Alcator C-Mod Run 1051206 Information

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Miniproposals
Miniproposal:389
Date Filed: 2/5/2004
Title:CNPA Testing and Calibration
First Author:Vincent Tang
Session Leader:Vincent Tang (shots 1-17)
Miniproposal:437
Date Filed:10/23/2005
Title:Field Reversal Experiments
First Author:Alex Ince-Cushman
Session Leader:Alex Ince-Cushman (shots 18-36)

Operators
Session leader(s):Vincent Tang,Alex Ince-Cushman
Physics operator(s):Steve Wolfe
Engineering operator(s):Andy Pfeiffer,Gary Dekow,Bill Parkin

Engineering Operator Run Comment
MP#389 CNPA testing. SL: V. Tang MP#437 Edge poloidal rotation. SL: A. I

Session Leader Plans
Entered: Dec 5 2005 04:26:21:820PM
Author: Alex Ince-Cushman
Session Leader Plan - 1051206
Field Reversal and Edge Poloidal Rotation - MP 437

Session Leader: A Ince-Cushman
Physics Operator: S Wolfe

This half run day will be used to finish up the run on 1051202.
1 â?? Get a few repeatable USN shots with EDA-H modes (if there is enough RF power)
2 â?? A series of inner wall limited plasma with an elongation scan

SETUP:
Key diagnostics:
Hirex, NeSoXs, Thomson, Edge Thomson, GPC, Bolometer arrays, McPherson, Chromex, CXRS, scanning probe

Gas puffs: Argon/Neon puff: 40ms at 0.3s (Neon at 2psi, Argon at 1psi)


Part 1) USN EDA H-modes
-----------------------------
Load shot 1051202022, or possibly a similar shot from the first half of the run day.

Key parameters are
Bt=5.6 T
Ip=0.8 MA
NL_04 (target)=1.0e20 m-2
RF waveform: Flat top ON at 0.7 OFF at 1.3 at 3 MW

Part2) Inner wall limited
-------------------------------
The following shots will be loaded for the kappa scan
1.6 -> 1051109017
1.4 ->1050819002
1.2 -> 1050615025

Entered: Dec 6 2005 07:33:10:383AM
Author: Vincent Tang
1st half of day, MP#389:

Primary objective: determine if He and Boron/Mo impurities are affecting CNPA spectra. To do this, I plan to run 3-4 shots per bulk plasma condition and try to vary the different impurities in the plasma. We can than compare both the passive and beam induced spectra(shot-to-shot) and see if there's any effect. The fast ion CXRS experiment will also piggyback.

We will need the McPherson to measure Boron and Mo lines together, chromex to measure He and Boron together, and the CXRS diagnostic to try to get Boron density as a function of radius. In addition we will have the HeII diode. Hopefully we can get a good relative measurements of the different impurities.

DNB setup: Fire DNB at 1.0s, max pulse length and power allowed.

RF setup: E-port only, on at t=0.5 to 1.5 flatop at specified powers of 0.5-1MW.

Plan:
1. Establish target shot, LSN but like 1050818005, as discussed in Wolfe's PO Plan. Get good passive and active CNPA data. (1-2 shots?). Start at 0.5MW and go up to get optimum signal.

2. Repeat first shot, but with He puff at t=.3; try to get He conc. to be in the 1-5% range. See if CNPA spectra are affected. Repeated with bigger puff if required (1-2 shots).

3. Repeat first shot, but now inner wall limited. The Boron and MO should increased significantly. Note effect on CNPA signal. (1-2 shots).

4. Repeat inner wall limited shot with He puff at t=.3. (1-2 shots).

Time permitting, move to higher power and repeat.

Physics Operators Plans
Entered: Dec 5 2005 02:43:03:723PM
Author: Steve Wolfe
Engineering setup and physop plan for Tuesday, 1051206

MP#389 CNPA testing. SL: V. Tang
and
MP#437 Edge poloidal rotation. SL: A. Ince-Cushman
and maybe 
MP#441 ICRF Coupling studies SL: A. Parisot

Run starts at 09:00 (lockup at 08:30) and ends at 17:00

Overnight ECDC in HELIUM, pressure=5e-5. Stop two hours before run
Bake at 60C

All transmitters in RUN-ON by 08:30AM

Power systems as on 1051122030

A-coil in standard configuration {+Dtop -Dbot -Jtop +Jbot},
enabled, start-time=0.3sec

Gas setup:
----------

fill B-top with 6psi D2 Hybrid ENABLED (PG4)
fill B-side lower with 1psi Ar+2psi Neon Hybrid DISABLED (PG1)
fill B-side upper with 15psi He4 Hybrid DISABLED 
fill B-Main with 30 psi D2 Hybrid ENABLED 
fill NINJA with 10psi D2 leave DISABLED
** Note changes on B-side Upper fill and B-main pressure **

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

Torvac setup: Gate valves open

Run Plan for MP#389 (1st half of run)
--------------------------------------
This may change, see SL_PLAN

Start with 5.4T, 600kA LSN discharge, 
like 1051122030 but reduced elongation, nl04~5e19.
Presently loaded as seg2 in /home/wolfe/pcs_trees/pcs_1051206000
Want RF from E-port only from 0.5sec - 1.5sec, .5-1.0MW
DNB on (timing?) at max available current, pulse length
NO B-side lower puff for this part of the run. 

