Alcator C-Mod Run 1000426 Information

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Miniproposals
Miniproposal:268
Date Filed: 4/7/2000
Title:Conditioning of D-, E-, or J-Port ICRF Antenna
First Author:Gerd Schilling
Session Leader:Gerd Schilling (shots 1-22)

Operators
Session leader(s):Gerd Schilling
Physics operator(s):Steve Wolfe
Engineering operator(s):Frank Silva,Gary Dekow

Engineering Operator Run Comment
MP#268 ICRF Conditioning/Wolfe/Silva/Dekow

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:22:837PM
Author: To Be Determined
Session Leader's Summary for Wednesday, April 26, 2000 (1000426)

SL: Schilling
PO: Wolfe
EO: Silva/Dekow

Objectives:
bring up RF in E-Port (FMIT #2) and J-Port (FMIT #3,4) antennas
continue DNB checkout
continue machine conditioning

Results:

We started putting RF power into the antennas one transmitter at a time (shots 2-5).
This brought E-Port up to 1 MW, J3 up to 0.8 MW, and J4 up to 0.7 MW. The RF pulses
were staggered through the discharge. Shot 6 disrupted relatively early at ~0.8 s, as
J3 was ramping through 0.5 MW, with some faulting going on. Shots 7 and 8 were
power tests, and plasmas with RF resumed at shot 9. Shots 9-11 had E at 1.5 MW,
J3 at 0.3 MW, and J4 at 0.4 MW, staggered. Shot 12 was a fizzle. On shot 13 we
started to overlap J3 and J4, but staggered them with respect to E; E was up to 1.3 MW,
J3 0.45 MW, and J4 0.55 MW. On shots 14-17 the power continued to slowly come up
on J3 and J4; we started to ovelap E-Port and J-Port. Power levels reached E=1 MW,
J3=0.55 MW, J4=0.65 MW, and total during the overlap =2.1 MW. For these shots
we regularly experienced disruptions, and the suspicion arose that the disruptions
were caused by RF pickup and interference in the EF4 supply. On shot 16 we delayed
E by 100 ms compared to 14 and 15 on the thought that the disruption was triggered
by total RF power, but the disruption was delayed by ~200 ms. Shot 17 was a repeat,
almost identical. Shot 18 was run with no RF, and went fine. On shot 19 we ran only E,
ramping up the power from 1-1.5 MW; no disruption. On shot 20 we put in 1.2 MW
from J3+J4 only, and it disrupted. On shot 21 we ramped E from 0.5-1.25 MW and
simultaneously added J3+J4=0.75 MW, without a disruption. Shot 22 had E with a
1-1.25 MW ramp plus J3+J4=0.9 MW, with a disruption. These last shots suggest that
a J-Port power threshold somewhat below 0.9 MW appears to interfere with EF4,
leading to a disruption. However, the time shift of E in shots 16 and 17 compared
to 14 and 15 changed the onset of the disruption, with J at ~1.2 MW. This picture is
far from clear at the moment, and we need to continue to track this mischief down.

Physics Operator Summaries
Entered: Jul 7 2004 04:37:10:410PM
Author: To Be Determined
Physop Summary for Wednesday April 26, 2000

MP#268 ICRF Commissioning
SL: Schilling
PO: wolfe
EO: Silva/Dekow

Engineering setup:
-------------------
ECDC overnight in D2, turn off 2 hours before run

Power system setup as on 1000421019
Gas setup - fill B-top with 6 psi of D2 Hybrid enabled
fill B-side lower with 1 psi of Ar Hybrid enabled
leave B-side upper as is Hybrid DISABLED
fill C-side with 30 psi of D2 Hybrid enabled
leave J-bottom as is Hybrid DISABLED

The following gate valves should be enabled, assuming no vacuum problems:
VUV and ECE

Run Plan:
---------
Begin with a standard "Tuesday" OH test.

Start plasma operations from a reload of 1000421019 (800kA, nl4=8e19, TF=5.4T)
and proceed with conditioning. The main goal of the day is to condition E-
(FMIT#2) and J-port (FMIT#3 & 4) to high power. D-port (FMIT#1) is not
expected to be available.
The DNB will attempt to open gate valves with the arc on, but no HV during
plasmas at some point during the run. This will be a minimal start on MP266.

Rice and Marmar may request permission to fire Li pellets late in some shots.
Rice will also want Argon to finish alignment/calibration of HIREX.

Results:
--------

We got off to a late start, because the new in-cell e-stop switch had been
wired incorrectly. Once this was repaired the oh test was run at ~09:30.

