Alcator C-MOD Weekly Highlights
					Dec. 16, 1993

The scheduled shutdown is continuing, with good progress in all areas. 

Inspection of horizontal port inner seals is continuing. Likely causes of
small vacuum leaks associated with rapid LN2 cooling during the last run
period were identified. Tests of new insulating blanket for the vessel inner
seals were completed.  

Inspection of the cryo-system, including LN2 pump, inlet and exhaust tubing,
and all associated filters, continued this week. A test fit up of the new LN2
feedline was begun. Old feedline has been removed from bus tunnel.   The bus
tunnel panels were modified to provide a more reliable seal to GN2 during
machine operation.

In work inside the vessel, final measurements were made on tile module
movement relative to the vessel.  Removal of EF1 modules is in progress.
Fabrication of new anti-torque pins, and the associated bending fixture, and
of replacement tiles, has begun.

Tests were completed on new iso-amplifiers for bus instrumentation and Hybrid
feedback signals.  The new amplifiers have much improved CMRR and frequency
response compared to the LLNL boards now in use.  Layout of the circuit boards
has begun.  They will be board for board replacements of the old boards.

Some bolts associated with the OH bus system needed to be replaced since the
heads stripped when attempts were made to re-torque them to specification. 
These will be replaced with high tensile strength bolts with larger heads.

The first ICRF HVDC supply is back in place and has been reconnected; it had
been removed to accommodate the crane used to install the 75-ton flywheel.
The crowbar unit for the second FMIT transmitter has been installed in the
power room. 

Analysis software is being successfully ported to the new Alpha (AXP 3000/400)
workstations. A modifification to EFIT using all public-domain software has
been obtained from GA and tested on both the VAX 4000/90 and the AXP. On the
AXP a typical test case took 220 seconds (elapsed time) for 60 time slices,
compared to 476 seconds for the older code on the VAX, a little better than a
factor of two improvement. The TCI analysis software used for interpretation
of interferometer data has also been moved to an AXP, with somewhat greater
speedup. 

The Alcator C-MOD SUMMARY database, which contains up to approximately 30 scalar
quantities for each shot, and is intended for use in identifying shots for
detailed analysis and for observing trends and correlations, is being revised
and expanded. Over 2000 entries from the 1993 run period will be included.
This database was originally populated automatically following each shot, and
is now being revised using improved software for calculating some quantities
and by adding additional quantities that had not been routinely calculated
previously.

A workshop on divertor and edge plasma characteristics was held at MIT on
December 13-14, involving physicists from DIII-D and Alcator C-MOD. The
purpose was to better  understand the differences and similarities of the edge
and divertor plasma characteristics in C-Mod and DIII-D, and to identify
topics for future research and potential collaborations. 

---------------------------------------------------------------------------------
The Alcator C-MOD weekly highlights report is now being sent via e-mail to
people who have expressed interest in the Alcator program. If you do not wish
to receive this report, or if you know of someone who would like to be added
to the mailing list, please contact WOLFE@PFC.MIT.EDU.