Alcator C-Mod Run 1031104 Information

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Miniproposals
Miniproposal:355
Date Filed:11/12/2003
Title:ICRF Testing & Conditioning
First Author:Steve Wukitch
Session Leader: Unknown (shots 1-34)

Operators
Session leader(s): Unknown
Physics operator(s):Steve Wolfe
Engineering operator(s):Bill Parkin,Bill Byford,Bill Cochran,Ed Fitzgerald

Engineering Operator Run Comment
PLasma Startup and Conditioning

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:34:273PM
Author: Unknown
Run summary for 1031104a
MP: #349 D-port quarter-wavelength transformers prematching performance
MP: #355 ICRF Testing and Conditioning

The primary purpose of this experiment is to demonstrate that
prematching transformers can be used to reduce the voltage in the
tuning components (phase-shifter/stub-tuner pair in the current system
and future fast-ferrite tuners). Two quarter-wavelength transformers
have been installed on the D-port transmission line network. The
system will be tested during high power operations for typical plasma
conditions. The overall performance of the antenna (power limits,
heating efficiency, impurity and density production) will be compared
with that of the unchanged E-antenna.

Summary
=======

RF conditioning continued. Plasmas are in upper-null configuration. No
H-mode has been seen even with about 5 MW RF power. J-port power is
limited by screen current in #4. Fine tuning of this transmitter is
planned.

While only a minimal reduction of the VSWR was achieved with the
quarter-wavelength transformers, their presence in the transmission
line system did not affect the power limits and the performance of the
D-antenna significantly, compared to E-antenna. The reactive loading
of the plasma, which had not been taken into account in the design of
the system, was found to result in a significant phase shift compared
to vacuum. A revised design calls for a change in the placement of the
transformers by about 7 inches.

006 Fizzle
----------------------------------------------------------------------------
007 Upper null plasma BT = 5.4 T, nl04 = 1e20 m^-2, Ip = .9 MA
D: 0.5MW MW, [0.6, 0.8] sec
E: 0.8 MW, [1.0, 1.5] sec
J: 0.75 MW x 2, [0.8, 1.5] sec
result: Plasma.
D: ran. max faults.
E: ran. 1 fault.
J: ran. ran better when E was on. >300ms

