Alcator C-Mod Run 1050408 Information

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Miniproposals
Miniproposal:365
Date Filed:11/14/2003
Title:Inner wall screeing of impurities and deuterium
First Author:Bruce Lipschultz
Session Leader:Bruce Lipschultz (shots 21-31)
Miniproposal:412a
Date Filed: 1/19/2005
Title: Improved hydrogen-to-deuterium changeover using radiative terminations and disruptions
First Author:Dennis Whyte
Session Leader:Dennis Whyte (shots 1-16)
Session Leader:Bruce Lipschultz (shots 17-20)

Operators
Session leader(s):Dennis Whyte,Bruce Lipschultz,Bruce Lipschultz
Physics operator(s):Jim Irby
Engineering operator(s):Andy Pfeiffer,Ed Fitzgerald,Bill Parkin

Engineering Operator Run Comment
MP412 in the morning). The other is for MP365, in the afternoon SL(Bruce

Session Leader Plans
Entered: Apr 7 2005 03:03:27:610PM
Author: Bruce Lipschultz
Note that there are 2 plans contained herein: 1 for MP412 in the morning). The other is for MP365, in the afternoon

MP #412a: H/D recovery by planned disruptions

Goals: The plan is to examine the H/D recovery rate by planned
disruption after the H/D ratio has fallen to < 10%. The goals are to
1) Compare H/D recovery to the results from the early part of the cleanup campaign when
H/H+D ~ 50%, and
2) Provide fiducial shots on H/D recovery for comparison after the first boronization of the vessel walls.
3) Document effectiveness of using RF heated discharges

For these reasons we will first duplicate planned disruptions that were
used on the 1050211 run day. These disruptions worked well on
1050211 at removing a significant amount of H from the vessel wall, but
did not impose significant delays to operations due to fizzles.
We will compare both a q=2 and VDE
disruption. As before we operate with closed pumping valves and
examine the post-disruption gas content in the vessel. We will fuel only
D into the vessel for the discharges. It will also be helpful if
any improved diagnostic coverage of the disruption heat and radiation
loads were available compared to 1050211.

Setup requirements:
Shots to load from below
Need gate valve closure form the start
ICRF on some shots

Diagnostics: H/D, post-discharge RGA, bolometers, dust?

Plasma: Target plasmas LSN, 0.8 -1 MA

Requested ICRH: ~3 MW

Shots

shot 1. Repeat 1050211001, non-disrupting LSN 0.8 MA as fiducial.
2. q=2 disruption, OSP vertical target (1050211008)
3-5. Same, but with 2-3 MW ICRH. (2-3 shots to get RF tune)
6. q=2 disruption, ~ inner limited (1050211009)
7-8 Same with ICRH
9. VDE, downward into outboard divertor shelf (1050211018)
10. Repeat with ICRH
11. Upward going VDE (1050211014)
12. Repeat with ICRH
13. Repeat 1. as fiducial.


MP# 365: Inner wall screening of impurities and deuterium

Goals: The plan is to vary SSEP during a shot, from lower single-null to upper single-null (SSEP
=-0.5 to +0.5). N2 will be injected and we will monitor the N level in the core
using the McPherson VUV spectrograph. If the screening changes we will see the core N
level increase, and then decrease after we pass far enough towards upper single null. This
would be repeated for two inner wall gaps - 0.5 cm and 1.5 cm. If we can monitor the gas
injection simultaneously with a low ionization state of N that would be helpful. We will
simultaneously monitor both the Mo source rate at the wall and the core Mo levels using
HIREX.
The same test will also be done for injection of D.
Ideally this is done with maximum Mo source level at the inner wall. We would like to
plan for before a boronization with higher than usual current and lowish density.

Setup requirements:
Use as a shot 1050406026, but without RF. Adjust the inner gap to that specified below. No RF
Gate valve closed for shots
8 PSI N2 in NINJA

Diagnostics - HIREX Jr spectrograph, McPherson VUV spectrograph, Chromex spectrograph NII line at 463 nm), scanning probes.

