Performance of cw HF Chemical Laser with N2 or He Diluent

Recent experimental results on the performance of a continuous HF (or DF) chemical laser are reported. In this device, an arc-heated diluent is mixed in a plenum with SF6 to provide F atoms. The mixture is expanded to form a supersonic jet into which H2 (or D2) is diffused. Population inversion and lasing are due to the reaction H2+F=HF(v)+H; v≤3 and Δ H=−31.7 kcal. Power levels above 1 kW have been obtained in a N2 diluent gas flow, and levels above 1.7 kW have been obtained in a He diluent gas flow. Specific power yields are 43 and 108 kW sec/lb for the N2 and He systems, respectively. The variation of laser power and efficiency with cavity optical axis location and SF6 mass flow are reported for both N2 and He systems. A spectrum of the HF laser operating in a He flow is also presented that gives evidence of v=3 partial inversion.