Alcator C-Mod Run 1030401 Information

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Miniproposals
Miniproposal:
Date Filed:
Title:
First Author:
Session Leader: Unknown (shots 2-24)

Operators
Session leader(s): Unknown
Physics operator(s):Steve Wolfe
Engineering operator(s):Bill Cochran,Gary Dekow

Engineering Operator Run Comment
Correction Coil Tests, Physop: Wolfe, Eng: Cochran/Dekow

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Physics Operator Summaries
Entered: Jul 7 2004 04:37:17:147PM
Author: To Be Determined
Physop Summary for 1030401

Power Tests of C-coils
PO: wolfe
EO: Dekow

The goals of these tests were to

1) Verify safe operation of each coil, including
a) lack of case arc'ing
b) effect of fields on pumps, solenoids, computers, etc.
c) adequate mounting of the coils to the igloo
d) adequate clamping of all cables, leads, etc.
e) adequate restraints on nearby magnetic or magnetizable objects
2) Verify/calibrate tmx operation with hybrid control
3) Evaluate field structure at the plasma for possible coil connection
configurations; compare to calculated values

*Requirements:
1) Patch panel complete and connected
2) Coil case clamps in place
3) All leads securely fastened down
4) TurboPump shields in place and secured
5) If possible, TMX current control non-linearity should be eliminated;
otherwise we will need to compensate for it in the programming.

Planned shot sequence:

0) Before energizing coils, carry out careful pre-ops inspection
A) Remove and/or secure all magnetic materials in proximity to igloo
B) Secure all cable leads to coils and patch panel
C) Check hybrid and data system operation with no-power test [1 shot]

We will need to limit in-cell activities for the duration of the power
tests. It may be advisable to use the access control system, although we will
need to cheat it in order to have in-cell observers.

All personnel in the cell should remove magnetizable objects (like credit
cards) from their pockets. Stray fields at ~1m from the coils will be in the
100 Gauss range.


I) For each of seven coils Btop, Dtop, Dbot, Gtop, Gbot, Jtop, Jbot
Pulse coil at low (1kA) and high (3kA) current [14 shots]
For each shot:
A) Visually monitor coil and nearby systems (people watching in cell)
B) Monitor fields with gaussmeters
C) Verify proper operation of all PLC/Paragon systems in the control
room
D) Observe signals on magnetics diagnostics
E) Look for pick-up on all available diagnostic signals

II) Measure coil and magnetics response in several series configurations
A) "n=1 dipole" configurations 3kA [ 4 shots]
1) +Btop -Gtop
2) +Dtop -Jtop
3) +Dbot -Jbot
4) +Dtop +Dbot -Jtop -Jbot (4 in series may be
voltage-limited)
B) "n=1 quadrupole" configuration: [ 1 shot]
+Dtop -Dbot -Jtop +Jbot
C) Helical configurations [ 2 shots]
1) +Btop +Dbot -Gtop -Jbot
2) +Btop -Dbot -Gtop +Jbot


Total of 22 "good" shots required.

Results:
--------

All tests were completed successfully. No case arc'ing was observed. There
were no problems observed with any pumps, solenoids or gate valves, or
computers. There was a small interference with the IGP1 ion gauge from the
Jbot coil, but it did not turn it off. There were no problems with the igloo
mounting of the coils. The first 3000A test of Btop coil opened the door of
JR's rack. Some cable motion was observed with some of the coils, and will
need to be addressed by improved restraints. These are noted in the logbook
(user=dekow), and/or in the paper logs kept by the in-cell observers.

Fields at approximately 1m from the coils were monitored with a gaussmeter and
found to be roughly 100Gauss at 2900A.

All shots were run under Hybrid control, which seems to work once the offset
in the current regulator is compensated for; this seems to amount to a 700A
offset in the demand waveform. The initial power test was run with a program
of 1000A, because Bill had made a change at the tmx that was felt might remove
the offset, but this turned out not to be the case. Subsequent attempts at
1000A were programmed for 1700, and for 3000A at 3700. Joe modified the PLC
upper bound to allow this to be set to 4000 so as not to clip the 3700A hybrid
programming. Operation with two coils in series resulted in
lower current despite not having maxed out the supply voltage; this seems to
indicate that the gain in the current feedback loop is too low. With four
coils in series we were only able to get up to 2300A with the voltage clamped
at 300V; for these shots, the drawn waveform was increased from 3700 to 4000,
to make sure the demand caused full voltage, but this was probably not
necessary. Increasing the demand might have helped with two coils in series,
where the voltage was only 180V, but this was not attempted.

