Effects of Electrode Beam Radius on Properties of four-poles Electrostatic Double Lens for Point-to-Point Focus

Abstract

This study investigates the effect of selection the electric pole radius of the four poles electrostatic doublets lens on the optical property. Also, a comparison between the optical property and performance of two lenses with different electrode radius was made. The results showed that the electric pole diameter of the lens plays main function in the imaging characteristics of the four poles electrostatic doublets lens. The results show that the aberration figures can be enhanced when the electrode diameter of the quadrupole lens is equal to the lens aperture, while the chromatic aberration can be improved by choosing the electrode diameter according to the equation.