Alcator C-Mod Run 1040415 Information

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Miniproposals
Miniproposal:389
Date Filed: 2/5/2004
Title:CNPA Testing and Calibration
First Author:Vincent Tang
Session Leader:Vincent Tang (shots 1-30)

Operators
Session leader(s):Vincent Tang
Physics operator(s):Ron Parker
Engineering operator(s): Unknown

Engineering Operator Run Comment
MP#389 Compact Neutral Particle Analyzer (CNPA) Testing SL:Tang PO:Parke

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:04:867PM
Author: Vincent Tang
Run Summary:

The machine performed well today and we took a lot of data. We were able to
run a RF(shots 13, 14, 15, 16) and field scan(shots 17, 18,19,20) for
nl_04~.4e20. It appears that the detector received the most signal at 5.4T,
and, as expected, is sensitive to changes in RF. However, we could not
prevent H modes when the power exceeded ~1.3MW; the rise in density coupled
with the rapid increase in photon background deteriorated the signal.
Limiter runs could potentially solved this issue. Finally, for the last few
shots(#27-30) we were able to do parts of a density scan at 1-1.5 MW from
nl_04~0.4e20 to 0.8e20; the neutral energy and count rate lowered as
expected when the density increased.

It was a challenge to anticipate the proper aperture size, requiring some
shots to be repeated. Finally, the particle/photon filter test was
convincing but not absolutely conclusive due to possible scattering of
neutrals around the CNPA filter wheel.

More detailed analysis of the data is required to study the minority tails.
All in all, this run day provided us with significant information for
improving the diagnostic, and potentially some very interesting plasma
behavior.


____________________________________________________________________________
__________________________________
Engineering Setup and Run Plan 1040415

ECDC overnight in D2 @ 2e-4 Torr stopping at 07:00

Run begins at 09:00 and ends at 17:00

Purpose: MP#389 Compact Neutral Particle Analyzer (CNPA) Testing
Session leader: Tang

Physop: Parker

Engineering Setup:

Power Supplies as on 1040414013

A-Coil power supplies off.

Gas System Setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar Hybrid enabled (PG1)
leave B-side upper as is Hybrid DISABLED (PG2)
fill C-side with 30 psi D2 Hybrid enabled (PG3)


Diagnostic gate valve permissives for ECE, VUV, DNB assuming no vacuum
problems

Disable NINJA

RF: Transmitters #1-4 in RUN-ON by 08:30

Objectives:

The main objective of this proposal is to verify the operational status
of the CNPA,characterize its operational range, and study ICRF tails.
The first few shots will confirm that the previously recorded CNPA
signals are indeed caused by particles,not photons, by inserting a 10
micron Be filter.Afterwards, a power scan based on shot 1040414013
starting at 0.5 MW will be performed. We will stop raising the power
when H-Modes are triggered. The CNPA aperture will be adjusted with cell
access as needed. With success, we will carry out a density scan and
attempt to fill in the power vs. density operational range. Finally,
time or interest permitting, we will do a limited field scan and/or
change the phase of the antenna to study the effecton the minrity heated
tails.

Run Plan:

1. Reproduce shot 1040414013 and confirm increase of signal (counts and
energy)during DNB.

2. Repeat with 10 micron Be filter.

3. Power scan starting at 0.5 MW until H-modes are reached.

4. Repeat 3) at the folowing densities:

nl_04=6e19 m-2, 8e19 m-2, 1e20 e-2

5. Based on success on the above scans, shoose a suitable density and
power, and carry out a field scan with selected values between 4.7 T to
6.0 T. If time,vary antenna phasing.


Physics Operator Summaries
Entered: Jul 7 2004 04:36:49:880PM
Author: Ron Parker
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Run Summary 1040415

The run was devoted to checking out the performance of the Compact Neutral Particle Analyzer (CNPA).Most of the shots were at low density, typically nl_04 ~ 0.4e20 m-3. The RF power was kept reasonably low, e.g., 1 MW to avoid H-modes.