Next shot: tweak ST on D. Raise power J and E.
-----------------------------------------------------------------------------
008 Fizzle.
-----------------------------------------------------------------------------
009 Dud.
-----------------------------------------------------------------------------
010 Upper null plasma BT = 5.4 T, nl04 = 1e20 m^-2, Ip = .8 MA
D: 0.5MW MW, [0.6, 0.8] sec
E: 1.0 MW, [1.0, 1.5] sec
J: 1.0 MW x 2, [0.8, 1.5] sec
Result: Plasma.
D: ran. max faults.
E: ran. 1 fault very early.
J: ran. max faults. ~35ms continuous.
Next shot: continue to adjust d port tuning. Tweak ST J3
-----------------------------------------------------------------------------
011 Upper null plasma BT = 5.4 T, nl04 = 1e20 m^-2, Ip = .8 MA
D: 0.5MW MW, [0.6, 0.8] sec
E: 1.0 MW, [1.0, 1.5] sec
J: 1.0 MW x 2, [0.8, 1.5] sec
Result: Plasma.
D: ran. max faults.
E: ran. 1 fault very early.
J: ran. 8 faults. ~150ms continuous. better
Next shot: continue to adjust d port tuning. Tweak ST J3
-----------------------------------------------------------------------------
012 Upper null plasma BT = 5.4 T, nl04 = 1e20 m^-2, Ip = .8 MA
D: 0.5MW MW, [0.6, 0.8] sec
E: 1.0 MW, [1.0, 1.5] sec
J: 1.0 MW x 2, [0.8, 1.5] sec
Result: Plasma.
D: ran. max faults. ~30ms continuous. better
E: ran. clean.
J: ran. 3 faults. >450ms continuous. tuning good.
Next shot: Lower density to .8e20m2. Change turn-on timing of antennas.
-----------------------------------------------------------------------------
013 Upper null plasma BT = 5.4 T, nl04 = .8e20 m^-2, Ip = .8 MA
D: 0.5MW MW, [0.6, 1.2] sec
E: 1.0 MW, [0.6, 1.2] sec
J: 1.0 MW x 2, [0.8, 1.5] sec
Result: Plasma.
D: ran. 5 faults. ~200ms continuous. much better
E: ran. clean.
J: ran. clean.
Next shot: Change turn-on timing of antennas. Tweak D ST/PS. Raise D and J power.
-----------------------------------------------------------------------------
014 Fizzle
-----------------------------------------------------------------------------
015 No power cycle.
-----------------------------------------------------------------------------
015 We have two entries for shot #15
Upper null plasma BT = 5.4 T, nl04 = .8e20 m^-2, Ip = .8 MA
D: 0.6 MW [0.6, 1.5] sec
E: 1.0 MW, [0.6, 1.5] sec
J: 1.2 MW x 2, [0.8, 1.5] sec
Result: Plasma.
D: ran. 9 faults. ~250ms continuous.
E: ran. clean.
J: ran. clean. ~200ms continuous.
Next shot: Raise D power. Tweak J4 ST/PS tune.
-----------------------------------------------------------------------------
016 No target plasma
-----------------------------------------------------------------------------
017 Upper null plasma BT = 5.4 T, nl04 = .8e20 m^-2, Ip = .8 MA
D: 0.7 MW [0.6, 1.5] sec
E: 1.0 MW, [0.6, 1.5] sec
J: 1.2 MW x 2, [0.8, 1.5] sec
Result: Plasma.
D: ran. 6 faults. ~350ms continuous.
E: ran. clean.
J: ran. 8 faults. ~160ms continuous.
Next shot: Tweak J4 PS. Raise D power
-----------------------------------------------------------------------------
018 Upper null plasma BT = 5.4 T, nl04 = .8e20 m^-2, Ip = .8 MA
D: 0.8 MW [0.6, 1.5] sec
E: 1.0 MW, [0.6, 1.5] sec
J: 1.2 MW x 2, [0.8, 1.5] sec
Result: Plasma.
D: ran. 4 faults. ~450ms continuous.
E: ran. clean.
J: ran. c;eam for 180ms. Then FPA screen fault
Next shot: Raise D power.
-----------------------------------------------------------------------------
019 Upper null plasma BT = 5.4 T, nl04 = .8e20 m^-2, Ip = .8 MA
D: 0.9 MW [0.6, 1.5] sec
E: 1.0 MW, [0.6, 1.5] sec
J: 1.2 MW x 2, [0.8, 1.5] sec
Result: Plasma.
D: ran. 5 faults. ~450ms continuous.
E: ran. clean.
J: ran. c;eam for 150ms. Then FPA screen fault
Next shot: Raise D power. Lower J power.
-----------------------------------------------------------------------------
020 Upper null plasma BT = 5.4 T, nl04 = .8e20 m^-2, Ip = .8 MA
D: 1.0 MW [0.6, 1.5] sec
E: 1.0 MW, [0.6, 1.5] sec
J: 1.1 MW x 2, [0.8, 1.5] sec
Result: Plasma.
D: ran. 1 fault very early
E: ran. clean.
J: ran. 4 faults ran clean for ~400ms.
Next shot: Raise D and E power. Add a ramp J and raise power.
-----------------------------------------------------------------------------
021 Upper null plasma BT = 5.4 T, nl04 = .8e20 m^-2, Ip = .8 MA
D: 1.1 MW [0.6, 1.5] sec
E: 1.1 MW, [0.6, 1.5] sec
J: 1.2 MW x 2, [0.6, 1.5] sec
Result: Plasma.
D: ran. 9 faults. Ran clean for >500ms
E: ran. clean.
J: ran clean for ~200ms then FPA screen I fault.
Next shot: Raise D and E. Lower J.
-----------------------------------------------------------------------------
022 NTP
-----------------------------------------------------------------------------
023 Upper null plasma BT = 5.4 T, nl04 = .8e20 m^-2, Ip = .8 MA
D: 1.2 MW [0.6, 1.5] sec
E: 1.2 MW, [0.6, 1.5] sec
J: 1.1 MW x 2 [0.6, 1.5] sec
Result: Plasma.
D: ran. max faults. Ran clean for >150ms
E: ran. clean.
J: ran. max faults. Ran clean for ~200ms
Next shot: No power changes. Change start time on J back to 0.8sec.
-----------------------------------------------------------------------------
025 NTP
-----------------------------------------------------------------------------
026 NTP
-----------------------------------------------------------------------------
028 BT = 5.4 T, nl04 = .8e20 m^-2, Ip = .8 MA, SNU
D: 1.1 MW [0.6, 1.5] sec
E: 1.0 MW, [0.6, 1.5] sec
J: 1.1 MW x 2 [0.8, 1.5] sec
Result: Plasma.
D: ran. 5 faults
E: ran. clean.
J: ran. 2 faults.
-----------------------------------------------------------------------------
030 BT = 5.4 T, nl04 = .8e20 m^-2, Ip = .8 MA, SNU
D: 1.1 MW [0.6, 1.5] sec
E: 1.0 MW, [0.6, 1.5] sec
J: 1.1 MW x 2 [0.8, 1.5] sec
result: Plasma.
D: ran. 7 faults
E: ran. clean.
J: ran. 2 faults.
-----------------------------------------------------------------------------
031 NTP
-----------------------------------------------------------------------------
032 NTP
-----------------------------------------------------------------------------
034 No plasma.



