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 $\text{≲ 1.5\hspace{0.17em}}{\mathrm{A/cm}}^2$ . 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%.