Alcator C-Mod Run 950407 Information

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Miniproposals
Miniproposal:
Date Filed:
Title:
First Author:
Session Leader:Martin Greenwald (shots 1-39)

Operators
Session leader(s):Martin Greenwald
Physics operator(s):Earl Marmar
Engineering operator(s): Unknown

Engineering Operator Run Comment
Boivin/Marmer

Session Leader Plans

Physics Operators Plans

Session Leader Summaries
Entered: Jul 7 2004 03:49:13:303PM
Author: To Be Determined
Run Plan
--------

This run was part of MP 85 - Dimensionless scaling experiments. A
continuation of runs on 950302 and 950303. The field was reserved to
suppress H-modes at the higher powers.

The basic outline of the run are power scans at two fixed densities - nebar
= 1.5 and ~3.0 e20 (nel ~ .9 and 1.8).

The other conditions are R= .67, a = .22, kappa = 1.7, Ip = 1.02 with
a SNB equilibrium. Inner and outer gaps should be about 1 cm.

We start with shot 950406036 (the last shot from yesterday),
We tweak the density and equilibrium as needed from there, starting with
the lower density.

We then scan the RF power from its maximum value.

When we reach the maximum power at ne = 1.5, we will raise the density to
around 3.0 and repeat the power scan.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Results:

A mixed bag. Of 38 attempts, their were only 20 plasmas, 18 that lasted
long enough for the RF to fire. (Most of the "good" shots disrupted at the
end of flat-top or the beginning of ramp-down. The RF systems seemed to be
working well - Prf up to 3.2 MW, Ptot = 4.7 MW on shot 16 Ip, kappa, a and
R were near their specified values for all (good) shots. Many disrupted at
the end of flattop or early during rampdown. We probably have adequate data
at the lower density but nothing really at the higher density.

Scorecard:
"good" shots 18 (11 with late full-current disruptions)
early disruptions - 2
fizzles - 18


Shots suitable for further analysis are:

SHOT: 950407001
nebar = 2
ohmic

SHOT: 950407004
nebar = 1.4
Prf = .65 MW

SHOT: 950407005
nebar = 1.8
Prf = .95 MW

SHOT: 950407006
nebar = 1.8
Prf = 1.0 MW (estimated)

SHOT: 950407007
nebar = 1.9
Prf = 2.0 MW

SHOT: 950407008
nebar = 1.9
Prf = 2.4 MW; (Ptot = 3.6MW)

SHOT: 950407009
nebar = 2
Prf = 2.7 MW; but trips early to 1.3 MW (full power for a bit less than .1 sec)

SHOT: 950407010
nebar = 1.9
Prf = 1.1 MW; trips on second transmitter

SHOT: 950407011
Disrupted early

SHOT: 950407013
nebar = 1.9
Prf = 2.5 MW

SHOT: 950407014
nebar = 1.8
Prf = 2.7 MW (Ptot = 3.9 MW)

SHOT: 950407016
nebar = 2.2
Prf = 3.2 MW; Ptot > 4.5 MW; Wmhhd > .11 MJ

SHOT: 950407019
nebar = 1.5
RF power ~1.2 MW (trips)

SHOT: 950407021
nebar = 1.6
Prf = 1.5 MW but for only 20 msec

SHOT: 950407023
disrupts at end of flattop
nebar = 1.6
Prf = 1.5 MW

SHOT: 950407025
nebar = 1.7
Ohmic only

SHOT: 950407027
Attempt to increase density
nebar = 2.6
Prf = 1.3 MW for 80 msec

SHOT: 950407033
nebar = 2.4
Prf = 1.4 MW with many trips at higher powers

SHOT: 950407038
nebar = 2.6
Only short bursts on RF

Physics Operator Summaries

Session Leader Comments
Apr 7 1995 08:37:25:920AMMartin GreenwaldRun Plan
--------

The basic outline of the run are power scans at two fixed densities -
nebar = 1.5 and ~3.0 e20 (nel ~ .9 and 1.8).

