Alcator C-MOD 
			Weekly Highlight Report
			June 24, 1993

Divertor plasmas are now being routinely produced. After some development
work on symmetric double null plasmas, we have mainly concentrated on lower
single null equilibria, with the plasma displaced below the midplane. 
Typical elongations are between 1.5 and 1.6.  The outer separatrix strike
point has been controllably scanned across the outer divertor target and
into the "slot". The flush-mount probes in the divertor structure are
operating, and show data consistent with the magnetics reconstruction of
the separatrix positions.

Marfes have been observed on several diagnostics, including the
tangentially-viewing plasma TV. The Marfe typically forms near the inboard
midplane. As the plasma is elongated and diverted, the Marfe tends to move
above the midplane, but remains on the inboard side.

The elongations obtained in the divertor experiments are near the maximum
that we have been able to control using line-commutating supplies. We have
observed vertical position oscillations with frequencies in the range of 30
to 80 Hz, often leading to a vertical disruption. Current decay rates as
fast as 0.5 MA/msec have been observed during these disruptions.

The GA chopper supply has been used to drive the EFC coils for the first
time this week. Today's run is being devoted to developing the techniques
to use this supply to control the vertical position and allow stable
operation at higher elongations. Initial results are promising.

The Michelson ECE system is now producing electron temperature profiles. 
Typical central temperatures derived from second harmonic cyclotron
emission are in the range of 1:1.5keV, with half-widths of about 11cm.
The HIREX diagnostic is giving ion temperatures from measured Doppler
broadening of (injected) trace argon.