Alcator C-Mod Run 1080423 Information

Miniproposals

Miniproposal: 536

Date Filed: 2/21/2008

Title: Evaluation of FWEH, FWCD and MCCD

First Author: Steve Wukitch

Session Leader: Steve Wukitch (shots 1-28)

Operators
Session leader(s):	Steve Wukitch
Physics operator(s):	Ian Hutchinson
Engineering operator(s):	Andy Pfeiffer,Bill Byford

Engineering Operator Run Comment
MP536 Evaluation of FWEH, FWCD and MCCD session leader Steve Wukitch phy

Session Leader Plans

Entered: Apr 22 2008 11:12:48:940PM

Author: Steve Wukitch

Run Plan: MP536 Evaluation of FWEH, FWCD and MCCD

1. Establish discharge using 1080125026 as a basis with 2.5 MW from D+E
antennas and 2-3 MW from J in heating phase after the H-mode has
formed. (3-4 shots)

Scan plasma density, BT, and plasma current to maximize FWEH by
maximizing electron beta. (Lower BT to 5 T; scan Ip; scan density) 10
shots

If necessary, investigate discharges like 1080409030 (USN, Ip~1.3 MA)
to maximize plasma beta and FW absorption.

2. If significant electron absorption is observed then: Scan the J
antenna phase in discharges with 2.5 MW from D+E, 2.5 MW from J
antenna. Phases to be used are [0,pi,pi,0] (heating phase),
[0,pi/2,pi,3/2pi], and [0,pi/2,pi,-3/2pi]. (6 shots)

3. If successful at highest power level, utilized 1.5 MW from J antenna
into same target plasma. (3 shots).

If direct electron absorption is a bust, then evaluate central MCCD
both in the current flat top and ramp-up.

4. Establish discharge using best discharge from step 1 as a basis
with 2.5 MW from D+E antennas and 2.5 MW from J in heating phase
with the modulated power to determine location of the deposition
profile. (3 shots)

5. Scan the J antenna phase in discharges with 2.5 MW from D+E, 2.5-3 MW
from J antenna, and BT~5.5. Phases to be used are [0,pi,pi,0] (heating
phase), [0,pi/2,pi,3/2 ], and [0,pi/2,pi,-3/2pi]. (6 shots)

Physics Operators Plans

Entered: Apr 22 2008 10:48:36:690PM

Author: Steve Wukitch

-----------------
Engineering Setup
-----------------

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

Power systems as on: 1080125026

Acoil: +Dtop -Dbot -Jtop +Jbot (standard) Hybrid Enabled

Gas setup:

Fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar Hybrid DISABLED (PG1)
fill B-side upper with 15 psi He3 Hybrid DISABLED (PG2)
fill B-main (C-side) with 40 psi D2 Hybrid enabled (PG3)
fill NINJA with 10 psi D2 DISABLED

Enable gatevalves and shutters: ECE, VUV, DNB, Z-bolo

Torvac gatevalve toggle (yes/no): no

Boronization(yes/no): yes
Overnight ECDC (yes/no): yes
ICRF(yes/no): yes
LH(yes/no): no
DNB(yes/no): yes but likely not operational
Cryopump (yes/no): yes, but later in run

Vessel temperature: 60/60/60 for as long as is consistent with cooldown

Boronization
------------
20% diborane/80% helium
TC6 foreline pressure: 50 mTorr
rmin/rdwell/rmax: 44/75/80 cm
tdwell/tsweep: 60 /120s
EF4 current: 200 A
Pressure change in the bottle: 60 psi

Post boronization ECDC
----------------------------
1st Gas Setup:
Gas: helium
sweep: 44/103/45 cm
tdwell/tsweep 20/120 s
Pressure: 5e-5 Torr
Duration: 1 hr

2nd Gas Setup
Gas: d2
sweep: 44/103/45cm
tdwell/tsweep: 20/120 s
Pressure: 2e-4 Torr
Duration: 1hr

Session Leader Summaries

Entered: Apr 23 2008 05:13:54:497PM

Author: Steve Wukitch

Despite some PLC trouble, we were able to find evidence of fast wave
electron heating, 1080423018 is the trophy discharge. The discharge
required was an USN discharge at 5.2 T and plasma current 1 MA. The
target temperature was ~4.5 keV at the top of the sawteeth; otherwise
the heating was very weak. In current drive phase, the plasma
temperature decreased with FW power applied suggesting poor wave
damping. Impurity production with the RF was quite more substantial
than the H minority heating from D+E antennas.

Physics Operator Summaries

Entered: Apr 23 2008 05:12:39:277PM

Author: Ian Hutchinson

Today's run showed that there is an incipient vertical stability problem with
double/upper null shots (up to 15). Although n/n_c is quite moderate, there
is a ~60Hz oscillation that appears to be strongly affected by small changes
in the fast P gain. The oscillation only became a problem for the highest
current where it tends to rail the chopper and led to several VDEs.

The upper null plasma from shot 17 on did not have that problem.

An hour was lost to a fault in the torvac PLC.

Scorecard
_________

Shot,Duration(s),Ipmax(MA),Result Shot,Duration(s),Ipmax,Result | 01 1.939 0.799 Plasma | 02 1.287 0.814 Plasma | | 03 1.297 0.822 Plasma | 04 0.454 0.673 Plasma | | 05 0.557 0.811 Plasma | 06 0.545 0.811 Plasma | | 07 1.984 0.828 Plasma | 08 0.000 0.061 Plasma | | 09 1.979 0.833 Plasma | 10 1.980 0.821 Plasma | | 11 1.982 1.021 Plasma | 12 1.983 1.024 Plasma | | 13 1.981 1.010 Plasma | 14 1.211 1.264 Plasma | | 15 1.007 1.208 Plasma | 16 0.000 0.052 Dud | | 17 1.961 1.024 Plasma | 18 1.274 1.064 Plasma | | 19 1.964 1.025 Plasma | 20 0.376 0.808 Plasma | | 21 1.962 1.023 Plasma | 22 1.097 1.058 Plasma | | 23 1.964 1.021 Plasma | 24 1.965 1.023 Plasma | | 25 1.964 1.025 Plasma | 26 1.332 1.035 Plasma | | 27 1.962 1.014 Plasma | 28 1.963 1.019 Plasma | Date 1080423: 28 shots. 27 plasmas. 0 fizzles. 1 duds. 0 System Error. (Plasma = Ip gt 60.0 kA Dud = H_alpha lt 0.40 V) Total plasma duration: 39.97 s (exceeding -80 kA)

Session Leader Comments

Apr 23 2008 09:26:42:343AM 1080423001 Steve Wukitch 001 Bt=5.4 T,Ip= 0.8 MA, nl04=0.9e20 /m^2, LSN, gap 1.0 cm.
D: 1.2 MW, [0.70, 1.30] sec
E: 1.2 MW, [0.70, 1.30] sec
J: 2.2 MW, [0.80, 1.30] sec
Result: density was too high
D: max faults
E: max faults
J: max faults
Next: lower target density
aim for better RF power

