Investigation of the conditions for efficient initiation of HF chemical lasers by a relativistic electron beam

An investigation was made of the feasibility of achieving a high specific output energy and a high electrical efficiency in an H₂2 chemical laser excited by a relativistic electron beam. Using an H₂:F₂:O₂:He = 6:15:1.2:50 mixture at a pressure of 1.3 atm, a specific output energy of 100 J/liter was achieved with an efficiency of ~900% with respect to the energy deposited in the active volume of the laser and a chemical efficiency of ~4%. The degree of initiation and the efficiency were estimated using the experimentally measured electron beam energy absorbed by the active volume of the laser. A high efficiency of utilization of the electron beam energy, ~200%, was obtained. It was found that the H(F)+O₂+M→H(F)O₂+M three-body recombination process was very undesirable in active mixtures at pressures of ~1 atm. The rate constants of this reaction for M = He, Xe, and SF₆ were determined experimentally.