Alcator C-Mod Run 990121 Information

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Miniproposals
Miniproposal:206
Date Filed:12/31/1998
Title:Restart Operation: January 1999
First Author:Steve Wolfe
Session Leader:Steve Wolfe (shots 1-34)

Operators
Session leader(s):Steve Wolfe
Physics operator(s):Earl Marmar
Engineering operator(s):Bill Cochran

Engineering Operator Run Comment
Resume power systems tests, then move onto mp 206 restart operation. /Wo

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:18:523PM
Author: To Be Determined
Session Leader Summary for Thurs. 990121

MP#206 Restart Operations 1999
SL wolfe
PO marmar
EO cochran

The goal for today was to finish the power tests and begin plasma
attempts. Given the lack of ECDC, the expectation was that only fizzles were
likely, at best.

These modest goals were accomplished. Power testing was completed, including
hybrid control on all supplies (except EF3), on shot 12. One flash was
obtained on shot 16. Spencer successfully opened the flappers.

The EFCL rogowski signal is still dead. Apparently it wasn't the integrator.
This signal is not essential for operation, but should be repaired ASAP.

We played with thre null and gas pre-puff, but only got the one breakdown,
which was somewhat late and had no appreciable current. The CII signal went to
.012 mW/cm2/ster, compared to typically .002 in a clean machine.

Shot 20 had an unexplained problem in that the hybrid drove OH2U to its
current rail (30kA), apparently because it thought Br was too negative. The
magnetics CAMAC failed on the same shot in a peculiar manner: trying to
restore the data indicated the crate was offline. All signals digitized at the
hybrid looked reasonable, no saturations or zeros or baseline drifts or
jumps. We scratched our heads for a long time, and took a couple of test
shots, none of which showed any problems. Then we took another full shot,
starting from the programming of 19 and making the same change as was made for
20; this shot ran successfully as far as the OH supplies were concerned
(though it was another dud).

On shot 24 the EF4 supply failed very early, at around 200A. Shot 25 was a
repeat, and EF4 didn't turn on at all. End of Run.

14 tests
10 duds (2 power supply failures)
1 fizzle
0 plasmas
--
25 shots

Physics Operator Summaries
Entered: Jul 7 2004 04:36:59:833PM
Author: To Be Determined
Physop Run Summary 990121

The goals for today were:

Test various power supplies, and the pulsed gas, then try for plasma.

The tests went well, and we attempted to get plasma on shot 13.

Played with fields and gas, and got one fizzle (shot 16).

Shot 20 had a mysterious magnetics/hybrid problem, which led to a mismatch
between OH2U and OH2L. Ran several tests, and the problem did not repeat.

23 was a dud, and 24 and 25 had problems with EF4.

See the logbook and session leader summary for details.

Session Leader Comments
Jan 21 1999 08:39:25:890AMSteve WolfeRun Plan for Thurs, 990121

MP#206 Restart Operation 1999
SL wolfe
PO marmar

Engineering setup
-----------------
Overnight ECDC in D2 (as much as possible)
Gas setup:
B-top 6psi D2 Hybrid enabled
B-side lower ** 1psi Ar NOT enabled for 1st shot
"K-side"* 30psi D2 Hybrid enabled
* Note that this valve is physically on C-side now, but the PLC screen is
not updated yet.
** If B-side lower is not ready for use, don't bother to fill the plenum

The first part of the run will be devoted to power systems testing under the
direction of the Engineering Power Systems crew (Cochran, et al.)
Specifically, we need to complete the following tests:
1) OH commutation test at 5ka, all three coils, PLC control
2) EF1 commutation test at 5ka, both coils, PLC control
3) OH double swing test under HYBRID control, all three coils
4) EF1 double swing test under HYBRID control, both coils
5) EF4 double swing test under HYBRID control
6) EFCL test to check EFCL rogowski/integrator *
7) K-side gas puff test under HYBRID control *
8) TF test under HYBRID control
* Tests 6 and 7 could be piggybacked on one or more of the other shots.

The HYBRID programming for tests 3-8 is setup on PCS shot 990120019

Once the tests are completed, we will be ready to try for a flash.