Apr 23 2008 09:52:25:287AM 1080423002 Steve Wukitch 002 Bt=5.4 T,Ip= 0.8 MA, nl04=0.9e20 /m^2, LSN, gap 1.0 cm.
D: 1.2 MW, [0.70, 1.30] sec
E: 1.2 MW, [0.70, 1.30] sec
J: 2.2 MW, [0.80, 1.30] sec
Result:
D: max faults
E: max faults, but better
J: max faults (improved at end of pulse)
Note: target density is better
lots of density with RF
cell access to address camera issue
next: adjust J start time to 1 sec

Apr 23 2008 10:01:50:327AM 1080423003 Steve Wukitch 003 Bt=5.4 T,Ip= 0.8 MA, nl04=0.7e20 /m^2, LSN, gap 1.0 cm.
D: 1.2 MW, [0.70, 1.30] sec
E: 1.2 MW, [0.70, 1.30] sec
J: 2.2 MW, [1., 1.30] sec
Result:
D: ran 2 faults
E: ran 5 faults
J: ran 7 faults (improving towards end of pulse)
Note: temperature too low at start of J antenna for any fast wave damping
still evolving density with D+E but cryopump is pumping
if this H/D is too be believed, H is too low
next: repeat, monitor density evolution and H fraction

Apr 23 2008 10:02:05:637AM 1080423004 Steve Wukitch early disruption

Apr 23 2008 11:10:04:987AM 1080423005 Steve Wukitch early disruption

Apr 23 2008 11:10:15:860AM 1080423006 Steve Wukitch early disruption

reload 003

Apr 23 2008 11:19:51:807AM 1080423007 Steve Wukitch 007 Bt=5.4 T,Ip= 0.8 MA, nl04=0.6e20 /m^2, LSN to USN
D: 1.2 MW, [0.70, 1.30] sec
E: 1.2 MW, [0.70, 1.30] sec
J: 2.2 MW, [1., 1.30] sec
Result:
D: max faults
E: ran 1 fault
J: ran 10 faults
Note: temperature still too low at start of J antenna but interesting transition at 1.18 s and another at 1.23 s
still evolving density with D+E but cryopump is pumping
H/D indicates 4%
next: move D+E start to 0.6 s and raise power to 2.5 MW

Apr 23 2008 11:25:45:357AM 1080423008 Steve Wukitch fizzle

Apr 23 2008 12:04:33:900PM 1080423009 Steve Wukitch 009 Bt=5.4 T,Ip= 0.8 MA, nl04=0.6e20 /m^2, LSN to USN
D: 1.2 MW, [0.70, 1.30] sec
E: 1.5 MW, [0.70, 1.30] sec
J: 2.2 MW, [1., 1.30] sec
Result:
D: ran 1 fault
E: ran 2 faults
J: ran 3 faults
Note: better target but no real significant heating
next: lower B to 5.2 T

Apr 23 2008 11:58:05:940AM 1080423010 Steve Wukitch 010 Bt=5.2 T,Ip= 0.8 MA, nl04=0.6e20 /m^2, LSN to USN
D: 1.2 MW, [0.60, 1.20] sec
E: 1.5 MW, [0.70, 1.20] sec
J: 2.5 MW, [0.8, 1.20] sec
Result:
D: ran
E: ran
J: ran overload
Note: decent target (central Te dropped from 3.5 to 3 at top of
sawteeth and no real significant heating observed with J
next: raise plasma current to 1 MA

Apr 23 2008 12:22:50:773PM 1080423011 Steve Wukitch 011 Bt=5.2 T,Ip= 1 MA, nl04=0.8e20 /m^2, LSN to USN
D: 1.2 MW, [0.60, 1.20] sec
E: 1.5 MW, [0.70, 1.20] sec
J: 2.2 MW, [0.8, 1.20] sec
Result:
D: screen overload
E: max faults
J: max faults
Note: good target (central Te to 3.8 at top of sawteeth)
next: repeat with better RF

Apr 23 2008 12:28:41:217PM 1080423012 Steve Wukitch 012 Bt=5.2 T,Ip= 1 MA, nl04=0.8e20 /m^2, LSN to USN
D: 1.2 MW, [0.60, 1.20] sec
E: 1.5 MW, [0.60, 1.20] sec
J: 2.2 MW, [0.8, 1.10] sec
Result:
D: ran briefly then xbar and screen overload
E: ran multiple faults
J: ran with faults
next: repeat with better RF - back off D

Apr 23 2008 12:38:04:240PM 1080423013 Steve Wukitch 013 Bt=5.2 T,Ip= 1 MA, nl04=0.8e20 /m^2, LSN to USN
D: 1 MW, [0.60, 1.20] sec
E: 1.5 MW, [0.60, 1.20] sec
J: 2.2 MW, [0.8, 1.10] sec
Result:
D: ran 1 fault
E: did not run - silent fault from FFT
J: ran 2 faults
next: this time with E antenna

Apr 23 2008 01:26:53:823PM 1080423014 Steve Wukitch 014 Bt=5 T,Ip= 1.2 MA, nl04=0.8e20 /m^2, LSN to USN
D: 1 MW, [0.60, 1.20] sec
E: 1.6 MW, [0.60, 1.20] sec
J: 2.2 MW, [0.8, 1.10] sec
Result: not a better target
D: ran 7 faults
E: ran 9 faults
J: ran
next: return to 5.2 T

Apr 23 2008 02:23:01:163PM 1080423015 Steve Wukitch 015 Bt=5.2 T,Ip= 1.2 MA, nl04=0.7e20 /m^2, LSN to USN
D: 1 MW, [0.60, 1.20] sec
E: 1.6 MW, [0.60, 1.20] sec
J: 2.2 MW, [0.8, 1.10] sec
Result: not a better target
D: ran 5 faults
E: ran 9 faults
J: ran 6 faults
next: USN recalling 1080422030 with 5.2 T and Ip=1 MA

Apr 23 2008 02:23:15:210PM 1080423016 Steve Wukitch dud - no gas

Apr 23 2008 02:57:51:860PM 1080423017 Steve Wukitch 017 Bt=5.2 T,Ip= 1 MA, nl04=0.7e20 /m^2, USN
D: 1 MW, [0.60, 1.20] sec
E: 1.6 MW, [0.60, 1.20] sec
J: 2.2 MW, [0.8, 1.10] sec
Result: better target (perhaps best of the day)
D: ran
E: ran
J: ran
note: some electron heating from J
next: raise J power to 2.5 MW and D power to 1.2 MW

Apr 23 2008 03:12:05:733PM 1080423018 Steve Wukitch 018 Bt=5.2 T,Ip= 1 MA, nl04=0.7e20 /m^2, USN
D: 1.2 MW, [0.60, 1.20] sec
E: 1.6 MW, [0.60, 1.20] sec
J: 2.2 MW, [0.8, 1.10] sec
Result: better yet (trophy so far)
D: ran
E: ran
J: ran
note: cleaner indication of electron heating from J
profile cannot be had from the turnoff - will need to modulate
next: raise J power to 3 MW

