STUDY OF ABERRATION CORRECTION IN 2 TYPES OF ELECTROSTATIC LENSES

A detailed comparative study is carried out of chromatic and spherical aberration in a crossed lens and in a lens formed by four cylindrical electrodes, the two inner ones of which are cut into four symmetrical longitudinal sections. The study was performed by numerical modeling. The possibility of simultaneous correction of both types of aberratio n in a linear image is demonstrated. A comparison is made with an equi valent axisymmetric lens. (C) 1997 American Institute of Physics.