Alcator C-Mod Run 1060412 Information

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Miniproposals
Miniproposal:409
Date Filed: 1/19/2005
Title:Phase Space of the Scrape-off-Layer Plasma
First Author:Brian Labombard
Session Leader:Brian Labombard (shots 1-30)
Miniproposal:429
Date Filed: 7/25/2005
Title:SOL turbulence in limited plasmas
First Author:Stewart Zweben
Session Leader:Stewart Zweben (shots 22-27)

Operators
Session leader(s):Brian Labombard,Stewart Zweben
Physics operator(s):Ian Hutchinson,Steve Wolfe,Ian Hutchinson,Ian Hutchinson
Engineering operator(s):Bill Cochran,Bill Parkin

Engineering Operator Run Comment
MP#409: SOL Phase Space (9:00 to 16:00) MP#429 Turbulence in limited dis

Session Leader Plans
Entered: Apr 11 2006 04:03:54:200PM
Author: Brian Labombard
===========================
Engineering setup for Wednesday 12 Apr 2006

MP#409: SOL Phase Space (9:00 to 16:00)
MP#429 Turbulence in limited discharges (16:00 to 17:00)

Session leader: B. Labombard
Physics operator: I. Hutchinson

Overnight ECDC in D2, and bake at 60 C.

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

Power systems as on 1060324023 (1.1 MA, 5.4 T, lower single null)

A-coil configuration: normal [+Dtop -Dbot -Jtop +Jbot] and enabled.

Gas Setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar + 2 psi Ne Hybrid DISABLED (PG1)
leave B-side upper as is Hybrid DISABLED (PG2)
fill B-main (C-side) with 40 psi D2 Hybrid enabled (PG3)
fill NINJA with 10 psi D2 Leave DISABLED

Enable the following gate valves and shutters, assuming no vacuum problems:
ECE, VUV, Z-bolo shutters

Torvac setup: Gate valves open

ICRF Setup: No RF today.

Important Diagnostics:
ASP, FSP, ISP, Xybion camera, fast H-alpha diode array, Chromex, Edge TS

===================================
Run Plan for 1060412

MP#409 "SOL Phase space studies"

Overal Goal
Map out the 'phase space' of the SOL plasma, i.e. the relationships between
the 'transport state' (profile shapes, gradients, cross-field fluxes, advection
velocities, turbulence characteristics) and theory-based 'control parameters'
(local collisionality, magnetic field strengths, parallel connection length,...)
that may determine that state.

Today's Goals
(a) Attempt to collect some high density data points at Ip=1.1 MA and Bt=5.4 tesla
(b) Move on to a density scan at Ip= 0.8 MA and Bt=4 tesla, NL04=(0.4, 0.6, 0.8,
1.0, 1.2) x10^20 m^-2. This is close to the ohmic H-mode boundary
(c) Start doing density ramp-up shots for density limit studies.

Notes
- Set integration time on Xybion to 1 ms
- Connect the following fiber views for the fast diodes
Outer SOL views 1-3,5,7,9-14,31-40 (total of 21)
Innerwall SOL views B and C
- Connect the following fiber views for the CHROMEX
Outer SOL views 18-22,24-29 (total of 11)
Innerwall SOL views A,D,E,F - otherwise known as 1,4-6
- Set timing on fastdiode digitizers to 0.1 s after the A-B limiter NINJA puff timing
Plan
Load from shot#1060324023. This shot ran on segment#2. It was a LSN discharge
with Ip=1.1 MA, Bt= 5.4 tesla, NL04 = 1.7e20. Note: segment#3 has
a USN program that we will also use.

