Alcator C-Mod Run 1001208 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:Rejean Boivin (shots 1-19)
Session Leader:Steve Wukitch (shots 1-19)

Operators
Session leader(s):Rejean Boivin,Steve Wukitch
Physics operator(s):Earl Marmar
Engineering operator(s):Bill Parkin,Ed Fitzgerald

Engineering Operator Run Comment
MP #268 RF conditioning SL:Wukitch/Boivin EO:Fitzgerald/Parkin

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:26:007PM
Author: To Be Determined
Engineering setup and run plan for 1001208

MP #268 RF conditioning

Session leaders: Wukitch/Boivin
Physics operator: Marmar

-------------------------------------------------------------------------------
Engineering setup:

ECDC in D2 overnight, stopping 2 hours before the run.

Power systems as on 1001207017.

Gas setup:
fill B-top with 6 psi of D2 Hybrid enabled
fill B-side lower with 1 psi of Ar Hybrid enabled
fill B-side upper with 35 psi of D2 Hybrid DISABLED, for ECDC
fill C-side with 30 psi of D2 Hybrid enabled
leave J-bot as is Hybrid DISABLED

Enable the following gate valves: ECE, VUV, Beast, DNB

Run starts at 09:00 and ends at 17:00.

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

RF Setup:

XMTRs 3 and 4 should be made ready by 8:00 (run-on).
XMTRs 1 and 2 should be in standby mode.

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

Run Plan:

Further tests of J-port performance as a four-strap.
Re-load 1001207017, and lower nl_04. Fire J-port
into plasma. There is a plan to do a current scan.

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

001

request: reload 1001207017
BT=5.2 T, Ip=0.8 MA, nl_04~1e20 m^-2
J ramp to 1 MW [.6,1.4] sec

result: plasma
J3: 0.5 MW 3 faults
J4: 0.5 MW 3 faults
+ reflected power spikes observed on pci data (200 kHz) #3 and #4

002

request:BT=5.2 T, Ip=0.8 MA, nl_04~1e20 m^-2
J ramp to 1.5 MW [.6,1.4] sec

result: plasma, 2 elmfree H-modes
J3: 0.75 MW
J4: 0.75 MW
injections are not from J-port

003

request:BT=5.2 T, Ip=0.8 MA, nl_04~0.8e20 m^-2
J ramp to 2 MW [.6,1.4] sec

result: plasma, 2 elmfree H-modes
J3: 1.0 MW
J4: 1.0 MW max faults by 1 sec
+ neutral pressure is 0.1 mtorr

004

request:BT=5.2 T, Ip=0.8 MA, nl_04~0.8e20 m^-2
J ramp to 2.5 MW [.6,1.4] sec

result: plasma, 2 elmfree H-modes
J3: 1.3 MW
J4: 1.3 MW max faults by 1 sec
+ nasty injection from upper K-side (last front tile)

005

request:BT=5.2 T, Ip=1.0 MA, nl_04~0.8e20 m^-2
J ramp to 2.5 MW [.6,1.4] sec

result: plasma, 2 elmfree H-modes
J3: 1. MW
J4: 1.0 MW max faults by 1 sec
+ nasty injection from upper K-side (last front tile)

006

request:BT=5.2 T, Ip=1.2 MA, nl_04~0.8e20 m^-2
J ramp to 2.5 MW [.6,1.4] sec

result: plasma, 2 elmfree H-modes
J3: 1.2 MW
J4: 1.2 MW max faults by 1 sec
+ nasty injection from upper K-side (last front tile)
+ nasty spark from FS in front of strap 1

007

request:BT=5.2 T, Ip=0.8 MA, nl_04~0.8e20 m^-2
J ramp to 2.5 MW [.6,1.4] sec
phase [0,0,0,0] digital phase shifter set to 230 deg
result: plasma
J3: 0.0 MW
J4: 0.0 MW max faults early

008

request:BT=5.2 T, Ip=0.8 MA, nl_04~0.8e20 m^-2
J ramp to 2.5 MW [.6,1.4] sec
phase [0,0,0,0] digital phase shifter set to 230 deg
result: plasma - disrupted earlier (@800 kW)
J3: 0.4 MW
J4: 0.4 MW

009
fizzle

010

request:BT=5.2 T, Ip=0.8 MA, nl_04~0.8e20 m^-2
J ramp to 2.0 MW [.6,1.4] sec
phase [0,1,0,1] digital phase shifter set to 25 deg

result: plasma, EDA
J3: 1 MW
J4: 1 MW
*** no activity on the antenna

begin discharge cleaning between shots

011

request:BT=5.2 T, Ip=0.8 MA, nl_04~0.8e20 m^-2
J ramp to 2.5 MW [.6,1.4] sec
phase [0,1,0,1] digital phase shifter set to 25 deg

result: plasma, disrupted at 1.1 sec
J3: 1.25 MW
J4: 1.25 MW
antenna structure is quiet up to disruption - RF pickup in EF1 supplies?

