Simulation of rapid startup in microwave magnetrons with azimuthally varying axial magnetic fields

Abstract

A method is proposed whereby the startup of a magnetron may be hastened. For a N-cavity magnetron operating in the pi mode, the formation of the N/2 electron spokes is much more rapid when an azimuthally varying axial magnetic field of N/2 periodicity is employed. Electromagnetic particle-in-cell code simulations are presented that show electron prebunching by the azimuthally varying axial magnetic field, long before the pi mode is excited.