The first half of the run went pretty well. The second half had many
disruptions. Most of these were caused by a power systems fault which was
diagnosed as due to RF pickup, probably related to j-port antenna and/or fmit
#3 and/or 4. The immediate symptom was an IOC on EF4. We also heard a brief burst
from the power room O2 alarm, and a peak-reading rf meter registered >0.5mw/cm2
in the power room during a shot. The first occurrence of this effect was on
shot 6; shots 7 and 8 were EF4 tests, which went through fine. The next
appearance of the effect was shot #14.

Despite these problems, progress was made in conditioning both antennas,
getting up to over 2MW total power from E and J together, and about 1.3MW from
each independently.

For shot #11 and thereafter, a tf waggle up to 5.7T was inserted for the
benefit of PCI. Unfortunately, these shots more or less coincided with the
power supply problems, so there were only a few possible candidates with
e-port on at the time of the waggle.

The argon puff was increased to 75msec (shot#5-22) to increase JR's signal for
calibration. Future physops may find this level too high if they are loading
from these shots.

The dnb group ran various combinations of gate valve open, gas puff and arc
on. Having the dnb gate valve open does affect the initial pressure by about
10%, lower for gv open and no puff, 10% higher with the puff (at ~-1sec).

Earl and John exercised the LPI, getting several pellets in, when the plasma
was still around by the time they fired.

Moving the start of the outward rcur ramp earlier for shot #3 and all
subsequent shots seemed to cure the crossover vertical position thrash.

Startup was pretty reliable today. There was only one "fizzle", a 60kA lossage
following a late disruption. I played some with the gas puff and segment 1 pg3
puff, mainly to try to get rid of runaways and compensate for the dnb gas
effects. Fields looked good and were pretty stable all day.

There were numerous power room and cell accesses throughout the day. Before
one of them, one of the switches to open one of the tf breakers hung up and
started smoking. This was cleared, and worked thereafter, despite some
scorched wiring.

