Physics assessment of stellarators as fusion power plants

Four different stellarator configurations (a compact torsatron, a new modular torsatron, Helias, and a new modular Helias-like heliac) were analyzed as fusion power plants and compared with the second-stability ARIES-4 tokamak. The device and plasma parameters were determined by minimizing the projected cost of electricity subject to various constraints. The stellarators were competitive with ARIES-4 for a range of assumptions on confinement models, alpha-particle losses, and beta. One dimensional power balance equations were solved for both Lackner-Gottardi confinement scaling with an assumed n(sub e)(r) and for helical-ripple-induced transport with both assumed and calculated forms for n(sub e)(r) and E(sub r)(r).