ELECTRON MICROSCOPE WITH AN ASYMMETRICAL IMMERSION LENS

摘要

A magnetic electron focusing lens including a first pole piece, from a back side of which low-energy electrons are injected, and a second pole piece located on a front side of the first pole piece. The first and second pole pieces are coupled to form a single magnetic circuit. The first pole piece is shaped to maximize the magnetic field at a its front side at a peak much closer to the first then to the second pole piece. The specimen is located between the first and second pole pieces near the peak of the magnetic field.