Investigation of an Ar–N2 laser pumped by an intense proton beam

Investigations were made of the dependences of the output energy, efficiency, and duration of lasing on the specific energy (maximum value 1 J/cm³) supplied to a gas. Lasing was observed as a result of four transitions in the 2⁺ system of nitrogen, for which the threshold values of the specific input energy were determined. An increase in the specific input energy increased the optimal concentration of nitrogen in the mixture. In the case of sufficiently intense pumping the duration of lasing exceeded the lifetime of the upper active level, indicating the restrictions imposed by self-termination of the transitions were lifted. The maximum efficiency in a low-Q resonator was 0.6%, the output radiation energy was 0.3 J, and the specific output energy was 5 J/liter.