Laser-Triggered Solid Dielectric Switching

A Q-switched ruby laser was used to initiate breakdown in solid dielectric switches with a jitter of less than 3 ns. "Lexan" polycarbonate in thickness from 40 to 80 mils withstood applied voltage pulses (less than 1 ¿s duration) of up to 400 kV. Laser pulse energy of less than 1 joule was sufficient to initiate breakdown in the solid dielectric. A focusing lens and the switch container were immersed in a grading solution of copper sulfate and water. Command triggering down to 50% of the dielectric\´s self break voltage was demonstrated. A test system employing a miniature Marx generator, and a high energy system switching 150 kA at 400 kV to form precisely timed relativistic electron beams, are described.