Superradiation Terahertz Smith-Purcell radiation generated from two section gratings with three-dimensional particle-in-cell simulations

A novel method for generating superradiant Terahertz (THz) Smith-Purcell (SP) radiation from a two-section gating is presented in this paper. For analyzing the characteristics of this kind of grating, the three-dimensional (3D) particle-in-cell simulations are employed, the time of start oscillator, saturated power, the electric fields near the two-section grating are analyzed with the help of three-dimensional PIC simulation. On the other hand, the radiation power generated from the two-sections grating and normal one is compared. The results of PIC simulations show that the radiation power can be remarkably enhanced and the time of start oscillation can be reduced by the two-sections grating.