Alcator C-Mod Run 1050316 Information

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Miniproposals
Miniproposal:326
Date Filed: 8/26/2002
Title:D, E, and J-port Antenna Evaluation and Comparison
First Author:Steve Wukitch
Session Leader:Steve Wukitch (shots 1-18)

Operators
Session leader(s):Steve Wukitch
Physics operator(s):Joseph Snipes
Engineering operator(s):Andy Pfeiffer,Bill Byford,Ed Fitzgerald

Engineering Operator Run Comment
automatically entered by signon - please replace with real comment

Session Leader Plans
Entered: Mar 16 2005 09:05:39:020AM
Author: Steve Wukitch
Plan for 16-Mar-2005
MP#326:
SL: Wukitch
PO: Snipes

Overnight ECDC in D2, bake at 60C

Power systems as on 1050315021

A-coils must be in standard lock mode suppresion configuration
+Dtop -Dbot -Jtop +Jbot

Gas setup:
-----------
fill B-Top with 6 psi D2 Hybrid Enabled (PG4)
fill B-side lower with 2 psi Ar Hybrid DISabled (PG1)
fill B-side upper with 15 psi He3 Hybrid disabled (PG2)
fill B-main (former C-side) 30 psi D2, ENabled (PG3)
fill lower capillaries (NINJA plenum) 10 psi D2

Vacuum setup:
-------------
GV1 closed, Bypass to RGA open
Pump values closed in pulse and 5 minutes after shot

Enable ECE, Z-bolo shutters (assuming no vacuum problems)

ICRF setup:
-------------
all transmitters run on at 8:30 am

---------------------------------------------------------
Plan:

We will start with vanilla discharges to compare the heating
effectiveness of the 3 antennas. We will then investigate operation
at higher neutral pressure by scanning to higher density. We will
return to more standard density and compare H-mode thresholds via
power ramps and scan current to compare impurity and density
production.
---------------------------------------------------------

Physics Operators Plans
Entered: Mar 15 2005 05:12:42:390PM
Author: Joseph Snipes
MP 326 ICRF antenna evaluation
SL: S. Wukitch
PO: J. Snipes

Overnight ECDC in D2, bake at 60C

Power systems as of 1050315023

A-coils must be in standard configuration (lock mode suppression)
+Dtop -Dbot -Jtop +Jbot (same as 1050315)

Gas setup:
___________
fill B-top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 2 psi Ar Hybrid disabled (PG1)
fill B-side upper with 15 psi He3 Hybrid enabled (PG2)
fill B-main (former C-side) with 30 psi D2, Hybrid enabled (PG3)
fill lower capillaries (NINJA plenum) with 10 psi D2

Vacuum setup:
_____________
GV1 closed, Bypass to RGA open
Pump valves closed in pulse and 5 minutes after each shot

Enable ECE, Z-bolo shutters (assuming no vacuum problems)

ICRF setup:
____________
all transmitters run on at 8:30 am

Session Leader Summaries
Entered: Mar 16 2005 05:07:52:247PM
Author: Steve Wukitch
Run Summary:

A search for an RF leakage problem and EF3 issues limited the number
of pulses today. The RF leakage problem was found to be the DC break.
We installed ~50 nF in parallel with the break after shot 5 on FMIT#4.
For shots 007-009, we ran J3 separate from J4 and except for HIREX and
neutrons (too low of power to tell). We installed a similar shield on
J3 for shot 013 and HIREX was improved but GPC2 now has pickup. We
reached 2 MW for 0.5 sec on J.