ASP, FSP, ISP programmed to scan at 0.65, 0.85, 1.05 seconds

Shots

Reload from 1060324023 (segment#2 active)
Ip= 1.1 MA, set NL04 = 1.4
1,2 LSN, optimize probe insertion
3,4,5 Push up density in increments of 0.1

Go to segment#3 (USN, last run as shot#1060324021) set NL04=1.4
6,7 USN optimize probe insertion
8,9,10 Push up density in increments of 0.1

Change to Bt=4T, Ip= 0.8 MA and continue LSN/USN sequence
Reload 1050602008
NL04 = 0.6

NL04 = 0.4

NL04 = 0.8

NL04 = 1.0

NL04 = 1.2

Start density ramp-up shots
(a) Ip=0.8, Bt=4.0
(b) Ip=1.1, Bt=5.4

Physics Operators Plans

Session Leader Summaries
Entered: Apr 12 2006 05:19:40:500PM
Author: Brian Labombard
Run Summary for 1060412

MP#409 "SOL Phase space studies"
___________________________________________________________________________________
Overal Goal
Map out the 'phase space' of the SOL plasma, i.e. the relationships between
the 'transport state' (profile shapes, gradients, cross-field fluxes, advection
velocities, turbulence characteristics) and theory-based 'control parameters'
(local collisionality, magnetic field strengths, parallel connection length,...)
that may determine that state.

Today's Goals
(a) Attempt to collect some high density data points at Ip=1.1 MA and Bt=5.4 tesla
(b) Move on to a density scan at Ip= 0.8 MA AND Bt=4 tesla, NL04=(0.4, 0.6, 0.8,
1.0, 1.2) x10^20 m^-2. This is close to the ohmic H-mode boundary
(c) Start doing density ramp-up shots for density limit studies.
___________________________________________________________________________________
This was a somewhat successful day. We picked up some high density data points at 1.1MA
in LSN and USN (item "a" above). We skipped (b) and got some limited shots for Stewart
(MP#429). Finally, we started on doing some density ramp-up shots (c) at Ip=0.4MA
and Bt=4 tesla, but only got one good shot.
Unfortunately, we totally toasted the F-port probe on shot#12.
___________________________________________________________________________________
Quick shot log

Shots from 1060412
MP#409
High density shots in LSN for Ip=1.1MA Bt=5.4tesla
4- LSN, Ip=1.1MA, NL04=1.55 ASP(+5) could be deeper, FSP (+0) far out, ISP-good
5- LSN, Ip=1.1MA, NL04=1.75 ASP(+7) still could be deeper, FSP (+7) could be deeper, ISP-good
6- LSN, Ip=1.1MA, NL04=1.5 ASP(+9), FSP (+9), ISP-good
7- LSN, Ip=1.1MA, NL04=1.5 ASP(+9), FSP (+9), ISP-good
Disrupted on second scan - probe induced
8- LSN, Ip=1.1MA, NL04=1.5 ASP(+8) East probe shorted, FSP (+8), ISP-good
9- LSN, Ip=1.1MA, NL04=1.5 ASP(+8) East probe shorted, FSP (+8), ISP-good

High density shots in USN for Ip=1.1MA Bt=5.4tesla
10- USN, Ip=1.1MA, NL04=1.2-1.3 ASP(+8) East probe shorted, FSP (+8), ISP-good
11- Lost NL04, gassy disruption early
change to z-meter feedback
12- USN, Ip=1.1MA, NL04=1? (based on Thomson) ASP(+12) East probe shorted, FSP (+9), ISP-good
Z-meter feeback for density.
Wrong programming! Should have been an USN discharge.
ASP - may have survived disruption. East is floating (shorted to head)
FSP - Way overinserted, Becomes a limiter on the second scan and disrupts plasma.
Glowing projectiles on video.
ISP - ok
13-Early disruption
14- USN, Ip=1.1MA, NL04=1.9,1.3,1.6 (early MARFE) ASP(+5) way out, East probe shorted, FSP (+0) no scan, ISP-no scan
15- USN, Ip=1.1MA, NL04=1.3,1.6,1.7 (early MARFE) ASP(+12) East probe shorted, FSP (+0)-shorted, ISP
16- USN, Ip=1.1MA, NL04=1.2,1.5,1.65 (early MARFE) ASP(+14) Good, East probe shorted, FSP (+0), ISP
17- USN, Ip=1.1MA, NL04=1.1,1.2,1.3 ASP(+14) East probe shorted, FSP (+5), ISP
18- USN, Ip=1.1MA, NL04=1.25,1.45,1.6 ASP(+14) East probe shorted, FSP (+5), ISP
19- USN, Ip=1.1MA, NL04=1.2,1.4,1.8(based on thomson) ASP(+14) East probe shorted, FSP (+7), ISP
20- USN, Ip=1.1MA, NL04=1.3,1.7,2.0(based on thomson) ASP(+14) East probe shorted, FSP (+7), ISP
21- USN, Ip=1.1MA, NL04=1.4,1.7,2.0 ASP(+14) East probe shorted, FSP (+7), ISP

