Field computation techniques in electron optics

The authors describe the software for the computer-aided design of electron and ion optical systems, with special emphasis on field computation in devices with diverse physical structures. These include electron guns, magnetic and electrostatic lenses and deflectors for electron-beam lithography and inspection systems, wide-angle lenses and deflectors for cathode-ray tubes, components with constructional errors, multiple lenses, and structures with fully three-dimensional field distributions. The computed fields are accurate enough for reliable evaluation of the optical properties, including the aberrations