Establish discharge to SL's taste, then begin puffing helium (PG2)
Start with 100msec puff at 201msec, believed to give ~5%. Adjust
based on spectroscopic data, CNPA signal. 

Change to inner wall limited discharge (in seg3) and repeat. 
Not sure if SL wants helium puffing into limiter shots as well. 

Run Plan for MP#437 (2nd half of Run)
--------------------------------------

Pick up where they left off on Friday, 1051202022.
Use segment 4 presently loaded in 1051206000, which is
based on the USN shot with some adjustments. If that proves
problematic, maybe go to 1051123009 with suitable parameter 
changes. Turn Argon/Neon puff on (PG1), helium puff off (PG2).

When done with the upper null, go to inner wall limited discharges. 
Probably base this on the limiter case from the morning, with
increased current and density. 

Change elongation in limiter discharge as requested by SL. This will
be done primarily with CLEARIN. 

Run Plan for MP#441 (3rd half of run)
---------------------------------------

If there is time, A. Parisot wants to re-run some cases from 
Monday's run with Helium 4 majority. Purge B-main and fill 
with 40psi Helium 4; leave B-top with 6psi D2. Run as many 
cases as will fit in the rest of the day. 

Post Run: Begin warming up the machine in preparation for
an argon vent next week. 

 
  



Session Leader Summaries
Entered: Dec 6 2005 06:28:40:707PM
Author: Alex Ince-Cushman
Session Leader Summary

MP 437 - Field Reversal and Edge Poloidal Rotation

Session Leader: A Ince-Cushman
Physics Operator: S Wolfe

This was a continuation of the run from 1051202. The run switched over to MP 437 after shot 17. We began by trying to reproduce one of our best shots from that day, 1051202015 (LSN EDA H-mode plasma). We were not able to reproduce steady h-modes in LSN so we didnâ??t even try going to USN. After that we started running inner wall limited plasmas (shot 23) in an attempt to do a scan in elongation.

Of the 19 attempted shots we had 7 fizzles, 5 disruptions, and one no power shot which left us with 3 LSN and 3 inner wall limited plasmas (two at kappa = 1.6 and one at 1.35).


All shots had the puff starting at 0.3s with 2psi Neon and 1psi Argon

18 LSN 3 H-modes 60ms - H-modes mostly ELM free
19 LSN - 60ms - Only 0.8 MW of RF so no H-modes
20 Fizzle -
21 Fizzle -
22 LSN 5 H-modes 60ms - 2MW of RF but several trips
23 Fizzle
24 In-Lim - 60ms - 2MW of RF no trips, kappa = 1.6
25 In-Lim - 80ms - Disrupted at ~0.5
26 Fizzle
27 Fizzle
28 In-Lim - 60ms - kappa = 1.6
29 In-Lim - 60ms - Disrupted at 0.65s
30 Fizzle
31 No power shot
32 In-Lim - 60ms - kappa = 1.35
33 Fizzle
34 In-Lim - 60ms - Disruption at 0.59s
35 In-Lim - 60ms - kappa = 1.35, disrupted at 1.15s
36 In-Lim - 60ms - Disrupted at 0.37s

Entered: Dec 9 2005 01:42:30:947PM
Author: Vincent Tang
---12/06/05---
MP: CNPA testing and calibration

The CNPA impurity run went well today. We were able to investigate passive CNPA spectra from plasmas with He, Boron, and Mo impurities. Most significantly, the DNB performance was excellent at 7A and 150ms pulse length. This resulted in an active CNPA signal about 6-7X greater than the passive signal, which will allow us to isolate the impurity issues from the passive spectra. In addition, the good beam performance allowed us to track boron densities into the plasma core through the CXRS diagnostic. At the least, the great beam signal on all 3 F-top channels will allow us to secure fast ion temperatures in the core for these shots.

We had 15 shots out of 17 attempts. The first few shots were LSN low density(~nel~4e19), low RF (.5MW) shots. They established a clean base from which we could use for comparison to later impurities laden shots. The discharges with He puff after these base shots had ~2-4x higher CNPA count rate but semingly similar passive spectra shape. The inner wall shots had a lot of impurities, especially Boron and Mo, but their effect on the CNPA spectra was not as obvious as the He puff-shots. Further detailed analysis is required. An issue we had was that after a shot with He puff, it took several shots before the He content in the plasma returned to normal.

The 4 scenarios outlined in the plan was completed. We hence took some shots with D antenna instead of E in order to increase the relative Mo concentration for the LSN shots. (A suggestion from Matt based on D and E data from previous runs). We also took some data at 1/4MW; even at 1/4MW, the CNPA signal was still strong because of the low density.

