Alcator C-Mod Run 1060331 Information

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Miniproposals
Miniproposal:430
Date Filed: 7/26/2005
Title:Localization of the effect of boronization
First Author:Bruce Lipschultz
Session Leader:Earl Marmar (shots 1-13)

Operators
Session leader(s):Earl Marmar
Physics operator(s):Jim Irby
Engineering operator(s):Ed Fitzgerald,Sam Pierson,Bill Parkin

Engineering Operator Run Comment
PO:Irby SL:Marmar,Lipschultz EO:Fitzgerald,Pierson,Parkin MP430 Between

Session Leader Plans
Entered: Mar 31 2006 08:47:33:760AM
Author: Earl Marmar
Engineering setup:
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Power systems as on 1060329012
A-coil configuration: normal [+Dtop -Dbot -Jtop +Jbot] and enabled.
C-coil Start=0.3sec, Invert=2.0sec

ICRF in Run-on by 7:15AM; desire ~ 3 MW steady for all shots

Gas Setup:
----------
fill B-top 6psi D2 Hybrid Enabled (PG4)
fill B-side lower 1 psi Argon Hybrid Disabled (PG1)
fill B-side Upper 12 psi He-4 for ecdc Hybrid Disabled (PG2)
fill B-main 40psi D2 Hybrid Enabled (PG3)
NINJA: 10psi D2

*** Boronization system set up for between-shot boronization
*** Because of the late start, we will begin with plasma, prior to boronization, to check out the RF systems and the flux loop that was acting up on 1060329 (f25)
*** We will be using 20% diborane 80% He mixture which has twice the amount of diborane as usual.

Enable ECE, VUV, Z-bolo shutter for all plasma shots; these must be disabled
for between-shot boronization

The A-Side TV camera shutter must be CLOSED before the boronizations (before the run and for the rest of the day).

The MSE shutter must be CLOSED before the start of the run, and remain closed
throughout the day.

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SL plan
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MP430 - Between shot boronization

Assume 10 minute boronization length to start with. Pressure 5
mTorr. Pause at center of each scan. Steady ECDC, no pulsing.

To reduce fizzles after boronization the prefill is greatly reduced
see 1050810xxx and wait to get the pressure down to <2.5x10-6 Torr
We will start using static fill, rather than the prepuff.

-1) Establish plasma operation with RF.

0) Boronize for 20 minutes (scan 50-92 cm, no pulsing). We will skip the post boron ECDC in helium.

1) Re-establish plasma after the 20 minute boronization.

2) Boronize sequence (1 shot to measure effect, 2nd shot to determine
if it has worn off) using 10 cm wide scans to cover from 90 to 50
cm. Work from outer major radius inward in 10 cm steps.

3) Once done with the scan, return to the most effective
location to examine reproducibility.

4) Scan using 5 cm stepsize on either side of the best location.

Potential next steps

- Switch in 10% diborane 90% He mixture bottle.

- Compare the usual boronization including pulsed ECDC with leaving
the ECDC on steadily during the period.

- If not done earlier then reduce the length of boronizations now to
10 and 5 minutes length (4 shots min. if not including fizzles).

- Compare boronization lifetime by comparing D&E heated versus J heated.

Physics Operators Plans

Session Leader Summaries
Entered: Mar 31 2006 05:12:13:540PM
Author: Earl Marmar
MP 430 - between shot boronization (localization)

The goals were not met today. We managed one 20 minute boronization (50, 92, 70) with no pulsing. The following discharge (shot 10) had a steady EDA H-mode with only 1 MW of RF, H89~1.4. Because J-port was not sufficiently reliable to continue with the 10 cm scan boronizations, the run was handed over to RF conditioning from shot 13.

Physics Operator Summaries
Entered: Mar 31 2006 05:30:13:267PM
Author: Jim Irby
Not a great day. We started out expecting to run the boron localization experiments, but were unable to get reliable rf power and decided to do more rf conditioning.

We boronized the machine form 50 to 92 cm before shot 007. I dropped the static fill to 1e-5 Torr, but that was not enough to avoid a fizzle on shot 008. Looking back at data from August something closer to 6.5e-6 Torr would have been better. It was clear from the CIII signals that the boronization had been effective, even without a full plasma discharge. When we finally got a plasma on shot 010 we had a very nice extended EDA H-mode. H/(H+D) was 3% to 4%.

On shot 18 we had a disruption at 0.87 s caused by a large injection. This event resulted in a fizzle followed by three duds. We finally did 10 minutes of ECDC that produced a fizzle, followed by a plasma. On shot 025 we had a similar disruption at 0.9 s, however, reducing the fill from 1.7 to 1.4e-5 Torr produced a plasma on shot 026.

