak today. More analysis is needed.

The background signal during RF was significant. From what we can
infer, a large portion of this background could be neutral particles, and
potentially useful for determining the minority tail temperature.

With the new 1.5s DNB, the rest of the RF and density scan in MP 389 could
be easily accomplished.

Physics Operator Summaries

Entered: Jul 7 2004 04:36:50:147PM

Author: Robert Granetz

Physics operator summary for run 1040429 (Thursday):

MP 361 (con't): JET/C-Mod locked mode identity
and
MP 389 (con't): Compact Neutral Particle Analyzer (CNPA) testing

Session leaders: Hender/Wolfe and V. Tang
Physics operator: R. Granetz

Summary: MP 361 -- The machine didn't want to run at the high densities
required for this miniproposal. Every plasma disrupted, with very
large halo currents (250-300 kA) because of the JET shape (outer
strike point above divertor nose). There were also many fizzles,
since the base pressure remained very high due to the
disruptions. Despite these difficulties, we were able to get a
pair of data points at one of the desired parameter settings. See
Steve and Tim's summary for more physics details.

MP 389 -- The machine didn't want to run at the very low densities
required for this miniproposal, so we ran at a slightly higher
density of nl_04=0.5e20 m-2 (target). We also ran diverted during
the early part of the discharge, and then transitioned to
inner-wall limited in time for the RF and the DNB. Hard x-rays
were a problem for much of the low density operation. See Vincent's
summary for details of the CNPA measurements.

WE DISCOVERD DURING TODAY'S OPERATION THAT THE J-BOTTOM PIEZE
VALVE HAS A SMALL LEAK.

Scorecard: 20 plasmas
9 fizzles
1 dud (PF supplies crowbarred)
1 tests or no-power shot cycles
0 aborted and/or screwed up by computer problems
0 beam-into-gas calibration shots with B-field(s)
----------
31 total

-------------------------------------------------------------------------------
Engineering setup for Thursday, 29 Apr 2004

MP 361 (con't): JET/C-Mod locked mode identity
and either
MP 389 (con't): Compact Neutral Particle Analyzer (CNPA) testing
or
MP 386 (con't): Locked Mode threshold

Note: The 2nd half of the run day will do MP 389 IF THE DNB IS OPERATIONAL,
otherwise we will do MP 386.

Session leaders: Hender/Wolfe and (V. Tang and/or Hutchinson/Wolfe)
Physics operator: R. Granetz

Overnight ECDC in D2, stopping two hours before the run.

Run begins at 09:00 and ends at 17:00.

Power systems as on 1040413029
Note: Acoil configuration (-Btop +Dbot +Gtop -Jbot)
C-coil PLC limits set to 3 kA, 600 V. Start time set to 0.3 s, invert 2.0 s.
(note change in start time)

Gas Setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 40 psi D2 Hybrid enabled (PG1)*
leave B-side upper with 15 psi He3 Hybrid disabled
fill C-side with 40 psi D2 Hybrid enabled (PG3)
fill J-bot with 40 psi D2 Hybrid enabled (PG2)*
* Note non-standard setup on B-side lower and J-bot. *
* Note: no argon will be puffed today *

Disable NINJA

Enable the following gate valves, assuming no vacuum problems:
ECE, VUV, DNB

Necessary diagnostics:
ECE set for 6.3 T; DNB (for MP 389)

-------------------------------------------------------------------------------
RF Setup: None for MP 361;
D & J or E & J (but not both D & E) for MP 389;
None for MP 386;

Have J and (D or E) in Run-on by 08:00, ready for the afternoon.

-------------------------------------------------------------------------------
Run Plan for MP 361:

q95=3.2 (I=1.3MA, B=6.3T, "JET shape")

With ( -Btop+Dbot+Gtop-Jbot) trying to get LM data at high density:

Note that we have non-standard gas setup, so for every reload of an old shot
setup, we need to be careful that PG1 and PG2 programming is what we really
want! Also, this equilibrium seems to be prone to making the TCI feedback
fail, so we may want to run either nl_Zmeter or just pre-programmed gas puff
if it isn't better than it was last time.

1. Repeat 1040413029 but with a target of nl04=3x10^20m-2
(compared to 2.1 x10^20 in reference shot). No A-coil current on this
shot, in order to confirm no intrinsic locked mode forms.
Use all available piezo valves to get density up as early
as possible (including B-side lower - we don't need rotation data so we'll
punt the usual Argon puff.) Note that PG2 should be reconnected to J-bot
instead of B-side upper before the run (interface room change by Wolfe)

2. Repeat 1. With 2kA square in A-coil from 0.8s to
1.28s. And then vary A-coil current up and down to refine LM threshold.

3. If this going well (unlikely!) repeat 2. at nl04~4x10^20 m-2.

Then with(Btop-Dbot-Gtop+Jbot) [just reverse the supply leads] trying to get LM
data at low density:

4. Repeat 1040413013 (nl04~7e19) but with an Acoil=2kA square wave from 0.3 to
1.28s. Repeat with Acoil=2.5kA

5. Repeat 1040413010 (nl04~8.5e19) but with Acoil ramped linearly from 0A at
0.3s to 3.5kA at 1.28s (the aim of this shot is to always achieve sufficient
intrinsic error field compensation to make no locked mode).

Turn over to MP#389 or MP#386 at 13:00 or as soon thereafter as possible,
so remote session leader can get his dinner.

-----------------------
Run Plan for MP#389:

This run requires the DNB to be operational. If it is not, then do MP#386.

Start with 1040415006 (0.8 MA, 5.4 T, nl_04=0.3e20 m-2) except change it to
be inner-wall limited.

A-coil off.

Prf = 1 MW from J-port.

Fire the DNB during the RF.

Increase Prf shot-to-shot in 0.5 MW steps, up to 3.5 MW. The power should
come from D & J or E & J, BUT NOT BOTH D & E (to avoid the 0.5 MHz beat).

If we complete this, we'll go to higher density.

-----------------------
Run Plan for MP#386:

These shots will be at 5.4T, 1MA. Since the GPC2 is going to still be set for
high field, we'll be using the FRCECE for our core ECE signals.

Change Acoil configuration to (-Dtop +Dbot +Jtop -Jbot), i.e. reversed from
our "normal" connection.

1. Load 1040317025 and raise nl04 to 1.4e20 (remember to do the right thing
with PG1 and PG2 (which is probably to have them disabled). Might also
want to reduce the PG3 plenum pressure back to 30 psi. Set Acoil
current to 1200A (program 1700A). This is point {3} on Ian's graph.

2. Raise or lower Acoil current setting to bracket threshold.

3. Load seg 2 from 1030715027 aiming for nl04~2.5e19, Acoil turned off.
It will probably take a few shots to get the density down. The trick is
going to be to prevent the shot from locking early; starting with a higher
density and letting it drop seems better than having it low throughout (as
we did on 1040414033). Also probably want to have significant pg3 puff in
seg1. We expect a locked mode after .6sec with no A-coil current.

