Alcator C-Mod Run 1020808 Information

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Miniproposals
Miniproposal:
Date Filed:
Title:
First Author:
Session Leader:Steve Wukitch (shots 1-25)
Session Leader:Yijun Lin (shots 1-25)

Operators
Session leader(s):Steve Wukitch,Yijun Lin
Physics operator(s):Dmitri Mossessian
Engineering operator(s):Bill Parkin,Bill Byford

Engineering Operator Run Comment
RF Conditioning; SL: S. Wukitch, Y. Lin; PO: D. Mossessian; EO: Byford/P

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:29:710PM
Author: To Be Determined
Engineering setup for Thursday 08 Aug 2002

Session leader: S. Wukitch, Y. Lin
Physics operator: D. Mossessian

ECDC in the morning, if possible, stopping by 07:00.
Set up for possible ECDC in D2 between shots.

Run begins at 11:00 and ends at 17:00.

We need to modify and test the J-port arc protection before plasma operation can
begin. Furthermore, we wish to vacuum condition all antennas to examine the gas
evolution during vacuum conditioning.

For the beginning of plasma operation, set up power systems as on 1020806013,
which was a limited plasma (for the RF...no H-modes)

Note:
The RF will be firing into vacuum before the run begins, so we will want to
do 10 minutes of ECDC just before the first plasma shot.

Gas setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar Hybrid enabled (PG1)
fill B-side upper with 10 psi D2 Hybrid DISABLED (PG2) (for ECDC)
fill C-side with 30 psi D2 Hybrid enabled (PG3)
leave J-Bottom as is Hybrid DISABLED (PG5)

Enable the following gate valves, assuming no vacuum problems:
ECE, VUV, DNB

-------------------------------------------------------------------------------
RF Setup: FMIT#1&2 transmitters in Run On by 07:00.
FMIT#3&4 transmitters in Run On by 09:30.

-------------------------------------------------------------------------------
Run Plan:

Work on D, E, and J systems into plasma.

Start by loading segment 2 from 1020806013 (limiter plasma)and let the RF
go at it. We may switch to a diverted shot later in the day (use segment 2
from 1020802021)

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

001

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.2 MW ramp @[1.2-1.5]sec
E: 1.2 MW ramp @[1.2-1.5]sec
J: 0.6 MW ramp @[0.6-1.5]sec

result: fizzle

002

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.2 MW ramp @[1.2-1.5]sec
E: 1.2 MW ramp @[1.2-1.5]sec
J: 0.6 MW ramp @[0.6-1.5]sec

result: fizzle

003

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.2 MW ramp @[1.2-1.5]sec
E: 1.2 MW ramp @[1.2-1.5]sec
J: 0.6 MW ramp @[0.6-1.5]sec

result: plasma
D: 1.2 MW good
E: 1.2 MW good
J: 0.6 MW initially ramped but failed on retries (all phase
balance faults)

action:
raise D and E by 100 kW each
retune J and raise phase balance power threshold from 6.9 V to
7.5 V

004

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.3 MW ramp @[1.2-1.5]sec
E: 1.3 MW ramp @[1.2-1.5]sec
J: 0.6 MW ramp @[0.6-1.5]sec

result: plasma
D: 1.3 MW good
E: 1.3 MW good
J: 0.6 MW (only two faults - phase balance but fast data
indicate the reflected power was increasing rapidly suggesting an arc
was more sensitively detected by the phase balance circuit)

