Alcator C-Mod Run 1050215 Information

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Miniproposals
Miniproposal:298a
Date Filed: 5/20/2002
Title:C-Mod Plasma Startup
First Author:Jim Irby
Session Leader:Steve Wolfe (shots 1-17)

Operators
Session leader(s):Steve Wolfe
Physics operator(s):Steve Wolfe
Engineering operator(s):Bill Cochran,Gary Dekow,Bill Parkin

Engineering Operator Run Comment
MP#298a (Startup/Conditioning) and MP#355 (ICRF Conditioning)

Session Leader Plans
Entered: Feb 14 2005 05:18:44:290PM
Author: Steve Wolfe
Run Plan for Tuesday, 15-Feb-2005

MP#298a (Startup/Conditioning)
and
MP#355 (ICRF Conditioning)

Start from a repeat of 1050211031 (800kA Lower Null) to evaluate the H/D
after Friday's disruptive cleanup run and overnight ECDC (plus D2 backfill
over the weekend).

Set up and run 800kA upper null shots. A possible (untried) starting point
is in segment 3 of 1050211031.

Increase density with D gas puffing as far as possible, consistent with
getting non-resistive, non-disruptive plasmas.

Provide target plasma for ICRF conditioning (D- & E-port) as requested by
Wukitch, et al.

If time and the program permit, sometime after 5:00PM load 1050210021 and
complete MP#399: change dpcs cycle time to 300 usec, 50usec.

Physics Operators Plans
Entered: Feb 14 2005 05:02:44:573PM
Author: Jim Irby
Overnight ECDC in D2, bake at 60C

Engineering setup:
Power systems as on 1050211031

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 30 psi D2 Hybrid DISabled (PG2)
>>> fill (former) C-side with 30 psi D2 Hybrid Enabled (PG3)

Torvac Setup:
--------------
GV1 closed, Bypass to RGA open
Torus gate valves closed in Pulse for 5min after shot

Gate valves:

ECE open
Z-bolo/shutter open

Session Leader Summaries
Entered: Feb 15 2005 07:13:55:487PM
Author: Steve Wolfe
Run Summary for Tuesday, 15-Feb-2005

MP#298a (Startup/Conditioning)
MP#355 (ICRF Conditioning)
SL: wolfe
PO: Irby (1-9), wolfe (10-17)

The run got off to a slow start due to a vibration on the alternator,
which required them to drop back to speed 2 and ramp back up. The first
plasma attempt (shot#5) was taken at 15:30, and resulted in a short,
resistive, early disruption.

Following another cycle test, we got a good lower null plasma on shot#7 and
moved on to upper null on shot#8. We got a number of upper null shots (eight
to be exact), and increased the nl04 to 7e19. Brian was getting good
pressures on the E-top and Penning gage. He seemed to be finding a
correlation between the Penning pressure and the sweep out of the upper
strike point toward the gusset. I tried controlling this with strkpsi
control (shots 12-13) but got disruptions due to railing EF2U. Need to
look into this more carefully. We then continued upper nulls for 15-16,
moving the x-point during the shot. RF got up to 1MW from E-port. D has
an instrumentation problem (broken cable in the cell).

Shot 17 I loaded 1050210021 into segment 4 and Marco raised the
dpcs cycle to 300 usec to complete the scan of MP#399, but it fizzled.
We still need to collect this shot.

Combined scorecard:

Tests 5
Duds 0
Fizzles 2
Plasmas 10 (including one ugly short disruption)
------- --
Shots 17

Physics Operator Summaries

Session Leader Comments
Feb 15 2005 12:28:26:640PM1050215001Steve WolfeShot#1: data system cycle test only.
Got device not triggered on the gas valve signals
(PHA INCAA_16). The pha decoder has an init failure
"entity not found".

Joe Bosco and Yuri are investigating.
Feb 15 2005 02:35:20:140PM1050215002Steve WolfeShot#2: Another cycle test, while the alternator is coming back up
to speed.

Gas valve signals are back. Other signals look ok.
Feb 15 2005 03:06:22:360PM1050215003Steve WolfeShot#3: Another cycle test for JHI.
Ratiomatic camac failed on this one; no-X.
Feb 15 2005 03:15:18:983PM1050215004Steve WolfeShot#4: Another cycle test for JHI.
Changing the gas puff.
Still no ratiomatic
Feb 15 2005 03:46:46:530PM1050215005Steve WolfeShot#5: Go for plasma
Disrupts at 280msec?
Gets very resistive and turns over early.
Could be overgassed
Feb 15 2005 04:09:53:657PM1050215006Steve WolfeShot#6: Cycle test after Joe rearranges the camac highway.
There's a late gas puff from someplace at .15sec
That seems to be after the pg3 puff.
Feb 15 2005 04:25:45:577PM1050215007Steve WolfeShot#7: Another plasma try.
plasma full length
H/D .1 to .15

next shot: upper null
Feb 15 2005 04:40:02:467PM1050215008Steve WolfeShot#8: try for upper null, using the seg3 I set up Friday
plasma full length, looks upper null to me.
Outer gap is getting small toward the end, inner
gap is ~9mm.
Got some rf

next shot: increase clearin 5mm and straighten out rcur.

Feb 15 2005 05:00:19:453PM1050215009Steve WolfeShot#9: increase clearin 5mm and straighten out rcur.
plasma full length
outer gap ~1,5, inner ~1.3, n/nc=1.1
Looks pretty good.

next shot: raise the density a little.

