共查询到20条相似文献,搜索用时 46 毫秒
1.
《Waves in Random and Complex Media》2013,23(3):336-348
Abstract Using dielectric permittivity tensor of the magnetized prolate plasma, the scattering of long wavelength electromagnetic waves from the mentioned object is studied. The resonance frequency and differential scattering cross section for the backward scattered waves are presented. Consistency between the resonance frequency in this configuration and results obtained for spherical plasma are investigated. Finally, the effective factors on obtained results such as incident wave polarization, the frequency of the incident wave, the plasma frequency and the cyclotron frequency are analyzed. 相似文献
2.
I.A. Vasilieva 《Optics Communications》2008,281(15-16):3947-3952
A simple relationship between the total scattering cross section and the normalizing constant of the scattering matrix for the general case of an arbitrary scattering particle and elliptically polarized incident radiation is obtained. The polarized radiation is described by the Stokes parameters I, Q, U, V. The obtained relationship is a consequence of two forms of energy conservation. The first one is in terms of the total scattering cross section. The other one involves the normalizing constant of the scattering matrix. The obtained relationship contains dimensionless integrals of the radiation scattered over all directions of scattering. The integrals depend on the elements of the first row of the scattering matrix and on the relative values of the Stokes parameters of the incident radiation. In the case of cross section, the incident radiation is assumed to be a plane wave. In the case of normalization constant, the incident radiation is assumed to be a convergent beam. The possible dependence of the scattering integrals on specificities of the particle illumination is taken into account in the obtained relationship. The relationship may be helpful in the various cases. So, the relationship allows one to determine any of the two characteristics of the scattering process under investigation, cross section or normalizing constant, via the other one. The relationship can be used for obtaining the scattering integrals and for analyzing the influence of the incident radiation polarization on cross section and normalizing constant. 相似文献
3.
M. Ya. Agre 《Optics and Spectroscopy》2002,92(4):499-504
A compact expression for the cross section of scattering of an arbitrarily polarized light by aligned atomic systems is obtained, in which the dependence on the geometric parameters and the Stokes parameters specifying the state of partial polarization of the incident radiation is represented in explicit form. The effect of atomic alignment and the processes of dissipation of the light energy on the polarization specific features and the angular distribution of the scattered light is investigated. In particular, it is shown that, if a dissipative channel is accessible, the angular distribution and the degree of linear polarization of scattered light depend on the degree of circular polarization of the incident radiation η2. Dissipative processes also induce the circular polarization of the light scattered by aligned atoms when η2=0. 相似文献
4.
A. V. Korol A. G. Lyalin O. I. Obolensky A. V. Solovyov I. A. Solovjev 《Journal of Experimental and Theoretical Physics》2002,94(4):704-719
A completely relativistic mechanism for describing polarization bremsstrahlung caused by an elastic collision of a charged particle with a many-electron target was suggested. Multipole expansions for the amplitude and cross section of the process taking into account radiation lag effects were obtained. Including higher order multipoles was shown to result in substantial asymmetry of the angular distribution of emitted photons compared with the dipole case and in a noticeable change in the spectral characteristics of polarization radiation. The cross section of polarization bremsstrahlung was found to increase logarithmically as the energy of incident particles grew. 相似文献
5.
M. Ya. Agre 《Journal of Experimental and Theoretical Physics》2001,93(3):491-498
A compact expression is derived for the cross section of scattering of arbitrarily polarized light by oriented atomic systems, in which the dependence on the geometric parameters and on the Stokes parameters preassigning the state of partial polarization of incident radiation is explicitly separated. It is found that the cross section of any photoprocess accompanied by photon absorption (stimulated emission) contains the sum of the products of the circular and linear dichroisms of the process by the respective Stokes parameters. The effect of the atomic orientation and of the dissipation of light energy on the polarization singularities and angular distribution of scattered light is investigated. In particular, it is demonstrated that, in the case of an open dissipation channel, the angular distribution remains dependent on the atomic orientation even in the case of zero degree of circular polarization of scattered radiation. 相似文献
6.
Formulas are derived for the differential effective scattering cross section for elliptically polarized radiation, the magnetic moment being initially at rest with the spin oriented. The cases of linear and circular polarization are considered in detail, as is the case of unpolarlzed radiation. The formulas give the polarization of the scattered radiation as a function of the incident polarization and of the spin orientation.We are indebted to Prfessor A. A. Sokolov for proposing the topic and for discussing the results. 相似文献
7.