First time the three had run together this campaign

action: raise power by 0.1 MW on D and E
raise power by 0.2 MW on J

005

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.4 MW ramp @[1.2-1.5]sec
E: 1.4 MW ramp @[1.2-1.5]sec
J: 0.8 MW ramp @[0.6-1.5]sec

result: plasma
D: 1.4 MW good
E: 1.4 MW good
J: 0.8 MW several faults - looks like arcing

action: raise D and E to 1.5 MW

006

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.5 MW ramp @[1.2-1.5]sec
E: 1.5 MW ramp @[1.2-1.5]sec
J: 0.8 MW ramp @[0.6-1.5]sec

result: plasma
D: 1.5 MW good
E: 1.5 MW good
J: 0.8 MW several faults - looks like arcing

action: increase width of D and E-port pulse

007

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.5 MW ramp @[1.2-1.5]sec
E: 1.5 MW ramp @[1.2-1.5]sec
J: 0.8 MW ramp @[0.6-1.5]sec

result: fizzle

increase pedestal level from 0.6 V to 1.0 V

008

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.5 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 0.8 MW ramp @[0.6-1.5]sec

result: plasma
D: 1.5 MW faulted and failed on the retries due to phase balance
E: 1.5 MW good
J: 0.8 MW faulted - pedestal was above arc power threshold ->
arc indication before the sources have phase locked.

action: raise D phase balance to 2.0 V from 1.162 V
lower pedestal level from 1.0 V to 0.8 V

009

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.5 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 0.8 MW ramp @[0.6-1.5]sec

result: plasma
D: 1.5 MW faulted and failed on the retries due to phase balance
E: 1.5 MW good
J: 0.8 MW faulted but retries were better
action: lower power on D-port

010

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.2 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 0.8 MW ramp @[0.6-1.5]sec

result: fizzle

011

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.2 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 0.8 MW ramp @[0.6-1.5]sec

result: plasma
D: 1.2 MW good
E: 1.5 MW good
J: 0.8 MW faulted - more phase lock problems

012

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.3 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 0.8 MW ramp @[0.6-1.5]sec

result: fizzle

013

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.3 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 0.8 MW ramp @[0.6-1.5]sec

result: plasma
D: 1.3 MW two faults
E: 1.5 MW good
J: 0.8 MW better
action: raise J to 1 MW

014

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.3 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 0.8 MW ramp @[0.6-1.5]sec

result: fizzle

015

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.2 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 1.0 MW ramp @[0.6-1.5]sec

result: plasma
D: 1.2 MW faulted off
E: 1.5 MW good
J: 1.0 MW faults
action: raise J to 1.2 MW

016

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.1 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 1.2 MW ramp @[0.6-1.5]sec

result: plasma
D: 1.1 MW good
E: 1.5 MW good
J: 1.2 MW reasonable

017

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.2 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 1.4 MW ramp @[0.6-1.5]sec

result: fizzle

018

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.2 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 1.4 MW ramp @[0.6-1.5]sec

result: plasma
D: 1.2 MW good
E: 1.5 MW good
J: 1.4 MW reasonable
019

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.2 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 1.6 MW ramp @[0.6-1.5]sec

result: plasma
D: 1.2 MW good
E: 1.5 MW good
J: 1.4 MW multiple faults
action: lower field to 5 T

020

request: inner wall limited Ip~0.8 MA, BT~5.0 T, nl_04~1x10^20 m^-2
D: 1.4 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 1.6 MW ramp @[0.6-1.5]sec

result: fizzle

021

request: inner wall limited Ip~0.8 MA, BT~5.0 T, nl_04~1x10^20 m^-2
D: 1.4 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 1.6 MW ramp @[0.6-1.5]sec

result: plasma
D: 1.4 MW faulted
E: 1.5 MW good
J: 1.4 MW multiple faults
action: lower field to 4.6 T

022

request: inner wall limited Ip~0.8 MA, BT~4.6 T, nl_04~1x10^20 m^-2
D: off
E: off
J: 1.6 MW ramp @[0.6-1.5]sec
result: plasma
J: 1.8 MW multiple faults - arcs

023

request: inner wall limited Ip~0.8 MA, BT~4.6 T, nl_04~1x10^20 m^-2
D: off
E: off
J: 1.8 MW ramp @[0.6-1.5]sec
result: dud

024

request: inner wall limited Ip~0.8 MA, BT~4.6 T, nl_04~1x10^20 m^-2
D: off
E: off
J: 1.8 MW ramp @[0.6-1.5]sec
result: dud

