Simulation of Smith-Purcell radiation in an open resonator with inverse trapezoid grating

The Smith-Purcell radiation in an open resonator, with an inverse trapezoid shaped grating, is presented in this paper by a two dimensional particle-in-cell (PIC) simulation. The simulation model supposes that a mono-energetic electron beam passes over the cylindrical diffraction grating with a strong axial magnetic field constraining the electrons to longitudinal motion. The simulation results indicate that the cavity with inverse trapezoid shaped groove grating has higher output power and lower operating frequency than the one with rectangle shaped groove grating, when the other geometric dimensions of this structure are fixed.