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


Alcator C-MOD Weekly Highlights
September 8, 1994

The repair/maintenance period for Alcator C-MOD is continuing. The reassembly
phase has now begun. The central core, consisting of the central column of the
TF magnet and the OH stack, has now been re-installed.

The components for the OH2L coaxial buss are now in-house. A model coax has
been bent to shape in order to test the bending fixture and validate the
procedure. Preparations for assembly of the final coax are proceeding.

A new ten-segment toroidal rogowski coil has been installed in the lower
section of of the vacuum vessel. This diagnostic will provide additional
information on the toroidal distribution of halo currents during disruptions.

The coil model used by the EFIT equilibrium analysis code has been modified to
use as-built, rather than as-designed, dimensions for the OH stack. Modeling of
the other PF coils had already been based on as-built dimensions.
Recalculation of old shots using the improved coil model gives reduced
chi-squared values and leads to small but significant changes in the
equilibria. In particular, the location of the inner strike point on divertor
discharges is affected, in a way that is more consistent with probe and other
measurements. In addition, the EFIT values for the stored energy using the
revised model are in better agreement with the kinetic calculation based on
integration of profile data.

A copy of the ITER H-mode database has been loaded into our RdB format, for
easier access by C-MOD personnel. This enables us to use our standard
database tools to examine the ITER compilation, and facilitates comparison
with locally available data.

Dr. Garry McCracken visited PPPL this week for discussions related to the Edge
Thomson Scattering Collaboration. He also had consultations with Drs. Stotler
and Petravic on progress in DEGAS and PLANET modeling of C-MOD edge data.

Horst Kroegler from ENEA, Frascati began a 2 month visit this week. He will
collaborate on radiated power measurements.