Modeling of large-aperture CO2-lasers

Abstract

Transverse-discharge excitation of large-aperture CO2 lasers places demanding and unusual constraints on the pulsed power supply. Stable discharges with interelectrode gaps as large as g = 70 cm were achieved using pulsed power supplies that satisfy specific requirements imposed by volume preionization and discharge ignition. The supply must initially apply a quasi-DC or slow-rise voltage to in order to effect preliminary filling of the gap with electrons from an auxiliary discharge, followed by application of a controlled rise voltage to ignite an SSVD. A coupled particle kinetics-equivalent circuit model has been developed to simulate discharge behavior for the various pulsed power configurations. Computational results are compared with experiments involving very-large-aperture, large-volume devices.