COMPARISON OF MODEL PREDICTIONS WITH DETAILED SPECIES KINETIC MEASUREMENTS OF XECL LASER MIXTURES

Detailed measurements of the time-dependent electron density, xenon excited-state densities, and total HCl depletion have been recently made in electron-beam- (e-beam-) pumped XeCl. This paper presents the results of extensive computer modeling of these experiments and detailed comparisons with the measured results. The model used includes updated HCl reaction cross sections and an enlarged xenon excited-state manifold. A reduced Boltzmann equation is used to calculate the high-energy electron-energy distribution function, and the low-energy distribution function assumes a quasi-Maxwellian distribution. These changes are upgrades to prior models. The model accurately predicts the total HCl depletion, the time-dependent electron density for initial HCl concentrations ≥0.16% (4.8 Torr), and the time-dependent xenon excited-state densities for lean (≅0.04%) initial HCl concentration cases. The model tends to underpredict the rate of electron-density growth after the electron density begins to run away. Since depletion of HCl is a key factor in understanding the kinetics data, possible mechanisms that can contribute to this process are also discussed.