Alcator C-Mod Run 1001018 Information

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Miniproposals
Miniproposal:248
Date Filed: 4/15/1999
Title:High Performance Operation
First Author:Earl Marmar
Session Leader:Earl Marmar (shots 1-22)

Operators
Session leader(s):Earl Marmar
Physics operator(s):Robert Granetz
Engineering operator(s):Bill Parkin,Bill Byford

Engineering Operator Run Comment
netz EO:Byford/Parkin

Session Leader Plans

Physics Operators Plans

Session Leader Summaries

Physics Operator Summaries
Entered: Jul 7 2004 04:37:12:300PM
Author: To Be Determined
Physics operator summary for run 1001018:

Boronization recovery and
MP 248 -- High Performance

Session leader: E. Marmar
Physics operator: R. Granetz

Summary: Shot 13 was the best (Wth=210-220 kJ), but we didn't get any trophy
shots today. Startup reliability was not very good (post-boronization
troubles?) Maximum RF power was 4.5 MW, but there were problems with
keeping all the transmitters on for the entire flattop. We did get
to vary density, triangularity, RF power, and plasma current to some
extent. There may be some kind of subtle problem with the OH2's which
cause Br to jump by 3 mT from shot-to-shot.

Scorecard: 12 plasmas
9 fizzles
0 dud
1 test
0 aborted
----------
22 total

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

Engineering setup for Wednesday, 18 October 2000:

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

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

Power system setup as on 1001013009

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-bottom as is Hybrid DISABLED

The following gate valves should be enabled, assuming no vacuum problems:
ECE, VUV, NPA (aka Beast)

DNB gate valve DISABLED.

May do ECDC in D2 between shots.

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

Run plan for Wednesday, 18 October 2000:

Boronization recovery and
MP 248 -- High Performance (Possibly also MP 282A for Dmitri)

Session leader: E. Marmar
Physics operator: R. Granetz

Goals: Go for EDA H-mode trophy shots with high RF power.

Start from shot 1001013009. Vary RF power, density, triangularity and
possibly current.

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

Overnight ECDC in D2. (Over the preceding weekend we boronized and
ECDC'd in He)

Hybrid coldstart done; no errors found

Loaded shot 1001013009, except loaded segment 1 from the most
recent shot (1001013016).

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

Shot 01 -- Test; OH's and EF1's under PLC control. All Ok.

Next shot: go for plasma.

Shot 02 -- Plasma. 1 MA, 5.4 T. Disrupted at t=1.02 s, due to an impurity
injection. No D-antenna power. Breakdown might need some tweaking,
but I'll let it settle for another shot before changing anything.
No H-modes.

Next shot: repeat with all transmitters going.

Steve Wukitch needed power room access to work on the D-transmitter.

Shot 03 -- Fizzle. Br0 was incredibly low, about -2.5 mT. Some kind of
glitch in the OH2's ? It was at -1.0 mT on the previous shot.

Next shot: increase Br0 offset by +0.5 mT

Shot 04 -- Plasma. Disrupted at t=1.12 s. Prf=2.5 MW, no D-transmitter again.
H-mode. The disruptions may be due to injections from an outer
divertor edge tile, which glows and ejects specks at the disruption.
H/D=5%.

Steve Wukitch needed power room access to work on the D-transmitter.

Next shot: ohmic only, to check on the glowing tile.

Shot 05 -- Plasma. Early VDE disruption. Not clear why. Tile did not light
up, but we didn't really get diverted.

Next shot: retry ohmic only.

Shot 06 -- Fizzle. Br0 is way negative again. OH2's don't seem to be
reproducible.

Next shot: turn the RF back on.

Shot 07 -- Fizzle. Br0 is way negative again. Almost went.

Next shot: raise Br0 by +1 mT.

Shot 08 -- Plasma. Good shot. Prf=3.2 MW, fairly constant for 0.8 s. Nice
EDA. Wth=163 kJ. H89=1.6. Divertor tile did not overheat.

Next shot: raise RF power.

Shot 09 -- Fizzle.

Next shot: change Br0 offset by -0.5 mT, and move RXU in by about
2 cm to raise the upper triangularity.

Power room access for RF testing of D into a dummy load.

Shot 10 -- Fizzle. Fields look good, fill looks good. This shot almost went.

Next shot: repeat, no changes.

