Electrostatic corrector for removing color aberrations in particle lenses has a straight optical axis and two correcting pieces behind each other along the optical axis each with electrical quadrupolar and round lens fields.

摘要

Paraxial fundamental beam paths running from an object point (2) lying on-axis are guided through a lens (3) with color aberrations. A corrector has two correcting devices (4,5) with symmetrical mirrors regarding their central planes (6,7) turned on an optical axis at 90 deg opposite each other. In the center of each correcting device there are correcting pieces (8,9) each with three quadrupoles (10/11/10',12/13/12').