Research on miniaturized high-voltage pseudo-spark switch

Background Pseudo-spark switches are key components in pulsed power systems, offering high withstand voltage, high current rise rate, and low electrode erosion. However, conventional pseudo-spark switches often suffer from large volume and heavy weight due to their discharge cavity design, which limits their application in compact and portable pulsed power devices.

Purpose This study aims to design a miniaturized high-voltage pseudo-spark switch that meets the demands of compact pulsed power systems. The goal is to significantly reduce the switch size while maintaining high voltage and high current capabilities, and to enable customizable voltage ratings through a modular voltage division design.

Methods A miniaturized pseudo-spark switch with dimensions of Ø36 mm × 55 mm was developed. A needle-type trigger structure made of tungsten was adopted to generate initial plasma, replacing conventional large-area dielectric surface flashover triggers. A room-temperature hydrogen storage material in ring form was integrated into the trigger structure to eliminate the need for external heating and reduce volume. The hollow cathode was designed with an aperture of 2.5 mm and an inner cavity of 15 mm in diameter and 5 mm in height, achieving an effective surface area of 2.3 cm². An experimental platform was built to test the self-breakdown voltage, conduction performance, and triggering characteristics of the switch.

Results Experimental results show that the switch achieves an operating voltage of 35 kV, a pulse current of 42.8 kA, a trigger delay time of 93 ns, and a jitter of 3 ns. The switch can operate repetitively at 10 Hz for 50 pulses per burst and over 20,000 bursts. The relationship between forward anode voltage and peak anode current is linear under fixed discharge circuit parameters. Compared with conventional pseudo-spark switches and other devices such as thyratrons and triggered tubes, the proposed switch offers significantly reduced size and competitive electrical performance.

Conclusions The developed miniaturized high-voltage pseudo-spark switch successfully reduces device volume while maintaining high voltage, high current, and low jitter. It provides a promising switching solution for portable pulsed power systems. Future work may focus on improving the hydrogen storage dynamics for higher repetition rates and longer burst durations.