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).