Alcator C-Mod Run 950518 Information

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Miniproposals
Miniproposal:075
Date Filed: 1/8/1994
Title:\'q\' profile measurements using Lithium pellet ablation cloud imaging.
First Author:Darren Garnier
Session Leader:Darren Garnier (shots 1-36)

Operators
Session leader(s):Darren Garnier
Physics operator(s):Joseph Snipes
Engineering operator(s):Joe Daigle,Vinny Bertolino

Engineering Operator Run Comment
Li Pellet q-profiles

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:13:740PM
Author: To Be Determined
Session Leader Summary for Run 950518

EO: V. Bertolino/J. Daigle
PO: J. Snipes
SL: D. Garnier

MP #75: q Profile measurements with the LPI

The purpose of the run was to measure the internal magnetic
configuration of the plasma using the LPI with the polarimeter and
cigar detector. Although we had data acquistion problems on the
first few shots, (that were quickly debugged by Tom and then Josh),
we obtained lots of data with good signal levels. Very preliminary
analysis indicates that the data is reasonable and should be
reduceable to give q profiles. Thus, I declare this run a success.
During the run, we first varied the pellet timing in the
vanilla shot. Next we scannded the current up and down to
vary the q profiles. Also we preformed double pellet experiments
to show what effect the pellet has on the current density. Although
these experiments caused most of the disruption of the day, the
data gathered from these should be extremely useful in understanding
what happens after pellets (p-mode and PEP mode). Finally,
we tried few current ramps and injecting KCl doped pellets for
the HIREX. (The K probably caused the disruption after this
otherwise small pellet).

The shot by shot rundown was:

Shot 1: OH Test shot.

Shot 2: Reload vanilla 820 from last shot yesterday.
2 pellets at 600 and 800 msec. Spectrometer set at 6-181.
550V. Dud.

Shot 3: Again, yay plasma! Got both pellets. Problems in my
data acquisition. Oh no.

Shot 4: funny pellets and still no data.

Shot 5: Data! Two pellets fired, only one data because of j221 problems.

Shot 6: Moved polarizers and got calibration data. Makes shot 5 data
look ok on rough analysis.

Shot 7: pellet dust only.

Shot 8: Got pellet. Cigar data too (9:32 on tape).
(Double pellet.)

Shot 9: Trying multiple pellets. .4 .6 and .8 sec. Got 2. And data!
Disrupt at 1 sec. Moved spectrometer down 16 steps.

Shot 10: Try again. Got all 3.

Shot 11: Again, but no polarizers this time.

I declare the polarizer works! Now on to the physics. We begin
by filling in single pellet points for various times, then we'll do
a current scan.

Shot 12: try for pellet at .8 sec. Got fragments.

Shot 13: try again. Got pellet but disrupted. Large moly injection
before pellet.

Shot 14: Reduce current to 600 kA. Try the .6 and .8 pellets.
First pellet disrupted.

Shot 15: Pellet at .8 sec. Opps, no pellet, mea culpa: operator error.

Shot 16: Again. Pellet disupted.

Shot 17: 2 pellets time .4 and .6. Second pellet fraged. Snake on first
pellet.

Now we will change current to around 1MA. (Asking for 950 kA)
Density to 1.3 also.

Shot 18: 2 pellets .6 and .9.
Aborted pellets due to incorrect setup

Shot 19: Repeat with feeling. Frag first. Good pep.

Shot 20: Moved second pellet to 1.2 Got both.

Shot 21: Pellets at .5 and 1. Frag first. MHD after 2nd pellet.

Shot 22: Again but w/o polarizers. missing first again.

Up in current some more. 1.2MA Density = 1.4 Nl04

Shot 23: Big pellet and big disruption. Got good data though. :-)

Next shot we are cleaning up from our mess.

Shot 24: 800kA no pellet.

Shot 25: 1 MA pellet at .8. Good shot no disruption.

Done with current scan. Now we will do double pellet experiments.
(ie. pep mode q profiles and fast current changes).

Shot 26: 2 pellets. .6 and .7
Got them both, plasma dies at .8

Shot 27: 2 pellets .6 and 1.0 no polarizers
Got them.

