Alcator C-Mod Weekly Highlights
			     August 4, 2008
				

FY2008 weeks of research operations:
    Target: 15 weeks
    Completed:  15.7 weeks



Physics
-------

Dennis Whyte, in collaboration with Valerie Izzo, UCSD, has developed a
NIMROD model to help understand runaway losses in LH-heated C-Mod
plasmas terminated with a massive gas injection. The model showed that
shortly after the LH-produced 100 keV suprathermal electrons were
accelerated to runaways in the thermal quench, the evolving stochastic
field quickly de-confined the runaways such that no runaway tail was
found in the current quench.  This result is in qualitative agreement
with the C-Mod experiments.  With further refinements, NIMROD could be
used as a predictive tool for runaway losses and amplification in ITER.


Operations
----------

Disassembly of C-Mod is nearly complete.  The OH Stack and TF core were
removed from the vessel last Thursday and placed in the middle of the
cell for inspection.  The PF magnet package cover plates were also
removed to allow inspection of these magnets to begin.

An MIT funded upgrade to our alternator battery backup system is now
underway to provide air conditioning for the battery bank and generator
room.

A meeting was held with General Electric last week to discuss details of
the alternator inspection that will begin this week.


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

We continued work on upgrades to the ICRF control system and design and
fabrication of the new IPA hardware.

A successful ICRF antenna review for the proposed 4-strap antenna was
held at MIT on July 30.  The external reviewers were Dave Rasmussen,
Phil Ryan, Rick Goulding, all from ORNL, Randy Wilson, PPPL, and Bob
Pinsker, GA.


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

Low power testing of the 4-way splitter prototype has begun.  Simulation
work has also begun that self-consistently models the 4-way splitter,
couplers, and the plasma.  This work will allow the launcher design
parameters to be well optimized.


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

Piero Martin, University of Padua, visited last week. He gave a seminar
on Tuesday entitled "At the cutting edge of RFP physics: high current
operation and real-time stability control in RFX-mod". He also had
discussions with E. Marmar, R. Granetz, S. Wolfe, and I. Hutchinson on
topics of mutual interest.

David Terry traveled to PPPL last week to serve as a member of the
review team for the DOE Facility and Operations Review of NSTX.  He was
also present for the DOE NSTX Five Year Plan Review debriefing.


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