025

request: inner wall limited Ip~0.8 MA, BT~4.6 T, nl_04~1x10^20 m^-2
D: off
E: off
J: 1.8 MW ramp @[0.6-1.5]sec
result: fizzle


Summary:

Since the previous run on Tuesday, we have modified the J-port DC1 arc
detector modules. (On Tuesday we had a false arc indication from
J3DC1 and we have had continual problems with the phase balance power
threshold. Changing to the new demodulators should remedy these
problems.) After changing these units, we did vacuum conditioning on
all three antennas. When we finished, the pressure rise associated
with D and E was below detection limits but J-port was indicating a
measureable gas puff. Each antenna was reconditioned to ~35 kV and
the process was much easier than it has been in the recent past.

We examined the B-dot data from [0,0,0,0] and [0,pi,0,pi] vacuum
shots. With [0,0,0,0] phasing the STOP and SBOT show similar signal
levels (low as expected). For [0,pi,0,pi] phasing, the STOP has
little signal and SBOT is very large (larger than expected). We will
perform a time domain test on the probes to verify their functioning
state. If the probes are in fact working, we will need more testing
to confirm these observations and some modeling to understand the
measurements.

Operation into plasma was improved for all antennas. The maximum
injected power was ~3.8 MW (1.5 MW from D and E-port and 0.8 MW from
J-port)[1020808006]. After obtaining 1.5 MW on D and E, we
concentrated on J-port and lowered the toroidal field to 4.6 T. We
obtained 1.8 MW for ~0.1 sec from J-port. We also confirmed the
improved J-port arc detection functioned properly and that the phase
feedback appears to require 15 msec to lock. J-port appears to
require more conditioning to become functional for physics operations.

Physics Operator Summaries
Entered: Jul 7 2004 04:37:15:600PM
Author: To Be Determined
Physop summary for Thursday, August 08, 2002

==============================================================
The plan:

Engineering setup for Thursday 08 Aug 2002

Session leader: S. Wukitch, Y. Lin
Physics operator: D. Mossessian

ECDC in the morning, if possible, stopping by 07:00.
Set up for possible ECDC in D2 between shots.

Run begins at 11:00 and ends at 17:00.

We need to modify and test the J-port arc protection before plasma operation can
begin. Furthermore, we wish to vacuum condition all antennas to examine the gas
evolution during vacuum conditioning.

For the beginning of plasma operation, set up power systems as on 1020806013,
which was a limited plasma (for the RF...no H-modes)

Note:
The RF will be firing into vacuum before the run begins, so we will want to
do 10 minutes of ECDC just before the first plasma shot.

Gas setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar Hybrid enabled (PG1)
fill B-side upper with 10 psi D2 Hybrid DISABLED (PG2) (for ECDC)
fill C-side with 30 psi D2 Hybrid enabled (PG3)
leave J-Bottom as is Hybrid DISABLED (PG5)

Enable the following gate valves, assuming no vacuum problems:
ECE, VUV, DNB

-------------------------------------------------------------------------------
RF Setup: FMIT#1&2 transmitters in Run On by 07:00.
FMIT#3&4 transmitters in Run On by 09:30.

-------------------------------------------------------------------------------
Run Plan:

Work on D, E, and J systems into plasma.

Start by loading segment 2 from 1020806013 (limiter plasma)and let the RF
go at it. We may switch to a diverted shot later in the day (use segment 2
from 1020802021)

======================================================================

Summary:

The run started at 11:15 and continued to 17:00 with variabe succes. The main problem was
unreliable startup. For some reason Br was oscillating at the startup phase, although
it is not clear whether it was the reason for multiple fizzles we had. Generally, by playing with
fileds we were able to get every second shot to develop a plasma. Moving the downward step
in Br gain farther into the shot (to 0.025 s) at shot 20 seem to help somewhat. Then at 16:30
we had a dud for no apparent reason. Another dud followed and adding Argon to startup phase
(following S. Wolfe's advise) produced a fizzle with very late breakdown on the las shot.

