Pressure and Discharge-Voltage Dependence of Self-Sustaining Pulses in Air-Glow Discharge

The details of formation of micro discharges in air-glow discharge plasma are experimentally studied. The number of micro discharges formed per second is strongly related to both pressure and discharge voltage. This number tends to show reflections of the Patchen curve as far as its pressure dependence is concerned. The discharge-voltage dependence indicates that the transition from normal to abnormal glow discharge is not a sudden one, but has its roots during the normal glow stage and is initiated by the micro discharges which can be regarded as the early stage of abnormal glow.