The physical modelling of atmospheric vortices
The physical modelling of atmospheric vortices
E.P. Anisimova, A.M. Gusev, A.A. Speranskaya, V.S. Shandin
A description of an experimental unit that realizes a model of an atmospheric vortex system is presented. The model simultaneously reproduces the velocity, temperature, and air humidity fields. Thermal effects play the dominant role in this model of vortex systems.
Show AbstractInfrared GaAs crystal light modulator with 480 MGz modulation frequency
Infrared GaAs crystal light modulator with 480 MGz modulation frequency
M.I. Zusman, E.R. Moustel
Modulation of infrared radiation with wavelength λ = 10.6 μm is experimentally observed. At a modulation frequency of f$_{m}$ = 480 MHz and modulation power of 16 W , the modulation intensity amounts to 37%.
Show AbstractAcceleration of electrons in classical cyclotron
Acceleration of electrons in classical cyclotron
L.A. Sarkysian
It is suggested that electrons as well as ions can be accelerated in a classical cyclotron. Such electron acceleration becomes possible when the cyclotron enters the microtron mode, The attainable energy of the electrons in cyclotrons with polar diameter from 1,2 to 1.5 m may amount to 30 to 50 MeV (the maximal energy of ions in existing microtrons amounts to 32 MeV). Electron acceleration in the quasi-continuous mode is possible.
Show AbstractCalculation of imaginary part of the optical potential in collective model for spherical nuclei
Calculation of imaginary part of the optical potential in collective model for spherical nuclei
F.A. Ghivopistsev, Н. Molina
The paper is concerned with the angular dependence of the imaginary part of the optical potential for even-even nuclei in the low-energy region with allowance for excitation of lower collective states of the target nucleus. It is shown that the principal contribution to Im Vopt is made by the low collective states 2$^{+}$ and 3${-}$ of the target, which completely exhaust the entire imaginary part of the optical potential in the low-energy region. According to calculations, the contribution to Im Vopt, due to formation of the compound nucleus is small.
Show AbstractOn the limit state of wave — intensive beam in plasma medium
On the limit state of wave — intensive beam in plasma medium
V.K. Grishin, S.Т. Ivanov, M.F. Кanevskii
This paper examines the wave-beam state in an infinite electron plasma at the stage when the particles are captured by the wave and undergo phase mixing. The state of the beam is described by nonlinear selfcongruent equations, the plasma remains a linear, dispersing medium. Estimates are obtained, characterizing the redistribution of the energy of the initial beam at single-mode generation of the longitudinal field by a low-density relativistic electron beam. The maximum generation efficiency amounts to 10% and is attained for nonrelativistic beams at(n$_{0}$/n$_{p}$)$^{1/3}$ ≅0,5, where n$_{0,p}$ are the beam and plasma densities. The u p и, p heating effectiveness at this stage is estimated. A comparison withresults of numerical experiments is performed.
Show AbstractSpace- polarization filtering of electromagnetic waves
Space- polarization filtering of electromagnetic waves
Yu.V. Вerezin, A.N. Talitskу
The paper examines a spatial-polarization filter (SPF)employed for supression of two-beam, partially scattered interference. The operation of the filter is based on the assumption that two interference beams have different polarizations and incidence angles. Two versions of operation of such a filter are analyzed for the caser of supression of a two-rbeam concentrated interference in receiving a partially scattered two-beam signal in the presence of additive noise. Analytic expressions, controlling the possible gain in the signal/noise ratio when using this filter are obtained.
Show AbstractEffect of electrostatic field and highfrequency vibrations on the dislocation motion in alkali-hailide crystals
Effect of electrostatic field and highfrequency vibrations on the dislocation motion in alkali-hailide crystals
N.A. Tyapunina, A.A. Svetashov
The effect of an electrostatic field on the translational motion of dislocations attendant to ultrasonic vibration is investigated. Moving dislocations were produced in an KC1 crystal by indentation and were detected by repeated etching. It follows from the experiments that the combined effect of the electrical and acoustic fields is not equivalent to the effect due to separate application of these fields. Upon combined application of both fields the number of moving dislocations and the mean length of rim rays in the dislocation rosettes is greater than upon application of only the ultrasonic field. Analysis of results shows that the electrical field increases path length and number of the moved dislocations, but has little effect on the starting stresses of translational motion of dislocations.
Show AbstractThe theory of magnetic properties for generalized model of a ferromagnetic metal
The theory of magnetic properties for generalized model of a ferromagnetic metal
A.V. Vedyaev, J.M. Neimatov
The temperature dependence of magnetization in the generalized model of a ferromagnetic metal, including the direct interaction between ferromagnetic d -electrons and d-f type exchange, is investigated. It is shown that, at sufficiently low temperature, significantly lower than the Curie temperature T$_{c}$, the temperature dependence of magnetization for a subsystem of localized electrons deviates from Bloch's "T$^{3/2}$"
Show AbstractOn the origin of a smooth random field in disordered semiconductors
On the origin of a smooth random field in disordered semiconductors
V.L. Bоnсh - Bruevich
Conditions under which one should expect the inception of a smooth random field in a disordered (amorphous or alloyed crystalline) semiconductor are examined. It is shown that such a field may arise in not too well prepared specimens.
Show AbstractThe estimation of nonlinear effects under vertical propagation of nonmonoehromatic acoustical waves in the real atmosphere
The estimation of nonlinear effects under vertical propagation of nonmonoehromatic acoustical waves in the real atmosphere
S.N. Kulichkov
The generation of a difference harmonic attending the vertical propagation in the atmosphere of two acoustic waves of close frequency is considered. Pumping of energy from the difference to the primary harmonic is possible at a certain distance from the source. The energy of the difference harmonic, after formation of a discontinuity in the primary radiat ion, tends to some constant value, determined by the ratio of the difference and fundamental frequencies. It is found that nonlinear effects manifest themselves in acoustic waves only at Mach numbers higher than some constant quantity, which depends on the values of the Knudsen number for the atmosphere.
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