Comparison of electrostatic and time dependent simulation codes for modeling a pulsed power gun

A comparison of two codes suitable for electron gun simulation was performed. Good agreement in transverse phase space values was found between the electrostatic code (PBGUNS) and the time dependent code (MAFIA) for a variety of pulse durations, even for pulse durations short compared to the electron transit time of the accelerating region. To obtain values for the longitudinal energy spread and the variation of the transverse phase space across the bunch, it was necessary to use MAFIA. The electrostatic codes have an advantage in terms of required computational resources and run time, and are therefore a good choice for modeling jobs in which the longitudinal energy spread is unimportant