Two-Directional Focusing of Charged Particles with a Sector-Shaped, Uniform Magnetic Field

Publisher Website
Google Scholar
Abstract
For a sector‐shaped, uniform magnetic field with source and detector outside the field, the non‐uniform fringing fields can be employed to give simultaneous focusing of charged particles in two perpendicular directions. Equations for determining the position of the doubly‐focused image are developed and graphs are given for some representative arrangements. This double focusing can be combined with the methods recently developed for second‐order focusing, to increase further the useful solid angle of a uniform‐field mass or momentum analyzer. Fringing‐field focusing can also be used in concentrating to a point a parallel beam of finite cross section.