REQUIREMENTS FOR SIMULTANEOUS IGNITION OF ALL CHANNELS IN A HIGH-CURRENT RADIAL MULTICHANNEL PSEUDOSPARK SWITCH

In order to reduce erosion of electrodes and consequently achieve a lo ng lifetime for high-power switches, a low-pressure switch, namely the pseudospark switch (PSS), is investigated as an alternative to the co nventional high-power switches. The erosion can be reduced further alo ng with an enhancement of the current and the rate of current rise, if more channels are introduced for the passage of current. An intense e lectron beam is known to be emitted by the hollow cathode during the s tarting phase in a pseudospark discharge. It has been reported that in a multichannel setup each installed channel can ignite only if it get s ionized by its respective beam. The results presented in this paper show how this multichannel operation can be accomplished. These result s are based on a statistical study of a radial multichannel pseudospar k switch and an observation of the discharge course by means of high-s peed photography and show that a glow discharge trigger, with a high g low current (greater than or equal to 1.2 mA) and slowly rising trigge r pulses (greater than or equal to 150 ns), allows a simultaneous igni tion of up to 12 channels.