Alcator C-Mod Run 1000531 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:Jim Irby (shots 1-23)
Session Leader:Steve Wukitch (shots 1-23)

Operators
Session leader(s):Jim Irby,Steve Wukitch
Physics operator(s):Ron Parker
Engineering operator(s):Bill Cochran,Gary Dekow

Engineering Operator Run Comment
Boronization Recovery/MP 268, ICRF Conditioning.Irby/Wukitch/Parker/Coch

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:23:977PM
Author: To Be Determined
Boronization recovery / MP 268 -- ICRF Commissioning

Session leader: J. Irby/S. Wukitch
Physics operator: R. Parker
Engineering operators: G. Dekow/B. Cochran

-------------------------------------------------------------------------------
Engineering setup for Wedensday, 1000531:

ECDC in D2 after boronization, stopping 1-2 hours prior to the run.

Run begins at 9:00 and ends at 17:00.

Power system setup as on 1000526001 (last Friday morning).

Set OH1, OH2U and OH2L fizzle delays at 300 ms.
Set TF fizzle delay at 400 ms.

Gas setup - fill B-top with 6 psi of D2 Hybrid enabled
fill B-side lower with 1 psi of Ar Hybrid DISABLED
--> **** fill B-side upper with 2 psi of Kr Hybrid DISABLED *** <-- NOTE
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:
ECE, VUV, DNB

The first two shots will be a standard OH test and a 50 kA TF test.

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

Run plan:

Start with an OH test, followed by a 50 kA TF test.

For first plasma shot, load from 1000526001 (0.8 MA, 5.4 T).

Once plasma discharges are established, load 10005160 (1 MA, 5.2 T)
to begin density scan [nl01 = 0.8,1.0,1.5,2.0]

Perform Power scan for loading studies.

Time permitting, Bt scan [4.5, 5.2, 5.8]T with all antennas.

During the day, we may try some inner-wall limited discharges, at the request
of the session leader. John Rice may also puff some krypton.

-------------------------------------------------------------------------------
Boronization was completed around 00:12 Wednesday morning
after using 144 psi of diborane for an average layer
thickness of 2106 Angstroms (about the same as 1000516).
Boronization was followed by 6:40 of ECDC in D2 at 2.e-4 Torr.
-------------------------------------------------------------------------------

001 OH test

002 plasma

003 plasma
L-mode
D: failed at step to 0.75 MW
E: ran with steps of 0.5 MW and 0.75 MW
J max faults

next shot: retune D, E, and J
remove TF waggles

faults

J3 were all DC1 arc detector
J4 were all DC0 arc detector
D were all DC0

004 plasma
L-mode
D: failed at step to 0.75 MW but improved
E: ran with steps of 0.75 MW and 0.9 MW
J max faults but ran little longer

next shot: retune D, E, and J

005 plasma
H-mode
D: improved
E: ran with steps of 0.75 MW and 1.1 MW - overloaded in H-mode
screen xbarred on fault causing the overload
J max faults but ran little longer

next shot: retune D, E, and J
square J port pulse
E-port to 1 MW with ramp to 1.4 MW
D-port ramp to 1.2 MW

006 plasma
H-mode
D: improved but max faults at high power
E: ran as programmed with one fault up to 1.4 MW
J max faults

next shot: BT-> 5.2 T and Ip-> 1.0 MA
retune D, E, and J
ramp J port pulse
E-port to 1 MW with ramp to 1.6 MW
D-port ramp to 1.4 MW

007 fizzle

008 plasma
Bt~5.2 T, Ip~1.0 MA
H-mode during D-port
E-port screen xbar fired with RF fault resulting in a screen overload (
J-port ran

next shot: repeat with retune

009 plasma
Bt~5.2 T, Ip~1.0 MA
D and E ran as programmed
J-port ran with a few faults

next shot: repeat with retune

010 plasma
Bt~5.2 T, Ip~1.0 MA
D and E ran as programmed with a few faults (~3 MW)
J-port ran with a few faults

next shot: nl01->1.2 target
begin density scan

011 fizzle

012 plasma
nl->1.2 target
D ran as programmed
E faulted thrice (FS has a hot spot and band of stuff in front)
J max faults

next shot: repeat with retunes

013 fizzle

014 computer glitch

015 plasma
runaway density
D ran
E max faults early
J ran early before faulting

next shot: retry

016 fizzle


017 plasma
J: good match early (~20 msec) then reflected jumps
D and E 3 faults each 3.1 MW net

next shot: repeat chasing High power tune for J-port
raised J-port initial power to 0.3 MW/xmtr