Physics Operator Summaries
Entered: Mar 16 2005 05:00:16:793PM
Author: Joseph Snipes
The run started out badly with a fault with the EF3 breaker. This turned out to be a problem with the EF3
power supply, which cost us several hours to fix. The first plasma was at 1:00 pm. The startup was not
reliable at the beginning. After a few tweaks, an extra 10 A on EF4 put things right and the plasmas had good
startups from shot 1050316009 onward. Shot 4 disrupted at 1 s perhaps due to ICRF induced impurities. Shot 9
also had an apparently LHCD induced impurity injection around 0.3 s that led to density feedback problems.
NINJA puffing of D2 after 1.5 s led to a number of MARFEs in the current decay. The active MHD antennas got
quite warm after many of these disruptions even at the 200 kA level as they glowed for up to 200 ms after many
disruptions such as shot 13. Of 18 shots, there were three test shots, 1 dud, and 14 plasmas.
Shot,Duration(s),Ipmax(MA) Shot,Duration(s),Ipmax
01 0.000 0.002 02 0.000 0.009
03 1.934 0.819 04 0.998 0.861
05 1.785 0.821 06 0.000 0.024
07 1.747 0.818 08 1.775 0.817
09 1.708 0.812 10 0.000 0.002
11 1.781 0.820 12 1.819 0.821
13 1.804 0.824 14 1.776 0.824
15 1.787 0.823 16 1.798 0.824
17 1.790 0.829 18 1.825 0.822

Finished summary for 1050316 Total of 18 shots.
18 shots. 14 plasmas. 0 fizzles. 1 duds, 3 no power tests