We also puffed he/b2d6 today from 0.15 to 0.20 s to help with the antenna conditioning from shot 015 to shot 027. It did appear to help. The antennas continued to perform better after we turned it off on shot 028. We were eventually able to get over about 4.2 MW of power into the plasma from the e and j antennas. d port antenna will need looking at on Monday.

Session Leader Comments
Mar 31 2006 09:25:42:570AM1060331002Earl Marmarplasma

no boronization yet

RF very trippy
Mar 31 2006 09:46:23:220AM1060331003Earl Marmarplasma

a little more RF power; stays in l-mode at 2 MW, goes into h-mode as rf trips off.
Mar 31 2006 09:46:42:033AM1060331004Earl Marmarplasma

short elm-free h-modes
Mar 31 2006 10:39:27:380AM1060331006Earl Marmarplasma

a little more RF power

ratty h-modes
Mar 31 2006 11:10:07:393AM1060331007Earl Marmarprior to this shot

20 minute ECDC boronization
scan: 50, 92, dwell at 70, no pulsing

no helium ECDC

fizzle


Mar 31 2006 11:10:23:860AM1060331008Earl Marmarno additional boronization

fizzle
Mar 31 2006 11:25:00:617AM1060331009Earl Marmardud
Mar 31 2006 11:41:56:200AM1060331010Earl Marmarplasma

nice steady eda h-mode, 1 MW RF (E port only)

H_89 ~ 1.4
Mar 31 2006 12:03:50:867PM1060331011Earl Marmarrepeat (no additional boronization)

plasma

mostly 1 MW (E-port only), l-mode during RF, h-mode at end of RF pulse, mostly ohmic
Mar 31 2006 12:21:57:700PM1060331013Earl MarmarI am signing off as session leader.

For now, the run is switching to efforts to diagnose j-port.

Physics Operator Comments
Mar 31 2006 09:12:20:160AM1060331001Jim IrbyUsing static fill --- request is 1.7e-5 Torr on IGT (no DNB)

Loaded shot 1060329012 from Wednesday

Assuming that fizzle/dud on 23/24 on Wednesday was F25 effect
Bob Granetz has checked loops and connectors. Thinks it's in vacuum issue.

IGT pressure to setpoint within 60 s of going into init

fizzle ---

nothing wrong with fields, but breakdown very late


Mar 31 2006 09:34:39:230AM1060331002Jim IrbyNo changes --

plasma into rampdown --- no rf

breakdown still somewhat late
Mar 31 2006 09:40:42:263AM1060331003Jim IrbyNo changes --

plasma into rampdown --- some rf

h-mode following rf

h-mode before rf too (last shot also)



Mar 31 2006 09:53:36:317AM1060331004Jim IrbyNo changes -- probably a mistake

plasma into rampdown --- breakdown still late

e-port looks better
2.7 MW max rf




Mar 31 2006 10:09:24:260AM1060331005Jim IrbyEF4 to -1330 from -1340 A

plasma into rampdown --- startup is better

BART mode


Mar 31 2006 10:22:43:983AM1060331006Jim IrbyNo changes

plasma into rampdown

some j and e

will boronize before next shot
Mar 31 2006 11:03:01:810AM1060331007Jim IrbyNo DPCS changes

boronize from 50 to 92 cm with dwell at 70 cm. No pulsing of ECDC
using 20%/80% b2d6/He bottle at 30 psi
TC3 pressure about 3 to 6 mTorr after some excursions beyond 8 mTorr
20 minutes of boronization done --- no helium ecdc followed

static fill request to 1.0e-5 Torr

fizzle

CIII has almost gone away completely during startup (.005 down to < .001)

sparker had a couple of arcs




Mar 31 2006 11:11:11:253AM1060331008Jim Irbystatic fill back to 1.7e-5 Torr

fizzle --- breakdown a little later


Mar 31 2006 11:30:39:493AM1060331009Jim Irbystatic fill to 1.5e-5 Torr

dud


Mar 31 2006 11:41:58:107AM1060331010Jim Irbynot really knowing what to do we went back to 1.7e-5 Torr static fill

plasma into rampdown ---- extended eda h-mode, 114 kJ, 1 MW rf only

h-factor steady 1.4

prad, 2pi low


Mar 31 2006 12:04:13:710PM1060331011Jim Irbyno changes to pressue or startup

plasma ---- late h-mode --- one trick boronization

h/(h+d) 4%



Mar 31 2006 12:18:35:950PM1060331012Jim Irbyno changes

plasma but no j-port --- l-mode


Mar 31 2006 12:32:30:913PM1060331013Jim Irbyrepeat with j3 and j4 at different times

e-port turned off for this shot

a little power out of d and j4



Mar 31 2006 12:44:17:393PM1060331014Jim Irbyrepeat

plasma


Mar 31 2006 12:53:21:973PM1060331015Jim Irbyenabled diborane puff from 0.1 to 0.175 s
shorter pulse than on 1060329 because the diborane regulator is set to 30 rather than 10 psi.

