A novel X-band rectangular industrial free electron maser

At the University of Liverpool, we are developing prototype free electron masers (FEMs) that are compact, powerful and efficient for industrial applications. The design, set-up and experimental result of a novel X-band rectangular waveguide industrial free electron maser are presented in this paper. Our initial device operates at 10 GHz and employs two rectangular waveguide cavities (one for velocity modulation and the other for energy extraction). The electron beam used in this experiment is produced by thermionic electron gun which operates at 3 kV and up to 50 muA. The nominal beam diameter is 1 mm passing across the X-band cavity resonators. The resonant cavity consists of a thin gap section of height 1.5 mm which reduces the beam energy required for beam wave interaction. The effect of the phase difference between the input and output cavity on the output power is reported.