Alcator C-Mod Run 1050608 Information

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Miniproposals
Miniproposal:326
Date Filed: 8/26/2002
Title:D, E, and J-port Antenna Evaluation and Comparison
First Author:Steve Wukitch
Session Leader:Steve Wukitch (shots 1-21)

Operators
Session leader(s):Steve Wukitch
Physics operator(s):Jim Irby
Engineering operator(s):Andy Pfeiffer,Bill Byford,Bill Parkin

Engineering Operator Run Comment
automatically entered by signon - please replace with real comment

Session Leader Plans
Entered: Jun 8 2005 07:13:18:580AM
Author: Steve Wukitch
Plan:

Following the 6 Torr vent to air on Monday, we have baked the machine
at 80 to 120 C for approximately 24 hours while running ECDC in D2.
It will not be clear until we make discharges how well we have done in
recovery.

As a test of recovery:

. produce three or four fiducial discharges in D2

. monitior H/(H+D) and determine where we are in the cleanup

If H/(H+D) is low continue switch to He plasmas MP326

We will continue with antenna recovery effort and investigate whether
He discharges have improved antenna power and voltage characteristics.
We will begin with LSN and switch between LSN and USN to determine if
magnetic geometry affects antenna power and voltage characteristics as
observed in D discharges.

If H/(H+D) is high move to MP#412a

Improved hydrogen-to-deuterium changeover using radiative terminations
and disruptions.

Physics Operators Plans
Entered: Jun 7 2005 05:27:58:717PM
Author: Jim Irby
Engineering setup for Wednesday, 08 June 2005

RF Conditioning in Helium or Disruptive Cleanup

Session leader: Wukitch, Lin, Blip
Physics operator: Irby

ECDC overnight in D2 with 60C bake

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

Power systems as on 1050526026 (1.0 MA, 5.4 T, SNL fiducial)

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 Hybrid DISABLED (PG1)
leave B-side upper with whatever Hybrid disabled
fill B-main (C-side) with 30 psi D2 Hybrid enabled (PG3)

Be prepared to switch B-main with 30 psi Helium after first few discharges.

Enable the following gatevalves: Z-bolo shutter, ECE, VUV

--------------------------------------------------------------
ICRF Setup: All transmitters in run on at 08:30.

--------------------------------------------------------------

Plan:

Following the 6 Torr vent to air on Monday, we have baked the machine
at 80 to 120 C for approximately 24 hours while running ECDC in D2.
It will not be clear until we make discharges how well we have done in
recovery.

As a test of recovery I suggest the following (probably to be modified
depending on RGA and other indicators tomorrow morning):

. produce three or four fiducial discharges in D2

. monitior h/(h+d) and determine where we are in the cleanup

. continue antenna conditioning in helium if h/(h+d) is low

. move to MP#412a if h/(h+d) is high (Improved hydrogen-to-deuterium
changeover using radiative terminations and disruptions

Session Leader Summaries
Entered: Jun 8 2005 05:10:19:857PM
Author: Steve Wukitch
Run Summary

Recovery from the vent was fairly painless and the antenna
conditioning was not adversely affected. We verified antenna
performance in USN was still better than LSN. Initial He discharges
had significant D2 and D2 was slow to decrease compared to 1031210.
Preliminary indication is that D and E antenna operation is
improving in He. Recommend ECDC in He to reduce the D before
tomorrow's run and continue.

Physics Operator Summaries
Entered: Jun 8 2005 05:17:49:107PM
Author: Jim Irby
After the vent to air on Monday it was very good to see h/(h+d) at the
4 to 6% level for the first few discharges today. The levels did
increase as we brought up the rf, but we should be back to pre-vent
levels soon (tomorrow?). Operator error caused us to lose over an
hour today when I brought up a second instance of PCS and screwed up
the PCS files. Josh was able to fix the problem. We also had initial
startup problems probably because the machine was still cooling down
from yesterday's bake (a dud). We had difficulty maintaining
alignment on the TCI system for the same reason.

We did succeed in getting a couple of upper nulls discharges done, and
several with mostly helium. h/(h+d) remained at 7 or 8% during the
helium discharges indicating a lot of d2 was still around. The upper
null cases were pretty disruptive and indicated some cleanup was
probably required, but the SL did not want to continue that process
and we returned to SNL.

