The effect of the character of electron reflection on the electromagnetic properties of an inhomogeneous spherical particle

The magnetic absorption cross section of a small spherical particle with a dielectric core and a metallic shell is calculated. The general case is considered when the ratio of the radius of the dielectric core to the total radius of the particle may take arbitrary values. The condition of specular-diffuse reflection of conduction electrons from the surfaces of the metal layer of the particle is chosen as the boundary conditions of the problem. The limit cases are considered, and the results are discussed.     

Effect of electron reflection from the surface on the electromagnetic properties of cylindrical particles

The cross section of the absorption of a magnetic field by a cylindrical metal particle is calculated. The general case when the ratio of the electron mean free path to the particle transverse size may take arbitrary values is considered. The boundary conditions imply the mixed mirror-diffuse reflection of electrons from the inner surface of the particle. The limiting cases are considered and results obtained are discussed.     

Absorption of electromagnetic radiation by an inhomogeneous spherical particle

The cross section of absorption of electromagnetic radiation by an inhomogeneous spherical particle is calculated. The general case of an arbitrary value of the ratio of the particle radius to the radius of the dielectric core is considered. The condition of diffuse reflection of electrons from the inner and outer surfaces of the metal layer of the particle is taken as the boundary condition of the problem. The limiting cases are considered and the results obtained are discussed.     

Propagation and reflection of an electromagnetic wave in a hot inhomogeneous plasma

Using the WKB method a local dispersion equation of a right-hand circularly polarized wave and an expression for its electric field are derived, the wave having frequency smaller than the electron cyclotron frequency and propagating in a hot inhomogeneous plasma. The density gradient of the plasma is constant and parallel to an external magnetostatic field. Further the reflection coefficient of this wave is derived.Stimulating discussions with Dr. J. Václavík are gratefully acknowledged.     

Ponderomotive nongradient force acting on a relativistic particle crossing an inhomogeneous electromagnetic wave

The ponderomotive force acting on a relativistic charged particle crossing an inhomogeneous electromagnetic wave is investigated numerically and analytically. The initial velocity of the particle is perpendicular to the electric field vector of the wave and to the direction of its propagation. The wave has zero gradient in the direction of propagation and is inhomogeneous in both transverse directions. It is shown that the ponderomotive force acting on the particle is parallel to the wave vector. The magnitude of the force is determined not only by the extent of wave inhomogeneity in the direction of the translational motion of particle, but also by its inhomogeneity in the transverse direction. It is found that the trajectory of a particle is determined by the action of ponderomotive forces as well as by its drift in a nonuniform field.     

Dependence of the electric conductivity of a thin cylindrical wire in a longitudinal magnetic field on the character of electron reflection

The electric conductivity of a cylindrical metal wire in a longitudinal magnetic field is analyzed with regard to the specular-diffuse boundary condition for electrons. Based on the analytic solution obtained, a theoretical interpretation is given to the experimental data on the magnetoresistance of a thin cylindrical wire. An efficient method for determining the specular reflection coefficient of metal surfaces is proposed.     

Volume Fresnel reflection of electromagnetic waves in three-dimensionally inhomogeneous media

Eikonal approximation is used to derive equations describing propagation of monochromatic electromagnetic waves in a three-dimensionally inhomogeneous medium, including volume Fresnel reflection from inhomogeneities. The analysis is based on a locality principle. Separation into reflection and transmission effects is performed. The former effects are found to be isotropic, whereas the latter are anisotropic and depend on interference phenomena. Interference effects lead to violation of the Rytov law of polarization rotation. Brewster phenomena in layered and three-dimensionally inhomogeneous media are shown to occur under different conditions.     

Symmetry properties of the polarizability matrix of an inhomogeneous electron gas

The properties of the polarizability matrix of an inhomogeneous electron gas in nonconducting crystals, are subjected to group-theoretical analysis. The analytical properties of the eigenvalues and eigenvectors of the polarization operator (intrinsic polarizabilities and intrinsic densities) are discussed. It is shown that intrinsic densities transformed with respect to the vector representation of the point symmetry group of the crystal are excited in an external homogeneous electrical field. The acoustic sum rule for a dielectric matrix is obtained as a consequence of invariance relative to an infinitely small shift of space.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 84–89, June, 1989.     