Apr 23 2008 03:44:08:147PM 1080423019 Steve Wukitch 019 Bt=5.2 T,Ip= 1 MA, nl04=0.7e20 /m^2, USN
D: 1.2 MW, [0.60, 1.20] sec
E: 1.6 MW, [0.60, 1.20] sec
J: 3 MW, [0.8, 1.10] sec
Result: overloaded J3 transmitter
D: ran
E: ran
J: ran - short
next: lower J power to 2.5 MW and phasing to 90 deg

Apr 23 2008 03:44:31:227PM 1080423020 Steve Wukitch early disruption

Apr 23 2008 03:56:28:343PM 1080423021 Steve Wukitch 021 Bt=5.2 T,Ip= 1 MA, nl04=0.7e20 /m^2, USN
D: 1.2 MW, [0.60, 1.20] sec
E: 1.6 MW, [0.60, 1.20] sec
J: 2.5 MW, 90deg phasing, [0.8, 1.10] sec
Result: H-mode confuses things
D: ran
E: ran
J: ran
next: repeat

Apr 23 2008 03:57:44:487PM 1080423022 Steve Wukitch 022 Bt=5.2 T,Ip= 1 MA, nl04=0.8e20 /m^2, USN
D: 1.2 MW, [0.60, 1.20] sec
E: 1.6 MW, [0.60, 1.20] sec
J: 2.5 MW, 90deg phasing, [0.8, 1.10] sec
Result: H-mode confuses things
D: ran
E: ran
J: ran
next: lower target density to 0.7

Apr 23 2008 04:06:50:507PM 1080423023 Steve Wukitch 023 Bt=5.2 T,Ip= 1 MA, nl04=0.8e20 /m^2, USN
D: 1.2 MW, [0.60, 1.20] sec
E: 1.6 MW, [0.60, 1.20] sec
J: 2.5 MW, 90deg phasing, [0.8, 1.10] sec
Result: rf cooling
D: ran
E: ran
J: ran
next: 180deg phase

Apr 23 2008 04:21:26:097PM 1080423024 Steve Wukitch 024 Bt=5.2 T,Ip= 1 MA, nl04=0.8e20 /m^2, USN
D: 1.2 MW, [0.60, 1.20] sec
E: 1.6 MW, [0.60, 1.20] sec
J: 2.5 MW, 180deg phasing, [0.8, 1.10] sec
Result: FW heating returned
D: ran
E: ran
J: ran
next: 270deg phase

Apr 23 2008 04:38:02:767PM 1080423025 Steve Wukitch 025 Bt=5.2 T,Ip= 1 MA, nl04=0.8e20 /m^2, USN
D: 1.2 MW, [0.70, 1.20] sec
E: 1.6 MW, [0.70, 1.20] sec
J: 2.5 MW, 270deg phasing, [0.8, 1.10] sec
Result: H-mode mucks the comparison
D: ran
E: ran
J: ran briefly
next: lower target density

Apr 23 2008 04:43:55:300PM 1080423026 Steve Wukitch 026 Bt=5.2 T,Ip= 1 MA, nl04=0.8e20 /m^2, USN
D: 1.2 MW, [0.70, 1.20] sec
E: 1.6 MW, [0.70, 1.20] sec
J: 2.5 MW, 270deg phasing, [0.8, 1.10] sec
Result: H-mode mucks the comparison
D: ran
E: ran
J: oeverloaded again
next: lower D+E power by 0.7 MW

Apr 23 2008 04:59:18:767PM 1080423027 Steve Wukitch 027 Bt=5.2 T,Ip= 1 MA, nl04=0.7e20 /m^2, USN
D: 1. MW, [0.70, 1.20] sec
E: 1.1 MW, [0.70, 1.20] sec
J: 2.5 MW, 180deg phasing, [0.8, 1.10] sec
Result: little or no heating, Te at top of ST is ~3.6 keV
D: ran
E: ran
J: ran
next: raise D+E power by 0.35 MW

Apr 23 2008 05:12:41:010PM 1080423029 Steve Wukitch 029 Bt=5.2 T,Ip= 1 MA, nl04=0.7e20 /m^2, USN
D: 1. MW, [0.70, 1.20] sec
E: 1.1 MW, [0.70, 1.20] sec
J: 2.5 MW, 270deg phasing, [0.8, 1.10] sec
Result: weak heating at best, Te at top of ST is ~4.4 keV
D: ran
E: ran
J: ran 1 fault

Physics Operator Comments

Apr 23 2008 09:00:21:997AM Ian Hutchinson Load from 1080125025.

This shot has 39ms fill puff. Consistent with cryopump on.

50 ms Argon puff on this shot. Turned off. PG1.
Gas is currently only Btop PG4 and Bmain PG3(6 and 42 psi)
PG2 is He3 but disabled.

This shot has rather less of a zcur swing than some other shots that day.
My understanding is that we want to go close to double null. Therefore:

Increase the zcur upward swing to make it go to 0 at 1.1s.
Sweep starts at -.014 at .75s.

Apr 23 2008 09:11:59:693AM Ian Hutchinson Cryopump will not be ready for first shot, so lower fill puff to 16ms.

Apr 23 2008 09:24:48:580AM 1080423001 Ian Hutchinson Plasma to rampdown. No RF. Plasma went marginally upper null.

Lower nl04 demand to 6 from 7e19
Cryopump now nearly cold. Increase fill puff to 40ms.

Apr 23 2008 09:46:23:703AM 1080423002 Ian Hutchinson Plasma. Disrupts at 1.27s. Many injections from the RF. Eventually kill it.

Put fill puff to .2s and reduce it to 30ms. This is to try to make the fill
level less sensitive to the presence or absence of cryopumping.

Apr 23 2008 10:03:14:543AM 1080423002 Ian Hutchinson Plasma. Disrupts at 1.27s. Many injections from the RF. Eventually kill it.

Put fill puff to .2s and reduce it to 30ms. This is to try to make the fill
level less sensitive to the presence or absence of cryopumping.

Apr 23 2008 10:03:10:013AM 1080423003 Ian Hutchinson Plasma to 1.29s. Disrupted by big injection. RF improving condition.
H-mode achieved and sustained into the upper-null phase. RF heating not great.
Fill puff worked fine.

Apr 23 2008 10:24:50:450AM 1080423004 Ian Hutchinson Plasma disrupts early. Caused by hollow Te profile and early Mo radiation
from an apparent injection at 108ms.

Increase PG3 V during the 30-90ms period. Attempt to prevent early radiation
problem.

Apr 23 2008 10:59:03:010AM 1080423005 Ian Hutchinson Plasma. Disrupts as the result of a VDE starting at 0.5s.
Actually I made the gas puff changes in the wrong segment. So it did nothing.

Program EF4 to +1000A at .5s. For some reason it was zero.
Really increase the gas puff in segment 1 around .07s.

Apr 23 2008 11:09:14:767AM 1080423006 Ian Hutchinson Very similar VDE to shot 5. We can't see why this should be happening.

Reload shot 3. [No changes]

Apr 23 2008 11:21:34:777AM 1080423007 Ian Hutchinson Plasma to ramp-down. OH2-L appears different. We suspect that it was misbehaving
for the previous two shots in a subtle way that we don't understand.
In the prior two shots the OH2 appears to follow demand but the demand is
exactly zero but with some perturbations. On this shot it looks sensible
again. In other words, M-Out appears to be incorrect in a subtle way.

