Alcator C-Mod Run 1020711 Information

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Miniproposals
Miniproposal:
Date Filed:
Title:
First Author:
Session Leader:Steve Wukitch (shots 1-10)

Operators
Session leader(s):Steve Wukitch
Physics operator(s):Robert Granetz
Engineering operator(s):Gary Dekow,Bill Cochran

Engineering Operator Run Comment
Machine Conditioning with RF; SL: Wukitch; PO: Granetz; EO: Cochran/Deko

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:29:397PM
Author: To Be Determined
Run 1020711: Machine and RF Conditioning Campaign Continued

EO: Cochran/Dekow
PO: Granetz
SL: Irby/Wolfe


After three days of work on the RAID disk system we were able to run the
machine again today. The purpose of this run was to continue conditioning
of the machine with rf power if possible.

ECDC was run almost continuously since the 7/02 run. In addition we
have baked the machine at 60C for several days.

The H/D ratio was down another 2% or so today compared to last week.
The plasma disrupted at 0.444 s on shot 06 following a disruption at 1.4 s
on shot 05. Both H/D and the carbon II were up a factor of 2 at 0.4 s
compared to shots earlier today.

Using the Granetz startup we were able to get four plasmas in a row.
We stopped early today so that rf could continue to debug their
electronics.

Duds none
Fizzles none
Plasmas 03,04,05,06
Tests 01,02

Physics Operator Summaries
Entered: Jul 7 2004 04:37:15:287PM
Author: To Be Determined
Physics operator summary for run 1020711 (Thursday):

Session leader: S. Wukitch
Physics operator: R. Granetz
Engineer in charge: G. Dekow/B. Cochran

Summary: Although the tokamak ran well, going 4 for 4 on plasma startup, the
data systems had some problems, and the RF needed more time without
plasma operation to make better progress. So we stopped the run
early to accommodate them. H/D was 8-10%. The plasma didn't like
running at higher densities, and disrupted when the gas fueling got
really strong.

Scorecard: 4 plasmas
0 fizzles
0 duds
2 tests
0 aborted and/or screwed up by computer problems
----------
6 total

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

Engineering setup for Thursday 11 July 2002

Session leader: S. Wukitch (surprise Steve!)
Physics operator: R. Granetz

ECDC overnight in D2 at 2e-4 Torr, stopping by 07:00.
Set up for possible ECDC in D2 between shots.

Run begins at 11:00 (note the delayed start) and ends at 17:00.

Power systems the same as for shot 1020702024.

Note: We'll have to start with an OH test to check out the data acquisition
system, as well as hardware changes made to the magnetics.

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:
DNB, ECE

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

Note the delayed starting time for the run. The RF will be firing into vacuum
for the first few hours of the morning before the run begins. The cell will
be open until around 11:00.

First shot will be an OH test to check the data acquisition system, as well as
hardware changes made to the magnetics.

Then load shot 1020628023 (standard SNL, 0.8 MA, 5.3 T, 1.e20 m-2) and pick
up where we left off. Over the past 2 weeks of operation, we have
developed two different startup scenarios: Ian's (segment 1 of 1020702024)
and non-Ian's. I'll start with non-Ian's, confirm its reliability, and
then perhaps switch to Ian's and compare reliabilities.

RF will probably be firing J-port into plasma, in which case we may want to
do between-shot ECDC.

-------------------------------------------------------------------------------
Overnight ECDC in D2 was done.

Hybrid coldstart done; no errors found

Loaded PCS from shot 1020628023 for segment 1 and shot 1020702024 for
segment 2, and confirmed that density feedback is turned off, per
Jim Irby's request.

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

Shot 01 -- Test. OH and EF1 only, under PLC control ... to check data system
and also magnetics hardware changes.

Next shot: we need another test the check BP15_BC, which had too
low a signal level.

Between-shot ECDC is being done now.

Shot 02 -- Test. EF3 only under PLC control. This is to check the signal
on BP15_BC, which had strangely low amplitude on shot 01.

BP15_BC looks okay (by comparison to BP15_DE).

Next shot: go for plasma.

Shot 03 -- Plasma. Good shot. 0.8 MA, 5.3 T, 0.6e20 m-2, SNL. The density
feedback signal is inverted, so Jim will fix that for the next
shot. H/D=0.09.

Next shot: turn on density feedback and increase density
to 1.e20 m-2.

Shot 04 -- Plasma. Good shot. nl_04=1.0e20 m-2, as requested. H/D=0.08-0.10.
Density feedback worked well.

Next shot: raise density to nl_04=1.2e20 m-2.

Shot 05 -- Plasma. Lots of DAQ failures...no Ip signal available. Disrupted
at 1.4 s. Mag_TR16_3 didn't receive trigger. H/D didn't go
because of the missing Ip signal.

I ran a test shot after the plasma shot and TR16_3 failed to
trigger again. Steve and I went down and unplugged/plugged in
the TR16_3 trigger cable, ran a test shot, and it's now okay.

Next shot: repeat at same density to get H/D (it needs Ip)

Shot 06 -- Plasma. Disrupted at t=0.44 s. Ip was starting to turn over, so
it may have been due to too much gas.

We're going to stop here and let the RF have the time. We're 4 for 4 on
plasma startup, using the non-IHH segment 1.

