Experiments on MHD Generators with Nonequilibrium Ionization Using Potassium-Seeded Argon Plasmas

Abstract

The results of a series of experiments aimed at the realization of nonequilibrium ionization in generators using magnetically induced ionization are described. The experiments were performed with two Faraday-type MHD generators, using potassium-seeded argon plasma in the temperature range of 1,600° to 2,000°K at about 1 atm. In the first experiment, the mechanical and the thermal performances of the generator channel and also its electrical characteristics were observed in quasi-equilibrium state, the results of which indicated satisfactory operation. In the second experiment, the electrical characteristics of the generator with an improved configuration were measured. The experimental results were explained with use made of the four-terminal network theory which involves the nonequilibrium ionization and instability effects, and the experimental results agreed well with theory. Despite the small experimental scale, an increase in power output by magnetically induced ionization was successfully achieved with good reproducibility, when preionization was suitably applied.