Electric field reversal in near-cathode region of glow discharge in helium

Longitudinal distributions of plasma parameters in a short (free of positive column) glow discharge in helium show evidence for the formation of a potential well for thermal electrons and the reversal of electric field in plasma of negative glow and Faraday dark space. Depending on the reduced discharge length pL, one or two points of field reversal can appear, which determines the sign of the anode fall.