Plasma - at least 1 MA if not higher. nl04 ~ 1.e20.

Shots
1. Set up shot with varying SSEP from -.5 to 0.5 over the time period 0.5 to 1.5 seconds (3 shots). Inner gap 0.5 cm.
2. inject N2 for one shot at 0.7 seconds. Start with an 0.1 sec puff. Vary the amount injected till a reasonable signal is seen on the McPherson. (3 shots)
3. Switch to D2 gas injection and repeat (2 shots)
4. Switch inner gap to 1.5 cm and repeat D2 injection (2 shots)
5. Switch to N2 gas injection and repeat (2 shots)

Physics Operators Plans
Entered: Apr 7 2005 03:25:59:570PM
Author: Jim Irby
Engineering Setup for Run 1050408

MP#412a Disruptive changeover (1/2 day-) Whyte/Lipschultz Irby

AND

MP#365 Inner wall screening of impurities Lipschultz "
and D2 (1/2 day+)


Overnight ECDC, bake at 60C

Run begins at 09:00 and ends at 17:00 (EDT)

Power systems as on 1050211001

A-coil in standard configuration (+Dtop -Dbot -Jtop +Jbot)
C-coil Start=0.3sec, Invert=2.0sec

Transmitters #1,2,3,4 in RUN-ON by 08:30

Gas setup:
fill B-top 6psi D2 Hybrid Enabled (PG4)
fill B-side lower 1psi Argon Hybrid Enabled (PG1)
leave B-side Upper alone Hybrid DISABLED (PG2)
fill B-main 30psi D2 Hybrid Enabled (PG3)

NINJA 8 psi Nitrogen


Enable: ECE, VUV, Z-bolo shutter

Setup to close gatevalves in pulse for 5 minutes.

Session Leader Summaries
Entered: Apr 8 2005 05:26:58:277PM
Author: Bruce Lipschultz

Session leader summary second half of 1050408 - MP MP# 365: Inner wall screening of impurities and deuterium

Goals: The plan is to vary SSEP during a shot, from lower single-null to upper single-null (SSEP
=-0.5 to +0.5). N2 will be injected and we will monitor the N level in the core
using the McPherson VUV spectrograph. If the screening changes we will see the core N
level increase, and then decrease after we pass far enough towards upper single null. This
would be repeated for two inner wall gaps - 0.5 cm and 1.5 cm. If we can monitor the gas
injection simultaneously with a low ionization state of N that would be helpful. We will
simultaneously monitor both the Mo source rate at the wall and the core Mo levels using
HIREX.
The same test will also be done for injection of D.
Ideally this is done with maximum Mo source level at the inner wall. We would like to
plan for before a boronization with higher than usual current and lowish density.

Results:
Had trouble getting going. Started around shot 21 - late start and it is hard to set up a constant inner gap while varying SSEP. We also had trouble identifying N lines we were happy about.

Got going well by shot 27, identified 2 N lines (see spectroscopy). N puff clearly shows up on Chromex as a constant N intensity during the puff. On the core lines it appears to drop, assuming we have identified the correct lines.

The core N inrtnesity does not seem to vary with SSEP, just comes up and then, after peaking drops with time. In other words even for comparing USN to LSN it is not symmetric. Less goes into the core from DN to USN. So one possibility is that we are cooling the edge too much with the puff to get the core signal up and that leads to changes in penetration.

Another aspect that clouds the results is the appearance of a MARFE like attributes on the D_alpha signal. Although not obvious on the cameras, there was a correlation of the core N intensity and the appearance of large fluctuations on the D_alpha. So the appearance of these flutuations appears to cause more N to go into the core.

We looked at HiJr Mo intensity. This did not seem affected by SSEP, dropping into the shot, probably due to a reduction in souurce from the N2 puff. The Chromex did not show any Mo source at the inner wall.

We did not get to the D2 puff.

