论文标题
电磁散射和衍射的经典理论教程
A Tutorial on the Classical Theories of Electromagnetic Scattering and Diffraction
论文作者
论文摘要
从麦克斯韦的方程式开始，我们得出了标量衍射和散射的Huygens-Fresnel-Kirchhoff和Rayleigh-Sommerfeld理论的基本结果。然后将这些结果扩展以覆盖矢量电磁场的情况。详细说明了著名的Sommerfeld解决方案，解决了从完美导致半平面的衍射问题。平面波从障碍物中的远场散射进行了一些细节处理，并得出了将障碍物的散射横截面与其正向散射幅度相关的散射横截面。还检查了从原本均匀的介质中从轻度不均匀性散射的情况，在第一个诞生的近似中，发现了一个相当简单的公式将远场散射幅度与宿主介质的光学特性相关联。在本文的最后一部分中处理了来自铁磁材料的中子散射的相关问题。
Starting with Maxwell's equations, we derive the fundamental results of the Huygens-Fresnel-Kirchhoff and Rayleigh-Sommerfeld theories of scalar diffraction and scattering. These results are then extended to cover the case of vector electromagnetic fields. The famous Sommerfeld solution to the problem of diffraction from a perfectly conducting half-plane is elaborated. Far-field scattering of plane waves from obstacles is treated in some detail, and the well-known optical cross-section theorem, which relates the scattering cross-section of an obstacle to its forward scattering amplitude, is derived. Also examined is the case of scattering from mild inhomogeneities within an otherwise homogeneous medium, where, in the first Born approximation, a fairly simple formula is found to relate the far-field scattering amplitude to the host medium's optical properties. The related problem of neutron scattering from ferromagnetic materials is treated in the final section of the paper.
