Crossed-field guns analyzed on a deformable mesh

The principles of a method for the solution of electron optics problems in crossed electric and magnetic fields are described in this paper. The numerical procedure makes possible design and evaluation of crossed-field guns and focusing systems with a high degree of accuracy and resolution. Unlike other procedures, the space within the problem boundaries is filled with a computer-generated network of irregular triangles resembling a stretched fishnet on which Poisson´s equation is solved. A novel approach is used in the near-cathode region leading to a substantial improvement in the accuracy of results in general.