Influence of water vapour impurities on the atomic Xe laser

Abstract

The influence of water vapour impurities on the output power of the 1.73 µm 5d[3/2]1-6p[5/2]2 Xe I laser has been studied. The laser gas was a mixture of 99.5% Ar and 0.5% Xe with a total pressure of 500 mbar and was pumped by 50 µs long 100 MeV 32S9+ heavy ion beam pulses. The gas remained essentially at room temperature during the pumping pulses. A significant reduction of laser power was observed when water vapour at a concentration of more than 1014 cm-3 was added. A simple model assuming electron attachment and collisional quenching by water vapour as the dominant causes for reduced laser intensity was used to fit the experimental data. We obtained a rate constant for quenching the upper laser level (KH2OQ) of 4 × 10-9 cm3 s-1, and a ratio of the rate constant of electron attachment to water vapour to total recombination rate of 6 × 10-16 cm3.