Tokamak reactor designs as a function of aspect ratio

This paper assesses the technical and economic potential of tokamak power p lants which utilize superconducting coil (SC) or normal conducting coil (NC ) designs as a function of aspect ratio (A). Based on the results from plas ma equilibrium calculations, the key physics design parameters of beta (N), beta (P), beta (T), and kappa were fitted to parametric equations covering A in the range of 1.2-6. By using ARIES-RS and ARIES-ST as reference desig n points, a fusion reactor system code was used to project the performance and cost of electricity (COE) of SC and NC reactor designs over the same ra nge of A. The principle difference between the SC and the NC designs are th e inboard standoff distance between the coil and the inboard first wall, an d the maximum central column current density used fdr respective coil types . Results show that at an output power of 2 GWe both NC and SC designs can project COE in the respectable range of 62-65 mill/kW h at gross thermal ef ficiency of 46%, with neutron wall loading (Gamma (n)) similar to 7 MW/m(2) . More importantly, we have learned that based on the present knowledge of equilibrium physics and fusion power core components and system design we c an project the performance and COE of reactor designs at least for the purp ose of comparative assessment. Tokamak design points can then be selected a nd optimized for testing or commercial devices as a function of output powe r, A and Gamma (n) for both SC and NC design options. (C) 2000 Elsevier Sci ence B.V. All rights reserved.