A repulsive-field technique for obtaining the mobility-spectra of the ion species created in a corona discharge

A repulsive-field technique has been developed for obtaining the mobility spectra of a distribution of ions present in a dynamic gas environment. It has been applied to an investigation of the negative-ion spectra of corona discharges in ambient air, oxygen, and related oxygen-nitrogen mixtures. Spectra are presented as a function of the inverse mobility (1/K); the present resolution of the technique - (1/K) is ∼ 0.1 V sec/cm2. Future applications of the technique are discussed.