Alcator C-Mod Weekly Highlights
		          August 10, 1998



Engineering:

	We continue wear tests on the feltmetal.  Low current lifetime
tests have reached 100,000 cycles with still very useable feltmetal
remaining.  High current tests at up to 6000 A/cm^2 have reached
over 20,000 cycles with little wear.  This current density is more
than twice the average current density expected during 8 T operation,
but similar to the peak current density during ramp up and ramp
down of the TF field.  Tests up to 9000 A/cm^2 are planned.  High current
tests must be run at low pulse rates to keep from over heating the feltmetal
and are not generally run to an extremely large number of cycles as are the
low current tests.  However,  20,000 cycles at 6000 A/cm^2 is equivalent
to 8 to 9 years of high field operation.
	Silver plating of the new TF feltmetal has produced enough material
to laser cut into pads and compress and bend into the proper shape for
soldering.  We are evaluating the new material with wear tests, optical
microscopic evaluation, peel and bending tests, and SEM before we begin
soldering.
	A new high resolution ultrasonic transducer has been developed by
one of our suppliers that is capable of detecting voids in the solder layer
between the feltmetal pad and the TF finger.  Using this technique to
qualify the TF solder joints will eliminate the need for periodic destructive
peel tests.
	We have begun silver plating of the lower TF core fingers.  The
platers will move to the upper fingers next where both copper and silver
must be plated.  The second electroforming run on the upper TF core finger
has been completed.  We are removing the fixture so that cleanup
of the joint can proceed.  A third electroforming run will be required.
	Reassembly of FMIT#4 is complete, and power testing is ready to
begin.  Once the transmitter is tested, we will begin testing the
remote operation controls.  The currently installed tube can produce enough
power for testing but is not reliable enough for plasma operation.  However,
two of our tubes will be repaired before plasma operation resumes.
	Preparations for the antenna are progressing.  The removal of 18
studs invessel has been completed. Cleanup of the vessel wall around the stud
locations still needs to be completed.  Discussions between MIT and
PPPL have been ongoing about the antenna flange and feedthroughs.  The
antenna and several PPPL collaborators have arrived on-site for initial
antenna fit-up invessel.
	We continued work on the DNB accelerator supply last week.  This
work included completion of one of the control panels and design of a second.
Hardware for testing  the controls on the bench was completed.  Work continued
on the fast control logic for the accelerator supply.
	Preparations continue for the C-Mod Ideas Forum to be held August 19-20
at MIT. Titles for presentations should be submitted to censabella@psfc.mit.edu
by this Friday, August 14. Information on the purpose and format of the
Forum can be found at http://www.pfc.mit.edu/cmod/forum98.html.
  

Travel and Visits:

	Professor Cy MacLatchy from Acadia University, Nova Scotia
arrived this week for his one-year sabbatical. Professor MacLatchy will be
participating in divertor/edge experiments on C-Mod. His initial research
will concentrate on video image-capture and 3-D tomographic reconstructions of 
impurity injection "plumes" produced by the gas-injecting scanning
probe system.
	Christopher Watts and Rex Gandy were up Monday and Tuesday from
Auburn to review progress on the new ECE mirror system and discuss topics
for upcoming C-Mod ideas forum.
	Dave Johnson from PPPL was here last week continuing work on the
X-point Thomson scattering experiment.  Gerd Schilling, Randy Wilson and
Dave Cylinder, also from PPPL, are here this week working on the new antenna
installation fitup.
	Steve Wolfe took part in the Conceptual Design Review for the NSTX
Control System, held last Thursday at PPPL.  Earl Marmar attended the
July 29th FESAC meeting in Gaithersburg, MD., and the DoE Energy Research
Strategy Plan Workshop, Chantilly, VA. on Aug 7 and 8.