012

request:BT=5.2 T, Ip=0.8 MA, nl_04~0.8e20 m^-2
J ramp to 2.5 MW [.6,1.4] sec
phase [0,1,0,1] digital phase shifter set to 25 deg

result: plasma - H-modes with injections
J3: 1.25 MW 4 faults
J4: 1.25 MW
nasty glow from K-side upper corner

013

request:BT=5.2 T, Ip=0.8 MA, nl_04~0.8e20 m^-2
J ramp to 2.5 MW [.6,1.4] sec
phase [0,1,0,1] digital phase shifter set to 25 deg

result: plasma - same results with more faults
J3: 1.25 MW
J4: 1.25 MW
nasty glow from K-side upper corner

014

request:BT=5.2 T, Ip=0.8 MA, nl_04~0.8e20 m^-2
J ramp to 2.5 MW [.6,1.4] sec
phase [0,1,0,1] digital phase shifter set to 0 deg

result: plasma - 1.0 sec
J3: 0.9 MW
J4: 0.9 MW
nasty glow from H-side lower corner
disrupted from 1.8 MW

015

request:BT=5.2 T, Ip=0.8 MA, nl_04~0.8e20 m^-2
J ramp to 2.5 MW [.6,1.4] sec
phase [0,1,0,1] digital phase shifter set to 0 deg

result: plasma - disrupted earlier
J3: 0.7 MW
J4: 0.7 MW
nasty glow from H-side lower corner
disrupted from 1.4 MW

016

request:BT=5.2 T, Ip=0.8 MA, nl_04~0.8e20 m^-2
D ramp to 0.75 MW
E ramp to 0.75 MW
J ramp to 2.0 MW [.6,1.4] sec
phase [0,1,0,1] digital phase shifter set to 25 deg

result: plasma - multiple H-modes
D: 0.8 before H-mode
E: 0 signal generator disconnected
J3: 0.9 MW
J4: 1 MW

need to tune all of the antennas and raise power level

017
request:BT=5.2 T, Ip=0.8 MA, nl_04~0.8e20 m^-2
D ramp to MW
E ramp to 0.75 MW
J ramp to 2.0 MW [.6,1.4] sec
phase [0,1,0,1] digital phase shifter set to 25 deg

result: plasma - multiple H-modes
D: 0.8 before H-mode
E: 0 signal generator disconnected
J3: 0.9 MW
J4: 1 MW

018

request: BT=5.2 T, Ip=0.8 MA, nl_04~0.8e20 m^-2
J squarish ramp to 1.8 MW [.6,1.4] sec
normal phase
D squarish pulse [0.6,1.5]sec 1.2 MW
E " " " 1.1 MW

result: plasma, multiple H-modes
D 1.2 MW 1 trip
E 1.1 MW 1trip
J3: 0.9 MW many trips
J4: 0.9 MW many trips


next shot
reduce J a bit in power, raise D and E.

019

request: BT=5.2 T, Ip=0.8 MA, nl_04~0.8e20 m^-2
J squarish ramp to 1.8 MW [0.6,1.5] sec
normal phase
D squarish pulse [0.6,1.5]sec 1.5 MW
E " " " 1.5 MW

result: plasma, multiple H-modes
D 1.5 MW 4 trips
E 1.5 MW 1 trip
J3: 0.9 MW 0 trip good pulse
J4: 0.9 MW 0 trip

but disrupted!

Summary:

We lowered the neutral pressure by decreasing the target density. The
visible emission over the straps appeared to decrease, but the antenna
corner light emission was still present. From spectroscopic
measurements, increased N concentrations were associated with the
corner emission. Disruptions were also correlated with excessive emission
from the antenna corner. Small changes in phase from [0,pi,0,pi]
decreased the power level from 2.5 MW at which the disruption would occur
[004,012,014] to ~1.8 MW and [0,0,0,0] phase resulted in disruptions
at 800 kW. Changing the current did not change the corner emission.
However, the corresponding hot spot location on the H-side tiles
changed consistent with the change in q (compare 006 frame 64 and 012
frame 89). This suggests there is an electric field developing on
a field line.

Physics Operator Summaries

Session Leader Comments

Physics Operator Comments
Dec 8 2000 08:43:24:093AMEarl MarmarEngineering setup and run plan for 1001208

MP #268 RF conditioning

Session leaders: Wukitch/Boivin
Physics operator: Marmar

-------------------------------------------------------------------------------
Engineering setup:

ECDC in D2 overnight, stopping 2 hours before the run.

Power systems as on 1001207017.