We had decent measurements of all the relevant impurities, along with their relative ratios--

McPherson: Boron (edge) vs. Mo (core)
Chromex: Boron (edge) vs. He (edge)
Hirex: Mo (core)
CXRS: Boron vs. radius into R~75cm.

Lastly, we had a couple of lock-mode shots without sawteeth that are interesting as a test for fast ion diffusion.

Thanks to everyone for their good work; especially the beam and spectroscopy guys for all of their help, and the PO for getting good low density plasmas.

Physics Operator Summaries
Entered: Dec 6 2005 06:14:57:800PM
Author: Steve Wolfe
This run day was definitely a mixed bag. 
The first half-day went pretty well. Vincent got
through all of his planned program and actually 
got some additional points, with some lower power shots, 
and a comparison of D- and E-port, which apparently 
still has the feature that D is more of a Mo source
than E. 

Running the low density divertor discharges was no problem, 
as we were actually puffing gas at 0.4 and 0.5e20 nl4. 
The limiter shots were done with higher elongation than 
originally specified, since the CNPA signals were plenty 
high enough. The limiter shots were programmed just by 
changing CLEARIN from the initial LSN cases. 
We had problems with locked modes on the limiter cases, 
even though the B21_PROJ feedback was on, and the 
computed 21 amplitude was under a gauss. The locked modes
showed up on shots 10 and 12, after tweaking the outer gap. 
Raising the density from .5 to .6 early in the shot got rid of them.
Also, running with a large outer gap as on #9 and 13 also got 
rid of it, although 13 actually had somewhat higher density 
due to the helium puff. These shots are probably worth some 
further study, and provided a good non-sawtoothing comparison
for the CNPA dataset. 

Through the first half of the run I had to continually increase 
the pre-puff to try to reduce runaways and avoid duds. PG4 program
eventually got up to 55msec, with ratiomatic pressure above .08mTorr. 
Raising the RCUR offset from 1600 to 2000 actually seemed to get 
rid of the bounces and runaways in these low density shots, although
the breakdown came a little later on the shots with the higher 
RCUR offset. 

The second half of the run, MP#437, was much more problematic. 
Running more normal densities changed the wall conditions, and
the very high pre-puffs and RCUR offset had to be undone; this 
wasn't unexpected, but nevertheless we ended up with a very high 
proportion of fizzles that never completely stabilized. 
We ended the day with pg4 at 37 to 38msec, close to where we 
started. The shots that went had good looking startups, but
these were not really robust against disruptions. 

Furthermore, a lot of the shots that ran did not run well. We started off by
trying to repeat a Lower null shot from Friday, and took six 
tries to decide that the boronization was too far gone to attempt
steady h-modes in upper null. We therefore never actually attempted
upper null, but instead went straight (?) to the limiter cases. 

The base limiter condtion was loaded from 1051109017, with elongation
~1.6, 800kA, 5.4T; the argon/neon puff was increased to 60msec.
These cases were plagued by more fizzles and also 
early disruptions, associated with quite cold (possibly hollow) 
temperatures during current rise. The idea was to do an elongation scan,
but we only got one lower kappa=1.35 case, and the best shot of 
that #32 had no TS data. Attempted repeats had disruptions and 
fizzles; shot#35 made it to 1.13sec before getting killed by an 
injection, but it also had early problems. The last shot #36 was an
attempt at a kappa=1.2 case, but it disrupted before .4 sec, again 
with current-rise internal disruptions preceeding the final crash. 
I'm not sure how to get these lower elongation limiter cases to run
reliably. The problem seems to be in the current rise, and may be
due to accumulating neon or argon from previous attempts. None of these
last shots had any runaways or bouncy startups, but there were 
already incipient problems at the start of segment 2. If the 
neon puffing hadn't been essential to the experiment I would have
tried turning it off, but that wasn't really an option since
a good shot with no neon wouldn't have been useful anyway. 

To add to the difficulties, we had two spurious IOC faults on oh2l,
one during CHECK on shot#31 which resulted in a no-power shot, and one
at or before 80msec on #33, which had already fizzled by the time
of the fault. The voltage and current traces from the supply showed 
big negative spikes around 30ms which do not appear on the bus diagnostics. 
This looks like an instrumentation problem about to get worse, 
and should probably be checked out during the shutdown. 

The multiple fizzles and duds, and the low current normal shots in the
morning, were hard on the coax resistance. We got a lot of warnings,
all below 2.9uOhm. There were no new records, and no obvious trends
except that consecutive fizzles gave slightly higher resistances than
singles. 

Scorecard: 

    Test/NoPower    1
    Duds            2
    Fizzles         6
    Plasmas        27 (including 5 early disruptions)
    --------       --
    Shots          36

Session Leader Comments
Dec 6 2005 08:16:20:790AMVincent TangAll four CNPA channels operational and within normal parameters. Ap set at notch 20.

Fast ion CXRS channel set to vertical channel, 2051 Spec at 4833 setting, ap opened to 10 microns.

