Glow and Townsend dielectric barrier discharge in various atmosphere

The electrical characteristics of homogeneous dielectric barrier discharges in helium, argon and nitrogen are presented and discussed. From the evolution of the discharge current as a function of the voltage applied to the gas it is shown that (i) in helium and argon, during the current increase, the discharge transits from a non-self-sustained discharge to a Townsend discharge and then a subnormal glow discharge (atmospheric pressure glow discharge) (ii) in nitrogen the ionization level is too low to induce a localization of the electrical field and the glow regime cannot be achieved. The discharge is a Townsend discharge (atmospheric pressure Townsend discharge). The characteristics of this specific discharge are described including the time variation of the density of electron, ion, metastable state and electrical field.