Bottom line - no obvious effect of SSEP on screening of N2. We may have cooled the SOL too much. Brian will look at the SOL profiles taken on the last shot or two and comment on the profiles during the puff.
Entered: Apr 11 2005 12:08:33:833AM
Author: Dennis Whyte
Overall a successful experiment and we completed
the run plan. We were slowed down in the early part of the day by some
computer glitches. The machine ran well after these
problems were solved.

Obtained 8 disruption shots and 3 fiducial shots with no disruption. 3 disruptions
were obtained with ICRH heating of target plasma.

The plasma H/(H+D) was ~ 5% for most of the run day. This was clearly reflected in the
gas recovery, where H/(H+D) was ~ 10%, rather than the 40-70% seen during our
first run earlier in the campaign (1050211). Analysis shows that the
H/(H+D) ratios of the recovered gas correlates linearly to the target plasma
H/(H+D), but with a linear coefficent ~ 1.8. This is consistent with wall fuelling
dominating plasma content and that the disruption cleaning "samples" the
wall H/D ratio in a similar manner to the quiescent plasmas.

Almost all of the Hydrogen recovered today was in the form of HD, rather
than H2. Since only D2 is injected into C-Mod, this confirms the important role
that isotope exchange is playing in setting the H/D ratio.

The amount of gas released from the wall was less than seen on
our first run day. The best comparisons are downward VDE's that had
nearly identical target plasma condition (1050211018 vs. 1050408018). Today's
shot recovered only 10.2 Torr-L of gas, while the old shot recovered 34.5 Torr-L.
Both shots had about 13 Torr-L of D2 fuelling. If one works from the assumption
that the gas recovery is simply based on surface heating, then this suggests
that the total fuel content of the wall (or at least the lower divertor shelf
where this VDE hits) is a factor of 3.5 less than when we started conditioning.
This would be consistent with the idea conditioning actually drives down the
total hydrogenic concentration at the near-surface, which we believed started near 10-20%
based on ion beam analysis.

As in the first run day, there was a strong correlation between the
store energy/Te of the target plasma and the amount of gas recovered. The
two VDE target plasmas with ICRH heating recovered substantial (~40-50 Torr-L) of
gas from the wall.

Good fiducial shots were obtained without any disruptions. The wall
pumping is surprisingly strong on C-Mod, given that the Boron has
been mostly removed from the tile surfaces. For standard 0.8 MA
shots, roughly 1/2 of the D2 injected is left behind in the wall (~ 7 Torr-L /shot).
This is about the same as obtained on graphite-clad devices? The
reasons for this wall pumping, which does not appear to saturate, remain
under investigation.

Due to the disruption clearning the overall gas balance was positive for
the whole day (i.e. we recovered more gas than injected)

Total D injected (D2): 152 Torr-L
Total D recovered: 165 Torr-L
Totat H recovered: 25.2 Torr-L


The gas balance and post-discharge RGA worked very well today.
We confirmed the gas calibration accidentally In a few shots (e.g. 001) with gas
injection only and fizzles. The injected and retrieved D2 gas were
within 0.2 Torr-L , an acceptable uncertainty.


Physics Operator Summaries
Entered: Apr 8 2005 05:27:47:170PM
Author: Jim Irby
Data system problems caused loss of data on shot 03, and continued to
cause some slowdowns for a few more shots. A problem with the
matrox computer in the cell may have contributed to the problems. On
the other hand, we did get more information about he hydrogen
evolution from the programmed disruption discharges. VDE induced
disruptions were begun on shot 13. These discharges seemed to be
equally happy going up or down to disruption. On shot 16 Steve Wolfe
suggested we reduce clearin from .01 to .005 cm to make the plasma
more stable until we were ready to drive it down. This change seemed
to help; at least the next disruption did go down.

The second half of the run was tricky from the physop point of view
since it required keeping constant gaps while sweeping SSEP from -1.0
to 0.5 cm from 0.5 to 1.5 s. Several "tune-up" shots were required
with tweaks and ramps added to clearin. We should consider a better
way to make these adjustments.

We are still having some problems with the firewire triggers. During
the first half of the run they were triggering about 1/2 s early.