Shot 11 -- Plasma. Good shot. Prf=3.6 MW. EDA H-mode. H89=2. Upper
triangularity went up to about 0.43 (it was 0.32 on the previous
plasma). H/D=7-8%.

Next shot: tailor RXU to make the upper delta more constant
throughout the RF pulse, and raise the RF power.

Shot 12 -- Plasma. Disrupted at t=1.00 s, injection. Prf=4.0 MW. Might have
been a contenda if it hadn't disrupted. The divertor tile got hot,
but we didn't see any pieces fly off.

Next shot: repeat with no changes.

Shot 13 -- Plasma. Good shot. Prf=4.4 MW. Wth=210-220 kJ. H/D=7-9%

Next shot: raise target density 10% and add a 35 volt gas puff
after t=0.9 s (turn off feedback gain on nl_04 after 0.9 s)

Shot 14 -- Fizzle.

Next shot: change IC_EF4 by -10 A

Shot 15 -- Fizzle.

Next shot: put IC_EF4 back to the value it had prior to shot 14.

Shot 16 -- Fizzle.

Next shot: add another 10 amps to IC_EF4 (to -1290 A)

Shot 17 -- Fizzle.

Next shot: reload segment 1 from shot 13.

Shot 18 -- Plasma. Good shot, but performance was not as good as in shot
13. E-port transmitter tripped out at t=1.05 s. We got the 10%
increase in target density, but no extra density during the
H-mode from the gas puff.

Next shot: decrease pre-fill pulse from 21 to 19 ms. Tweak ZCUR to
keep the plasma at -4 mm for the entire flattop.

Shot 19 -- Plasma. Good shot, but E and J tripped. H/D=7-8% ZCUR stayed
at -4 to -5 mm for the entire flattop.

Next shot: remove the gas puff during the flattop, but leave the
target density at nl_04=1.1e20 m-2.

Shot 20 -- Plasma. Good shot. Wth reached 200 kJ, but then some of the RF
faulted again.

Next shot: raise plasma current to 1.1 MA

Shot 21 -- Plasma. Disrupted at t=1.2 s. Prf=4.5 MW. Several big impurity
injections from D and J. Wth got up to 200 kJ. Performance wasn't
great.

Next shot: raise current from 1.0 to 1.2 starting at t=0.8 s.

Shot 22 -- Plasma. Disrupted at 1.02 s, shortly after getting to 1.2 MA, due
to an injection from J-antenna corner.

End of run.

Session Leader Comments
Oct 18 2000 09:51:32:187AMEarl MarmarMP248 High Performance

Boronized on Sunday and Monday; this is the first run since.

J4 has been fixed to allow for higher total power out of the transmitter
Oct 18 2000 09:52:33:653AM1001018002Earl Marmarload from 1001013009

1 MA, nl_04=1e20

plasma

ratty RF

Disrupt at 1.02 s

D-port did not fire
Oct 18 2000 10:05:13:373AM1001018003Earl Marmarfizzle
Oct 18 2000 10:43:29:390AM1001018004Earl Marmar2.4 MW ICRF; decent EDA until disruption (H89=1.5)

Disrupt at 1.13 s; divertor tile near J-port glowing after the shot
Oct 18 2000 11:36:49:123AM1001018005Earl Marmartry for an ohmic only shot

early disrupt (0.3 s)
Oct 18 2000 11:37:00:280AM1001018006Earl Marmarfizzle
Oct 18 2000 11:37:07:937AM1001018007Earl Marmarfizzle
Oct 18 2000 12:04:34:687PM1001018008Earl Marmar3 MW RF

Decent EDA; H89 ~1.6
Oct 18 2000 12:18:22:653PM1001018009Earl Marmarfizzle
Oct 18 2000 12:47:24:560PM1001018010Earl Marmarincrease upper triangularity some

fizzle
Oct 18 2000 01:13:34:967PM1001018011Earl Marmar3.5 MW RF

195 kJ stored energy

got higher upper delta

impurity injection at 1.22 s

H/D starts at .06, rises to .09
Oct 18 2000 01:41:46:360PM1001018012Earl Marmardisrupt at 1.0 s

4 Mw for ~80 ms

big ELMs on D-alpha causing RF coupling problems?
Oct 18 2000 02:01:46:403PM1001018013Earl Marmar4.5 MW