The machine performed very well for this run and good data were obtained. The main result from the CNPA was that a energetic neutral tail was apparently observed, but energetically softens rapidly as density is increased. Raising power leads to H-modes and high density, but that produces low energy particles/photons that tend to saturate the detector.But even with this background, very few high energy counts were obtained, leading to a possible conclusion that energetic tails do not form above nl_04 =8e20 m-2 and 1 MW of power.But this needs to be checked more carefully by running limiter discharges.

The discharges were very reproducible and the machine ran exceptionally well. Of 30 shots, 2 were test shots after power glitches, one shot disrupted and the rest ran exactly as programmed. There were no duds and no fizzles, thanks to excellent skill of the physics operator (and the support team!)


Engineering Setup and Run Plan 1040415

ECDC overnight in D2 @ 2e-4 Torr stopping at 07:00

Run begins at 09:00 and ends at 17:00

Purpose: MP#389 Compact Neutral Particle Analyzer (CNPA) Testing
Session leader: Tang

Physop: Parker

Engineering Setup:

Power Supplies as on 1040414013

A-Coil power supplies off.

Gas System Setup:
fill B-Top with 6 psi D2 Hybrid enabled (PG4)
fill B-side lower with 1 psi Ar Hybrid enabled (PG1)
leave B-side upper as is Hybrid DISABLED (PG2)
fill C-side with 30 psi D2 Hybrid enabled (PG3)


Diagnostic gate valve permissives for ECE, VUV, DNB assuming no vacuum
problems

Disable NINJA

RF: Transmitters #1-4 in RUN-ON by 08:30

Objectives:

The main objective of this proposal is to verify the operational status of the CNPA,characterize its operational range, and study ICRF tails. The first few shots will confirm that the previously recorded CNPA signals are indeed caused by particles,not photons, by inserting a 10 micron Be filter.Afterwards, a power scan based on shot 1040414013 starting at 0.5 MW will be performed. We will stop raising the power when H-Modes are triggered. The CNPA aperture will be adjusted with cell access as needed. With success, we will carry out a density scan and attempt to fill in the power vs. density operational range. Finally, time or interest permitting, we will do a limited field scan and/or change the phase of the antenna to study the effecton the minrity heated tails.

Run Plan:

1. Reproduce shot 1040414013 and confirm increase of signal (counts and energy)during DNB.

2. Repeat with 10 micron Be filter.

3. Power scan starting at 0.5 MW until H-modes are reached.

4. Repeat 3) at the folowing densities:

nl_04=6e19 m-2, 8e19 m-2, 1e20 e-2

5. Based on success on the above scans, shoose a suitable density and power, and carry out a field scan with selected values between 4.7 T to 6.0 T. If time,vary antenna phasing.








Session Leader Comments
Apr 15 2004 09:09:57:713AM1040415001Vincent TangTF test
Apr 15 2004 10:15:29:147AM1040415004Vincent TangGood shot, strong signal during RF with more counts during DNB period
Apr 15 2004 10:40:27:190AM1040415005Vincent TangGood shot. Even with the 10um Be filter, we got more counts during the DNB period. However, the rate is ~6 times less than w/o the filter.

