Energy and gasdynamic characteristics of a supersonic cw chemical HF laser with a radial-expansion nozzle array

Abstract

An experimental investigation was made of the energy and gasdynamic characteristics of a supersonic cw chemical HF laser with a radial-expansion nozzle array of 35 cm × 10 cm dimensions. A nozzle—sonic injector configuration was used for reactant mixing. A specific output energy of 254 J g-1 and an absolute laser radiation power of 33.5 kW were reached. The distributions of the Mach number, of the static pressure, and of the total pressure behind a plane shock wave in the flowing active medium were measured in wide ranges of the pressure in an atomic-fluorine generator and of secondary fuel (hydrogen) flow rates. The optical quality of the active medium, characterised by the Strehl number St=0.53, was estimated. The advantages and shortcomings of a laser with a proposed nozzle array configuration were identified. Future investigations were outlined.