Corrector for the correction of first-order colour aberrations, first grade

摘要

the invention relates to a corrector for correcting aberrations of energy dependent first order, first degree and the u00f6ffnungsfehlers third order of elektronenoptischen systems.the corrector contains at least a quadrupol - septuplet (s1) with seven quadrupolen (q1 and q7), and so to a mid plane (zs) symmetrically along a straight line axis excitable are arranged. the corrector also contains at least five within the quadrupol - septuplets erregbare oktupole (o1 - 67).;in an advantageous embodiment, two quadrupol - septuplets serially arranged behind each other, with the quadrupolfelder the two quadrupol - septuplets antisymmetrisch to between two quadrupol - septuplets lying plane of excited.such a system can, in addition to the axial and auu00dferaxialen farbfehlern first order and third order geometric aberrations of the first degree and other energy dependent aberrations of the first order geometric aberrations, third grade and fifth of lins ensystems are corrected.