Newsgroups: sci.physics.plasma
From: WOLFE@CMOD2.PFC.MIT.EDU
Subject: Alcator C-MOD Weekly Highlights

Alcator C-MOD Weekly Highlights
August 31, 1994

The repair/maintenance period for Alcator C-Mod is continuing. Most of the
activity this week has been concentrated on production of the new OH coax
busses.

The outer coax tubes have been received from the vendor and mate extremely
well with the coax flanges. The bending fixture has been modified to
accommodate the new design; a model coax is ready for test bending. All of
the silver-plated felt-metal contact pad material is now in-house. The EDM
vendor has completed the second inner coax assembly, and this delivery of
this piece is expected today.

The OH core is being cleaned by flushing the LN2 jacket region with Freon.
The final machining and finishing of the OH2L terminal block has been
completed, and the coils hi-potted (rung) to 5kV. The only remaining
procedure prior to re-installation of the core into the machine is
machining of a relief into a G-10 block at the top of the OH1 coil to
accommodate a position sensor, which is part of the additional
instrumentation being installed as recommended by our engineering review.

DEGAS modeling of the C-Mod plasma is continuing in collaboration with
Stotler at PPPL. EFIT equilibria and plasma temperature and density
profiles for specific 1994 discharges have been used to produce a DEGAS
grid. Halpha emission profiles have been calculated and compared with
experimental data for both inner wall and divertor regions. Assuming
constant temperature and density along a field line satisfactory agreement
is obtained from the inner wall profile, but the divertor data is still
unsatisfactory both in shape and absolute magnitude. The problem is relatedto obtaining good interpolation of density and temperature profiles along
field lines between the measured upstream and target values. An improved
algorithm of the observed gradients of temperature and density along a field line is being developed.