F. Najmabadi , S. Jardin 4, M. Tillack ,
R. Miller , T. K. Mau , R. Stambaugh 3,
D. Steiner 5, L. Waganer 2, and the ARIES
Team
University of California, San Diego, La Jolla, CA,
United States of America
2 Boeing,
3 General Atomics,
4 Princeton Plasma Physics Laboratory
5 Rensselaer Polytechnic Institute
Abstract
Recent experimental achievements and theoretical studies have
generated substantial interest in the spherical tokamak concept. The
ARIES-ST study was undertaken as a national U.S. effort to investigate the
potential of the spherical tokamak concept as a fusion power plant and as a
vehicle for fusion development. The 1000-MWe ARIES-ST power plant has an
aspect ratio of 1.6, a major radius of 3.2 m, a plasma elongation (at 95%
flux surface) of 3.4 and triangularity of 0.64. This configuration attains a
of 54% (which is 90% of the maximum theoretical ). While
the plasma current is 31 MA, the almost perfect alignment of bootstrap and
equilibrium current density profiles results in a current-drive power of
only 31 MW. The on-axis toroidal field is 2.1 T and the peak field at the TF
coil is 7.6 T, which leads to 288 MW of Joule losses in the
normal-conducting TF system. The ARIES-ST study has highlighted many areas
where tradeoffs among physics and engineering systems are critical in
determining the optimum regime of operation for spherical tokamaks. Many
critical issues also have been identified which must be resolved in R&D
programs.
IAEA 1999