Focusing of atomic and molecular beams in electric fields of various configuration

The properties of an axisymmetric electrostatic lens used for focusing atomic or molecular beams were studied. The lens was formed by a dip in an electric field in the axial direction. Two types of interaction between the particles and the electric field were studied: quadratic and linear in field. An analytical approximation of the dependence of the focal distance of the lens on the beam energy and the parameters of the electric field was obtained. Chromatic and spherical aberrations of the lens were determined.