Alcator C-Mod Run 990202 Information

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Miniproposals
Miniproposal:207
Date Filed: 1/4/1999
Title:Constant shots to check vertical alignment of ECE
First Author:Amanda Hubbard
Session Leader:Amanda Hubbard (shots 1-26)

Operators
Session leader(s):Amanda Hubbard
Physics operator(s):Steve Wolfe
Engineering operator(s):Gary Dekow,Frank Silva

Engineering Operator Run Comment
MP #207 ECE Alignment/Hubbard/Wolfe,Irby/Silva

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:18:773PM
Author: To Be Determined
Session leaders report for 2/2/99

Session leader: Amanda Hubbard
Physics operators: Steve Wolfe and Jim Irby

This run was in support of MP 207, ECE beamline alignment.


Run Plan:
The plan is to obtain, and keep repeating, reproducible 800 kA plasma.
The ECE beamline will be scanned vertically on a shot to shot basis,
out to at least the sawtooth inversion radius. This will enable us
to check the true center position.

Result:
This was carried out much according to plan, amazingly enough for a
Tuesday so early in the campaign. By shot 6 the operators had achieved
a full length, 800 kA plasma suitable for the alignment. These were
then repeated on most discharges throughout the day, thanks perhaps to
between-shot ECDC. There were some minor variations in density, which
affected the temperature. Thomson was running all day which should allow
us to correct for this.

The shots on which the ECE beam was scanned are the following:

shot Zbeam comment

6 0 cm on-axis
7 - 7 cm just inside sawtooth inversion radius
8 -9 cm just outside sawtooth inversion radius
9 +7 cm just inside sawtooth inversion radius
10 +8 cm at sawtooth inversion radius
13 -8 cm at sawtooth inversion radius
14 -2 cm close to axis
15 0 cm on-axis
16 +2 cm close to axis
17 +12 cm in gradient region
18 -12 cm in gradient region
19+ 0 cm on axis

Users of ECE signals should be aware that as we were scanning, on most shots
the ECE temperature profile was NOT through the horizontal midplane.
(This affects the Michelson, GPC and GPC2). Thomson was
of course unaffected. The vertical
position is stored in node \ELECTRONS::ECE_ZBEAM, and noted in the logbook.
Based on the inversion radii, we can say that our initial estimate of the
position was in fact very close to correct. More cross-checks will be
done based on absolute temperature.

Having obtained the requisite 10+ reproducible shots, and achieved the
goal of the MP, the run was turned over to other commissioning experiments,
including HIREX cross-calibration, RF coupling (power progressively ramped
up shot to shot, but no heating observed), and a first (successful!)
exercise of the flappers (Shots 22, 24) which raised ne considerably
but did not cause disruption. See PHYSOP summary and various logbook
entry for details. All in all, a very successful commissioning run -
thanks Steve, Jim and engineering crew!


Physics Operator Summaries
Entered: Jul 7 2004 04:36:59:957PM
Author: To Be Determined
Physics Operator Summary for Tuesday, Feb 2, 1999

MP: 207 ECE Alignment
SL: Hubbard
PO: wolfe Asst. PO: Irby
EO: Silva,Dekow

This run was in suppport of MP#207, ECE alignment. The requirement was for 10
reproducible shots to be run while the ECE beamline is scanned vertically
shot-to-shot to determine the proper alignment. The goals of this run were
accomplished. Piggybacking was done by HIREX, flappers, and the ICRF. The run
is also considered part of the cleanup campaign.

We started from the diverted discharge 990129017 which was run at the end of
last Friday's run, with the current raised to 800kA. Some tweaks were required
to get a current rise. Once we got past the fizzles, the current rise was
found to be very fast. It probably would have been a good idea to slow it down
and speed up the Bz ramp rate, but we wanted to get on with it, and the
existing startup was found to be reasonably robust, at least with between-shot
ECDC. We ran typically 5 minutes of He ECDC between shots all day; ECDC
pressure was 5e-5 (gauge).

The machine ran well today, except for several shots which came to an untimely
end due to injections. John Rice identified most of these, and the
non-terminal injections, as Mo.