Inner limited shots for MP#429
22- Inner Limited, Ip=0.78, NL04=1.2, no probes scanning
23- Inner Limited, NL04=0.8,1.0,1.0, Ip=0.8, Bt=5.4, ASP (+30)- great I-V data. East probe is now working.
24- Inner Limited, NL04=0.9,0.9,1.1, Ip=0.8, Bt=5.4, ASP (+30)- I-V data 0.65, 0.85, 1.15s
25- fizzle
26- Inner Limited, NL04=0.8,0.9,1.0, Ip=0.8, Bt=5.4, ASP (+30)- Vf data 0.65, 0.85, 1.15s
27- Inner Limited, NL04=0.8,0.9,1.0, Ip=0.8, Bt=5.4, ASP (+30)- I-V data 0.65, 0.85, 1.15s

Back to MP#409
Start density ramp-up shots at Ip=0.4, Bt=4.0
28- LSN, NL04=0.53,0.58, Ip=0.4, Bt=4, ASP (+12)-dwell scan, FSP, ISP(22ms) 0.65, 0.85, 1.15s
Marfe leading to disruption at 0.88
29- LSN, NL04=0.53,0.58, Ip=0.4, Bt=4, ASP (+10)-dwell scan, FSP, ISP(18ms) 0.65, 0.85, 1.15s
Marfe leading to disruption at 0.84
30 LSN, NL04=0.4-0.7 Ip=0.4, Bt=4, ASP-dwell, FSP,ISP scanning at 0.65, 0.85, 1.05s
ASP in dwell mode - data looks ok
Entered: Apr 13 2006 09:28:54:863AM
Author: Stewart Zweben
Continuation of MP#429, SOL turbulence in limited plasmas
same plasma set up as 1060316018 (used for template today)
0.8 MA, 5.4 T, inner wall limited, kappa=1.2, 3.5 cm outer gap
all with GPI puff at AB limiter and PSI-5 camera data

1060412022 - good, GPI puff 4.5 T-l at 1.05 sec
1060412023 - good, GPI puff 7.9 T-l at 1.05 sec
1060412024 - good, GPI puff 7.9 T-l at 1.05 sec
1060412025 - fizzle
1060412026 - good, GPI puff 7.9 T-l at 1.05 sec
1060412027 - good, GPI puff 2.5 T-l at 1.05 sec

all has inner wall marfes except perhaps last one
most had scanning probe data

Physics Operator Summaries
Entered: Apr 12 2006 05:03:00:297PM
Author: Ian Hutchinson
Summary

A reasonably successful run after several early tests. Power supply limits were mis-set for some of the high density shots, resulting in ramp-down disruptions. But they did not seem to matter much.

No duds. Sparker was sparking on most shots. However, there was a clear evolution in the Bz ramp rate with time. It slowed a lot towards the end of the day. This did not seem to have any explanation.

Scorecard

Shot,Duration(s),Ipmax(MA),Result Shot,Duration(s),Ipmax,Result
| 01 0.000 0.001 Dud | 02 0.000 0.001 Dud |
| 03 0.000 0.001 Dud | 04 1.662 1.094 Plasma |
| 05 1.459 1.089 Plasma | 06 1.642 1.094 Plasma |
| 07 0.870 1.197 Plasma | 08 1.650 1.094 Plasma |
| 09 1.662 1.093 Plasma | 10 1.703 1.095 Plasma |
| 11 0.467 1.105 Plasma | 12 0.858 1.370 Plasma |
| 13 0.351 0.786 Plasma | 14 1.682 1.098 Plasma |
| 15 1.502 1.098 Plasma | 16 1.538 1.101 Plasma |
| 17 1.719 1.100 Plasma | 18 1.683 1.097 Plasma |
| 19 1.534 1.096 Plasma | 20 1.416 1.140 Plasma |
| 21 1.338 1.242 Plasma | 22 1.582 0.784 Plasma |
| 23 1.875 0.794 Plasma | 24 1.347 0.831 Plasma |
| 25 0.000 0.031 Fizzle | 26 1.373 0.807 Plasma |
| 27 1.947 0.801 Plasma | 28 0.873 0.537 Plasma |
| 29 0.835 0.540 Plasma | 30 1.477 0.524 Plasma |

