Resonance Scattering of GHz Plane Electromagnetic Waves from Ring Dielectric Linear Structures

Optics and Spectroscopy - Resonance backscattering at the fundamental magnetic mode and the wave properties of linear structures consisting of subwave dielectric elements in the form of planar thin...     

Resonant Scattering of Gravitational Waves with Electromagnetic Waves

A certain class of exact solutions of Einstein Maxwell spacetime in general relativity is discussed to demonstrate that at the level of theory, when certain parametric resonance condition is met, the interaction of electromagnetic field with a gravitational wave will display certain Lyapunov instability and lead to exponential amplification of a gravitational wave train described by certain Newman–Penrose component of the Weyl curvature. In some way akin to a free electron laser in electromagnet...     

Scattering of Electromagnetic Waves by Structures Composed of a Finite Number of Three-Dimensional Perfectly Conducting Bodies

Using the method of discrete sources, we solve the problem of scattering of electromagnetic waves by structures composed of a finite number of three-dimensional perfectly conducting bodies bounded by smooth surfaces of arbitrary shape. We describe briefly the capabilities of the package of computer codes developed for calculating the scattered-field characteristics and checking the accuracy of the solution obtained. We present some results of numerical calculations aimed at analysis of the influence of the distance between the bodies on their electromagnetic interaction.     

Numerical Simulation of Electromagnetic Waves Scattering by Discrete Exterior Calculus

We show how to construct discrete Maxwell equations by discrete exterior calculus. The new scheme has many virtues compared to the traditional Yee＇s scheme： it is a multisymplectic scheme and keeps geometric properties. Moreover, it can be applied on triangular mesh and thus is more adaptive to handle domains with irregular shapes. We have implemented this scheme on a Java platform successfully and our experimental results show that this scheme works well.     

Note on Scattering of Electromagnetic Waves by Nonlinearly Screened Dust Grains in Plasmas

Although most experiments in complex plasmas correspond to non‐linear grain screening, the theoretical models of non‐linear screening have not been checked experimentally. Scattering of electromagnetic waves on a single nonlinearly screened dust grain in plasmas can serve as one of effective methods for investigation of non‐linear screening. In present paper we have developed a theory for electromagnetic wave scattering that includes both the effect of coherency of scattering for long wave range and the loss of coherency with a decrease of the wave length. It is valid for arbitrary non‐linearity in screening and demonstrates that the loss of coherency occurs for wave length less then the characteristic screening length for non‐linear screening being usually substantially larger than the linear Debye screening length. The effect is illustrated numerically using the most popular model of non‐linear screening. The dependence of the cross‐section of scattering on parameter of non‐linearity in screening is calculated numerically. The loss of coherency in scattering by a single grain can serve as effective diagnostic for checking the theoretical models of non‐linear screening. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Collective Scattering of Electromagnetic Waves from a Relativistic Magnetized Plasma

Recently, laser and microwave scatterings have become one of the important diagnostic means for plasma. Laser and microwave correlative scattering spectrum is determined by particle-density fluctuations in a weak turbulent plasma. In a relativistic plasma, on the basis of complete electromagnetic interaction between particles, a general expression for particle density fluctuations and spectra of laser and microwave scattering from a magnetized plasma are derived. The laser and microwave scattering spectra provide information on electron density and temperature, ion temperature, resonance and nonresonance effects.     

Resonant Scattering of Relativistic Outer Zone Electrons by Plasmaspheric Plume Electromagnetic Ion Cyclotron Waves

The bounce-averaged Fokker-Planck equation is solved to study the relativistic electron phase space density （PSD） evolution in the outer radiation belt due to resonant interactions with plasmaspheric plume electromagnetic ion cyclotron （EMIC） waves. It is found that the PSDs of relativistic electrons can be depleted by 1-3 orders of magnitude in 5h, supporting the previous finding that resonant interactions with EMIC waves may account for the frequently observed relativistic electron flux dropouts in the outer radiation belt during the main phase of a storm. The significant precipitation loss of ~MeV electrons is primarily induced by the EMIC waves in H＋ and He＋ bands. The rapid remove of highly relativistic electrons （〉5MeV） is mainly driven by the EMIC waves in O＋ band at lower pitch-angles, as well as the EMIC waves in H＋ and He＋ bands at larger pitch-angles. Moreover, a stronger depletion of relativistic electrons is found to occur over a wider pitch angle range when EMIC waves are centering relatively higher in the band.     

