Boundary effects in Cherenkov radiation
Boundary effects in Cherenkov radiation
复制标题
DOI：
10.1103/physrevb.69.155420
复制
发表时间：
2004-04-01
影响因子：
3.7
通讯作者：
Yamamoto, N
中科院分区：
文献类型：
--
作者：
de Abajo, FJG;Rivacoba, A;Yamamoto, N
针对不同形状的样品，分析了介质边界对快点电荷在材料内部或附近运动时产生的切伦科夫辐射的影响。给出了电荷在平面和非平面附近运动的计算。发现即使当外部电荷移动到半无限介质之外时，也会产生铬。对于在平面边界附近运动的电荷，反射辐射会干扰直接CR，导致发射几率作为相对于界面的撞击参数的函数而发生振荡。薄膜导模是由穿透电子激发的，我们的计算与已有的实验符合得很好。对于通过半径越来越大的圆柱体或球体中心的电荷，可以恢复发射概率中的体积极限。由于在介质球的响应中包含了延迟效应，解释了最近在介电球附近通过的电子的能量损失的实验。这些效应导致了辐射能量损失的有效渠道。最后，提出了空洞包裹体中CR的绕射作为一种工具，以提供关于原本难以接近的埋藏结构的信息。
The effect of dielectric boundaries on the Cherenkov radiation (CR) produced when a fast point charge moves inside or near a material is analyzed for different shapes of the sample. Calculations are offered for a charge moving near both planar and nonplanar surfaces. CR is found to be produced even when the external charge moves outside a semi-infinite medium. For charges moving near planar boundaries, the reflected radiation interferes with the direct CR, leading to oscillations in the emission probability as a function of the impact parameter relative to the interfaces. Thin-film guided modes are excited by penetrating electrons and our calculations agree reasonably well with available experiments. The bulk limit in the emission probability is recovered for charges passing by the center of cylinders or spheres of increasingly large radius. Recent experiments of energy loss of electrons passing near dielectric spheres are explained thanks to the inclusion of retardation effects in the sphere response. These effects lead to an efficient channel of radiative energy losses. Finally, the diffraction of CR in void inclusions is proposed as a tool for providing information on otherwise inaccessible buried structures.