A Broadband Coherent Diffraction Radiation THz Source Based on CTFEL Electron Beam Bunches

Abstract

Coherent Different Radiation (CDR) produced by ultrashort electron beam can be in THz region and has the characteristics of broadband, high peak power, ultrashort and tunable frequency. In this paper, a broadband CDR THz source based on CAEP FEL-THz(CTFEL) electron beam bunches is proposed. With theoretical analysis, numerical calculation and Particle-In-Cell (PIC) simulation, this THz source is proved to be pico to sub-pico second long, and with $100\mathrm{GHz}\sim 400\mathrm{GHz}$ tunable center frequency. The cut-off frequency of is between 1THz to 2THz, the peak power is in 10kW region and the average power can be a few Watts. Furthermore, the THz power is proportional to the square of the electron current. This CDR THz source will be a significant by-product of CTFEL facility and has great development potential.