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sci.physics.plasma
From IRBY@CMOD2.PFC.MIT.EDU Tue Apr 16 16:59:31
1996
From: IRBY@CMOD2.PFC.MIT.EDU
Organization: MIT
Subject: Alcator C-MOD Weekly Highlights
Alcator C-MOD Weekly
Highlights
April
16, 1996
Invessel cleanup
is now complete. The wipes from the
first
wall are now being processed in an ultrasonic bath and the
residue
will be analyzed for the ITER dust initiative. Work has begun on
installation of a new
camera fixture which mounts on the inner wall
of the vessel. This fixture will allow 35mm photographs to
be made
of the entire outer wall and upper and lower divertor in a precise
and
reproducible manner. The
fixture consists of a circular track surrounding
the inner wall on which
mounts for supporting the cameras and light
sources travel.
Work continues on our new RF
transmitters. All conduit
runs for
utility power, control, and diagnostics are now complete. The
480 VAC power to the cooling system
pumps is now installed. All PLC
interface
cables linking the driver to the control cabinet are fabricated.
The west side of the diagnostics stand is
complete. We are now
preparing to
move some of the control and diagnostic racks that are
presently very
close to the machine out to the extension.
This change will
provide more room for hardware that must be
located near the machine, such
as feeds for the new RF antenna. The east side of the stand extension
will
be finished as soon as relocation of the diborane vent line is
complete.
The alternator has
been officially certified for three more years
of operation by GE, and
reassembly has already begun.
Modifications to
the flywheel bearings are well underway. These changes will improve oil
flow
around the bearings and help damp oscillations.
New analysis of C-MOD disruption data indicates a
possible
correlation between halo current magnitude and the location of
the plasma
strike point following a VDE, for a given plasma current.
Plasmas which
end up limiting primarily on the top of the outboard
divertor module exhibit
higher ratios of I_Halo/I_p, compared to cases in
which the plasma contacts
both inboard and outboard divertors. Including a
measure of the
relative plasma proximity to the inner and outer structures
as a scaling
parameter may reduce the scatter in our data, and improve our
ability to
predict halo currents
Rostom Dagazian,
our new contract monitor, visited last week to
discuss various aspects of
the C-MOD program. Rajesh Maingi from
DIII-D
also visited last week and gave a seminar on recent DIII-D divertor
results. Martin Greenwald was at the University of
Wisconsin last week
and gave two seminars, one on C-MOD transport and
another on density limits.
Papers recently accepted for
publication:
X-ray Observations of 2l - nl' Transitions from Zr, Nb,
Mo and Pd in Near
Neonlike Charge States, by J. E. Rice, K. B. Fournier,
J. L. Terry,
M. A. Graf, M. Finkenthal, E. S. Marmar and W. H.
Goldstein
to appear in Phys Rev A
X-ray and VUV Observations of
Mo23+ - Mo33+ Brightness Profiles from
Alcator C-Mod Plasmas, by J. E.
Rice, J. L. Terry, K. B. Fournier,
M. A. Graf, M. Finkenthal, M. J. May,
E. S. Marmar, W. H. Goldstein
and A. E. Hubbard
to appear in J. Phys.
B