Toroidal CXRS shutter opened.
Dec 6 2005 09:10:08:710AM1051206001Vincent Tangvery low density shot (nel 3e-19), excellent beam and passive signal. Up the density a bit, and I think we have a good basis shot.
Dec 6 2005 09:22:52:087AM1051206002Vincent TangExcellent data and shot, but no McPherson data. Repeat.


Dec 6 2005 09:56:15:117AM1051206003Vincent TangGood shot, good data; went into h-mode at the end. No McPherson data again; switching to hirex for Mo measurements

Beam signal is ~5 times higher than base.

Puff on next shot.
Dec 6 2005 09:51:27:447AM1051206004Vincent TangDud, Repeat


Dec 6 2005 10:05:10:007AM1051206005Vincent TangHe Puff at .3. Higher count rate, possible spetra change. Double puff to check.
Excellent data.


Dec 6 2005 10:10:03:773AM1051206006Vincent TangDisrupted early. Repeat.


Dec 6 2005 10:33:37:133AM1051206007Vincent TangGood shot, doubled He puff has slightly softer spectra. Repeat shot 3 to make sure things are really different(no puff next shot).
Dec 9 2005 11:48:33:220AM1051206008Vincent TangNo He puff..definitly seeing lower count rate on Ch2(7x less roughly).

Next shot: Inner wall limited, no puff.

boron and Mo should go up.

-12-09-05
Hmm...7x might be over-estimating it...most of the shot is roughly twice less.



Dec 6 2005 10:59:43:867AM1051206009Vincent TangMuch more MO/B, but no Mcpherson and HIREX data. More counts on CNPA, softer spectra compared wtih shot 3 (t=1.2 to 1.3)

repeat to get McPherson and HIREX data.



Dec 6 2005 12:03:21:627PM1051206010Vincent TangLock mode, no sawteeth. Spectra at 1.2 to 1.3 is softer (and lower counts) compared with shot 3 and 9. Could be good shot to see effects of sawteeth.

Next: repeat to get rid of lock mode.

I think on this shot I double-checked that the Bill's Mcpherson was opened. Also opened aperture to 100 microns.



Dec 6 2005 11:33:42:023AM1051206011Vincent TangLock mode gone, but density is sloping; CNPA passive data shows rise in higher energy, but impurities supposily didn't change.

Repeat and try to get flat nel4.





Dec 6 2005 11:58:33:877AM1051206012Vincent TangLock mode again....No beam on last shot. Lock mode signal weaker except for large spike at ~275keV.

next: inner wall limited with large puff.





Dec 6 2005 12:07:23:050PM1051206013Vincent TangSofter spectra, but could be because of density rise. No huge jump in signal as seen in LSN He puff case.

Next: LSN with D this time, to try to increase relative Mo concentration.
Dec 6 2005 12:24:18:800PM1051206014Vincent TangDefinite spectra changes between this shot and shot 3; zeff is higher for shot 14.

Next: go to .25MW.






Dec 6 2005 12:42:36:767PM1051206015Vincent Tanggot .3MW LSN. Good signal, weaker as expected.

next: go back to .5MW to try to see data with lower He/B conc.






Dec 6 2005 12:54:38:173PM1051206016Vincent TangHe is still sticking around.

Next: final shot--one more .25 MW
D, hopefully with less He.

Change 2051 back to 4880, with 30 micron opening.







Dec 6 2005 12:57:21:533PM1051206017Vincent TangGood data, last shot.

Thanks everyone, espeically Matt and Ken.
Dec 6 2005 01:20:17:970PM1051206018Alex Ince-CushmanLSN based on 1051202015
2MW RF, from 0.7 - 1.3
Neon/Argon puff at 0.3s for 60ms with Neon at 2psi and Argon at 1psi

RF tripped, no EDA H-mode

For next shot increase nl04 to 1.0
Dec 6 2005 01:29:38:457PM1051206019Alex Ince-CushmanLSN - same as previous shot but with nl04 increased to 1.0

Neon/Argon puff same as last shot (0.3s for 60ms with Neon at 2psi and Argon at 1psi)

Only 0.8MW of RF so no H-modes
Dec 6 2005 02:09:17:360PM1051206022Alex Ince-CushmanLSN - 2MW of RF but there were a few trips. It looks unlikely that we will get steady EDA like H-modes so we are going to move to inner wall limited discharges for the next shot.

Neon/Argon puff same as last shot (0.3s for 60ms with Neon at 2psi and Argon at 1psi)

Dec 6 2005 02:44:49:690PM1051206024Alex Ince-CushmanInner wall limited discharge, ~ 2MW of RF (no trips), I = 0.8MA

good shot

Neon/Argon puff same as last shot (0.3s for 60ms with Neon at 2psi and Argon at 1psi)

Dec 6 2005 02:47:22:500PM1051206025Alex Ince-CushmanInner wall limited discharge
Disrupted at about 0.5s. Then neon/argon puff was increased from 60ms to 80ms but neon and argon radiation was similar to the previous shot. McPherson data suggests a Moly injection may have been the culprit.