Scorecard:
----------

tests 3
duds 0
fizzles 1
plasmas 18
------ --
shots 22


Session Leader Comments
Apr 26 2000 09:41:55:420AM1000426001Gerd SchillingOH test
Apr 26 2000 10:24:01:873AM1000426002Gerd SchillingPlasma, RF, ramp up to ~1 MW from E-Port 1.05 - 1.5 s , ~0.4 MW from J4 0.8 - 1.05 s.
Apr 26 2000 10:34:06:373AM1000426003Gerd SchillingPlasma, RF, ~1 MW flat top from E-Port 1.05 - 1.5 s , ramp up to ~0.4 MW from J4 0.8 - 1.05 s.
Apr 26 2000 11:08:45:937AM1000426004Gerd SchillingPlasma, RF; ~1 MW flat top E-Port 1.05 - 1.5 s , ramp up to ~0.2 MW J3 0.7 - 0.8 s, ramp up to ~0.75 MW J4 0.8 - 1.05 s.
Apr 26 2000 11:25:45:077AM1000426005Gerd SchillingPlasma, RF; ~1.3 MW flat top E-Port from 1.05 - 1.5 s, ramp J3 up to ~0.7 MW from 0.6 - 0.8 s, ramp J4 up to ~0.75 MW from 0.8 - 1.05 s.
Apr 26 2000 11:44:28:030AM1000426006Gerd SchillingPlasma, RF; disrupted ~0.76 s, J3 up to ~0.5 MW.
Apr 26 2000 12:09:20:233PM1000426007Gerd SchillingPower test
Apr 26 2000 12:30:21:000PM1000426008Gerd SchillingPower test.
Apr 26 2000 12:46:38:483PM1000426009Gerd SchillingPlasma, RF; E-Port flat top at ~1.5 MW, but multiple faults and termination ~1.13 s; J3 flat top at ~0.35 MW from 0.6 - 0.9 s;
J4 flat top at ~0.45 MW from 0.75 - 1.05 s.
Apr 26 2000 12:55:51:043PM1000426010Gerd SchillingPlasma, RF; E-Port flat top at ~1.4 MW from 1.05 - 1.5 s; J3 flat top at ~0.3 MW from 0.6 - 0.9 s;
J4 flat top at ~0.4 MW from 0.75 - 1.05 s.
Apr 26 2000 01:17:21:997PM1000426011Gerd SchillingPlasma, RF; E-Port flat top at ~1.3 MW from 1.05 - 1.1 s; J3 flat top at ~0.35 MW from 0.6 - 1.05 s;
J4 flat top at ~0.4 MW from 0.6 - 1.05 s.
Apr 26 2000 02:02:56:483PM1000426013Gerd SchillingPlasma, disrupted at 1.28 s, RF; E-Port flat top at ~1.4 MW from 1.05 - 1.28 s; J3 flat top ~0.4 MW from 0.6 - 1.05 s;
J4 flat top ~0.55 MW from 0.6 - 1.05 s.
Apr 26 2000 02:14:51:030PM1000426014Gerd SchillingPlasma, disrupted at 0.9 s, RF; E-Port flat top at ~1 MW from 0.8 - 0.9 s; J3 flat top ~0.55 MW from 0.6 - 0.9 s;
J4 flat top ~0.6 MW from 0.6 - 0.9 s.
Apr 26 2000 02:35:11:217PM1000426015Gerd SchillingPlasma, disrupted at 0.92 s, RF; E-Port flat top at ~1 MW from 0.8 - 0.92 s; J3 flat top ~0.55 MW from 0.6 - 0.92 s;
J4 flat top ~0.6 MW from 0.6 - 0.92 s.
Apr 26 2000 03:14:43:123PM1000426016Gerd SchillingPlasma, disrupted at 1.12 s, RF; E-Port flat top at ~1 MW from 0.9 - 1.12 s (delayed by 0.1 s from previous shot);
J3 flat top ~0.55 MW from 0.6 - 1.12 s; J4 flat top ~0.6 MW from 0.6 - 1.12 s.
Apr 26 2000 03:29:02:700PM1000426017Gerd SchillingPlasma, disrupted at 1.1 s, RF; E-Port flat top at ~1 MW from 0.9 - 1.1 s ; J3 flat top ~0.55 MW from 0.6 - 0.95 s (fault);
J4 flat top ~0.6 MW from 0.6 - 1.1 s.
Apr 26 2000 03:55:29:293PM1000426018Gerd SchillingPlasma, RF turned off to compare with previous disrupting shots.
Apr 26 2000 04:06:45:890PM1000426019Gerd SchillingPlasma, RF; E-Port only, ramp from 1 - 1.5 MW at 0.6 - 1.3 s, faulting during last ~0.1 s.
Apr 26 2000 04:32:14:077PM1000426020Gerd SchillingPlasma, disrupted at 0.88 s, RF; J-Port only, J3 flat top at ~0.55 MW from 0.6 - 0.88 s, J4 flat top at ~0.65 MW from 0.6 - 0.88 s.
Apr 26 2000 04:51:16:170PM1000426021Gerd SchillingPlasma, RF; E-Port ramp from 0.5 - 1.25 MW from 0.6 - 1.3 s; J3 flat top at ~0.35 MW from 0.6 - 1.3 s;
J4 flat top at ~0.4 MW from 0.6 - 1.2 s (fault).
Apr 26 2000 05:18:24:983PM1000426022Gerd SchillingPlasma, disrupted at 1.12 s, RF; E-Port ramp from 1 - 1.2 MW from 0.6 - 1.12 s; J3 flat top at ~0.4 MW from 0.6 - 1.12 s;
J4 flat top at ~0.5MW from 0.6 - 1 s (faulted).

Physics Operator Comments
Apr 26 2000 07:52:34:107AMSteve Wolfeload from 1000421019 = 800ka, 8e19, 5.4T shot from Friday
coldstart at 07:45 - all matrices respond
Apr 26 2000 08:05:40:950AMSteve WolfeEngineering Setup and Run Plan for Wednesday April 26, 2000

Run to start at 9:00AM and end at 5:00PM

MP#268 ICRF Commissioning
SL: Schilling
PO: wolfe
EO: Silva/Dekow

Engineering setup:
-------------------
ECDC overnight in D2, turn off 2 hours before run

Power system setup as on 1000421019
Gas setup - fill B-top with 6 psi of D2 Hybrid enabled
fill B-side lower with 1 psi of Ar Hybrid enabled
leave B-side upper as is Hybrid DISABLED
fill C-side with 30 psi of D2 Hybrid enabled
leave J-bottom as is Hybrid DISABLED

The following gate valves should be enabled, assuming no vacuum problems:
VUV and ECE

Run Plan:
---------
Begin with a standard "Tuesday" OH test.

Start plasma operations from a reload of 1000421019 (800kA, nl4=8e19, TF=5.4T)
and proceed with conditioning. The main goal of the day is to condition E-
(FMIT#2) and J-port (FMIT#3 & 4) to high power. D-port (FMIT#1) is not
expected to be available.
The DNB will attempt to open gate valves with the arc on, but no HV) during
plasmas at some point during the run. This will be a minimal start on MP266.

Rice and Marmar may request permission to fire Li pellets late in some shots.
Rice will also want Argon to finish alignment/calibration of HIREX.

