METHOD AND DEVICE FOR BUILDING UP INVERSE POPULATION IN CARBON DIOXIDE GAS-DYNAMIC LASER Russian patent published in 2001 - IPC

FIELD: laser engineering. SUBSTANCE: method includes organization of fluid mixing of components in subsonic section of nozzle so that gases were fully mixed up at monomolecular level in vicinity of critical section of nozzle. Parameters of gases being mixed up are chosen and maintained in the course of reactions within desired range so as to organize conditions in which vibratory energy of molecules newly produced as result of chemical reactions in gas is accumulated in gas at low static temperature of gases and imparted to molecules of reacting gases thereby enhancing their reaction rate. Enhanced reaction rate, in its turn, causes further accumulation of vibratory energy in molecules of gas mixture ; in the process, CO is first to burn up and H, to lower extent. As a result, amount of vibratory energy accumulated in gas mixture of proposed laser active medium is much greater and water vapor content is lower at lower static temperature as compared with commonly used gas-dynamic laser. Device implementing proposed method has injector unit of combustion chamber mounted upstream of nozzle unit with its holes admitting cold gas component. Injector unit holes are arranged at optimal distance (L_opt) from critical section of nozzles found from equation L_opt= ud²/D_t, where u is flow speed of gas mixture in subsonic section of nozzle; d is typical size of injector unit; D_t is turbulent diffusion factor. Nozzle blades have central cooling-water passages joined to delivery and drain pipelines; subsonic section is provided with ducts having injector holes to admit cold gas component to main gas flow. Height and elevation of constant critical section of nozzle (h) should meet equation h < τ2chim

(u/ν)³D2m, where τ_chim - is reaction rate of gases; u is gas mixture flow speed in vicinity of critical section of nozzle; ν is kinematic viscosity of gas mixture; D_m is molecular diffusion factor of gases being mixed up. EFFECT: enhanced efficiency of gas-dynamic laser. 8 cl, 4 dwg, 3 ex