Date 1060412: 30 shots. 26 plasmas. 1 fizzles. Tests. 0 System Error.
(Plasma = Ip gt 50.0 kA Dud = H_alpha lt 0.40 V)
Total plasma duration: 36.05 s (exceeding -100 kA)

Session Leader Comments
Apr 12 2006 09:38:25:417AM1060412004Brian LabombardShot 4 LSN, NL04=1.55, Ip=1.1 MA, Bt=5.4T, ASP,FSP,ISP scanning at 0.65, 0.85, 1.05s
ASP - could be deeper - a bit noisy
FSP - far out
ISP - ok

Next: repeat with probes adjusted
Apr 12 2006 09:58:46:400AM1060412005Brian LabombardShot 5 LSN, NL04=1.75, Ip=1.1 MA, Bt=5.4T, ASP,FSP,ISP scanning at 0.65, 0.85, 1.05s
ASP - ok, still could be deeper
FSP - ok, could be deeper
ISP - ok

Next: repeat
Apr 12 2006 10:05:48:150AM1060412006Brian LabombardShot 6 LSN, NL04=1.5, Ip=1.1 MA, Bt=5.4T, ASP,FSP,ISP scanning at 0.65, 0.85, 1.05s
ASP - great
FSP - ok
ISP - ok

Next: repeat, trying to get back to NL04 = 1.7
Apr 12 2006 10:20:03:087AM1060412007Brian LabombardShot 7 LSN, NL04=1.5, Ip=1.1 MA, Bt=5.4T, ASP,FSP,ISP scanning at 0.65, 0.85, 1.05s
ASP - overinserted, East probe overheated, disrupts on second scan
FSP - ok
ISP - ok

Next: try again with ASP pulled back
Apr 12 2006 10:31:20:073AM1060412008Brian LabombardShot 8 LSN, NL04=1.55, Ip=1.1 MA, Bt=5.4T, ASP,FSP,ISP scanning at 0.65, 0.85, 1.05s
ASP - ok, but East probe is shorted to the head now.
FSP - ok
ISP - ok

Next: repeat with argon puff for John
Apr 12 2006 10:43:39:353AM1060412009Brian LabombardShot 9 LSN, NL04=1.45, Ip=1.1 MA, Bt=5.4T, ASP,FSP,ISP scanning at 0.65, 0.85, 1.05s
ASP - ok, East is floating now (shorted to head)
FSP - ok
ISP - ok

Next: go to USN
Apr 12 2006 11:00:33:823AM1060412010Brian LabombardShot 10 LSN, NL04=1.2-1.3, Ip=1.1 MA, Bt=5.4T, ASP,FSP,ISP scanning at 0.65, 0.85, 1.05s
ASP - needs to be deeper. East is floating (shorted to head)
FSP - could be deeper
ISP - ok

Next: repeat with probes adjusted, try for NL04=1.5
Apr 12 2006 12:06:48:130PM1060412012Brian LabombardShot 12 LSN, NL04=1? (based on Thomson), Ip=1.2 MA, Bt=5.4T, ASP,FSP,ISP scanning at 0.65, 0.85, 1.05s
Z-meter feeback for density.
Wrong programming! Should have been an USN discharge.

ASP - may have survived disruption. East is floating (shorted to head)
FSP - Way overinserted, Becomes a limiter on the second scan and disrupts plasma.
Glowing projectiles on video.
ISP - ok

Next: try for the discharge we want. No probes scanning for now.
Apr 12 2006 12:20:09:897PM1060412014Brian LabombardShot 14 USN, NL04=1.9, 1.3, 1.6 (early MARFE) Ip=1.1 MA, Bt=5.4T, ASP scanning at 0.65, 0.85, 1.05s
ASP - Still working, scanning far out. East is floating (shorted to head)
FSP - not scanning
ISP - not scanning