Session Leader Comments
Mar 16 2005 12:58:10:910PM1050316001Steve Wukitch001 EF3 test
Mar 16 2005 12:58:17:893PM1050316002Steve Wukitch002 EF3 test
Mar 16 2005 01:11:52:393PM1050316003Steve Wukitch003 5.4 T, Ip=0.8 MA, nl_04->0.8
D: 1.0 MW [1.0,1.5]sec
E: 1.0 MW [1.0,1.5]sec
J: 2.0 MW [0.6,1.5]sec modulated gate
result: plasma
D: ran 1 fault
E: ran
J: ran multiple faults
next shot: repeat until J cleans up
Mar 16 2005 01:29:47:033PM1050316004Steve Wukitch004 5.4 T, Ip=0.8 MA, nl_04->0.8
D: 1.0 MW [1.0,1.5]sec
E: 1.0 MW [1.0,1.5]sec
J: 2.0 MW [0.6,1.5]sec modulated gate
result: plasma - early disruption
D: -
E: -
J: ran multiple faults
Mar 16 2005 01:55:26:690PM1050316005Steve Wukitch005 5.4 T, Ip=0.8 MA, nl_04->0.8
D: 1.0 MW [1.0,1.5]sec
E: 1.0 MW [1.0,1.5]sec
J: 2.0 MW [0.6,1.5]sec modulated gate
result: plasma - long elmy H-mode
D: ran
E: ran
J: ran multiple faults during overlap
next shot: install extra capacitance on J4
Mar 16 2005 02:29:57:480PM1050316007Steve Wukitch007 5.4 T, Ip=0.8 MA, nl_04->0.8
D: 1.0 MW [1.0,1.5]sec
E: 1.0 MW [1.0,1.5]sec
J: 2.0 MW [0.6,1.5]sec modulated gate, 3 and 4 separated for short period
result: plasma -
D: ran
E: ran
J: ran multiple faults
RF interference on diagnostics except HIREX (neutrons may need higher power) was better with J4 than J3
Mar 16 2005 02:30:35:577PM1050316008Steve Wukitch008 5.4 T, Ip=0.8 MA, nl_04->0.8
D: 1.0 MW [1.0,1.5]sec
E: 1.0 MW [1.0,1.5]sec
J: 2.0 MW [0.6,1.5]sec modulated gate, 3 and 4 separated for short period
result: plasma -
D: ran
E: ran
J: ran multiple faults but much better than previous 4 discharges
Mar 16 2005 02:41:57:513PM1050316009Steve Wukitch009 5.4 T, Ip=0.8 MA, nl_04->0.8
D: 1.0 MW [1.0,1.5]sec
E: 1.0 MW [1.0,1.5]sec
J: 2.0 MW [0.6,1.5]sec modulated gate, 3 and 4 separated for short period
result: plasma -
D: ran
E: ran
J: ran multiple faults
next shot: return J to normal operation (overlapped)
Mar 16 2005 03:00:03:950PM1050316010Steve Wukitch010 NTP: EF3 breaker pulled before discharge
Mar 16 2005 03:18:19:153PM1050316011Steve Wukitch011 5.4 T, Ip=0.8 MA, nl_04->0.8
D: 1.0 MW [1.0,1.5]sec
E: 1.0 MW [1.0,1.5]sec
J: 2.0 MW [0.6,1.5]sec modulated gate
result: plasma
D: ran
E: ran
J: ran multiple faults (improving)
Mar 16 2005 03:29:10:403PM1050316012Steve Wukitch012 5.4 T, Ip=0.8 MA, nl_04->0.8
D: 1.0 MW [1.0,1.5]sec
E: 1.0 MW [1.0,1.5]sec
J: 2.0 MW [0.6,1.5]sec modulated gate
result: plasma
D: ran 3 faults
E: ran 2 faults
J: ran multiple faults during overlap
next shot: install extra capacitance on J3
Mar 16 2005 03:49:15:370PM1050316013Steve Wukitch013 5.4 T, Ip=0.8 MA, nl_04->0.8
D: 1.0 MW [1.0,1.5]sec
E: 1.0 MW [1.0,1.5]sec
J: 2.0 MW [0.6,1.5]sec modulated gate
result: plasma
D: ran 2 faults
E: ran
J: ran multiple faults during overlap
pickup on f-side neutral and HIREX is much improved
Mar 16 2005 04:04:08:637PM1050316014Steve Wukitch014 5.4 T, Ip=0.8 MA, nl_04->0.8
D: 1.0 MW [1.0,1.5]sec
E: 1.0 MW [1.0,1.5]sec
J: 2.0 MW [0.6,1.5]sec modulated gate
result: plasma
D: ran
E: ran
J: ran multiple faults
Mar 16 2005 04:35:22:387PM1050316015Steve Wukitch015 5.4 T, Ip=0.8 MA, nl_04->0.8
D: 1.0 MW [1.0,1.5]sec
E: 1.0 MW [1.0,1.5]sec
J: 2.0 MW [0.6,1.5]sec modulated gate
result: plasma
D: ran 1 fault
E: ran 1 fault
J: ran multiple faults
Mar 16 2005 04:35:49:230PM1050316016Steve Wukitch016 5.4 T, Ip=0.8 MA, nl_04->0.8
D: 1.0 MW [1.0,1.5]sec
E: 1.0 MW [1.0,1.5]sec
J: 2.0 MW [0.6,1.5]sec modulated gate
result: plasma - longest 4 MW shot yet
D: ran 1 fault
E: ran 1 fault
J: ran multiple faults
Mar 16 2005 04:49:02:263PM1050316017Steve Wukitch017 5.4 T, Ip=0.8 MA, nl_04->0.8
D: 1.0 MW [1.0,1.5]sec
E: 1.0 MW [1.0,1.5]sec
J: 2.0 MW [0.6,1.5]sec modulated gate
result: plasma
D: ran 1 fault
E: ran
J: ran multiple faults
Mar 16 2005 04:59:35:683PM1050316018Steve Wukitch018 5.4 T, Ip=0.8 MA, nl_04->0.8
D: 1.0 MW [1.0,1.5]sec
E: 1.0 MW [1.0,1.5]sec
J: 2.0 MW [0.6,1.5]sec modulated gate
result: plasma - best j antenna shot
D: ran 1 fault
E: ran 1 fault
J: ran multiple faults

