Calculation of electric field in two-dimensional arrangements by the method of multipole images

This paper presents the method of images for calculating electric field in two-dimensional arrangements. The method utilizes multipoles as the images to satisfy boundary conditions. The images are given for planar or cylindrical boundaries between two dielectrics and for those between a dielectric and a conductor. We introduce the use of three kinds of multipole re-expansions, which enables the calculation of images in complicated arrangements. The method has a clear advantage over using only line charges or line dipoles when the arrangement under consideration consists of more than two objects. Calculation examples are given to demonstrate the application of the method. The calculation results show that in an arrangement where the field is highly non-uniform, high accuracy can be attained by using the method.