The PROTO-SPHERA load assembly

PROTO-SPHERA is a proposed spherical torus where a hydrogen plasma arc, in a form of a screw pinch field fed by electrodes, replaces the central conductor. This simply connected magnetic configuration, if fusion relevant, might strongly simplify the design of a fusion reactor. The machine design philosophy, basic geometry and operating conditions together with the major components like the vacuum vessel, coils, electrodes, protection components, divertor, etc. are analyzed. The thermal and electromagnetic behavior as well as the predicted and permitted key stresses will be discussed in order to demonstrate that the design, construction and reliable operation of the machine are feasible. Reference is also made to the proposed Multi-Pinch experiment using the START vacuum vessel to demonstrate the feasibility and stability of the PROTO-SPHERA configuration.