Revision of theoretical model of CO laser kinetics was performed including new data on intra- and inter-molecular vibration exchange processes and vibration relaxation in highly excited CO molecules, spontaneous radiation Einstein coefficients for fundumental and overtone bands of CO molecules and cross sections for cascade excitation and de-excitation of CO molecules by electron impact.
Numerical code for simulating the vibrational distribution function in an RF excited slab CO laser with diffusion cooling is developed. Spatial distributions of the small signal gain on the fundamental and first overtone for different vibration-rotation transitions were obtained. Dependence of gain on the wall temperature, input power and gas mixtures was studied.
Design of autonomous mobile high power CO2 gas dynamic laser (GDL) using regenerative heat exchangers for heating of laser mixtures optimized in composition was presented. A mobile laser is designed specially to be mounted in standard railway platforms. Various applications of mobile lasers in civil engineering were discussed. Economical aspects of exploitation of mobile CO2 GDL were analyzed.
Studies of vibration-vibration exchange in CO molecules excited up to vibration quantum numbers v=20 are performed both theoretically and expethnentally. New kinetic model taking into account muhi-quantum VV exchange in temperature range T=100Ö300K is described for the first time. Description of the experimental methodology allowing for studies of effects of relaxation of the vibrational distribution after a sudden disturbance is given. The disturbance of the vibrational distribution is produced by Q-switched short pulse of single line radiation in fundamental band The relaxation is studied by measuiing laser pulse energy of the second pulse initiated by resonator Q-switching produced with variable time delay relative to the first pulse. A set of kinetic rate constants accepted in the model for various gas temperatures, vibration level numbers and number of exehanged vibration quanta from 1 to 4 is presented. Good agreement between experiniental data and results of the advanced theory is the first direct evidence in support of multi-quantum exchange model.
A global cosmic system may be used for solutions to the problems of earth energy in the near future. The present paper deals with prospects for using the various gas lenses for cosmic power systems. A reflection coefficient n dependence of the inert gases from pressure is used in the gas lenses. The refractive index n of a gas is a function of pressure and temperature. The gas lenses with general diameters 5-15 m with focal distances which are equal to the cosmic orbit heights, are discussed. For the constant laser beams the lens covers can be coated with long-lasting polymeric and no fragile materials. The gas lenses without any covers can be used for the impulse laser beams. In this case a Joule-Thomson law must be taken into account. The gas lenses can be a good concurrent for thin film mirrors in some cases, which are being considered, as analyses have shown.
KEYWORDS: Carbon dioxide lasers, Solar energy, High power lasers, Laser optics, Laser systems engineering, Solar radiation, Laser energy, Optical pumping, Solar cells, Gas lasers
The global cosmic systems may be used for solution of problems of the Earth supply with energy in the nearest future. Such system can involve several cosmic platforms on the polar or heliostationary orbits. The present paper deals with prospects for using 3 types of the high power IR lasers for the cosmic power systems. The first laser type is a laser optically pumped by thermal radiation; it uses an intermediate 'black body' radiator heated by solar radiation and offers substantial and important advantages. The second laser type is a CO2 laser with radio frequency pumping. We can use several 33 X 30000 W lasers in one module for approximately 1 MW cosmic laser system. The module of 320 X 320 m2 solar cells is needed for such laser system energy supply. The third laser type is a CO2 gas-dynamic laser. The numerical studies of carbon dioxide laser that is pumped by solar-thermal heating were made, and the output laser power approximately 1 MW was calculated. The parameters studies were conducted for this laser conception.
The paper present the result of long-term investigations of experimental industrial laser complex designed to study the possibilities of applications of high power gas dynamic CO2 laser in metallurgical technologies for repair and restoration of large scale equipment. Technical and economical aspects of industrial application of such laser systems are discussed.
KEYWORDS: Gas lasers, High power lasers, Carbon dioxide lasers, Laser applications, Resonators, Diffusers, Nitrogen, Heat treatments, Laser cutting, Control systems
The performance of high power gas dynamic laser facilities is described. The key features of design of these installations and their applications in technology are discussed. Results of gas dynamic laser test runs are provided. The GDL using heat exchangers for laser gas heating, transportable by automobile and rail road platforms, are described.
