 |
 |
 |
Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
(on assignment at Princeton Plasma Physics Laboratory)
W. Reiersen, S. Kaye, S. Jardin, J. Menard,
D. Gates, J. Robinson, F. Dahlgren, L. Grisham,
D. Majeski, D. Mikkelsen, M. Ono, J. Schmidt,
J. R. Wilson, R. Woolley
Princeton Plasma Physics Laboratory, Princeton, NJ 08543, USA
TSI Research, Inc., 225 Stevens Avenue, Suite #203, Solana
Beach, CA 92075, USA
Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
University of Wisconsin, Madison, WI 53706, USA
University of Texas at Austin, Austin, TX, USA
X. Wang
University of California, San Diego, La Jolla, CA 920-93-0417, USA
Abstract. The scientific parameters and the technology issues for a modest-size
Spherical Torus (ST) at 10 MA in plasma current are discussed. This class of
devices include a D-T-capable ST experiments (DTST,
R0 = 1.2 m) for
Proof of Performance for limited pulse lengths and neutron fluences, and a
steady-state volume neutron source (VNS,
R0 = 1.1 m) for testing Fusion
Energy Components to high neutron fluences. The scientific issues of interest
to the DTST include noninductive ramp up of plasma current in a limited time
scale (
40 s), confinement needed for high-Q burn, behavior of
energetic particles, physics and techniques to handle intense plasma
exhaust, and the
possibility of high performance plasma regimes free of disruptions or large
disruption impact. Also of interest to the VNS would be steady state operation
using large external current drive possibly at a modest Q ( 1-2)
achieving significant neutron wall loading (
1MW/m2 ) and a
configuration relatively amenable for remote maintenance. A much longer time
scale would be permitted for noninductive current ramp up. The center leg of
the TF coils, possibly multi-turn for DTST and necessarily single-turn for VNS
without significant nuclear shielding, is a technical and material issue of
unique importance to the ST. Positive-ion Neutral Beam Injection (NBI) and
HHFW (80 MHz) heating and current drive systems already available to
date are likely adequate for the DTST following pulse length extension to
50 s. For the high densities needed for enhancing the neutron wall
loading (to a few MW/
m2 ) in a VNS, a negative-ion NBI system
may become desired. Given an adequate physics database, the remaining enabling
technologies needed by the VNS appear largely similar in nature to those of
the ITER EDA design.
IAEA 2001
