Evaluation of mode competition in the radial acceletron

Summary form only given, as follows. Simulations of the radial acceletron are presented. The radial acceletron is a low-impedance high power microwave (HPM) source which is compact, relatively low voltage (250 kV), and requires no external magnetic field. Microwave radiation is produced through bunching of emitted electrons caused by the radial transit-time effect and interaction with cavity modes in the diode region of the device. Simulations are performed using the parallel 3D particle-in-cell (PIC) code, ICEPIC. The time required to reach saturation is very long in this device (>100 nsec). The existence of competing non-axisymmetric modes could prevent efficient operation. The purpose of these simulations is to determine whether such modes are likely to exist.