KEYWORDS: Gas lasers, Heat treatments, High power lasers, Temperature metrology, Laser applications, Laser therapeutics, Mirrors, Surface finishing, Nitrogen, Combustion
The results are presented of measurements of surface hardness and wear resistivity of rolling machine 2000 rolls which were under heat treatment by high power gas dynamic laser at Cherepovetz Metallurgy Work. Surface hardness of rolls increased from 70 HSh to 80 - 85 HSh. Wear resistivity also showed considerable increase as compared with untreated rolls.
The results are presented of computer modeling jointly with preliminary results of experimental investigations of sequentially Q-switched frequency selected CO laser. Calculations show the essential difference in pulse form and inversion restoration time between the models of single- and multi-quantum vibrational exchange kinetics.
KEYWORDS: Gas lasers, High power lasers, Laser applications, Cooling systems, Head, Control systems, Carbon dioxide lasers, Laser cutting, Prototyping, Ecology
The method is proposed for calculation of lasers with unstable resonators which is based on Chebyshev polynomial approximation of nonlinear gain in ray coordinates of opposite waves simultaneously. Method is applied to calculation of gas dynamic laser which is known as active media with strongly nonuniform intensity distribution in unstable resonator.
The results on investigation of UV ((lambda) equals 271 nm) Cu vapor laser sum frequency ((lambda) 1 equals 510 nm, (lambda) 2 equals 578 nm) generation in crystal DKDP are presented. For interaction type ooe the mean UV power about 0.2 W and conversion efficiency (eta) approximately equals 2.5 + 3% are obtained for laser mean power about 7 W. Beam divergence, yellow and green line pulse amplitudes and relative delay are of key importance for sum frequency generation. Optimization of standard 20 W mean power Cu vapor laser was necessary for efficiency frequency conversion. The possibility is shown to create 5 divided by 10 W source of UV radiation, using Cu vapor laser sum frequency generation in DKDP.
The performance of high power gas dynamic laser facility for application in technology of heavy industry branches using high energy consumption and large scale equipment is described. Design of supersonic diffuser which allowed to obtain high pressure recovery is presented. Preliminary results of gas dynamic laser test runs are provided.
The results of investigation of UV ((lambda) equals 271 nm) Cu vapor laser sum frequency ((lambda) 1 equals 510 nm, (lambda) 2 equals 578 nm) generation in crystal DKDP are presented. For interaction type ooe the mean UV power about 0.2 W and conversion efficiency (eta) is congruent to 2.5 divided by 3% are obtained for laser mean power about 7 W. Beam divergence, yellow and green line pulse amplitudes, and relative delay are of key importance for sum frequency generation. Optimization of standard 20 W mean power Cu vapor laser was necessary for efficient frequency conversion. The possibility of creating 5 divided by 10 W source of UV radiation is shown, using Cu vapor laser sum frequency generation in DKDP.
The performance of a high power gas dynamic laser facility for application in technology in branches of heavy industry using high energy consumption and large scale equipment is described. The design of a supersonic diffuser which allowed us to obtain high pressure recovery is presented. Preliminary results of gas dynamic laser test runs are provided.
The new kinetic model of CO laser is developed. The basis of the model is multiquantum vibrational exchange rate constants given by Billing. The full Billing model of multiquantum VV exchange gives rise to satisfactory coincidence with experimental data on vibrational distribution function without any fitted parameters. Computer models of vibrational kinetics for CO containing mixtures are currently widely used in the analysis of problems of highly nonequilibrium vibrational excitation and in investigations of CO lasers. Until now only the single quantum VV exchange models were considered. For single quantum processes CO(v) + CO(u) yields CO(v - 1) + CO(u + 1) the rate constants (RC) are usually calculated using expressions, based on the first order perturbation theory assumptions. The parameters of well known theoretical expressions are fitted thereafter to get the magnitude and vibrational quantum number dependence of RC, measured experimentally. The RC, extended in this way to VV exchange of highly excited molecules, grow rapidly with v,u and exceed gas kinetical RC at rather low v,u > 7 for quasi-resonance exchange. Thus the validity of the first order perturbation theory expressions breaks and vibrational kinetics models using these RC become doubtful for relatively low levels. Nevertheless, these RC were widely used in practical calculations of CO laser kinetics. Their justification was in satisfactory agreement with measurements of vibrational distribution function (VDF), available in the literature.
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