Alcator C-Mod Weekly Highlights
			February 23, 2001
 

We continue to work on modifications to the J-Port antenna, improvements
to the J-Port fault protection systems, the DNB and related diagnostics,
and the Lower Hybrid Project.


ICRF Systems
------------

The J-port antenna modifications  have been designed and the longer lead
items have been detailed.  The schedule driver is the manufacturing of the
new striplines.  An aluminum prototype of one of the striplines was
produced by our EDM vendor,  and we are awaiting a second prototype to be
delivered 2/26.  The stripline return is being fabricated.  The new antenna
mounting hardware prototype has been successfully tested.  The Faraday
screen modifications have been tested, and we will begin to make the final
assembly next week.  The vacuum feedthrough ceramics have been reconditioned
and deburring the outer conductor has begun.

Fault indicator board construction for the new J-Port fault protection system
is complete and testing of the board has begun.  The first phase balance board
was also completed this week.  Cabling lists are being made up for this new
system.  We also continue to add instrumentation to make tuning of the
transmitters a more automatic operation.  Eight of eleven new tuning position
indicators for FMIT#4 have been installed. We plan to have FMIT#3
and  #4 ready for dummy load testing in early March in preparation for the
upcoming run period.  Inspection of FMIT#3 found an intermittent IPA output
cavity contact with damaged finger stock.  The system was refurbished and
reassembled and will be tested next week.


DNB
---

Automatic operation of the DNB will be required to fire the large  number
of shots needed to fully condition the beam.  Automatic operation was designed
into the software from the  beginning but has just been tested.  The initial
test was completed by firing many shots with only the filaments and the arc
in operation.  The latter was discharged into a dummy load.  Actual beam
conditioning will begin early next week.  The antenna pattern for the high
resolution ECE system is now being measured. This data will be used in
establishing the wavenumber  limits for fluctuation data. The saturation seen
in some of the data from the last run was traced to one set of IF amplifiers
which have since been repaired.


Lower Hybrid Project
--------------------

We have been working with MIT and their architects to define the
lower hybrid system water pipe routing.  The result is a recommendation to
re-route two ICRF transmission lines to make way for the water pipes.
Details were given to the architects on locations of the water loads to
facilitate the water manifold design.  This water system will provide
approximately 1200 gallons/minute of water at 200 psi to cool the klystrons
and associated equipment.  Work is also proceeding on the RF cart modifications
and wiring.  Drawings of the lower hybrid launcher have been provided by
PPPL and are being incorporated into our cell layout drawings to look
for any conflicts.


Inner Divertor
--------------

Tests are being performed on stud welding techniques that will be needed to
install the new inner divertor.  One vendor has slipped about 10 days in
the shipment of 150 upper transition tiles, but this delay does not affect
our installation schedule.  The rear girdle plate procurement is on
schedule.  Holes and slots have been milled in all the plates using
wire EDM. Machining of the ribs that key into and restrict motion of the tiles
is expected to start next week.  The C-Plates, the other major structural
component of the girdle, are being machined as one large ring that will be
cut apart to form the plates.  The machining of the inner radius is complete
and work is now proceeding to finish turning the outer radius cut.
Tiles, high strength bolts, and tile screw keepers are being cleaned and
prepared for installation.


Power Systems
-------------

The OH2L and the OH2U commutation switch capacitor bank work has been
completed.  Work is proceeding on the OH1 bank.


Data System
-----------

A new high performance server system was put into service this week to be
used for C-Mod data acquisition and between shot analysis. The previous
server will now be used to serve the operating system and user disk files to
C-Mod OpenVMS systems. The new server should significantly increase the
data handling capabilities of the data acquisition system. These  system
changes are essential to meet the increased throughput requirements of
new C-Mod subsystems such as the Lower Hybrid Project and diagnostics with
high data volume/rate requirements.


Travel and Visits
-----------------

Les Gereg and Joe Frangpani of PPPL visited this week to help with antenna
modifications and fit ups and reconditioning the vacuum feedthroughs.