Studies of a high-energy HF laser using an electron-beam-excited mixture of high-pressure F2 and H2

Chain-reaction lasing of mixtures of F2, O2, and H2 at pressure ratios of 1/0.3/0.25 with F2 pressures up to 800 Torr was initiated with an electron beam, and a parametric study of laser emission was performed. In one series of studies the F2 and O2 pressures were held constant while the hydrogen pressure was varied up to stoichiometric. Under some conditions, SF6 or He was added to the above mixtures. A maximum laser energy of 4.2 kJ was measured at the higher pressures. Chemical and electrical efficiencies of up to 11.4% and 180%, respectively, were obtained. Each of these efficiencies has been found to be dependent upon the gas pressure and composition. The measured laser energy was found to be proportional to the measured electron-beam energy deposited in the gas. Addition of an unstable resonator provided a beam with a 4-mrad divergence.