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.