Magnetics signals were obtained for all configurations, and should be useable
for reconstruction of the structure, given knowledge of the coil geometry. The
magnitudes of the signals were generally consistent with expectations based on
previous calculations. Several potentially useful Bp loop signals appear to be
broken, including some that were apparently working last campaign. These
include bp16_gh and bp16_jk. It was noted that we have been using the bp16_bc
loop in the processed flux, which implies that all of the other bp16 loops
have had problems in the past; it is possible that these "broken" loops will
recover once we start running disruptions. The bp16_gh loop actually appeared
to have a signal, but it seems to have the wrong sign and magnitude. Note
that the sense of the "winding" in my routine
/home/wolfe/idl/cmod/error_fields/rui_coil is apparently opposite to the
convention used for the actual coils, i.e. that positive current should
correspond to a radially outward field. I'll need to confirm this and change
it. All of the labeling in the cell appears to be correct and consistent with
the above convention.

Problems:
---------

There was a slight delay in getting started while Josh fixed a problem with
the announce routine (Pat's voice). This turned out to be caused by a
permissions issue on the audio device, which actually was symptomatic of a
more troublesome issue which is still being addressed. Apparently, when
someone exits a session by (restarting X) it leaves a
lock file around that prevents subsequent logins, even by root, from obtaining
ownership of a lot of /dev/* devices, with bad results.

The first (no-power) shot was actually recorded as 1030325012 instead of
1030401001, due to a problem with determining current_shot('cmod'). The second
shot was set up (by Josh) to be 1030401002, to avoid additional confusion.

The magnetics integrators were turned off until shot#6, resulting in very
small and puzzling responses to the first several coil tests.

There was one cycle (shot 10) hang in INIT, apparently on an ECE action. This was
quickly cleared by Josh.

Shot #11 was supposed to be 1000A on Gtop coil, but was actually 3000A because
I loaded the shot without applying the modified waveform in the all_v
screen. That's the second time I've made that mistake in two
weeks. Fortunately, nothing broke so it just ended up saving us a shot.

On the positive side, the cycle seems to take about five to five and a half
minutes, somewhat faster than last year, although we need to see how this
changes with more scopes and more data being taken.

Scorecard:
Tests 24
Duds 0
Fizzles 0
Plasmas 0
------ --
Shots 24

Session Leader Comments

Physics Operator Comments
Apr 1 2003 07:53:53:840AMSteve WolfeGetting set up for today's C-coil tests.

The goals of the tests are :
---------------------------
1) Verify safe operation of each coil, including
a) lack of case arc'ing
b) effect of fields on pumps, solenoids, computers, etc.
c) adequate mounting of the coils to the igloo
d) adequate clamping of all cables, leads, etc.
e) adequate restraints on nearby magnetic or magnetizable objects
2) Verify/calibrate tmx operation with hybrid control
3) Evaluate field structure at the plasma for possible coil connection
configurations; compare to calculated values

Requirements:
-------------
1) Patch panel complete and connected
2) Coil case clamps in place
3) All leads securely fastened down
4) TurboPump shields in place and secured
5) If possible, TMX current control non-linearity should be eliminated;
otherwise we will need to compensate for it in the programming.


The proposed shot sequence would be
------------------------------------
0) Before energizing coils, carry out careful pre-ops inspection
A) Remove and/or secure all magnetic materials in proximity to igloo
B) Secure all cable leads to coils and patch panel
C) Check hybrid and data system operation with no-power test [1 shot]


I) For each of seven coils Btop, Dtop, Dbot, Gtop, Gbot, Jtop, Jbot
Pulse coil at low (1kA) and high (3kA) current [14 shots]
For each shot:
A) Visually monitor coil and nearby systems (people watching in cell)
B) Monitor fields with gaussmeters
C) Verify proper operation of all PLC/Paragon systems in the control
room
D) Observe signals on magnetics diagnostics
E) Look for pick-up on all available diagnostic signals

II) Measure coil and magnetics response in several series configurations
A) "n=1 dipole" configurations 3kA [ 4 shots]
1) +Btop -Gtop
2) +Dtop -Jtop
3) +Dbot -Jbot
4) +Dtop +Dbot -Jtop -Jbot (4 in series may be
voltage-limited)
B) "n=1 quadrupole" configuration: [ 1 shot]
+Dtop -Dbot -Jtop +Jbot
C) Helical configurations [ 2 shots]
1) +Btop +Dbot -Gtop -Jbot
2) +Btop -Dbot -Gtop +Jbot


Total of 22 "good" shots will be required.

Apr 1 2003 08:27:49:890AMSteve WolfeBring up PCS on cmodws12. I've got an acoil waveform programmed in seg2 from testing,
but I'm going to go back to seg1 only for today.

Just for fun, zero it in seg2
Turn off seg2
In seg1 all_v screen, program a waveform at 1800A, including 800A baseline offset
I'll start the ramp at .1sec, up at .3, flat to 1.8 , down at 2.0
Load it.

