Laser-induced fluorescence of gaseous UF6 in the A–X̃ band

Abstract

The A–X̃ band of gaseous UF₆ has been studied using the laser‐induced fluorescence technique. Excitation and fluorescence spectra are presented for various pressures of UH₆ at room temperature. The fluorescence spectra show little change over the pressure range 0.2–20 torr, with a peak wavelength at 421 nm. In contrast, the peak wavelength of the excitation spectra shows a noticeable shift from 391 to 385 nm when the UF₆ pressure is increased from 2 to 20 torr. A Stern–Volmer plot of UF₆ self‐quenching data shows a pronounced nonlinear behavior over this same pressure region. From an analysis of the laser‐induced fluorescence spectra, we develop a simple kinetic model for UF₆ excited‐ state dynamics. A standard kinetic treatment of this scheme yields a prediction for the dependence of the fluorescence decay lifetime on total pressure that is in good agreement with experimental results.