Electromagnetic deflector

Abstract

Electromagnetic deflectors and methods for their manufacture are disclosed. The excitation coils inside such deflectors can be situated relative to each other and to an optical axis with a high degree of accuracy and precision. A pair of loop-shaped channels are formed opposite each other in the sides of a cylindrical insulating cylinder. An electrically conductive material is embedded in the channels to form a set of opposing coils operable to deflect a charged particle beam passing axially through the cylinder in one dimension. Multiple cylinders each comprising a set of opposing coils can be concentrically assembled to provide, e.g., a biaxial deflector operable to deflect the beam in an X-dimension and a Y-dimension. In such a biaxial deflector, the sets of coils are arranged perpendicular to each other. The cylinder(s) is placed concentrically inside a cylindrical outer casing made of a ferromagnetic material such as ferrite to make an electromagnetic deflector.

Dependencies are inferred from the claim text.