Study of a Dual-Sheet Beam Electron Optic System

In comparison to single-sheet electron beam devices, the output power of multiple-sheet electron beam devices is hopeful to be significantly enhanced due to the increased beam current. One of the most important issues restricting the development of multiple-sheet electron beam devices is the generation and stable transmission of multiple-sheet electron beams. In this article, the design of two dual-sheet-beam electron optic systems (EOSs) with significant features of long transmission distance and high beam current density is presented. Additionally, both of them have achieved a high compression factor and a large aspect ratio. To verify the design, a uniform permanent magnetic focusing structure was fabricated and measured, showing that it could provide an axial magnetic field of ~0.4 T. The designed EOS is applied in a dual-sheet electron beam backward wave oscillator (BWO) and simulation results of the entire BWO show that it is capable of generating an output power of >200 W over a wide bandwidth of 15 GHz (218–233 GHz).