Power systems setup for plasma tests:
---------------------------------------
PF as on 980220003
TF under hybrid control, current limit set at 160kA, timing as on 980220003

PCS setup as on 990120015 for first try. Start from there and tweak up until
we get a flash or give up. If we get one, observe impurity signals, e.g. CII
signal and Z-meter to assess cleanliness. Also observe RGA after shots. If not
totally discouraged, try a limited number of shots for current rise. If it
looks dirty (as expected) resume ECDC.

Jan 21 1999 08:52:16:667AMSteve WolfeAdditions to the Power test part of the run plan:

9) EF2 and Chopper Test under hybrid control
10)Tuesday OH test (10kA no commutation, under PLC Control)


Jan 21 1999 09:09:07:330AMSteve WolfeAnother change to the Power Tests:

2) EF1 commutation test at 3ka (not 5kA)

The EF1 double swing test is also to be done at 3kA.
Jan 21 1999 09:56:54:173AM990121001Steve WolfeShot 1: OH Commutation test @5kA
K-side gas hybrid enabled

Base=1.3e-7
Very small pressure rise (onto the 6 scale only)
Ratiomatic signal on shit shooter port shows 8e-6 rise, coming up late.
Probably just needs exercising.

Commutation test looks ok.
Jan 21 1999 10:14:48:650AM990121002Steve WolfeShot 2: EF1 commutation test; turn on B-top valve as well as "K-side".
Gas to the 5 scale
Gas puffs look better.

Comm test looks ok, but EF1U seems noisy.
Jan 21 1999 10:32:15:093AM990121003Steve WolfeShot 3: HYBRID control on OH1,OH2U,OH2L; leave gas on.

All went. OH2U has a lot of noise. It's out of phase with the demand.
Oscillations are about 20msec period.
OH1 is on the current rail in the positive swing.

Retry it with lower gain on OH2U and L both.
Jan 21 1999 10:43:45:997AM990121004Steve WolfeShot 4: Reduce OH2 gains to 2 from 4.
Redraw positive swing of OH1 from 5000 to 4000A
Oscillation still there on OH2U; it looks the same.
OH1 flattops around 5000A ok this time (off the rail); there is an offset in the Hybrid bus signal

Try a PLC shot on reverse bridge, which is where the oscillation happens.
Jan 21 1999 10:54:19:587AM990121005Steve WolfeShot 5: PLC reverse bridge test at 6kA
Similar behavior on OH2U at the current limit.

Note it and move on.

GAS gets to 2e-4 on ratiomatic, still seeing a lag.
Jan 21 1999 11:02:40:607AM990121006Steve WolfeShot 6: EF1 hybrid double swing.
Looks good, but the PLC limit was set at 3000 too, so it may have been on the rail!

Do it again.
Jan 21 1999 11:09:19:290AM990121007Steve WolfeShot 7: EF1 hybrid double swing with PLC limit at 4kA

Looks good.
Jan 21 1999 11:21:23:493AM990121008Steve WolfeShot 8: EF4 double swing under hybrid control.

Only got to +1500A on reverse swing. Maybe the PLC limits got reversed.

LImits were set as if coils were in series, and they are in parallel
Need to set -4000, +8000

Jan 21 1999 11:32:11:503AM990121009Steve WolfeShot 9: re-do it with PLC limits moved.
Looks good.

Move along.
Jan 21 1999 11:45:32:147AM990121010Steve WolfeShot 10: EF2 and EFc test under hybrid control. FD back to 0.08sec

EF2 and EFC Supplies are ok, EFCL rogowski is dead.

Next, do a Tuesday test.
Jan 21 1999 12:06:44:373PM990121011Steve WolfeShot 11: Tuesday test, 10KA, no commutation, PLC control

Looks ok, maybe a little excess noise on OH2U.
Jan 21 1999 12:18:59:853PM990121012Steve WolfeShot 12: TF under hybrid control -150kA, PLC limit at 160kA.

Looks just fine.
Ready for plasma

Spencer says flap opened
Jan 21 1999 12:35:20:333PM990121013Steve WolfeShot 13: First try for plasma. Loaded from 990120015 (was 980220003)

Dud

Null looks terrible.
BR too positive. Drop offset from .005 to .0025
Increase the gas puff while we're at it.

Jan 21 1999 12:49:36:973PM990121014Steve WolfeShot 14: dud
Null looks better.

