Role of nonlocal ionization in formation of the short glow discharge

An analytical model for estimating basic characteristics of short (without a positive column) glow discharges is suggested that allows for electron generation both in the cathode sheath and by nonlocal ionization in the plasma negative glow. The model is based on a previously developed approach according to which the discharge gap is divided into space-charge layers and a quasi-neutral plasma. The plasma region includes part of the negative glow, Faraday dark space, and positive column (if it exists). Simple expressions for basic characteristics of the glow discharge (I-V characteristic, cathode sheath thickness, position of the point of electric field reversal, etc.) are derived, and plasma concentration distributions are presented. The results obtained in terms of our model are in good agreement with experimental data, while local approximations based on the classical Engel-Steenbeck model diverge considerably from the experiment.