Physics Operator Comments
Feb 15 2005 10:50:54:513AMJim IrbyECDC overnight at 2e-4 Torr in D2
Bake at 60 C
RGA trend data did not show up this morning --- sent note to Joe and Yuri
Feb 15 2005 12:13:41:687PM1050215001Jim IrbyLoaded shot 1050211031 from last Friday.
Did a load/clean


This was a cycle test - no power

Problem with alternator vibration (probably oil temp related) --- will have to ramp down and then ramp back up

Feb 15 2005 02:53:58:970PM1050215002Jim Irbycycle test

check gas puff, rga before/after data.

Feb 15 2005 03:09:08:717PM1050215003Jim Irbyrepeat of shot 2
Feb 15 2005 03:25:10:640PM1050215004Jim Irbypg3 from 35 to 100% in segment 1

igt rose to 2.6e-4

mass 4 on the rga after data is not much higher than on shot 3??


Feb 15 2005 03:48:50:953PM1050215005Jim Irbyloaded in 1050211031 from last Friday as fiducial

pg3 back to 35 from 100%.

279 ms of plasma --- not good as a fiducial from last Friday

igt at 1.5e-3

h/(h+d) at 200 ms is 7%

having problems with gas data --- Joe is making changes to the CAMAC highway

Feb 15 2005 04:14:19:577PM1050215006Jim Irbylong delay to modify CAMAC highway --- trying to get back pressure data

cycle test to check CAMAC

igt 1.2e-4 Torr

Feb 15 2005 04:32:17:577PM1050215007Jim Irbypg3 from 18 to 16 ms

plasma into rampdown

h/(h+d) at 10% level

Feb 15 2005 05:02:02:013PM1050215009Jim Irbyrcur reduced at 1.5 s

clearin from 0.000 to +0.005

argon enabled

plasma into rampdown

h/(h+d) 21% (same as shot 8)
Feb 15 2005 05:13:18:157PM1050215010Steve WolfeShot#10: Wolfe replacing Irby as physop
raise the density to 7e19 and increase Ar from 40->50ms for JR
disrupts at 1.7sec, probably an ef2 goes to zero problem.
rf hanging in at 0.4MW from E, D has an instrumentation problem
in the cell.
H/D .25 to .3

next shot: repeat
Feb 15 2005 05:47:25:547PM1050215011Steve WolfeShot#11: repeat, except ramp ef4 down further at 1.5sec
plasma full length, 7e19, 750kW from E

next shot: more Argon for JR, try strksi control
Feb 15 2005 06:02:34:203PM1050215012Steve WolfeShot#12: pg1 to 80ms, try strksi control gain=4 from .6 to 1.5sec
drop zxu gain from 8 to 2 on same interval

plasma to 1.54sec, strkpsi is somewhat restrained, but
moves out near the end, then there is a big lurch when I go
back to zxu. EF2U rails at 1.25sec, that's where we lose
strkpsi control.
Big gas burst on the disruption.

next shot: turn off the zxu, see if that helps
Feb 15 2005 06:15:32:373PM1050215013Steve WolfeShot#13: zxu gain to zero, back up to 2 at 1.5
rxu gain doen from 4->2

plasma to 1.25sec, that was worse. Lost ef2u early.
That was the wrong way to go.
Enough on strkpsi, back to xpoint control
and move it down
Feb 15 2005 06:24:16:540PM1050215014Steve WolfeShot#14:Enough on strkpsi, back to xpoint control
and move it down by a cm during the shot

fizzle, should have dropped pg4

next shot: pg4 to 13msec
Feb 15 2005 06:44:17:690PM1050215015Steve WolfeShot#15: pg4 to 13ms
move zxu down by a cm during the shot
Tom had to kill the eng buslv cpci on this shot in init.

plasma full length, bus rogowski signals came through too.
Didn't get the fluxihh things though.
RF around 800kW from E
Feb 15 2005 06:46:09:830PM1050215015Steve WolfeShot#15: pg4 to 13ms
move zxu down by a cm during the shot
Tom had to kill the eng buslv cpci on this shot in init.

plasma full length, bus rogowski signals came through too.
Didn't get the fluxihh things though.
RF around 800kW from E

next shot: raise pg4 back to 15ms
Feb 15 2005 06:53:28:800PM1050215016Steve WolfeShot#16: raise pg4 back to 15ms
plasma to 1.7sec,
Got 1MW from E

next shot: load 1050210021 into seg4 and run it with dpcs dt=300usec
Feb 15 2005 07:08:00:910PM1050215017Steve WolfeShot#17: load 1050210021 (lower null) into seg4 and run it with dpcs dt=300usec
for MP#399.

fizzle.

Engineering Operator Comments
ShotTimeTypeStatusComment
112:05:22:297PMTestOkData System test shot with Gas, No power
202:31:18:420PMTestOk
302:58:12:733PMTestOk
403:10:17:343PMTestOk
503:29:37:420PMPlasmaOk
604:01:56:797PMTestOk
704:17:44:623PMPlasmaOk
804:30:21:327PMPlasmaOk
904:54:20:280PMPlasmaOk
1005:07:01:093PMPlasmaOk
1105:38:52:983PMPlasmaOk
1205:51:40:343PMPlasmaOk
1306:06:18:360PMPlasmaOk
1406:20:53:763PMPlasmaOk
1506:33:18:353PMPlasmaOk
1606:49:50:313PMPlasmaOk
1707:04:11:237PMPlasmaOk