Electron microscope electron beam magnetic deflection system - has two saddle-type coils symmetrical to undeflected electron beam

摘要

The magnetic deflection system for the electron beam of an electron microscope has two coils in symmetrical arrangement relative to the path of the undeflected electron beam. Each coil has at least two saddle-shaped windings, matching a cylindrical surface. The windings have longitudinal parts parallel to the electron path, which are connected by cross parts describing a circular arc. The windings are mutually offset in the direction of the electron beam. The cross parts, through which current flows in the same direction, are of successively reducing length in the beam path direction, while the long parts are of indentical length. Alternatively the configuration may be such that the cross parts are of successively increasing length.