Investigation on 0.5THz Backward Wave Oscillator Based on Two-section Rectangular Gratings

The 0.5THz backward wave oscillator, with Two-section rectangular gratings involving cylindrical electron beam, was developed. The length of the two-section backward-wave oscillator was determined by that of one section structure. The drift part linking the first section and second section, was located according to electron bunch. The output power of backward-wave oscillator is improved by introducing the floating part which can make the electron beam losing more energy and enhance the beam-wave interaction. The length of floating part was optimized by output power with particle-in-cell (PIC) simulations. When the length of floating part is 0.3mm, the maximum output power increases to 2.6W, comparing with that of one section structure (0.3W). Besides, the influences of conductivity, magnetic field, beam voltage and current on the output power are investigated through the CST simulation. The optimum results will be appeared in detailed abstract.