WA7--Electron-beam-controlled CO2laser amplifiers

The performance of electron-beam-controlled atmospheric-pressure CO
2
laser amplifiers is reported. The amplifiers have an active length of 100 cm and a circular optical aperture of 10 cm
²
. The electrical parameters are 130-kV electron beam energy and 0.15-A/cm
²
cathode current density over 800 cm
²
; 20-kV gas pumping voltage and 7-A/cm
²
gas current density over 800 cm
²
. Referred to the gas, the corresponding values are
E/N = 17
townsends and
j\cdot E = 24
kW/cm
³
. Small signal gain measurements on the
P(20)
line of the 10.4-μ band show gain coefficients up to 0.046 cm
^-1
, depending on the electrical parameters and the gas composition. The operation of the amplifiers as lasers, the results of experiments on pulsed energy extraction, and the uniformity of the small signal gain across the optical aperture are reported.