Dec 6 2005 03:25:10:453PM1051206028Alex Ince-CushmanInner wall limited discharge
kappa at 1.6. Good shot. For the next shot will try moving down to kappa = 1.4


Neon/Argon puff same as last shot (0.3s for 60ms with Neon at 2psi and Argon at 1psi)
Dec 6 2005 03:37:25:220PM1051206029Alex Ince-CushmanInner wall limited discharge
Aimed for kappa of 1.4, but discharged disrupted early. Try for kappa = 1.4 again.
Dec 6 2005 04:44:40:953PM1051206032Alex Ince-CushmanInner wall limited

Kappa at 1.35. Pretty good NeSoXs signal levels.

Neon/Argon Puff: 0.3s for 60ms
Dec 6 2005 05:02:55:563PM1051206035Alex Ince-CushmanInner wall limited
Kappa at 1.35, disrupted at 1.155.
Neon/Argon Puff: 0.3s for 60ms

Physics Operator Comments
Dec 5 2005 01:39:29:053PMSteve Wolfe
Getting set up for the 1051206 run.
There will be two experiments: Vincent's CNPA run in the
morning, and Alex Ince-Cushman MP#437 in the afternoon. 
Vincent wants a limiter discharge like 1050818005 and a "similar" 
lower null. I have imported 1050818005 into seg3, updated
all the magnetics and Ip predictors, setup B21_PROJ feedback and
saved as 1051206000 in ~/pcs_trees.

This was a low elongation shot, and rather than trying to make
it into a LSN I am going to start from a 600kA LSN from 
November and try to reduce the elongation, etc. to suit.
Import Seg 2 from 1051122030 into Seg2. 
  TF current to -150000, PG3 to zero. 
  NL04 from 0.6 to 0.4e20 (Vincent says he wants 5, but 4 is what 
    was in the limiter shot. 
  ZXU from .05 to .07 to try to reduce elongation
  Copy PG2 puff from seg3 (100msec starting at .201sec)

I think that for aic's run we can start from the limiter case, 
with current increased to 800kA. For his upper null case, Bob
recommended starting from 1051202022, which ran but has several
unpleasant features, not least that shots 23 and 24 disrupted. 
Alex says that he does not need the small inner and outer gaps
on this one. Also, I notice that the ZCUR program is inconsistent
with the startup, since it starts at zero and goes to -.005,
while the startup ends at -.009, so we are jerking the plasma 
up and then back down early. I'll work with this as a starting
place, but if I get into trouble, a replacement could be 1051123009.

Load 1051202022 Seg 3 into Seg4.
  Increase CLEARIN by .005 (to -.01, -.005)
  Copy ZCUR from seg2, then change points at .381 and after to -.005
    (I'm not sure he needs this either, we normally run upper nulls 
  LOad wire 9 from seg2 B21_PROJ, set integrator C to start at 0.3,
   zero A-coil current and move last point from 10.0 to 3.5sec
Build all segments and save as /home/wolfe/pcs_trees/pcs_1051206000
     at ZCUR=0).  

Dec 5 2005 03:38:55:427PMSteve Wolfe
Still hacking at the pcs setup. 
Note that the chopper voltage in seg2 is at
100V instead of zero. Change it and resave 1051206000
  



Dec 6 2005 08:02:28:553AMSteve Wolfe
Continuing to set up PCS for today's run.
Load from /home/wolfe/pcs_trees/pcs_1051206000

Joe had all kinds of startup problems yesterday, but I'll
start with seg1 from 1051205003 anyway; increase pg4 to 35msec
I may want to play with Bz control in seg1. Try putting an offset
of -.007 into the bz_0 on wire 7, and monitor the aout; I may
also try copying in a waveform. 
Note ic_ef4u=-1330
 br_0 = 0

Per SL plan for first part of run, change He4 puff from 
0.2 to 0.3sec in seg2, copy to seg3. Note that this will 
be off for the first several shots. 

We'll probably want to tweak at the equilibrium for a few
shots. SL wants minimum elongation to reduce opacity to his
fast neutrals.

Note: Second half SL's plan calls for three different source 
shots for his limiter elongation scan, including two from
last summer. The low kappa case
is practically touching on the outside, and disrupts in 
flattop. I'm probably going to ignore these and either use
a modified seg3 (low kappa) or start from his suggested 1051109017
(kappa=1.6). Note that for USN he asks for 5.6T, so I need to 
check if he wants that for the limiter cases as well.  

Do a load, get one factor warning, two wirename warnings in seg1.
touch the wires, reload. It loaded ok, despite the fact that I 
accidentally moved points on wires 6 and 10 instead of 7 and 9.
Put the values back, just so PCS_compare doesn't flag diff's.
And it complains again? Change them again, this time on the
correct wires; no complaints. Put it back and reload; ok.
Do a PCS_compare. Diff's on oh1 and oh2. modify and reload.
OK, now PCS_compare only flags diffs on BZ_0, IC_EF4U, PG4.