Without much icrf during this run, the RGA impurity levels remained
pretty low. H/(H+D) ranged from 4 to 7% during the day.



Tests 01,02,05,06,07,08 6
Duds 17,22 2
Fizzles 16 1
Plasmas 03,04,09,10,11,12,13,14,15,18,
19,20,21,23,24,25,26,27,28,29,30,31 22

Session Leader Comments
Apr 8 2005 10:15:55:297AM1050408001Dennis WhyteFiducial shot without plasma.
Good gas balance between injected (2.9 Torr-L)
compared to vessel inventory (2.7 Torr-L)
Apr 8 2005 09:49:14:670AM1050408004Dennis WhyteFiducial shot without disruption.
About 5 torr-L wall pumping. 12 torr-l in, 7 torr-l out
RGA shows basically D2
H/(H+D) ~ 4% and fairly constant in shot.

Apr 8 2005 10:56:42:703AM1050408009Dennis WhyteRepeat ohmic fiducial shot without disruption (Compared 004).
Injected D2 ~ 13.2 Torr-L
(pre-shot RGA had mostly M=28)
Post-shot: 5.4 Torr-L
RGA dominated by M=4 (D2)
Apr 8 2005 11:26:47:563AM1050408010Dennis Whyteq=2 disruption at 1.67 s
Ip started ramping down that decrease Wth to ~ 20 kJ
and Te ~ 0.9 keV. So fairly cold disruption.

Injected D2: 14.3 Torr-L
Recovered D2: 12 Torr-L

Post disruption RGA: dominated by D2

Apr 8 2005 11:42:23:390AM1050408011Dennis WhyteAttempted q=2 disruption
Had 3 MW ICRH, stored energy
peaked at 80 kJ but rapidly decreased
as the ICRH moved off resonance with the Bt rampdown.
Early disruption with q=3.4 at 0.95 s with Wth ~ 15 kJ

Density inreased and Te plummets to ~300 eV...caused
by ICRH into walls causing impurity injection?
By disruption P_oh= 2 MW...very resistive plasma.

Injected D2: 12.6 Torr-L
Recovered gas: 16 Torr-L

Post disruption RGA: dominated by D2 and Mass 6?
Apr 8 2005 11:53:35:517AM1050408012Dennis Whyteq=2 disruption
No ICRH

Disruption at 1.6 s at q=2 with inner wal limited
Wth ~ 20 kJ and Te ~ 900 eV
Plasma density jumped up due to
inner wall limiting, this pushed the Te down.
2pi bolometer suggest Prad ~ Poh

Injected D2: 16 Torr-L
Recovered gas: 11.5 Torr-L

Post disruption RGA: dominated Mass4 and Mass3
So HD still coming out of the wall
Apr 8 2005 12:04:28:267PM1050408013Dennis WhyteVDE disruption
No ICRH

Disruption at 1.05 s , LSN shape
Wth ~ 30 kJ and Te ~ 2 keV

Injected D2: 13 Torr-L
Recovered gas: Torr-L

Post disruption RGA: dominated Mass4 and Mass3
problem with RGA timing for preshot
Apr 8 2005 12:28:20:017PM1050408014Dennis WhyteVDE disruption...upward going VDE
3 MW ICRH

Disruption at 0.94 s , LSN shape
Wth ~ 90 kJ and Te ~ 3 keV

Injected D2: 9 Torr-L
Recovered gas: 34.6 Torr-L

Good gas recovery shot, clearly correlated to
stored energy and Te at disruption

Post disruption RGA: clear increase in H2
in comparison to previous shots today M2/M4 ~ 0.2
Also M=5 and M=6, likely D2H and D3 from ionization
in analyzer
Apr 8 2005 12:46:32:580PM1050408015Dennis WhyteVDE disruption, went down
2-3 MW ICRH

Disruption at 0.95 s , LSN shape
Wth ~ 92 kJ and Te ~ 3 keV

Injected D2: 10.7 Torr-L
Recovered gas: 51 Torr-L

Good gas recovery shot.