On shot 20 the field 3was changed to 5T at RF's request, on shot 22 it was dropped further to 4.6 T

25 shots
9 fizzles
2 duds
14 plasmas

=========================================================================

Details:


1020808001

Fizzle. late breakdown (0.01 s), virtually no current rise. The fields look the same as on good shots.

For next shot - drop prepuff 0.025 s -> 0.023 s
-----------------------------------------------------------------------------
1020808002

Fizzle. A little faster current rise and a little more current. Still late breakdown

For next shot - less gas: pulse_gas4 23 -> 21 ms; Bz up: IC_EF4 -1330 -> -1310
-----------------------------------------------------------------------------
1020808003

PLasma. The breakdown is still late (0.008 s) , the current rise after that is OK.

For next shot - drop prepuff from 21 ms to 19 ms.
-----------------------------------------------------------------------------
1020808004

PLasma. Still late breakdown.

For next shot - Bz up alittle : IC_EF4 -1310 -> -1305
-----------------------------------------------------------------------------
1020808005 mossessian PHYSICS_OPERATOR Aug 8 2002 12:31:53:266PM
. . . . . . . . . . . . . . . . . . . .
PLasma. Breakdown time does not change

For next shot - no changes.
-----------------------------------------------------------------------------
1020808006 mossessian PHYSICS_OPERATOR Aug 8 2002 12:32:29:296PM
. . . . . . . . . . . . . . . . . . . .
Plasma.
For next shot - no changes.
-----------------------------------------------------------------------------
1020808007 mossessian PHYSICS_OPERATOR Aug 8 2002 1:13:10:593PM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Large excursion of Br between 0.01 and 0.02 s causes the untimely death of the plasma.

For next shot - no PCS changes.
-----------------------------------------------------------------------------
1020808008 mossessian PHYSICS_OPERATOR Aug 8 2002 1:13:21:313PM
. . . . . . . . . . . . . . . . . . . .
Plasma
For next shot - no PCS changes.
-----------------------------------------------------------------------------
1020808009 mossessian PHYSICS_OPERATOR Aug 8 2002 1:20:03:643PM
. . . . . . . . . . . . . . . . . . . .
Plasma
For next shot - no PCS changes.
-----------------------------------------------------------------------------
1020808010 mossessian PHYSICS_OPERATOR Aug 8 2002 1:47:40:483PM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Oscillations in Br again.
For next shot - no PCS changes.
-----------------------------------------------------------------------------
1020808011 mossessian PHYSICS_OPERATOR Aug 8 2002 1:55:43:813PM
. . . . . . . . . . . . . . . . . . . .
Plasma

For next shot - no PCS changes.
-----------------------------------------------------------------------------
1020808012 mossessian PHYSICS_OPERATOR Aug 8 2002 2:10:59:976PM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Br still oscillates. However, Steve suggests that too positive Bz cayses our problems.

For next shot -try making Bz more negative. IC_EF4 -1305 -> -1315
-----------------------------------------------------------------------------
1020808013 mossessian PHYSICS_OPERATOR Aug 8 2002 2:32:16:610PM
. . . . . . . . . . . . . . . . . . . .
plasma

For next shot - no PCS changes
-----------------------------------------------------------------------------
1020808014 mossessian PHYSICS_OPERATOR Aug 8 2002 2:35:09:923PM
. . . . . . . . . . . . . . . . . . . .
Fizzle - Bz too low.

For next shot - IC_EF4 -1305 -> -1300
-----------------------------------------------------------------------------
1020808015 mossessian PHYSICS_OPERATOR Aug 8 2002 2:49:58:520PM
. . . . . . . . . . . . . . . . . . . .
Plasma

For next shot - no changes
-----------------------------------------------------------------------------
1020808016 mossessian PHYSICS_OPERATOR Aug 8 2002 3:00:31:886PM
. . . . . . . . . . . . . . . . . . . .
Plasma. No fields data available, so we will not change anything.

