Quasi-cw nuclear-pumped laser utilizing atomic transitions in argon

Investigations were made of a high-pressure infrared laser utilizing the 3d–4p transitions in the argon atom at the wavelengths 1.27, 1.69, and 1.79 μm excited in He–Ar and Ne–Ar mixtures by uranium fission fragments. The dependences of the energy, threshold, and spectral characteristics of the laser radiation on the type of buifer gas and on the component ratio of the mixture were determined. A maximum output power of 390 W, with an efficiency of 0.6%, was recorded using an He:Ar = 500:1 mixture at a pressure of 2 atm. The minimum lasing threshold was obtained for a thermal neutron flux density 9 X 10¹³ cm^–2·s^–1 and an Ne:Ar = 500:1 mixture at a pressure of 1 atm.