XeF* (C1/2) radiative lifetime measurement

Abstract

By monitoring the spontaneous emission from electron‐beam‐excited xenon difluoride (XeF₂) plasmas, the radiative lifetime of XeF* [C (1/2)] has been determined. Excited XeF was formed directly through electron‐impact dissociative excitation of XeF₂. The time behavior of the subsequent 351‐nm fluorescence displayed two distinct exponential decay regions. The first was characterized by a pressure‐independent decay constant of 16.5±5 ns, the radiative lifetime of XeF* [C (1/2)]. The time constant of the second region was linearly dependent on XeF₂ pressure, indicating that C‐state XeF molecules are, in the late afterglow, formed by a two‐body collision process exhibiting a large rate constant (∼3×10⁻¹⁰ cm³ sec⁻¹).