TA4 - Characteristics of a high-energy hydrogen fluoride (HF) laser initiated by an intense electron beam

The characteristics of a high-energy hydrogen fluoride (HF) laser and the effects of optical elements on beam quality and on energy extraction are described. The HF laser is initiated by injecting a 2-MeV electron beam into a mixture of SF
6
and C
2
H
6
. With 300-torr SF
6
and 30-torr C
2
H
6
, the radiated energy with a flat mirror on one end of the laser cell is ≈80 percent of the two-way energy when no mirrors are used. The effect of a confocal unstable resonator in providing collimation of the laser beam was studied. The maximum laser energy measured was 380 J in a 23-ns full width at half maximum (FWHM) pulse. The maximum electrical efficiency measured was 14 percent, which is about 60 percent of the maximum theoretical value.