Alcator C-Mod Weekly Highlights
			Jan 20, 2004

Last week at Alcator C-Mod was primarily a maintenance week. One plasma run
was scheduled in order to complete experiments using the PSI fast camera,
which is being returned to PPPL for use on NSTX. Progress continued on the
ICRF and Lower Hybrid Systems.

Plasma Operations are scheduled to continue this week, with resumption of ICRF
operation (FMIT#1 and 2) planned on Thursday.

Operations
------------

One plasma run day was scheduled and completed; a total of 21 plasma
discharges were produced with a startup reliability over 85%. This run was
principally devoted to completing MP#319 "Experimental/Theoretical Comparisons
of SOL Turbulence in Alcator C-Mod", which partially relies on the PSI 300
frame, 250kHz camera to image turbulent structure near the separatrix. This
camera is being shared with NSTX and was returned to PPPL at the end of the
week. Tne run, carried out on Thursday, had three main objectives: study of
edge turbulence approaching the density limit; poloidal propagation of
turbulent structures (blobs) in lower and upper single null discharges: and
edge turbulence characterization in helium discharges. All three sets of
experiments were completed. In addition, one hour (five shots) was devoted to
beam-into-gas-with-field (no plasma) shots in support of calibration of the
MSE diagnostic.

ICRF System
-----------

The investigation into the cause of the fault in the FMIT#4 on Jan 9
continues. At present, the root cause appears to be a failed firing circuit in
the vacuum breaker in the high-yard. Repairs to the damaged units are
underway. A review of the incident has been scheduled for this week.

Upon completion of a procedural review on Tuesday, FMIT#1 (D-port), which had
a new high power tube installed last week, will be conditioned in preparation
for operation on Thursday. FMIT#2 (E-port) is also expected to be ready for
operation on Thursday, after adjusting the tuning of the driver output and FPA
input to account for a change in the length of the transmission line between
the two cavities. This change was made to facilitate access to the FMIT#1 FPA
tube.

Lower Hybrid System
--------------------

A teleconference was held on 1/14 to discuss progress toward completion of the
repair of the C-Mod lower hybrid launcher.  A detailed schedule presenting all
remaining tasks involving repair, testing, and installation on C-Mod was
presented and discussed.  Final machining of the Forward Wave Guide flange
was completed by the vendor.  All dimensions have been rechecked at PPPL, and it
will be returned to MIT for fitup with the Rear Wave Guide on 1/19.  PPPL
personnel will work on the assembly at MIT.  Bob Childs (MIT) has obtained
temperature profiles of the brazing vendor's furnaces in preparation for the
LH Coupler window braze; they appear to be quite good.  MIT is also in contact
with an additional, local, brazing vendor for added input to this critical
ceramic-to-titanium braze.

Installation of the circulators continued this week. All twelve are now
physically mounted. The remaining copper RF gaskets required for hookup have
arrived onsite, as have 16 of 24 water-cooling lines.

Travel and Visitors
-------------------

Stewart Zweben (PPPL) was at C-Mod this week to participate in turbulence imaging
experiments.