Generation of IR radiation on the basis of coherent Raman mixing in a vibrator is examined. It is shown that the use of a vibrator makes possible a significant (10 to 100 fold) gain in generation efficiency, particularly in the long-wave region.
Show AbstractIt is suggested that nonlinear acoustic waves excited by distributed sources be analyzed by a nonhomogeneous equation of simple waves. An analytic description is obtained of the generation of intensive sound in a periodically strictive field, produced by two head-on laser beams. A set of coupled quasilinear equations describing the behavior of the incident and reflected waves in a slightly nonhomogeneous medium is obtained. It is shown that the mathematical tools developed in the present paper are suitable in the case of periodic nonhomogeneities.
Show AbstractThe effect of the parameters of the active medium of a gasdynamic laser on the optimal parameters of an optical vibrator and its energy efficiency are investigated analytically. The results are of practical significance for designing optical vibrators of gasdynamic lasers.
Show AbstractA method is suggested for determining the potential of the nuclear N-N interaction from analysis of experimental data on nucleon-induced deutron decay at low energies on the basis of an exact solution of the integral equations of the three-body problem. To perform this study we measured the two-dimensional spectra of coincidence of protons from the d + p → p + p + n reaction with deutron energies of 14.2 and 12.8 MeV at different proton angles of emission.
Show AbstractThe article presents a derivation of a formula for the intensity of radiation due interference in a synchrotron and undulator. It is shown that the radiation intensity is a function of the parameters of the coordinate and velocity distribution of particles. Exponential damping of radiation at high frequencies is controlled by the ratio of the minimum spatial parameter of the beam to the emitted wavelength.
Show AbstractThe density of electron states of binary alloys with short-range order, calculated in the cluster approximation of the coherent-potential method, is used for determining the configuration part of the total energy of solid solutions. On the basis of this we estimated the sign of the short-range order parameter at the first coordination sphere in certain systems of transition elements. The values of these parameters for the majority of the alloys under study were found to be of the same sign as the experimental results, obtained by diffusive scattering methods.
Show AbstractThe variation in the rapid electron energy distribution function vs the location of the observation point in a low-pressure discharge in helium is investigated. The helium pressures were 2.5 * $10^{-2}$,5 * $10^{-2}$, 0.3 and 0.1 mm Hg, $i_{dis}$ = 25 mA. The distribution function was calculated from dis measured spectral line intensities by solving the invesrse problem using the regularization method.
Show AbstractThe principal characteristics of Al—SiО$_2$/Si_{3}$N$_{4}$—Si based film-type MIS varactors suitable for operation within the rf range are examined. Results of an experimental study of a two-circuit balanced parametric oscillator employing MIS varactors are presented. It is established that this device differs in a number of ways from the familiar parametric oscillator employing barrier-type varactors.
Show AbstractExperimental results are presented on the study of photoinduced formation of droplets in thin layers of solutions and melts of certain molecular compounds. When a thin layer of melt or solution with open surface was irradiated in a tray, we observed stratification of the liquid, resulting in the formation of an isolated moving droplet, which is preceded by appearance of surface irregularities and break of the film due to local increase in the surface tension attendant to evaporation of the solvent. The droplet follows the light spot on the tray surface and is enriched by the less volatile component of the solution. The motion of the droplet is induced by movement of the wetting field in the field of the temperature gradient.
Show AbstractX-ray analysis of polycrystals is employed for investigating the effect of isomorphic replacement of manganese by copper in the Еr(Mn$_{1-x}$Cu$_{x}$)$_2$ system on the stability of the hexagonal, densely-packed Cl4 structure. It is established that isomorphic replacement of manganese by copper destabilizes the Cl4 structure and results in the formation of deformation and twinning type packing defects. The concentration of packing of both types for Intermetallic compounds of both types is determined experimentally.
Show AbstractPaired collisions in the motion of stars (material points), moving in the three-dimensional space are regularized. It is assumed that a certain part of stars moves in a spherical homogeneous cloud (core) of a given density; another part of stars moves in a homogeneous concentric spherical layer (corona), surrounding the core and having a lower density. The remaining part of the stars moves in the free space. The KS transformation is applied for obtaining regular differential equations of motion, which are used in investigating the evolution of specific stellar systems.
Show AbstractThe generation of the second harmonic of laser radiation in polydomain $Ba_{2}NaNb_{5}O_{15}$ crystals is investigated. Diffuse scattering of the second harmonic is observed in crystals with disordered domain structure, consisting of microdomains. It is concluded that the dimension of acicular microdomains in the direction of the polar axis of the crystal is about 10μm, whereas their transverse dimensions range from 1 to 3 μm. Crystals with periodic laminar domian structure (with a period of 12 μm) exhibit quasisynchronous, noncolinear second harmonic generation with angular width of generation peak of 22'. Such a process can be employed for laser frequency transformation. The second harmonic generation in polydomain barium-lithium and potassium-lithium niobates was also investigated. The results obtained for these materials are analogous to those for $Ba_{2}NaNb_{5}O_{15}$. The reasons for similarity of domain structures of the investigated crystals are discussed.
Show AbstractThe symmetry of solutions and the symmetry of the first integrals of the restricted three-body problem in Nechvile coordinates is examined. The equivalence between the symmetry of solutions and the symmetry of the first integrals is shown. The existence of two families of selfsymmetric solutions, each of which is a function of three arbitrary parameters is proven. An analogous study is performed for the rectilinear three-body problem.
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