Apr 26 2000 09:45:23:780AM1000426001Steve Wolfeshot#1: Tuesday oh test
Got an up-glitch at 0.923sec on the oh2U and L currents at turn-off.
It was there last week too, just looked a little funny. It's clearly
induced by oh1 turn-off by f.d. No problem.

For shot#2: Because we had some runaways on 1000421019, some startup changes:
Increase pre-puff from 25msec to 28msec;
Start seg#1 pg3 puff at 28msec instead of 30msec.
Apr 26 2000 10:22:13:467AM1000426002Steve Wolfeshot#2: First plasma attempt
Because we had some runaways on 1000421019, some startup changes:
Increase pre-puff from 25msec to 28msec;
Start seg#1 pg3 puff at 28msec instead of 30msec.

plasma, full length. RF fired ok. Some injections, including some during rf (0.82sec(
big vertical thrash at .45sec.
RF steps up to 1MW. POssible dithers at 1.4sec
H/D below 0.1

Next shot: Move rcur shift earlier (to ~.30 sec from .4) to relieve the jump,
hopefully reduce the crossover thrash.
Apr 26 2000 10:35:53:467AM1000426003Steve Wolfeshot#3: Move rcur shift earlier (to ~.30 sec from .4) to relieve the jump,
hopefully reduce the crossover thrash.

plasma, full length, no crossover thrash, rf flat at 1MW from 1.05-1.5,
ramp to 0.5MW from 0.8-1.05
Injections at .54, 1.33 among others.

Note: Argon has been on for shots #2-3

Next shot: no pcs changes.
Apr 26 2000 11:14:55:733AM1000426004Steve Wolfeshot#4: delay Ar pulse to 0.5sec
plasma, full length, rf looks good. only one major injection, at .35sec
j-ant is giving more bolo signal than E-, although it's only 60% as high power.

next shot: increase Ar puff from 45->75msec

Apr 26 2000 11:26:37:687AM1000426005Steve Wolfeshot#5: increase Ar puff from 45->75msec
rf will try increasing e-port power, tuning j-port

plasma, injection at 1.04sec, rf 1.26MW on E, j3 also higher power, also more Prad.

next shot: No changes
Apr 26 2000 11:48:29:310AM1000426006Steve Wolfeshot#6: No changes

disrupted early .76sec, pf breaker pulled.
EF4 voltage looks bad from 0.7 sec on,
It looks like Ef1U crowbarred before the disruption.
There was also a bad injection at 0.71sec

EF4 had a spurious IOC fault; that seems to be the first problem.

Apr 26 2000 12:13:15:717PM1000426007Steve Wolfeshot#7: EF4 only test, reverse bridge
DNB will open gate valve on this test

torus gauge went to 2e-5 Torr, DNB people claim the valve didn't open.
pressure rise started at ~0.5sec is due to NINJA puff (He)
reverse bridge test is ok.

Apr 26 2000 12:25:38:700PM1000426008Steve Wolfeshot#8: EF4 only test, forward bridge
DNB will open gate valve on this test. No permissive last shot.
There was some 44 coming in before the shot. Disble VUV gate valve for #8

ef4 test ok.
dnb gas puff shows up at -1sec, rises to 3e-6 gauge (.01 mTorr abs)
Jim says less 44 increase this time.

Apr 26 2000 12:44:53:810PM1000426009Steve Wolfeshot#9: try for another plasma, DNB will open. VUV re-enabled.

plasma full length, had some runaways this time.
e-port rf faulted early.
Breakdown pressure up to .095 (dnb contribution)
had a slight hesitation in current rise.

Next shot: decrease pre-puff from 28->25msec to account for dnb puff
LPI will attempt to fire at 1.55sec
Apr 26 2000 12:59:19:513PM1000426010Steve Wolfeshot#10: decrease pre-puff from 28->25msec to account for dnb puff
LPI will attempt to fire at 1.55sec

plasma, got a pellet, nl4 up to 2e20
got about 1.5MW from E-port, up to 700kW from J
pressure=.084mTorr, still a little hesitation in current rise.

next shot: no dnb, leave pre-puff at 25msec
put in a tf wiggle for pci.
Apr 26 2000 01:24:31:890PM1000426011Steve Wolfeshot#11: no dnb, leave pre-puff at 25msec
put in a tf wiggle for pci; increase tf current limit from 160->165kA

disrupted after the pellet (1.61sec); looks like the chopper railed
small injection at 1.614 precedes the chopper thrash, and the disruption
seen on halpha, ece and bolo
Rf got 700kW out of j, and e faulted early