H/H+D ~ 0.05

M2/M4 ~ 0.1
Apr 8 2005 12:50:33:733PM1050408016Dennis WhyteFizzle (first of the day)
Apr 8 2005 01:11:44:093PM1050408017Bruce Lipschultzdud

This one may be useful as one calibration shot of the gas in vs out. We know the 4.06 m3 is a tad high. That is consitent what we see in the comparison of what went int owhat came out.

Also good to compare this shot to the fizzle which has a little plasma there at the beginning.
Apr 8 2005 01:34:49:080PM1050408018Bruce LipschultzVDE disruption, went down
No ICRH

Note: a small amount of Ar had been going in up till this shot. Turned off now.

Disruption at 1.04 s , LSN shape
Wth ~ 33 kJ and Te ~ 2.2 keV

Injected D2: 12.6 Torr-L
Recovered gas: 10 Torr-L

Good gas recovery shot.

RGA (mass 3)/(mass 4) ~ 2.1/9.2 ~ .23

RGA M2/M4 ~ 0.26/9.23 ~ .03

H/H+D plasma measurement ~ 6%

Next shot fiducial, reload shot 4
Apr 8 2005 01:55:10:527PM1050408019Bruce LipschultzVDE disruption, went down
No ICRH

Disruption at 1.04 s , LSN shape
Wth ~ 25 kJ and Te ~ 2.2 keV

Injected D2: 12.6 Torr-L
Recovered gas: 9.8 Torr-L

Good gas recovery shot.

Plasma h/(H+D) ~ 6%

RGA (mass 3)/(mass 4) ~ 2.1/9.2 ~ .2

M2/M4 ~ 0.26/9.23 ~ .03

Next shot try for fiducial again, reload shot 4
Apr 8 2005 01:55:13:400PM1050408020Bruce LipschultzFiducial shot
No ICRH

Disruption during current inversion, LSN shape
Stored energy around 30 kJ, Te=2 keV

Injected D2: 14.7 Torr-L
Recovered gas: 8.9 Torr-L

Good gas recovery shot.

Plasma h/(H+D) ~ 4%

RGA (mass 3)/(mass 4) ~ 2.1/9.2 ~ .2

M2/M4 ~ 0.26/9.23 ~ .02


Apr 8 2005 02:11:00:653PM1050408021Bruce LipschultzSetup of shot for MP 365

No gate valve closed

Lost intereferometer and all diag. with gate valves

inner gap too large (1 cm)

ssep sweep not implemented.

Apr 8 2005 02:33:20:527PM1050408022Bruce Lipschultzdud
Apr 8 2005 02:52:00:497PM1050408023Bruce Lipschultzshot still being tuned up (ssep roughly ok but gap too large and varying)
Apr 8 2005 03:11:34:120PM1050408024Bruce Lipschultzshot closer. N2 puffed at 0.7 seconds for 0.1s. However, MARFE obfuscates its effect. Have not found a good line on the McPherson to follow. COntinue to try puffs and get plasma tuned up (no MARFE, inner gap steady).

Apr 8 2005 03:29:24:793PM1050408025Bruce LipschultzShot equilibrium still there.
N2 puffed at 0.7 seconds for 0.1s.

Saw plenty of lines on Chromex. Brief signature on McPherson. 2 tl of gas injected. Back off on pressure and puff for 0.4 seconds next.
Apr 8 2005 03:51:41:997PM1050408026Bruce LipschultzShot pretty good
N2 puffed at 0.6 seconds for 0.4 but lower pressure (5 PSI)

Saw plenty of lines on Chromex. McPherson lines not clear. Need more N2. Back up on pressure to 7.5 PSI and keep 0.4 s pulselength.

ALso, change the starting SSEP to -1.
Apr 8 2005 04:28:00:183PM1050408027Bruce LipschultzShot pretty good

Same N2 puff. Chromex shows steady source. If we have the correct McPherson wavelength then things have changed. We no longer get the jump in McPherson signal. Try again with another wavelength next shot.