Load at  6-Dec-2005 07:58:26.00
Open tree /home/wolfe/pcs_scratch      -1
Open tree done



Dec 6 2005 09:05:23:883AM1051206001Steve Wolfe
Shot#1: base pressure at INIT=1.3e-7;in PULSE=1.1e-7
plasma, lots of runaways. 
nl04=3e19, kappa=1.6. It's actually puffing gas through
this shot. 

Next: raise nl04 demand, increase pg4


Dec 6 2005 09:18:30:600AM1051206002Steve Wolfe
Shot#2:  raise nl04 demand to 5.0e19
pg4 from 35ms to 37ms
plasma, still have runaways, but fewer. 
NL04=4.9e19
Br0 looks a little negative. Looks like the startup 
could still use a little more gas. 

next shot: add 2ms to pg4 (pushing my luck?)

Dec 6 2005 09:29:41:930AM1051206003Steve Wolfe
Shot#3: pg4 from 37 to 39msec
plasma, still have some runaways.
late breakdown, around 8msec
Got an H-mode at the end of the flattop.

next shot: back off pg4 a little

Dec 6 2005 09:50:28:477AM1051206004Steve Wolfe
Shot#4: pg4 from 39 to 38msec
Enable B-side upper puff for this shot (He4 100ms puff)
p0=9.5e-7 in pulse
dud. OH currents look a little funny (too close together), 
but the fields don't look bad. Br0 still a little negative

next: raise pg4 to 40msec

Dec 6 2005 09:59:08:867AM1051206005Steve Wolfe
Shot#5: pg4 38msec to 40ms
Enable B-side upper puff for this shot (He4 100ms puff)
plasma, looked like more runaways
bouncy on startup, almost lost it. 

next: raise pg4 some more!


Dec 6 2005 10:16:59:633AM1051206006Steve Wolfe
Shot#6: pg4 40ms to 42msec
Increase helium puff from 100ms to 200ms
early disruption, .316sec. lots of runaways. 
Still bouncing in startup. 
Got another oh coax warning, and we'll probably get another 
next time. 

next: add a pg3 puff in seg2 at 50V from 100 to 200msec
increase pg4 another 2ms

Dec 6 2005 10:29:22:617AM1051206007Steve Wolfe
Shot#7: pg4 42ms to 44msec
 add a pg3 puff in seg2 at 50V from 100 to 200msec
plasma, no runaways
breakdown a little late, 7msec. No bounce. Br0 is 
more normal looking, Bz getting a little more positive. 

oh2u is barely double swinging on these, so we may keep
getting coax issues. Just squeeked by on this one, 2.37uOhm.
It did go down at the end of the shot though. 

next shot: ic_ef4 down by 5A

Dec 6 2005 10:40:32:053AM1051206008Steve Wolfe
Shot#8:  ic_ef4 from -1330 to -1335
Disable Helium puff. 
plasma, runaways came back some. 
Bounce on startup again; either should have raised pg4 or 
not dropped ef4

next shot: raise pg4 2msec
Go to limiter discharge

Dec 6 2005 10:56:14:977AM1051206009Steve Wolfe
Shot#9: pg4 from 44 to 46 msec
Go to limiter discharge, just use seg2:
  CLEARIN from .001 (about) to -.02
  RCUR from .662 to .652
  Helium puff still disabled
plasma, some runaways, still bouncing in startup
elongation is 1.5, limited, outer gap is a little bigger
at 1.5 to 1.7cm, but RF doesn't seem to mind. 

next shot: leave pg4 alone, raise RCUR a smidge

Dec 6 2005 11:13:02:163AM1051206010Steve Wolfe
Shot#10: RCUR from .652 to .656 early, .654 late
leave zxl low in rampdown to prevent late diversion. 
No startup changes until I see how the gas evolves from the
limiter case. 

plasma, still with runaways, stilll bouncing. Need to raise pg4 again.
May have hit a locked mode at .74sec, despite B21 feedback.
Still diverts in rampdown. 

Try raising early pg3 puff in seg2 some more


Dec 6 2005 11:22:43:867AM1051206011Steve Wolfe
Shot#11: pg4 to 48msec!
Try raising early pg3 puff in seg2 some more
plasma still with runaways, still bouncing. 
No locked mode this time, but early density is higher,
around 6e19, then falling; looks the same as 9 at beam time

next shot: up to 50 on pg4

Dec 6 2005 11:40:17:087AM1051206012Steve Wolfe
Shot#12: pg4 to 50msec
decrease pg3 puff between .2 and .5sec to try to flatten 
the density without getting a locked mode, I hope.
plasma, smaller runaways, but got the locked mode back.
Looks very similar to shot#10, onset a little later, around .87sec.
No bounce, but a later breakdown, 7msec
No beam on that shot. 

There will be a cell access for TCI. 
Others also. 

Dec 6 2005 12:01:24:923PM1051206013Steve Wolfe
Shot#13: Reload seg2 from shot 9, but with helium puff
This one had the larger gap, but no locked mode
plasma no runaways (small burst early).
No locked mode, I think the he4 puff substituted 
for the pg3. 

next shot: Back to LSN, puff off.  