For next shot - no changes
-----------------------------------------------------------------------------
1020808017 mossessian PHYSICS_OPERATOR Aug 8 2002 3:15:12:016PM
. . . . . . . . . . . . . . . . . . . .
Fizzle. No fields data available the ques on CLARET are stalled. Let's guess:

For next shot - IC_EF4 -1300 -> -1310
-----------------------------------------------------------------------------
1020808019 mossessian PHYSICS_OPERATOR Aug 8 2002 3:40:37:586PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

Next shot - no changes.
-----------------------------------------------------------------------------
1020808018 mossessian PHYSICS_OPERATOR Aug 8 2002 3:40:49:980PM
. . . . . . . . . . . . . . . . . . . .
Plasma.

Next shot - no changes.
-----------------------------------------------------------------------------
1020808020 mossessian PHYSICS_OPERATOR Aug 8 2002 4:05:51:130PM
. . . . . . . . . . . . . . . . . . . .
At RF's request the field was changed to 5 T. TF current 150000 -> 141000

Fizzle. Bz a little too high. Br oscillates

For next shot - Bz: IC_EF4 -1310 -> -1315; moved downward step in Br gain from 0.01 to 0.025 s
-----------------------------------------------------------------------------
1020808021 mossessian PHYSICS_OPERATOR Aug 8 2002 4:16:02:243PM
. . . . . . . . . . . . . . . . . . . .
PLasma. 5.0 T. Br does not oscillate.

For next shot - TF current down 141000 -> 131000 for 4.6 T
-----------------------------------------------------------------------------
1020808022 mossessian PHYSICS_OPERATOR Aug 8 2002 4:35:46:530PM
. . . . . . . . . . . . . . . . . . . .
PLasma. 4.7 T.

For next shot - no changes
-----------------------------------------------------------------------------
1020808023 mossessian PHYSICS_OPERATOR Aug 8 2002 4:44:17:486PM
. . . . . . . . . . . . . . . . . . . .
Dud. No apparent reason.

Next shot - Bz up a little: -1315 -> -1310
-----------------------------------------------------------------------------
1020808024 mossessian PHYSICS_OPERATOR Aug 8 2002 4:54:05:350PM
. . . . . . . . . . . . . . . . . . . .
Dud.

For next shot - Set Argon pulse in startup segment - copied trace from
pulse_gas4 (prepuff) into pulse_gas1 (Ar)
-----------------------------------------------------------------------------
1020808025 mossessian PHYSICS_OPERATOR Aug 8 2002 5:00:44:120PM
. . . . . . . . . . . . . . . . . . . .
Fizzle. Very late breakdown.
-

Session Leader Comments
Aug 8 2002 11:21:45:537AM1020808001Steve Wukitch001

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.2 MW ramp @[1.2-1.5]sec
E: 1.2 MW ramp @[1.2-1.5]sec
J: 0.6 MW ramp @[0.6-1.5]sec

result: fizzle
Aug 8 2002 11:50:39:873AM1020808002Steve Wukitch002

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.2 MW ramp @[1.2-1.5]sec
E: 1.2 MW ramp @[1.2-1.5]sec
J: 0.6 MW ramp @[0.6-1.5]sec

result: fizzle
Aug 8 2002 12:04:54:380PM1020808003Steve Wukitch003

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.2 MW ramp @[1.2-1.5]sec
E: 1.2 MW ramp @[1.2-1.5]sec
J: 0.6 MW ramp @[0.6-1.5]sec

result: plasma
D: 1.2 MW good
E: 1.2 MW good
J: 0.6 MW initially ramped but failed on retries (all phase
balance faults)

action:
raise D and E by 100 kW each
retune J and raise phase balance power threshold from 6.9 V to
8.0 V
Aug 8 2002 12:14:40:040PM1020808004Steve Wukitch004

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.3 MW ramp @[1.2-1.5]sec
E: 1.3 MW ramp @[1.2-1.5]sec
J: 0.6 MW ramp @[0.6-1.5]sec

result: plasma
D: 1.3 MW good
E: 1.3 MW good
J: 0.6 MW (only two faults - phase balance but fast data
indicate the reflected power was increasing rapidly suggesting an arc
was more sensitively detected by the phase balance circuit)

