Long pulse tokamaks using high performance resistive magnets

Engineering aspects of tokamak designs which could address the physics of long-pulse hydrogen/deuterium operation and alpha-particle-dominated heating (Q>5) are presented. The main characteristics of these designs are their relatively small size, their resistive toroidal field coils, and their long pulse capability. In D-T operation this machine could satisfy the basic physics requirements for the ITER (International Thermonuclear Experimental Reactor) physics mission at a much lower cost than the present superconducting ITER design. For these designs, demountable TF (toroidal field) coils similar to Alcator C-MOD are considered, and steady-state water cooling of the magnets is investigated. The demountable nature of the TF magnet simplifies the assembly and maintenance operations. Internal poloidal field coils minimize this system and increase its flexibility