Alcator C-Mod Run 990806 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 1-9)

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

Engineering Operator Run Comment
MP #214 RF Conditioning/Granetz,Silva

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Physics Operator Summaries
Entered: Jul 7 2004 04:37:08:007PM
Author: To Be Determined
Physics operator summary for run 990806:

MP 214 -- RF conditioning

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

The goal for today:

Re-establish plasma operation after boronization, run some 1 MA
fiducial shots to compare to pre-boronization, and continue to
work on the ICRF.

Summary: An excellent half-day for machine operation, following last night's
boronization. Except for an initial fizzle, all shots were full
length 1 MA discharges. RF power was rather limited, and the run
ended early to allow the RF engineers access to the power room.

Jim Terry and Rob Nachtrieb were looking for differences in impurity
levels after the boronization and found surprisingly little
difference. Oxygen was eliminated, but carbon and boron remained
at essentially the same levels as yesterday.

John Goetz opened the divertor flaps on shots 7 and 8. A factor of
2 increase in Ar1+ was observed.

Scorecard: 8 plasmas
1 fizzle
0 duds (0 due to lack of one or more power supplies)
0 tests
0 aborted
----------
9 total

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

Engineering Setup for Friday, 990806:

Run will begin at 09:00.
Setup power supplies from shot 990805010 (1 MA, 5.4 T, flattop to 1.4 s)

Boronization overnight prior to run, stopping around 04:00.
Two hours of ECDC in He after boronization.

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 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 990806: MP 214 -- RF conditioning

Physics operator: R. Granetz

Re-establish yesterday's 1 MA fiducial plasmas after the overnight
boronization. Start by loading 990805010. RF may require frequent
access to the power room to debug the new power feedback control
circuit.

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

Note: The machine was boronized overnight (1900 A). This was followed
by two hours of ECDC in He prior to this run. (The machine was
last boronized on 22 April 1999.)

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 990805010 (1 MA, 5.4 T, long flattop, nl_04=1.0e20 m-2).

Shot 01 -- Fizzle. Bouncer. Null looks the same as yesterday.

Next shot: increase pre-fill pulse from 16 to 18 ms.

Shot 02 -- Plasma. Good shot. 1 MA, 5.4 T, nl=1.1e20 m-2, flattop to 1.4 s,
Ramps all the way down, terminating at t=1.86 s. Breakdown still
bounced ... just barely made it. H/D ratio = 4-5%.

Next shot: no PCS changes. Turn on RF.

Shot 03 -- Plasma. Good shot. Much better initiation (no bounce). Prf=1 MW.
H-mode from t=0.67-0.93 s. Outer gap = 7-8 mm. H/D=4-6%

Next shot: increase outer gap to 9-10 mm (reduce RCUR by 1 mm).

Shot 04 -- Plasma. Good shot. Outer gap = 10 mm. Prf=200 kW. H/D=5%.

Next shot: increase argon puff from 24 to 30 ms (at t=0.3 s)

Shot 05 -- Plasma. Good shot. Two (EDA?) H-modes. Prf=1 MW. H//D=5-7%.
H-factor is about 1.4.

Next shot: no changes.

Shot 06 -- Plasma. Good shot. Prf=0.6 MW. Dithering, but no H-modes.

Next shot: open divertor flaps at t=1.02 s.

Shot 07 -- Plasma. Good shot. Prf=0.8 MW. Dithering, and one or two short
H-modes. Flaps opened, but not obvious effects seen.

Next shot: no PCS changes. Flap at t=1.1 s.

Shot 08 -- Plasma. Good shot. Prf=0.8 MW. Dithering, and an H-mode starting
at 0.95 s. H/D=5%.

Next shot: no PCS changes. No RF (ohmic fiducial). No flappers.

Shot 09 -- Plasma. Good shot. This was a post-boronization ohmic fiducial
for Jim Terry and Rob Nachtrieb to compare to yesterday's
pre-boronization ohmic shots. Divertor flaps were not opened on
this shot.

End of run. The RF engineers want to work in the power room for the rest of
the day.