Apr 15 2004 01:00:41:473PM1040415006Vincent Tang10um filter removed, and aperature opened to 3.20/45.
Counts above 30keV the 50ms before, during, and after the DNB pulse are 564, 2466, and 528
Apr 15 2004 01:01:28:643PM1040415007Vincent Tang10um filter reinstalled.
Counts above 30keV the 50ms before, during, and after the DNB pulse are 60,292,113
Apr 15 2004 01:03:50:033PM1040415008Vincent TangFilter wheel turned to 1/16"SS304 to test scattering theory.
Shot disrupted but the beam fired...CNPA picked it up but only a bit--
would support theory that the neturals are scattering around the
filter wheel
Apr 15 2004 01:06:01:127PM1040415009Vincent TangLots of HXrays...HXR signal is enchanced during the beam.
Apr 15 2004 01:18:07:443PM1040415009Vincent TangLots of HXrays...HXR signal is enchanced during the beam. A puzzle.
Apr 15 2004 01:18:45:880PM1040415010Vincent TangDNB didn't fire. no signal except for RF background
Apr 15 2004 01:19:51:490PM1040415011Vincent TangAgain lots of HXR, although this time there as no significant enchantment during the beam period, as in shot 9.
Apr 15 2004 01:30:06:607PM1040415013Vincent TangStart RF scan. No filter. Counts above 30keV 50ms before, during, and after DNB is 2057,3486,1981.
Spectrum is harder than at 1MW
Apr 15 2004 01:30:43:153PM1040415014Vincent TangStart RF scan. No filter. Counts above 30keV 50ms before, during, and after DNB is 536,1724,703
Apr 15 2004 01:31:46:137PM1040415015Vincent Tang2MW; aperature opened too wide; overloaded Amp.
Apr 15 2004 02:12:15:810PM1040415016Vincent TangReduced aperature for possible H-mode. Counts are 106.187,121
Apr 15 2004 01:56:05:883PM1040415017Vincent TangField change to 4.8T in order to test field sensitivity
Apr 15 2004 02:44:54:627PM1040415019Vincent TangUnable to reproduce shot 6 in terms of CNPA signal.
Apr 15 2004 03:42:26:863PM1040415024Vincent Tangwe are repeating shots 22 and 23 in reverse order since the field was at 6T not 5.4T. So shots 24 will have the
aperature closed, while shots 25 will try to reproduce shot 6.
Apr 15 2004 04:09:21:110PM1040415025Vincent Tangwe have reproduced shot 6. Now we will start on the density scan
Apr 15 2004 04:22:58:880PM1040415026Vincent TangCNPA spectrum is softer relative to shot 25. Good data.
Apr 15 2004 04:49:46:047PM1040415028Vincent TangPlasma went into H-mode and overloaded amp system. Next shot will be a repeat with the aperature reduced by half.
Apr 15 2004 05:17:24:743PM1040415030Vincent TangNo significant CNPA signal

Physics Operator Comments
Apr 15 2004 08:49:18:903AM1040415001Ron ParkerFirst shot will be a 50 kA test shot.
Apr 15 2004 09:15:15:663AM1040415001Ron ParkerTest shot was fine, next shot will be a plasma shot, hopefully replicating 1040414013.
Apr 15 2004 09:32:19:697AM1040415002Ron ParkerShot 2 had a glitch in the timing. The shot ran fine, but the beam did not fire
at the set time. Other than that, a good shot.
Apr 15 2004 09:47:54:123AM1040415002Ron ParkerThere was a commutation fault on shot 2 and a TF fuse blew. Replacing the fuse took
20 minutes and will require a 50 kA test shot on shot 3.
Apr 15 2004 09:55:53:630AM1040415003Ron Parkershot 3, a 50 kA test shot looked OK. Next shot should be a plasma shot.
Apr 15 2004 10:40:06:753AM1040415004Ron ParkerShot 4 ran well, data collected.
Apr 15 2004 10:40:21:893AM1040415005Ron ParkerShot 5 ran well, filter in place.
Apr 15 2004 10:51:05:353AM1040415006Ron ParkerShot 6 ran well. Aperture wider, more counts.
Next shot, insert filter.
Apr 15 2004 11:12:40:493AM1040415007Ron ParkerShot 7 ran well, filter in place.
Nest shot: same plasma, thicker filter.
Apr 15 2004 11:16:12:430AM1040415008Ron ParkerShot 8 disrupted. Repeat on next shot.
Apr 15 2004 11:27:49:030AM1040415008Ron ParkerOops, power glitch. short delay.
Apr 15 2004 11:44:35:703AM1040415009Ron ParkerShot 9 ran OK, but strong hard X-rays.
Apr 15 2004 12:11:29:200PM1040415010Ron ParkerShot 10 was OK, no beam.
Apr 15 2004 12:10:31:903PM1040415011Ron ParkerShot 11 went off OK, fairly strong hard X-rays.
Apr 15 2004 12:26:40:093PM1040415011Ron ParkerShot 11 OK, but hards too strong.
Shot 12: inject gas at 175 ms to reduce hards.
Apr 15 2004 12:47:52:843PM1040415013Ron ParkerShot 12 was OK. Hards were less.