First time the three had run together this campaign

action: raise power by 0.1 MW on D and E
raise power by 0.2 MW on J
Aug 8 2002 12:23:11:497PM1020808005Steve Wukitch005

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.4 MW ramp @[1.2-1.5]sec
E: 1.4 MW ramp @[1.2-1.5]sec
J: 0.8 MW ramp @[0.6-1.5]sec

result: plasma
D: 1.4 MW good
E: 1.4 MW good
J: 0.8 MW several faults - looks like arcing

action: raise D and E to 1.5 MW
Aug 8 2002 12:41:34:490PM1020808006Steve Wukitch006

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.5 MW ramp @[1.2-1.5]sec
E: 1.5 MW ramp @[1.2-1.5]sec
J: 0.8 MW ramp @[0.6-1.5]sec

result: plasma
D: 1.5 MW good
E: 1.5 MW good
J: 0.8 MW several faults - looks like arcing

action: increase width of D and E-port pulse
Aug 8 2002 12:48:54:897PM1020808007Steve Wukitch007

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.5 MW ramp @[1.2-1.5]sec
E: 1.5 MW ramp @[1.2-1.5]sec
J: 0.8 MW ramp @[0.6-1.5]sec

result: fizzle
Aug 8 2002 01:18:37:707PM1020808008Steve Wukitch008

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.5 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 0.8 MW ramp @[0.6-1.5]sec

result: plasma
D: 1.5 MW faulted and failed on the retries due to phase balance
E: 1.5 MW good
J: 0.8 MW faulted - pedestal was above arc power threshold ->
arc indication before the sources have phase locked.

action: raise D phase balance to 2.0 V from 1.162 V
lower pedestal level from 1.0 V to 0.8 V
Aug 8 2002 01:34:20:947PM1020808009Steve Wukitch009

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.5 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 0.8 MW ramp @[0.6-1.5]sec

result: plasma
D: 1.5 MW faulted and failed on the retries due to phase balance
E: 1.5 MW good
J: 0.8 MW faulted but retries were better
action: lower power on D-port
Aug 8 2002 01:34:50:260PM1020808010Steve Wukitch010

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.2 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 0.8 MW ramp @[0.6-1.5]sec

result: fizzle
Aug 8 2002 02:03:09:800PM1020808011Steve Wukitch011

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.2 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 0.8 MW ramp @[0.6-1.5]sec

result: plasma
D: 1.2 MW good
E: 1.5 MW good
J: 0.8 MW faulted - more phase lock problems
Aug 8 2002 02:03:24:550PM1020808012Steve Wukitch012

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.3 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 0.8 MW ramp @[0.6-1.5]sec

result: fizzle
Aug 8 2002 02:37:47:580PM1020808014Steve Wukitch014

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.3 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 0.8 MW ramp @[0.6-1.5]sec

result: fizzle
Aug 8 2002 02:42:28:490PM1020808015Steve Wukitch015

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.2 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 0.8 MW ramp @[0.6-1.5]sec

result: plasma
D: 1.2 MW faulted off
E: 1.5 MW good
J: 1.0 MW still faults
action: raise J to 1.2 MW
Aug 8 2002 03:16:18:030PM1020808016Steve Wukitch016

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.1 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 1.2 MW ramp @[0.6-1.5]sec

result: plasma
D: 1.1 MW good
E: 1.5 MW good
J: 1.2 MW reasonable
Aug 8 2002 03:16:53:923PM1020808017Steve Wukitch017

