Spherical stellarator approach

Summary form only given. In this report, we present the results on the novel ultra low aspect ratio stellarator system with A=1.05-2, that can be called a spherical stellarator (SS) in analogy with the spherical tokamak (ST) concept. Coil configuration of SS features the central stack and differs from that of ST by inclination of external parts of the toroidal field coils. A few potential advantages of the SS configuration, over other approaches in magnetic confinement fusion, can be summarized as follows: (a) very compact design offering the low cost approach, (b) closed vacuum flux surfaces and no need, in principle, in the ohmic current transformer, (c) simple modular coil system, (d) easy access to the plasma, (e) more area for heat removal and the tritium breeding blanket in a reactor, (f) simple toroidally symmetric divertor, (g) enough space between the central stack and the plasma surface to put the blanket and protect the stack from intense fluxes of particles, heat and neutrons.