Alcator C-Mod Run 990716 Information

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Miniproposals
Miniproposal:214
Date Filed: 1/5/1999
Title:D and E-port RF System Commissioning
First Author:Steve Wukitch
Session Leader:Steve Wukitch (shots 1-10)

Operators
Session leader(s):Steve Wukitch
Physics operator(s):Robert Granetz
Engineering operator(s):Frank Silva

Engineering Operator Run Comment
MP 214 Granetz/Silva

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Physics Operator Summaries
Entered: Jul 7 2004 04:37:02:350PM
Author: To Be Determined
Physics operator summary for run 990716:

MP 214 -- RF conditioning

SL: Dr. Wukitch, I presume?
PO: R. Granetz

The goal for today:

Re-establish plasma operation and condition the ICRF.

Summary: After several hours of power supply work, we finally began trying for
plasmas with all supplies on shot 5. A number of tweaks to Br0, Bz0,
and pre-fill pressure finally produced a nice plasma on shot 10.
Throughout the day, we had to let the alternator spin down in order
to keep it from overheating, due to the warmth of the Charles River
cooling water. This greatly slowed down the shot rep rate. By early
afternoon, the alternator house was so warm that we had to shut down
the run early.

Scorecard: 1 plasmas
1 fizzles
6 duds (2 due to lack of one or more power supplies)
2 tests
0 aborted
----------
10 total

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

Engineering Setup for Friday, 990716:

Load from 990526005 (0.8 MA, 1.4 s long flattop, nl_04=1.0e20 m-2)

Overnight ECDC in D2 prior to run, stopping in time to begin run at 09:00

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 6 psi of H2 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:

ECE, VUV

-------------------------------------------------------------------------------
Run Plan for 990716:

MP 214 -- RF conditioning

SL: Dr. Wukitch, I presume?
PO: R. Granetz

Start by loading 990526005, an 0.8 MA, long flattop shot from the last week of
operation. Optimise vertical position for RF balance.

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

Note: overnight ECDC in D2 was done prior to this run.

Hybrid coldstart done; no errors found
($set default cmod$models:[hybrid.tcl]
$@hybinit_dispatch
$@show_bitbus_log
Use editor search to verify no occurrences of "error" nor
"not respond")
Load 990526005.

Shot 01 -- EF2L test. Still has the same problem as yesterday.

There was a delay of about 1.5 hours after shot 1 to fix EF2L

Shot 02 -- Another EF2L test, at 1.7 kA. Looks good.

Next shot: bring alternator to speed and then try for plasma.

Shot 03 -- Dud. Only EF2L was enabled. Engineering error.

Next shot: try for plasma

Shot 04 -- Dud. No EF4.

Next shot: try again

Shot 05 -- Dud. All supplies worked. Br0= -4 mT.

Next shot: increase BR_0 offset from 0.002 to 0.006 T

Shot 06 -- Dud. Null looked pretty good. Gas pressure is also normal. Don't
understand why we didn't even get a flash.

Next shot: reduce pre-fill pulse from 20 to 16 ms.

Shot 07 -- Dud.

Next shot: add 1 mT to Br offset, and increase pre-fill pulse from
16 to 24 ms.

Shot 08 -- Fizzle. Doesn't look like it hit anything.

Next shot: increase Bz a tiny amount (-1275 --> -1260 amps on EF4),
and decrease pre-fill pulse by 1 ms (to 23 ms)

Shot 09 -- Dud. Perhaps too much Bz.

Next shot: reduce Bz (-1260 amps --> -1285 amps on IC_EF4)

Shot 10 -- Plasma. Good long shot. Ip=0.8 MA, Bt=5.4 T, nl_04=1.0e20 m-2,
flattop to t=1.4 s. Ramped all the way down. Terminated at 1.84 s.
Prf=3 kW. H/D=3%. Outer gap=1.6 cm.

Run ended early due to high temperatures in the alternator house (because the
Charles River cooling water is too warm).

