O2(1Δ) production in flowing He/O2 plasmas.: II.: Two-dimensional modeling -: art. no. 073304

In conventional chemical oxygen-iodine lasers (COIL) the 1.315 mu m transition in atomic iodine is pumped by a sequence of reactions of I-2 and I with O-2((1)Delta) which is generated using liquid chemistry. Ongoing studies are investigating means to produce the O-2((1)Delta) precursor with an electric discharge (eCOIL) to enable a totally gas phase system. Due to the thermodynamic and power loading requirements, the plasma in eCOIL systems is sustained in a flow of a rare-gas diluent and the O-2. In previous investigations, the scaling of production of O-2((1)Delta) was investigated using global-kinetics and one-dimensional (1D) models. It was found that the production of O-2((1)Delta) scaled linearly with energy deposition for moderate loadings (a few eV/O-2 molecule). In this paper, these previous investigations are extended to two-dimensions using a plasma hydrodynamics model. The goal of this investigation is to determine if multidimensional considerations affect energy scalings for production of O-2((1)Delta). We found that O-2((1)Delta) production generally does scale linearly with energy loading, however, the saturation of O-2((1)Delta) production occurs at lower-energy loadings than predicted with global and 1D models. This trend is a result of the more accurately depicted and more localized energy deposition afforded by the two-dimensional model, and emphasizes the need for volumetrically uniform power deposition to optimize O-2((1)Delta) production. (c) 2005 American Institute of Physics.