Enhance gas puff in segment one.

Apr 23 2008 11:34:24:787AM 1080423007 Ian Hutchinson Plasma to ramp-down. OH2-L appears different. We suspect that it was misbehaving
for the previous two shots in a subtle way that we don't understand.
In the prior two shots the OH2 appears to follow demand but the demand is
exactly zero but with some perturbations. On this shot it looks sensible
again. In other words, M-Out appears to be incorrect in a subtle way.

Enhance gas puff in segment one.

Apr 23 2008 11:34:18:693AM 1080423008 Ian Hutchinson Fizzle with a big bounce.

Rcur offset to 1100 from 1000.

Apr 23 2008 11:54:56:397AM 1080423009 Ian Hutchinson Plasma to rampdown. Runaways from initiation. Looks like the cryopump
was outgassing.

Lower TF current to 143kA from 150.

Apr 23 2008 12:07:26:230PM 1080423010 Ian Hutchinson Plasma to rampdown.

Increase fill puff to 33ms. Ip to 1MA.
Further enhance seg 1 puff.

Apr 23 2008 12:13:41:753PM 1080423011 Ian Hutchinson Plasma to rampdown.

Apr 23 2008 12:37:05:770PM 1080423012 Ian Hutchinson Plasma to rampdown.

Apr 23 2008 12:50:53:670PM 1080423013 Ian Hutchinson Plasma to rampdown.

TF to 137kA. IC-EF4 made positive at .5s to try to prevent its reversion.
Ip to 1.2MA.

Apr 23 2008 02:04:03:477PM 1080423014 Ian Hutchinson Plasma disrupts at 1.21s

There is an oscillation that for high currents overpushes the chopper.
It has been there for the whole day, but only now it gets us.
Raise the fast zcur P from 4 to 5 to try to suppress that oscillation.
Raise TF to 143kA.

Apr 23 2008 02:11:29:700PM 1080423015 Ian Hutchinson Plasma disrupts at 1s. Vertical oscillation is changed in frequency.
Seems to indicate that the problem is arising in the whole control loop
not just as power supply noise.

Load segment 3 from 1080422030.
Set to 1 MA. Set TF to 143kA.

Apr 23 2008 02:47:03:070PM 1080423016 Ian Hutchinson Dud. No gas. PLC fault.

Apr 23 2008 03:00:53:427PM 1080423017 Ian Hutchinson Plasma to rampdown. Very low density emerges from this programming.

Increase nl04 at end of shot. Maybe didn't load.

Apr 23 2008 03:26:11:163PM 1080423018 Ian Hutchinson Disrupts at 1.27s. Density drops.

Load changes.

Apr 23 2008 03:26:21:023PM 1080423019 Ian Hutchinson Plasma to rampdown.

Apr 23 2008 03:51:47:090PM 1080423020 Ian Hutchinson Plasma disrupts at .36s caused by big injection.

Increase gas puff PG3 at 50ms.

Apr 23 2008 03:51:58:920PM 1080423021 Ian Hutchinson Plasma to rampdown.

Apr 23 2008 04:03:22:820PM 1080423022 Ian Hutchinson Plasma disrupts at 1.1s caused by big radiation event.

Apr 23 2008 04:18:24:250PM 1080423023 Ian Hutchinson Plasma to rampdown.

Tweak later current-ramp to try to avoid excessive pause.

Apr 23 2008 04:28:22:463PM 1080423024 Ian Hutchinson Plasma to rampdown.

Apr 23 2008 04:40:37:207PM 1080423025 Ian Hutchinson Plasma to rampdown.

Lower nl04 to 5.8e19 to try to prevent H-modes.

Apr 23 2008 04:54:59:107PM 1080423026 Ian Hutchinson Plasma. Disrupts at 1.32s. Hit by a brick.

Apr 23 2008 05:07:12:460PM 1080423027 Ian Hutchinson Plasma to rampdown.

Apr 23 2008 05:07:23:553PM 1080423028 Ian Hutchinson Plasma to rampdown.

