High efficiency multikilojoule HF chemical lasers using an electron beam initiated low-pressure mixture of H2/F2/NF3 or H2/F2/SF6

High electrical and high chemical efficiencies were simultaneously achieved for the multikilojoule HF chemical laser using a Lambda-type (inclined type) electron beam initiation scheme. The optimum addition of NF3 or SF6 fluorine donor could increase both efficiencies and could reduce the total pressure of the laser gas mixture. The laser output obtained from the low-pressure mixture of H2/F2/O2/NF3=30/208/62.5/70 (Torr) was 4.5 kJ in a 50-ns FWHM pulse width with an electrical laser efficiency of 226% and a chemical efficiency of 18.5%.