Apr 8 2005 04:51:37:170PM1050408029Bruce LipschultzShot pretty good

Same N2 puff. Chromex shows steady source. If we have the correct McPherson wavelength then things have changed. We no longer get the jump in McPherson signal. Try again with another wavelength next shot.

Apr 8 2005 04:55:42:997PM1050408030Bruce LipschultzShot pretty good

Increased gap to sslightly larger than 1 cm. MARFE-like event at around 1.1 sec clouding the issue. N2 puff affecting the density.

Chromex shows steady source. The McPherson story is not clear. Some shots it increases around SSEP =0, some not.

Apr 8 2005 05:14:13:560PM1050408031Bruce LipschultzShot pretty good

Lowered the density from nl04 =1 to 0.8 before the puff.

Left gap ~ 1 cm. MARFE-like event at around 1.1 sec again.


Physics Operator Comments
Apr 8 2005 08:22:56:143AMJim IrbyDid a load from 1050211001
Clearin offset set to zero in seg 2, 3, and 4.
IP offset set to zero in seg 2, 3, and 4.

loaded seg 1 from 1050407027 into seg 1

Apr 8 2005 08:27:28:597AM1050408001Jim IrbyLH video okay
Boron video okay
wide1 video okay
jant video NOT okay --- did a power cycle on the cameras

G-sider pressure gauge was off --- now on
Apr 8 2005 08:42:43:550AM1050408002Jim IrbyG-side gauge should be on
power cycle of cameras done

g-side working --- pressure high

jant, boron, wide1 are now working, but missing LH!
rebooting Sherman

Apr 8 2005 09:23:49:117AM1050408003Jim Irbyprepuff from 18 to 16 ms

PHYSOP screwup --- forgot to load/clean

plasma into rampdown

h/(h+d) at 2%

Apr 8 2005 09:36:20:297AM1050408004Jim Irbyloaded 1050211001

plasma into rampdown --- got density requested

boron camera looks great, but other cameras off by .5 s again

lost lots of data --- Josh and Tom unable to recover
Apr 8 2005 09:54:00:517AM1050408005Jim Irbyrepeat with all the data we hope

no luck --- no power cycle test

still data system problems
Apr 8 2005 10:38:34:140AM1050408007Jim IrbyAnother cycle test
Apr 8 2005 10:43:59:547AM1050408008Jim Irbycycle test --- data system looks much better

Apr 8 2005 10:55:56:127AM1050408009Jim IrbyGoing for plasma

plasma into rampdown


h/(h+d) at 4%
Apr 8 2005 11:42:13:390AM1050408010Jim Irbyloaded shot 1050211008 into seg 2

zeroed clearin and IP offsets

disruption at 1.66 s --- a little late

Apr 8 2005 11:30:10:047AM1050408011Jim IrbyTF rampdown started at 0.4 from 0.5 s

disruption at .93 s

3 MW of rf
Apr 8 2005 11:53:12:860AM1050408012Jim Irbyloaded 1050211009 into seg 2--- move to inner wall
zeroed clearin and ip

disruption at 1.63 s

lots of runaways


Apr 8 2005 12:07:04:703PM1050408013Jim Irbyloaded shot 1050211018 into seg 2 --- VDE disruption
cleared IP and clearin

disrupted at 1.02 s

Apr 8 2005 12:24:25:360PM1050408014Jim Irbyrepeat DPCS with 3 MW of rf

increased pg3 from 60 to 80 volts to help neuts/hards

disruption at 0.94 s

neuts/hards down

VDE went up
Apr 8 2005 12:35:10:843PM1050408015Jim Irbyrepeat

disruption at 0.94 s

Apr 8 2005 12:51:37:280PM1050408016Jim Irbydropped clearin from .01 to .005 cm --- make plasma a little more stable until we are ready
to drive it down.

no rf for this shot

fizzle
Apr 8 2005 01:07:32:390PM1050408017Jim Irbytry again

dud



Apr 8 2005 01:23:07:687PM1050408018Jim Irbyadded 2 ms of gas to prepuff

ef4 from -1345 to -1320 A

disruption at 1.03 s

disruption when down as we had hoped

Apr 8 2005 01:37:18:203PM1050408019Jim Irbyintended to load 1050408004 into seg 2 --- but forgot to load it!

