Alcator C-Mod Weekly Highlights

                   Alcator C-Mod Weekly Highlights
                          September 15, 2003



Work continued on Lower Hybrid and ICRF system last week.  Reassembly
of the alternator is scheduled to be completed this week.  The C-Mod
Ideas Forum was held last week at MIT.


Ideas Forum
-----------

The C-Mod Ideas Forum was held on September 10, 11, and 12 to aid in
planning the FY04 C-Mod operating campaign.  The purpose of the Forum
was to provide an opportunity for presentation of specific ideas
appropriate for experiments during the campaign. The Forum was open to
all interested parties, including current and potential future
collaborators.  The agenda of the Forum and links to the ninety-eight
presentations can be found at

http://www.psfc.mit.edu/people/terry/Ideas_Forum_2003/forum_agenda.html

Ideas were submitted by personnel from PPPL, U. Texas, U. of
Wisconsin, IPP-Garching, LANL, GA, RFX, LLNL, ORNL, CRPP, and MIT.
Follow-on meetings of the Topical Science and Integrated Thrust
Groups, in the coming few weeks, will determine initial prioritization
as the next step leading to mini-proposal generation and run-time
allocations.


Operations
----------

NSTAR opened our primary 13.8 kV breaker last week for annual
maintenance.  During this time, in preparations for plasma operations,
we performed inspections and maintenance on much of the hi-yard
equipment, including vacuum breakers and instrumentation.

Completion of all C-Mod vacuum work is expected by the end of this
week, after which a final pumpdown and leak check will be performed.
Cool down, bake, and ECDC activities will then follow, with first
plasma operation expected in early October.


Alternator
----------

GE repeated the DC stepped voltage test to 28 kV on the alternator
stator last Monday.  This test was followed by a hi-pot proof test to
36.7 kV.  All stator windings passed these tests with excellent I/V
characteristics.  As a final test of the stator windings, an AC hi-pot
to 21.6 kV RMS (a factor of 1.5 above the working voltage) was done by
GE on Wednesday.  The results were again very positive and GE has
recommended the alternator be returned to service.  AC hi-pots are
considered to be the most probative tests of the stator windings and
an excellent predictor of safe in-service operation.

With the concurrence of DoE OFES and the MIT Vice-President for
Research, we have instructed GE to proceed with reassembly, which has
now begun.  GE is using a two shift schedule and expects to be
finished by the end of this week.  Installation of the drive motor,
instrumentation, and other support hardware by C-Mod personnel will
require one additional week.


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

General maintenance of transmitters, control electronics, and switch
gear continued.  Preparations of the control system instrumentation
for 50 MHz operation began.  Reassembly of transmission line
components in the C-Mod cell continued.


Lower Hybrid Systems
--------------------

The modified PLC and operator interfaces have been installed and
tested on the LH system. Some programming bugs were located and
corrected.  Measurements of the PLC analog inputs will be made and
calibration factors will be determined.

The Lower Hybrid Forward Wave Guides have now been reassembled at
PPPL.  Loss measurements have been performed, and the losses are
acceptable.  The upper FWG will be brought to MIT on Monday for
high-power RF tests; Nevell Greenough (PPPL) will participate in the
testing.  Both MIT and PPPL are continuing to refine and compare
finite element analysis mechanical/thermal models of the coupler.
Measurements of the coefficient of thermal expansion of both the
ceramic and titanium coupler materials have been started, and the
results and differences in measurement techniques are being discussed.
Coupon tests of braze materials are underway, and final preparations
are being made to remove the "old" ceramic windows from the existing
coupler which is expected to take place next week.


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

Martin Greenwald attended the 18th International Conference on
Numerical Simulation in Plasmas to deliver a review talk titled
"Beyond Benchmarking - How Experiments and Simulations Can Work
Together in Plasma Physics".  This review talk may be found at

http://www.psfc.mit.edu/people/g/icnsp03-talk.pdf

Several collaborators from PPPL were at MIT last week.  Stefano
Bernabei came to attend the C-Mod Ideas Forum on 9/11 and Stewart
Zweben visited from 9/8-12, also participating in the Ideas Forum.
Gerd Schilling was at MIT from 9/9-12 for the Ideas Forum and Lower
Hybrid program discussions.  Martha Redi was at MIT on Sept 5, 8, and
9 to meet with Catherine Fiore, Steve Wukitch and others for
discussions about the RF ITB gyrokinetic simulation work and Ohmic
H-mode ITB data for upcoming publications and conferences.
  
Bill Rowan, U. Texas, also visited last week for the Ideas Forum.


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