From:
WOLFE@PSFC.MIT.EDU
Reply-To: WOLFE@PSFC.MIT.EDU
Subject: Alcator
C-Mod Weekly Highlights
Newsgroups: sci.physics.plasma
Organization:
MIT
Alcator
C-Mod Weekly Highlights
Oct.
30, 2000
Last week was a maintenance period at Alcator C-Mod. No plasma
operations were
scheduled.
Operations are scheduled to resume
this week.
Engineering
------------
A quick vent of
the vacuum vessel, with helium backfill, was performed in
order to
reconnect the diagnostic neutral beam system, which had been removed
following
a loss-of-vacuum accident in September. The repair to the DNB
beamline was
completed last Thursday. A new bellows protection shield was
installed,
along with additional beamline instrumentation, to prevent similar
incidents
in the future. C-Mod was pumped back down Thursday afternoon and a
low
temperature bake at 60C begun. On
Friday, the bake was brought up to 100C
and continued at this level over
the weekend.
The TF and PF busses were configured for reversed-field
and current operation,
in preparation for experiments to be carried out
beginning this week. New
power system instrumentation and interlocks were
also added in support of
upcoming testing with increased pulse lengths.
The new instrumentation will be
tested and debugged in parallel with
normal machine operation. Long-pulse
engineering tests are scheduled for
the end of November.
ICRF System
-----------
The
J-port ICRF antenna feed lines were returned to a two-strap
configuration,
with the center pair of current straps energized as a
dipole and the outer
straps grounded. The antenna will be run in this mode
for the next series of
plasma experiments.
Lower Hybrid
Development
------------------------
We have been working for
the last few weeks on the design of the low power RF
system, and phase and
amplitude real-time control of the klystrons.
Two more
klystron carts have been returned to MIT from PPPL. Four klystrons can be
mounted on each
cart. A third cart is back in-house
after being sent out to
be cleaned and enameled. This cart is now ready for the re-installation of
sockets,
power supplies, water cooling equipment, etc.
Visitors and
Travel
-------------------
Most of the C-Mod physics staff
participated in the APS Division of Plasma
Physics Meeting in Quebec City
last week. Forty-two papers describing C-Mod
research, including three
invited talks, were presented.
Dr. K. Ushigusa, leader of JT-60U
Experimental Division I, visited C-Mod last
week for discussions under the
U.S.-Japan collaboration agreement on
High-Density Operation in Alcator
C-Mod. Dr. Ushigusa met with Bruce
Lipschultz, Jim Irby, and Steve Wolfe
of the C-Mod team.