018 fizzle

019 dud

020 fizzle

021 plasma
D ran through
E faulted and then screen crowbar during high-power step
J3 didn't run at all, max faults
J4 ran for one 55ms period and then max faults

next shot: add 40kW front porch to J3 for tuning purposes;
change tune on J4 for the high power

022 fizzle

023 plasma, H-mode - 3.2MW from D,E
D ran through
E almost ran through, screen crowbar just after the pulse
J3 max faults, tune was awful - forw/refl = 50/50
J4 ran for 100msec

Summary:

The primary objective was to demonstrate J-port operation at target
densities higher than nl01~1.0x10^20 m^-2. We had two pulses with J4
that ran through. J3 never made it but it appeared to be tuning
related. Further investigation suggests that J3 has an error in a
calibration file that prevents accurate match calculations.

Physics Operator Summaries
Entered: Jul 7 2004 04:37:11:037PM
Author: To Be Determined
Run Plan and Engineering Setup for 1000531

Boronization Recovery/MP 268 -- ICRF Conditioning

Session Leader: J. Irby/S. Wukitch
Physics Operator: R. Parker
Engineering Operators: G. Dekow/B. Cochran

Engineering Setup:

ECDC in D2 after boronization, stopping 1-2 hours before run.

Run begins at 9:00 and ends at 17:00.

Power system setup: Same as for 1000526001

Set OH1, OH2U and OH2L fizzle delays at 300ms
Set TF fizzle delay at 400 ms


Gas setup: B-Top 6 psi D2 Hybrid Enabled
B-side lower 1 psi Argon Hybrid DISABLED
** B-side upper 2 psi Krypton Hybrid DISABLED ** NOTE!!
C-side 30 psi D2 Hybrid Enabled
J-bottom leave as is Hybrid DISABLED

The following Gate Valves should be ENABLED, assuming no vacuum problems:

ECE, VUV, DNB

The first two shots will be a standard OH test and a 50 kA TF test.

Run Plan:

Start with an OH test, followed by a 50 kA TF test

For first plasma shot, load from 1000526001 (0.8 MA, 5.4 T)

Once discharges are established, load 1000516022 (1 MA, 5.2T) to begin
density scan (n101 = 0.8, 1.0, 1.5, 2.0)

Perform power scan for loading studies

Time permitting, Bt scan (4.5, 5.2, 5.8 T)

During the day, we may try some inner-wall limited discharges, at the request
of the Session Leader. J. Rice may also puff (but not inhale) some Krypton.

Run Summary

The run began well with the 6 shots going off as programmed. This was in
spite of the fact that the cell and control room were very warm due to an
overnight failure of the chilled water system. Then with shot 7, things began
deteriorating. Shot 7 was a fizzle, and although the shot was recovered in shot
8, the magnetics began to act up, presumably because of the high temperature in
the cell. Shot 9 also ran as programmed, but no magnetics data. By shot 10, the
chilled water problem was fixed, the magnetics data reappeared and the shot
ran as programmed. The current for shot 10 was 1 MA and the field was 5.2 T. The
density was 1.0e20 before transition to H-mode. For shots 1-6, the field was
5.4 T, the current 800 kA. For the rest of the run, the startup became
unreliable. Shot 11 fizzled, shot 12 was fine. The density for shot 12, and the
rest of the run was set at 1.2e20 (before H-Mode). Then a series of problems:
shot 13 fizzled, shot 14 never ran because of a computer hangup, and shot 15
ran but the interferometer failed leading to uncontrolled density. Shot 16
fizzled, but shot 17 ran well. Shot 18 fizzled as did shot 19 (actually a dud).
The PO consulted various experts on startup but no consensus emerged on the
startup problem. The usual tweaks were applied, i.e., up and down with BR and
BZ and also pressure, but no definite correlation producing reliable startup
was found. Shot 20 fizzled, shot 21 ran, shot 22 fizzled and the last shot,
shot 23 ran. S. Wolfe noted that the base pressure was somewhat higher than
usual, between 2 and 3 e-6, so that may have contributed to the startup
problem. There was no RGA for this runday, so the composition of the base
pressure gas could not be checked.

Overall, a frustrating run with 13 shots out of 21 attempts running well and
the rest fizzles or duds. Among the 13, some were not too useful due to
diagnostic failures, although they served a useful purpose for the RF
conditioning part of the runplan. Those more experienced than the PO say that
this is not unusual for the first day after boronization. If so, this would
suggest the problem has to do more with wall conditions rather than field errors.

