Results of a novel X-band pre-bunched free electron maser

Abstract

We have developed a prototype free electron maser that is compact and powerful. The design, set-up and results of a novel X-band rectangular waveguide pre-bunched free electron maser (PFEM) are presented in this paper. Our device operates at 10 GHz, with 10 mWatt seeding input power 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 Thoria coated Iridium filament which can operate at 3 kV and up to 5 mA beam current. The effect of the aperture on the power leaking out of the waveguide is also analyzed. The TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> mode propagation of the EM standing wave is used to pre-bunch the electron beams in the input cavity. The bunched electron beams are in the same phase as they interact with the TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> mode propagation of the EM standing wave in the output cavity.