Try the coldstart from the Operations menu
Still doesn't pidk up the full hloader log, but otherwise ok. All matrices respond.
Tom's put in a line saying "Hit C when done, to end the .desktop script.

Last test, do a test shot #20
Looks ok. I'm getting 2.25V out on output 10. On shot 10324016 I got about 850A
for a drawn waveform of 2V, so this ought to be ok.
Apr 1 2003 08:32:35:403AMSteve WolfeChange title in seg 1 from Startup to C-Coil test and reload
Apr 1 2003 10:24:39:957AMSteve WolfeBill has made an adjustment on the tmx regulator, so I've
redrawn the Acoil_cur waveform to 1000A to be safe. Bill will also
set the plc limit to 1.2Ka as a limit.
Apr 1 2003 11:04:00:020AM1030401001Steve Wolfeshot#1: No power test
It seems to be doing 1030325012
Didn't update the big board.

bp17-20bc have a spike at -2 sec; all others ok.
This was also showing up last week.
Bob is going to check on the integrator board.

Apr 1 2003 11:16:52:790AM1030401002Steve Wolfe1030401 shot#2: No power test; Jas fixed something to do withe shot number.
Big board updated this time.
Magentics signals ok this time.

I'm getting a hybrid demand 1.1V on the camac (with the factor of 2).
Next shot : try for 1000A on Btop coil.


Apr 1 2003 11:30:29:830AM1030401003Steve Wolfeshot#3: Try for 1000A hybrid control Btop only. PLC limit set to 1.2kA
just under 300A on thecoil.
Hardly any visible signal on the magnetics.

next shot: raise the program by 700A, and see what we get


Apr 1 2003 11:53:11:253AM1030401004Steve Wolfeshot#4: raise the program to 1700A, and see what we get; Increase PLC to 3kA.
Got just under 1000A, as expected, but I still don't see anything on the
magnetics.

Bob sees up and down on f03 and f07, nowhere else. There may be an enhancement
of noise on the upper BP loops.

next shot: program to 3700A

Apr 1 2003 12:05:00:797PM1030401005Steve Wolfeshot#5: program to 3700A; plc limit to 4000

Opened the door on JR's rack!
Got 2870A on the coil.
Seeing increased noise and some ac rise and fall on several
de and gh coils. Also, f03 and f07 now show and on/off spike of +/- 10mWb

I suspect the magnetics is not integrating or isn't hooked up right
Apr 1 2003 12:28:30:603PM1030401006Steve Wolfeshot#6: repeat with integrators turned on!
Now we have signals, at the mT level. Also we see signal
on LM_CD and LN_KA.

The polarity seems to be correct. Note that the coil sense
in the rui_coil ruotine is backward.

Next shot: Go to Dtop only at 1kA
Apr 1 2003 12:48:22:417PM1030401007Steve Wolfeshot#7: Go to Dtop only at 1kA (program 1700)
OK, polarity changed on the de_11 as expected.
Looks fine. No motion observed.

next shot: 3000A on dtop
Apr 1 2003 12:56:23:657PM1030401008Steve Wolfeshot#8: 3000A on dtop
Looks good, bp11_de =-3.5mT, makes sense.
Saw one cable move; needs to get tied down.

next shot: move on to Dbot at 1kA

Apr 1 2003 01:10:28:697PM1030401009Steve Wolfeshot#9: move on to Dbot at 1kA
small (~imT) negative signal on bp16_de, as expected.

next shot: 3000A on Dbot

Apr 1 2003 01:19:49:430PM1030401010Steve Wolfeshot#10: 3000A on Dbot
cycle hung on an ece task; jas cleared it.
Bill reports motion of the gas manifold line.

Bp16_de=-3.5mT

Next shot: Gtop at 1000A

Apr 1 2003 01:33:12:660PM1030401011Steve Wolfeshot#11: Gtop at 1000A
It came out at 3000A? I see a 1000A waveform in pcs
But it looks like I never applied the all_v screen
Physop error, that saves us a shot.

next shot: Gbot, really at 1000A this time.



Apr 1 2003 01:44:07:470PM1030401012Steve Wolfeshot#12: Gbot at 1000A (double checked)
Signals look very small everywhere.

next shot: 3000A
Apr 1 2003 02:11:04:820PM1030401013Steve Wolfeshot#13: Gbot at 3000A
Signal is positive on bp16_gh, may have the coil in backward.
Bill says the coil is wired correctly.
bp14_gh and bp15_gh are also positive, according to earlier shots should be
opposite sign of 16

next shot: Jtop at 1000A. Sort the sign out later.
Apr 1 2003 02:13:52:097PM1030401014Steve Wolfeshot#14: Jtop at 1000A
bp11_jk -1mT, looks ok. note 12 and 13 are +

next shot: 3000A on Jtop
Apr 1 2003 02:21:29:867PM1030401015Steve Wolfeshot#15: 3000A on Jtop

Looks ok, bp11_jk=-3mT
No motion.

