An oversized Ku-band Cerenkov oscillator with pure TM01 mode output

Abstract

An oversized Ku-band Cerenkov oscillator with pure TM01 mode output is proposed. By utilizing a separated slow-wave structure (SSWS), the resonant characteristic of the operating mode is preserved, whereas the resonant characteristics of the high order electromagnetic modes are destroyed. As a result, only the expected mode can be stimulated, and undesired beam–wave interactions are suppressed effectively. In terms of an oversized Cerenkov oscillator, the usage of SSWS shows great potential for obtaining pure operating mode output. By utilizing particle-in-cell simulation, microwaves with an output power of 4.5 GW and frequency of 14.1 GHz are obtained, when the beam voltage is 0.9 MeV, and the beam current is 12.9 kA. The percentage of the operating mode is up to 99.5% and exceeds 99% in a wide range of the beam voltage.