Session Leader Comments
May 31 2000 09:12:01:450AM1000531001Steve Wukitch001 OH test
May 31 2000 10:15:09:543AM1000531003Steve Wukitch003 plasma
L-mode
D: failed at step to 0.75 MW
E: ran with steps of 0.5 MW and 0.75 MW
J max faults

next shot: retune D, E, and J
remove TF waggles
May 31 2000 10:34:27:500AM1000531004Steve Wukitch004 plasma
L-mode
D: failed at step to 0.75 MW but improved
E: ran with steps of 0.75 MW and 0.9 MW
J max faults but ran little longer

next shot: retune D, E, and J
May 31 2000 11:04:26:937AM1000531005Steve Wukitch005 plasma
H-mode
D: improved
E: ran with steps of 0.75 MW and 1.1 MW - overloaded in H-mode - screen xbarred on fault causing the overload
J max faults but ran little longer

next shot: retune D, E, and J
square J port pulse
E-port to 1 MW with ramp to 1.4 MW
D-port ramp to 1.2 MW
May 31 2000 11:40:07:530AM1000531006Steve Wukitch006 plasma
H-mode
D: improved
E: ran as programmed with one fault up to 1.4 MW
J max faults

next shot: retune D, E, and J
ramp J port pulse
E-port to 1 MW with ramp to 1.6 MW
D-port ramp to 1.2 MW
May 31 2000 11:46:53:293AM1000531007Steve Wukitch007 fizzle
May 31 2000 12:23:43:217PM1000531008Steve Wukitch008 plasma
Bt~5.2 T, Ip~1.0 MA
H-mode during D-port
E-port screen xbar fired with RF fault resulting in a screen overload (2nd time today)
J-port ran

next shot: repeat with retune


May 31 2000 12:36:42:310PM1000531009Steve Wukitch009 plasma
Bt~5.2 T, Ip~1.0 MA
D and E ran as programmed
J-port ran with a few faults

next shot: repeat with retune


May 31 2000 01:02:00:640PM1000531010Steve Wukitch010 plasma
Bt~5.2 T, Ip~1.0 MA
D and E ran as programmed with a few faults (~3 MW)
J-port ran with a few faults

next shot: nl01->1.2 target
begin density scan


May 31 2000 01:09:52:153PM1000531011Steve Wukitch011 fizzle
May 31 2000 02:32:44:013PM1000531012Steve Wukitch012 plasma
nl->1.2 target
D ran as programmed
E faulted thrice (FS has a hot spot and band of stuff in front)
J max faults

next shot: repeat with retunes
May 31 2000 02:32:58:233PM1000531013Steve Wukitch013 fizzle
May 31 2000 02:51:45:233PM1000531015Steve Wukitch015 plasma
runaway density
D ran
E max faults early
J ran early before faulting

next shot: retry
May 31 2000 02:54:30:717PM1000531016Steve Wukitch016 fizzle
May 31 2000 03:28:54:623PM1000531017Steve Wukitch017 plasma
J: good match early (~20 msec) then reflected jumps
D and E 3 faults each 3.1 MW net

next shot: repeat chasing High power tune for J-port
raised J-port initial power to 0.3 MW/xmtr
May 31 2000 03:40:03:450PM1000531018Steve Wukitch018 fizzle
May 31 2000 03:51:37:340PM1000531019Steve Wukitch019 dud
May 31 2000 04:19:56:467PM1000531020Steve Wukitch020 fizzle
May 31 2000 04:43:45:340PM1000531021Steve Wukitch021 plasma
D ran through
E faulted and then screen crowbar during high-power step
J3 didn't run at all, max faults
J4 ran for one 55ms period and then max faults

nest shot: add 40kW front porch to J3 for tuning purposes; change tune on J4 for the high power
May 31 2000 04:47:56:140PM1000531022Steve Wukitch022 fizzle
May 31 2000 05:14:33:560PM1000531023Steve Wukitch023 plasma, H-mode - 3.2MW from D,E
D ran through
E almost ran through, screen crowbar just after the pulse
J3 max faults, tune was awful - forw/refl = 50/50
J4 ran for 100msec

Physics Operator Comments
May 31 2000 09:14:32:607AM1000531001Ron ParkerShot 1 was an OH test. Shot 2 will be a plasma shot (no TF test as had
been scheduled)
May 31 2000 09:41:35:513AM1000531002Ron Parker
Shot 2 was a plasma shot. It ran as programmed (as shot 1000526001)

Good startup.
May 31 2000 10:11:04:000AM1000531003Ron Parker
Shot 3 was a repeat of shot 2. TF still had wiggles in it. These should
be removed in next shot. Also in next shot, a small krypton pulse will
be injected at 0.4 s
May 31 2000 10:25:42:060AM1000531004Ron ParkerShot 4 ran as programmed, but TF was not flat during shot. Should be
corrected on next shot. Also, Krypton puff duration increased by 10 ms.
May 31 2000 10:52:51:750AM1000531005Ron Parker
For shot 5, no changes were made and shot continues to run as programmed.

