Calculation of the Spherical and Chromatic Aberrations for Electrostatic Lenses Using Genetic Algorithm

Abstract

Optical aberrations degrade the detecting performance in electron spectrometers. It is very difficult to calculate optical aberration parameters for complex electrostatic lens systems. In order to overcome this difficulty, the genetic algorithm method as a solution is introduced in this study. GAs are an intuitive research method based on the principle of generating new sequences of chromosomes in order to solve complex ordered problems. These algorithms target the global optimization of mathematical functions. This study uses a genetic algorithm to demonstrate the results of optimum aberration coefficients as a function of magnification for three-element electrostatic cylinder lenses. This algorithm is used to search for high-performance values. Different mutation and crossover probability values and also different selection and crossover types are tested. The optimum solution is obtained with a mutation rate of 0.01 and uniform crossover with a rate of 0.7. The proposed approach ensures the optimal solution for the aberration problems of the electrostatic lenses.