The TCI had problems today. After shot 12 we changed to NL_ZMETER feedback,
which was satisfactory but not great, since raising the density made Z go down
and reduced the response. Still it was better than random fringe jumps. For
future reference, the procedure was as follows: LOAD_WIRE from 980211016,
seg#2, wire 14, into segment#2, wire 14. Adjust the waveform to match what we
got on a good shot from the sequence, in this case 0.4V, later increased to
0.5V. I got several complaints that the waveform had been renamed since it was
drawn, even after moving points around; eventually these stopped. Probably
there is a bug in this part of the PCS code. In any case it worked. Gain was
5, predictor is -1.0 on zmeter, controller on pg3 is 50, all untouched from
980211016.

Several tasks were accomplished today. Amanda confirmed the ECE alignment,
which was the main focus of the run. John Rice got part way through
cross-calibrating the HIREX channels (Ar was on from shot 9, and up to 25msec
on shot 11. RF was broiught up to 1.2MW (shot 26); the RF seems to raise the
H/D ratio considerably at this point. No heating was observed, consistent with
the high H fraction (always >.4, up to .7 with the RF). Spencer opened the
flappers during the shot, and observed substantial changes in divertor and
midplane pressure, and in the density (shot 23-24).

Attempts to fix the rampdown were unsuccessful. It basically goes into a fin
or marfe at around 1.3 sec no matter what I did with position or shape.

Power systems performed well today. There were a couple of power room accesses
to reset OH1 after disruptions, and that was it. Cooling was rather slow; late
in the run the Central Column cooling was increased and that seemed to help,
although the vessel temperature also began to plummet.

Shot summary:
-------------
1 Tuesday test
2-3 Fizzles, minor tweaks to br, ef4, gas
4-5 Short disruptions
6-10 good plasmas, Part of ECE scan
11 brick at .62sec
12 TCI killed it early
13-19 plasmas in scan; NL_ZMETER feedback
20 fizzle, following a long cell access
21 Br tweak, plasma
22 short disruption-injection
23-24 plasmas with flaps,RF
25 short disruption - injection
26 plasma - rf=1.2MW, Ar off for goetz, flaps closed.

Scorecard:
----------
Tests 1
Duds 0
Fizzles 3
Plasmas 22
====== ==
shots 26

Session Leader Comments
Feb 2 1999 10:27:25:513AMAmanda HubbardThis run is in support of MP 207, ECE beamline alignment.

The plan is to obtain, and keep repeating, reproducible 800 kA plasma.
The ECE beamline will be scanned vertically on a shot to shot basis,
out to at least the sawtooth inversion radius. This will enable us
to check the true center position.

Users of ECE signals should be aware that as we are scanning, on most shots
the ECE temperature profiles will not be through the horizontal midplane.
(This affects the Michelson, GPC and GPC2). Thomson is working and will
of course be unaffected. I will store our best estimate of the vertical
position in node \ELECTRONS::ECE_ZBEAM, and in the logbook. We won't know
this position accurately until the alignment is finished.
Feb 2 1999 10:30:20:623AM990202005Amanda HubbardThis shot is approaching what we need, but disrupts once we get to flat top.

ECE beamline is at nominal center (Z=0). nel ~ 7e19, 1.8 keV
Feb 2 1999 10:51:07:903AM990202006Amanda HubbardGood shot, makes it to 1.4 s. 800 kA, as requested.
nel~ 6.5e19, Te0 ~ 1.65 keV.

Count this as first shot of the scan, nominal z=0.

For next shot, go to z=-7 cm.
Feb 2 1999 11:10:42:937AM990202007Amanda HubbardAnother good shot. Z was nominal -7 cm. Nearly at sawtooth inversion radius, just 1-2
channels showing small positive sawteeth.

nel 7.4e19. YAG TE0 = 1.6 keV. GPC ~ 1.45 keV (off-axis)

For next shot, go to z=-9 cm.
Feb 2 1999 11:46:37:763AM990202008Amanda HubbardAnother good shot. Z was nominal -9 cm. At or slightly outside sawtooth inversion radius;
all channels have inverted or no sawteeth.


nel 7.0e19. YAG TE0 = 1.65 keV. GPC ~ 1.25 keV (off-axis)

For next shot, go to z=+7 cm.
Feb 2 1999 11:48:54:733AM990202009Amanda HubbardAnother good shot. Z was nominal +7 cm. Slightly inside upper sawtooth inversion radius;


nel 6.9e19. YAG TE0 = 1.45-1.65 keV. GPC ~ 1.45 keV (off-axis)

