The Dynamics and Characteristics of the Pulsed Discharge in the Active Medium of a Pulsed Chemical Oxygen-Iodine Laser

Abstract

In this article, a one-dimensional self-consistent hybrid model of fluid and kinetics is developed to simulate the pulsed discharge occurring in the active medium with a composition CF3I–O2–O2(a1 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\bigtriangleup$ </tex-math></inline-formula> g)–He in a pulsed chemical oxygen-iodine laser (COIL). The iodine atom formation mechanism, the energy exchange between singlet delta oxygen and iodine atom, and the behaviors of various discharge products during the discharge and postdischarge are studied in detail. The dependences of the iodine atom density and energy cost of an iodine atom on the partial pressure ratio of the gas mixture are analyzed and discussed. It is shown that the main channel of iodine atom formation is the electron impact dissociation of CF3I rather than the ionization process. Chemical reaction processes have a small contribution to I atom production, especially the reaction processes involving oxygen. Keeping total pressure and oxygen partial pressure unchanged, there exists an optimum ratio of CF3I:He, at which the highest iodine atom density and the lowest energy cost are achieved. Under simulation conditions, I atom concentration decreases with increasing total operation pressure and oxygen pressure. At constant total pressure and oxygen pressure, when the content of singlet oxygen is lower than 40% of total oxygen pressure, the population inversion cannot be formed.