End of run.

Session Leader Comments
Jul 11 2002 12:22:34:860PM1020711003Jim IrbyPlasma

H/D 9% at 1s

nl04 feedback signal went negative --- see TCI topic

Jul 11 2002 12:34:54:943PM1020711004Jim IrbyPlasma --- asked for 1e20/m^2

H/D .086
Jul 11 2002 03:30:15:017PM1020711005Jim IrbyRequested higher density

Disrupted at 1.43 s --- probably trying too hard to get high density at 800 kA

Lost a lot of data: Ip for example

H/D 9% at 1 s



Jul 11 2002 01:59:24:410PM1020711006Jim IrbyRepeat at same nl04 request

Plasma for 0.444 s

H/D 17% at .4 s --- factor of 2 up from shot 004

Carbon II also up a factor of 2 following the disruption

Physics Operator Comments
Jul 11 2002 09:14:32:697AMRobert GranetzEngineering setup for Thursday 11 July 2002

Session leader: S. Wukitch (surprise Steve!)
Physics operator: R. Granetz

ECDC overnight in D2 at 2e-4 Torr, stopping by 07:00.
Set up for possible ECDC in D2 between shots.

Run begins at 11:00 (note the delayed start) and ends at 17:00.

Power systems the same as for shot 1020702024.

Note: We'll have to start with an OH test to check out the data acquisition
system, as well as hardware changes made to the magnetics.

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:
DNB, ECE
Jul 11 2002 09:14:53:370AMRobert GranetzRun Plan:

Note the delayed starting time for the run. The RF will be firing into vacuum
for the first few hours of the morning before the run begins. The cell will
be open until around 11:00.

First shot will be an OH test to check the data acquisition system, as well as
hardware changes made to the magnetics.

Then load shot 1020628023 (standard SNL, 0.8 MA, 5.3 T, 1.e20 m-2) and pick
up where we left off. Over the past 2 weeks of operation, we have
developed two different startup scenarios: Ian's (segment 1 of 1020702024)
and non-Ian's. I'll start with non-Ian's, confirm its reliability, and
then perhaps switch to Ian's and compare reliabilities.

RF will probably be firing J-port into plasma, in which case we may want to
do between-shot ECDC.
Jul 11 2002 10:45:10:163AMRobert Granetz Overnight ECDC in D2 was done.

Hybrid coldstart done; no errors found

Loaded PCS from shot 1020628023 for segment 1 and shot 1020702024 for
segment 2, and confirmed that density feedback is turned off, per
Jim Irby's request.
Jul 11 2002 11:46:16:493AM1020711001Robert GranetzShot 01 -- Test. OH and EF1 only, under PLC control ... to check data system
and also magnetics hardware changes.

Next shot: we need another test the check BP15_BC, which had too
low a signal level.

Between-shot ECDC is being done now.
Jul 11 2002 11:47:37:870AM1020711002Robert GranetzShot 02 -- Test. EF3 only under PLC control. This is to check the signal
on BP15_BC, which had strangely low amplitude on shot 01.

BP15_BC looks okay (by comparison to BP15_DE).

Next shot: go for plasma.
Jul 11 2002 12:08:26:293PM1020711003Robert GranetzShot 03 -- Plasma. Good shot. 0.8 MA, 5.3 T, 0.6e20 m-2, SNL. The density
feedback signal is inverted, so Jim will fix that for the next
shot. H/D=0.09.

Next shot: turn on density feedback and increase density
to 1.e20 m-2.
Jul 11 2002 12:49:51:870PM1020711004Robert GranetzShot 04 -- Plasma. Good shot. nl_04=1.0e20 m-2, as requested. H/D=
Density feedback worked well. H/D=0.08-0.10.

Next shot: raise density to nl_04=1.2e20 m-2.
Jul 11 2002 01:27:02:943PM1020711005Robert GranetzShot 05 -- Plasma. Lots of DAQ failures...no Ip signal available. Disrupted
at 1.4 s. Mag_TR16_3 didn't receive trigger. H/D didn't go
because of the missing Ip signal.

I ran a test shot after the plasma shot and TR16_3 failed to
trigger again. Steve and I went down and unplugged/plugged in
the TR16_3 trigger cable, ran a test shot, and it's now okay.

Next shot: repeat at same density to get H/D (it needs Ip)
Jul 11 2002 05:10:53:407PM1020711006Robert GranetzShot 06 -- Plasma. Disrupted at t=0.44 s. Ip was starting to turn over, so
it may have been due to too much gas.

We're going to stop here and let the RF have the time. We're 4 for 4 on
plasma startup, using the non-IHH segment 1.

End of run.

Engineering Operator Comments
ShotTimeTypeStatusComment
111:04:55:087AMTestOkoh1, oh2u-l, ef1u-l Test
211:36:15:930AMTestOkef3 only
311:53:03:707AMPlasmaOk
412:20:15:857PMPlasmaOk
512:54:09:363PMPlasmaOk
601:28:16:103PMPlasmaBadOH1 self powered crkt fired
703:02:23:863PMTestOkCycle Test for magnetics
803:26:57:980PMTestOkCycle Test for magnetics
903:39:58:923PMTestOkcycle test
1003:52:32:253PMTestOkcycle test