Engineering Operator Comments

Shot Time Type Status Comment

1 09:05:10:157AM Plasma Ok

2 09:22:50:090AM Plasma Ok

3 09:42:48:747AM Plasma Ok

4 09:58:45:777AM Plasma Bad IOC on OH1 COM fault on OH2

5 10:14:16:663AM Plasma Ok

6 10:43:42:653AM Plasma Ok

7 11:01:14:980AM Plasma Ok

8 11:18:30:633AM Plasma Ok

9 11:32:16:240AM Plasma Ok

10 11:46:29:610AM Plasma Ok

11 12:02:47:113PM Plasma Ok

12 12:18:58:053PM Plasma Ok

13 12:33:08:250PM Plasma Ok

14 12:47:16:027PM Plasma Ok

15 01:53:02:047PM Plasma Ok

16 02:11:27:640PM Plasma Ok

17 02:43:28:693PM Plasma Ok

18 02:58:01:377PM Plasma Ok

19 03:10:28:433PM Plasma Ok

20 03:22:54:710PM Plasma Ok

21 03:35:24:623PM Plasma Ok

22 03:47:52:197PM Plasma Ok

23 04:00:56:880PM Plasma Ok

24 04:13:20:060PM Plasma Ok

25 04:25:45:070PM Plasma Ok

26 04:38:12:157PM Plasma Ok

27 04:50:44:167PM Plasma Ok

28 05:05:13:350PM Plasma Ok

System Availability

Apr 23 2008 09:05:02:250AM

System Available Comment Availability
Changed Owner Description Who Can
Change
Active MHD yes Fully operational Mar 28 2007 09:19PM (sears) Joe Snipes Active MHD Antenna sears,snipes
BES yes vertical array of six views at R ~ 87.3 cm, radial array of three views out to R ~ 89 cm, both at outboard midplane. Three discrete fiber views of beam at R ~ 70.0, 76.5 and 82.5 cm. Feb 06 2007 10:00AM (bravenec) Ron Bravenec Beam Emission Spectroscopy bravenec,rowan
Bolometers yes Diode 2pi working fine, foil 2pi being low-pass filtered to remove noise. Outboard miidplane AXUV has a grounded channel which is disrupting the whole array OFFLINE for now. Midplane foils working fine, but need to fill tree with calibrations. 2D AXUV arrays are being digitized but need further debugging and calibration. Mar 14 2008 11:09AM (mlreinke) Matt Reinke Bolometers hutch,mlreinke
Boronization no First Boronization 5/9/07 Bottle has been removed from the cell Sep 14 2007 12:42PM (dekow) Jim Irby Boronization dekow,irby
CNPA yes Single channel CNPA available as of 12/1707 Dec 17 2007 05:48PM (parker) Ron Parker Compact Neutral Analyzer parker
Cryopump - Upper Divertor yes Cryopump is operational Dec 11 2007 10:13AM (labombard) Brian LaBombard Upper Divertor Cryopump irby,labombard
CXRS yes The pedestal toroidal array was installed, spatially and absolutely calibrated. There are 10 chords intersect the beam at the major_R_range=[74.2:86.3]cm. Spatial resolution: 1.2 cm. The F-top poloidal array was installed and spatially calibrated. There are 19 chords intersect the beam at the major_R_range=[67.8:91.0]cm. Spatial resolution: 1.22 cm. Nov 27 2007 10:21AM (bespam) Bill Rowan Charge Exchange Spectroscopy bespam,blip,rachmcd,rowan
D Alpha yes \ha2_bright and \SPECTROSCOPY::TOP.VUV.VIS_SIGNALS:MCP_VIS_SIG1 are available Nov 26 2007 04:23PM (terry) Jim Terry Balmer Alpha Monitor irby,terry,wolfe
Dalsa yes optics repaired, camera re-installed, and view has been re-calibrated Nov 27 2007 09:54AM (marmar) Earl Marmar Visible Bremsstrahlung marmar
Disruption Mitigation no Nov 20 2007 10:47PM (granetz) Robert Granetz Gas Jet granetz,whyte
Divertor IR no Mar 06 2007 10:50AM Glen Wurden Divertor IR Digital Video gwurden,terry
Divertor IR Spectroscopy no Mar 06 2007 10:51AM Glen Wurden Divertor IR Spectroscopy gwurden,terry
DNB no Nov 20 2007 10:47PM (granetz) Robert Granetz Diagnostic Neutral Beam beals,granetz
FRC-ECE yes 16 Channels now working - low freq. side - outer Rmids Feb 19 2008 09:56AM (phillips) Perry Phillips Heterodyne ECE-32 channels phillips
G-Side Ratiomatic yes Gauge is operational and calibrated against G-side MKS on shot#1071127002 Nov 27 2007 01:25PM (labombard) Brian LaBombard G-side ratiomatic ionization gauge labombard,toland
GPC yes All 9 channels operational as of new year. Jan 03 2008 09:31AM (hubbard) Amanda Hubbard ECE Polychromater hubbard,schmidt
GPC2 yes Most channels operational. Jan 02 2008 12:22PM (hubbard) Amanda Hubbard ECE Polychromater hubbard,schmidt
GPI no Neither the Xpt-view nor the midplane-view camera is operational. Nov 26 2007 04:25PM (terry) Jim Terry Gas Puff Imaging terry,zweben
H/D yes Should be operational for the FY08 campaign Nov 27 2007 09:54AM (marmar) Earl Marmar H/D Ratio marmar
Hirex Jr yes Mar 06 2007 08:59AM (rice) John Rice High Resolution X-Ray ince,rice
Hirex Sr no Be Window has a leak and so the gate valve is closed Nov 23 2007 12:50PM (ince) John Rice High Resolution X-Ray ince,rice
HXR yes Something might be wrong with channel 26; all others working fine. Mar 23 2007 10:43AM (schmidt) Ron Parker Hard X-Ray Array parker,schmidt
ICRF D-Antenna yes available (quarter-wave transformer for pre-matching) Dec 11 2007 09:01AM (ylin) Steve Wukitch D-port antenna wukitch,ylin
ICRF E-Antenna yes available (with FFT for automatical matching) Dec 11 2007 09:01AM (ylin) Steve Wukitch E-port antenna wukitch,ylin
ICRF J-Antenna yes normally in [0,pi,pi,0] phase for heating. current drive phase available if requested. Dec 11 2007 09:03AM (ylin) Steve Wukitch J-port antenna wukitch,ylin
Lower Hybrid yes Body I Fault Circuits Repaired and tested. High power tests completed Dec 05 2007 06:40PM (dterry) Ron Parker Lower Hybrid dterry,parker
LPI yes 1/9/08 Jan 09 2008 03:23PM (bose) Earl Marmar Lithium Pellet Injector bose,marmar
Ly-alpha yes Midplane working fine, emissivity profiles being stored in tree, but still need to apply in-vessel calibrations to data. WB1-LY being digitized, but not processed in tree. Dec 09 2007 06:53PM (mlreinke) Matt Reinke Lyman alpha cameras labombard,mlreinke
McPherson no Problems with detector. No quantitative line brightnesses possible. Qualitative tasks like impurity identification possible. Feb 15 2008 02:07PM (mlreinke) Jim Terry VUV Spectrometer mlreinke,terry
Michelson no Dewar warm. Apr 23 2008 09:04AM (hubbard) Amanda Hubbard ECE Te Profiles hubbard,schmidt
MKS yes E-Top, E-Bottom, F-top (cryo), G-side, and B-bottom are operational. F-top gauge has a 'sniffer tube' to measure pressures in cryopump gas box. Mar 20 2007 06:42PM (g) Brian LaBombard Baratron pressure gauges labombard
MLP no Initial tests on the A-port scanning probe went well. We need to take care of some control glitches that caused some component failures. May 30 2007 08:01PM (labombard) Brian LaBombard Mirror Langmuir Probe Electronics System labombard
MSE no We are basically awaiting the DNB & its new aperture. MSE itself is OK. Feb 21 2008 08:51AM (jinseok) Steve Scott Motional Stark Effect jinseok,sscott
Neutrons yes Voltage is on for the He3 bank. Voltage will be turned on for the global system at the first plasma attempts. Nov 26 2007 08:31AM (fiore) Catherine Fiore Neutron Detectors fiore
Neuts and Hards yes calibration unchanged from 2007 campaign Dec 04 2007 08:56PM (irby) Jim Irby X-Ray/Neutron Detector at K-Hor irby
NINJA yes All capillaries displayed by the NINJA_CONTROL GUI have been tested. Nov 26 2007 04:26PM (terry) Brian LaBombard NINJA gas puff labombard,terry
PCI yes working Feb 29 2008 07:00PM (lianglin) Miklos Porkolab Phase Contrast Imaging edlund,lianglin,ntsujii,porkolab
Penning Gauges yes All gauges except B_DivL are operating Nov 27 2007 01:31PM (labombard) Brian LaBombard Penning Ionization Gauges labombard
Plasma TV yes WIDE1, WIDE2 (chan 33), DANT, JANT and DIV are operational. Nov 26 2007 04:27PM (terry) Jim Terry Video of plasma via several cameras dekow,irby,terry,wolfe
Polarimeter no Safe for Machine Entry Sep 14 2007 12:17PM (irby) Jim Irby C-Mod Polarimeter irby
Probe Array - ISD yes Operational Nov 27 2007 01:40PM (labombard) Brian Labombard Inner Lower Divertor Probe Array labombard
Probe Array - LH yes Operational Nov 27 2007 01:40PM (labombard) Brian LaBombard Lower Hybrid Probe Array labombard
Probe Array - OSD yes Operational Nov 27 2007 01:41PM (labombard) Brian LaBombard Outer Lower Divertor Probe Array labombard
Probe Array - UDIV yes Operational Nov 27 2007 01:41PM (labombard) Brian LaBombard Upper Divertor Probe Array labombard
Reflectometer yes System is fully connected except for the 75GHz channel. System was connected on 1080422. Apr 22 2008 08:26AM (dominguez) Earl Marmar Reflectometer dominguez,marmar
Scanning Probe - ASP yes Operational, but needs to be checked with plasma. Nov 27 2007 01:45PM (labombard) Brian LaBombard A-Port Scanning Probe labombard
Scanning Probe - FSP yes FSP is operational Dec 11 2007 10:13AM (labombard) Brian LaBombard F-Port Scanning Probe labombard
Scanning Probe - WASP yes A- and K-port WASP electrodes have been replaced/tested. Nov 27 2007 01:44PM (labombard) Brian LaBombard Inner Wall Scanning Probe labombard,nsmick
TCI yes CO2 Laser is on --- initial alignment complete Nov 16 2007 01:23PM (irby) Jim Irby Two-Color Interferometer irby,murray
TS - Core yes One laser operational, 12 spatial channels Apr 11 2008 10:36AM (jwhughes) Jerry Hughes Core Thomson scattering jwhughes,yma
TS - Edge yes System is working with 3 out of 4 spectral channels and should be believable for Te>50eV, ne>3e19. Density is calibrated from both Raman scattering in D2 (3/2/08) and from edge ECE cutoffs in high-density H-modes (1080228014). Apr 11 2008 10:36AM (jwhughes) Jerry Hughes Millimeter resolution edge Thomson scattering jwhughes,yma
Vispec no 350 and 670 nm, 4 spatial channels Nov 28 2007 09:58AM (agraf) Alex Graf Visible Spectrometer agraf
XTOMO yes system operational, but channels have been dying...stay tuned. Mar 14 2008 11:10AM (mlreinke) Bob Granetz X-Ray Tomography granetz,mlreinke