Entered: Jul 7 2004 03:49:34:413PM
Author: Unknown
Conditioning and cleanup with piggyback of MP 364 - 'Measurement of
wall pumping on Alcator C-Mod'

This mini-proposal has a number of interconnected goals all having
to do with the wall sources and sinks of neutrals. First we would
like to determine the role of the wall/limiters as a source of
neutrals during RF power injection. The role of boronization in
affecting the wall pumping/sources will be addressed. Understanding
the processes involved will help us better control the plasma
density (better understand the utility of the cryopump) and perhaps
the H/D ratio. A further goal is to understand the scaling of
pumping processes to enable prediction of the T stored in a
high-Z first-wall in a BPX w/B in the vessel.

Summary of results:
1031104 was spent collecting background data while RF
conditioning was occurring. We kept the gate valve closed for
8 minutes after the shot in order to fit the long time scale
equilibration of the vessel pressure. This was done from shot 7
on. We had previously utilized one 20 minute gate valve closure to
best measure the long e-folding time. The amount of gas puffed into
the machine was measured utilizing the "Goetz' calibrated plenums.
The pressure in the machine was made using the barotron gauges,
which are absolutely calibrated. We found that in general, for this day, the walls pumped
during the shots; there was less gas in the machine after the shot
than put in during the shot. As usual the this effect was reversed
when disruptions occurred. The H/D ratio steadily rose during the
day from 5% to 20%.

Physics Operator Summaries
Entered: Jul 7 2004 04:37:19:613PM
Author: Steve Wolfe
Physics Operator Summary for Tuesday, Nov 4, 2003


Conditioning and Clean-up
SL:none
PO:wolfe
EO:Cochran,Fitzgerald,Byford,Parkin

The plan was to run upper null discharges to continue the cleanup and
conditioning process in preparation for upper and double null operations,
while bringing up the RF power. The RF'ers also wanted to test the new
transmission line transformers, which are supposed to improve matching and
reduce the voltage. Bruce requested long gate valve closures (8 minutes) to
monitor the gas evolution and determine wall pumping.

We started with a series of cycle tests as Josh continued trying to debug the
dispatcher problems under RH9. Prior to the run, Josh had returned the cpci
data acquisition systems to their previous mode of operation, and fixed a
network problem with the magnetics cpci crate.

First plasma attempt was shot #5, which had seg2 imported from 1031017009, an
upper null 800kA shot; this ran, but the cpci's, which had been working on test
shots, failed so there was no magnetics data. Shot 6 fizzled but got magnetics
and rf data. From there, we struggled on. All discharges were upper null
(those that ran) with only a few minor tweaks to density and the current
rise. There were a couple more data system glitches, e.g. the first try at
shot 15, but by the end of the day Tom and Josh seemed to have gotten the
cycle to hold together. Josh also claims to have fixed a bug in the cpci setup
which caused it to fail on shots 22 and 24.