4a. If we don't get an intrinsic locked mode at step 3, turn on the A-coil
(still in the "adverse" direction and raise the current until we do. Ideally
we want to find the current that gives a locked mode at the time when oh1 is
close to 18kA.

4b. If we did get an intrinsic locked mode in step 3, reverse the A-coil
connection (just reverse the supply leads) to (+Dtop -Dbot -Jtop +Jbot).
Set A-coil current to 1000A (program 1500A). This is Ian's point {1}. We
expect this to lock. If it doesn't, decrease the Acoil current until it does;
if it does lock, increase acoil current to 2000A, which should be unlocked
(confirming the open green point on the graph).

5. Raise A-coil current to 3500A (program 4000A). This is Ian's point {2}.
This should again be locked. If it isn't, we're done; if it is, reduce current
to refine the upper bound of the stable region.

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

ECDC in D2 was done last night.

Hybrid coldstart done by the engineering group; no errors found

Loaded PCS segments 2,3,4 from shot 1040413029; use segment 2
This segment has NL_ZMETER enabled at a value of 1.0
Set PG2 (J-bot today, D2) to 100 V from t=0.4 to 1.3 s
Copied PG2 waveform to PG1 (B-side-lower, D2)
disabled A-coils (but programmed for 2500 A, t=0.80-1.28 s)
PCS segment 1 from shot 1040428001

Confirmed proper A-coil setup (-Btop +Dbot +Gtop -Jbot)

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

The start of the run is delayed while a leak check is done. A small leak
has been found on a mini-conflat on K-horizontal. It couldn't be bagged
off due to its inaccessibility.

Shot 01 -- Plasma. 1.25 MA, 6.3 T. Disrupted at t=0.61 s, as nl_04 was
shooting up to reach 2.5e20 m-2. I_halo_L=280 kA!!! Got a halo
current warning.

Next shot: switch to TCI density feedback, programmed to 3.0e20
m-2. Also increase early PG3 programming in segment 2.

Shot 02 -- Plasma. Another early disruption...multiple minor disruptions
starting at t=0.24. It's not taking the early gas very well.

Next shot: slow down the density rampup.

Shot 03 -- Plasma. Disrupted at t=0.69 s, at Ip=1.3 MA. No moly
injections. Density got to nl_04=2.7e20 m-2 before a series of
disruptions begin. I_halo_L=260 kA...these shots have the outer
strike point riding up to the nose of the outer divertor.

Next shot: slow down the density rampup even more.

Shot 04 -- Fizzle.

Next shot: reduce pre-fill puff to 13 ms (from 15 ms)

Shot 05 -- Plasma. Disrupted at t=0.80 s. I_halo_L=300 kA.

Next shot: slow down density rise prior to t=0.4 s, and lower
the ultimate density to nl_04=2.6e20 m-2 (from 3.0)

Shot 06 -- Fizzle.

Next shot: reduce pre-fill puff another 1 ms. Also enable density
feedback control of PG2 (J-Bot), in addition to PG3.

Shot 07 -- No-power shot cycle. EF3 breaker pulled out during check.

Shot 08 -- Plasma. Disrupted at t=0.88 s. Density makes it slightly above
the requested level. I_halo_L=240 kA.

Next shot: reduce PG1 to 50 volts after t=0.7 s. Also reduce
pre-fill another 1 ms (to 11 ms)

Shot 09 -- Fizzle. Base pressure is very high, presumably because of all
the disruptions.

Next shot: reduce nl_04 to 2.1e20 m-2. Also reduce pre-fill
puff to 9 ms.

Shot 10 -- Fizzle. Very high base pressure.

Next shot: reduce pre-fill another 2 ms (to 7 ms!) and add +10 A
to IC_EF4.

Shot 11 -- Plasma. Made it to t=1.28 s. I don't think there was any
locked mode. I_halo_L=235 kA.

Next shot: program A-coil current to 4 kA, same timing.

Shot 12 -- Fizzle. These disruptions are killing us.

Next shot: add -10 A to IC_EF4.

Shot 13 -- Plasma. Disrupted at t=1.08 s, but it's not clear whether or
not this was due to a locked mode. nl_04=2.35e20 m-2.

Next shot: turn on A-coil 0.1 s earlier (at t=0.7 s), reduce
nl_04 to 2.0e20 m-2 (from 2.1). Also some small Br0 and Bz0
tweaks.

Shot 14 -- Fizzle.

Next shot: undo the Br0 tweak

Shot 15 -- Plasma. Disrupted very early. Looks like injections and/or
dirt do it in starting around t=0.1 s.

Next shot: try again, no changes

Shot 16 -- Plasma. Disrupted at t=1.0 s. This time it looks like a locked
mode induced by the high A-coil current (approx 3500 A).
nl_04=2.1e20 m-2.

End of MP 361 for today.

Begin MP 389.

Next shot: Load segment 2 from 1040415006 (.8 MA, 5.4 T, 0.3e20 m-2)
Change to limited plasma (CLEARIN = -2 cm).
Move RCUR in by 7.5 mm (to avoid hitting outer limiter).
Re-patch A-coils to standard configuration.
Set A-coil current to 2500 A.
Disable B-side-lower and J-bottom gas valves.

Shot 17 -- Fizzle. Base pressure was 1.4e-5 torr before the DNB gate valve
opened.

Next shot: reduce pre-fill puff to just 5 ms.

Shot 18 -- Plasma. Good full-length shot. Ip=0.8 MA, Bt=5.5 T.
nl_04=0.35e19 m-2. Prf=1.0 MW from J-antenna. Inner wall
limited. Outer gap = 1.5 cm. Lots of moly at these low
densities. There was a burst of runaways at the very end of the
rampdown. Unfortunately, the DNB faulted.

Next shot: repeat for the DNB. Also program in some more
density late in the rampdown.

Shot 19 -- Plasma. Beam fired. Prf=1 MW. nl_04=0.32e20 m-2 (target).
Huge amount of hard x-rays.

Next shot: more early gas puffing

Note: since we're not using the B-side-lower and J-bottom gas valves, I
just asked that they be pumped out (they're already disabled). This
resulted in the base pressure dropping by more than an order of magnitude.
THE J-BOTTOM PIEZO VALVE APPARENTLY LEAKS!

I've also increased the pre-fill puff to 13 ms for the next shot.

Shot 20 -- Plasma. Short, dirty, disruptive. Startup has changed, now
that the base pressure is so much less.

Next shot: increase pre-fill puff to 16 ms; add -10 A to IC_EF4;
tweak early gas puffing some more.

Shot 21 -- Plasma. Short, dirty, disruptive. Some hard x-rays, but much
less than preceding shots.

Next shot: try going the other way with IC_EF4. Add +20 amps.

Shot 22 -- Fizzle.

Next shot: change CLEARIN and RCUR so that the plasma is
diverted until 0.7 s, then limited. Also tweak IC_EF4.

Shot 23 -- Plasma. Disrupted at t=0.82 s, shortly after going back to
inner wall limited. Still have some hard x-rays.

