Electrical Conductivity of Thermally Ionized Air Produced in a Shock Tube

Abstract

The electrical conductivity of shock-heated air at equilibrium temperature from 3500°K to 6200°K, and at densities of the order of 0.01 NTP, has been measured, using the shock wave-magnetic field interaction technique reported by Lin, Resler, and Kantrowitz. The experimental results indicated that the ionization process builds up quickly behind the shock front, and that the measured conductivity agrees quite well with calculated values based on the equilibrium degree of ionization, the electron diffusion cross sections for the molecular species available in the literature, and on a theoretical estimate of the scattering cross sections for oxygen and nitrogen atoms by Hammerling, Shine, and Kivel based on the Hartree potential with appropriate exchange and polarization terms.