Performance and diagnostic measurements of a supersonic HCl chemical laser

A supersonic purely chemical continuous wave HCl laser is described in which nonequilibrium concentrations of atomic chlorine are generated by the branch-chain reaction of NO with ClO2. The ClO2 is injected into a stream of NO in helium immediately upstream of the throat of a slit nozzle. The reacting gases then expand as a free-jet into a low-pressure region where HI is added to rapidly form vibrationally excited HCl. The maximum HCl multiline output power of 35 W obtained represents a chemical efficiency of approximately 4.5% based on the total exothermicity of the pumping reaction and the limiting flow rate of HI.