Absorption of electromagnetic radiation by a cylindrical metal particle

The cross section of the absorption of electromagnetic radiation by a cylindrical metal particle is calculated. The calculation is performed in the low-frequency limit, in which the contribution of eddy currents to the absorption dominates, and for comparatively small particles (with radii of ≈10 nm), which allows us to neglect the skin effect. The case when the mean free path of electrons in the metal bulk substantially exceeds the radius of the cylindrical particle is considered in detail. The specific absorption cross sections for spherical and cylindrical particles are compared.     

Equation of motion of a particle in an external electromagnetic field in cylindrical coordinates

Translated from Isvetiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 34, No. 4, p. 435, April, 1991.     

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提出碰撞吸收型等离子体的等效折射指数,重新计算了折射角,并与利用常规方法得到的折射角进行了比较。分析了等离子体密度和碰撞频率对折射角的影响。考察了斜入射电磁波在吸收型等离子体中的折射特性,并以一维非均匀碰撞吸收型等离子体为例,对斜入射电磁波的反射特性进行了考察。结果表明,等效折射指数的概念涵盖了入射角度的影响,在考察斜入射时更准确、便捷。     

Scattering of a plane inhomogeneous electromagnetic wave by a spherical particle

We extend an analytical solution for the problem of diffraction of a plane wave by a spherical particle to the case of an inhomogeneous wave. Numerical examples showing a significant change in the scattered-wave structure compared with the case of diffraction of a homogeneous wave are presented. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 49, No. 1, pp. 72–81, January 2006.     

Relativistic effects on electromagnetic wave propagation in a cold inhomogeneous electron plasma

We construct a method which permits to investigate the propagation of a travelling wave in different cases. We present the results we obtained in the case of an inhomogeneous plasma taking into account relativistic effects.     

Special features of absorption of electromagnetic radiation by a cylindrical particle

The cross section of electromagnetic radiation absorption by a cylindrical metal particle was calculated. No limitations were imposed on the relation between the electron mean free path and the particle size. Specific absorption cross sections of cylindrical and spherical particles are compared. The results of the numerical calculation are presented graphically.     

Interaction of electromagnetic radiation with a cylindrical particle of finite length

The magnetic absorption cross section of a cylindrical metal particle of finite length is calculated. A general case is considered when the ratio of the transversal dimension of a particle to its length may take arbitrary values. Diffuse reflection of electrons from the internal surface of a particle is chosen as the boundary condition for the problem. Limiting cases are considered, and the results are discussed.     

Kinetic energy of an inhomogeneous electron gas

It is well known that the kinetic energy of a system of N noninteracting particles in an external field V(r) in the nondegenerate ground state is a universal functional of the particle density (r) [1]. However, the explicit form of this functional is defined only for a certain class of functions (r). In particular, in the case of an almost constant or a slowly varying density we obtain the wellknown Thomas-Fermi-Weizsäcker-Kirzhnits functional [1, 2]. In [3] the kinetic energy functional of an electron in an atom is obtained in the WKB approximation. The kinetic energy of electrons with quantum numbers n andl is represented as the sum of two terms. The first term is written in the form of the density of the electrons with the given quantum numbers times some orthogonalized pseudopotential, which takes into account the orthogonality of their wave functions with respect to the core (its form is discussed below). The second term is the intrinsic kinetic energy of the electrons. The introduction of an orthogonalized pseudopotential is very convenient for the calculation of atomic properties [4, 5]. It is therefore of great interest to extend the results of [3] to the case of an electron gas in a metal and to obtain an expression for its orthogonalized crystalline pseudopotential. The solution of these problems is the aim of the present paper.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 117–120, July, 1977.