Newsgroups: sci.physics.plasma
From WOLFE@CMOD2.PFC.MIT.EDU Tue Jun 20 10:53:06 1995
From: WOLFE@CMOD2.PFC.MIT.EDU
Organization: MIT
Subject: Alcator C-MOD Weekly Highlights

Alcator C-MOD Weekly Highlights
June 19, 1995

Alcator C-MOD is presently in a scheduled maintenance and upgrade period. The
operating campaign just completed lasted from November 17,1994 through
June 9,1995, and included 27 run weeks, during which over 2300 successful
plasma shots were produced. The present maintenance period will continue
through the summer. Major planned activities include installation of a
divertor Thomson scattering system, in collaboration with PPPL and PSI,
and installation of a prototype divertor cryopump. Additional maintenance on
internal and external hardware is also planned.

Following completion of operation, the machine was allowed to warm up to room
temperature.

New density feedback electronics were installed and tested.

A final calibration of the Thomson scattering system was performed, including
Rayleigh scattering with the vessel back-filled in argon, and Raman scattering
with hydrogen back-fill.

A full leak check of all horizontal and vertical port Helicoflex (TM) seals
was performed prior to breaking vacuum on Friday. The vessel was then brought
up to air, and the large ports at G and C-ports removed to allow manned
access.

An inspection and survey was performed for the in-vessel hardware. In general,
the internal components were found to be in good condition. The outboard
divertor modules were in excellent shape, as were the outboard limiters. The
ICRF antennas were also in very good condition.In addition to the two gusset
protection tiles already known to have broken, four molybdenum tiles from
inner divertor modules and one from an outer divertor module were found to
have split and broken loose. There are a total of over 7000 molybdenum tiles
in the divertor and first wall, and the loss of this small number had no
detectable effect on operation. There were also some small misalignments of
the lower inner divertor modules, presumably from disruption forces. These
modules are being removed for further inspection and refurbishing.

A list of alternator maintenance tasks to be carried out over the summer
has also been developed, and these activities have begun.