Dec 6 2005 12:13:20:000PM1051206014Steve Wolfe
Shot#14: Reload seg2 from shot 8, LSN again. helium puff off
RF will pulse from D instead of E 
plasma, bounce in startup, some runaways 
RF looks ok, density nice and flat. 

next: More pg4 again

Dec 6 2005 12:26:33:563PM1051206015Steve Wolfe
Shot#15: pg4 from 50 to 52msec. I think this is the most I've ever 
used for pre-puff. 
Lower RF power for this one, still from D-port
plasma, runaways again. Still bouncing with pressure close
to 80uTorr! 
Density is a little lower this time. RF looks happy at 300kW.

next: Kick pg4 up to 55 


Dec 6 2005 12:40:37:410PM1051206016Steve Wolfe
Shot#16:pg4 from 52 to 55msec
Raise rf power back to 0.5MW again (repeat of 14)
plasma again with runaways. Still bouncing. 
Try increasing RCUR offset in seg1. 

Dec 6 2005 12:56:40:237PM1051206017Steve Wolfe
Shot#17: RCUR offset from 1600 to 2000
back to .25MW from D-port, repeating #15
plasma, no runaways, no bounce, later breakdown 7.7msec

Next: on to Alex's half of the run

Dec 6 2005 01:11:30:737PM1051206018Steve Wolfe
Shot#18: on to Alex's half of the run
Load seg3 from seg2 of 1051202015 (LSN repeat from last week)
  seg2 off, seg3 on. PG2 puff from 40 to 60msec. Enable b-side lower
  initial gap moved out, rcur from .663 to .655, getting rid of jog. 
 This is 800kA, 5.6T, 8e19, LSN
No startup changes this time. 

plasma full length, H-modes. 
Still a late breakdown, no runaways. 
Outer gap between 1.5 and 2cm. RF trips on D and J

next raise nl04 to 1.0e20

Dec 6 2005 01:24:32:377PM1051206019Steve Wolfe
Shot#19:raise nl04 to 1.0e20
I'm tempted to start reducing pg4, but leave it for this shot.
plasma full length, no h-modes, no runaways, breakdown still late
D and J both faulted out as soon as they came on, only got about
800kW from E-port. 

next shot: pg4 down to 50msec

Dec 6 2005 01:35:06:487PM1051206020Steve Wolfe
Shot#20: pg4 from 55 to 50msec
fizzle. I guess I tweaked too soon. 
Or maybe not enough, looks like too much gas, or Bz 

next: ef4 down 5A, pg4 down 2 more msec

Dec 6 2005 01:48:28:767PM1051206021Steve Wolfe
Shot#21: pg4 from 50 to 48msec
EF4 from -1335 to -1340 
Maybe I should undo the RCUR change? Leave it for this one.
Another fizzle. breakdown still late, Bz rising too fast
Bz seemed to go the wrong way.

next: RCUR back to 1600

Dec 6 2005 02:02:18:220PM1051206022Steve Wolfe
Shot#22: RCUR back to 1600
pg4 at 48msec, ef4 at -1340A

plasma, 5 hmodes, breakdown still late,
RF with lots of faults, but mostly stays on.
no runaways, no bounce
Bz still too positive, barely made it.

next: ef4 down 10A, pg4 down 3msec

Dec 6 2005 02:13:17:627PM1051206023Steve Wolfe
Shot 23: ef4 from -1340 to -1350,
 pg4 from 48ms to 45ms. 
Load seg2 from 1051109017 (Limiter case, eout=1.6 800kA 5.4T 1e20)
 Increase pg1 from 50 to 60msec
Fizzle. Earlier breakdown, Bz is down, still choking. 

next: PG4 to 40msec

Dec 6 2005 02:28:32:673PM1051206024Steve Wolfe
Shot 24: PG4 from 45 to 40msec
plasma, limited, disrupts in rampdown ~1.7sec
Late breakdown again, 8.3msec
No bounce no runaways. RF is happy, around 2.3MW

next shot: repeat with no RF

Dec 6 2005 02:42:12:877PM1051206025Steve Wolfe
Shot#25: repeat with no RF
Raise PG1 Argon/Neon puff from 60 to 80msec
Decrease PG4 from 40 to 38msec

plasma disrupts at 0.5sec. Too much neon?
Bd at 7msec, no runaways, no bounce.
Bz is more negative on this one. 

next shot: Argon/neon puff back down to 60msec


Dec 6 2005 02:50:10:813PM1051206026Steve Wolfe
Shot#26: repeat with no RF
 Argon/neon puff back down to 60msec
fizzle. Should have dropped the pre-puff after the disruption

next: pg4 down 2ms

Dec 6 2005 03:03:55:673PM1051206027Steve Wolfe
Shot#27:pg4 from 38 to 35msec, working our way back down.
pg1 pulse at 60msec, still no RF
dud? Dropped it too far.

next: PG4 back up to 38ms

Dec 6 2005 03:16:15:550PM1051206028Steve Wolfe
Shot#28: PG4 back from 35 to 38ms
If this doesn't go, ECDC for 15minutes in D2

plasma to 1.7sec, no bounce no runaways

next shot: start elongation scan

Dec 6 2005 03:36:57:673PM1051206029Steve Wolfe
Shot#29:start elongation scan
CLEARIN from -.02 to -.04
LPI gate valve enabled, Pellet will fire at 1.3sec
No startup changes this time.

plasma disrupted at .66sec, marfe starts at .4sec
Looks colder right from the startup, current rise is
a little slower. Never sawtooths. 
I've got the clearin ramp in starting at 0.3sec, could
delay that, and delay the density ramp, but I think this 
one had problems before it got that far. 