The other conditions are R= .67, a = .22, kappa = 1.7, Ip = 1.02 with
a SNB equilibrium. Inner and outer gaps should be about 1 cm.

We start with shot 950406036 (the last shot from yesterday),
We tweak the density and equilibrium as needed from there, starting with
the lower density.

We then scan the RF power from its maximum value.

When we reach the maximum power at ne = 1.5, we will raise the density to
around 3.0 and repeat the power scan.

Apr 7 1995 08:36:41:700AM950407001Martin Greenwald1 MA disrupts at 1.sec
nl04 = 1.3
no RF yet

Apr 7 1995 08:44:21:940AM950407002Martin Greenwaldfizzle

Apr 7 1995 09:18:31:980AM950407003Martin Greenwaldfizzle

Apr 7 1995 09:38:24:240AM950407004Martin GreenwaldIp reached 1 MA
disrupted on rampdown
nl04 = .9
Prf = .65 MW

Apr 7 1995 09:49:26:890AM950407005Martin GreenwaldGood Shot
Ip = 1.05 MA
nl06 = 1.0, ne0yag = 1.4
Prf = .95 MW

Apr 7 1995 10:06:33:270AM950407006Martin GreenwaldGood Shot
Ip = 1.05 MA
nl06 = 1.0, ne0yag = 1.4
Prf = 1.0 MW (estimated)

Apr 7 1995 10:18:18:410AM950407007Martin GreenwaldGood Shot
Ip = 1.05 MA
nl06 = 1.0, ne0yag = 1.4
Prf = 2.0 MW - Te0 almost 4keV

Apr 7 1995 10:38:37:890AM950407008Martin GreenwaldGood Shot
Ip = 1.05 MA
nl06 = 1.0, ne0yag = 1.4
Prf = 2.4 MW; (Ptot = 3.6MW)

Apr 7 1995 10:47:57:280AM950407009Martin GreenwaldGood Shot
Ip = 1.05 MA
nl06 = 1.0
Prf = 2.7 MW; but trips early (full power for a bit less than .1 sec)

Apr 7 1995 11:05:46:350AM950407010Martin GreenwaldDisrupted
Ip = 1.05 MA
nl06 = 1.0
Prf = 1. MW; trips on second transmitter

Apr 7 1995 11:22:37:420AM950407011Martin GreenwaldDisrupted
Ip = 1.05 MA
nl06 = 1.0

Apr 7 1995 11:28:35:300AM950407012Martin Greenwaldfizzle

Apr 7 1995 11:38:56:450AM950407013Martin GreenwaldGood Shot
Started with some runaways
Ip = 1 MA
nl = 1.
Prf = 2.5 MW

Apr 7 1995 11:54:45:810AM950407014Martin GreenwaldDisrupts on rampdown
Started with some runaways
Ip = 1 MA
nl = 1.
Prf = 2.7 MW

Apr 7 1995 12:05:30:570PM950407015Martin Greenwaldfizzle

Apr 7 1995 12:15:38:890PM950407016Martin GreenwaldDisrupts at the end of flat-top
Prf = 3.2 MW

Apr 7 1995 12:43:48:380PM950407017Martin Greenwaldfizzle

Apr 7 1995 01:14:26:120PM950407019Martin GreenwaldDisrupts at end of flattop
RF power ~1.2 MW (trips)
Ip = 1 MA

Apr 7 1995 01:26:45:290PM950407020Martin Greenwaldfizzle

Apr 7 1995 01:40:27:140PM950407021Martin GreenwaldDisrupts at end of flattop
Ip = 1 MA
Prf = 1.5 MW but for only 20 msec

Apr 7 1995 01:58:12:620PM950407022Martin Greenwaldfizzle

Apr 7 1995 02:06:53:380PM950407022Martin Greenwalddisrupts at end of flattop
Ip = 1 MA
Prf = 1.4 MW

