THERMODYNAMIC RESTRICTIONS FOR CHEMICAL-LASER EFFICIENCY

A thermodynamic approach to the problem of the maximum efficiency for a chemical laser is developed. Assuming the laser radiation entropy to be negligibly small in comparison with the entropy of the chemically reacting compounds, the thermodynamic limitations for the laser effici ency are obtained. A number of kinds of chemical reactions, each one b eing a source of laser pumping, are explored. It is shown that the mos t significant restrictions appear for reactions of recombination type reducing the number of particles in the laser mixture. Photorecombinat ion lasers are investigated in detail. The maximum efficiency for thos e lasers is computed over a wide range of proposed parameters of the i nitial mixture.