There were a high fraction of fizzles and a few duds. Tweaks by the physop
were ineffective. I tried changing the pre-puff, the ef4 current (by 10A) and
Br0. On shot 30 I asked for the EFC start to be moved from -.035 to -.05, to
try to get early zcur feedback. However, it wasn't until shot34 that I found
that the wire 3 controller with the chopper turned on had been set to .03
seconds, so only pre-program was going out. In any case, it didn't help, as
all of 31-34 were duds or fizzles.

Despite the poor startup reliability, we did accomplish some of what we
wanted. The RF got up to 5MW with reasonable pulse lengths, and demonstrated
some success with the two new transformers in the D-port transmission
line. They concluded that one of the slugs was mispositioned by 3" and will
recalcualte and modify the setup accordingly. Bruce was monitoring the gas
inventory all day (gate valves closed for 8minutes from shot7 on). The H/D at
high RF power was running in the 15-24% range, having started around 4% with
low/no RF; there was no indication the H/D was coming down despite putting
lots of joules on the upper strike area.

Scorecard
-----------

Tests/No power cycles 4
Duds 4
Fizzles 10
Plasmas 16
========= ==
Shots 34







Session Leader Comments

Physics Operator Comments
Nov 4 2003 07:17:02:153AMSteve WolfeSetting up for upper null discharge to clean up upper strike area.

Import seg2 from 1031017009
Load/clean: get a factor message on zcur, and wirename warning on p09,P13 in seg2
touch the wires and reload; still warns on p13, maybe I touched the wrong one.
Do it again, and this time it completes with no warnings
Nov 4 2003 07:20:49:047AMSteve WolfeTHere were serious problems with the cycle tests yesterday.
Tom has advised that it should work with some "nursing along" today.
This seems to be a consequence of the "upgrade" to RH9.

In a possibly unrelated problem, the cpci digitizers are not booting or
communicating. Josh hopes to have these working again this morning. We need
the magnetics cpci to run.
Nov 4 2003 07:58:07:403AMSteve WolfeJosh found that the network connection to pcdaqmhd1 had a button pushed that
shouldn't have been. After making it look like all the others, we were able
to reboot pcdaqmhd1 and then pcdaqrf2 under the "old" scheme.

He is changing the trees to use this configuration. We will want to run a cycle test
but it might just work.
Nov 4 2003 08:24:19:650AM1031104001Steve WolfeShot#1 - data system cycle for Josh to check out everything
Hangs in init.
Not quite ready for prime time.
Nov 4 2003 08:43:55:163AM1031104001Steve WolfeShot#1 - Trying again - no joy
Next jas will blow away the dispatcher and try again
Nov 4 2003 08:54:28:307AM1031104002Steve WolfeShot#2 - gettting farther this time, but no magnetics data.
Tree setup was apparently wrong, looking for pcdaqmhd2 instead of 1

Made it through store, but didn't update the big board (in init or store)
Nov 4 2003 09:05:29:390AM1031104003Steve WolfeShot#3: Getting better- big board updated and magnetics came through.

made it thrtough recool
Nov 4 2003 09:21:10:757AM1031104003Steve WolfeShot#4: Go for it!
We are having a delay to check a TF scanner reading.
Nov 4 2003 09:37:14:417AM1031104004Steve WolfeShot#4: Go for it!
Cycle hung in init. camac3 server died (according to jas)

open breakers and do another no-power cycle
Nov 4 2003 10:05:03:367AM1031104005Steve WolfeShot#5: Try for plasma again after jas changed an envar.
plasma full length looked upper null on TV

No magnetics data. looks like it didn't get triggered?
No rf data either.

Lots of missing data, some scopes not working.
ECE seems to be flatlined.
Nov 4 2003 10:32:51:283AM1031104006Steve WolfeShot#6: A test shot of magnetics worked, but it uses do/method
Josh doesn't know why it didn't work on shot 5, suggests we try again

fizzle. Not surprising. Got magneitcs data this time.
Looks like a bouncer?

next shot: br0 from .0005 to .001
Nov 4 2003 10:52:00:837AM1031104007Steve WolfeShot#7: change br0 from .0005 to .001
Set turbo valve closure to 8 minutes instead of 2 (missed communication with engineering
on first shots.)

plasma, full length. Looks like a good upper null in EFIT.
Over 3MW of rf, no H-mode.
H/D from .04 to .08
startup looks ok, but I'm going to drop the gas anyway.
Nov 4 2003 11:06:02:670AM1031104008Steve WolfeShot#8: drop pg4 from 23->20msec
fizzle. Still looks to me like moving in, very low current

maybe another br tweak
Nov 4 2003 11:19:50:317AM1031104009Steve WolfeShot#9: br0 from .001 to .0015
dud. It gave me the br I asked for, but I guess it doesn't like it.

next shot: br0 back to .001
Nov 4 2003 11:36:13:340AM1031104010Steve WolfeShot#10: br0 back to .001
plasma, full length. This startup looks good.
RF not as happy on this shot.