Session Leader Comments
Apr 23 2008 09:26:42:343AM	1080423001	Steve Wukitch	001 Bt=5.4 T,Ip= 0.8 MA, nl04=0.9e20 /m^2, LSN, gap 1.0 cm. D: 1.2 MW, [0.70, 1.30] sec E: 1.2 MW, [0.70, 1.30] sec J: 2.2 MW, [0.80, 1.30] sec Result: density was too high D: max faults E: max faults J: max faults Next: lower target density aim for better RF power
Apr 23 2008 09:52:25:287AM	1080423002	Steve Wukitch	002 Bt=5.4 T,Ip= 0.8 MA, nl04=0.9e20 /m^2, LSN, gap 1.0 cm. D: 1.2 MW, [0.70, 1.30] sec E: 1.2 MW, [0.70, 1.30] sec J: 2.2 MW, [0.80, 1.30] sec Result: D: max faults E: max faults, but better J: max faults (improved at end of pulse) Note: target density is better lots of density with RF cell access to address camera issue next: adjust J start time to 1 sec
Apr 23 2008 10:01:50:327AM	1080423003	Steve Wukitch	003 Bt=5.4 T,Ip= 0.8 MA, nl04=0.7e20 /m^2, LSN, gap 1.0 cm. D: 1.2 MW, [0.70, 1.30] sec E: 1.2 MW, [0.70, 1.30] sec J: 2.2 MW, [1., 1.30] sec Result: D: ran 2 faults E: ran 5 faults J: ran 7 faults (improving towards end of pulse) Note: temperature too low at start of J antenna for any fast wave damping still evolving density with D+E but cryopump is pumping if this H/D is too be believed, H is too low next: repeat, monitor density evolution and H fraction
Apr 23 2008 10:02:05:637AM	1080423004	Steve Wukitch	early disruption
Apr 23 2008 11:10:04:987AM	1080423005	Steve Wukitch	early disruption
Apr 23 2008 11:10:15:860AM	1080423006	Steve Wukitch	early disruption reload 003
Apr 23 2008 11:19:51:807AM	1080423007	Steve Wukitch	007 Bt=5.4 T,Ip= 0.8 MA, nl04=0.6e20 /m^2, LSN to USN D: 1.2 MW, [0.70, 1.30] sec E: 1.2 MW, [0.70, 1.30] sec J: 2.2 MW, [1., 1.30] sec Result: D: max faults E: ran 1 fault J: ran 10 faults Note: temperature still too low at start of J antenna but interesting transition at 1.18 s and another at 1.23 s still evolving density with D+E but cryopump is pumping H/D indicates 4% next: move D+E start to 0.6 s and raise power to 2.5 MW
Apr 23 2008 11:25:45:357AM	1080423008	Steve Wukitch	fizzle
Apr 23 2008 12:04:33:900PM	1080423009	Steve Wukitch	009 Bt=5.4 T,Ip= 0.8 MA, nl04=0.6e20 /m^2, LSN to USN D: 1.2 MW, [0.70, 1.30] sec E: 1.5 MW, [0.70, 1.30] sec J: 2.2 MW, [1., 1.30] sec Result: D: ran 1 fault E: ran 2 faults J: ran 3 faults Note: better target but no real significant heating next: lower B to 5.2 T
Apr 23 2008 11:58:05:940AM	1080423010	Steve Wukitch	010 Bt=5.2 T,Ip= 0.8 MA, nl04=0.6e20 /m^2, LSN to USN D: 1.2 MW, [0.60, 1.20] sec E: 1.5 MW, [0.70, 1.20] sec J: 2.5 MW, [0.8, 1.20] sec Result: D: ran E: ran J: ran overload Note: decent target (central Te dropped from 3.5 to 3 at top of sawteeth and no real significant heating observed with J next: raise plasma current to 1 MA
Apr 23 2008 12:22:50:773PM	1080423011	Steve Wukitch	011 Bt=5.2 T,Ip= 1 MA, nl04=0.8e20 /m^2, LSN to USN D: 1.2 MW, [0.60, 1.20] sec E: 1.5 MW, [0.70, 1.20] sec J: 2.2 MW, [0.8, 1.20] sec Result: D: screen overload E: max faults J: max faults Note: good target (central Te to 3.8 at top of sawteeth) next: repeat with better RF
Apr 23 2008 12:28:41:217PM	1080423012	Steve Wukitch	012 Bt=5.2 T,Ip= 1 MA, nl04=0.8e20 /m^2, LSN to USN D: 1.2 MW, [0.60, 1.20] sec E: 1.5 MW, [0.60, 1.20] sec J: 2.2 MW, [0.8, 1.10] sec Result: D: ran briefly then xbar and screen overload E: ran multiple faults J: ran with faults next: repeat with better RF - back off D
Apr 23 2008 12:38:04:240PM	1080423013	Steve Wukitch	013 Bt=5.2 T,Ip= 1 MA, nl04=0.8e20 /m^2, LSN to USN D: 1 MW, [0.60, 1.20] sec E: 1.5 MW, [0.60, 1.20] sec J: 2.2 MW, [0.8, 1.10] sec Result: D: ran 1 fault E: did not run - silent fault from FFT J: ran 2 faults next: this time with E antenna
Apr 23 2008 01:26:53:823PM	1080423014	Steve Wukitch	014 Bt=5 T,Ip= 1.2 MA, nl04=0.8e20 /m^2, LSN to USN D: 1 MW, [0.60, 1.20] sec E: 1.6 MW, [0.60, 1.20] sec J: 2.2 MW, [0.8, 1.10] sec Result: not a better target D: ran 7 faults E: ran 9 faults J: ran next: return to 5.2 T
Apr 23 2008 02:23:01:163PM	1080423015	Steve Wukitch	015 Bt=5.2 T,Ip= 1.2 MA, nl04=0.7e20 /m^2, LSN to USN D: 1 MW, [0.60, 1.20] sec E: 1.6 MW, [0.60, 1.20] sec J: 2.2 MW, [0.8, 1.10] sec Result: not a better target D: ran 5 faults E: ran 9 faults J: ran 6 faults next: USN recalling 1080422030 with 5.2 T and Ip=1 MA
Apr 23 2008 02:23:15:210PM	1080423016	Steve Wukitch	dud - no gas
Apr 23 2008 02:57:51:860PM	1080423017	Steve Wukitch	017 Bt=5.2 T,Ip= 1 MA, nl04=0.7e20 /m^2, USN D: 1 MW, [0.60, 1.20] sec E: 1.6 MW, [0.60, 1.20] sec J: 2.2 MW, [0.8, 1.10] sec Result: better target (perhaps best of the day) D: ran E: ran J: ran note: some electron heating from J next: raise J power to 2.5 MW and D power to 1.2 MW
Apr 23 2008 03:12:05:733PM	1080423018	Steve Wukitch	018 Bt=5.2 T,Ip= 1 MA, nl04=0.7e20 /m^2, USN D: 1.2 MW, [0.60, 1.20] sec E: 1.6 MW, [0.60, 1.20] sec J: 2.2 MW, [0.8, 1.10] sec Result: better yet (trophy so far) D: ran E: ran J: ran note: cleaner indication of electron heating from J profile cannot be had from the turnoff - will need to modulate next: raise J power to 3 MW
Apr 23 2008 03:44:08:147PM	1080423019	Steve Wukitch	019 Bt=5.2 T,Ip= 1 MA, nl04=0.7e20 /m^2, USN D: 1.2 MW, [0.60, 1.20] sec E: 1.6 MW, [0.60, 1.20] sec J: 3 MW, [0.8, 1.10] sec Result: overloaded J3 transmitter D: ran E: ran J: ran - short next: lower J power to 2.5 MW and phasing to 90 deg
Apr 23 2008 03:44:31:227PM	1080423020	Steve Wukitch	early disruption
Apr 23 2008 03:56:28:343PM	1080423021	Steve Wukitch	021 Bt=5.2 T,Ip= 1 MA, nl04=0.7e20 /m^2, USN D: 1.2 MW, [0.60, 1.20] sec E: 1.6 MW, [0.60, 1.20] sec J: 2.5 MW, 90deg phasing, [0.8, 1.10] sec Result: H-mode confuses things D: ran E: ran J: ran next: repeat
Apr 23 2008 03:57:44:487PM	1080423022	Steve Wukitch	022 Bt=5.2 T,Ip= 1 MA, nl04=0.8e20 /m^2, USN D: 1.2 MW, [0.60, 1.20] sec E: 1.6 MW, [0.60, 1.20] sec J: 2.5 MW, 90deg phasing, [0.8, 1.10] sec Result: H-mode confuses things D: ran E: ran J: ran next: lower target density to 0.7
Apr 23 2008 04:06:50:507PM	1080423023	Steve Wukitch	023 Bt=5.2 T,Ip= 1 MA, nl04=0.8e20 /m^2, USN D: 1.2 MW, [0.60, 1.20] sec E: 1.6 MW, [0.60, 1.20] sec J: 2.5 MW, 90deg phasing, [0.8, 1.10] sec Result: rf cooling D: ran E: ran J: ran next: 180deg phase
Apr 23 2008 04:21:26:097PM	1080423024	Steve Wukitch	024 Bt=5.2 T,Ip= 1 MA, nl04=0.8e20 /m^2, USN D: 1.2 MW, [0.60, 1.20] sec E: 1.6 MW, [0.60, 1.20] sec J: 2.5 MW, 180deg phasing, [0.8, 1.10] sec Result: FW heating returned D: ran E: ran J: ran next: 270deg phase
Apr 23 2008 04:38:02:767PM	1080423025	Steve Wukitch	025 Bt=5.2 T,Ip= 1 MA, nl04=0.8e20 /m^2, USN D: 1.2 MW, [0.70, 1.20] sec E: 1.6 MW, [0.70, 1.20] sec J: 2.5 MW, 270deg phasing, [0.8, 1.10] sec Result: H-mode mucks the comparison D: ran E: ran J: ran briefly next: lower target density
Apr 23 2008 04:43:55:300PM	1080423026	Steve Wukitch	026 Bt=5.2 T,Ip= 1 MA, nl04=0.8e20 /m^2, USN D: 1.2 MW, [0.70, 1.20] sec E: 1.6 MW, [0.70, 1.20] sec J: 2.5 MW, 270deg phasing, [0.8, 1.10] sec Result: H-mode mucks the comparison D: ran E: ran J: oeverloaded again next: lower D+E power by 0.7 MW
Apr 23 2008 04:59:18:767PM	1080423027	Steve Wukitch	027 Bt=5.2 T,Ip= 1 MA, nl04=0.7e20 /m^2, USN D: 1. MW, [0.70, 1.20] sec E: 1.1 MW, [0.70, 1.20] sec J: 2.5 MW, 180deg phasing, [0.8, 1.10] sec Result: little or no heating, Te at top of ST is ~3.6 keV D: ran E: ran J: ran next: raise D+E power by 0.35 MW
Apr 23 2008 05:12:41:010PM	1080423029	Steve Wukitch	029 Bt=5.2 T,Ip= 1 MA, nl04=0.7e20 /m^2, USN D: 1. MW, [0.70, 1.20] sec E: 1.1 MW, [0.70, 1.20] sec J: 2.5 MW, 270deg phasing, [0.8, 1.10] sec Result: weak heating at best, Te at top of ST is ~4.4 keV D: ran E: ran J: ran 1 fault

