Study of the XeCl laser pumped by a high-intensity electron beam

Abstract

We present the results of a detailed experimental study of the XeCl laser pumped by a high-intensity electron beam. The laser system was optimized as an oscillator for mixtures of Xe and HCl with Ne, Ar, and Kr diluents. The peak intrinsic efficiency (laser energy out/electron-beam energy deposited) was near 4.5 percent for each of these diluents. Small-signal gain and background absorption were measured as a function of electron-beam deposition rate from 0.4 to 6 MW/ cm3. The ratio of small-signal gain to absorption was found to be constant over this range with a value of ∼5. Measurements of absorption in the presence of a large photon flux indicated that there was no appreciable saturable contribution to the absorption. Measurements of fluorescence from the B and C states indicate that collisional mixing between these states is very rapid. The formation efficiencies of the B and C states are estimated to be 0.15 and 0.05, respectively. A vibrational relaxation rate of between 1 and 1.5 \times 10^{-10} cm3. s-1was determined. The effect of this finite relaxation rate is to reduce the energy available to the stimulated process by a factor of 0.67-0.75. Estimates of the XeCl* deactivation rates by HCl and electrons were also obtained. A value of 1.7 \times 10^{-9} cm3. s-1was obtained for quenching by HCl, and a value of \sim 1 \times 10^{-7} cm3. s-1was estimated for electron deactivation.