Next: Repeat with A-port probe
Apr 12 2006 12:42:11:507PM1060412015Brian LabombardShot 15 USN, NL04=1.3 1.6,1.7 (early MARFE) Ip=1.1, Bt=5.4, ASP,FSP,ISP scanning at 0.65, 0.85, 1.05s
ASP - Could be deeper, East is floating (shorted to head)
FSP - Looks like electrodes are shorted to the head (Initially I thought they weren't)
ISP - ok

Next: Repeat with probes adjusted.
Apr 12 2006 01:08:06:193PM1060412016Brian LabombardShot 16 USN, NL04=1.2 1.5,1.6 Ip=1.1, Bt=5.4, ASP,FSP,ISP scanning at 0.65, 0.85, 1.05s
ASP - Good. East is floating (shorted to head)
FSP -
ISP - ok

Next: repeat
Apr 12 2006 01:06:02:007PM1060412017Brian LabombardShot 17 USN, NL04=1.1 1.2,1.3 Ip=1.1, Bt=5.4, ASP,FSP,ISP scanning at 0.65, 0.85, 1.05s
ASP - Good. East is floating (shorted to head)
FSP - May be working. Raw traces look different
ISP - ok

Next: go to NL04=1.8
Apr 12 2006 01:20:17:960PM1060412018Brian LabombardShot 18 USN, NL04=1.25 1.45,1.6 Ip=1.1, Bt=5.4, ASP,FSP,ISP scanning at 0.65, 0.85, 1.05s
ASP - Good. East is floating (shorted to head)
FSP -
ISP - ok

Next: try for higher density still
Apr 12 2006 01:32:08:023PM1060412019Brian LabombardShot 19 USN, NL04=1.2 1.4,1.8 (based on Thomson) Ip=1.1, Bt=5.4, ASP,FSP,ISP scanning at 0.65, 0.85, 1.05s
ASP - Good. East is floating (shorted to head)
FSP -
ISP - ok

Next: try for more density again.
Apr 12 2006 01:53:48:583PM1060412020Brian LabombardShot 20 USN, NL04=1.3 1.7,2.0 (based on Thomson) Ip=1.1, Bt=5.4, ASP,FSP,ISP scanning at 0.65, 0.85, 1.05s
ASP - Good. East is floating (shorted to head)
FSP -
ISP - ok

Next: repeat with density NL04 of about 2.0 earlier
Apr 12 2006 02:13:58:290PM1060412021Brian LabombardShot 21 USN, NL04=1.4 1.7,2.0 Ip=1.1, Bt=5.4, ASP,FSP,ISP scanning at 0.65, 0.85, 1.05s
ASP - Good. East is floating (shorted to head)
FSP -
ISP - ok

Next: go to inner limited shot based on 1060316018
Apr 12 2006 03:02:55:833PM1060412022Brian LabombardShot 22 Inner wall limited NL04=1.2 Ip=0.78, Bt=5.4, No probes scanning

Next: Repeat
Apr 12 2006 03:02:31:227PM1060412023Brian LabombardShot 23 Inner wall limited NL04=0.8,1.0,1.0 Ip=0.79, Bt=5.4, ASP scanning at 0.65, 0.85, 1.05s
ASP - Scan to LCFS. East probe is now working!

Next: Repeat
Apr 12 2006 03:14:10:523PM1060412024Brian LabombardShot 24 Inner wall limited NL04=0.9,0.9,1.1 Ip=0.8, Bt=5.4, ASP scanning at 0.65, 0.85, 1.15s
ASP - Scan to LCFS. All probes in I-V sweep mode.
last scan corresponds to GPI time

Next: repeat with ASP in floating mode

Apr 12 2006 03:38:31:320PM1060412026Brian LabombardShot 26 Inner wall limited NL04=0.8,0.9,1.0 Ip=0.8, Bt=5.4, ASP scanning at 0.65, 0.85, 1.15s
ASP - Scan to LCFS. All probes in floating mode.
last scan corresponds to GPI time

Next: Repeat with ASP in I-V mode and smaller GPI puff

Apr 12 2006 04:07:15:583PM1060412027Brian LabombardShot 27 Inner wall limited NL04=0.67,0.86 Ip=0.8, Bt=5.4, ASP scanning at 0.65, 0.85, 1.15s
ASP - Scan to LCFS. All probes in I-V
last scan corresponds to GPI time

Next: Load from 1050602023, run on segment#2 LSN, program density 0.4 at 0.5s ramping to 1.0 at 1.2s

Apr 12 2006 04:33:55:163PM1060412028Brian LabombardShot 28 LSN, NL04=0.53,0.58 Ip=0.4, Bt=4, ASP-dwell, FSP,ISP scanning at 0.65, 0.85, 1.15s
Marfe leading to disruption at 0.88s

Next: try again with probes pulled back.

