Newsgroups: sci.physics.plasma
From WOLFE@CMOD2.PFC.MIT.EDU Tue Jun 27 16:07:36 1995
From: WOLFE@CMOD2.PFC.MIT.EDU
Organization: MIT
Subject: Alcator C-MOD Weekly Highlights

Alcator C-MOD Weekly Highlights
June 27, 1995

The scheduled maintenance and upgrade interval is continuing. Most activities
were concentrated on machine inspection and preparation for new installations.

The igloo cover and top two tiers of igloo blocks were removed. The upper half
of the cryostat was then removed, providing access for inspection of the
superstructure, cooling lines and buswork, as well as facilitating removal of
horizontal port extensions.

The E-port ICRF antenna was removed for installation of new antenna protection
tiles. The bellows on the current feeds will also be replaced with an
improved design. A small leak in the E-port horizontal port secondary seal
will also be repaired.

A detailed survey of the first wall was carried out, with all loose and
damaged tiles mapped out. The gusset protection tiles will be replaced with
new, stronger material (already on hand), and the corner tiles have been
redesigned for better heat load distribution. Inspection and removal of inner
divertor modules for refurbishing continued. Measurements of the outer
divertor modules indicated essentially no displacement or distortion since the
previous inspection last fall.

A full set of current sensing rogowskis to be installed on the outer divertor
modules has been completed. These will replace the shunts presently used to
measure halo currents flowing through the divertor modules.

Marker tiles installed at the beginning of the last campaign were retrieved
and sent to Sandia for analysis. These tiles incorporated a thin layer of
tungsten covered with an evaporated layer of 100nm of molybdenum, and are used
for analysis of erosion and deposition during machine operation. Marker tiles
were retrieved from the inner wall and divertor structures.