Physics Operator Comments
Mar 16 2005 01:34:56:080PM1050316001Joseph SnipesShot 1: Copied shot 1050315023. Andy noticed that the current limits of OH2 were set to [-30,30] kA and
there was no need for that for standard operation, so they have now been changed to [-26,30] kA.
The OH1 current limits are at [-27,27] kA. He also noticed that the setup for the shots yesterday
had the wrong A-coil settings that disagreed with the actual coil setup of +Dtop -Dbot -Jtop + Jbot.
Delay due to EF3 breaker problem. EF3 test shot.
Mar 16 2005 01:08:12:830PM1050316003Joseph SnipesShot 3: Plasma attempt. Good shot with several brief H-modes.
Mar 16 2005 01:20:04:767PM1050316004Joseph SnipesShot 4: Repeat. Lots of hard x rays in the startup. Disrupted at 1 s.
Mar 16 2005 01:36:03:410PM1050316005Joseph SnipesShot 5: Enabled B-side lower (PG1) for argon puffing. Increased prepuff by 2 ms to 28 ms duration.
Good shot.
Mar 16 2005 01:56:54:440PM1050316006Joseph SnipesShot 6: Increased RCUR offset in segment 1 to 2000. Reduced prepuff by 2 ms back to 26 ms duration. Dud!
Mar 16 2005 02:09:13:357PM1050316007Joseph SnipesShot 7: Try again with RCUR offset in segment 1 back at 1500. Returned prepuff to 28 ms duration.
Good shot.
Mar 16 2005 02:23:44:857PM1050316008Joseph SnipesShot 8: Repeat. OK shot but with runaways in the startup.
Mar 16 2005 02:59:49:607PM1050316009Joseph SnipesShot 9: Increased EF4 by 10 A to -1335 A. Good startup. The plasma took a dive at 0.31 s due to problems
with the density feedback induced by an impurity injection after LHCD
at 0.25 s.
Mar 16 2005 03:00:17:590PM1050316010Joseph SnipesShot 10: No power test due to EF3 breaker pulling out in INIT.
Mar 16 2005 03:24:52:170PM1050316011Joseph SnipesShot 11: Good shot. Disruption at even 200 kA in the rampdown causes the active MHD antennas to glow after
the shot.
Mar 16 2005 03:30:27:700PM1050316012Joseph SnipesShot 12: Reduced RCUR in the rampdown to attempt to pull the plasma away from the active MHD antennas to see
if that will keep them from getting hot. Good shot. Active MHD antennas are still glowing after
the shot. Note that NINJA puffing at 1.5 s leads to an unstable MARFE
in many of these shots.
Mar 16 2005 03:49:33:090PM1050316013Joseph SnipesShot 13: RF shield put in place on J3 as well as earlier on J4 to prevent RF from radiating into the cell
and being picked up on many diagnostics. Good shot. RF pickup is no longer visible on
the ratiomatic, but is still visible on the ECE.
Mar 16 2005 04:01:23:870PM1050316014Joseph SnipesShot 14: Repeat. Good shot.
Mar 16 2005 04:14:11:827PM1050316015Joseph SnipesShot 15: Repeat. Good shot.
Mar 16 2005 04:29:22:793PM1050316016Joseph SnipesShot 16: Repeat. Good shot.
Mar 16 2005 04:42:52:247PM1050316017Joseph SnipesShot 17: Repeat. Good shot.
Mar 16 2005 04:55:38:247PM1050316018Joseph SnipesShot 18: Repeat. Good shot.

Engineering Operator Comments
ShotTimeTypeStatusComment
112:27:50:690PMTestBad
212:47:34:707PMTestOkEF3 Test OK
301:05:01:783PMPlasmaOk
401:17:25:017PMPlasmaOk
501:34:30:800PMPlasmaOk
601:55:14:330PMPlasmaOk
702:07:34:440PMPlasmaOk
802:21:11:887PMPlasmaOk
902:34:43:730PMPlasmaOk
1002:57:24:450PMPlasmaBadNo power shot because EF3 breaker opened to loss of aux power supplyux
1103:12:01:370PMPlasmaOk
1203:25:32:683PMPlasmaOk
1303:40:38:527PMPlasmaOk
1403:54:25:277PMPlasmaOk
1504:12:45:887PMPlasmaOk
1604:26:17:323PMPlasmaOk
1704:41:11:573PMPlasmaOk
1804:53:54:263PMPlasmaOk