Spherical aberration corrector for use in electron microscope, has rotation correcting lens positioned within focal plane of electron trajectory formed between axially symmetric lenses

摘要

A pair of axially symmetric lenses (10',11') are placed between a pair of multipole elements (8',9'). A rotation correcting lens (12) placed in a focal plane of an electron trajectory formed between the axially symmetric lenses, acts to rotate electrons within a plane perpendicular to an optical axis.