Next shot: Double gas and RF to 1.5 MW
Apr 15 2004 01:04:27:720PM1040415014Ron ParkerJ. Snipes taking over for R. Parker as physop. Increased Pulse gas 3 in segment 1 to 100 V at 0.05 s and 75 V
at 0.11 s. Shot 14 was O.K.

Apr 15 2004 01:44:19:313PM1040415015Ron ParkerIncreased PG3 to 100 V also at 0.11 s for shot 15.
Apr 15 2004 02:21:32:583PM1040415016Ron ParkerReduced TF current to 133 kA for shot 17.
Apr 15 2004 02:23:02:003PM1040415017Ron ParkerIncreased field to 5.26 T for shot 18
Apr 15 2004 02:25:54:923PM1040415018Ron ParkerShot 18 ran OK. Next shot: back to 150 kA TF current.
Apr 15 2004 02:44:19:630PM1040415019Ron ParkerSnot 19 was fine. for shot 20, raise field to 5.8
Apr 15 2004 02:56:23:103PM1040415020Ron ParkerShot 20 went off well. Next: 6.0 T
Apr 15 2004 03:05:28:517PM1040415021Ron ParkerShot 21 OK. Next: Back to reproduce shot 6
Apr 15 2004 03:41:06:210PM1040415022Ron ParkerShot 22 ran well, but CNPA signal did not reproduce. Why? Oops,
Shot 6 did not load!
Next: Same shot with aperture closed.
Apr 15 2004 03:42:13:067PM1040415023Ron ParkerShot 23 ran, but field was 5.9 T since shot 6 did not load in last shot.
Next: repeat, this time at 5.4 T
Apr 15 2004 03:57:19:620PM1040415024Ron ParkerShot 24 went of well and reproduced shot 6, except more hard X-rays (no early gas pulse).

Next: reload shot 22, but set field at 5.4 T
Apr 15 2004 04:11:29:013PM1040415025Ron ParkerShot 25 reproduced shot 6 and also reproduced CNPA signal.

Next: raise density to nl_04=0.4e20
Apr 15 2004 04:23:15:613PM1040415026Ron ParkerShot ran nicely with density at ~ 0.4 (nl_04).

Next: raise nl_04 to 0.5 m-2
Apr 15 2004 04:35:13:043PM1040415027Ron ParkerShot 27 ran well with increased density, fewer high energy CNPA counts.

Next shot: raise RF power to 1.5 MW
Apr 15 2004 05:13:16:607PM1040415028Ron ParkerShot was OK, but ran into H-mode and cutoff CNPA.
Next: reduced aperture in CNPA, same shot.
Apr 15 2004 05:14:23:527PM1040415029Ron ParkerShot 29 was OK, but H-mode again and saturated detector.
Apr 15 2004 05:15:05:293PM1040415030Ron ParkerShot 30 ran well, but H-mode even at 1.35 MW. Very few fast particles.

Engineering Operator Comments
ShotTimeTypeStatusComment
109:04:11:923AMTestOk50KA Test Shot
209:17:05:570AMTestOk
309:50:07:310AMTestOk50KA TF Shot
410:02:27:470AMPlasmaOk
510:19:47:283AMPlasmaOk
610:40:35:207AMPlasmaOk
710:57:40:350AMPlasmaOk
811:13:53:447AMPlasmaOk
911:38:51:363AMPlasmaOk
1011:53:48:197AMPlasmaOk
1112:06:07:953PMPlasmaOk
1212:26:00:827PMPlasmaOk
1312:46:58:437PMPlasmaOk
1412:59:43:693PMPlasmaOk
1501:17:33:930PMPlasmaOk
1601:35:16:773PMPlasmaOk
1701:57:21:743PMPlasmaOk
1802:11:16:543PMPlasmaOk
1902:31:09:763PMPlasmaOk
2002:44:38:550PMPlasmaOk
2102:57:09:710PMPlasmaOk
2203:17:15:103PMPlasmaOk
2303:30:22:500PMPlasmaOk
2403:44:28:270PMPlasmaOk
2504:00:46:020PMPlasmaOk
2604:13:18:920PMPlasmaOk
2704:26:17:033PMPlasmaOk
2804:39:01:070PMPlasmaOk
2904:52:17:340PMPlasmaOk
3005:04:48:503PMPlasmaOk