Intense electron-beam initiation of a high-energy hydrogen fluoride (HF) laser

A superradiant hydrogen fluoride (HF) laser is described in which an intense electron beam, propagating in a SF6and C2H6mixture, is used to initiate chemical reactions that produce vibrationally excited HF molecules. The variation of laser energy as a function of SF6pressure for fixed composition and as a function of composition at a fixed SF6pressure has been investigated. These experimental parametric curves are discussed in terms of the relevant physics. The maximum laser energy of 228 J in a 55- ns full-width-at-half-maximum (FWHM) pulse was obtained with a mixture of400-torr SF6and 40-torr C2H6. Measured efficiency for converting deposited beam energy to laser energy propagating in the forward direction was as large as 8 percent.