Operation of a 15-atm electron-beam-controlled CO2 laser

We describe the operation of a 15-atm electron-beam-controlled CO2 laser. Stable glow discharges have been sustained in the high-pressure He:CO2:N2 mixtures for 0.5 μsec using an electron-beam current of ≲ 1.5 A/cm2. A small-signal gain ∼ 0.052 cm−1 has been measured in a 70%(He):25%(CO2):5%(N2) mixture for an energy input to the gas ∼ 115 J/l atm. We have obtained a laser output energy of 1.2 J from a volume of 22 cm3 for an over-all efficiency of 2.5%.