Next shot: JBOT at 1000A
Apr 1 2003 02:33:23:723PM1030401016Steve Wolfeshot#16: JBOT at 1000A

I'm seeing nothing on BP16_JK. I think there may be a magnetics problem.

Next shot: move on to 3000A.
Apr 1 2003 02:46:02:160PM1030401017Steve Wolfeshot#17: move on to 3000A on JBOT
Still no signal on bp16jk. Looks dead, have to get Bob to look at it after the run.
BP12, 13jk are negative. So is bp17jk
Note that we're using bp16_bc for the processed data, which implies that
the JK must have been flakey at some point in the past.

Some effect on the ion gauge IGp1.

Next shot: Btop(+) and Gtop(-) in series at 3000A
Apr 1 2003 02:59:19:683PM1030401018Steve Wolfeshot#18: Btop(+) and Gtop(-) in series at 3000A
Current is lower, 2650A, V=180
Signals look reasonable.

Next shot: +Dtop -Jtop
Apr 1 2003 03:14:54:647PM1030401019Steve Wolfeshot#19: +Dtop -Jtop; I'll leave the programming the same for the two in series
cases, but I'll probably try draing 4000 for the 4 in series to compensate for
the poor voltage regulation.

Magnetics signals seem good. 2650A, 180V.

Next shot: +Dbot -Jbot
Apr 1 2003 03:30:06:433PM1030401020Steve Wolfeshot#20: +Dbot -Jbot

Looks ok, still getting ~2650A, 180V.

Next shot: 4 in series, +Dtop+Dbot -Jtop -Jbot
Apr 1 2003 03:48:13:157PM1030401021Steve Wolfeshot#21: 4 in series, +Dtop+Dbot -Jtop -Jbot; raise program to 4000A to try
to boost the current demand a bit. This is expected to rail the supply voltage.
Looks good. Voltage is pinned at 300V and we got 2280A, so that's as good as we'll get.
Demand was indeed up, at 4.1V

Next shot: +Dtop -Dbot -Jtop +Jbot
Apr 1 2003 04:04:03:697PM1030401022Steve Wolfeshot#22: 4 in series, +Dtop -Dbot -Jtop +Jbot

Looks good. bp12de - bp12jk and the 13 coils have 10mT of difference signal (n=1 component of Bz)
BP15jk looks like it may have an amplitude problem?

Current is holding at 2300A @300V.

Next shot: +Btop +Dbot -Gtop -Jbot (one helicity or the other, need to work it out.)
Apr 1 2003 04:18:59:470PM1030401023Steve Wolfeshot#23: +Btop +Dbot -Gtop -Jbot (one helicity or the other, need to work it out.)

Looks different, but I can't tell much from the raw signals. n=1 signals are in the
5mT range, which is good.

Move on to the opposite helicity: +Btop -Dbot -Gtop +Jbot
Apr 1 2003 04:27:36:503PM1030401024Steve Wolfeshot#24: Move on to the opposite helicity: +Btop -Dbot -Gtop +Jbot

Looks good. Still getting 2300A at 300V, the right signals changed sign.
It all seems to work, except that we're missing some magnetics signals.

Engineering Operator Comments
ShotTimeTypeStatusComment
211:09:12:657AMTestOkCycle Test
311:24:32:787AMTestOkB top Correction Coil Test
411:34:32:370AMTestOkB Top Correction Coil Test
511:55:05:110AMTestOkB top Correction Coil test
612:16:05:217PMTestOkB Top Correction Coil Test
712:43:07:723PMTestOkD Top Correction Coil
812:51:07:913PMTestOkD Top Correction Coil
901:05:25:470PMTestOkD Bottom Correction Coil
1001:12:56:177PMTestOkD Bottom Correction Coil Test
1101:26:35:513PMTestOkG Top Correction Coil Test
1201:39:04:403PMTestOkG Bottom Correction Coil Test
1301:47:18:000PMTestOkG Bottom Correction Coil Test
1402:09:22:497PMTestOkJ Top Correction Coil
1502:16:46:733PMTestOkJ Top Correction Coil Test
1602:27:47:623PMTestOkJ Bottom Correction Coil Test
1702:35:45:410PMTestOkJ Bottom Correction Coil Test
1802:53:56:443PMTestOk+B Top, -G Top
1903:10:22:450PMTestOk+Dtop, -Jtop Correction coil test
2003:25:59:487PMTestOk+Dbot, -Jbot correction coil test
2103:41:15:307PMTestOkCorrection Coil Test
2203:55:07:723PMTestOkCorrection Coil Test
2304:10:31:077PMTestOkCorrection Coil Test
2404:22:22:400PMTestOkCorrection Coil Test