Multichannel switching in a multigap gas switch at atmospheric pressure

Abstract

The multichannel switching mode of a controlled multigap switch is studied. The switch is designed for capacitive energy storage, with a charging voltage of up to 100 kV and an energy output time of about 100 ns. The interval between the high-voltage and low-voltage electrodes of this switch is divided into seven series-connected gaps using ball electrodes, and six parallel rows of these ball electrodes allow for multichannel switching. An optical system based on collimators and photodiodes was used to determine the number of channels in the switch gaps. Statistics on the number of channels were collected and the probability of ignition of parallel spark channels was calculated for each of the switch gaps under different operating conditions. We show that both the electrical isolation between the channels and the rate of rise of the triggering pulse significantly affect the number of parallel ignited channels and their distribution over consecutive gaps. At a high triggering voltage pulse rise rate ($\ensuremath{\sim}800\text{ }\text{ }\mathrm{kV}/\ensuremath{\mu}\mathrm{s}$), a larger number of spark channels are ignited in the switch with electrical isolation between the channels and the characteristics of this switch are better. At a low triggering voltage pulse rise rate (less than $250\text{ }\text{ }\mathrm{kV}\text{ }\ensuremath{\mu}\mathrm{s}$), better characteristics are realized in the switch without electrical isolation between the channels.