CALCULATION FOR GEOMETRICAL ABERRATIONS OF A DEFLECTION SYSTEM WITH A UNIFORM ELECTROSTATIC FIELD
均匀静电场偏转系统的几何象差的计算

In this paper, formulas of third geometrical deflection aberratios for an ideal uniform electrostatic field are deritved by solving the motion equations of an electron passing through this field. The results can be used not only to estimate the distortion, astigamatism and field curvature, and coma produced by a Gaussian or shaped electron beam, but also to set the original size of the deflector and determine the effect caused by the misaligument between the electron beam and the deflector. Some mistakes in Sturrock's paper (1955) are also poited out.