Progress in spheromaks for power amplification and transfer to hypervelocity projectiles

Summary form only given. The goal of the spheromak program at Los Alamos is to develop a new scheme for accelerating material objects to hypervelocities. The design of a proof-of-principle (POP) experiment for demonstrating velocity gain is nearly complete, and construction is proceeding. Hydrodynamic simulations of the high explosives (HE)-driven wall compression indicate that a 3/8-in.-thick aluminum wall for the intended dome-shaped geometry for the POP experiment can be compressed, without rupturing, at a speed of about 3 km/s. Present efforts are geared to demonstrating wall compression while maintaining excellent vacuum conditions, with the wall interior coated with materials which would minimize contaminants from plasma-wall interactions. CTX spheromak parameters close to those needed for projectile velocity gain have been obtained in a cylindrical flux conserver of nearly the same size as that of the POP experiment. Factors impeding the simultaneous improvement of these parameters from the present values include plasma-wall interactions and magnetic-field dissipation dominated by the higher resistivity of the spheromak edge