Feasibility of Radio-frequency Pre-ionization in a Non-equilibrium Disk MHD Generator

Abstract

The feasibility of radio-frequency (_??_ MHz) pre-ionization is examined in a non-equilibrium disk MHD generator channel under no externally applied magnetic field with γ-z two-dimensional numerical simulation. Non-equilibrium seeded plasma with electrical conductivity sufficient for high power generation can be realized in the supersonic nozzle where the electric field is induced almost uniformly by the induction coils. The radio-frequency electric power required for the pre-ionization becomes less with the decrease in the seed fraction. The ratio of the required electric power to the thermal input of generator channel is of the order of 10^-3_??_10^-2. The effects of induction coil current and frequency on the plasma properties are also discussed.