均匀电场中颗粒簇偶极矩的确定

AN ESTIMATE OF THE DIPOLE MOMENT OF PARTICLE CLUSTERS

置于均匀电场中的一簇球形颗粒，由于其内部的相互作用而耦合在一起．这致使簇的感应偶极矩与簇的几何结构，大小以及颗粒的介电常数等参量有关．试图通过已知的链的偶极矩确定任意大小长方结构的簇的偶极矩．假定颗粒链可以被具有同样偶极矩的一个等效介质球代替，并将具有空间结构的颗粒簇处理成面结构簇，再将面结构简化成一个颗粒链，从而确定簇的偶极矩．在这一过程中，通过不断增加等效球的尺寸，将颗粒间的相互作用包含在簇的偶极矩中．数值分析了立方结构簇的偶极矩。

Abstract When a cluster of particles is immersed in a uniform electric field,the particles are coupled together due to the mutual interaction among them.This interaction causes the dipole moment of the cluster to be dependent upon the spatial arrangement and relative permittivity of the particles and upon the cluster size.In this work,we attempt to estimate the dipole moment of finite cubic arrays of particles,in terms of that of particle chains which has been known.We assume that a chain may be replaced by a single equivalent sphere with the same dipole moment.With replacing the chain by equivalent sphere,a cluster is simplified to a planar array,and this planar array is simplified to a chain,then the dipole moment is obtained.Numerical calculations are performed.It is found that our results are acceptable.