Dec 6 2005 03:43:26:627PM1051206030Steve Wolfe
Shot#30: Delay clearin point to 0.5sec, slow down density ramp to .65sec
fizzle, not unexpected after the disruption. 

next: drop the target density, since we're going for a
shorter plasma

Dec 6 2005 03:54:21:643PM1051206031Steve Wolfe
Shot#31: Decrease pg4 from 38 to 37msec; probably should 
have done that before, but last time I dropped it we got a dud. 

Decrease nl04 target from 1.0 to 0.8, since the
path length is going to be shorter.
PF breaker pulled out in CHECK, no power shot.  



Dec 6 2005 04:12:59:080PM1051206032Steve Wolfe
Shot#32: pg4 from 38 to 37msec; probably should 
have done that before, but last time I dropped it we got a dud. 

Decrease nl04 target from 1.0 to 0.8, since the
path length is going to be shorter.
  
plasma to 1.7 sec, kappa=1.35, nebar = 1.9e20
No pellet. Thomson didn't get reset after the power room 
access, so no TS data

next: repeat

Dec 6 2005 04:27:59:893PM1051206033Steve Wolfe
Shot#33: repeat
fizzle, PF breaker pulled, crowbar 
late breakdown 12.7msec. 
The power system fault came later, oh2l at 80msec
don't know why the breakdown is so late.

next: pg4 back to 38msec

Dec 6 2005 04:45:02:767PM1051206034Steve Wolfe
Shot#34:pg4 from 37 to 38msec
Still trying to repeat shot 32 with TS

Another early disruption around 0.56sec
There were a couple of internal disruptions between
0.2 and 0.4 sec. 
Current rise and startup look ok, te gets to 2keV
but never sawtooths. Gas turns off hard at segment switch
It did the same on 32, but that one was a lot happier. 

PG4 back to 37 and try again

Dec 6 2005 04:52:27:097PM1051206035Steve Wolfe
Shot#35:pg4 from 38 to 37msec
Still trying to repeat shot 32 with TS

plasma to 1.13sec, almost lost it early again
very cold and possibly hollow before .2sec, but
survived, barely. kappa=1.35

next (and last) shot: Try for lower elongation ~1.2

Dec 6 2005 05:10:21:550PM1051206036Steve Wolfe
Shot#36:Try for lowest elongation ~1.2
CLEARin to -.06, speed up current rise
increase pg3 between .1 and .2
Drop nl04 target from .8 to .7e20

Disrupts at .36 sec, lots of internal disruptions
during current rise. Current never made it over 700kA. 
Never sawtoothed. Again, under 1keV at .1sec. Early
current rise looks smooth, but it's cold. 
Not exactly a good one to leave on the drum, 
but that's the end of the run. 

Engineering Operator Comments
ShotTimeTypeStatusComment
108:58:59:053AMPlasmaOk
209:11:50:850AMPlasmaOk
309:24:20:710AMPlasmaOk
409:41:18:227AMPlasmaOk
509:54:33:867AMPlasmaOk
610:07:15:307AMPlasmaOk
710:19:56:337AMPlasmaOk
810:33:23:227AMPlasmaOk
910:50:10:913AMPlasmaOk
1011:04:13:510AMPlasmaOk
1111:17:29:150AMPlasmaOk
1211:34:01:430AMPlasmaOk
1311:57:20:093AMPlasmaOk
1412:09:39:207PMPlasmaOk
1512:23:02:673PMPlasmaOk
1612:36:38:330PMPlasmaOk
1712:52:31:987PMPlasmaOk
1801:05:24:987PMPlasmaOk
1901:18:05:720PMPlasmaOk
2001:31:22:127PMPlasmaOk
2101:43:39:970PMPlasmaOk
2201:56:27:737PMPlasmaOk
2302:09:47:893PMPlasmaOk
2402:22:11:813PMPlasmaOk
2502:34:38:673PMPlasmaOk
2602:47:22:127PMPlasmaOk
2703:00:09:597PMPlasmaOk
2803:12:37:347PMPlasmaOk
2903:26:30:017PMPlasmaOk
3003:40:02:627PMPlasmaOk
3103:52:32:410PMPlasmaBadIOC OH2L, no power shot
3204:06:08:783PMPlasmaOk
3304:18:47:610PMPlasmaBadIOC OH2L during pulse
3404:35:08:610PMPlasmaOk
3504:47:50:660PMPlasmaOk
3605:00:35:127PMPlasmaOk