I'm tempted to move the EFC start to -.05 to get early zcur control,
but leave it alone for now. Give JR more Ar on next shot.
Nov 4 2003 11:48:28:873AM1031104011Steve WolfeShot#11: pg1 from 25 to 35msec (Ar)
plasma disrupts in rampdown at 1,7sec.
startup tried to move in, but survived ok
H/D starts around .04 and rises to .08
density is a little higher on this one; blip is puffing He from the NINJA.

next shot: no changes

Nov 4 2003 11:58:37:550AM1031104012Steve WolfeShot#12: no changes
plasma disrupts at 1.7sec
RF up to 3.4MW, D a little better this time.

next shot: drop density for Wookie
Nov 4 2003 12:14:00:587PM1031104013Steve WolfeShot#13: nl04 from 1e20 to 0.8e20
plasma to 1.86sec
early density came down, still rising with RF later
small residual marfe on Dalpha around .4 to .5sec, near crossover
D stays on with some faulting, E and J are steady.
H/D up to 20% during RF

next shot: no changes
Nov 4 2003 12:24:23:467PM1031104014Steve WolfeShot#14: no changes
fizzle. moving in I think.

next shot: no change, let it come back on its own
Nov 4 2003 12:36:20:957PM1031104015Steve WolfeShot#15: no changes
cycle hung in init.
No power shot.
Nov 4 2003 01:00:15:137PM1031104015Steve WolfeShot#15: (second take at 15) no changes
plasma to 1.75sec
D and J have some faults, E steady, over 4MW at the max
H/D bouncing between 10 and 15%

next shot: No changes
Nov 4 2003 01:12:28:703PM1031104016Steve WolfeShot#16: No changes
fizzle, late breakdown at 12msec

next shot: no change
Nov 4 2003 01:26:13:973PM1031104017Steve WolfeShot#17: No changes
plasma to 1.78sec
D and J still ragged, max power 4.4MW

next shot: no changes
Nov 4 2003 01:41:56:403PM1031104018Steve WolfeShot#18: No changes
plasma to 1.8sec
J trips during pulse.

next shot: no changes
Nov 4 2003 01:49:31:763PM1031104019Steve WolfeShot#19: No changes
plasma to 1.8sec, J trips again.

next shot: tweak current rise in seg2
Nov 4 2003 02:04:52:147PM1031104020Steve WolfeShot#20: raise ip program at t=.1 from 450->550kA

plasma to 1.7sec, D and E stay on, J a few faults, max power 4.7MW

next shot: no changes
Nov 4 2003 02:20:04:090PM1031104021Steve WolfeShot#21: no changes

plasma to 1.75, J tripped again.
max power 4.95MW; H/D up to 24% at .93sec

next shot: no changes
Nov 4 2003 02:34:09:220PM1031104022Steve WolfeShot#22: no changes

fizzle. cycle seems to hang at the beginning of store.
Josh says the magnetics server got stuck; he freed it up, but
so far no magnetics data.

magnetics data restored, but no dependent actions happen.

next shot: no change
Nov 4 2003 02:48:25:473PM1031104023Steve WolfeShot#23: no changes

plasma to 1,74sec, up to 5.3MW but J and D have multiple faults.
nl4 feedback is getting rocked and causes a few bursts of gas,
very ragged density trace. Jim says it may be getting vibrated by
something.

next shot: slow down density rise a little.
Nov 4 2003 02:57:33:993PM1031104024Steve WolfeShot#24: slow down density rise a little.