M. Ya. Agre 《Optics and Spectroscopy》2003,94(2):163-169
An expression for the cross section of light scattering by axisymmetrically aligned atomic systems is derived in a compact form. The cross section under consideration is proportional to the state multipole of the fourth rank. The effect of the second-order alignment determined by the fourth-rank state multipole on the polarization and the angular distribution of scattered light is investigated. The polarization of incident light can be arbitrary and, in the general case, is specified by the Stokes parameters. In particular, it is demonstrated that the second-order alignment cannot induce circular polarization of scattered light and does not influence the dissipation-induced effects of circular dichroism associated with the first-order alignment but leads to a change in the angular distribution and the degree of linear polarization of the scattered light. 相似文献
8.
Analysis of the relativistic scattering of electromagnetic radiation by inhomogeneities of the velocity of the motion of a medium is carried out. The characteristics of the scattering of a plane monochromatic wave by a rotating dielectric cylinder surrounded by an immobile medium with a refractive index the same as that of the cylinder are calculated. The differential scattering cross section is found. It is shown that the rotation of particles with actual parameters may yield a significant contribution to the scattering, of the same order of magnitude or larger than the contribution made by Rayleigh and Raman scattering. 相似文献
9.
M. Ya. Agre 《Journal of Experimental and Theoretical Physics》2002,95(2):199-205
A compact expression is derived for the part of the cross section for light scattering by axisymmetrically polarized atomic systems proportional to the third-rank state multipole. The effect of the second-order orientation determined by this state multipole on the polarization and angular distribution of the scattered light is studied. The polarization of the incident light can be arbitrary and is specified by the Stokes parameters. A number of orientation effects in the scattering process are shown to be induced precisely by the second-order orientation. In particular, when nonpolarized light is scattered by an oriented atom, the scattering intensity in the perpendicular direction depends on the second-order orientation alone. The second-order orientation also preserves circular dichroism in the linear polarization of the forward-and back-scattered light. 相似文献
10.
Ondarza-Rovira R. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》2001,29(6):903-906
The relativistic equations of motion of the interaction of a charged particle with an electromagnetic wave of elliptic polarization propagating along the direction of an external and constant magnetic field are solved in exact form. The method of solution is straight forward and allows to recover results previously reported in the literature 相似文献
11.
The scattering of linearly or circularly polarized light from a semi-infinite randomly inhomogeneous medium is considered.
Using the Monte Carlo method, it is shown that, in the case of a wide front of incident and scattered optical radiation and
irrespective of the degree of scattering anisotropy, the copolarized component of backscattered light dominates the cross-polarized
component for the linear polarization and the cross-polarized component dominates the copolarized component for the circular
polarization. If the beams of incident and scattered radiation are spatially separated and the size of scatterers exceeds
the wavelength, the circular copolarized component dominates the cross-polarized one. A similar effect of the change in direction
of the rotation of the plane of polarization in relation to the size of scatterers is revealed for pulsed radiation. 相似文献
12.
13.
V. V. Lyuboshitz V. L. Lyuboshitz 《Journal of Experimental and Theoretical Physics》2000,91(4):673-681
The quantum-mechanical Aharonov-Bohm effect in the diffraction of charged particles by a toroidal solenoid containing a magnetic field is investigated. The total and differential elastic scattering cross sections depend on the magnetic flux inside the solenoid, even in the presence of a “black” ring-shaped screen which prevents charged particles from entering the region where the magnetic field is localized. Relations describing the momentum-transfer cross section for the elastic scattering of charged particles by a toroidal solenoid are obtained in the eikonal approximation and in a unitary model of scattering with a sharp jump in the partial amplitudes. The momentum-transfer scattering cross section is proportional to the average transfer of the longitudinal momentum of the scattered particle and can be expressed in terms of a force operator. It is shown that in the absence of a screen the momentum-transfer scattering cross section of toroidal solenoid is indeed determined only by the part of the incident beam that intersects the inner region of the toroidal solenoid, where the magnetic field intensity and, therefore, the Lorentz force are nonzero. At the same time, the momentum-transfer cross section for the scattering of charged particles by a toroidal solenoid covered by a “black” ring-shaped screen does not depend on the magnetic flux inside the solenoid and is identical to the momentum-transfer cross section for diffraction by the same screen. The contribution from scattering by an opening in the screen, which depends on the magnetic flux, is completely compensated by the contribution of the interference of the scattering amplitudes of the opening and the “black” screen. 相似文献
14.
N. F. Shul’ga V. V. Syshchenko 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2007,1(2):141-146
Equations for the cross section and polarization of the coherent bremsstrahlung emitted by relativistic electrons and positrons in crystals are obtained taking into account the contribution from the second-order Born approximation. The radiation cross section and polarization in the field of the atomic plane is considered as a function of the charge sign of the particle. 相似文献
15.