forgot to load it!

disruption from diborane puff ---- puff was from 0.1 to 0.250 s


Mar 31 2006 01:14:52:527PM1060331016Jim Irbydiborane puff from 0.150 to 0.200 s --- load/clean

plasma into rampdown

j3 and j4 running together at up to 1.8 MW

H/(H+D) about 3%

briefly had 130 kJ


Mar 31 2006 01:27:57:610PM1060331017Jim Irbyno changes --- Steve does a little tuning

plasma into rampdown

j-port looking much better


Mar 31 2006 01:33:06:893PM1060331018Jim Irbyrepeat

z-bolo should be opened for this shot

disruption at 0.87 s --- large injection
117 kJ at end of shot


Mar 31 2006 01:51:44:697PM1060331019Jim Irbyrepeat

Steve thinks antenna is "cleaning up"

fizzle --- didn't drop the pressure following disruption...

carbon III returns

lost TCI data --- Polarimeter test shot did it in


Mar 31 2006 02:06:10:423PM1060331020Jim Irbytry again

dud


Mar 31 2006 02:21:03:427PM1060331021Jim IrbyBr0 +.0002 T

dud!

br0 did go up a bit, but didn't fix problem

Mar 31 2006 02:26:10:960PM1060331022Jim Irbystatic fill to 1.9e-5 Torr

dud

will ecdc in D2 for 10 minutes


Mar 31 2006 03:01:51:100PM1060331023Jim IrbyECDC in D2 for 10 minutes

static fill back to 1.7e-5 Torr

fizzle


Mar 31 2006 03:25:19:483PM1060331024Jim IrbyBr0 offset back to 0.000

plasma --- almost lost it in current rise --- injection

MARFE

117 kJ

H/(H+D) at 4%


Mar 31 2006 03:35:33:473PM1060331025Jim Irbyno changes

disruption at 0.9 s

injection at 0.832 s -- j-port trips then bigger injection



Mar 31 2006 03:48:36:367PM1060331026Jim Irbystatic fill to 1.4e-5 from 1.7 e-5 Torr

plasma into rampdown

117 kJ again

early small injection


Mar 31 2006 04:03:21:170PM1060331027Jim Irbynl04 request from 1 to 0.8e20 /m^2 load/clean

will leave static fill at 1.4e-5 Torr

plasma into rampdown --- late breakdown


Mar 31 2006 04:20:11:113PM1060331028Jim Irbyturned off he/diborane puff

1.5e-5 Torr for static fill

plasma into rampdown --- startup better

122 kj at 3 MW of rf


Mar 31 2006 04:33:33:290PM1060331029Jim Irbyrepeat

plasma into rampdown --- startup better still


Mar 31 2006 04:48:22:530PM1060331030Jim Irbyno changes

plasma into rampdown --- breakdown later

Bz0 up a mT

144 kJ --- 4.3 MW


Mar 31 2006 05:06:00:570PM1060331031Jim Irbyef4 from -1330 to -1340 A

dud

F25 baseline offset of -1.4e-2 (may have started on shot 30)
Bz0 from shot 30 could have been bogus and no change was really needed


Mar 31 2006 05:19:37:637PM1060331032Jim Irbyef4 back to -1330 A

plasma into rampdown

138 kJ at 3.9 MW




Engineering Operator Comments
ShotTimeTypeStatusComment
108:59:23:467AMPlasmaOk
209:12:17:067AMPlasmaOk
309:26:56:790AMPlasmaOk
409:41:20:843AMPlasmaOk
509:55:39:050AMPlasmaOk
610:10:54:493AMPlasmaOk
710:53:58:353AMPlasmaOk
811:07:15:407AMPlasmaOk
911:19:50:113AMPlasmaOk
1011:32:23:400AMPlasmaOk
1111:46:23:923AMPlasmaOk
1212:02:40:193PMPlasmaOk
1312:16:08:620PMPlasmaOk
1412:30:12:320PMPlasmaOk
1512:46:47:267PMPlasmaOk
1612:59:38:663PMPlasmaOk
1701:15:06:777PMPlasmaOk
1801:27:52:140PMPlasmaOk
1901:40:51:083PMPlasmaOk
2001:54:03:900PMPlasmaOk
2102:07:55:173PMPlasmaOk
2202:23:03:333PMPlasmaOk
2302:54:33:067PMPlasmaOk
2403:09:45:070PMPlasmaOk
2503:24:15:653PMPlasmaOk
2603:37:41:287PMPlasmaOk
2703:54:44:557PMPlasmaOk
2804:07:53:563PMPlasmaOk
2904:20:54:067PMPlasmaOk
3004:34:01:993PMPlasmaOk
3104:50:54:343PMPlasmaOk
3205:07:05:070PMPlasmaOk