Alcator C-Mod Run 1000322 Information

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Miniproposals
Miniproposal:
Date Filed:
Title:
First Author:
Session Leader:Jim Irby (shots 1-9)

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

Engineering Operator Run Comment
Complete power system tests. Begin start of plasma run. Irby/Wolfe/Cochr

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Physics Operator Summaries
Entered: Jul 7 2004 04:37:10:147PM
Author: To Be Determined
Physop Summary for Wednesday, 3/22/2000

SL: Irby
PO: wolfe/granetz
EO: Cochran/Dekow

MP? : Testing and Plasma startup


Engineering setup:
-------------------
2 hours ECDC in D2 prior to the run, stopping 1 hour before run.

Begin with setup for remaining power system tests (Cochran,Dekow)
NOTE: Gas system not enabled for power tests until requested.

For plasma tests:
Power system setup as on 991103014
Fizzle detector from .08 to 1.7, short delay for TF

Gas setup - fill B-top with 6 psi of D2 Hybrid enabled
fill C-side with 30 psi of D2 Hybrid enabled
fill J-bottom with 6 psi of D2 Hybrid disabled

Run Plan:
------------------
Finish Power system tests, including commutation tests and hybrid-controlled
double swings. If j-bot valve has been connected, test it out during power
tests.

Assuming no problems, begin trying for plasma, using startup from 991103014.
We need to give Granetz time to fix the missing magnetics signals in order to
evaluate the null.

If successful in getting breakdown, evaluate cleanliness as indicated by
current evolution. We may scale back the program current from 800ka to
500 or 600kA to extend pulse length

Results:
--------
The run got off to a very late start, due primarily to computer problems
associated with the system disk getting full.

We made the most of the cell access to allow Granetz to track down the
problems observerd yesterday with several magnetics diagnostics signals going
into the new TR16 digitizer. He determined that a number of connections on the
lemo to D-connector patch panel had bad solder joints. This was repaired in
situ by the electronics shop.

The fizzle detector threshold was increased from 140mV to 190mV in order to
prevent the spurious f.d. suppression obeserved during yesterday's TF tests
(shots 23-25).

Since the power systems tests were completed yesterday, we actually planned to
start right off with plasma attempts.

Once the computer system was re-booted for the final time, we started with a
no-power (data system only) cycle. PCS was loaded from a test shot PCS_002
obtained yesterday, taken from 991103014. Some of the magnetics data failed to
store, the fizzle detector did not fire, and the hybrid m-out signals looked
like there was no feedback.

After several additional no-power tests, and standalone test shots of hybrid
and magnetics, Granetz determined that the magnetics problem was due to a
power supply being left off after the resoldering job. The hybrid test shot
produced reasonalble looking outputs, but additional full cycles behaved as if
the gains were not being switched in, and the fizzle detector still did not
go. A trip to the interface room revealed that there as an error light on the
crate controller, and the J221 had not fired. The lack of j221 gates was
consistent with both the fizzle detector lossage and the lack of gain
switching. Josh determined that the error was being caused by a process
CAMAC_CHECK on DAQA, which is used to update the web page on the camac
status. He killed this process, and the subsequent full cycle (shot
1000322004) worked for both hybrid and f.d.

Shot 5 was a full-up plasma attempt. The null looked reasonable, although Br
was ~1mT and drifting, and the EF4 currents were slightly imbalanced. We got a
flash on z-meter, CII, and h-alpha, although nothing was seen on the tv. CII
level was around .006, which is slightly high but not bad for the first
day. Irby noted a high (1.7uOhm) resistance on the oh2l coax.

The remainder of the run was spent in no-power cycles and oh / tf shots in an
effort to recover the low coax resistance we had started with. In particular,
the oh's were fired under PLC control on the reverse bridges with a normal tf
pulse to reverse the jXB forces on the coax. Following shot 9 the resistance
had reduced to 0.8uOhm. There were no further plasma attempts.

We did not test the j-bot piezo valve, mainly because we forgot it. Josh and
Ian discovered that the reason the FLUXIHH analysis job was failing was
related to the fact that the new tr16 was not set up to take the same number
of samples of magnetics data as the traq it replaced, while Ian's program
assumed that all of the magnetics signals had the same length. Granetz
modified the tree to take 12,288 samples in the tr16 to match the traq data,
solving this problem.

Josh *who was kept very busy today, also fixed a bug in the engineering power
supply control widget related to differences between IDL5.2 on the alphas and
IDL 5.0 on the Vaxen.

