Newsgroups: sci.physics.plasma
From IRBY@CMOD2.PFC.MIT.EDU Wed Apr 3 11:00:13 1996
From: IRBY@CMOD2.PFC.MIT.EDU
Organization: MIT
Subject: Alcator C-MOD Weekly Highlights

Alcator C-MOD Weekly Highlights
April 3, 1996

In-vessel work began this week. A video survey of the
internals was made and an inspection of the first wall
hardware carried out. The inspection of the first wall showed no broken
or loose tiles, or bent support plates. Therefore changes made to the
support structure during the last up to air were adequate for
our current operating parameters. Before coming up to air,
glow discharge cleaning was performed to further reduce the level
of boron hydrides in the machine. This process required the
construction of a glow discharge electrode and switchable ballast
resistor bank. A discharge was easily maintained down to pressures
of approximately 2mT where the electrode potentials could be kept
in the 300 to 400 volt range. These potentials are believed to be
high enough to break down the heavier borane compounds.
The alternator inspection continues. The flywheel lifting
frame has been installed and the lower flywheel bearing removed for
inspection. Some repair work will be required on the lower bearings.
Ultrasonic tests of the bore and UT have continued and are nearing
completion.
The HVDC conduit and cables for ICRF transmitter #4
have been installed. The 480 VAC control power has been run to
the FMIT driver distribution system for transmitters #3 and #4
as well as to the water cooling systems. The 4-port switch is in
house and being prepared for installation. This switch allows the
transmitters to be switched between a dummy load and the antennas.
Support legs and trusses have been installed for the diagnostic
stand extension. Planning continues for moving racks and hardware
away from near the machine and onto the new stand.
Vacuum system work, PLC programming, and instrumentation
installation for the cryopump prototype continues. Cooldown cycle
tests and pumping speed measurements will be made shortly.
Jon McChesney visited from General Atomics this week and
gave a talk. Ian Hutchinson is in Washington for the IAEA paper
review.