Shot 28: 2 pellets .6 and .62 (second is small)

Joe forgot to go back to our meat and potatoes plasma. We'll try again
reloading shot 19.

Shot 29: missing .62 pellet.

Shot 30: also missing .62 pellet. Disruption

Shot 31: moved the pellets to .8 and .82. Got both pellets. Disruption

We are having halo current warnings and are droping the current to
compensate. 800kA and 1.0 nel4 (this morning).

Shot 32: pellets at .6 and .66. Got both pellets and another disruption.

Shot 33: attempt to get negative current densities with rapid
ramp down of current. Pellet at .8 sec.

Shot 34: Try for KCl doped lithium pellet. Didn't get pellet and plasma
disrupted due to inappropriate programming.

Shot 35: Got KCl doped small lithium pellet. Caused disruption.

Shot 36: 2 lithium pellets at .6 and .8. Still disrupted :-{


LPI Summary

55 pellets requested
12 missing or fragmented
____
78% reliablity. (LPI probably needs a little cleaning overhaul.)







Physics Operator Summaries
Entered: Jul 7 2004 04:36:54:440PM
Author: To Be Determined
LPI q Profile Measurements
Engineer in charge: Vince Bertolino
Physics Operator: Joseph Snipes
Session Leader: Darren Garnier

Setup from shot 950517024. Idea is to inject Li pellets to measure q
profiles for a variety of q values, where q will be varied by varying the
plasma current. There may also be some variation in the horizontal plasma
position.

It was a very good run, despite a large number of disruptions, some quite
severe in terms of the halo currents. However, recovery from the
disruptions was immediate. Good q profile data was obtained for several
conditions and Garnier may even be able to put it all together and
graduate! Except for a power supply fault on shot 2, the machine ran
very well.

Shot 1: OH1, OH2, and TF test shot. Resistance O.K.
2: Power supply fault. No plasma.
3: Good shot. Magnetics data corrupted. No EFIT. Li at 0.6
and 0.8 sec.
4: Good shot. Very small Li pellets at 0.6 and 0.8 sec.
5: Good shot. Li pellet at 0.6 sec.
6: Good shot. Li pellet at 0.6 sec.
7: Good shot. No pellet.
8: Good shot. Li pellet at 0.6 sec, TCI lost fringes.
9: Good shot. Li pellets at 0.4 and 0.8 sec caused TCI to
lose fringes at 0.8 sec. Disrupted at 1.0 sec. Large MHD
after 1st pellet.
10: Good shot. Li pellets at 0.4, 0.6, and 0.8 sec. Disrupted
at 0.82 sec.
11: O.K. shot. Li pellets at 0.4, and 0.6 sec. Disrupted at
0.625 sec.
12: Good shot. Li pellet fragment at 0.8 sec.
13: O.K. shot. Disrupted at 0.825 sec.
14: Ip reduced to 0.6 MA. Li pellet at 0.6 sec. Disrupted by
0.62 sec.
15: Lowered FSP gain to 2. Good shot. No pellet.
16: Good shot. Li pellet at 0.8 sec. Disrupted at 0.82 sec.
17: Good shot. Li pellets at 0.4 and 0.6 sec. UFO at 0.67 sec.
18: Moved step down in gain of EF4 from 0.49 sec to 1.2 sec.
Raised Ip to 0.95 MA and raised nel04 to 1.3 x 10^20 m^-2.
Good shot. No pellets.
19: Repeat with Li pellets at 0.6 and 0.9 sec. Good shot.
Long P mode with Li/Moly staying high from 0.9 - 1.13 sec.
20: Li pellets at 0.6 and 1.2 sec. Good shot. Nice MHD activity
21: Good shot. Li pellet at 1.0 sec. Nice MHD activity
22: Li pellet at 1.0 sec. Good shot. Nice MHD activity after
2nd pellet.
23: Ip raised to 1.2 MA and nel to 1.4 x 10^20 m^-2.
Li pellet at 0.6 sec. Disrupted at 0.81 sec. Halo current
above 250 kA.
24: Lowered Ip to 0.8 MA and nel04 to 1.0 x 10^20 m^-2. No
pellet. Good shot.
25: Ip set to 1 MA, nel = 1.3 x 10^20 m^-2. Li pellet at 0.8
sec. Good shot. Long P mode with the density hanging up
for 0.15 sec.
26: Disrupted at 0.8 sec. Li pellets at 0.6 and 0.7 sec. Halo
current above 150 kA.
27: Trying again with one pellet at 0.6 sec and one pellet at
1.0 sec. Good shot. Long P modes.
28: Repeat with Li pellets at 0.6 and 0.62 sec. Second pellet
will be small. Good shot.
29: Reloaded shot 19 with Ip=0.95 MA. Li pellet at 0.6 sec.
Good shot.
30: Li pellet at 0.6 sec. Disrupted at 0.68 sec. Halo current
warning with over 150 kA.
31: Li pellets at 0.8 and 0.82 sec. Disrupted at 0.88 sec.
Halo current warning with over 150 kA.
32: Returned to 0.8 MA with nel04 set to 1.0 x 10^20 m^-2.
Li pellet at 0.6 sec. Disrupted at 0.69 sec.
33: Ip raised to 0.85 MA, then ramped down from 0.7 to 0.8 sec
to 0.5 MA. Li pellet at 0.8 sec. Disrupted at 0.805 sec.
34: Ip set to 0.85 MA flattop. Potassium chloride pellet at
0.7 sec. Finger trouble that resulted in zero proportional
gain early in the shot on Ip. Railed the EF2 power supplies
and led to a disruption at 0.72 sec.
35: Copied Ip wire from shot 950518019 and reduced the flattop
current to 0.85 MA. Potassium chloride pellet at 0.7 sec.
led to a disruption at 0.72 sec.
36: Li pellets at 0.6 and 0.8 sec. Disrupted at 0.81 sec.