Apr 7 1995 02:07:04:700PM950407023Martin Greenwalddisrupts at end of flattop
Ip = 1 MA
Prf = 1.4 MW

Apr 7 1995 02:17:22:690PM950407024Martin Greenwaldfizzes

Apr 7 1995 02:28:29:320PM950407025Martin Greenwalddisrupted on rampdown
Ip = 1 MA
Ohmic only

Apr 7 1995 02:44:44:550PM950407026Martin Greenwaldfizz

Apr 7 1995 03:03:06:730PM950407027Martin GreenwaldAttempt to increase density
disrupts during flattop
Ip = 1. MA
Prf = 1.3 MW for 80 msec

Apr 7 1995 03:13:04:180PM950407028Martin GreenwaldFizz

Apr 7 1995 03:21:13:440PM950407029Martin GreenwaldFizz

Apr 7 1995 03:29:31:720PM950407030Martin GreenwaldFizz

Apr 7 1995 03:43:47:600PM950407031Martin GreenwaldFizz

Apr 7 1995 04:07:32:710PM950407032Martin GreenwaldBreakdown but early termination

Apr 7 1995 04:13:35:060PM950407033Martin GreenwaldGood shot
Ip = 1. MA
Prf = 1.4 MW with some higher peaks
nel = 1.4

Apr 7 1995 04:19:50:810PM950407034Martin Greenwaldfizzle

Apr 7 1995 04:36:46:170PM950407035Martin Greenwaldfizzle

Apr 7 1995 04:36:53:810PM950407036Martin Greenwaldfizzle

Apr 7 1995 04:44:36:290PM950407037Martin Greenwaldfizzle

Apr 7 1995 04:57:12:760PM950407038Martin GreenwaldDisrupts at rampdown
Ip = 1.0 MA
Only short bursts on RF

Apr 7 1995 05:05:54:250PM950407039Martin Greenwaldfizzle

Physics Operator Comments
Apr 7 1995 08:38:00:490AM950407001Earl MarmarStart with last shot from yesterday, 950406036, 1MA, but lower nl_04
to 1.2e20. Fill and puff from A-side, D2. Fill 2.0e-5.

Plasma; disrupt at 1 s, EF2U hit current limit

Apr 7 1995 08:42:38:060AM950407002Earl MarmarLower nl_04 to 0.9e20
increase EF4/EF2 gain to 1 from 0.5
fill 2.2e-5

fizzle

Apr 7 1995 09:19:12:360AM950407003Earl Marmarfill 2.0 e-5

decrease clearin ramp by 3 mm at 1 s.

fizzle

Apr 7 1995 09:40:32:560AM950407004Earl Marmarfill 2.1 e-5

add 5e-4 Br offset

plasma, disrupt at .92 MA

Apr 7 1995 09:53:43:620AM950407005Earl Marmarfill 2.1 e-5

raise nl_04 to 1.1e20

remove clearin ramp (flat during flat-top)

plasma, disrupt at .92 MA

Apr 7 1995 09:53:58:400AM950407005Earl Marmarfill 2.1 e-5

raise nl_04 to 1.1e20

remove clearin ramp (flat during flat-top)

plasma, ramped down all the way

Apr 7 1995 10:01:53:510AM950407006Earl Marmarfill 2.1 e-5

delay current flat-top by 50 msec

add argon

tweak zxu (slightly lower)

good plasma

Apr 7 1995 10:38:28:190AM950407007Earl Marmarfill 2.1 e-5

minor clearin tweak

good plasma, 2 MW RF, 4keV Te at tops of sawteeth

Apr 7 1995 10:38:50:420AM950407008Earl Marmarfill 2.1 e-5
good plasma, 2 MW RF

Apr 7 1995 10:43:03:160AM950407008Earl Marmarwas actually 2.4 MW

Apr 7 1995 10:54:57:140AM950407009Earl Marmarfill 2.1e-5

jog rcur (out 2 mm between .7 and .9 s)

good plasma, 2.7 MW for some time

Apr 7 1995 11:13:18:070AM950407010Earl Marmarfill 2.1e-5

increase clearin by 5 mm, rcur by 2 mm (try to increase kappa slightly),
make the rcur jog at .7 sec into a ramp

disrupt at 0.9 s
ef2's were oscillating slowly, lost it vertically
got the kappa we wanted (1.7)