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.2 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 1.4 MW ramp @[0.6-1.5]sec

result: fizzle
Aug 8 2002 03:26:32:613PM1020808018Steve Wukitch018

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.2 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 1.4 MW ramp @[0.6-1.5]sec

result: plasma
D: 1.2 MW good
E: 1.5 MW good
J: 1.4 MW reasonable
Aug 8 2002 04:06:11:317PM1020808019Steve Wukitch019

request: inner wall limited Ip~0.8 MA, BT~5.4 T, nl_04~1x10^20 m^-2
D: 1.2 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 1.6 MW ramp @[0.6-1.5]sec

result: plasma
D: 1.2 MW good
E: 1.5 MW good
J: 1.4 MW multiple faults
action: lower field to 5 T
Aug 8 2002 04:17:43:007PM1020808020Steve Wukitch020

request: inner wall limited Ip~0.8 MA, BT~5.0 T, nl_04~1x10^20 m^-2
D: 1.2 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 1.6 MW ramp @[0.6-1.5]sec

result: fizzle
Aug 8 2002 04:21:43:167PM1020808021Steve Wukitch021

request: inner wall limited Ip~0.8 MA, BT~5.0 T, nl_04~1x10^20 m^-2
D: 1.4 MW ramp @[1.0-1.5]sec
E: 1.5 MW ramp @[1.0-1.5]sec
J: 1.6 MW ramp @[0.6-1.5]sec

result: plasma
D: 1.4 MW faulted
E: 1.5 MW good
J: 1.4 MW multiple faults
action: lower field to 4.6 T
Aug 8 2002 04:49:10:613PM1020808022Steve Wukitch022

request: inner wall limited Ip~0.8 MA, BT~4.6 T, nl_04~1x10^20 m^-2
D: off
E: off
J: 1.6 MW ramp @[0.6-1.5]sec
result: plasma
J: 1.8 MW multiple faults - arcs
Aug 8 2002 04:49:40:257PM1020808023Steve Wukitch023

request: inner wall limited Ip~0.8 MA, BT~4.6 T, nl_04~1x10^20 m^-2
D: off
E: off
J: 1.8 MW ramp @[0.6-1.5]sec
result: dud
Aug 8 2002 04:49:57:100PM1020808024Steve Wukitch024

request: inner wall limited Ip~0.8 MA, BT~4.6 T, nl_04~1x10^20 m^-2
D: off
E: off
J: 1.8 MW ramp @[0.6-1.5]sec
result: dud

Physics Operator Comments
Aug 8 2002 11:03:51:670AMDmitri MossessianRun Plan:

Work on D, E, and J systems into plasma.

Start by loading segment 2 from 1020806013 (limiter plasma)and let the RF
go at it. We may switch to a diverted shot later in the day (use segment 2
from 1020802021)

10:55 - Loaded segment 2 from 1020806013. Segment 1 is still from 1020807035 (last shot yesterday), although
the startup does not look very good there - might want to change to a different startup later on.

Coldstart OK
Aug 8 2002 11:42:06:010AM1020808001Dmitri MossessianFizzle. late breakdown (0.01 s), virtually no current rise. The fields look the same as on good shots.

For next shot - drop prepuff 0.025 s -> 0.023 s
Aug 8 2002 11:42:35:120AM1020808002Dmitri MossessianFizzle. A little faster current rise and a little more current. Still late breakdown

For next shot - less gas: pulse_gas4 23 -> 21 ms; Bz up: IC_EF4 -1330 -> -1310
Aug 8 2002 12:31:11:000PM1020808003Dmitri MossessianPLasma. The breakdown is still late (0.008 s) , the current rise after that is OK.

For next shot - drop prepuff from 21 ms to 19 ms.
Aug 8 2002 12:31:43:373PM1020808004Dmitri MossessianPLasma. Still late breakdown.

For next shot - Bz up alittle : IC_EF4 -1310 -> -1305
Aug 8 2002 12:31:53:267PM1020808005Dmitri MossessianPLasma. Breakdown time does not change

For next shot - no changes.
Aug 8 2002 12:32:29:297PM1020808006Dmitri MossessianPlasma.
For next shot - no changes.
Aug 8 2002 01:13:10:593PM1020808007Dmitri MossessianFizzle. Large excursion of Br between 0.01 and 0.02 s causes the untimely death of the plasma.