Session Leader Comments
May 19 1995 09:31:34:890AMDarren GarnierThis is the LPI polarimeter q profile run. First we will optimize
the polarimeter data, then vary the q profile by scanning and
ramping the current. We may also try to get in the KCl doped pellets.

May 18 1995 09:25:09:790AM950518001Darren Garnier OH Test shot.

May 19 1995 09:32:04:030AM950518001Darren GarnierOH Test shot.

May 19 1995 09:37:00:660AM950518002Darren GarnierReload vanilla 820kA shot from yesterday (shot 24). 2 medium
pellets at .6 and .8 sec. Zeeman spectrometer set at 5484.7
(6-181). PM voltage is 550 Volts. PGA gain at 8.

May 19 1995 09:46:02:000AM950518003Darren GarnierLast shot was a Dud. Try again. Plasma, pellets, but no data.
Data acquistion problems.

Physics Operator Comments
May 18 1995 08:58:35:110AM950518001Joseph SnipesShot 1
Power supply test. Resistance of OH2L o.k.

May 18 1995 08:55:58:520AM950518002Joseph SnipesShot 2
Prefill set to 1.7 x 10^-5 Torr. Starting by copying shot 950517024. Power
supply fault after shot 1 test shot was not reset before shot 2. Dud!

May 18 1995 09:22:58:980AM950518003Joseph SnipesShot 3
Good shot. Li pellets at 0.6 and 0.8 sec. Traq 2 magnetics data corrupted.
So, EFIT analyses will not run properly. LPI data acquisition failed,
apparently due to an incorrect software change.

May 18 1995 09:33:51:760AM950518004Joseph SnipesShot 4
Good shot. Very small Li pellets at 0.6 and 0.8 sec.
LPI data acquisition failed again.

May 18 1995 09:54:22:570AM950518005Joseph SnipesShot 5
Good shot. Li pellet at 0.6 sec.

May 18 1995 09:54:58:370AM950518006Joseph SnipesShot 6
Good shot. Li pellet at 0.6 sec.

May 18 1995 10:10:14:340AM950518006Joseph SnipesShot 7
Good shot. No Li pellet.