Apr 7 1995 11:21:02:080AM950407011Earl Marmarfill 2.1e-5

change ef2/ef4 to ask for 3kA on ef2's
disrupted at .9, ef2's hit 4000 A

Apr 7 1995 11:40:40:370AM950407012Earl Marmarfill 2.1e-5

re-load shot 9

fizzle

Apr 7 1995 11:55:42:590AM950407012Earl Marmarfill 2.2e-5

plasma, some hards early

Apr 7 1995 11:55:56:840AM950407013Earl Marmarfill 2.3e-5

plasma

Apr 7 1995 11:58:41:200AM950407014Earl Marmarfill 2.3e-5

plasma, disrupt at .9 s
halo current >200 ka

Apr 7 1995 12:05:35:120PM950407015Earl Marmarfill 2.1e-5

fizzle

Apr 7 1995 12:26:47:470PM950407016Earl Marmarfill 2.1e-5

move rxu down by 1 cm

plasma, disrupt at end of flat-top, 3.2 MW RF

Apr 7 1995 12:53:25:210PM950407017Earl Marmarfill 2.1e-5

lower ef2/ef4 gain to .3 at .72 s, Br offset to 0 from +5e-4

fizzle

Apr 7 1995 01:02:32:160PM950407018Earl Marmarfill 2.2e-5

add 50 to IC_oh1 in segment 1
add 5e-4 offset to Br
draw RXU up by 1 cm

fizzle

Apr 7 1995 01:23:16:450PM950407019Earl Marmarfill 2.2e-5

50 more amps on OH1, 5e-4 more offset on Br

Apr 7 1995 01:24:38:920PM950407019Earl Marmarplasma, disrupt at end of flattop

Apr 7 1995 01:33:20:350PM950407020Earl Marmarfill 2.2 e-5

BR_0 offset to 0

fizzle

Apr 7 1995 01:50:10:310PM950407021Earl Marmarfill 2.2 e-5

BR_0 offset to +1e-3, 20 amp decrease in ef4

lose FSP control, increase zxl propgain after .5 sec

plasma, disrupt at 1.05, rf tripped

Apr 7 1995 01:55:56:420PM950407022Earl Marmarfill 2.2 e-5

BR_0 offset to 1.5e-3, tweak RXU, lower zcur by 3 mm, ZXL by 3 mm

fizzle

Apr 7 1995 02:15:00:850PM950407023Earl Marmarfill 2.2 e-5

BR_0 offset to 1.0e-3

plasma, 1.5 MW rf, disrupt at 1.05 s

Apr 7 1995 02:19:54:010PM950407024Earl Marmarfill 2.2 e-5

add some RXL propgain after 1 second, 0 strkpsi gain after 1 s

fizzle

Apr 7 1995 02:37:07:010PM950407025Earl Marmarfill 2.2 e-5

no changes
no rf (on purpose), disrupt at end of flat-top

Apr 7 1995 02:45:58:680PM950407026Earl Marmarfill 2.2 e-5

decrease late I_ef4 propgain after 1 s, increase gaps by 5 mm

fizzle

Apr 7 1995 03:07:50:340PM950407027Earl Marmarfill 2.2 e-5

reload segment 1 from 950406036
plasma, disrupt at .9 s

Apr 7 1995 03:13:06:820PM950407028Earl Marmarfill 2.2 e-5

reload segment 2 from 950407009
increase nl_04 to 1.7e20

fizzle

Apr 7 1995 03:21:23:850PM950407029Earl Marmarfill 2.2 e-5

no changes

fizzle

Apr 7 1995 03:40:00:650PM950407030Earl Marmarfill 2.2 e-5

B_R offset +1e-3

fizzle

Apr 7 1995 03:43:58:610PM950407031Earl Marmarfill 2.2 e-5

lower ef1u&l by 200 amp at t=0

fizzle

Apr 7 1995 04:00:41:690PM950407032Earl Marmarfill 2.2 e-5

add 30 amps to ef4

plasma, disrupt just after crossover. looks like something fell
into the plasma (Mo monitor saturates).

