Alcator C-Mod Weekly Highlights
             October 29th, 2007
				

FY2008 weeks of research operations:
     Target: TBD
     Completed: 0 weeks


Physics
-------

Measurements of plasma potential in the presence of ICRF for an emissive
probe located at the AB limiter were investigated as a function of ICRF
power, boronized vs un-boronized walls, with molybdenum vs BN antenna
limiter tiles, and confinement mode.  In L-mode, the plasma potential
scaled with ICRF power for an un-boronized machine and with the square
root of ICRF power in the boronized case.  The increase in plasma
potential with ICRF was present even with the BN installed on the ICRF
antenna limiters.  Finally, the plasma potential was higher in H-mode
for given ICRF power compared to an L-mode discharge.


Operations
----------

The alternator and flywheel seal oil heat exchanger maintenance was
completed last week.  Engineering systems required for pump-down, bake,
cool-down, and ECDC are being brought back on-line in preparation for
operation as soon as in-vessel work is complete.  A new thermocouple
scanner for the CRYO system will be ready to test as soon as programming
of a CPLD (Complex Programmable Logic Device) is complete.


In-vessel Work
--------------

The MSE collection optics cannister has been re-installed in-vessel.
The new lens supports should be more resistant to stress induced
birefringence and able to better survive disruptions.  Calibration of
the new optical system was begun over the weekend.

The new outer divertor edge tiles needed to replace tiles sent out for
analysis have been installed. The outer divertor cover plates have also
been reinstalled.

Re-installation and spatial and transmission calibration of the
wide-view CXRS optics has been completed. Repairs on the toroidal
shutter were also completed. The wide-view CXRS system is now ready for
pump-down.

We have completed installation of the polarimeter shutter, and alignment
checks of the polarimeter beam-line are now underway.  Completion of the
alignment checks will allow re-installation and spatial calibrations of
the NESOX and bolometer diagnostics to begin. Collection optics for the
visible bremsstrahlung array have been re-installed.


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

Following a successful test of the rf gasket compression, the forward
and rear waveguide stacks were joined on Wednesday of last week.  The
new gaskets are plated and conform well to the mating surfaces.  The
jungle gym components have also been installed, and a phase calibration
of the launcher has been completed.  The launcher is now ready for
installation.


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

The high voltage breaker for FMIT#1 was returned to service last week
following replacement of a solid-state relay.  FMIT#1 has now been tuned
and run into a dummy load, and the new demodulators for this transmitter
have been successfully calibrated.


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

Catherine Fiore attended the semi-annual meeting of the APS Committee on
the Status of Women in Physics, held in Detroit on 10/22/07.

Paul Bonoli and Ron Parker had discussions with Yves Peysson and
Dr. Joan Decker from Cadarache on October 23, 2007 while they were
visiting the PSFC. They discussed simulations and measurements of hard
x-ray spectra during lower hybrid current drive experiments on Alcator
C-Mod.

Ron Parker served on the Scientific Council reviewing the fusion program
at CEA Cadarache, exclusive of ITER, on October 10,11 2007.  Ron has
also agreed to serve on the European Facilities Review Panel in
preparation of the next 5-year plan for fusion development in Europe.

Martin Greenwald was in Washington to attend a meeting of the Fusion
Energy Sciences Advisory Committee and to deliver a panel report on long
range planning.  Miklos Porkolab also attended the meeting.


Correction to 10/15 Weekly Highlights
-------------------------------------

Two weeks ago we incorrectly attributed funding for the new PSFC
computer cluster.  Funding in approximately equal amounts comes from
C-Mod (DoE), Theory (DoE), and PSFC New Initiatives.


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