Stimulated emission due to infrared transitions in chlorine atoms in gaseous mixtures pumped by uranium fission fragments

Abstract

Quasi-cw stimulated emission of ~10 ms pulses at the wavelengths λ =1.59 and 2.45 μm of the chlorine atom was detected when mixtures of He, Ne, and Ar with CCl4, CHCl3, CF2Cl2, and C2F3Cl3 were excited by uranium fission fragments. Stimulated emission of the λ = 2.45 μm line under nuclear pumping conditions at high pressures was observed for the first time. The maximum energy parameters (output radiation power 130 W, efficiency about 0.2%) were achieved for the 1.59 μm line in a mixture of the He : Ne : CCl4 = 25 000 : 25 000 : 1 composition at a pressure of 2 bar. The minimum lasing threshold for this line corresponded to a thermal neutron flux of 2×1013 cm-2 s-1.