Research On Terahertz Source Based On Smith-Purcell Super Radiant Amplifier

Terahertz(THz)electromagnetic waves generally refer to electromagnetic waves with a frequency between 0.1THz and 10.0THz,and the corresponding wavelength is between 0.03 mm and 3mm.The terahertz wave of this band happens to be between the submillimeter wave and infrared light,so it has excellent properties such as a wide system bandwidth and high penetration,and has important advantages in the fields of biological imaging,material science,communication radar,etc.research value.However,with the public's urgent need for the high frequency and high power of terahertz radiation sources,the reduced size of the structure is difficult to actually process,the sharp increase in electron beam energy,and low efficiency are all problems that scientific researchers need to solve urgently.Therefore,vacuum electronics is a very important source of terahertz radiation.Research on terahertz radiation sources under electric vacuum can greatly improve the application prospects of terahertz technology,and Smith-Purcell super radiation is an excellent source of high-frequency terahertz radiation.way.This article proposes a terahertz source of Smith-Purcell radiation based on the grating structure for the above problems.Discuss the dispersion characteristics of the rectangular grating in detail,and conduct in-depth analysis and research on the characteristics of the SmithPurcell superradiation excited by the electron beam in the periodic structure,so as to design a high-frequency,high-efficiency,high-power terahertz radiation source.The specific work is as follows:1.Theoretically derive the dispersion equation of the rectangular single grating and use the software to draw the corresponding dispersion curve,and discuss the influence of the main parameters of the single grating on its dispersion characteristics.2.The particle simulation software is used to study the THz wave Smith-Purcell superradiation generated by the rectangular single grating excited by the electron beam.According to the dispersion curve,the frequency of the operating point,etc.,the required single grating structure parameters are designed.Finally,when the electron beam energy is 20 keV,a structure that can generate 260 GHz superradiation waves is designed,and when the electron beam energy is 15 ke V,a grating structure that can generate 346 GHz frequency-doubled radiation waves is designed.3.Further derive the dispersion equation of the double-hole grating structure and use the corresponding software to analyze the dispersion curve.Combining the dispersion curve and the frequency of the operating point,a 600 GHz dual-hole grating structure is designed when the electron beam energy is 50 ke V,and it is verified that the structure can greatly reduce the advantages of the starting current density.4.Detailed analysis and in-depth research on the structure and resonance conditions of the three-mirror quasi-optical cavity.On this basis,a model of Smith-Purcell superradiation amplification through three-mirror quasi-optical cavity coupling is proposed,and CST software is used for simulation calculation,which verifies the feasibility of the scheme.