Apr 7 1995 04:16:37:220PM950407033Earl Marmarfill 2.2 e-5

repeat

plasma, made it through most of rampdown

Apr 7 1995 04:20:21:320PM950407034Earl Marmarfill 2.4 e-5

increase nl_04 to 1.9e20, tweak rxl (out) and zxl (down)

fizzle

Apr 7 1995 04:28:00:700PM950407035Earl Marmarfill 2.2 e-5

add 20 amps to ef4 at t=0

fizzle

Apr 7 1995 04:39:42:760PM950407036Earl Marmarfill 2.2 e-5

subtract 25 amp from ef4

bouncer fizzle

Apr 7 1995 04:48:42:040PM950407037Earl Marmarfill 2.2 e-5

fizzle bouncer,

Apr 7 1995 05:02:46:830PM950407038Earl Marmarfill 2.4 e-5

10 amps less in ef4's

plasma, disrupt at .95 s

Apr 7 1995 05:08:14:540PM950407039Earl Marmarfill 2.4 e-5

repeat try

fizzle

Engineering Operator Comments
ShotTimeTypeStatusComment
108:24:51:740AMPlasmaOkno faults
208:39:50:270AMPlasmaOkno faults
309:16:07:730AMPlasmaOkno faults
409:25:48:350AMPlasmaOkno faults
509:40:26:500AMPlasmaOkno faults
609:56:51:940AMPlasmaOkno faults
710:08:52:810AMPlasmaOkno faults
810:26:00:290AMPlasmaOkno faults
910:43:43:410AMPlasmaOkno faults
1010:58:57:820AMPlasmaOkNo Faults.
1111:14:38:140AMPlasmaOkno faults
1211:26:53:930AMPlasmaOkno faults
1311:34:37:060AMPlasmaOkno faults
1411:50:14:640AMPlasmaOkno faults
1512:03:55:040PMPlasmaOkno faults
1612:11:54:040PMPlasmaOkno faults
1712:42:20:310PMPlasmaOkno faults
1812:56:41:200PMPlasmaOkNo faults.
1901:08:32:280PMPlasmaOkNo Faults.
2001:25:08:810PMPlasmaOkNo faults.
2101:35:14:100PMPlasmaOkNo Faults.
2201:51:46:380PMPlasmaOkNo Faults.
2302:01:44:000PMPlasmaOkComm. Fault OH1 & OH2L
2402:15:56:810PMPlasmaOk
2502:23:55:460PMPlasmaOkComm. Fault OH1, OH2L,and EF1U.
2602:41:07:300PMPlasmaOkNo faults.
2702:50:08:500PMPlasmaOkNo Faults.
2803:11:25:880PMPlasmaOkNo Faults.
2903:19:37:610PMPlasmaOkNo faults.
3003:28:03:590PMPlasmaOkNo faults.
3103:42:09:040PMPlasmaOkNo faults.
3203:51:06:900PMPlasmaOkOH1 IOC fault TYpe 1
3304:02:54:140PMPlasmaOkNo Faults.
3404:18:15:930PMPlasmaOkno faults
3504:26:19:410PMPlasmaOkno faults
3604:34:55:080PMPlasmaOkno faults
3704:43:14:520PMPlasmaOkno faults
3804:52:11:510PMPlasmaOkno faults
3905:04:13:180PMPlasmaOkno faults