Gas setup:
fill B-top with 6 psi of D2 Hybrid enabled
fill B-side lower with 1 psi of Ar Hybrid enabled
fill B-side upper with 35 psi of D2 Hybrid DISABLED, for ECDC
fill C-side with 30 psi of D2 Hybrid enabled
leave J-bot as is Hybrid DISABLED

Enable the following gate valves: ECE, VUV, Beast, DNB

Run starts at 09:00 and ends at 17:00.

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

RF Setup:

XMTRs 3 and 4 should be made ready by 8:00 (run-on).
XMTRs 1 and 2 should be in standby mode.

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

Run Plan:

Further tests of J-port performance as a four-strap.
Re-load 1001207017, and lower nl_04. Fire J-port
into plasma. There is a plan to do a current scan.
Dec 8 2000 08:43:55:047AMEarl MarmarHybrid coldstart

no errors

all matrices respond
Dec 8 2000 09:07:58:903AM1001208001Earl Marmarload from 1001207017

lower zcur by 5 mm

increase rcur by 1 mm

increase prepuff by 2 msec to 20 msec (no DNB on this shot)

plasma

Dec 8 2000 09:46:38:640AM1001208001Earl MarmarAfter shot 1, alternator had a problem. There will be a delay of at least 1 hour.
Dec 8 2000 10:54:02:670AM1001208002Earl Marmarlower nl_zmeter target to 0.55 from 0.66 (attempt to reduce density by 10%)

plasma

2 h-modes
Dec 8 2000 11:34:03:123AM1001208003Earl Marmarlower nl_zmeter target to 0.4; reduce voltage preprog on PG3.

Reduce prefill puff by 1 msec

plasma


Dec 8 2000 11:34:50:000AM1001208004Earl Marmarno pcs changes

plasma
Dec 8 2000 11:56:49:107AM1001208005Earl Marmarraise Ip to 1 MA

plasma

disrupt at 1.01 s

one corner of the J antenna appears to be spewing
Dec 8 2000 12:12:35:093PM1001208006Earl Marmarraise Ip to 1.2 MA

plasma
Dec 8 2000 12:40:51:827PM1001208007Earl MarmarIp to 800 kA (load wire from shot 4)

phase scan on J-port antenna

plasma

rf tripped repeatedly

Dec 8 2000 01:03:55:747PM1001208008Earl Marmarno pcs changes

plasma

disrupt at .815 s

some RF power; nominally 0,0,0,0 phasing
Dec 8 2000 01:15:58:280PM1001208009Earl Marmarno pcs changes

dud

no EF3 --> no vertical field
Dec 8 2000 01:38:24:793PM1001208010Earl Marmarno PCS changes

plasma

solid EDA h-mode at 2 MW RF

Phase 0, pi, 0, pi
Dec 8 2000 02:04:38:263PM1001208011Earl MarmarECDC in deuterium for 5 minutes before this shot

no PCS changes

plasma

disrupt at 1.11 s

Steve Wolfe reports spurious voltage readings on EF1U just before disruption
Dec 8 2000 02:26:20:810PM1001208012Earl Marmarno pcs changes

plasma

antenna lighting up at 2.25 MW
Dec 8 2000 02:52:51:123PM1001208013Earl Marmarincrease outer gap (RCUR in by 3.5 mm)

plasma
Dec 8 2000 03:16:48:420PM1001208014Earl Marmarno pcs changes

plasma

disrupt at .997 s
Dec 8 2000 03:34:47:187PM1001208015Earl Marmarno pcs changes

plasma

disrupt at 0.916
Dec 8 2000 04:03:40:560PM1001208016Earl Marmarno PCS changes

plasma

bringing up D and E port in addition to J

Got D and J, no E on this shot
Dec 8 2000 04:21:37:687PM1001208017Earl Marmarno pcs changes

plasma

brief periods with 4 MW ICRF
Dec 8 2000 05:06:59:700PM1001208019Earl Marmarno pcs changes

plasma

disrupt at 1.18s

Engineering Operator Comments
ShotTimeTypeStatusComment
108:58:20:733AMPlasmaOk
210:42:38:420AMPlasmaOk
311:00:49:623AMPlasmaOk
411:20:50:950AMPlasmaOk
511:41:56:200AMPlasmaOk
612:03:32:717PMPlasmaOk
712:25:17:857PMPlasmaOk
812:48:49:140PMPlasmaOk
901:09:03:607PMPlasmaBadEF3 Fault, EF3 breaker opened during INIT
1001:22:23:200PMPlasmaOk
1101:47:56:107PMPlasmaOk
1202:14:46:200PMPlasmaOk
1302:38:07:467PMPlasmaOk
1403:00:55:840PMPlasmaOk
1503:25:09:280PMPlasmaBadOH1 type 1 flt, comm. failure
1603:50:04:327PMPlasmaOk
1704:14:21:030PMPlasmaOk
1804:38:40:950PMPlasmaOk
1905:03:11:607PMPlasmaOk