May 18 1995 10:33:39:850AM950518008Joseph SnipesShot 8
Good shot. Li pellet at 0.6 sec caused TCI to lose fringes.

May 18 1995 11:04:59:820AM950518009Joseph SnipesShot 9
Good shot. Li pellets at 0.4 and 0.8 sec caused TCI to lose fringes at 0.8 sec.
Disrupted at 1.0 sec.

May 18 1995 11:11:15:780AM950518010Joseph SnipesShot 10
Good shot. Li pellets at 0.4, 0.6, and 0.8 sec. Disrupted at 0.82 sec.

May 18 1995 11:13:45:600AM950518011Joseph SnipesShot 11
O.K. shot. Li pellets at 0.4, and 0.6 sec. Disrupted at 0.625 sec.

May 18 1995 11:28:50:110AM950518012Joseph SnipesShot 12
Good shot. Li pellet fragment at 0.8 sec.

May 18 1995 11:46:37:450AM950518013Joseph SnipesShot 13
Lowered gain on Ip from 6 to 4 during the flattop. Li pellet at 0.8 sec.
Disrupted at 0.82 sec.

May 18 1995 12:04:49:470PM950518014Joseph SnipesShot 14
Ip reduced to 0.6 MA. Li pellet at 0.6 sec. Disrupted by 0.62 sec.

May 18 1995 12:10:29:050PM950518015Joseph SnipesShot 15
Lowered FSP gain to 2 throughout the shot. Good shot. No pellet.

May 18 1995 12:28:22:200PM950518016Joseph SnipesShot 16
Good shot. Li pellet at 0.8 sec. Disrupted at 0.82 sec.

May 18 1995 12:46:40:180PM950518017Joseph SnipesShot 18
Good shot. Li pellets at 0.4 and 0.6 sec. Some UFO at 0.67 sec.

May 18 1995 12:53:43:430PM950518018Joseph SnipesShot 18
Moved step down in gain of EF4 from 0.49 sec to 1.2 sec. Raised Ip to 0.95 MA
and raised nel04 to 1.3 x 10^20 m^-2. Good shot. No pellets.

May 18 1995 01:11:45:880PM950518019Joseph SnipesShot 19
Repeat with Li pellets at 0.6 and 0.9 sec. Good shot. Long P mode with Li/
Moly staying high from 0.9 - 1.13 sec.

May 18 1995 01:34:17:910PM950518020Joseph SnipesShot 20

Li pellets at 0.6 and 1.2 sec. Good shot. Nice MHD activity after 2nd pellet.

May 18 1995 01:45:56:460PM950518021Joseph SnipesShot 21
Li pellet at 1.0 sec. Good shot. Nice MHD activity after 2nd pellet.

May 18 1995 01:50:53:050PM950518022Joseph SnipesShot 22
Li pellet at 1.0 sec. Good shot. Nice MHD activity after 2nd pellet.

May 18 1995 02:15:17:140PM950518023Joseph SnipesShot 23
Raised Ip to 1.2 MA and nel04 to 1.4 x 10^20 m^-2. Li pellet at 0.6 sec.
Disrupted at 0.81 sec. Halo current above 250 kA.

May 18 1995 02:28:00:740PM950518024Joseph SnipesShot 24
Lowered Ip to 0.8 MA and nel04 to 1.0 x 10^20 m^-2. No pellet. Good shot.

May 18 1995 02:38:52:400PM950518025Joseph SnipesShot 25
Raised Ip to 1.0 MA and nel04 to 1.3 x 10^20 m^-2. Li pellet at 0.8 sec.
Good shot. Long P mode with the density hanging up for 0.15 sec.

May 18 1995 02:54:52:810PM950518026Joseph SnipesShot 26
Reloaded shot 19 with Ip = 0.95 MA, nel = 1.3 x 10^20 m^-2. Disrupted at
0.8 sec. Li pellets at 0.6 and 0.7 sec. Halo current above 150 kA.

May 18 1995 03:08:44:100PM950518027Joseph SnipesShot 27
Trying again with one pellet at 0.6 sec and one pellet at 1.0 sec. Good shot.
Long P modes.

