Sealed-off pseudospark switches for pulsed power

There has been a considerable progress in understanding the physics and technology of high power pseudospark switches, which allows their implementation in pulsed power applications. These switches have very wide dynamic range of breakdown voltage operation: from 1% to 99%. Single-gap systems still have the disadvantage of small hold-off voltage, which is lower than 25 kV and which requires the construction of two-stage systems. In this way, a more reliable hold-off voltage as high as 30 kV would be achieved. Based upon a better understanding of fundamental discharge processes, it is possible to suppress the quenching phenomenon. This might prove helpful in some pulsed power applications. Semiconductor electrode materials are the best choice for devices with considerably reduced electrode erosion and prevention from statistically distributed drop of impedance. The feasibility of a durable composite of semiconductor and metallic bath electrode will facilitate tremendously the construction of sealed-off pseudospark switches for pulsed power applications, especially to replace ignitron and spark gaps. Up to now, the tested prototypes operate with hold-off voltages up to 20 kV, peak currents up to 150 kA and pulse length up to 20 /spl mu/s. Tests with longer pulse length are planned in order to extend the commercial applicability of these devices.