I2 Dissociation Mechanisms In the Chemical Oxygen-Iodine Laser Revisited Using Three- And One- Dimensional Computational Fluid Dynamics Modeling

Abstract

The recently suggested mechanism of I 2 dissociation in the chemical oxygen-iodine laser (COIL) [Waichman et al., J. Chem. Phys. 133, 084301 (2010)] is based on the assumption that the vibrational population of O 2 (a) produced in the chemical generator is high enough to play an essential role in the dissociation. This mechanism is revisited following the recent experiments of Zagidullin [Quantum Electronics 40, 794 (2010)] where the observed low population of O 2 (b, v = 1) led to conclude that the vibrational population of O 2 (a) at the outlet of the generator is close to thermal equilibrium value. We show that the dissociation mechanism can reproduce the experimentally observed parameters in the laser only if most of the energy released in the processes of O 2 (a) energy pooling and O 2 (b) quenching by H 2 O ends up as vibrational energy of the products, O 2 ( X,a,b). We discuss possible reasons for the differences in the suggested vibrational population and explain how these differences can be reconciled. In addition, a simple one-dimensional (1D) computational fluid dynamics (CFD) model of the chemical oxygen iodine laser (COIL) with supersonic mixing is compared with three-dimensional (3D) CFD models and with experimental measurements of the COIL parameters. Dependence of the gain, iodine dissociation fraction and temperature at the resonator optical axis and of the output lasing power on the iodine flow rate predicted by the 1D model is in good agreement with that found using 3D models and experimental results.