From:
irby@PSFC.MIT.EDU
Reply-To: IRBY@PSFC.MIT.EDU
Subject: Alcator C-Mod
Weekly Highlights
Newsgroups: sci.physics.plasma
Organization:
MIT
Alcator
C-Mod Weekly Highlights
March
15, 2002
Machining of the retaining cylinder was completed
this week. Installation
of the
upper TF horizontal arms is also complete.
The new RFX diagnostic
neutral beam is operational.
Physics
-------
Pedestal
comparison experiments continued on Thursday and Friday at
ASDEX-Upgrade. This series of discharges aimed to match the
dimensionless
parameters of some 1 MA EDA H-modes on C-Mod; previous
experiments were at
lower current.
Despite fairly good matches to the shape and plasma
parameters,
the AUG H-modes were either ELMy or
ELM-free. Detailed analysis
of
profiles and fluctuations will be carried out during the upcoming
AUG
maintenance period.
Operations
----------
All
machining of the retaining cylinder is complete. It is now
being prepared for installation. All upper TF horizontal arms have
been
installed and the springplates inserted.
Modifications to the
cryostat have been completed by our
vendor. We expect the cryostat to
be
back on-site by early next week in time for fitups of the new boots
needed
to seal the cryostat to the vessel ports.
Preps to the horizontal
vacuum flanges continue as we prepare them
for installation with the new
boot configuration. The new F-Port
flange
welding is nearly complete.
The upgrade to the
alternator varistor bank has been completed.
The MIT funded work on the control room is making good
progress. The old
control room
wall has been removed, new doors installed, new AC units
hung, and the
support hardware for the new ceiling tiles is in place.
Lower
Hybrid MIE Project
------------------------
The fabrication of
components for the lower hybrid launcher is on schedule.
The vacuum shroud
and interface flange have been completed by the vendor
and are being
shipped to PPPL. The 5 final couplers
are EDM'd and ready for
brazing to
commence on site pending delivery of the ceramic windows. Testing
on the prototype waveguide is
proceeding; some adjustment may be
necessary
to optimize the splitting configuration. Drawing packages are continuing to
be
collected for RFQ packages in anticipation of accelerated funding.
High
voltage wiring and connections to the klystrons has begun and
transmitter
control wiring continued.
ICRF Systems
------------
The
stub tuner and phase control box fabrication was completed this
week. Work
has begun on changes to the PLC software to control these
new
systems. We continued to work on
improvements to the rf control
and fault systems.
All machining
and polishing operations on the J-Port antenna straps
have been completed
and we are preparing to send them out for
re-plating. We have begun final grinding operations on
the D and
E-Port antenna Faraday screens.
DNB and Related
Diagnostics
---------------------------
The RFX Beam was
operated this week at 50 kV and 4A, with 50 ms pulses.
A very large effort
by the Russian visitors, and Texas and MIT personnel
was required to bring
on line in such a short time the power, vacuum, and
control systems needed
to operate the beam. The DNB camac
crate and highway
have been brought back into operation in preparation for
synchronization
tests and for measurement of the component mix next
week.
Polishing of the BES fibers was completed this week. New ferrules for the BES
optical fibers
have also been completed. Ferrules for
the MSE fibers are
still being fabricated.
Diagnostics:
------------
The
132 GHz channel of the upgrade to the reflectometer is operational at
PPPL,
and bench tests are continuing.
The Gunn diode frequency can be varied between
128 and 136
GHz. The 140 GHz channel, originally
intended to be another
swept channel, has been converted into a fixed frequency channel until
its
Gunn diode can be repaired.
All components are in-house for
the MHD antenna and assembly is in
progress. We continue to develop a prototype amplifier to drive the
antenna.
Travel
and Visits
-----------------
Miklos Porkolab, Ian Hutchinson,
Earl Marmar, and Ron Parker attended
the
FY2004 Budget Planning Meeting in Gaithersburg, MD, on March 12,13.
The
Alcator C-Mod presentation for this meeting may be found at
http://www.psfc.mit.edu/people/censabella/bpm_2002_presentation.pdf
Earl
Marmar also attended the FFCC meeting on March 14 at Gaithersburg.
Martin
Greenwald travelled to Oberlin College this week to give a talk on
"Turbulence
and transport in magnetic confinement experiments" as part of the
APS
distinguished lecture program. Martin
also travelled to PPPL to attend
the ITPA meeting on global confinement
and modelling. Plans for
migrating
the profile databases to MDSplus were discussed.
Tom
Fredian presented MDSplus tutorials at three ITPA workshops held at GA
and
PPPL over the last three weeks. The tutorials focused on the MDSplus
remote
access to the ITER Profile Database now being stored in MDSplus
format in
Culham, England.