IMAGE POLARIZATION AND DIPOLE-MOMENT OF A CLUSTER OF 2 SIMILAR CONDUCTING SPHERES

The method of images is applied for calculating the electric polarizab ility of a cluster of two similar perfectly conducting spheres. The im age dipole density functions, which describe the source of the field r esponse of the cluster, take the form of point and constant line dipol e distributions located on the axis connecting the two spheres. The am plitude coefficients of these sources obey recursive relations. In the present analysis, the means to determine these coefficients is provid ed along with exact results in the limiting case of contact between th e spheres. The behaviour of the total dipole moment is illustrated gra phically for different orientations of the exciting field as a functio n of the interparticle distance. The theory may be applied in the stud y of low-frequency scattering from a conducting particle pair or when estimating the average permittivity of media composed of pair clusters .