Ionization instability and stable region in potassium seeded argon gas plasma MHD generation

In nonequilibrium MHD generation with alkali metal seeded noble gas plasma, stable regions free from ionization instability are investigated in terms of seed fraction magnetic field strength and current density by using linear perturbation theory with allowance for the ionization of noble gas atoms. Regardless of fluctuations, a Faraday-type MHD generator with finely segmented electrodes operating with a seed fraction of 10-3 gives, in general, higher power density than a smaller seed fraction of 10-5, and the power density can attain the target power density 50 MW/m3 even at a low gas temperature of 1500K and a high pressure of 20 atm.