For next shot, go to z=+8 cm.
Feb 2 1999 12:15:38:857PM990202010Amanda HubbardAnother good shot. Z was nominal +8 cm. Just tangent to upper sawtooth inversion radius;


nel 7.419. YAG TE0 = 1.57 keV. GPC ~ 1.35 keV (off-axis)

For next shot, go to z=-8 cm.
Feb 2 1999 12:30:20:217PM990202011Amanda HubbardDisrupted 727 ms. Z was nominal -8 cm. Looks ~ tangent to lower sawtooth inversion radius;

nel 7.4 e19. YAG TE0 = 1.6 keV. GPC ~ 1.45 keV (off-axis)

Everything was oscillating somewhat, even before the 'brick' or whatever did the shot in.
Try this vertical position again.
Feb 2 1999 01:11:26:903PM990202013Amanda HubbardGot a full shot. Z was nominal -8 cm. Looks ~ tangent to lower sawtooth inversion radius;

nel 6.7 e19. (a bit on low side, using new VB feedback)
YAG TE0 = 1.7 keV. GPC ~ 1.39 keV (off-axis)

Go to - 2 cm for next shot.
Feb 2 1999 01:39:26:640PM990202014Amanda HubbardGot a full shot. Z was nominal -2 cm. Have regular sawteeth again.

nel 6.7 - 8.1 e19. (ramping up during shot)
YAG TE0 = 1.4 - 1.6 keV. GPC ~ 1.5 keV (slightly off-axis)

Go to Z=0 cm for next shot.
Feb 2 1999 01:56:41:653PM990202014Amanda HubbardGot a full shot. Z was nominal center. Have regular sawteeth again.

nel 7.1 - 8.0 e19. (ramping up during shot)
YAG TE0 = 1.5 - 1.35 keV. GPC ~ 1.6 keV

Go to Z=+2 cm for next shot.
Feb 2 1999 02:18:36:983PM990202016Amanda HubbardGot a full shot. Z was +2 cm . Have regular sawteeth again.

nel 7.1 e19.
YAG TE0 = 1.6 keV. GPC ~ 1.55 keV

Go to Z=+12 cm for next shot.
Feb 2 1999 02:33:23:717PM990202017Amanda HubbardGot a full shot. Z was +12 cm . Way off axis

nel higher, 8.2-9.7 e19.
YAG TE0 = 1.7 - 1.37 keV. GPC ~ 0.97 to 0.7 keV (off axis!)

Go to Z=-12 cm for next shot.
Feb 2 1999 02:54:32:750PM990202018Amanda HubbardGot a full shot. Z was -12 cm . Way off axis

nel higher, 7.5-10. e19.
YAG TE0 = 1.5 - 1.32 keV. GPC ~ 0.97 to 0.7 keV (off axis!)

Go to Z=0 cm for next shot.
We're done scanning
Feb 2 1999 03:09:31:450PM990202019Amanda HubbardGot a full shot. Z was 0 cm, ie on axis. We now believe this.

nel lower, 6.5-7.5 e19.

We're done scanning

Physics Operator Comments
Feb 2 1999 07:14:47:310AMSteve WolfeColdstart at 2-FEB-1999 07:14:03.17
all matrices respond
Feb 2 1999 07:16:52:950AMSteve WolfeRun Plan for Groun'hog Day 1999

MP #207 ECE Alignment
SL Hubbard
PO wolfe Asst. PO: Irby

Engineering setup
-----------------
Overnight ECDC in D2
Gas Setup:
B-top 6psi D2 Hybrid Enabled
B-side lower 1psi Ar NOT enabled
B-side upper --- He set up for between shot ECDC
C-side 30psi D2 Hybrid enabled


PPower systems set up as for 990129017.
TF under hybrid control.

Note: We will probably want to do between-shot ECDC in helium, as we did
last Friday, but using the B-side Upper valve instead of B-side Lower.

We will start the day with a Tuesday OH test.

Plasma
------
The MP calls for reproducible discharges of almost any flavor. We will start
from 990129017, but with the plasma current raised to 800kA; this should be very
similar to last year's fiducials. We may take a few shots to settle on a
reproducible-looking set of conditions.

RF may be firing in the later part of the flattop, if this doesn't interfere
with the reproducibility.