May 31 2000 11:24:11:903AM1000531006Ron ParkerShot ran as previous shots, no changes
May 31 2000 11:49:40:530AM1000531007Ron ParkerIn this shot, the TF programming was reduced from 5.4 to 5.2 T, and the current
was increased from 0.8 to 1.0 MA. However, the shot was a fizzle.
May 31 2000 12:20:58:530PM1000531008Ron Parker
Shot 8 came back, but magnetics did not.

Problem with Camac in the cell. Temperature in the cell in the 90's.

Field was 6% lower in segment 2, i.e., after 100 ms.

Next shot will have field lowered by 6% also in segment 1.
May 31 2000 05:32:01:373PM1000531009Ron Parker
Shot ran as programmed, but problems still with magnetics.
May 31 2000 01:00:19:577PM1000531010Ron ParkerLast shot was a repeat of previous shots, no changes. Chilled water is back
in operation as are the magnetics data from camac in cell.

In the next shot, the programmed density will be set at 1.2e20.

May 31 2000 05:51:04:357PM1000531011Ron Parker
This shot was a fizzle. For nest shot lower fill back to 0.06 mT
and increase BR offset from .0003 to .0006.
May 31 2000 01:39:06:420PM1000531012Ron ParkerShot came back. Density was 1.2e20 before transition to H-Mode.
Next shot: repeat
May 31 2000 02:55:32:950PM1000531013Ron Parker
Shot fizzled
May 31 2000 02:56:22:170PM1000531014Ron Parker
Shot 14 did not run because of computer hangup
May 31 2000 02:57:14:590PM1000531015Ron ParkerDecreased EF4 Current by 20 A.
Shot ran, but interferometer failed and density was uncontolled.
May 31 2000 02:52:00:543PM1000531016Ron Parker
Shot fizzled again.
May 31 2000 03:27:09:420PM1000531017Ron Parker
For this shot, made EF4 30 A more positive.

Shot ran, breakdown a little slow. Base pressure high, but no RGA.

Next shot: Repeat. 10 ms less Krypton.
May 31 2000 03:57:09:187PM1000531018Ron Parker
This shot again fizzled. At Earl's suggestion, for next shot the fill pressure will be
lowered by ~10% and BR will be reduced by 0.5 mT.
May 31 2000 05:53:56:060PM1000531019Ron Parker
Shot 19 fizzled, possibly because base pressure was too low.
May 31 2000 05:54:28:340PM1000531020Ron Parker
For this shot, fill pressure was raised to .065 mT; also BR was
increased about .3 mT.

Shot fizzled.
May 31 2000 05:13:16:043PM1000531021Ron ParkerShot 21 finally ran after several duds, and several tweaks.
For this shot, 15 A was taken off EF4 and the fill pressure was
increased to ~0.065 mT.


May 31 2000 05:14:12:560PM1000531022Ron Parker
Shot 22 was a fizzle.
May 31 2000 05:14:52:107PM1000531023Ron Parker
Shot 23 ran as programmed.

Engineering Operator Comments
ShotTimeTypeStatusComment
109:09:56:780AMTestOkOH Coax test
209:27:39:700AMPlasmaOk
309:52:29:530AMPlasmaOk
410:15:32:983AMPlasmaOk
510:42:39:263AMPlasmaOk
611:23:02:950AMPlasmaOk
711:44:07:607AMPlasmaOk
812:02:10:310PMPlasmaOk
912:26:14:530PMPlasmaOk
1012:47:30:357PMPlasmaOk
1101:06:39:653PMPlasmaOk
1201:25:08:750PMPlasmaOk
1301:45:26:013PMPlasmaOk
1502:27:32:263PMPlasmaOk
1602:49:47:000PMPlasmaOk
1703:08:57:187PMPlasmaOk
1803:30:30:903PMPlasmaOk
1903:45:44:153PMPlasmaOk
2004:01:59:373PMPlasmaOk
2104:23:37:750PMPlasmaOk
2204:44:36:217PMPlasmaOk
2305:02:07:670PMPlasmaOk