Multiple criteria optimization of electrostatic electron lenses using multiobjective genetic algorithms

The design of an electrostatic electron optical system with five electrodes and two objective functions is optimized using multiobjective genetic algorithms (MOGAs) optimization. considered are minimum probe size the primary beam in a fixed image plane maximum secondary detection efficiency at in-lens detector plane. time-consuming step calculation potential. There methods to do this. first COMSOL (finite element method) second second-order electrode method (SOEM). former makes optimization process very slow but accurate, latter it fast less accurate. A fully automated strategy presented, where SOEM-based MOGA provides input systems for COMSOL-based MOGA. This boosts reduces times by least ∼10 times, from several days few hours. typical has 11.9 nm 80%. new can be implemented lens one or more multiple free variables as efficient, technique.