A tygon tube blew up in the DNB cabinet and caused us to lose another
45 minutes. Tubing was not reinforced tygon and the water temperature
was not low. The long period with the gatevalves closed and the
turbos not running resulted in the only fizzle of the day.

Session Leader Comments
Jun 8 2005 09:16:45:683AM1050608001Steve Wukitch001 Ip~1 MA, BT~5.4 T, fiducial
result: dud
Jun 8 2005 09:31:00:403AM1050608002Steve Wukitch002 Ip~1 MA, BT~5.4 T, fiducial
result: plasma 2 ohmic H-modes
Jun 8 2005 10:40:30:263AM1050608003Steve Wukitch003 no power shot
Jun 8 2005 10:58:21:420AM1050608004Steve Wukitch004 Ip~1 MA, BT~5.4 T, fiducial
D: 0.3 MW [.5,1.7]sec
E: 0.75 MW [0.5,1.5]sec
J: 1.5 MW [0.5,1.4]sec
result: plasma
D: ran multiple faults
E: ran multiple faults
J: ran until pressure limit

Jun 8 2005 10:58:33:030AM1050608005Steve Wukitch005 Ip~1 MA, BT~5.4 T, fiducial
D: 0.3 MW [.5,1.7]sec
E: 0.75 MW [0.5,1.5]sec
J: 1.5 MW [0.5,1.4]sec
result: plasma
D: ran multiple faults - improved
E: ran 7 faults
J: ran 3 faults

Jun 8 2005 11:32:56:403AM1050608006Steve Wukitch006 Ip~1 MA, BT~5.4 T, fiducial
D: 0.3 MW [.5,1.7]sec
E: 0.75 MW [0.5,1.5]sec
J: 1.5 MW [0.5,1.4]sec
result: plasma
D: ran multiple faults - improved
E: ran 10 faults
J: ran 1 fault

Jun 8 2005 11:53:36:480AM1050608007Steve Wukitch007 Ip~1 MA, BT~5.4 T, fiducial
D: 0.3 MW [.5,1.7]sec
E: 0.75 MW [0.5,1.5]sec
J: 2 MW [0.5,1.4]sec
result: plasma
D: ran multiple faults
E: ran 7 faults
J: ran 8 fault

Jun 8 2005 12:08:53:420PM1050608008Steve Wukitch008 Ip~1 MA, BT~5.4 T, fiducial
D: 0.3 MW [.5,1.7]sec
E: 0.75 MW [0.5,1.5]sec
J: 2 MW [0.5,1.4]sec
result: plasma
D: ran multiple faults - improved around 1.5 sec
E: ran 8 faults
J: ran 3 faults


Jun 8 2005 12:51:11:480PM1050608009Steve Wukitch009 Ip~1 MA, BT~5.4 T, fiducial, USN
dud

Jun 8 2005 03:16:44:340PM1050608009Steve Wukitch009 Ip~1 MA, BT~5.4 T, fiducial, USN
dud

Jun 8 2005 03:15:59:373PM1050608010Steve Wukitch010 no power test
Jun 8 2005 03:15:46:153PM1050608011Steve Wukitch011 no power test
Jun 8 2005 03:15:33:683PM1050608012Steve Wukitch012 Ip~1 MA, BT~5.4 T, fiducial, LSN
D: 0.3 MW [.5,1.7]sec
E: 0.75 MW [0.5,1.5]sec
J: 2.5 MW [0.5,1.4]sec
result: plasma
D: ran much improved
E: ran 3 faults
J: ran 11 faults

Jun 8 2005 03:15:17:717PM1050608013Steve Wukitch013 Ip~1 MA, BT~5.4 T, fiducial, USN
D: 0.3 MW [.5,1.7]sec
E: 0.75 MW [0.5,1.5]sec
J: 2.5 MW [0.5,1.4]sec
result: plasma
D: ran much improved
E: ran 3 faults
J: ran 11 faults

Jun 8 2005 03:15:06:810PM1050608014Steve Wukitch014 Ip~1 MA, BT~5.4 T, fiducial, USN
D: 0.5 MW [.5,1.7]sec
E: 0.75 MW [0.5,1.5]sec
J: 2 MW [0.5,1.4]sec
result: plasma
D: ran much improved
E: ran 3 faults
J: ran 1 fault