repeat of shot 18

disruption at 1.03 s
Apr 8 2005 01:46:00:093PM1050408020Jim Irbyloaded 1050408004

plasma into rampdown
Apr 8 2005 02:16:59:357PM1050408021Jim Irbyloaded shot 1050406026 into seg2

clearin from 0.0 to -0.005 m

rcur from .656 to .658 m

plasma into rampdown

TCI gatevalves along with other diagnostic valves were closed !!

Apr 8 2005 02:32:55:277PM1050408022Jim Irbyloaded double null shot 1050405025 into seg 4

nl04 request to 1.e20 /m^2

clearin from 0.0 to -.0075 m

dud!

Apr 8 2005 02:55:55:543PM1050408023Jim Irbyprepuff increased by 2 ms

ef4 back to -1345 from -1320 A

plasma into rampdown

ssep did sweep has requested from -.5 to .5 cm from .5 to 1.5 s

clearin too large
Apr 8 2005 03:17:48:777PM1050408024Jim Irbyclearin ramped down to keep left gap smaller and more constant

plasma into rampdown

inner gap much closer but still need stronger ramp

Apr 8 2005 03:32:50:870PM1050408025Jim Irbydouble ramp added to clearin in attempt to keep it closer to 0.5 cm
added .3 cm to RCUR

gaps left and right not right
Apr 8 2005 03:44:24:760PM1050408026Jim Irbyrcur from .66 to .665 m

increased downward ramp on clearin after 0.8 s

plasma into rampdown

gaps look good

Apr 8 2005 04:02:43:403PM1050408026Jim Irbyssep ramp from -.01 to +.005 m from 0.5 to 1.5 s

plasma into rampdown

left gap a little too close from 1 to 1.2 s

Apr 8 2005 04:14:32:887PM1050408028Jim Irbyincreased clearin from 1 to 1.2 s

prop gain in nl_04 from 8 to 9

plasma into rampdown

over comp on left gap --- will reduce next shot

Apr 8 2005 04:31:14:510PM1050408029Jim Irbyreduced upward jump in clearin from 1 to 1.2 s

added 1 ms to prepuff gas --- fields still look good

plasma into rampdown

clearin better

Apr 8 2005 04:51:00:967PM1050408030Jim Irbyadded .005 m to clearin to increase the inner gap

plasma into rampdown

clearin better

Apr 8 2005 05:26:49:760PM1050408031Jim Irbydensity request from 1e20 to 7e19 /m^2

disruption at 1.29 s

Engineering Operator Comments
ShotTimeTypeStatusComment
108:16:24:100AMTestOkcycle-test
208:29:05:223AMTestOk
309:01:53:283AMPlasmaOk
409:18:53:927AMPlasmaOk
710:08:58:407AMTestBad
810:35:09:080AMTestOk
910:44:37:127AMPlasmaOk
1011:03:58:690AMPlasmaOk
1111:21:17:970AMPlasmaOk
1211:42:24:313AMPlasmaOk
1311:54:52:440AMPlasmaOk
1412:07:20:343PMPlasmaOk
1512:29:21:703PMPlasmaOk
1612:45:07:377PMPlasmaOk
1701:00:16:373PMPlasmaOk
1801:13:22:470PMPlasmaOk
1901:25:54:313PMPlasmaOk
2001:38:18:377PMPlasmaOk
2101:58:40:870PMPlasmaOk
2202:27:14:997PMPlasmaOk
2302:39:49:247PMPlasmaOk
2402:57:33:903PMPlasmaOk
2503:19:41:403PMPlasmaOk
2603:36:03:683PMPlasmaOk
2703:51:59:090PMPlasmaOk
2804:06:29:590PMPlasmaOk
2904:25:01:497PMPlasmaOk
3004:38:01:997PMPlasmaOk
3104:52:11:963PMPlasmaOk