Physics Operator Comments
Apr 23 2008 09:00:21:997AM		Ian Hutchinson	Load from 1080125025. This shot has 39ms fill puff. Consistent with cryopump on. 50 ms Argon puff on this shot. Turned off. PG1. Gas is currently only Btop PG4 and Bmain PG3(6 and 42 psi) PG2 is He3 but disabled. This shot has rather less of a zcur swing than some other shots that day. My understanding is that we want to go close to double null. Therefore: Increase the zcur upward swing to make it go to 0 at 1.1s. Sweep starts at -.014 at .75s.
Apr 23 2008 09:11:59:693AM		Ian Hutchinson	Cryopump will not be ready for first shot, so lower fill puff to 16ms.
Apr 23 2008 09:24:48:580AM	1080423001	Ian Hutchinson	Plasma to rampdown. No RF. Plasma went marginally upper null. Lower nl04 demand to 6 from 7e19 Cryopump now nearly cold. Increase fill puff to 40ms.
Apr 23 2008 09:46:23:703AM	1080423002	Ian Hutchinson	Plasma. Disrupts at 1.27s. Many injections from the RF. Eventually kill it. Put fill puff to .2s and reduce it to 30ms. This is to try to make the fill level less sensitive to the presence or absence of cryopumping.
Apr 23 2008 10:03:14:543AM	1080423002	Ian Hutchinson	Plasma. Disrupts at 1.27s. Many injections from the RF. Eventually kill it. Put fill puff to .2s and reduce it to 30ms. This is to try to make the fill level less sensitive to the presence or absence of cryopumping.
Apr 23 2008 10:03:10:013AM	1080423003	Ian Hutchinson	Plasma to 1.29s. Disrupted by big injection. RF improving condition. H-mode achieved and sustained into the upper-null phase. RF heating not great. Fill puff worked fine.
Apr 23 2008 10:24:50:450AM	1080423004	Ian Hutchinson	Plasma disrupts early. Caused by hollow Te profile and early Mo radiation from an apparent injection at 108ms. Increase PG3 V during the 30-90ms period. Attempt to prevent early radiation problem.
Apr 23 2008 10:59:03:010AM	1080423005	Ian Hutchinson	Plasma. Disrupts as the result of a VDE starting at 0.5s. Actually I made the gas puff changes in the wrong segment. So it did nothing. Program EF4 to +1000A at .5s. For some reason it was zero. Really increase the gas puff in segment 1 around .07s.
Apr 23 2008 11:09:14:767AM	1080423006	Ian Hutchinson	Very similar VDE to shot 5. We can't see why this should be happening. Reload shot 3. [No changes]
Apr 23 2008 11:21:34:777AM	1080423007	Ian Hutchinson	Plasma to ramp-down. OH2-L appears different. We suspect that it was misbehaving for the previous two shots in a subtle way that we don't understand. In the prior two shots the OH2 appears to follow demand but the demand is exactly zero but with some perturbations. On this shot it looks sensible again. In other words, M-Out appears to be incorrect in a subtle way. Enhance gas puff in segment one.
Apr 23 2008 11:34:24:787AM	1080423007	Ian Hutchinson	Plasma to ramp-down. OH2-L appears different. We suspect that it was misbehaving for the previous two shots in a subtle way that we don't understand. In the prior two shots the OH2 appears to follow demand but the demand is exactly zero but with some perturbations. On this shot it looks sensible again. In other words, M-Out appears to be incorrect in a subtle way. Enhance gas puff in segment one.
Apr 23 2008 11:34:18:693AM	1080423008	Ian Hutchinson	Fizzle with a big bounce. Rcur offset to 1100 from 1000.
Apr 23 2008 11:54:56:397AM	1080423009	Ian Hutchinson	Plasma to rampdown. Runaways from initiation. Looks like the cryopump was outgassing. Lower TF current to 143kA from 150.
Apr 23 2008 12:07:26:230PM	1080423010	Ian Hutchinson	Plasma to rampdown. Increase fill puff to 33ms. Ip to 1MA. Further enhance seg 1 puff.
Apr 23 2008 12:13:41:753PM	1080423011	Ian Hutchinson	Plasma to rampdown.
Apr 23 2008 12:37:05:770PM	1080423012	Ian Hutchinson	Plasma to rampdown.
Apr 23 2008 12:50:53:670PM	1080423013	Ian Hutchinson	Plasma to rampdown. TF to 137kA. IC-EF4 made positive at .5s to try to prevent its reversion. Ip to 1.2MA.
Apr 23 2008 02:04:03:477PM	1080423014	Ian Hutchinson	Plasma disrupts at 1.21s There is an oscillation that for high currents overpushes the chopper. It has been there for the whole day, but only now it gets us. Raise the fast zcur P from 4 to 5 to try to suppress that oscillation. Raise TF to 143kA.
Apr 23 2008 02:11:29:700PM	1080423015	Ian Hutchinson	Plasma disrupts at 1s. Vertical oscillation is changed in frequency. Seems to indicate that the problem is arising in the whole control loop not just as power supply noise. Load segment 3 from 1080422030. Set to 1 MA. Set TF to 143kA.
Apr 23 2008 02:47:03:070PM	1080423016	Ian Hutchinson	Dud. No gas. PLC fault.
Apr 23 2008 03:00:53:427PM	1080423017	Ian Hutchinson	Plasma to rampdown. Very low density emerges from this programming. Increase nl04 at end of shot. Maybe didn't load.
Apr 23 2008 03:26:11:163PM	1080423018	Ian Hutchinson	Disrupts at 1.27s. Density drops. Load changes.
Apr 23 2008 03:26:21:023PM	1080423019	Ian Hutchinson	Plasma to rampdown.
Apr 23 2008 03:51:47:090PM	1080423020	Ian Hutchinson	Plasma disrupts at .36s caused by big injection. Increase gas puff PG3 at 50ms.
Apr 23 2008 03:51:58:920PM	1080423021	Ian Hutchinson	Plasma to rampdown.
Apr 23 2008 04:03:22:820PM	1080423022	Ian Hutchinson	Plasma disrupts at 1.1s caused by big radiation event.
Apr 23 2008 04:18:24:250PM	1080423023	Ian Hutchinson	Plasma to rampdown. Tweak later current-ramp to try to avoid excessive pause.
Apr 23 2008 04:28:22:463PM	1080423024	Ian Hutchinson	Plasma to rampdown.
Apr 23 2008 04:40:37:207PM	1080423025	Ian Hutchinson	Plasma to rampdown. Lower nl04 to 5.8e19 to try to prevent H-modes.
Apr 23 2008 04:54:59:107PM	1080423026	Ian Hutchinson	Plasma. Disrupts at 1.32s. Hit by a brick.
Apr 23 2008 05:07:12:460PM	1080423027	Ian Hutchinson	Plasma to rampdown.
Apr 23 2008 05:07:23:553PM	1080423028	Ian Hutchinson	Plasma to rampdown.

