Study of aberration correction in two 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 aberration in a linear image is demonstrated. A comparison is made with an equivalent axisymmetric lens. Zh. Tekh. Fiz. 67, 92–96 (August 1997)