H89=2

Wtot=213 kJ

Beta_n=1.5
Oct 18 2000 02:19:10:607PM1001018014Earl Marmarraise target density by 10% to 1.1e20

keep puff on at 35 volts during H-Mode

fizzle
Oct 18 2000 02:38:02:857PM1001018015Earl Marmarfizzle
Oct 18 2000 03:23:03:983PM1001018017Earl Marmarfizzle
Oct 18 2000 03:55:00:407PM1001018018Earl Marmarplasma

3.4 MW for much of the time (E tripped at 1.05 s)
Oct 18 2000 03:55:25:827PM1001018019Earl MarmarRF touched 5 MW briefly

Many RF trips
Oct 18 2000 05:15:53:530PM1001018020Earl Marmar5 MW intermittent

Oct 18 2000 05:19:06:030PM1001018021Earl Marmar1.1 MA

4 to 4.6 MW, fairly steady

mediocre confinement in steady-state (H89 ~ 1.5)
Oct 18 2000 05:20:05:530PM1001018022Earl Marmarramp up to 1.2 MA during H-Mode

disrupt shortly after reaching full current

Physics Operator Comments
Oct 18 2000 08:22:16:953AMRobert GranetzEngineering setup for Wednesday, 18 October 2000:

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

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

Power system setup as on 1001013009

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-bottom as is Hybrid DISABLED

The following gate valves should be enabled, assuming no vacuum problems:
ECE, VUV, NPA (aka Beast)

DNB gate valve DISABLED.

May do ECDC in D2 between shots.
Oct 18 2000 08:22:35:000AMRobert GranetzRun plan for Wednesday, 18 October 2000:

Boronization recovery and
MP 248 -- High Performance (Possibly also MP 282A for Dmitri)

Session leader: E. Marmar
Physics operator: R. Granetz

Goals: Go for EDA H-mode trophy shots with high RF power.

Start from shot 1001013009. Vary RF power, density, triangularity and
possibly current.
Oct 18 2000 08:23:37:670AMRobert Granetz Overnight ECDC in D2. (Over the preceding weekend we boronized and
ECDC'd in He)

Hybrid coldstart done; no errors found

Loaded shot 1001013009, except loaded segment 1 from the most
recent shot (1001013016).
Oct 18 2000 09:09:42:670AM1001018001Robert GranetzShot 01 -- Test; OH's and EF1's under PLC control. All Ok.

Next shot: go for plasma.
Oct 18 2000 09:32:31:060AM1001018002Robert GranetzShot 02 -- Plasma. 1 MA, 5.4 T. Disrupted at t=1.02 s, due to an impurity
injection. No D-antenna power. Breakdown might need some tweaking,
but I'll let it settle for another shot before changing anything.
No H-modes.

Next shot: repeat with all transmitters going.

Steve Wukitch needed power room access to work on the D-transmitter.
Oct 18 2000 10:46:31:843AM1001018004Robert GranetzShot 04 -- Plasma. Disrupted at t=1.12 s. Prf=2.5 MW, no D-transmitter again.
H-mode. The disruptions may be due to injections from an outer
divertor edge tile, which glows and ejects specks at the disruption.
H/D=5%.

Steve Wukitch needed power room access to work on the D-transmitter.

Next shot: ohmic only, to check on the glowing tile.
Oct 18 2000 11:08:33:373AM1001018005Robert GranetzShot 05 -- Plasma. Early VDE disruption. Not clear why. Tile did not light
up, but we didn't really get diverted.

Next shot: retry ohmic only.
Oct 18 2000 11:29:22:543AM1001018006Robert GranetzShot 06 -- Fizzle. Br0 is way negative again. OH2's don't seem to be
reproducible.

Next shot: turn the RF back on.
Oct 18 2000 11:35:17:793AM1001018007Robert GranetzShot 07 -- Fizzle. Br0 is way negative again. Almost went.

Next shot: raise Br0 by +1 mT.
Oct 18 2000 12:07:51:780PM1001018008Robert GranetzShot 08 -- Plasma. Good shot. Prf=3.2 MW, fairly constant for 0.8 s. Nice
EDA. Wth=163 kJ. H89=1.6. Divertor tile did not overheat.

Next shot: raise RF power.
Oct 18 2000 12:42:28:280PM1001018009Robert GranetzShot 09 -- Fizzle.

Next shot: change Br0 offset by -0.5 mT, and move RXU in by about
2 cm to raise the upper triangularity.