Session Leader Comments

Physics Operator Comments
Jul 16 1999 09:18:52:340AMRobert GranetzEngineering Setup for Friday, 990716:

Load from 990526005 (0.8 MA, 1.4 s long flattop, nl_04=1.0e20 m-2)

Overnight ECDC in D2 prior to run, stopping in time to begin run at 09:00

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 6 psi of H2 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:

ECE, VUV
Jul 16 1999 09:19:06:327AMRobert GranetzRun Plan for 990716:

MP 214 -- RF conditioning

SL: Dr. Wukitch, I presume?
PO: R. Granetz

Start by loading 990526005, an 0.8 MA, long flattop shot from the last week of
operation. Optimise vertical position for RF balance.
Jul 16 1999 09:19:44:793AMRobert Granetz Note: overnight ECDC in D2 was done prior to this run.

Hybrid coldstart done; no errors found
($set default cmod$models:[hybrid.tcl]
$@hybinit_dispatch
$@show_bitbus_log
Use editor search to verify no occurrences of "error" nor
"not respond")
Load 990526005.
Jul 16 1999 11:12:46:187AM990716001Robert GranetzShot 01 -- EF2L test. Still has the same problem as yesterday.

There was a delay of about 1.5 hours after shot 1 to fix EF2L
Jul 16 1999 11:13:01:060AM990716002Robert GranetzShot 02 -- Another EF2L test, at 1.7 kA. Looks good.

Next shot: bring alternator to speed and then try for plasma.
Jul 16 1999 11:23:02:077AM990716003Robert GranetzShot 03 -- Dud. Only EF2L was enabled. Engineering error.

Next shot: try for plasma
Jul 16 1999 11:31:09:013AM990716004Robert GranetzShot 04 -- Dud. No EF4.

Next shot: try again
Jul 16 1999 11:58:20:890AM990716005Robert GranetzShot 05 -- Dud. All supplies worked. Br0= -4 mT.

Next shot: increase BR_0 offset from 0.002 to 0.006 T
Jul 16 1999 12:22:55:920PM990716006Robert GranetzShot 06 -- Dud. Null looked pretty good. Gas pressure is also normal. Don't
understand why we didn't even get a flash.

Next shot: reduce pre-fill pulse from 20 to 16 ms.
Jul 16 1999 12:51:49:733PM990716007Robert GranetzShot 07 -- Dud.

Next shot: add 1 mT to Br offset, and increase pre-fill pulse from
16 to 24 ms.
Jul 16 1999 01:25:23:873PM990716008Robert GranetzShot 08 -- Fizzle. Doesn't look like it hit anything.

Next shot: increase Bz a tiny amount (-1275 --> -1260 amps on EF4),
and decrease pre-fill pulse by 1 ms (to 23 ms)
Jul 16 1999 01:37:06:170PM990716009Robert GranetzShot 09 -- Dud. Perhaps too much Bz.

Next shot: reduce Bz (-1260 amps --> -1285 amps on IC_EF4)
Jul 20 1999 01:18:36:840PM990716010Robert GranetzShot 10 -- Plasma. Good long shot. Ip=0.8 MA, Bt=5.4 T, nl_04=1.0e20 m-2,
flattop to t=1.4 s. Ramped all the way down. Terminated at 1.84 s.
Prf=3 kW. H/D=3%. Outer gap=1.6 cm.

Run ended early due to high temperatures in the alternator house (because the
Charles River cooling water is too warm).

Engineering Operator Comments
ShotTimeTypeStatusComment
109:32:51:340AMTestBadEF2 lower test bad. single phase
211:03:11:013AMTestOkef2 lower test improved
311:19:16:873AMTestOkef2 test, hybrid control
411:27:13:123AMTestBadno ef4
511:52:32:327AMPlasmaOkno faults, ef4 ok
612:13:26:170PMPlasmaOkno faults
712:46:11:217PMPlasmaOkno faults
801:08:17:390PMPlasmaOkno faults/fizzel
901:31:39:500PMPlasmaOkno faults
1001:52:27:343PMTestOkNo Faults/Plamsa