Filled With Plasma Flat-panel Period Grating And Terahertz Radiation Research

In order to obtain higher output power and higher efficiency, the plasma is introduced into the vacuum electronic devices. With more experimental studies about the devices loaded with plasma, it is found that the cooperation efficiency and the operation frequency can be effectively enhanced.The study about the plasma-loaded Terahertz(THz) radiation devices get attention of more and more scientists.In this dissertation, with the theoretical analysis and the PIC simulation, the plasma-loaded planar periodic grating with and without coverboard are studied, respectively. Simultaneity, the influence on the output power of the plasma-loaded planar periodic grating by various working parameters are also studied. The main works are the following:1. The dispersion relation of planar periodic grating waveguide loaded plasma is derived by mode-matching method, and the influence of different parameters of the grating, the electron beam and the plasma on the grating's dispersion relation and the growth rate are all investigated using numerical calculation.2. With the help of PIC simulation method, the influence of the different parameter of the grating and the electron beam on output power and the frequency of the plasma-loaded planar periodic grating without coverboard are studied. Results show that the frequency increase with the decreasing of groove's width thickness and the thickness of electron beam. Otherwise, the output power decreases and the output frequency slightly falls with the increasing of the distance between the electron beam and the grating.3. The radiation power and the frequency of plasma loaded planar periodic grating with coverboard are investigated. The results show that the distance between grating and coverboard in some case can improve the output power. The output power can be enhanced to a peak with the increasing magnetic field. However, it reduces at certain magnetic field, and increasing of the output power becomes slow after it. After loaded with plasma, the output power increases more than that without plasma, and the output power arrived at a peak rate at certain plasma density. The output power enhances by increasing the atomic weight of loaded plasma.