Macroscopic Conductivity Measurements of Ionized Air

Ionization chamber measurements of bulk ionized air conductivity are complicated by the formation of a diode-like electron depletion layer at the interface of the negatively charged cathode and the ionized gas. Conduction across the electron depletion layer is dominated by ionic conductivity. The production of secondary electrons at the cathode by positive ion bombardment is postulated to explain abnormally large currents across the electron depletion layer at late time in N2 gas. A biased waveguide rf absorption technique has been developed to measure the electron conductivity of ionized gases in the region outside the electron depletion region.