Raise the puff.

Jan 21 1999 01:03:33:837PM990121015Steve WolfeShot 15: dud
Radial field again, and Bz may be a bit positive.
Jan 21 1999 01:20:19:243PM990121016Steve WolfeShot 16: IC_EF4 from -1330 -> -1345
BR_0 from .003 -> .002

OK, we got a fizzle, <30kA

bd at 9msec, CII=.012mW/cm2/ster

I think Br is a little positive, and Bz a little negative.
Earl thinks it's a gas problem.


Jan 21 1999 01:30:47:937PM990121017Steve WolfeShot 17: Added 2msec to pg4

dud
Jan 21 1999 01:44:00:477PM990121018Steve WolfeShot 18: Add .5mT to Br

dud
Jan 21 1999 01:57:53:333PM990121019Steve WolfeShot 19: Put IC_EF4 back to -1330 from -1345
drop puff by 2msec

dud
Jan 21 1999 02:50:27:750PM990121020Steve WolfeShot 20: Br more positive by 1mT

dud

Bad Hybrid problem. It commanded very unbalanced currents in OH2's, apparently because it
thought there was a big Br error. The magnetics also failed with a crate off-line error, which
nobody can understand.

I see no bad inputs on the hybrid. It must be something subtle.

Time to test
Jan 21 1999 03:38:36:823PM990121021Steve WolfeShot 21: OH1 only PLC 10KA test (no comm.)
Can't see any magnetics problem. ??????????

Jan 21 1999 03:54:10:177PM990121022Steve WolfeShot 22: 15kA OH1 and OH2 only test (HYBRID), BR set = .0035

Seems ok. OH2U=-16200, OH2L=-14800, hybrid seems happy on both OH2U and BR_0

Try again.
Jan 21 1999 04:02:56:263PM990121023Steve WolfeShot 23: Load from 19 and change Br from .0025 to .0035 (should be just like 20?)

dud, but OH2 balance is ok. OH2U=-27600, OH2L=-26400
Too much Bz. maybe too positive on Br now too.

Whatever it did on 20 did not repeat
Jan 21 1999 04:23:17:950PM990121024Steve WolfeShot 24: Reduce IC_EF4 20A more negative.
Dud - no ef4 after -.96sec
Jan 21 1999 04:49:43:070PM990121025Steve WolfeShot 25: Try again

No EF4.

Physics Operator Comments
Jan 21 1999 10:00:29:983AM990121001Earl Marmar990121

MP 206 1999 restart

load from 990120019

OH commutation test

hybrid enable on "k-side" to test PG-3

result: got a small puff; looks like valve opened a little late
Jan 21 1999 10:13:25:800AM990121002Earl Marmarenable b-top prefill puff;

EF1 commutation test

result: got both gas puffs; still look delayed

Jan 21 1999 10:26:49:003AM990121003Earl MarmarOH double swing test under HYBRID control; all 3 coils.

more gas from "k-side"
Jan 21 1999 10:47:26:403AM990121004Earl Marmarlower prop gain on OH2-U and OH2-L from 4 to 2

lower OH1 positive swing to 4 kA from 5 kA

more gas from "k-side"
Jan 21 1999 10:55:46:873AM990121005Earl MarmarOH test under PLC control

some noise on OH2U

"k-side" about the same as on shot 4
Jan 21 1999 11:03:57:400AM990121006Earl MarmarEF1 double swing test, HYBRID control, both coils.
Jan 21 1999 11:09:18:840AM990121007Earl MarmarRetry EF1 test; raise PLC current limit
Jan 21 1999 11:20:56:273AM990121008Earl MarmarEF4 double swing test, HYBRID control
PLC limits positive swing to 1.5 kA; requested 3.0