Session Leader Comments

Physics Operator Comments
Aug 5 1999 04:23:12:170PMRobert GranetzEngineering Setup for Friday, 990806:

Run will begin at 09:00.
Setup power supplies from shot 990805010 (1 MA, 5.4 T, flattop to 1.4 s)

Boronization overnight prior to run, stopping around 04:00.
Two hours of ECDC in He after boronization.

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 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
Aug 5 1999 04:23:41:437PMRobert GranetzRun Plan for 990806: MP 214 -- RF conditioning

Physics operator: R. Granetz

Re-establish yesterday's 1 MA fiducial plasmas after the overnight
boronization. Start by loading 990805010. RF may require frequent
access to the power room to debug the new power feedback control
circuit.
Aug 6 1999 08:59:33:107AMRobert Granetz Note: The machine was boronized overnight (1900 A). This was followed
by two hours of ECDC in He prior to this run. (The machine was
last boronized on 22 April 1999.)

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 990805010 (1 MA, 5.4 T, long flattop, nl_04=1.0e20 m-2).
Aug 6 1999 09:34:17:497AM990806001Robert GranetzShot 01 -- Fizzle. Bouncer. Null looks the same as yesterday.

Next shot: increase pre-fill pulse from 16 to 18 ms.
Aug 6 1999 09:41:31:920AM990806002Robert GranetzShot 02 -- Plasma. Good shot. 1 MA, 5.4 T, nl=1.1e20 m-2, flattop to 1.4 s,
Ramps all the way down, terminating at t=1.86 s. Breakdown still
bounced ... just barely made it. H/D ratio = 4-5%.

Next shot: no PCS changes. Turn on RF.
Aug 6 1999 10:03:04:293AM990806003Robert GranetzShot 03 -- Plasma. Good shot. Much better initiation (no bounce). Prf=1 MW.
H-mode from t=0.67-0.93 s. Outer gap = 7-8 mm. H/D=4-6%

Next shot: increase outer gap to 9-10 mm (reduce RCUR by 1 mm).
Aug 6 1999 10:24:09:437AM990806004Robert GranetzShot 04 -- Plasma. Good shot. Outer gap = 10 mm. Prf=200 kW. H/D=5%.

Next shot: increase argon puff from 24 to 30 ms (at t=0.3 s)
Aug 6 1999 12:07:03:700PM990806005Robert GranetzShot 05 -- Plasma. Good shot. Two (EDA?) H-modes. Prf=1 MW. H//D=5-7%.
H-factor is about 1.4.

Next shot: no changes.
Aug 6 1999 10:53:58:903AM990806006Robert GranetzShot 06 -- Plasma. Good shot. Prf=0.6 MW. Dithering, but no H-modes.

Next shot: open divertor flaps at t=1.02 s.
Aug 6 1999 11:27:42:810AM990806007Robert GranetzShot 07 -- Plasma. Good shot. Prf=0.8 MW. Dithering, and one or two short
H-modes. Flaps opened, but not obvious effects seen.

Next shot: no PCS changes. Flap at t=1.1 s.
Aug 6 1999 11:31:16:500AM990806008Robert GranetzShot 08 -- Plasma. Good shot. Prf=0.8 MW. Dithering, and an H-mode starting
at 0.95 s. H/D=5%.

Next shot: no PCS changes. No RF (ohmic fiducial). No flappers.
Aug 6 1999 12:00:51:763PM990806009Robert GranetzShot 09 -- Plasma. Good shot. This was a post-boronization ohmic fiducial
for Jim Terry and Rob Nachtrieb to compare to yesterday's
pre-boronization ohmic shots. Divertor flaps were not opened on
this shot.

End of run. The RF engineers want to work in the power room for the rest of
the day.

Engineering Operator Comments
ShotTimeTypeStatusComment
109:17:54:293AMPlasmaOkno faults
209:32:03:123AMPlasmaOkno faults
309:46:56:717AMPlasmaOkno faults
410:05:36:420AMPlasmaOk(null)
510:24:49:357AMPlasmaOkno faults
610:40:40:843AMPlasmaOkno faults
711:00:40:530AMPlasmaOkno faults
811:23:38:107AMPlasmaOkno faults
911:42:41:780AMPlasmaOkno faults