Computer aided design and analysis of imaging energy filters with inhomogeneous bending magnets

Software has been written to analyze and design magnetic imaging energy fil ters. The filters can be composed of any number of bending magnets of homog eneous or inhomogeneous type. The sharp cut-off fringing field approximatio n is used initially to evaluate quickly many possible designs. Promising de signs are then analyzed taking the real fringing fields at the edges of the bending magnets into account, including the full three-dimensional field d istributions in conical bending magnets. Graphical postprocessing software displays the optical properties in the energy selection plane and the image plane in the form of spot diagrams and current density contours. (C) 2000 American Vacuum Society. [S0734-211X(00)09506-8].