Alcator C-Mod Weekly Highlights
		          August 3, 1998


Engineering:

	Eighty-nine new sheets of feltmetal arrived last week.  They have
already been hydrogen furnace cleaned at Wall Colmonoy in Ohio, and returned
to MIT.  As mentioned in the last report, an unapproved change in the plating
procedure used by our vendor resulted in an unacceptable coating on 18 sheets
of feltmetal we already had in house.  This problem has been resolved,
but it has already delayed somewhat the production soldering.  A C-Mod
engineer will now be onsite with the vendor to check each new feltmetal
sheet as it is plated.  This time has been used to make improvements to
the fixturing, so we expect the production soldering to go quickly once the
feltmetal is available.
	We continue to run wear tests on feltmetal samples.  We have now
qualified the brush plating process to be used on the bare copper fingers.
We have also found that application of electrodag, a graphite suspension in
alcohol, much improves the performance of the feltmetal.  This result is
consistent with similar tests performed on the feltmetal used for the MAST
tokamak at Culham.
	Now that new components have been procured, repairs to the FMIT#4
input cavity are underway.  We have rebuilt the load isolation capacitor,
the input cavity has been reassembled, and the transmitter awaits tube
and output cavity installation.  Initial tests will begin after the tube has
been conditioned.
	We continued development of the DNB for C-Mod.  Progress continued on
the fiber optic systems including fiber mounting, amplifier boards, and analog
patch panel to the fast fiber optic chassis.  Work completed on the
accelerator supply included finishing the HV divider isolation amplifier
board and chassis,  HV Power Supply Panel 1 layout, and gates
Inhibited/Reset Interface board.  The HV Supply control power status board
was designed.  Machining continued on the F-Port flange which will be used
for the DNB.
	The final design review for the new K port horizontal flange was held
on July 27th. The review was passed successfully and final drawings are being
produced for machining purposes.  The new design was necessary as many
diagnostics had to be relocated following the installation of the new 4 strap
antenna and the DNB with its associated diagnostics. Included in the new
design are the impurity injector, core bolometric system
(bolometers, AXUV diodes and 2pi bolometers), Z-meter array (profile
information), Halpha reticon array, Chromex spectrometric view, divertor
spectrometer (Johns Hopkins collaboration), Low energy Neutral Particle
Analyzer (TOF), and tangentially viewing neutron collimator and spectrometer.
Additional modifications will be made to the RF protection limiters in order
to allow for the changes brought about by all the new installations.


Travel and Visits:

	Bob Ellis from PPPL (lead engineer for the PPPL antenna) visited
last week to make some internal machine measurements and survey J-port.
	Dave Johnson and Ben LeBlanc visited from PPPL to continue
investigating  the cause of low signal levels obtained on the X-point Thomson
scattering system during the last campaign. Several factors were identified,
including lower than nominal output power from the laser and a misalignment of
the fiber optic assembly with respect to the viewing optics. In addition, the
optical efficiency of the collection optics was found to be significantly
lower than the design specification. Possible remedies are being considered.