For next shot - no PCS changes.
Aug 8 2002 01:13:21:313PM1020808008Dmitri MossessianPlasma
For next shot - no PCS changes.
Aug 8 2002 01:20:03:643PM1020808009Dmitri MossessianPlasma
For next shot - no PCS changes.
Aug 8 2002 01:47:40:483PM1020808010Dmitri MossessianFizzle. Oscillations in Br again.
For next shot - no PCS changes.
Aug 8 2002 01:55:43:813PM1020808011Dmitri MossessianPlasma

For next shot - no PCS changes.
Aug 8 2002 02:10:59:977PM1020808012Dmitri MossessianFizzle. Br still oscillates. However, Steve suggests that too positive Bz cayses our problems.

For next shot -try making Bz more negative. IC_EF4 -1305 -> -1315
Aug 8 2002 02:32:16:610PM1020808013Dmitri Mossessianplasma

For next shot - no PCS changes
Aug 8 2002 02:35:09:923PM1020808014Dmitri MossessianFizzle - Bz too low.

For next shot - IC_EF4 -1305 -> -1300
Aug 8 2002 02:49:58:520PM1020808015Dmitri MossessianPlasma

For next shot - no changes
Aug 8 2002 03:00:31:887PM1020808016Dmitri MossessianPlasma. No fields data available, so we will not change anything.

For next shot - no changes
Aug 8 2002 03:15:12:017PM1020808017Dmitri MossessianFizzle. No fields data available the ques on CLARET are stalled. Let's guess:

For next shot - IC_EF4 -1300 -> -1310
Aug 8 2002 03:40:49:980PM1020808018Dmitri MossessianPlasma.

Next shot - no changes.
Aug 8 2002 03:40:37:587PM1020808019Dmitri MossessianPlasma.

Next shot - no changes.
Aug 8 2002 04:05:51:130PM1020808020Dmitri MossessianAt RF's request the field was changed to 5 T. TF current 150000 -> 141000

Fizzle. Bz a little too high. Br oscillates

For next shot - Bz: IC_EF4 -1310 -> -1315; moved downward step in Br gain from 0.01 to 0.025 s
Aug 8 2002 04:16:02:243PM1020808021Dmitri MossessianPLasma. 5.0 T. Br does not oscillate.

For next shot - TF current down 141000 -> 131000 for 4.6 T
Aug 8 2002 04:35:46:530PM1020808022Dmitri MossessianPLasma. 4.7 T.

For next shot - no changes
Aug 8 2002 04:44:17:487PM1020808023Dmitri MossessianDud. No apparent reason.

Next shot - Bz up a little: -1315 -> -1310
Aug 8 2002 04:54:05:350PM1020808024Dmitri MossessianDud.

For next shot - Set Argon pulse in startup segment - copied trace from
pulse_gas4 (prepuff) into pulse_gas1 (Ar)
Aug 8 2002 05:00:44:120PM1020808025Dmitri MossessianFizzle. Very late breakdown.

Engineering Operator Comments
ShotTimeTypeStatusComment
111:18:45:970AMPlasmaOk
211:34:25:180AMPlasmaOk
311:47:04:497AMPlasmaOk
412:03:20:380PMPlasmaOk
512:15:48:103PMPlasmaOk
612:29:08:670PMPlasmaOk
712:42:19:770PMPlasmaOk
801:03:21:277PMPlasmaOk
901:17:06:360PMPlasmaOk
1001:32:05:383PMPlasmaOk
1101:46:04:983PMPlasmaOk
1201:58:23:347PMPlasmaOk
1302:11:58:400PMPlasmaOk
1402:24:26:760PMPlasmaOk
1502:36:59:127PMPlasmaOk
1602:52:40:397PMPlasmaOk
1703:05:57:230PMPlasmaOk
1803:20:23:393PMPlasmaOk
1903:35:43:180PMPlasmaOk
2003:55:37:017PMPlasmaOk
2104:08:21:147PMPlasmaOk
2204:21:25:870PMPlasmaOk
2304:33:52:280PMPlasmaOk
2404:46:11:427PMPlasmaOk
2504:58:36:087PMPlasmaOk