Power room access for RF testing of D into a dummy load.
Oct 18 2000 12:52:41:310PM1001018010Robert GranetzShot 10 -- Fizzle. Fields look good, fill looks good. This shot almost went.

Next shot: repeat, no changes.
Oct 18 2000 01:21:45:293PM1001018011Robert GranetzShot 11 -- Plasma. Good shot. Prf=3.6 MW. EDA H-mode. H89=2. Upper
triangularity went up to about 0.43 (it was 0.32 on the previous
plasma). H/D=7-8%.

Next shot: tailor RXU to make the upper delta more constant
throughout the RF pulse, and raise the RF power.
Oct 18 2000 01:39:38:153PM1001018012Robert GranetzShot 12 -- Plasma. Disrupted at t=1.00 s, injection. Prf=4.0 MW. Might have
been a contenda if it hadn't disrupted. The divertor tile got hot,
but we didn't see any pieces fly off.

Next shot: repeat with no changes.
Oct 18 2000 02:01:38:857PM1001018013Robert GranetzShot 13 -- Plasma. Good shot. Prf=4.4 MW. Wth=210-220 kJ. H/D=7-9%

Next shot: raise target density 10% and add a 35 volt gas puff
after t=0.9 s (turn off feedback gain on nl_04 after 0.9 s)
Oct 18 2000 02:14:43:623PM1001018014Robert GranetzShot 14 -- Fizzle.

Next shot: change IC_EF4 by -10 A
Oct 18 2000 02:33:41:013PM1001018015Robert GranetzShot 15 -- Fizzle.

Next shot: put IC_EF4 back to the value it had prior to shot 14.
Oct 18 2000 02:51:59:797PM1001018016Robert GranetzShot 16 -- Fizzle.

Next shot: add another 10 amps to IC_EF4 (to -1290 A)
Oct 18 2000 03:27:22:343PM1001018018Robert GranetzShot 18 -- Plasma. Good shot, but performance was not as good as in shot
13. E-port transmitter tripped out at t=1.05 s. We got the 10%
increase in target density, but no extra density during the
H-mode from the gas puff.

Next shot: decrease pre-fill pulse from 21 to 19 ms. Tweak ZCUR to
keep the plasma at -4 mm for the entire flattop.
Oct 18 2000 03:58:00:590PM1001018019Robert GranetzShot 19 -- Plasma. Good shot, but E and J tripped. H/D=7-8% ZCUR stayed
at -4 to -5 mm for the entire flattop.

Next shot: remove the gas puff during the flattop, but leave the
target density at nl_04=1.1e20 m-2.
Oct 18 2000 04:10:27:950PM1001018020Robert GranetzShot 20 -- Plasma. Good shot. Wth reached 200 kJ, but then some of the RF
faulted again.

Next shot: raise plasma current to 1.1 MA
Oct 18 2000 04:40:42:483PM1001018021Robert GranetzShot 21 -- Plasma. Disrupted at t=1.2 s. Prf=4.5 MW. Several big impurity
injections from D and J. Wth got up to 200 kJ. Performance wasn't
great.

Next shot: raise current from 1.0 to 1.2 starting at t=0.8 s.
Oct 18 2000 05:12:17:733PM1001018022Robert GranetzShot 22 -- Plasma. Disrupted at 1.02 s, shortly after getting to 1.2 MA, due
to an injection from J-antenna corner.

End of run.

Engineering Operator Comments
ShotTimeTypeStatusComment
108:57:26:153AMTestOkOH1, OH2U, OH2L, EF1U, EF1L PLC Test
209:17:13:467AMPlasmaOk
310:02:45:140AMPlasmaOk
410:19:46:390AMPlasmaOk
510:49:55:030AMPlasmaOk
611:10:49:763AMPlasmaOk
711:29:40:623AMPlasmaOk
811:49:58:263AMPlasmaOk
912:15:26:890PMPlasmaOk
1012:44:09:577PMPlasmaOk
1112:57:18:263PMPlasmaOk
1201:21:53:390PMPlasmaOk
1301:46:57:233PMPlasmaOk
1402:08:57:013PMPlasmaOk
1502:26:34:293PMPlasmaOk
1602:46:17:890PMPlasmaOk
1702:59:29:903PMPlasmaOk
1803:12:55:247PMPlasmaOk
1903:39:02:590PMPlasmaOk
2004:02:49:590PMPlasmaOk
2104:26:25:437PMPlasmaOk
2204:50:07:513PMPlasmaOk