Photoionization of nitrogen and oxygen mixtures by radiation from a gas discharge

A study is made of the photoionization of N2-O2 mixtures by radiation from an electric discharge burning in the same gas. The molecular bands of nitrogen in the vacuum ultraviolet are shown to be the source of the ionizing photons. It is established that photoelectrons arise in response to the direct ionization of oxygen molecules, which also determine the absorption of ionizing radiation. An analytic expression for calculating the rate of photoionization is obtained that agrees satisfactorily with the experimental data.