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 long lifetime for high-power switches, a low-pressure switch, namely the pseudospark switch (PSS), is investigated as an alternative to the conventional high-power switches. The erosion can be reduced further along with an enhancement of the current and the rate of current rise, if more channels are introduced for the passage of current. An intense electron beam is known to be emitted by the hollow cathode during the starting phase in a pseudospark discharge. It has been reported that in a multichannel setup each installed channel can ignite only if it gets ionized by its respective beam. The results presented in this paper show how this multichannel operation can be accomplished. These results are based on a statistical study of a radial multichannel pseudospark switch and an observation of the discharge course by means of high-speed photography and show that a glow discharge trigger, with a high glow current (/spl ges/1.2 mA) and slowly rising trigger pulses (/spl ges/150 ns), allows a simultaneous ignition of up to 12 channels.<
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