Next shot: increase nl_04=0.5e20 m-2. Some more early gas
and pre-fill puff tweaks.

Shot 24 -- Plasma. Full-length shot. Prf=1.65 MW (J). Small amount of
hard x-rays until late in the rampdown. nl_04 (target)=0.5e20 m-2.
No H-mode (because the plasma becomes limited before the RF
turns on).

Next shot: more RF power; tweak pre-fill puff.

Shot 25 -- Plasma. Full-length shot. Prf=2.1 MW (J). Lots of
hard x-rays until t=1 s. nl_04 (target)=0.5e20 m-2, but density
rises to 0.75e20 m-2 when the plasma becomes limited at t=0.7 s.
No H-mode (because the plasma becomes limited before the RF
turns on).

Next shot: more RF power. Tweak early gas puffing.

Shot 26 -- Plasma. Full-length shot. Prf=2.5 MW (E+J). Similar to
previous shot. No DNB.

Next shot: repeat for DNB.

Shot 27 -- Plasma. Full-length shot. Prf=2.75 MW (E+J). Similar to
previous shot. No DNB.

Next shot: repeat for DNB.

Shot 28 -- Fizzle.

Next shot: tweak Br0.

Shot 29 -- Plasma. Full-length shot. Prf=2.7 MW (E+J). Similar to
earlier shots. Got the beam this time.

Next shot: no PCS changes; same RF. Use larger aperture on the
CNPA detector.

Shot 30 -- Plasma. Full-length shot. Prf=2.6 MW (E+J). Similar to
earlier shots. Got the beam. Most of the hard x-rays are gone,
for no obvious reason.

Next shot: no PCS changes; reduce Prf to 1 MW

Shot 31 -- Dud. PF power supplies faulted before commutation.

End of run

Session Leader Comments

Apr 28 2004 08:10:14:937AM Steve Wolfe On Wed at 8:00AM I tried out the gnomemeeting connection to JET with Hender.
It works ok, provided I set the audio device to dsp0 (it was defaulting to dsp1).
Reducing the microphone level helps reduce static on his end. I should try
the echo cancellation/agc settings

Apr 29 2004 07:12:56:017AM Steve Wolfe Run Plan for MP 361:

q95=3.2 (I=1.3MA, B=6.3T, "JET shape")

With ( -Btop+Dbot+Gtop-Jbot) trying to get LM data at high density:

Note that we have non-standard gas setup, so for every reload of an old shot
setup, we need to be careful that PG1 and PG2 programming is what we really
want! Also, this equilibrium seems to be prone to making the TCI feedback
fail, so we may want to run either nl_Zmeter or just pre-programmed gas puff
if it isn't better than it was last time.

1. Repeat 1040413029 but with a target of nl04=3x10^20m-2
(compared to 2.1 x10^20 in reference shot). No A-coil current on this
shot, in order to confirm no intrinsic locked mode forms.
Use all available piezo valves to get density up as early
as possible (including B-side lower - we don't need rotation data so we'll
punt the usual Argon puff.) Note that PG2 should be reconnected to J-bot
instead of B-side upper before the run (interface room change by Wolfe)

2. Repeat 1. With 2kA square in A-coil from 0.8s to
1.28s. And then vary A-coil current up and down to refine LM threshold.

3. If this going well (unlikely!) repeat 2. at nl04~4x10^20 m-2.

Then with(Btop-Dbot-Gtop+Jbot) [just reverse the supply leads] trying to get LM
data at low density:

4. Repeat 1040413013 (nl04~7e19) but with an Acoil=2kA square wave from 0.3 to
1.28s. Repeat with Acoil=2.5kA

5. Repeat 1040413010 (nl04~8.5e19) but with Acoil ramped linearly from 0A at
0.3s to 3.5kA at 1.28s (the aim of this shot is to always achieve sufficient
intrinsic error field compensation to make no locked mode).

Turn over to MP#389 or MP#386 at 13:00 or as soon thereafter as possible,
so remote session leader can get his dinner.

Apr 29 2004 09:23:00:950AM Steve Wolfe Yesterday's leak has been isolated to K-side, on a mini-conflat
deep into the reentrant flange. It looks very hard to bag off.
We will probably have to live with this high 8 scale leak for today,
unless we're convinced it is hurting the breakdown.

Apr 29 2004 09:44:30:867AM 1040429001 Steve Wolfe Shot#1: Setup with B-side lower and J-bottom on pre-program and C-side on
nl_zmeter, program feedback for 1V on NL_ZMETER.

Disrupts at .6sec, possible locked mode at .6, but also an injection.
Not sure which is first.

Apr 29 2004 10:03:24:823AM 1040429002 Steve Wolfe Shot#2: Back to nl04 feedback.
short disruption.

next shot: slow down the density rise before crossover

Apr 29 2004 10:12:59:303AM 1040429003 Steve Wolfe Shot#3: slow down the density rise before crossover
another disruption at .69. density is rising fast.

next shot: slow down density rise some more, aim for 3e20 at 1.0sec

Apr 29 2004 10:22:37:640AM 1040429004 Steve Wolfe Shot#4: slow down density rise some more, aim for 3e20 at 1.0sec
fizzle

Apr 29 2004 10:52:04:930AM 1040429005 Steve Wolfe Shot#5: slow down density rise some more, aim for 3e20 at 1.0sec
disrupts at .8sec

Apr 29 2004 10:53:03:007AM 1040429006 Steve Wolfe Shot#6: slow down density rise some more, aim for 2.6e20 at 1.0sec

fizzle

Apr 29 2004 11:12:10:527AM 1040429007 Steve Wolfe Shot#7: slow down density rise some more, aim for 2.6e20 at 1.0sec

No power shot. EF3 breaker opened in check. Also TCI CO2 signal went low.

Apr 29 2004 11:27:50:583AM 1040429008 Steve Wolfe Shot#8: slow down density rise some more, aim for 2.6e20 at 1.0sec

Disrupts at .9sec, still on rising density

Apr 29 2004 11:44:00:170AM 1040429009 Steve Wolfe Shot#9: back off on b-side lower program puff
fizzle

Apr 29 2004 11:48:01:927AM 1040429010 Steve Wolfe Shot#10: punt the high density point. Go to 2.1e20 and turn on acoil,
trying to make a locked mode at between 0.8 and 1.0sec

fizzle

Apr 29 2004 12:06:14:120PM 1040429011 Steve Wolfe Shot#11: try again for 2.1e20 and turn on acoil,
trying to make a locked mode at between 0.8 and 1.0sec

disrupts at 1.28sec
no locked mode .

