Alcator C-Mod Weekly Highlights
                        May 3, 2010


FY2010 weeks of research operations
   Base Target: 13 weeks
   Base Completed: 9.7 weeks
   ARRA Target: 5 weeks
   ARRA Completed: 5.0 weeks
   Plasma Shots: 1630


Operations
----------

Work continued on the MIT funded alternator cooling upgrade last week.
The plate and frame heat exchangers and the two 15 horsepower water
pumps were received and are in location. Installation of water piping
continues.  A number of electrical conduits have been installed between
the alternator house the river water pumping room.

In-vessel calibrations and preparations for flux loop refurbishment
continued.  Fabrication of new molybdenum tiles is proceeding.

We have performed particle induced X-ray emission (PIXE) analysis on
tiles from the GH, AB, and JK divertor modules to quantify deposition of
tungsten and other impurities.  Tungsten deposition was observed on all
of the tiles on the AB module which likely resulted from the tungsten
tile delamination and melt near this location.  A large amount of
tungsten was observed on the leading edge of the GH module and a smaller
amount was observed on the trailing edge of the JK module.  Tiles that
were pre-coated with 75 um boron layers showed significant variations in
their surface properties from tile to tile, with many showing signs of
boron delamination.


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

Phase adjustment shims for controlling the column to column waveguide
phasing have been installed in the Jungle Gym (external waveguide
splitter) assembly. The Jungle Gym was re-calibrated after installing
the shims, and the calibration shows an average column to column phase
error of 0.7 degrees with a maximum of 3.0 degrees.  The klystron
set-points generator and post-shot analysis programs have been updated
with the new calibration data.

We continued development of Coupler and Transmitter Protection System
components and firmware.


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

High power tests of the vacuum feedthroughs needed for the Advanced ICRF
Antenna continued last week.  Three of the five feedthroughs have now
been successfully tested.  Initial tests of the Master Fault Processor
CPLD board indicate it is properly handling fault conditions.  FMIT#3 is
being re-tuned from 70 to 78 MHz in preparation for continuing the
FY2010 run campaign


Diagnostics
-----------

The new MSE shutter was successfully exercised (1500 cycles) under
vacuum and at temperature (150 Celsius) to prove its reliable
performance under C-Mod operating conditions.  The new MSE optical
housing was installed in-vessel and aligned.  Working with two visiting
optical experts from the University of Arizona Polarization Laboratory
(Steve McClain and Mike Dalpiaz), we performed several optical tests on
the MSE optical system to look for potential vignetting problems, using
the newly commissioned MSE calibration machine.  Initial analysis
suggests that there are no significant misalignments or other issues
with the MSE optical system.


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

Dennis Whyte, Amanda Hubbard, Bruce Lipschultz and Earl Marmar traveled
to PPPL on April 30 for collaborative discussions on research
requirements for plasma-material interactions, fusion nuclear science,
and fusion pilot plants. Dennis Whyte presented a seminar on "Taming the
Plasma Interface as the Next Frontier: An opportunity for US
leadership."

Martin Greenwald was in San Diego last week serving as a member of the
the DIII-D Program Advisory Committee.

Stewart Zweben, PPPL, was at MIT last week to discuss his upcoming PSI
paper on the "Relationship of Edge Turbulence to SOL width".  He worked
on a code for GPI blob tracking to help separate the convective from
diffusive radial flows, and helped with the GPI calibration.

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