Gennadii A. Mesyats

Wide-aperture CO2 lasers pumped by electron-beam-controlled discharge

Three powerful wide-aperture CO2 lasers with the wavelength λ = 1.06 μm (a laser pumped by electron-beam-controlled discharge, a high-pressure continuously tunable laser, and a repetitively pulsed laser) are created and studied. A method for the volume discharge generation proposed at the High-Current Electronics Institute is used for the development of the lasers.

Effective XeCl-laser performance conditions with combined pumping

Abstract Results are presented of experimental researches of a XeCl-laser with discharge stability by a short electron beam. The maximum radiation energies are shown to be realized in a discharge with electron multiplication in the presence of low inductances of the discharge circuit and when achieving the threshold of generation from energy deposited into gas by an electron beam. Specific radiation energy of 2.5 J/I and efficiency ∼3% are obtained.

High-power wide-aperture electron-beam-pumped lasers on dense gases

Schemes of high-power electron-beam-pumped pulsed lasers on dense gases and the experimental results on the lasing on XeCl*, KrF*, and HF molecules are presented. The energy input and the kinetic processes in the active medium of the electron-beam-excited XeCl laser are calculated. Radiation pulse energies of 1900, 200, and 90 J are obtained at wavelengths of 308 nm, 2.8 μm, and 249 nm, respectively.

Petawatt Excimer Laser Project at Lebedev Physical Institute

The Project of petawatt excimer laser was started at Lebedev Physical Institute (LPI) in collaboration with High‐Current Electronics Institute (HCEI). It utilizes Ti:Sa front‐end to generate 1mJ, 50 fs pulses, frequency conversion into 2ω or 3ω and direct amplification of short pulses in a chain of excimer amplifiers with e‐beam or photochemical pumping. Multi‐terawatt output in 20‐J, subpicosecond pulses at KrF (λ = 248 nm) is projected being combined with 4‐kJ, nanosecond pulses. Petawatt femtosecond pulses at Kr2F (400 nm) might be expected, if transient absorption could be reduced in e‐beam‐pumped gain medium. For photochemically‐pumped XeF amplifiers (480 nm) multi‐petawatt level is attainable with a high temporal contrast.

Low-threshold gas lasers pumped by plasma-cathode accelerators

The lasing on the electronic transitions of xenon and neon is studied. It is demonstrated that plasma-cathode accelerators serve as effective sources for the pumping of low-threshold lasers (W < 100 W/cm3). The laser energy in xenon at the wavelength λ = 1.73 μm is 5 J at an efficiency of 2%, and the laser energy in neon at the wavelengths λ = 585.3 nm is 0.5 J at an efficiency of 0.3%. The repetitively pulsed mode of the xenon and neon lasers carried out at a repetition rate of 50 Hz. The radiation energy of a wide-aperture laser with an active volume of 600 l is 100 (0) J for a wavelength of 1.73 (2.03) μm at an efficiency of 2% (1%).

38-GHz relativistic backward-wave tube based on a modulator with an inductive energy accumulator and a semiconductor current interrupter

The results of an investigation of a 38-GHz relativistic backward-wave tube with an output power up to 40 MW are presented. An electron-beam injector based on a 5-ns high-current pulsed periodic modulator with an inductive energy accumulator and a semiconductor current interrupter is used for the first time in experiments.

POSSIBLE UTILIZATION OF A VAPOR, FORMED BY THE ACTION OF A HIGH-POWER ELECTRON BEAM ON A TARGET, AS AN ACTIVE MEDIUM FOR STIMULATED EMISSION OF LIGHT

A discussion is given of a vaporization of a metal by the action of a high-power electron beam formed as a result of pulsed vacuum breakdown. The optical parameters of such a beam (108 W/cm2 for electrons of 100–200 keV energy) make it possible to supply an energy sufficient for the sublimation of each atom. When an energy of 450 J is supplied from a storage capacitor to a vacuum diode, it is possible to attain a metal vapor concentration of at least 1017 cm–3 in a volume of 20 cm3.