We will be evaluating the fizzliness and pump-down recovery times, and will
probably do some between shot ECDC in Helium.

Time and Session Leader permitting, I may try looking at the offsets on ZCUR
and other wires.

Feb 2 1999 07:23:53:857AMSteve WolfeFor shot 1:
Load from 990129017
Change current to 800000 (seg 2)
INcrease seg 1 pre-puff from 15msec to 18msec
LOAD/CLEAN Load at 2-Feb-1999 07:24:42.00


Feb 2 1999 08:58:43:233AM990202001Steve WolfeShot 1: Tuesday test at 08:58. Looks ok.
Feb 2 1999 09:16:51:420AM990202002Steve WolfeShot 2: First plasma attempt. Ef4's not quite balanced.
fizzle. bd at 6.8ms, CII=.014, br is positive.
Feb 2 1999 09:30:15:000AM990202003Steve WolfeShot 3: br from .003 to .002, pre-puff to 16ms
another fizzle! bd at 4.8msec, bouncer, 50KA. Looks like it moves out,.

Try a Bz tweak.
Feb 2 1999 09:54:51:607AM990202004Steve WolfeShot 4: IC_ef4 from -1300 to -1285. (note: early point was actually at -1305).
plasma - shorty 285msec, ip=600kA
bd at 5.3msec. Fast current rise. Gets to 550kA by 100msec
Feb 2 1999 10:24:10:077AM990202005Steve WolfeShot 5: ecdc between shots to 15min. (about 6min of ecdc).
adjust current rise program to call for 450Ka at .1sec in seg 2
raise pg3 in seg1
plasma - shorty, pulled a breaker.
disrupts at 425msec, halpha burst at .4

Try one more like this to see if it cleans up, then back off.
Feb 2 1999 10:49:30:263AM990202006Steve WolfeShot 6: recalculate predictor for RCUR in seg2 (inputs were stale).
plasma - longer this time. disrupts at 1.3sec.
JR reports hard xrays on this shot. Density is not real flat

Amanda is starting her scan.

Feb 2 1999 11:01:52:763AM990202007Steve WolfeShot 7: repeat. base=6.8e-7
plasma to 1.41sec, JR says not so many hard x-ray
No rf on this shot; they were supposed to fire at 1.0sec
Feb 2 1999 11:07:34:483AM990202007Steve WolfeShot 7: repeat. base=6.8e-7
plasma to 1.41sec, JR says not so many hard x-ray
No rf on this shot; they were supposed to fire at 1.0sec

Feb 2 1999 11:26:28:793AM990202008Steve WolfeShot 8: No changes. base=5.8e-7, 16minutes in recool
plasma to 1.37sec, TCI looking ratty.

Feb 2 1999 11:45:41:467AM990202009Steve WolfeShot 9: Enable Ar puff (bside lower) 13msec at .3sec . Will RF go this time? base=6.2e-7
plasma to 1.36s RF still not firing.

Try moving the x-points away on rampdown
Feb 2 1999 12:09:55:357PM990202010Steve WolfeShot 10: Move zxl down and ZXU up after 1.2 sec to fix rampdown.
Ar puff to 20msec.
plasma to 1.36sec. x-point changes didn't help

Next shot, 5msec more Ar for JR.
Feb 2 1999 12:26:53:733PM990202011Steve WolfeShot 11: Ar puff to 25msec.
disrupted early (.637sec). Something comes in at .62sec

Feb 2 1999 12:43:13:950PM990202012Steve WolfeShot 12: Leave the Ar at 25msec, try again.
shorty. TCI feedback ran amok.

Set up for VB feedback?
Feb 2 1999 01:05:54:467PM990202013Steve WolfeShot 13: LOAD_wire 14 from 980211016, which had nl_zmeter
change nl_zmeter program to 0.4, which is what it was on shot 10.

I keep getting the message name of P14 in seg 2 has changed since last drawn, which is not true.
I moved a point to be sure. This could be a bug.

plasma to 1.38sec, nl4=7e19 instead of 8e19.
RF got about 8kW on that shot.
Feb 2 1999 01:27:27:437PM990202014Steve WolfeShot 14: Increase NL_ZMETER from 0.4 to 0.5
plasma to 1.33sec
lots of injections.

