Abstract
Several models of electrostatic mirrors are investigated; field distortions due to the entrance and exit slits are taken into account by carrying out exact solutions of the Laplace equation. The Dirichlet problems solved may be regarded as samples of a class of boundary value problems in a plane. The iterative method used throughout this paper enables contiguous solutions to be connected through a ``broken'' equipotential line. The results are presented in the form of recursion formulas allowing coefficients of a given order to be calculated as functions of lower order coefficients.