Laser triggering of spark gap switches with less than 100μJ’s of energy

Concepts for future pulsed power systems include designs with high numbers of switches, and in some cases these systems will perform pulse shaping by triggering the switches sequentially in time. Drivers for isentropic compression experiments are being designed with 59 trigger points and hundreds of switches. Future generations of the Z-machine may be based on linear transformer driver technology, requiring ½-million triggered switches. The cost and complexity of triggering these future pulsed power systems with commercially available high voltage trigger generators continues to be prohibitive. Conventional laser triggering in these systems would entail very high initial costs, and maintenance on line-of-sight optics would significantly increase operational costs. Improvements over present day triggering technologies would include electrical isolation using small optical fibers and the ability to trigger large numbers of switches from a single laser. Results from experiments that demonstrate the triggering of a 20kV spark gap switch with less than 100μJ of laser energy through an optical fiber are presented.