May 18 1995 03:28:50:140PM950518028Joseph SnipesShot 28
Repeat with Li pellets at 0.6 and 0.62 sec. Second pellet will be small.
Good shot.

May 18 1995 03:30:09:400PM950518029Joseph SnipesShot 29
Reloaded shot 19 with Ip = 0.95 MA. Li pellet at 0.6 sec. Good shot.

May 18 1995 03:54:58:530PM950518030Joseph SnipesShot 30
Li pellet at 0.6 sec. Disrupted at 0.68 sec. Halo current warning with over
150 kA.

May 18 1995 03:58:40:760PM950518031Joseph SnipesShot 31
Li pellets at 0.8 and 0.82 sec. Disrupted at 0.88 sec. Halo current warning
with over 150 kA.

May 18 1995 04:19:38:550PM950518032Joseph SnipesShot 32
Returned to 0.8 MA with nel04 set to 1.0 x 10^20 m^-2. Li pellet at 0.6 sec.
Disrupted at 0.69 sec.

May 18 1995 04:28:58:130PM950518033Joseph SnipesShot 33
Ip raised to 0.85 MA, then ramped down from 0.7 to 0.8 sec to 0.5 MA. Li
pellet at 0.8 sec. Disrupted at 0.805 sec.

May 18 1995 04:50:03:040PM950518034Joseph SnipesShot 34
Ip set to 0.85 MA flattop. Potassium chloride pellet at 0.7 sec. Finger
trouble that resulted in zero proportional gain early in the shot on Ip.
Railed the EF2 power supplies and led to a disruption at 0.72 sec.

May 18 1995 04:58:25:330PM950518035Joseph SnipesShot 34
Copied Ip wire from shot 950518019 and reduced the flattop current to 0.85 MA.
Potassium chloride pellet at 0.7 sec. led to a disruption at 0.72 sec.

May 18 1995 04:59:48:400PM950518035Joseph SnipesShot 35
Copied Ip wire from shot 950518019 and reduced the flattop current to 0.85 MA.
Potassium chloride pellet at 0.7 sec. led to a disruption at 0.72 sec.

May 18 1995 05:38:21:000PM950518036Joseph SnipesShot 36
Repeat with Li pellets at 0.6 and 0.8 sec. Disrupted at 0.81 sec.

Engineering Operator Comments
ShotTimeTypeStatusComment
108:32:06:660AMTestOkcoax test
208:40:50:070AMPlasmaBadswitches didn't fire
308:56:55:420AMPlasmaOk
409:25:36:160AMPlasmaOk
509:39:15:890AMPlasmaOk
609:49:17:810AMPlasmaOk
710:05:37:880AMPlasmaOk
810:19:45:050AMPlasmaOk
910:39:32:660AMPlasmaOk
1010:55:18:320AMPlasmaOk
1111:07:56:630AMPlasmaOk
1211:22:06:920AMPlasmaOk
1311:36:13:550AMPlasmaOk
1411:50:43:850AMPlasmaOk
1512:06:15:790PMPlasmaOk
1612:19:06:400PMPlasmaOk
1712:32:19:850PMPlasmaOk
1812:49:13:390PMPlasmaOkNo Faults.
1901:02:05:690PMPlasmaOkNO Faults.
2001:15:08:340PMPlasmaOkNo Faults.
2101:29:07:820PMPlasmaOkNo Faults.
2201:41:59:620PMPlasmaOkNO Faults.
2301:55:51:270PMPlasmaOk
2402:17:24:160PMPlasmaOk
2502:30:00:700PMPlasmaOk
2602:44:22:730PMPlasmaOk
2702:57:27:970PMPlasmaOk
2803:11:30:300PMPlasmaOk
2903:24:30:300PMPlasmaOk
3003:36:53:420PMPlasmaOk
3103:51:01:180PMPlasmaOk
3204:05:32:500PMPlasmaOk
3304:19:40:380PMPlasmaOk
3404:33:47:950PMPlasmaOk
3504:50:13:710PMPlasmaOk
3605:02:43:320PMPlasmaOk