Hollow anode discharge represents a new type of discharge which is realized in a diode consisting of a concave cathode and a special type of hollow anode whose inner surface only is conductive. The concave cathode focuses electrons toward the hollow anode, increasing the density of high energy electrons and the efficiency of excitation and ionization in the hollow anode. The optical spectrum, which consists of ion lines only, indicates that in the hollow anode a highly ionized plasma is obtained. The spectrum does not consist of cathode (or anode) material lines.

Spectroscopy of hollow anode discharge.

High-power stimulated radiation was obtained in three fluorides of rare gases by exciting a high pressure mixture of He+R+SF6 (R is argon, krypton, xenon) by a pulse electric discharge (mixture pressure ranged from 1 to 10 atm). The ArF laser superradiance spectrum of about 15 A total width with the centre at λ=1932 A is given. The ArF laser power wasP≈104 W. The KrF laser generated 2 ns pulses of about 2.5 MW power at λ=2486 A with a linewidth Δλ≈10 A. This laser efficiency in relation to the stored energy of an accumulator is about 0.2%. In the XeF laserP=200 to 300 kW, τ=3 to 3.5 ns, λ=3511, 3531 A. High density of superradiance power is observed. The prospects of increase of mean power of excimer lasers are discussed.

Superradiative rare gas halide lasers excited by electric discharge

HIGH-PRESSURE GAS LASERS ON Ar I, Xe I, AND Kr I TRANSITIONS

Intense laser pulses with peak powers in excess of 0.5 MW have been obtained routinely at 4278 A [(0, 1) band of B 2Σ+u–X 2Σ+g system] from a unique spark‐preionized large‐volume TE laser. High‐pressure operation of this laser with N2 (3371 A), Ar (0.912, 0.962, 1.270, 1.791 μ), and Xe (1.723 μ) is also discussed.

High‐power N2+ laser pumped by charge transfer in a high‐pressure pulsed glow discharge

A preionized transverse electric‐discharge‐pumped N+2 charge‐transfer laser oscillating on the (B2Σ+u−X2Σ+g) transition of N+2 is reported. Peak power of 180 kW in a 8‐nsec FWHM laser pulse has been obtained with a 0.1% mixture of N2 in helium at a total pressure of 3 atm. The most intense laser oscillation occurs on the (0,1) vibrational transition at 427.8 nm.

V.N. Starinsky

Papers

The N+2 laser