Apr 29 2004 12:15:36:240PM 1040429012 Steve Wolfe Shot#12: Raise A-coil to 3500 (4000 demand)
fizzle

Apr 29 2004 12:35:57:740PM 1040429013 Steve Wolfe Shot#13: Raise A-coil to 3500 (4000 demand)
plasma to 1.1sec
Can't really see a locked mode. Drop the density a bit
and turn acoil on earlier

Apr 29 2004 12:40:47:290PM 1040429014 Steve Wolfe Shot#14: Drop the density a bit
and turn acoil on earlier

fizzle

Apr 29 2004 01:02:07:507PM 1040429015 Steve Wolfe Shot#15: Drop the density to 2.1
and turn acoil on at .7sec, still 4000A demand

Early disruption, turns around at .1sec ???
big injection at .095sec

Try again

Apr 29 2004 01:15:48:790PM 1040429016 Steve Wolfe Shot#16: Drop the density to 2.1
and turn acoil on at .7sec, still 4000A demand

plasma disrupts at 1 sec
locked mode at .9sec

I think we got that point.

Turn the run over to Vincent and resume tomorrow morning
with the other acoil direction.

Apr 29 2004 01:33:35:183PM 1040429016 Vincent Tang Continuting MP389. First shot a duplicate of 1040415006, except inner limited.
Aperture set at 2.10/45. Attempt to reproduce 1040415006 CNPA signal.
Main focus today is power scan at ne_l4=0.3 & up wihtout going into H-Mode

Apr 29 2004 01:43:20:473PM 1040429017 Vincent Tang No plasma, but saw DNB induced signal on CNPA

Apr 29 2004 02:00:36:450PM 1040429018 Vincent Tang Next shot: repeat; Beam didn't fire. Density a little high, but good flattop. Good shot.
Got background neutral signal on CNPA

Apr 29 2004 02:14:01:183PM 1040429019 Vincent Tang Stronger signal during DNB, but only about 20% more. The large HXR background is probably the cause.

Apr 29 2004 02:32:29:953PM 1040429020 Vincent Tang We are moving to 1.5MW; even though we have not been able to completely reproduce the signal on 1040415006.

Apr 29 2004 02:46:39:907PM 1040429021 Vincent Tang disrupted at 0.5; will have to repeat.

In general, Zeff and soft & hard x-ray problems worse
than 1040415. DNB current is also lower. We might have
some difficutly with signal/background for the CNPA today.

Apr 29 2004 02:55:25:620PM 1040429022 Vincent Tang shot 22: fizzle; next shot will start diverted.

Apr 29 2004 03:27:00:343PM 1040429024 Vincent Tang Shot 24: Good shot, good signal during DNB. Energy spectrum is stronger and counts are greater.

Apr 29 2004 03:43:41:947PM 1040429025 Vincent Tang Shot 25: DNB signal not significantly above background.
Next shot: 2.5MW; We might try opening the aperture
a bit wider. The density on this shot was also higher;
The beam might have difficulty penetrating.

Apr 29 2004 03:51:15:773PM 1040429026 Vincent Tang Next shot: repeat; DNB didn't fire.

Apr 29 2004 04:05:11:727PM 1040429027 Vincent Tang Next shot: repeat; DNB didn't fire.

Apr 29 2004 04:13:22:800PM 1040429028 Vincent Tang Next shot: repeat, DNB fired, but fizzle.

Apr 29 2004 04:36:28:077PM 1040429029 Vincent Tang Next: repeat of 29, but with aperture opened to 3

Apr 29 2004 05:25:35:797PM 1040429029 Vincent Tang No significant DNB induced signal. Good background though.

Apr 29 2004 05:26:41:840PM 1040429030 Vincent Tang Larger aperture(or other unknown cause) overflooded digitizer system; no usable signal at all.

Physics Operator Comments

Apr 29 2004 08:34:18:330AM Robert Granetz ECDC in D2 was done last night.

Hybrid coldstart done by the engineering group; no errors found

Loaded PCS segments 2,3,4 from shot 1040413029; use segment 2
This segment has NL_ZMETER enabled at a value of 1.0
Set PG2 (J-bot today, D2) to 100 V from t=0.4 to 1.3 s
Copied PG2 waveform to PG1 (B-side-lower, D2)
disabled A-coils (but programmed for 2500 A, t=0.80-1.28 s)
PCS segment 1 from shot 1040428001

Confirmed proper A-coil setup (-Btop +Dbot +Gtop -Jbot)

Apr 29 2004 09:28:10:327AM Robert Granetz The start of the run is delayed while a leak check is done. A small leak
has been found on a mini-conflat on K-horizontal. It couldn't be bagged
off due to its inaccessibility.

Apr 29 2004 09:50:46:917AM 1040429001 Robert Granetz Shot 01 -- Plasma. 1.25 MA, 6.3 T. Disrupted at t=0.61 s, as nl_04 was
shooting up to reach 2.5e20 m-2. I_halo_L=280 kA!!! Got a halo
current warning.

Next shot: switch to TCI density feedback, programmed to 3.0e20
m-2. Also increase early PG3 programming in segment 2.

Apr 29 2004 10:02:43:903AM 1040429002 Robert Granetz Shot 02 -- Plasma. Another early disruption...multiple minor disruptions
starting at t=0.24. It's not taking the early gas very well.

Next shot: slow down the density rampup.

Apr 29 2004 10:14:30:313AM 1040429003 Robert Granetz Shot 03 -- Plasma. Disrupted at t=0.69 s, at Ip=1.3 MA. No moly
injections. Density got to nl_04=2.7e20 m-2 before a series of
disruptions begin. I_halo_L=260 kA...these shots have the outer
strike point riding up to the nose of the outer divertor.

Next shot: slow down the density rampup even more.

Apr 29 2004 10:24:15:933AM 1040429004 Robert Granetz Shot 04 -- Fizzle.

Next shot: reduce pre-fill puff to 13 ms (from 15 ms)

Apr 29 2004 10:53:04:943AM 1040429005 Robert Granetz Shot 05 -- Plasma. Disrupted at t=0.80 s. I_halo_L=300 kA.

Next shot: slow down density rise prior to t=0.4 s, and lower
the ultimate density to nl_04=2.6e20 m-2 (from 3.0)

Apr 29 2004 10:57:11:950AM 1040429006 Robert Granetz Shot 06 -- Fizzle.

Next shot: reduce pre-fill puff another 1 ms. Also enable density
feedback control of PG2 (J-Bot), in addition to PG3.

Apr 29 2004 11:16:23:250AM 1040429007 Robert Granetz Shot 07 -- No-power shot cycle. EF3 breaker pulled out during check.

Apr 29 2004 11:41:01:960AM 1040429008 Robert Granetz Shot 08 -- Plasma. Disrupted at t=0.88 s. Density makes it slightly above
the requested level. I_halo_L=240 kA.

Next shot: reduce PG1 to 50 volts after t=0.7 s. Also reduce
pre-fill another 1 ms (to 11 ms)

Apr 29 2004 11:52:39:073AM 1040429010 Robert Granetz Shot 10 -- Fizzle. Very high base pressure.

Next shot: reduce pre-fill another 2 ms (to 7 ms!) and add +10 A
to IC_EF4.

Apr 29 2004 12:07:23:163PM 1040429011 Robert Granetz Shot 11 -- Plasma. Made it to t=1.28 s. I don't think there was any
locked mode. I_halo_L=235 kA.

Next shot: program A-coil current to 4 kA, same timing.

