Achromatic beam deflector, achromatic beam separator, charged particle device, method of operating an achromatic beam deflector, and method of operating an achromatic beam separator

摘要

An achromatic beam separator device for separating a primary charged particle beam from another charged particle beam and providing the primary charged particle beam on an optical axis (142) is provided, including a primary charged particle beam inlet (134), a primary charged particle beam outlet (132) encompassing the optical axis, a magnetic deflection element (163) adapted to generate a magnetic field, and an electrostatic deflection element (165) adapted to generate an electric field overlapping the magnetic field, wherein at least one element chosen from the electrostatic deflection element and the magnetic deflection element is positioned and/or positionable to compensate an octopole influence.