Modeling of chemical oxygen-iodine lasers

Abstract

A detailed engineering model for chemical oxygen-iodine laser (COIL) performance modeling and design predictions has been developed. In this model, mixing between the primary oxygen flow and the secondary iodine injectant is treated using a two-stage/three-stream model based on the flow characteristics of the transverse injection mixing scheme. Iodine dissociation, excited state pumping and quenching are treated using the standard Phillips Laboratory COIL kinetics package. Stable resonator optical extraction is described by a rooftop geometric optics model. These models have been incorporated into the two-dimensional advanced cavity code for COIL (AC<SUP>3</SUP>). The validity of the mixing, kinetics, and optics models used in this code has been tested by comparing the predictions of the model with the iodine dissociation, laser small signal gain, and optical power data measured using the high pressure RotoRADICL device. Selected small signal gain and output power measured using the low pressure RotoCOIL were reproduced by the models. Modeling of the high efficiency RADICL data obtained with various nozzle throat heights using this model shows good agreement with power. The good agreement with the data obtained from various devices encompassing a broad range of experimental parameters lends credibility to this model.