RF gets to 20kW this time.
Feb 2 1999 01:50:52:857PM990202015Steve WolfeShot 15: repeat
plasma to 1.36sec
nl4 dies, nl6 has two plateaux
Feb 2 1999 02:06:15:513PM990202016Steve WolfeShot 16: No changes
plasma to 1.36sec
Feb 2 1999 02:33:03:590PM990202017Steve WolfeShot 17: Change clearin ramp-in rate from 5.8cm/.4sec to 3cm/.4sec after 1.2sec
RF on to 0.85sec

plasma to 1.36sec. No effect.
Rf to 100kW, nl4 lived and was higher that time. Z-meter signal is 0.4V.
I think we need to reduce nl_zmeter
Feb 2 1999 02:44:28:920PM990202018Steve WolfeShot 18: Bring CLEARIN in 8cm/.4sec, RCUR in 2cm over same time
plasma to 1.30sec. OK I can make it worse.
RF nearly to .2MW

Feb 2 1999 03:04:46:840PM990202019Steve WolfeShot 19: import seg2 from 990202016 (back where it was).
plasma to 1.36. Rf to .25MW
Feb 2 1999 03:41:58:840PM990202020Steve WolfeShot 20: Access for Goetz and a cast of thousands. 35 minutes since last shot.
Jim and Rick found a hose wedged on the interferometer box, and tweaked up the laser.

fizzle. bd at 10msec.
Feb 2 1999 03:54:33:483PM990202021Steve WolfeShot 21: Br0 from .002 to .0025
plasma to 1.36sec
RF gets .2+MW

Next shot, Spencer will fire flaps at 1.05sec
Feb 2 1999 04:14:37:140PM990202022Steve WolfeShot 22: Flaps at 1.05sec.
Short shot/only got to .43sec
something comes in at .35sec


Feb 2 1999 04:26:32:780PM990202023Steve WolfeShot 23: Try again.
plasma to 1.33sec, got bright on the tv
rf to .45MW, flapper effect seen on div pressure, main pressure. Also seen on Halpha
Feb 2 1999 04:42:03:077PM990202024Steve WolfeShot 24: RF on earlier.
plasma to 1.32
Rf to .6MW. Rf seems to increase H/D

Next shot, turn off Ar for J. Goetz, no flaps
Feb 2 1999 04:57:58:950PM990202025Steve WolfeShot 25: Ar disabled. No flaps. Baseline for Goetz RGA.
short shot. .38, something took a bite out of Ip at 0.2sec,
Feb 2 1999 05:32:23:170PM990202026Steve WolfeShot 26: try one more time.
plasma to 1.38sec
RF got 1.2MW. H/D goes up with RF to .7

Engineering Operator Comments
ShotTimeTypeStatusComment
108:56:33:217AMTestOkOH1,2 Test OK
209:11:16:607AMPlasmaOkno faults/fizzel
309:24:03:623AMPlasmaOkfizzle
409:41:22:543AMPlasmaOkno faults/plasma
510:06:31:873AMPlasmaOkOH1 self powered ckt fired /Plasma
610:34:14:717AMPlasmaOkno faults/plasma
710:55:26:420AMPlasmaOkno faults/plasma
811:14:20:500AMPlasmaOkno faults/plasma
911:34:58:293AMPlasmaOkno faults/plasma
1011:58:15:340AMPlasmaOkno faults/plasma
1112:16:45:170PMPlasmaOkno faults/ dud
1212:35:16:200PMPlasmaOkOH1 Self powered ckt. fired/dud
1312:59:02:857PMPlasmaOkno faults/plasma
1401:20:21:763PMPlasmaOkno faults/plasma
1501:42:50:750PMPlasmaOkNo Faults/plasma
1602:02:23:560PMPlasmaOkNo Faults/ plasma
1702:22:52:840PMPlasmaOkNo Faults / plasma
1802:40:50:340PMPlasmaOkNo Faults / Plasma
1902:58:49:590PMPlasmaOkNO Faults / Plasma
2003:36:40:780PMPlasmaOkNo Faults / No Plasma
2103:49:26:967PMPlasmaOkNo Faults / Plasma
2204:06:24:250PMPlasmaOkNo Faults
2304:20:29:280PMPlasmaOkNo Faults / Plasma
2404:34:21:170PMPlasmaOkNo Faults / Plasma
2504:50:17:437PMPlasmaOkNo Faults
2605:04:23:590PMPlasmaOkNO Faults / Plasma