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 28, 2003



Purging of the cryostat has begun in preparation for cooldown of the
machine which is expected to begin early next week. Testing of the
control coil prototype has been completed under hybrid control. Work
proceeded on ICRF and Lower Hybrid systems.


Operations
----------

The C-Mod shot cycle has been ported to linux in preparation for the
start of the next campaign. This port includes the automated
announcement system, the bigboard, and the action monitor. Cycle
tests of the full data system were also completed successfully this
week. The hybrid computer has been used to pulse the prototype
control coil and stray field measurements have been made around and
inside the magnetic shield designed to protect the pumping station
turbo pumps. Tests of the machine mounted control coils is expected
to begin next week. Cabling to the coils, the coil patch panel, and
coil case grounds were installed this week.

Installation of the new LN2 sump was completed on Friday and a GN2
purge of the cryostat was begun. Moisture levels below 200
parts/million are required before LN2 can be added to the sump, and
cooling of the machine can begin.

The flywheel inspection is going well. The tomographic ultrasound
test of the flywheel was begun on Thursday. We expect the inspection
to be completed mid next week.


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

We continued to re-install transmission line components, DC breaks,
and other hardware required to supply power to the antennas. The #1
and #2 transmitters have been brought back on-line at the 1.5 MW level
into a dummy load. The #3 and #4 transmitters should become
operational next week. Design work continues on the fast ferrite
tuner.


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

At MIT, approximately 75 kW (of an eventual 250 kW) has been delivered
from a klystron into a dummy load for the first time using the HVPS.
The voltage from the supply was limited to 40 kV as we verify and
debug instrumentation.

At PPPL, very good progress has been made on the LH launcher. The
rear waveguide section is almost assembled, with supports, loads, and
patch panel connections to couplers, among other components, also
being installed. The support/sliding structure for the front shroud
assembly has been checked out with temporary hardened steel rails. The
launcher successfully passed its leak check on the vacuum test stand.
Stellite bearing surfaces are being prepared for replacement of the
steel, after which the tests will be repeated before delivery to
MIT. The front couplers have been completed and are now being leak
checked prior to installation on the shroud assembly.