plasma to 1.75 sec. No magnetics data again, this time it didn't hang the cycle.
The web page claims it took data, might be recoverable. Jas is typing at it.
Looks like I got rid of the marfe. D faulted out early; max power 3.8MW

next shot: no changes

Nov 4 2003 03:05:43:763PM1031104025Steve WolfeShot#25:no changes
fizzle. Based on previous results it will come back next shot

next shot: no changes
Nov 4 2003 03:21:50:143PM1031104026Steve WolfeShot#26:no changes
A dud!

next shot: raise pg4 to 24msec
Nov 4 2003 03:32:01:320PM1031104027Steve WolfeShot#27: raise pg4 to 24msec
fizzle. got to 60kA, no bounce.

next shot: ef4 more negative by 10A
Nov 4 2003 03:47:18:357PM1031104028Steve WolfeShot#28: ef4 from -1320 -> -1330

plasma (finally!) to 1.78 sec
prf up to 5MW, H/D around 18%

next shot: no changes
Nov 4 2003 03:55:13:627PM1031104029Steve WolfeShot#29: no changes
fizzle

next shot: ef4 back to -1320
Nov 4 2003 04:11:15:443PM1031104030Steve WolfeShot#30: ef4 back to -1320
Move efc start time to -.05 from -.035 to get earlier fast zcur feedback.

plasma, to 1.8sec
Startup seems to hang inside for a while, then moves out.
It's not obvious that the chopper comes on any earlier.
4.9MW or so.

next shot: pg4 to 20msec


Nov 4 2003 04:21:04:277PM1031104031Steve WolfeShot#31: pg4 back down to 20msec
fizzle. gets to 50kA, moving up fast, but no evidence the chopper is coming on any earlier

next shot: drop early chopper program voltage


Nov 4 2003 04:35:53:367PM1031104032Steve WolfeShot#32: drop chopper program voltage at .02sec from 800 to 500
fizzle
I see no indication that the chopper timing has changed at all.

next shot: try dropping the gas further
Nov 4 2003 04:47:18:590PM1031104033Steve WolfeShot#33: try dropping the gas further to 18msec

The reason the chopper zcur feedback isn't coming on earlier is that
the controller doesn't come on until .03 sec.

dud, dropped the gas too far?

next shot: turn wire 3 controller on at 0.00, put chopper voltage back to 800 at .02sec
raise gas to 22msec
Nov 4 2003 05:01:47:750PM1031104034Steve WolfeShot#34: turn wire 3 controller on at 0.00, put chopper voltage back to 800 at .02sec
raise pg4 gas to 22msec. request gate valve closed until 20minutes after shot for blip

dud! It does look like the chopper feedback started earlier, but nothing to feedback on.
Bz is a bit too positive, but I don't understand why it was a dud.
That's all for today. Bob's problem tomorrow.

Engineering Operator Comments
ShotTimeTypeStatusComment
108:15:11:097AMTestBad
208:45:31:227AMTestOkShot cycle test
308:57:53:717AMTestOkShot cycle
409:31:04:900AMTestBad
509:56:54:643AMPlasmaOk
610:26:12:250AMPlasmaOk
710:43:17:723AMPlasmaOk
811:01:01:327AMPlasmaOk
911:14:43:020AMPlasmaOk
1011:27:52:570AMPlasmaOk
1111:40:46:467AMPlasmaOk
1211:53:28:597AMPlasmaOk
1312:06:06:787PMPlasmaOk
1412:19:03:637PMPlasmaOk
1512:32:00:030PMPlasmaOk
1601:04:36:293PMPlasmaOk
1701:17:29:160PMPlasmaOk
1801:29:48:273PMPlasmaOk
1901:42:12:823PMPlasmaOk
2001:54:44:657PMPlasmaOk
2102:11:50:523PMPlasmaOk
2202:24:24:530PMPlasmaOk
2302:36:46:737PMPlasmaOk
2402:49:07:273PMPlasmaOk
2503:01:36:823PMPlasmaOk
2603:14:02:267PMPlasmaOk
2703:26:24:380PMPlasmaOk
2803:38:51:620PMPlasmaOk
2903:51:33:093PMPlasmaOk
3004:04:13:503PMPlasmaOk
3104:16:34:633PMPlasmaOk
3204:28:50:797PMPlasmaOk
3304:41:30:257PMPlasmaOk
3404:54:31:340PMPlasmaOk