Apr 12 2006 04:38:05:507PM1060412029Brian LabombardShot 29 LSN, NL04=0.56 Ip=0.4, Bt=4, ASP-dwell, FSP,ISP scanning at 0.65, 0.85, 1.15s
Simlar to 28 - Marfe leading to disruption at 0.84s

Next: Try again with lower density

Apr 12 2006 05:07:30:840PM1060412030Brian LabombardShot 30 LSN, NL04=0.4-0.7 Ip=0.4, Bt=4, ASP-dwell, FSP,ISP scanning at 0.65, 0.85, 1.05s
ASP in dwell mode - data looks ok
end of run

Physics Operator Comments
Apr 12 2006 08:58:01:383AMIan HutchinsonLoad from 1060324023. Segments 1 and 2 are active. Has 22ms fill puff.
Load.
Apr 12 2006 09:15:45:900AM1060412003Ian HutchinsonA problem with the interferometer is reported.
Some shot cycle problems prompt this as another test shot.
Apr 12 2006 09:43:23:790AM1060412004Ian HutchinsonPlasma. Disrupts at 1.65s in ramp down.
EF1U is saturating at 5kA at 1.3s.
EF2s are zeroing in rampdown.
OH2s seem fairly clear of their limits.

Bring start of EF4 ramp to 1.45s to try to alleviate EF2 zeroing during
rampdown. Otherwise a repeat.
Apr 12 2006 09:58:00:103AM1060412005Ian HutchinsonPlasma disrupts at 1.444s. Density drifts up to nl04=1.75
Looks as if we run out of OH2 Voltage and then the slow vertical position control is lost.

Lower nl04 demand to 1.2 trying to compensate the excessive density.
Apr 12 2006 10:06:54:760AM1060412005Ian HutchinsonPlasma disrupts at 1.444s. Density drifts up to nl04=1.75
Looks as if we run out of OH2 Voltage and then the slow vertical position control is lost.

Lower nl04 demand to 1.2 trying to compensate the excessive density.
Apr 12 2006 10:06:55:430AM1060412005Ian HutchinsonPlasma disrupts at 1.444s. Density drifts up to nl04=1.75
Looks as if we run out of OH2 Voltage and then the slow vertical position control is lost.

Lower nl04 demand to 1.2 trying to compensate the excessive density.
Apr 12 2006 10:08:41:777AM1060412006Ian HutchinsonPlasma. Disrupts at 1.64s. Got nl04=1.5

Raise nl04 demand to 1.35 at 1s.
Make the EF4 current rampdown demand more aggressive.
Apr 12 2006 10:24:13:527AM1060412007Ian HutchinsonDisrupts at .88s. A big radiative event at the peak insertion of the second scan.
Apr 12 2006 10:43:37:790AM1060412008Ian HutchinsonPlasma. Disrupts at 1.65s.

Enable 40ms argon puff.
Make further duration of EF4 ramp.



Apr 12 2006 10:54:37:697AM1060412009Ian HutchinsonPlasma: disrupts at 1.65

Found that OH2 limits were set to 26 instead of the advertized 30kA.
Set to 30kA. OH1 was not at 35 either; it was 27. Increase that to 33kA.

Go to Upper null by moving to segment 3. This already has an aggressive EF4 swing
starting at 1.49s. Set nl04 demand to 1.3
Apr 12 2006 11:13:44:930AM1060412010Ian HutchinsonPlasma upper null. Disrupts at 1.7s. Got 1.35 nl04.