A. V. Borovskii V. V. Korobkin O. B. Shiryaev A. L. Galkin 《Journal of Experimental and Theoretical Physics》1998,86(6):1114-1121
A theory of the propagation instability of plane, monochromatic, circularly polarized electromagnetic waves of relativistic
intensity in matter is developed for a spatially three-dimensional geometry including arbitrary polarization of the scattered
radiation. Harmonic generation owing to striction and relativistic nonlinearity is examined, as well as scattering owing to
electron recoil, the decay instability of the harmonics with formation of scattered electromagnetic waves (Stokes components
of the stimulated Raman scattering and plasmons), the interaction of electromagnetic waves in the plasma (antistokes stimulated
Raman scattering), and the generation of a radiative continuum. The transition of the three-dimensional theory to a one-dimensional
problem in the nonrelativistic limit is discussed.
Zh. éksp. Teor. Fiz. 113, 2034–2046 (June 1998) 相似文献
16.
This paper discusses the Raman scattering of light in an anisotropic crystal in the crystal optics approximation, taking into
account local fields acting on the molecules. It shows that the effect of the local field reduces to the introduction of the
effective Raman polarizability tensor of the molecules, which depends both on the properties of the molecules themselves and
on the characteristics of the crystal at the frequencies of the incident and scattered waves. Raman scattering cross sections
are obtained in a uniaxial crystal for various types of incident waves. It is shown that, in the case of an extraordinary
incident wave, the local field substantially affects how the cross section depends on the direction of incidence.
Zh. éksp. Teor. Fiz. 112, 180–191 (July 1997) 相似文献
17.
I. M. Sokolov D. V. Kupriyanov M. D. Havey 《Journal of Experimental and Theoretical Physics》2011,112(2):246-260
Based on the developed quantum microscopic theory, the interaction of weak electromagnetic radiation with dense ultracold
atomic clouds is described in detail. The differential and total cooperative scattering cross sections are calculated for
monochromatic radiation as particular examples of application of the general theory. The angular, spectral, and polarization
properties of scattered light are determined. The dependence of these quantities on the sample size and concentration of atoms
is studied and the influence of collective effects is analyzed. 相似文献
18.
V. A. Astapenko 《Journal of Experimental and Theoretical Physics》1999,88(5):889-894
The polarization dependence of the stimulated bremsstrahlung and inverse bremsstrahlung (SBIB) of quasiclassical electrons
on highly charged ions with a core is calculated in the approximation of a specified Coulomb current. Emission frequencies
close to an eigenfrequency of the ion core are considered. The contributions of the static and polarization channels are taken
into account in the amplitude of the process. When the nondipole nature of the interaction between the incident particle and
a resonant transition in the ion core is taken into account, interference between these channels causes the spectral-amplitude
characteristics of the process to assume a specific dependence on the angle α between the electric field intensity vector of the electromagnetic wave and the initial velocity vector of the incident particle.
This dependence, which persists after integration of the cross section over the scattering angle of the incident particle,
causes interference effects, viz., asymmetry of the line shape and dips in the dependence of the SBIB cross section on electric
field intensity, to appear for α=π/2 and significantly reduces them for α=0.
Zh. éksp. Teor. Fiz. 115, 1619–1629 (May 1999) 相似文献
19.
A. V. Akopyan 《Radiophysics and Quantum Electronics》1995,38(10):652-658
The resonance radiation in Compton scattering of an electromagnetic wave by a fast relativistic electron moving in a given magnetic field is investigated with allowance for deceleration by the radiation. A general expression for the electric field of an arbitrarily polarized scattered wave is derived within the framework of small-perturbation theory. It is shown that the resonance peak in the scattering cross-section is caused by the small radiation friction. The dependence of the resonance line width on the characteristic parameters of the problem is examined. The scattering of a given polarized wave is considered, and the degree of linear polarization of the radiated wave under resonance is determined.Institute of Radiophysics and Electronics, Armenian Academy of Sciences, Erevan. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 38, No. 10, pp. 1001–1011, October, 1995. 相似文献
20.
《Physics letters. A》2002,299(4):331-336
A version for intense γ-ray radiation based on the multiphoton scattering of strong laser radiation on relativistic particle beam channeled in a crystal is proposed. The incident laser beam and charged particles beam are counter-propagating and the laser radiation is resonant to the energy levels of transversal motion of channeled particles. 相似文献