Title :
Optimization of electron lens shape giving minimum spherical aberration coefficient
Author :
Kato, M. ; Tsuno, K.
Author_Institution :
Jeol Ltd., Tokyo, Japan
fDate :
3/1/1990 12:00:00 AM
Abstract :
A novel computer-aided optimizing procedure has been developed to obtain the geometry of the magnetic electron lens that give the minimum spherical aberration coefficient Cs. The minimization of Cs is done by a simplex method in which Cs is regarded as a function of up to 11 parameters characterizing the lens geometry. In this process, Cs and other optical properties of lenses are evaluated using a high-speed FEM (finite-element method) with automatic mesh generation. The optimization procedure was applied to the design of an objective lens for a 400 kV transmission electron microscope
Keywords :
CAD; aberrations; electron lenses; finite element analysis; magnetic lenses; transmission electron microscopes; 400 kV; automatic mesh generation; computer-aided optimizing procedure; high-speed FEM; lens geometry; magnetic electron lens; minimum spherical aberration coefficient; objective lens; optical properties; transmission electron microscope; Computational geometry; Design optimization; Electron optics; Finite element methods; Geometrical optics; High speed optical techniques; Lenses; Mesh generation; Minimization methods; Shape;
Journal_Title :
Magnetics, IEEE Transactions on
