Digital computer simulation of axisymmetric electron beams and guns of any energy

SPEED, a program for the simulation of relativistic (or non-relativistic) electron guns with either space-charge limited (Childs' Law), field emitted (Fowler-Nordheim) or specified injection emitters will be described and demonstrated with several examples. The program can be fully relativistic with induced and applied magnetic fields and crossing trajectories. Basic relaxation techniques are employed on a rectangular array of squares to keep the program small efficient, permitting large arrays for accurate and/or elaborate simulations. Smooth electrodes are created by extending fields into electrodes, which are described by quadratic equations. It is written in FORTRAN 77 employing Calcomp-Versatec type plotting routines and can be run on virtually any computer from high end PC's (with DOS Extenders) to Cray's with only minor modifications. Excellent agreement has been obtained with both theoretical and experimental results