Photodissociation of XeF2 (Xenon Difluoride) at 193 nm

Interest in the spectroscopy of xenon difluoride XeF2 has been stimulated by the xenon fluoride XeF laser, which operates on the B-X transitions at 351 and 353 nm and the C-A transitions at 483 nm. The vacuum ultraviolet VUV photolysis of XeF2 can be used either to obtain laser action on these transitions or to produce the several electronic states of XeF for kinetic studies. The XeF2 photodissociation laser has been pumped by UV sources, such as discharges initiated by exploding wires, UV radiation emitted by Xe2 excited by an electron beam, and sliding surface discharges. Modeling the performance of the XeF laser, requires rate coefficients for the kinetic processes that produce and remove the vibronic levels of the upper electronic state. The absorption coefficient of XeF2 has been measured at 193, 206, and 253 nm. The present measurements of XeF2 absorption of 193 and 253 nm appear to resolve the discrepancy in those absorption measurements. Adjusting the data of the two previous investigations to match our values at these two wavelengths brings the two sets of measured absorption coefficients into agreement in the overlapping wavelength interval, 203 to 210 nm. We determined experimentally that one molecule of XeF2 is dissociated for each photon absorbed at 193 nm. Keywords Excimer lasers.