Flashlamp design has been developed for the pumping system of the large-aperture optical amplifier used at "Luch" laser facility. Both the modernization of the mechanical units has been carried out and the proper xenon pressure in flashlamp tubes has been chosen on the results obtained from pilot flashlamps reliability tests. For 300 us pulses of discharge current at the energy loading factor of 0.25 the flashlamp lifetime exceeds 10,000 pulses.

A description is given of the apparatus and calculation method used in experimental and theoretical determination of the characteristics of an electron-beam-controlled CO laser operating exclusively on the basis of the transitions corresponding to the first vibrational overtone. The results of the experimental and theoretical studies are analysed and compared. The adopted model gives results in good agreement with the experimental data for CO—N2 mixtures. A study is reported of the influence of the optical cavity selectivity on the lasing characteristics. Calculations demonstrate that a change from a narrow-band cavity used in our experiments to a broad-band nonselective cavity should improve the energy characteristics of the laser by about an order of magnitude.

CO overtone laser pulses with energy up to 4.4 J and efficiency up to 1% with completely suppressed lasing in the fundamental band were obtained from mixtures of CO:N2 excited by an e-beam sustained discharge with a duration of 1.5 microsecond(s) . A comprehensive model of this laser was formulated. The results of numerical simulations satisfactorily correlate with experiments. The conditions for obtaining efficiency as high as 20% are predicted.

This communication is the first report of the simultaneous measurement and quantitative theoretical investigation of gains in vibration-rotation transitions of CO and CO/sub 2/ molecules with pumping by an externally sustained discharge. The experiments were carried out on an uncooled atmospheric-pressure electroionization laser. An analysis of the experimental conditions described above and the characteristic times for the establishment of quasi-equilibrium vibrational distribution functions in the modes of CO/sub 2/ showed that it is sufficient to use the harmonic oscillator model to describe CO/sub 2/ molecules. Measurements and calculations of the lasing characteristics were carried out. It was discovered that an addition of carbon dioxide can lower the efficiency to lasing in a CO transition by several fold, while the reverse influence is insignificant.

Experimental and theoretical investigations were made of the characteristics of an uncooled electron-beam-controlled atmospheric-pressure laser utilizing simultaneously vibrational–rotational transitions in the CO and CO2 molecules. A theoretical model was developed on the basis of a self-consistent solution of the equations of vibrational kinetics and the Boltzmann equation for the electron energy distribution function. A good agreement between the experimental and calculated results was obtained. An investigation was made of the problem of control of the emission spectrum. It was found theoretically that the overall efficiency could reach ~20% (in the case of approximately the same efficiencies in the spectral ranges 5.5 and 10.6 µ) if a laser of this type were cooled to 200 K.

The first report is given of attainment of isotopically selective dissociation of carbonyl chloride COCl2 molecules by radiation from a pulsed tunable uncooled electron-beam-controlled CO laser. Carbonyl chloride was labeled with 13C and 18O and the isotopic ratio was 12C16OCl2:13C16OCl2:12C18OCl2 = 1:1:0.1, which made it possible to observe simultaneously the selectivity in respect of carbon and oxygen in the product (CO). The dissociation was produced by laser pulses of 0.5–1J energy (energy density ∼ 5 J/cm2) and of ∼ 5μsec duration at half-intensity. The dependences of the selectivity a and of the dissociation yield on the pressure of the substance was studied in the course of irradiation of COCl2 at the frequency corresponding to the P10(22) ( = 1822.0 cm−1 ) transition in the CO laser. The selectivity in respect of the carbon 12C and oxygen 16O was the same, and it fell on increase in the pressure p of COCl2. The maximum value of ≈4 was obtained at p = 0.5 Torr.

Simultaneous lasing of CO and CO2 molecules was observed in a pulsed electron-beam-controlled atmospheric-pressure laser operating at room temperature. A strong influence of the addition of CO2 molecules on the energy characteristics of CO radiation was observed. A study was made of the energy characteristics of CO/CO2 lasing as a function of the composition of the mixture.