Apr 29 2004 12:18:54:450PM 1040429012 Robert Granetz Shot 12 -- Fizzle. These disruptions are killing us.

Next shot: add -10 A to IC_EF4.

Apr 29 2004 12:36:31:673PM 1040429013 Robert Granetz Shot 13 -- Plasma. Disrupted at t=1.08 s, but it's not clear whether or
not this was due to a locked mode. nl_04=2.35e20 m-2.

Next shot: turn on A-coil 0.1 s earlier (at t=0.7 s), reduce
nl_04 to 2.0e20 m-2 (from 2.1). Also some small Br0 and Bz0
tweaks.

Apr 29 2004 12:46:20:810PM 1040429014 Robert Granetz Shot 14 -- Fizzle.

Next shot: undo the Br0 tweak

Apr 29 2004 01:15:42:507PM 1040429016 Robert Granetz Shot 16 -- Plasma. Disrupted at t=1.0 s. This time it looks like a locked
mode induced by the high A-coil current (approx 3500 A).
nl_04=2.1e20 m-2.

Apr 29 2004 01:26:28:683PM 1040429016 Robert Granetz Next shot: Load segment 2 from 1040415006 (.8 MA, 5.4 T, 0.3e20 m-2)
Change to limited plasma (CLEARIN = -2 cm).
Move RCUR in by 7.5 mm (to avoid hitting outer limiter).
Re-patch A-coils to standard configuration.
Set A-coil current to 2500 A.
Disable B-side-lower and J-bottom gas valves.

Apr 29 2004 05:06:51:427PM 1040429016 Robert Granetz End of MP 361 for today.

Begin MP 389 on the next shot

Apr 29 2004 01:44:05:160PM 1040429017 Robert Granetz Shot 17 -- Fizzle. Base pressure was 1.4e-5 torr before the DNB gate valve
opened.

Next shot: reduce pre-fill puff to just 5 ms.

Apr 29 2004 02:03:21:193PM 1040429018 Robert Granetz Shot 18 -- Plasma. Good full-length shot. Ip=0.8 MA, Bt=5.5 T.
nl_04=0.35e19 m-2. Prf=1.0 MW from J-antenna. Inner wall
limited. Outer gap = 1.5 cm. Lots of moly at these low
densities. There was a burst of runaways at the very end of the
rampdown. Unfortunately, the DNB faulted.

Next shot: repeat for the DNB. Also program in some more
density late in the rampdown.

Apr 29 2004 02:20:01:687PM 1040429019 Robert Granetz Shot 19 -- Plasma. Beam fired. Prf=1 MW. nl_04=0.32e20 m-2 (target).
Huge amount of hard x-rays.

Next shot: more early gas puffing

Note: since we're not using the B-side-lower and J-bottom gas valves, I
just asked that they be pumped out (they're already disabled). This
resulted in the base pressure dropping by more than an order of magnitude.
THE J-BOTTOM PIEZO VALVE APPARENTLY LEAKS!

I've also increased the pre-fill puff to 13 ms for the next shot.

Apr 29 2004 02:37:18:130PM 1040429020 Robert Granetz Shot 20 -- Plasma. Short, dirty, disruptive. Startup has changed, now
that the base pressure is so much less.

Next shot: increase pre-fill puff to 16 ms; add -10 A to IC_EF4;
tweak early gas puffing some more.

Apr 29 2004 02:49:49:447PM 1040429021 Robert Granetz Shot 21 -- Plasma. Short, dirty, disruptive. Some hard x-rays, but much
less than preceding shots.

Next shot: try going the other way with IC_EF4. Add +20 amps.

Apr 29 2004 03:00:11:627PM 1040429022 Robert Granetz Shot 22 -- Fizzle.

Next shot: change CLEARIN and RCUR so that the plasma is
diverted until 0.7 s, then limited. Also tweak IC_EF4.

Apr 29 2004 03:15:53:447PM 1040429023 Robert Granetz Shot 23 -- Plasma. Disrupted at t=0.82 s, shortly after going back to
inner wall limited. Still have some hard x-rays.

Next shot: increase nl_04=0.5e20 m-2. Some more early gas
and pre-fill puff tweaks.

Apr 29 2004 03:27:08:627PM 1040429024 Robert Granetz Shot 24 -- Plasma. Full-length shot. Prf=1.65 MW (J). Small amount of
hard x-rays until late in the rampdown. nl_04 (target)=0.5e20 m-2.
No H-mode (because the plasma becomes limited before the RF
turns on).

Next shot: more RF power; tweak pre-fill puff.

Apr 29 2004 03:40:35:953PM 1040429025 Robert Granetz Shot 25 -- Plasma. Full-length shot. Prf=2.1 MW (J). Lots of
hard x-rays until t=1 s. nl_04 (target)=0.5e20 m-2, but density
rises to 0.75e20 m-2 when the plasma becomes limited at t=0.7 s.
No H-mode (because the plasma becomes limited before the RF
turns on).

Next shot: more RF power. Tweak early gas puffing.

Apr 29 2004 03:52:56:707PM 1040429026 Robert Granetz Shot 26 -- Plasma. Full-length shot. Prf=2.5 MW (E+J). Similar to
previous shot. No DNB.

Next shot: repeat for DNB.

Apr 29 2004 04:00:24:377PM 1040429027 Robert Granetz Shot 27 -- Plasma. Full-length shot. Prf=2.75 MW (E+J). Similar to
previous shot. No DNB.

Next shot: repeat for DNB.

Apr 29 2004 04:13:18:080PM 1040429028 Robert Granetz Shot 28 -- Fizzle.

Next shot: tweak Br0.

Apr 29 2004 04:31:34:947PM 1040429029 Robert Granetz Shot 29 -- Plasma. Full-length shot. Prf=2.7 MW (E+J). Similar to
earlier shots. Got the beam this time.

Next shot: no PCS changes; same RF. Use larger aperture on the
CNPA detector.

Apr 29 2004 04:53:19:910PM 1040429030 Robert Granetz Shot 30 -- Plasma. Full-length shot. Prf=2.6 MW (E+J). Similar to
earlier shots. Got the beam. Most of the hard x-rays are gone,
for no obvious reason.

Next shot: no PCS changes; reduce Prf to 1 MW

Apr 29 2004 05:03:46:560PM 1040429031 Robert Granetz Shot 31 -- Dud. PF power supplies faulted before commutation.