Engineering Operator Comments
Shot	Time	Type	Status	Comment
1	09:05:10:157AM	Plasma	Ok
2	09:22:50:090AM	Plasma	Ok
3	09:42:48:747AM	Plasma	Ok
4	09:58:45:777AM	Plasma	Bad	IOC on OH1 COM fault on OH2
5	10:14:16:663AM	Plasma	Ok
6	10:43:42:653AM	Plasma	Ok
7	11:01:14:980AM	Plasma	Ok
8	11:18:30:633AM	Plasma	Ok
9	11:32:16:240AM	Plasma	Ok
10	11:46:29:610AM	Plasma	Ok
11	12:02:47:113PM	Plasma	Ok
12	12:18:58:053PM	Plasma	Ok
13	12:33:08:250PM	Plasma	Ok
14	12:47:16:027PM	Plasma	Ok
15	01:53:02:047PM	Plasma	Ok
16	02:11:27:640PM	Plasma	Ok
17	02:43:28:693PM	Plasma	Ok
18	02:58:01:377PM	Plasma	Ok
19	03:10:28:433PM	Plasma	Ok
20	03:22:54:710PM	Plasma	Ok
21	03:35:24:623PM	Plasma	Ok
22	03:47:52:197PM	Plasma	Ok
23	04:00:56:880PM	Plasma	Ok
24	04:13:20:060PM	Plasma	Ok
25	04:25:45:070PM	Plasma	Ok
26	04:38:12:157PM	Plasma	Ok
27	04:50:44:167PM	Plasma	Ok
28	05:05:13:350PM	Plasma	Ok