Gas still reproducing well
Jan 21 1999 11:28:34:803AM990121009Earl MarmarRetry EF4 test, with higher PLC limits
Jan 21 1999 11:44:26:670AM990121010Earl MarmarEF2's under HYBRID control, plus EFC ("the chopper")
Jan 21 1999 12:07:12:023PM990121011Earl Marmar10 kA OH test; PLC control; no commutation ("Tuesday" test)
Jan 21 1999 12:18:42:347PM990121012Earl Marmar150 kA TF test
Jan 21 1999 12:35:12:290PM990121013Earl Marmarfirst plasma attempt of 99

load from 990120015; 800 kA fiducial, based on 980220003

dud

too much radial field
Jan 21 1999 12:51:22:167PM990121014Earl Marmarreduce BR_0 offset to 2.5 mT from 5 mT

increase prefill puff to 19 msec from 15

null looks better; dud
Jan 21 1999 01:04:41:353PM990121015Earl MarmarIncrease prepuff to 26 ms

dud; a little too much BR, Bz
Jan 21 1999 01:19:40:767PM990121016Earl MarmarBR_o offset to 2 mT
make EF4's 15 Amp more negative

fizzle

break down at 9 ms

fields don't look too bad
Jan 21 1999 01:30:06:577PM990121017Earl Marmaradd 2 msec to prepuff

now 28 msec

dud

B_R slightly negative
Jan 21 1999 01:45:01:373PM990121018Earl MarmarBR offset to 2.5 mT from 2.0 mT

dud
Jan 21 1999 01:54:47:517PM990121019Earl Marmaref4 back to -1330

decrease prepuff to 26 ms

dud

B_R about 1 mT negative
Jan 21 1999 02:42:56:760PM990121020Earl MarmarB_R offset to 3.5 mT from 2.5 mT

dud

problems with OH2 balance

looks some kind of hybrid or magnetics problem

also, no camac data from magnetics
Jan 21 1999 03:39:49:130PM990121021Earl MarmarOH only, PLC control, to test magnetics

looks ok
Jan 21 1999 03:51:48:713PM990121022Earl MarmarOH test

HyBRID control, 15 kA drawn for each coil

looks ok
Jan 21 1999 04:02:25:150PM990121023Earl MarmarReload shot 19

B_R offset to 3.5 mT from 2.5 mT

dud

too much B_Z


Jan 21 1999 04:31:49:737PM990121024Earl Marmar20 amp more negative on EF4

dud

EF4 died at -.95 seconds
Jan 21 1999 04:50:53:360PM990121025Earl Marmarretry

dud

no EF4

Engineering Operator Comments
ShotTimeTypeStatusComment
109:48:27:283AMTestOkoh1, oh2l,oh2u comm. test
210:02:51:627AMTestOkef1l,ef1u comm test
310:18:31:880AMTestOkoh1,oh2u,oh2l double swing test
410:34:22:727AMTestOkripple on oh2 reverse bridge
510:47:10:850AMTestOkoh1,oh2l,oh2u plc test
610:59:37:713AMTestOkef1u,ef1l double swing test
711:06:10:450AMTestOkef1l,ef1u double swing test
811:14:35:777AMTestOkef4 double swing test
911:23:57:483AMTestOkef4 double swing test
1011:38:29:597AMTestOkef2,efc hybrid test
1112:02:04:130PMTestOkoh coax test shot
1212:13:31:440PMTestOkTF hybrid test
1312:28:31:033PMTestOkfirst plasma attempt
1412:42:42:590PMPlasmaOkfizzle
1512:56:59:790PMPlasmaOkfizzle
1601:10:04:960PMPlasmaOkfirst plasma
1701:25:05:513PMPlasmaBadfizzle
1801:37:04:320PMPlasmaBadfizzle
1901:50:00:273PMPlasmaBadfizzle
2002:03:48:987PMPlasmaOk
2102:51:29:280PMTestOkoh1 only, 10ka, plc
2203:44:05:517PMTestOkoh1,oh2u,oh2l hybrid test
2303:57:15:853PMPlasmaOkplasma shot , no plasma
2404:11:00:650PMPlasmaBadef4 inverts early
2504:47:48:323PMPlasmaBadno ef4
2606:02:08:217PMTestOk(null)
2706:13:27:903PMTestOkNo Power EF4 Test Shot
2806:19:07:983PMTestOk(null)
2907:06:33:687PMTestOkNo Power EF4
3007:13:20:180PMTestOkNo Power EF4 Test Shot
3107:28:36:227PMTestOkNo Power EF4 Test
3207:34:13:973PMTestBadNo Power EF4 Test
3307:40:39:767PMTestOkNo Power Test EF4
3407:50:19:470PMTestOkNo Power EF4 Test