End of run

Engineering Operator Comments

Shot Time Type Status Comment

1 09:35:20:157AM Plasma Ok

2 09:52:39:613AM Plasma Ok

3 10:05:51:100AM Plasma Ok

4 10:20:53:613AM Plasma Ok

5 10:34:55:783AM Plasma Ok

6 10:49:47:703AM Plasma Ok

7 11:05:29:400AM Plasma Ok

8 11:17:03:107AM Plasma Ok

9 11:32:54:057AM Plasma Ok

10 11:45:57:073AM Plasma Ok

11 11:58:55:167AM Plasma Ok

12 12:12:15:903PM Plasma Ok

13 12:24:49:357PM Plasma Ok

14 12:39:02:373PM Plasma Ok

15 12:56:32:190PM Plasma Ok

16 01:09:17:617PM Plasma Ok

17 01:39:00:797PM Plasma Ok

18 01:51:41:580PM Plasma Ok

19 02:04:15:253PM Plasma Ok

20 02:26:53:187PM Plasma Ok

21 02:40:07:593PM Plasma Ok

22 02:52:43:063PM Plasma Ok

23 03:05:20:537PM Plasma Ok

24 03:18:03:770PM Plasma Ok

25 03:31:20:367PM Plasma Ok

26 03:43:47:900PM Plasma Ok

27 03:56:23:997PM Plasma Ok

28 04:09:30:933PM Plasma Ok

29 04:23:31:713PM Plasma Ok

30 04:46:41:287PM Plasma Ok

31 04:59:14:930PM Plasma Bad OH2L comm fault at -0.7secs

Session Leader Comments
Apr 28 2004 08:10:14:937AM		Steve Wolfe	On Wed at 8:00AM I tried out the gnomemeeting connection to JET with Hender. It works ok, provided I set the audio device to dsp0 (it was defaulting to dsp1). Reducing the microphone level helps reduce static on his end. I should try the echo cancellation/agc settings
Apr 29 2004 07:12:56:017AM		Steve Wolfe	Run Plan for MP 361: q95=3.2 (I=1.3MA, B=6.3T, "JET shape") With ( -Btop+Dbot+Gtop-Jbot) trying to get LM data at high density: Note that we have non-standard gas setup, so for every reload of an old shot setup, we need to be careful that PG1 and PG2 programming is what we really want! Also, this equilibrium seems to be prone to making the TCI feedback fail, so we may want to run either nl_Zmeter or just pre-programmed gas puff if it isn't better than it was last time. 1. Repeat 1040413029 but with a target of nl04=3x10^20m-2 (compared to 2.1 x10^20 in reference shot). No A-coil current on this shot, in order to confirm no intrinsic locked mode forms. Use all available piezo valves to get density up as early as possible (including B-side lower - we don't need rotation data so we'll punt the usual Argon puff.) Note that PG2 should be reconnected to J-bot instead of B-side upper before the run (interface room change by Wolfe) 2. Repeat 1. With 2kA square in A-coil from 0.8s to 1.28s. And then vary A-coil current up and down to refine LM threshold. 3. If this going well (unlikely!) repeat 2. at nl04~4x10^20 m-2. Then with(Btop-Dbot-Gtop+Jbot) [just reverse the supply leads] trying to get LM data at low density: 4. Repeat 1040413013 (nl04~7e19) but with an Acoil=2kA square wave from 0.3 to 1.28s. Repeat with Acoil=2.5kA 5. Repeat 1040413010 (nl04~8.5e19) but with Acoil ramped linearly from 0A at 0.3s to 3.5kA at 1.28s (the aim of this shot is to always achieve sufficient intrinsic error field compensation to make no locked mode). Turn over to MP#389 or MP#386 at 13:00 or as soon thereafter as possible, so remote session leader can get his dinner.
Apr 29 2004 09:23:00:950AM		Steve Wolfe	Yesterday's leak has been isolated to K-side, on a mini-conflat deep into the reentrant flange. It looks very hard to bag off. We will probably have to live with this high 8 scale leak for today, unless we're convinced it is hurting the breakdown.
Apr 29 2004 09:44:30:867AM	1040429001	Steve Wolfe	Shot#1: Setup with B-side lower and J-bottom on pre-program and C-side on nl_zmeter, program feedback for 1V on NL_ZMETER. Disrupts at .6sec, possible locked mode at .6, but also an injection. Not sure which is first.
Apr 29 2004 10:03:24:823AM	1040429002	Steve Wolfe	Shot#2: Back to nl04 feedback. short disruption. next shot: slow down the density rise before crossover
Apr 29 2004 10:12:59:303AM	1040429003	Steve Wolfe	Shot#3: slow down the density rise before crossover another disruption at .69. density is rising fast. next shot: slow down density rise some more, aim for 3e20 at 1.0sec
Apr 29 2004 10:22:37:640AM	1040429004	Steve Wolfe	Shot#4: slow down density rise some more, aim for 3e20 at 1.0sec fizzle
Apr 29 2004 10:52:04:930AM	1040429005	Steve Wolfe	Shot#5: slow down density rise some more, aim for 3e20 at 1.0sec disrupts at .8sec
Apr 29 2004 10:53:03:007AM	1040429006	Steve Wolfe	Shot#6: slow down density rise some more, aim for 2.6e20 at 1.0sec fizzle
Apr 29 2004 11:12:10:527AM	1040429007	Steve Wolfe	Shot#7: slow down density rise some more, aim for 2.6e20 at 1.0sec No power shot. EF3 breaker opened in check. Also TCI CO2 signal went low.
Apr 29 2004 11:27:50:583AM	1040429008	Steve Wolfe	Shot#8: slow down density rise some more, aim for 2.6e20 at 1.0sec Disrupts at .9sec, still on rising density
Apr 29 2004 11:44:00:170AM	1040429009	Steve Wolfe	Shot#9: back off on b-side lower program puff fizzle
Apr 29 2004 11:48:01:927AM	1040429010	Steve Wolfe	Shot#10: punt the high density point. Go to 2.1e20 and turn on acoil, trying to make a locked mode at between 0.8 and 1.0sec fizzle
Apr 29 2004 12:06:14:120PM	1040429011	Steve Wolfe	Shot#11: try again for 2.1e20 and turn on acoil, trying to make a locked mode at between 0.8 and 1.0sec disrupts at 1.28sec no locked mode .
Apr 29 2004 12:15:36:240PM	1040429012	Steve Wolfe	Shot#12: Raise A-coil to 3500 (4000 demand) fizzle
Apr 29 2004 12:35:57:740PM	1040429013	Steve Wolfe	Shot#13: Raise A-coil to 3500 (4000 demand) plasma to 1.1sec Can't really see a locked mode. Drop the density a bit and turn acoil on earlier
Apr 29 2004 12:40:47:290PM	1040429014	Steve Wolfe	Shot#14: Drop the density a bit and turn acoil on earlier fizzle
Apr 29 2004 01:02:07:507PM	1040429015	Steve Wolfe	Shot#15: Drop the density to 2.1 and turn acoil on at .7sec, still 4000A demand Early disruption, turns around at .1sec ??? big injection at .095sec Try again
Apr 29 2004 01:15:48:790PM	1040429016	Steve Wolfe	Shot#16: Drop the density to 2.1 and turn acoil on at .7sec, still 4000A demand plasma disrupts at 1 sec locked mode at .9sec I think we got that point. Turn the run over to Vincent and resume tomorrow morning with the other acoil direction.
Apr 29 2004 01:33:35:183PM	1040429016	Vincent Tang	Continuting MP389. First shot a duplicate of 1040415006, except inner limited. Aperture set at 2.10/45. Attempt to reproduce 1040415006 CNPA signal. Main focus today is power scan at ne_l4=0.3 & up wihtout going into H-Mode
Apr 29 2004 01:43:20:473PM	1040429017	Vincent Tang	No plasma, but saw DNB induced signal on CNPA
Apr 29 2004 02:00:36:450PM	1040429018	Vincent Tang	Next shot: repeat; Beam didn't fire. Density a little high, but good flattop. Good shot. Got background neutral signal on CNPA
Apr 29 2004 02:14:01:183PM	1040429019	Vincent Tang	Stronger signal during DNB, but only about 20% more. The large HXR background is probably the cause.
Apr 29 2004 02:32:29:953PM	1040429020	Vincent Tang	We are moving to 1.5MW; even though we have not been able to completely reproduce the signal on 1040415006.
Apr 29 2004 02:46:39:907PM	1040429021	Vincent Tang	disrupted at 0.5; will have to repeat. In general, Zeff and soft & hard x-ray problems worse than 1040415. DNB current is also lower. We might have some difficutly with signal/background for the CNPA today.
Apr 29 2004 02:55:25:620PM	1040429022	Vincent Tang	shot 22: fizzle; next shot will start diverted.
Apr 29 2004 03:27:00:343PM	1040429024	Vincent Tang	Shot 24: Good shot, good signal during DNB. Energy spectrum is stronger and counts are greater.
Apr 29 2004 03:43:41:947PM	1040429025	Vincent Tang	Shot 25: DNB signal not significantly above background. Next shot: 2.5MW; We might try opening the aperture a bit wider. The density on this shot was also higher; The beam might have difficulty penetrating.
Apr 29 2004 03:51:15:773PM	1040429026	Vincent Tang	Next shot: repeat; DNB didn't fire.
Apr 29 2004 04:05:11:727PM	1040429027	Vincent Tang	Next shot: repeat; DNB didn't fire.
Apr 29 2004 04:13:22:800PM	1040429028	Vincent Tang	Next shot: repeat, DNB fired, but fizzle.
Apr 29 2004 04:36:28:077PM	1040429029	Vincent Tang	Next: repeat of 29, but with aperture opened to 3
Apr 29 2004 05:25:35:797PM	1040429029	Vincent Tang	No significant DNB induced signal. Good background though.
Apr 29 2004 05:26:41:840PM	1040429030	Vincent Tang	Larger aperture(or other unknown cause) overflooded digitizer system; no usable signal at all.

