Gas laser excitation by an electron beam formed at open discharge

Abstract

The method of formation of powerful electron beams (EBs) with nanosecond duration has been described (electron energyu≈10 to 20 keV and beam currentl _EB>1 kA) in the medium pressure gas which is simultaneously the laser active medium. The value ofl _EB=7 kA has been achieved atU=22 kV, τ=20 ns andp _Ne=300 Pa in a coaxial cell 330 mm long and 99 mm in diameter. The 3 kA current from the cathode with 60 cm² square in the shape of a segment of a sphere 140 mm in diameter has been achieved atU=23 kV, τ=15 ns andp _Ne=300 Pa. With the help of a magnetic field this beam has been transported to a distance of up to 100 cm.

Applications of the beams for pumping various lasers were broadened. Lasing in He + Cd⁺ mixtures at the optimal He pressure of 10 to 12 kPa and in the triple mixture He-Cd-Kr has been obtained. Using the method of doubled excitation pulses it has been shown that EB pumping provides preservation of the lasing pulse parameters in the Eu atom laser in comparison with glowing discharge, the sequential frequency being an order of magnitude greater. Lasing at a significantly greater ion concentration than in gas discharge has been obtained in the ion laser on the self-terminating transition of Ca⁺,λ=866 nm. Quasicontinuous lasing has been realized in the mixture He + Sr + Kr in the plasma laser on Sr⁺,λ=430.6 nm.