Virpertron: A novel approach for a virtual cathode oscillator design

In this paper, we propose a novel approach for the design of a virtual cathode oscillator. As a new concept, we suggest a microwave system containing an annular relativistic electron beam travelling through the drift space with dielectric inserts characterized by different values of permittivity. In this case, a virtual cathode which is the source of powerful electromagnetic oscillations forms at the junction of different dielectric materials. According to the mechanism of virtual cathode formation, we have called this device as a virpertron. We have carried out a detailed numerical investigation of virtual cathode formation features in this system via 3D electromagnetic PIC-simulation using CST Particle Studio. We have also studied the spectral properties of the microwave radiation generated by the virpertron.