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 29, 2002


Assembly of Alcator C-Mod continued this week with installation of the
TF legs. Work on the Lower Hybrid MIE Project and RFX DNB continued.


Operations
----------

All TF vertical legs are now installed. The TF magnet will be completed
next week as soon as the remaining springplates are installed. Final prep
work on the cylinder was completed this week as was a successful dye
penetrant test of the areas we had machined.

MIT funded contract work on our control room should be finished next
week. Preparations are being made to bring up computer, data acquisition,
and control systems as soon as this work in done. The electrical wiring
for the new air conditioning units in the C-Mod cell has been completed,
and water cooling lines are being installed.


Lower Hybrid MIE Project
------------------------

AC wiring to the equipment racks was completed this week, and the equipment
rack for Cart #3 was powered up for the first time. The fiber-optic cables,
which were recently terminated, were connected at the HV junction box, the
pump controller, the control computer, and the #3 transmitter Cart.
The PLC rack for Cart #3 was also powered up. Communications were
established between the control computer and transmitter #3.
The DC supply for transmitter #3 was turned on and the TPS faults were cleared.
Operation of the pump enabled fiber optic signal to the pump controller
to be checked. Fabrication of the fiber optic interface for transmitter
#3's rack was completed. The RG-220U HV cable was routed and
terminated between the junction box and cart #3, and the junction box side
was un-installed to allow HVPS commissioning to continue.

At PPPL, pins have been added to the prototype LH coupler to improve the
alignment of the components and reduce reflections. The coupler performance
should now perform to specification.


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

All machining and prep work has been completed on the J-Port antenna
straps. They will be copper plated next week. All polishing work has
been completed on the D and E-Port antenna backplanes which will also
be copper plated next week. Machining has begun on the new boron
nitride tiles needed for both antennas.

We continued testing and calibration of the new phase demodulator
boards. New fault detector PC board prototypes are in house
and ready to be populated.


DNB and Related Diagnostics
---------------------------

We continued to operate the beam throughout the week adding
diagnostics (beam component mix and pressure measurements), and
continuing the development of the vacuum system PLC. The beam is
operating well and comes quickly to full voltage and current after only
a few shots. We are preparing for the first regeneration of the cryo
pumps.


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

The MHD antennas have been re-welded to correct misalignment of support plates
that occurred during a welding operation by one of our vendors. Fitups of
both the coils and the tiles are now acceptable. Work also continued on the
power supplies and amplifiers required to drive the antennas.

Work continued this week on new scanners for the TF resistance and
invessel thermocouple measurements. Work also continued on the
CXRS telescope and shutter, and the MSE fibers and optical
components.


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

David Mikkelsen, PPPL, spent the week with the C-Mod group discussing
details of the experimental measurements, with particular attention to
the uncertainty in the electron temperature gradient.

Peter Koert spent the week in Germany reviewing progress on the fast
ferrite tuners and gathering documentation needed to design the control
circuitry.