Intensity Effects in Scattering of Electromagnetic Waves by Electrons Moving in External Magnetic Field

In this paper we consider the emission processes of a relativistic electron moving in the field of a plane electromagnetic wave and in a homogeneous magnetic field. A detailed analysis of the most important characteristics of the radiation properties for arbitrary values of the magnetic field, compared with \documentclass{article}\pagestyle{empty}\begin{document}$ [H_0 = \frac{{m^2 c^3}}{{e\hbar}}]$\end{document} = 4.41.10¹³ gauss, is presented.     

Scattering of Plane Electromagnetic Waves from a Biisotropic Sphere in Vacuum

The boundary-value problem on scattering of a plane circularly polarized electromagnetic wave from a biisotropic sphere in vacuum has been solved. The coefficients for scattered and internal fields have been obtained and numerically analyzed.     

Analysis of Electromagnetic Waves Scattering by a Finite Size Dielectric and Metal Cylinder in a Rectangular Waveguide

The paper presents a rigorous solution of the scattering problem by a circular dielectric and perfectly conducting cylinders of any radius and any height in the rectangular waveguide oriented perpendicularly to a wall. The method is based on the representation of fields in waveguide and dielectric medium by cylindrical eigenfunctions and application of boundary conditions on surfaces of the cylinder to evaluate the fields inside and outside the cylinder. The reflection and transmission coefficients are expressed through the fields. As an example the reflection and transmission coefficients versus frequency for various dielectric and metallic cylinders are computed. The comparison of numerical with experimental data is presented.     

复杂媒质散射特性的FETI分析

在分析复杂媒质的电磁场散射特性时,引入有限元撕裂对接法,对包含复杂媒质在内的整个计算空间做区域分解,通过合理的代数运算,将一个三维问题转化为二维问题进行求解,减小计算的复杂度.使用Krylov求解器,避免在形成交界面系统方程时,系数矩阵中的求逆运算.两个算例结果表明有限元撕裂对接法在分析复杂媒质散射特性时的正确性和有效性.     

Electromagnetic Wave Scattering on the Structure Consisting of a Magnetodielectric Body and Thin Conductors

Russian Physics Journal - The method of auxiliary sources is used to solve the problem of electromagnetic wave scattering on the structure consisting of a magnetodielectric body and several thin...     

Scattering of an Electromagnetic Wave by a Structure Consisting of Several Perfectly Conducting and Dielectric Finite-Length Thin Cylinders

Radiophysics and Quantum Electronics - We generalize a variant of the auxiliary-source method, which was proposed earlier for solving the problem of electromagnetic-wave scattering by a structure...     

雨滴对电磁波的散射特性研究

由于重力和向上气流的作用,高速摄影显示较大的雨滴在降落过程中表现为一底部扁平、顶部圆滑的非球形对称体,已有的模型中BC模型(由Beard和Chuang提出)被认为能准确描述雨滴的形状。本文利用沿降落方向旋转对称的扁椭球体和均匀球体模拟降落中的雨滴,扁椭球体的短轴(旋转轴)与BC模型的相等,长轴通过与BC模型截面积等效法确定;利用T矩阵方法研究了水平取向的旋转扁椭球体和BC雨滴模型的散射特性,利用Mie理论计算了均匀球的散射特性,比较了半径分别为2 mm和3 mm大小的三种雨滴模型对94 GHz电磁波斜入射时的单次散射相矩阵,以及对频率为30 GHz~100 GHz电磁波的单次散射反照率,最后讨论了半径为0.5 mm~3.5 mm雨滴对35 GHz和94 GHz的后向散射函数。计算结果表明,利用均匀球模拟雨滴将带来较大误差,而利用截面积等效的旋转扁椭球体模型可以较好地模拟雨滴的散射特性。     

Bragg Scattering of Surface Waves by a Photo-Induced Array

A pattern of spots of light projected on to a semiconductor wafer creates an array of scatterers that can diffract millimeter-wavelength surface waves through 90° in agreement with the expression for Bragg reflection.     

Electrical Noises in Thin Metal Wires

The metallic micro-sized wires of gold, silver and copper with the various sizes were prepared. Their CVC, low-frequency noise, as well as the behavior and dependence of the noise spectral density on the type and sizes of metals and contacts were investigated. It is shown that the spectral density of low-frequency noise strongly depends on the dimensions of the sample. It is also shown that the spectral density of noise increases with the decrease in the diameter of the wire and with the increasing in a sample length. The dependence of the spectral density of the low-frequency noise shows that it has the contact character and is proportional to the square of the contact resistance.