Jun 8 2005 03:14:53:013PM1050608015Steve Wukitch015 Ip~1 MA, BT~5.4 T, fiducial, USN, He plasma
D: 0.5 MW [.5,1.7]sec
E: 0.75 MW [0.5,1.5]sec
J: 2 MW [0.5,1.4]sec
result: plasma early disruption
D: ran improved
E: ran
J: ran

Jun 8 2005 03:42:03:310PM1050608017Steve Wukitch017 Ip~1 MA, BT~5.4 T, fiducial, USN, He plasma
D: 0.5 MW [.5,1.7]sec
E: 1 MW [0.5,1.5]sec
J: 1.8 MW [0.5,1.4]sec
result: plasma early disruption
D: ran 5 faults
E: ran 1 fault
J: ran
revert to LSN


Jun 8 2005 04:35:59:607PM1050608019Steve Wukitch019 Ip~1 MA, BT~5.4 T, fiducial, LSN, He plasma
result: fizzle


Jun 8 2005 04:52:24:293PM1050608020Steve Wukitch020 Ip~1 MA, BT~5.4 T, fiducial, LSN, He plasma
D: 0.5 MW [.5,1.7]sec
E: 1 MW [0.5,1.5]sec
J: 1.8 MW [0.5,1.4]sec
result: plasma
D: ran max faults improving
E: ran multiple faults but improving
J: ran 4 faults

Jun 8 2005 05:09:13:810PM1050608021Steve Wukitch021 Ip~1 MA, BT~5.4 T, fiducial, LSN, He plasma
D: 0.5 MW [.5,1.7]sec
E: 1 MW [0.5,1.5]sec
J: 1.8 MW [0.5,1.4]sec
result: plasma
D: ran max faults
E: ran multiple faults but improving
J: ran 1 faults

Physics Operator Comments
Jun 8 2005 09:44:44:013AM1050608001Jim IrbyWill not modify either seg 1 or seg 2 from shot 28 on 1050603. Both look good for today's run (1050603 was started from 1050526026, 5.4 T, 1 MA, SNL, fiducial).

prepuff will be left at 28 ms from shot 28 on 1050603.

Note that h/(h+d) was 0.04 to 0.045 on Friday

Mass3/Mass4 is 0.007 this morning on the old RGA (RGA not RGA-1). This ratio was about 0.005 before the vent to air. Not too bad.

Dud!

Bz0 is 4 mT low at 6 ms

Br0 okay

Pressure looks okay




Jun 8 2005 09:44:22:120AM1050608002Jim Irbyincreased prepuff to 32 ms from 28 ms

increased ef4 from -1320 to -1300 A

plasma into rampdown

Breakdown very late --- we were lucky

Fields looking a little better

A couple of little h-modes early and more during rampdown

Lost CO2 fringes on TCI --- only nl03, 06, and 07 are okay
HeNe 3 and 4 are having problems

opening cell to check TCI


Jun 8 2005 10:20:45:590AM1050608003Jim Irbyno pcs changes

running a cycle test to double check TF scanner

still looks like we have a problem with the scanner relay
Jun 8 2005 10:53:47:607AM1050608004Jim Irbydelay to check EF4 resistance measurement

EF4 look okay now --- cleaned Ross relay contacts

plasma into rampdown

current rise a little slow --- gas pressure high

h/(h+d) at 4 to 5% --- okay!

lots of h-modes --- 2-3 MW of rf


Jun 8 2005 11:15:08:310AM1050608005Jim Irbyreduced prefill from 32 to 30 ms

plasma into rampdown

Matt has been measuring a large amount of helium he thinks, but we can't find any valve or source for it.

115 kJ

opening cell one more time so Brock can get LPI ready to go
Jun 8 2005 11:40:55:733AM1050608006Jim Irbyno PCS changes

plasma

breakdown late again

pellet induced disruption at 1.56 --- pellet caught on wide 1

Jun 8 2005 12:04:48:683PM1050608007Jim Irbyenabled argon for John: 50 ms at 1 psi

prepuff reduced from 30 to 28 ms --- disruption, also late breakdown issues

plasma into rampdown --- pellet at 1.65 s

h/(h+d) 6.5%

3 MW and 125 kJ
Jun 8 2005 12:13:25:903PM1050608008Jim Irbyef4 from -1300 to -1280 A

prepuff from 28 to 26 ms

plasma into rampdown

Bz0 very good and gas lower but still late breakdown

no pellet
Jun 8 2005 12:35:39:827PM1050608009Jim Irbyimported seg 4 from 1050526036 into seg 3 (upper null at 1 MA)

adjusted density to 8e19 / m^2

copied over Argon puff from seg 2

disabled seg 2
enabled set 3

after all that I didn't load it...