Physics Operator Comments
Apr 29 2004 08:34:18:330AM		Robert Granetz	ECDC in D2 was done last night. Hybrid coldstart done by the engineering group; no errors found Loaded PCS segments 2,3,4 from shot 1040413029; use segment 2 This segment has NL_ZMETER enabled at a value of 1.0 Set PG2 (J-bot today, D2) to 100 V from t=0.4 to 1.3 s Copied PG2 waveform to PG1 (B-side-lower, D2) disabled A-coils (but programmed for 2500 A, t=0.80-1.28 s) PCS segment 1 from shot 1040428001 Confirmed proper A-coil setup (-Btop +Dbot +Gtop -Jbot)
Apr 29 2004 09:28:10:327AM		Robert Granetz	The start of the run is delayed while a leak check is done. A small leak has been found on a mini-conflat on K-horizontal. It couldn't be bagged off due to its inaccessibility.
Apr 29 2004 09:50:46:917AM	1040429001	Robert Granetz	Shot 01 -- Plasma. 1.25 MA, 6.3 T. Disrupted at t=0.61 s, as nl_04 was shooting up to reach 2.5e20 m-2. I_halo_L=280 kA!!! Got a halo current warning. Next shot: switch to TCI density feedback, programmed to 3.0e20 m-2. Also increase early PG3 programming in segment 2.
Apr 29 2004 10:02:43:903AM	1040429002	Robert Granetz	Shot 02 -- Plasma. Another early disruption...multiple minor disruptions starting at t=0.24. It's not taking the early gas very well. Next shot: slow down the density rampup.
Apr 29 2004 10:14:30:313AM	1040429003	Robert Granetz	Shot 03 -- Plasma. Disrupted at t=0.69 s, at Ip=1.3 MA. No moly injections. Density got to nl_04=2.7e20 m-2 before a series of disruptions begin. I_halo_L=260 kA...these shots have the outer strike point riding up to the nose of the outer divertor. Next shot: slow down the density rampup even more.
Apr 29 2004 10:24:15:933AM	1040429004	Robert Granetz	Shot 04 -- Fizzle. Next shot: reduce pre-fill puff to 13 ms (from 15 ms)
Apr 29 2004 10:53:04:943AM	1040429005	Robert Granetz	Shot 05 -- Plasma. Disrupted at t=0.80 s. I_halo_L=300 kA. Next shot: slow down density rise prior to t=0.4 s, and lower the ultimate density to nl_04=2.6e20 m-2 (from 3.0)
Apr 29 2004 10:57:11:950AM	1040429006	Robert Granetz	Shot 06 -- Fizzle. Next shot: reduce pre-fill puff another 1 ms. Also enable density feedback control of PG2 (J-Bot), in addition to PG3.
Apr 29 2004 11:16:23:250AM	1040429007	Robert Granetz	Shot 07 -- No-power shot cycle. EF3 breaker pulled out during check.
Apr 29 2004 11:41:01:960AM	1040429008	Robert Granetz	Shot 08 -- Plasma. Disrupted at t=0.88 s. Density makes it slightly above the requested level. I_halo_L=240 kA. Next shot: reduce PG1 to 50 volts after t=0.7 s. Also reduce pre-fill another 1 ms (to 11 ms)
Apr 29 2004 11:52:39:073AM	1040429010	Robert Granetz	Shot 10 -- Fizzle. Very high base pressure. Next shot: reduce pre-fill another 2 ms (to 7 ms!) and add +10 A to IC_EF4.
Apr 29 2004 12:07:23:163PM	1040429011	Robert Granetz	Shot 11 -- Plasma. Made it to t=1.28 s. I don't think there was any locked mode. I_halo_L=235 kA. Next shot: program A-coil current to 4 kA, same timing.
Apr 29 2004 12:18:54:450PM	1040429012	Robert Granetz	Shot 12 -- Fizzle. These disruptions are killing us. Next shot: add -10 A to IC_EF4.
Apr 29 2004 12:36:31:673PM	1040429013	Robert Granetz	Shot 13 -- Plasma. Disrupted at t=1.08 s, but it's not clear whether or not this was due to a locked mode. nl_04=2.35e20 m-2. Next shot: turn on A-coil 0.1 s earlier (at t=0.7 s), reduce nl_04 to 2.0e20 m-2 (from 2.1). Also some small Br0 and Bz0 tweaks.
Apr 29 2004 12:46:20:810PM	1040429014	Robert Granetz	Shot 14 -- Fizzle. Next shot: undo the Br0 tweak
Apr 29 2004 01:15:42:507PM	1040429016	Robert Granetz	Shot 16 -- Plasma. Disrupted at t=1.0 s. This time it looks like a locked mode induced by the high A-coil current (approx 3500 A). nl_04=2.1e20 m-2.
Apr 29 2004 01:26:28:683PM	1040429016	Robert Granetz	Next shot: Load segment 2 from 1040415006 (.8 MA, 5.4 T, 0.3e20 m-2) Change to limited plasma (CLEARIN = -2 cm). Move RCUR in by 7.5 mm (to avoid hitting outer limiter). Re-patch A-coils to standard configuration. Set A-coil current to 2500 A. Disable B-side-lower and J-bottom gas valves.
Apr 29 2004 05:06:51:427PM	1040429016	Robert Granetz	End of MP 361 for today. Begin MP 389 on the next shot
Apr 29 2004 01:44:05:160PM	1040429017	Robert Granetz	Shot 17 -- Fizzle. Base pressure was 1.4e-5 torr before the DNB gate valve opened. Next shot: reduce pre-fill puff to just 5 ms.
Apr 29 2004 02:03:21:193PM	1040429018	Robert Granetz	Shot 18 -- Plasma. Good full-length shot. Ip=0.8 MA, Bt=5.5 T. nl_04=0.35e19 m-2. Prf=1.0 MW from J-antenna. Inner wall limited. Outer gap = 1.5 cm. Lots of moly at these low densities. There was a burst of runaways at the very end of the rampdown. Unfortunately, the DNB faulted. Next shot: repeat for the DNB. Also program in some more density late in the rampdown.
Apr 29 2004 02:20:01:687PM	1040429019	Robert Granetz	Shot 19 -- Plasma. Beam fired. Prf=1 MW. nl_04=0.32e20 m-2 (target). Huge amount of hard x-rays. Next shot: more early gas puffing Note: since we're not using the B-side-lower and J-bottom gas valves, I just asked that they be pumped out (they're already disabled). This resulted in the base pressure dropping by more than an order of magnitude. THE J-BOTTOM PIEZO VALVE APPARENTLY LEAKS! I've also increased the pre-fill puff to 13 ms for the next shot.
Apr 29 2004 02:37:18:130PM	1040429020	Robert Granetz	Shot 20 -- Plasma. Short, dirty, disruptive. Startup has changed, now that the base pressure is so much less. Next shot: increase pre-fill puff to 16 ms; add -10 A to IC_EF4; tweak early gas puffing some more.
Apr 29 2004 02:49:49:447PM	1040429021	Robert Granetz	Shot 21 -- Plasma. Short, dirty, disruptive. Some hard x-rays, but much less than preceding shots. Next shot: try going the other way with IC_EF4. Add +20 amps.
Apr 29 2004 03:00:11:627PM	1040429022	Robert Granetz	Shot 22 -- Fizzle. Next shot: change CLEARIN and RCUR so that the plasma is diverted until 0.7 s, then limited. Also tweak IC_EF4.
Apr 29 2004 03:15:53:447PM	1040429023	Robert Granetz	Shot 23 -- Plasma. Disrupted at t=0.82 s, shortly after going back to inner wall limited. Still have some hard x-rays. Next shot: increase nl_04=0.5e20 m-2. Some more early gas and pre-fill puff tweaks.
Apr 29 2004 03:27:08:627PM	1040429024	Robert Granetz	Shot 24 -- Plasma. Full-length shot. Prf=1.65 MW (J). Small amount of hard x-rays until late in the rampdown. nl_04 (target)=0.5e20 m-2. No H-mode (because the plasma becomes limited before the RF turns on). Next shot: more RF power; tweak pre-fill puff.
Apr 29 2004 03:40:35:953PM	1040429025	Robert Granetz	Shot 25 -- Plasma. Full-length shot. Prf=2.1 MW (J). Lots of hard x-rays until t=1 s. nl_04 (target)=0.5e20 m-2, but density rises to 0.75e20 m-2 when the plasma becomes limited at t=0.7 s. No H-mode (because the plasma becomes limited before the RF turns on). Next shot: more RF power. Tweak early gas puffing.
Apr 29 2004 03:52:56:707PM	1040429026	Robert Granetz	Shot 26 -- Plasma. Full-length shot. Prf=2.5 MW (E+J). Similar to previous shot. No DNB. Next shot: repeat for DNB.
Apr 29 2004 04:00:24:377PM	1040429027	Robert Granetz	Shot 27 -- Plasma. Full-length shot. Prf=2.75 MW (E+J). Similar to previous shot. No DNB. Next shot: repeat for DNB.
Apr 29 2004 04:13:18:080PM	1040429028	Robert Granetz	Shot 28 -- Fizzle. Next shot: tweak Br0.
Apr 29 2004 04:31:34:947PM	1040429029	Robert Granetz	Shot 29 -- Plasma. Full-length shot. Prf=2.7 MW (E+J). Similar to earlier shots. Got the beam this time. Next shot: no PCS changes; same RF. Use larger aperture on the CNPA detector.
Apr 29 2004 04:53:19:910PM	1040429030	Robert Granetz	Shot 30 -- Plasma. Full-length shot. Prf=2.6 MW (E+J). Similar to earlier shots. Got the beam. Most of the hard x-rays are gone, for no obvious reason. Next shot: no PCS changes; reduce Prf to 1 MW
Apr 29 2004 05:03:46:560PM	1040429031	Robert Granetz	Shot 31 -- Dud. PF power supplies faulted before commutation. End of run

