Laser-triggered gas switch with subnanosecond jitter and breakdown delay tunable over ∼0.1–10 ns governed by the spark gap ignition angle

Abstract

We created a practical air-filled switch triggered by a ∼109 W picosecond laser beam with a slightly variable breakdown delay and low jitter. The switch relies on the spark gap with a coaxial geometry, which is ignited by a focused laser beam directed at a certain angle to the gap axis. The switch is integrated with a high-voltage cable generator operating at a constant negative voltage of up to 50 kV. We demonstrate that, by just varying the ignition angle of the spark gap, one can achieve variable breakdown delay tunable within ∼0.1–10 ns with ≲1 ns jitter. Empirical dependences of switching characteristics of the developed device on the ignition angle are obtained. We demonstrate that, combined with variation of the ignition beam energy and charging voltage, variation of the spark gap ignition angle provides superior control over the gap switching characteristics without complicating the switch design. The proposed approach to driving the switching characteristics appears highly promising for designing compact laser-triggered gas switches with variable temporal characteristics and achieving precise synchronization between high-voltage and measuring equipment.