DuD

gas low, fields good


Jun 8 2005 01:07:51:327PM1050608010Jim Irbyprepuff to 28 ms from 26 ms

looked like seg 1 was somehow modified in previous shot!!

loaded 1050608008 into seg 1

hope this will be upper null at 1 MA (seg 4 from 1050526036)

machine went to 30 mTorr D2

TCI gatevalves were shut before the shot

power supplies clearly not following programming


Jun 8 2005 01:38:58:530PM1050608011Jim Irbyreloaded shot 1050608008

no power test --- see what else goes wrong before we have power

lots of gas again --- machine gatevalves close

ratiomatic turned off well before digitizer starts indicating high pressue very early --- vessel ended up at 30 mTorr again.

cell and power room open until we figure out DPCS problem
Jun 8 2005 02:25:39:293PM1050608012Jim IrbyMost likely reason for the problem was that I had two instances of PCS running briefly and I corrupted the file structure.

We have deleted the files and restarted PCS, and reloaded shot 008 (SNL, 1 MA)

plasma into rampdown

breakdown good, fields good

problems with TCI again -- warmup in cell


Jun 8 2005 02:42:48:730PM1050608013Jim IrbyLoaded seg 4 from 1050526036 into seg 3
enabled seg 3
disabled seg 2

nl_04 request to 8e19 / m^2

plasma into rampdown --- good upper null

TCI requires cell access

fields good, breakdown good

h/(h+d) around 10%

3.5 MW and 154 kJ

pellet at 1.65 s
Jun 8 2005 03:04:21:840PM1050608014Jim Irbyno pcs changes

plasma into rampdown

lots of early x-rays
Jun 8 2005 03:23:37:090PM1050608015Jim Irby30 psi of helium in b-main

disruption at 0.855 s --- injection


Jun 8 2005 03:27:39:980PM1050608016Jim Irbyno pcs changes

plasma for .26 s --- lots of hards
Jun 8 2005 03:39:29:200PM1050608017Jim Irbyincreased preprogrammed gas before 100 ms (which is now helium)

cured hards problem but still lost plasam around 0.8 s

going lower null next shot

startup very good


Jun 8 2005 04:04:14:513PM1050608018Jim Irbydisabled seg 3
enabled seg 2 --- SNL at 1 MA

plasma into rampdown

good startup

lots of hards again --- at least as bad as earlier pre-boronization period of run campaign

h/(h+d) at 7 to 8%


Jun 8 2005 04:44:09:793PM1050608019Jim Irby42 minute delay to fix water leak in DNB cabinet --- busted tygon tube

started preprogrammed gas at 2 ms

fizzle --- probably because gatevalves were shut until we got water back to the turbo pumps

extremely late breakdown --- 14 ms

fields okay


Jun 8 2005 04:59:30:030PM1050608020Jim Irbyincreased early preprogrammed gas again
no other DPCS changes

good shot

h/(h+d) still at 8%

hards much better for some reason --- can't really claim it was the gas change


Jun 8 2005 05:13:58:030PM1050608021Jim Irbyno DPCS changes

plasma into rampdown

startup looks good

hards okay --- did get some gas in around 2 ms

h/(h+d) 8%


Engineering Operator Comments
ShotTimeTypeStatusComment
109:03:41:497AMPlasmaOk
209:27:37:247AMPlasmaOk
310:02:54:870AMTestOk
410:36:10:810AMPlasmaOk
510:52:13:920AMPlasmaOk
611:19:31:967AMPlasmaOk
711:39:28:827AMPlasmaOk
811:59:28:827AMPlasmaOk
912:29:39:280PMPlasmaOk
1012:47:57:263PMPlasmaOk
1101:10:53:887PMPlasmaBadLow Brid Problem
1202:12:15:120PMPlasmaOk
1302:30:13:013PMPlasmaOk
1402:48:31:497PMPlasmaOk
1503:07:12:933PMPlasmaOk
1603:21:07:293PMPlasmaOk
1703:33:59:403PMPlasmaOk
1803:46:46:060PMPlasmaOk
1904:32:13:043PMPlasmaOk
2004:44:50:560PMPlasmaOk
2104:58:13:730PMPlasmaOk