Raise nl04 demand to 1.45.
Move EF4 rampdown to 1.47s
Apr 12 2006 11:22:58:290AM1060412011Ian HutchinsonPlasma early disruption because we loose interferometer

Switching to zmeter feedback. Load wire 11 from 1051130013.
It has a demand of 0.07 and gives 0.6e20.
To get an nl04 of 1.4 we would need 0.07*(1.4/.6)**2 =.38 demand
Wolfe says shot ten actually had .3, so split difference .34 set.
Apr 12 2006 11:49:24:480AM1060412012Ian HutchinsonPlasma but a totally unwanted one. This is apparently because of bringing
up a PCS safe to examine the settings. I guess that is not allowed.

Therefore go back to shot 11. Load wire from 1051130013. This actually seems to have values of .1, so to get 1.4 we would need .1*(1.4/.6)**2 = .54. But I don't trust that calculation, so I use 0.35 for nlzmeter. Also the gain seems to be
wrong. So I think this is incorrect. Do it again. This time I get what looks like the previous values: 0.07.
Apr 12 2006 12:11:39:543PM1060412013Ian HutchinsonDisrupts at .35s owning to OH2 crowbar fault.


Apr 12 2006 12:24:40:380PM1060412014Ian HutchinsonPlasma. Got nl04 1.6. OH1 trip in rampdown.

Tweak the nlzmeter rise to try to get rid of marfe.
Apr 12 2006 12:32:10:070PM1060412015Ian HutchinsonPlasma.

Lower nlzmeter to .32, and slightly slower rise.
Apr 12 2006 12:46:55:087PM1060412016Steve WolfeShot#16: Wolfe taking over as physop for shot 17.
Contrary to what Ian said, there is a large pg3 pre-program
in seg3 which may be contributing to the Marfe and early density
rise, which was still present on #16.

Drop PG3 from 70 to 30 before .2sec, zero after
Apr 12 2006 12:59:53:897PM1060412017Steve WolfeShot#17: Drop PG3 in seg3 from 70 to 30 before .2sec, zero after
plasma, only got to 1.3 on nl04, instead of 1.6. Looks like it could
use more gain on the nl_zmeter, now that I've removed the feedforward.
However, I think that wick is all the way up.
Gas still turning off after 1sec

Brian wants to go to 1.8 next shot.
Apr 12 2006 01:11:32:600PM1060412018Steve WolfeShot#18: Increase nl_zmeter program from .32 to .40
Increase late pg3 maint level from 0 to 20V
I need to increase either the factor or the vontroller to
provide more output voltage. Both are at or near their PCS limits,
which are completely meaningless with DPCS of course, but may
be enforced someplace in the code that would cause a problem
if I load it. See what I get this time, and consider raising
the factor if it doesn't get close to what I want.

Result: plasma, no marfe (it went away last time), nl04=1.7
Getting close. I've got plenty of headroom on the valve, if I can convince
dpcs to ask for it.
Apr 12 2006 01:30:29:960PM1060412019Steve WolfeShot#19: Increase nl_zmeter from .40 to .48
plasma to 1.53 sec still disrupting in rampdown.
nl04 crapped out. TS claims ne around 3e20
nl01 is giving 3.2e20/m^2 which must be looking through the divertor.

Brian wants some more. Increase demand and late feed-forward.
Apr 12 2006 01:46:00:193PM1060412020Steve WolfeShot#20: Increase nl_zmeter from .48 to .58, pg3 from 20 to 35V
plasma to 1.4sec, things are definitely on the rails.
OH1 may be voltage limited here, and oh2U.
TS says ne=3.7e20. TCI is OTL. Jim will look in cell to try to fix whatever.

next: Brian says to try to get this density earlier.
Apr 12 2006 02:06:59:240PM1060412021Steve WolfeShot#21: Increase nl_zmeter point at .55sec to .58, add some more pg3 between .35 and .55sec
Increase nl_zmeter factor from 2.0 to 2.5 and controller from 50 to 62.5, gain from 9 to 10
plasma to 1.33sec. nl04 above 2e20, rising; ECE temp around 800eV