Next shot: increase waggle from 159 to 161kA for PCI

Apr 26 2000 01:40:29:217PM1000426012Steve Wolfeshot#12: increase waggle from 159 to 161kA for PCI

fizzle: gets to 61kA. disruption leftover? there's a big br excursion.

next shot: increase pre-puff back to 28msec
Apr 26 2000 01:53:34:187PM1000426013Steve Wolfeshot#13: increase pre-puff back to 28msec
increase waggle from 159 to 161kA for PCI

disrupts at 1.28sec, during rf,
looks like an injection at 1.20-1.22 from the antenna
some runaways at the start

Apr 26 2000 02:14:29:483PM1000426014Steve Wolfeshot#14: no changes
disrupted at .9sec, looks like another ef4 ioc fault at 0.82
rf was over 2MW (combined)
Apr 26 2000 02:34:59:733PM1000426015Steve Wolfeshot#15: start seg#1 pg3 puff at 25msec
same thing, at 0.92sec
still some runaways, not bad

Next shot: enable dnb gatevalve again
Apr 26 2000 03:09:06:360PM1000426016Steve Wolfeshot#16: enable dnb gatevalve again. they will just open, no puff, no arc
rf will delay fmit#2 by 100msec

another ef4 ioc fault, at 1.01sec. RF had some fauting, the ef4 problem is at
the max of the total rf.
There are a lot of runaways this time. bd pressure down to .073mTorr

next shot: engineers are putting ferrites on the ef4 shunt leads
dnb will puff and arc next shot.
No PCS changes.
Apr 26 2000 03:24:27:623PM1000426017Steve Wolfeshot#17: engineers are putting ferrites on the ef4 shunt leads
dnb will puff and arc next shot.
No PCS changes.

same thing. around .96sec
p(0)=.93mTorr, still getting runaways.

next shot: no rf

Apr 26 2000 03:48:20:217PM1000426018Steve Wolfeshot#18: no rf
LPI will fire at 1.0 and 1.3sec
dnb will run their arc with gv closed

disruption at 1.76sec, got one pellet at 1sec, other one didn't go?
Injections at 1.7+sec killed it off.

Next shot: e-port only, off by 1.3sec; Earl will fire at 1.3
dnb gv still closed

Apr 26 2000 04:03:29:233PM1000426019Steve Wolfeshot#19: e-port only, off by 1.3sec; Earl will fire at 1.3
dnb gv still closed

plasma full length, got a pellet

next shot: same waveform for j-port, e-port off

Apr 26 2000 04:26:03:403PM1000426020Steve Wolfeshot#20: same waveform for j-port, e-port off

and another early (.82sec) ef4 fault. prf~1.2MW
The fickle finger of fate is pointing to j-port



Apr 26 2000 04:46:12:653PM1000426021Steve Wolfeshot#21: reduce power on jport, turn eport back on.

plasma, full length with pellet. rf ramps to 2MW total.
some hards again.
there was a door ajar on EF4 cabinet until before this shot,
which may be a clue.

next shot: increase j-port power (was 800kW this time)
Apr 26 2000 05:04:47:187PM1000426022Steve Wolfeshot#22: increase j-port power (was 800kW this time);
dnb will open gv and puff, no arc

another ef4 fault, disrupts at 1.1sec; it wasn't the door.
big injection at 1.0sec, before the trip.
didn't make it to the pellet.

Engineering Operator Comments
ShotTimeTypeStatusComment
109:35:53:967AMTestOkOH1,2 10KA test OK
210:03:04:483AMPlasmaOkno faults/plasma
310:25:51:687AMPlasmaOkno faults/plasma
410:55:53:560AMPlasmaOkno faults/plasma.
511:16:18:547AMPlasmaOkno faults/plasma
611:35:15:280AMPlasmaOkEF4 problem
712:06:29:763PMPlasmaOkef4 test ok
812:18:53:763PMTestOkEF4 forward bridge test
912:29:44:810PMPlasmaOkno faults/plasma
1012:47:55:717PMPlasmaOkno faults plasma
1101:09:01:607PMPlasmaOkno faults TF at 165KA from 160KA/plasma
1201:30:49:700PMPlasmaOkno faults/dud
1301:44:22:950PMPlasmaOkno faults/disruption
1402:05:07:653PMPlasmaOkEF4 Fault
1502:28:24:687PMPlasmaOk
1602:49:28:513PMPlasmaOkEF4 Fault
1703:17:48:450PMPlasmaOkEF4 IOC fault
1803:37:43:543PMPlasmaOk
1903:57:57:060PMPlasmaOk
2004:18:01:390PMPlasmaOkEF4 IOC Fault
2104:37:55:217PMPlasmaOk
2204:56:42:903PMPlasmaOkEF4 IOC