From:
irby@PSFC.MIT.EDU
Reply-To: IRBY@PSFC.MIT.EDU
Subject: Alcator C-Mod
Weekly Highlights
Newsgroups: sci.physics.plasma
Alcator C-Mod Weekly Highlights
March 7, 2003
We continue
to complete invessel work in preparation for pumpdown.
Work also continues
on ICRF and Lower Hybrid MIE Project systems.
Machine instrumentation is
being brought back on-line.
Physics
-------
Stewart
Zweben, PPPL, gave a talk at the C-Mod physics meeting on edge
minority
heating for H-mode control. This talk described
how minority
heating near the edge of C-Mod plasmas might be used to
generate fast
ion loss and so control the edge radial electric field and
the H-mode
transition. Topics
discussed were: previous work, edge resonance
conditions, tentative experimental
plans, diagnostics and analysis.
Initial simulations of Er by C. S. Chang
were also discussed.
Operations
----------
Work
has concentrated on invessel work this week as we approach
pumpdown. The J-Port horizontal flange has been
reinstalled and
installation of the antenna will begin as soon as all the
rf vacuum
feedthroughs are installed and leakchecked. We continued work on the
MHD antenna,
glow discharge cables, invessel alignments, and
installation and testing
of invessel cabling. The machining of
the
new BN tiles for the J-Port antenna has been completed.
We
continue the migration from VMS based to linux based data
acquisition
software. Data system diagnostic
routines used on the VMS
based system now work under linux. Data highways and user software
are
being tested and prepared for full data acquisition shot cycle
tests.
Machine
instrumentation is coming back on-line in preparation for pumpdown,
vessel
bake, cooldown, and ECDC. Machine
information is again being
trended to the MDSplus tree.
Lower
Hybrid MIE Project
------------------------
At MIT, we continue
to bring transmitter protection and control
systems on-line in preparation
for high power klystron tests. The
data
acquisition equipment and software have been tested successfully. More
parts for the active controller
equipment chassis have been ordered,
as backplanes for the chassis are
being populated.
At PPPL, cleaning of the LHCD coupler ceramic
vacuum windows has been
completed, and the inner metallic surfaces are now
being copper
plated. The vacuum
waveguide assembly has been successfully inserted
into the port extension
for a trial fit-up. More polishing of the
launcher rails is needed for a
smoother surface finish and an easier
movement of the launcher. Mounting of standard waveguide
components
onto the rear waveguide assembly has started.
ICRF
Systems
------------
The process of developing a detailed cost
and schedule plan for the
fast ferrite tuner project has begun. Based on
response time and
required magnetic field, preliminary specifications for
the power
supply for the electromagnet have been developed. Measurements of the
ferrite losses are
underway.
MSE Diagnostic
--------------
All
fabricated components for the refurbished Motional Stark Effect
diagnostic
have been received at MIT. Shake
testing of the new mirror
support frame has confirmed that the mirror is
now capable of
surviving accelerations of 1700 g in both the longitudinal
and
out-of-plane directions, which far exceeds the expected
disruption-induced
accelerations. Final vacuum baking of
several
components will take place over the weekend. Final assembly,
installation, and
alignment will be performed on Monday, in
anticipation of close-up of
C-Mod mid-week.
The INCONEL 600 backup metal mirrors for the MSE
diagnostic are
in-process at PPPL.
Once machining operations are completed at PPPL,
the mirrors will
be sent to one vendor for polishing and then to a
second vendor to be
coated.
Travel and Visits
-----------------
Martin
Greenwald and Miklos Porkolab traveled to Washington DC to
attend a
meeting of the Fusion Energy and Science Advisory Committee.
The principal
issues at the meeting were a discussion of the 2004
budget, US ITER
participation, and the 35 year development plan.