Brian is done with this condition. Now change to SZ's limiter expt.
Apr 12 2006 02:33:39:337PM1060412022Steve WolfeShot#22:Brian is done with this condition. Now change to SZ's limiter expt.
Import seg4 from 1060316018, seg2. I need to use nl_zmeter, since TCI is still flakey.
The zmeter trace on that shot went from .23 to .44V.
Load the nl_zmeter wire from seg3 and change program to .23; will adjust later.
Turn off seg3, turn on seg4. This is supposed to be an 800kA round limited discharge,
nebar around 2e20, ne0=2.4e20 before the NINJA puff.

plasma. looked limited to me. nl04~1.2e20, Got some early runaways.
glitch around 0.5sec, could be crossover.
Need to drop the density by about 25%. Gas is actually off until abot .5sec




Apr 12 2006 02:53:51:227PM1060412023Steve WolfeShot#23: Lower nl_zmeter demand before 0.5sec.
Zero argon puff. The target shot actually had no gas after .15sec.
That means I've probably gone the wrong way on the early nl_zmeter,
since shot 22 had no gas then at all. Oh well, see what it does.
Matt is agitating to put the neon back, but I'm going to leave it
off for one shot. Ian can put it back.

plasma, it did bounced, only a few runaways.
nl04 looks about like the old shot.
Ian's back, he can deal with final tweaks



Apr 12 2006 03:06:00:943PM1060412023Ian HutchinsonPlasma.

Reinstall the Argon/Neon puff. Other than that, just repeat.
Apr 12 2006 03:17:41:227PM1060412024Ian HutchinsonPlasma. Disrupts at about 1.3s owing to ninja puff.

Import segment 1 from 1060328008, the current standard shot.
Set EF4 to -1340A (splitting the difference between -1350 and the standard shot's -1330A). Had to tweak 02 and 06.
Apr 12 2006 03:28:23:507PM1060412025Ian HutchinsonFizzle. Bz ramp rate is still ridiculously slow.

Remove the BR offset of +.2mT
Apr 12 2006 04:00:40:490PM1060412026Ian HutchinsonPlasma.

Rcur offset to 1800 from 1600.
Apr 12 2006 04:17:34:960PM1060412027Ian HutchinsonPlasma.

Load from 1050602023.
Need to recalculate predictors. Therefore reuse current. And import seg 2 only.
Call predictors.
Copy B21_proj and zero.
Copy nlzmeter and adjust ramp to .2.
Load clean.
Apr 12 2006 04:31:44:630PM1060412028Ian HutchinsonDisrupts at .85s. Appears to be some kind of injection.

EF3 voltage moved from 5ms/2500V to 6ms/2600V.
Apr 12 2006 04:52:46:637PM1060412029Ian HutchinsonDisruption very similar to previous.

Lower density
Disable argon puff.
Lower density to .14 nlzmeter.
Apr 12 2006 05:01:54:077PM1060412030Ian HutchinsonAfter many travails with mdsplus hangs. Plasma till 1.5s.

Engineering Operator Comments
ShotTimeTypeStatusComment
108:32:09:980AMTestBadShot cycle Test
208:44:58:743AMTestBadShot Cycle Test
309:07:58:087AMTestOkShot Cycle Test
409:28:04:103AMPlasmaOk
509:42:37:400AMPlasmaOk
609:56:35:383AMPlasmaOk
710:09:30:087AMPlasmaOk
810:21:55:620AMPlasmaOk
910:35:17:400AMPlasmaOk
1010:52:23:883AMPlasmaOk
1111:05:03:823AMPlasmaOk
1211:22:49:837AMPlasmaOk
1311:54:28:477AMPlasmaOk
1412:10:00:430PMPlasmaOk
1512:22:52:147PMPlasmaOk
1612:35:40:553PMPlasmaOk
1712:54:32:117PMPlasmaOk
1801:07:32:960PMPlasmaOk
1901:21:13:147PMPlasmaOk
2001:33:58:803PMPlasmaOk
2102:00:12:977PMPlasmaOk
2202:25:14:117PMPlasmaOk
2302:49:41:367PMPlasmaOk
2403:03:28:490PMPlasmaOk
2503:16:05:193PMPlasmaOk
2603:28:53:880PMPlasmaOk
2703:56:15:040PMPlasmaOk
2804:15:31:587PMPlasmaOk
2904:28:37:617PMPlasmaOk
3004:41:40:860PMPlasmaOk