The main goals for this week, completion of power testing and integrated
system tests have been achieved. Production of a breakdown, albeit a fizzle,
on the first attempt at plasma is an indication that the overal system is in
good shape. The rest of the week will be devoted to preparation for plasma
runs next week, including continuing work on the DNB and RF systems.

Scorecard:
----------
Duds 0
Tests 8
Fizzles 1
Plasmas 0
======= =
shots 9

Session Leader Comments

Physics Operator Comments
Mar 22 2000 06:34:49:467AMSteve WolfeQueue manager is hung up. Tom and Josh notified by voice mail.
Try doing a coldstart anyway
It runs, all matrices respond
Mar 22 2000 10:25:55:590AMSteve WolfeAdjusted threshold on fizzle detector from .141 to .190V,
as indicated on lemo connector marked THR-> (bottom one)
(turned pot between 1/4 and 1/2 turn clockwise.)
The idea is to keep it from thinking there is current during
tf tests because of combination of offsets and tf pickup on
rogowski, as noted on shots #23-25 yesterday.

Mar 22 2000 01:26:23:390PMSteve WolfeComputers finally back up after being down all morning.
Load from shot #2 (based on 991103014)
do another coldstart
coldstart successful.
Mar 22 2000 02:18:45:640PM1000322001Steve Wolfeshot#1 - No power test; camac only.
Data looks bad. No fizzle signal.
Hybrid outputs look like pre-programmed, no feedback.

Take a hybrid test shot (004). It looks ok.
Mar 22 2000 02:41:09:950PM1000322002Steve Wolfeshot#1 - No power test; camac only.
Data looks bad. No fizzle signal.
Hybrid outputs look like pre-programmed, no feedback.

Take a hybrid test shot (004). It looks ok.
Mar 22 2000 02:43:23:500PM1000322002Steve Wolfeshot#2 - No power test; camac only.
Looks the same.

Bob left the integrator power supply off. Magnetics is screwy,
but I don''t think that accounts for the hybrid signals behavior.

Reload the pcs model, just to be sure. This doesn''t make sense!
Mar 22 2000 03:39:52:043PM1000322003Steve Wolfeshot#3- No power test; camac only.
same thing!

There is an error light on the camac.

Josh discovered that
the camac_check process was causing an error on the hybrid
crate, causing the j221 to disarm.
We watched it come in about once a minyte
Josh killed the process on daqa.

Try again.
Mar 22 2000 03:49:42:890PM1000322004Steve Wolfeshot#4- No power test; camac only.
That worked! Fd went as well.
It was the camac_check job.

Next shot: try for plasma.
Mar 22 2000 04:03:42:450PM1000322005Steve Wolfeshot#5- try for plasma.
Fizzle detector worked anyway.
Got small flash on CII, halpha
Nothing on TV.

Maybe a tiny current.
EF4 has a current imnbalance; not dead cold.
Br and Bz don''t look bad, null looks ok.
fill is at .085, a little high but it gives a flash.

Just try it again
Mar 22 2000 04:16:10:467PM1000322006Steve Wolfeshot#6- 10ka oh test only; check on oh2l coax resistance.
oh resistance is still up.

Next shot: tf + reverse bridge oh
Mar 22 2000 04:25:51:687PM1000322007Steve Wolfeshot#7- no power test
Mar 22 2000 05:04:50:827PM1000322008Steve Wolfe(Granetz taking over at Steve''s console. All of Steve''s logbook comments for
the remainder of today are actually by Granetz.)

shot#8- no-power shot cycle test
Mar 22 2000 05:12:35:187PM1000322009Steve Wolfeshot#9- OH and TF test of coax resistance.
OH1, OH2L, OH2U have negative current,
TF has positive current.

OH2''s have noticeable 60 Hz noise on them.

The OH2L coax resistance dropped back down
to 0.8 micro-ohms by the end of the pulse.

End of today''s run.

Engineering Operator Comments
ShotTimeTypeStatusComment
102:04:18:077PMTestOkNo power test only
202:25:59:810PMTestBadNo Power Test Shot
303:10:04:217PMTestOkNo Power Test only
403:40:31:420PMTestOkNo Power Test Only
503:51:08:763PMPlasmaOkFull Power System Shot
604:09:14:687PMTestOkOH Coax Test
704:22:30:327PMTestBadshot cancelled
804:40:22:170PMTestOkno power test shot only
905:04:14:043PMTestOkOH Coax Test