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	09:35:20:157AM	Plasma	Ok
2	09:52:39:613AM	Plasma	Ok
3	10:05:51:100AM	Plasma	Ok
4	10:20:53:613AM	Plasma	Ok
5	10:34:55:783AM	Plasma	Ok
6	10:49:47:703AM	Plasma	Ok
7	11:05:29:400AM	Plasma	Ok
8	11:17:03:107AM	Plasma	Ok
9	11:32:54:057AM	Plasma	Ok
10	11:45:57:073AM	Plasma	Ok
11	11:58:55:167AM	Plasma	Ok
12	12:12:15:903PM	Plasma	Ok
13	12:24:49:357PM	Plasma	Ok
14	12:39:02:373PM	Plasma	Ok
15	12:56:32:190PM	Plasma	Ok
16	01:09:17:617PM	Plasma	Ok
17	01:39:00:797PM	Plasma	Ok
18	01:51:41:580PM	Plasma	Ok
19	02:04:15:253PM	Plasma	Ok
20	02:26:53:187PM	Plasma	Ok
21	02:40:07:593PM	Plasma	Ok
22	02:52:43:063PM	Plasma	Ok
23	03:05:20:537PM	Plasma	Ok
24	03:18:03:770PM	Plasma	Ok
25	03:31:20:367PM	Plasma	Ok
26	03:43:47:900PM	Plasma	Ok
27	03:56:23:997PM	Plasma	Ok
28	04:09:30:933PM	Plasma	Ok
29	04:23:31:713PM	Plasma	Ok
30	04:46:41:287PM	Plasma	Ok
31	04:59:14:930PM	Plasma	Bad	OH2L comm fault at -0.7secs