High frequency breakdown for argon in partial vacuum

Summary form only given. A problem exists for electronics operating in partial vacuums. The breakdown voltage for a gas decreases as the pressure decreases from atmospheric conditions and reaches a minimum. After this minimum breakdown voltage, it starts to increase as pressure further decreases for a given fixed electrode spacing. An increase in operating frequency can also cause a breakdown to occur at lower applied voltage levels1´Icirc1. In this work, the breakdown characteristics for Argon are studied in partial vacuum of 0.1 Torr to 5 Torr. A unipolar pulsed signal at kHz frequencies is applied to parallel plate and point-plane geometries. The frequency is varied from 20 kHz to 100 kHz with a fixed duty cycle of 50%. The I-V characteristics are captured during gaseous breakdown and studied as the frequency is swept over a range of pressures. Voltage and current characteristics are discussed and plasma characteristics are presented.