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This paper presents a simulation of Smith-Purcell (SP) radiation from dielectric loaded grating (DLG) at terahertz frequencies, which is performed by using a two-dimensional (2D) particle-in-cell (PIC) code. The simulation supposes a continuous electron beam passing over a DLG and metal grating, respectively. The results show that compared with metal grating, the usage of DLG can enhance the radiation...
In this paper, a simulation on the evanescent wave of Smith-Purcell (SP) radiation from dielectric loaded grating (DLG) is presented at terahertz frequencies. The evanescent wave provides feedback to bunch the electron beam, which is the basis of oscillator operation of SP free-electron laser (FEL). The results obtained from particle-in-cell (PIC) code are compared with metal grating, which show that...
Enhance the efficiency of beam-wave interaction is an important problem in the design of folded waveguide traveling-wave tube (TWT) amplifier. A dielectric-loaded tapered folded waveguides was studied, whose equivalent circuit analysis is mainly introduced in this paper.
In this paper, a dielectric loaded grating is proposed to enhance the Smith-Purcell (SP) radiation at terahertz frequencies. By using two-dimensional particleincell (PIC) code, the radiation power of dielectric loaded grating with different currents is simulated. The results show that compared with the metal grating, the dielectric loaded grating can decrease the threshold current and improve the...
A novel type of slow-wave structure for Smith-Purcell device called dielectric loaded metal grating, is proposed in this article. The three-dimensional (3D) analytical theory for the “hot” dispersion relation is derived using the field matched method and the results accord well with the simulation data performed by using 3D particle-in-cell (PIC) code.
In this paper, with the help of a two-dimensional (2D) particle-in-cell (PIC) code, a simulation of Smith-Purcell (SP) radiation from the dielectric loaded grating is performed in the terahertz regime. The results show that the SP radiation frequency is in good agreement with the theoretical curve. Comparing with the general grating, the usage of dielectric loaded grating enhances the evanescent wave,...
This paper presents the analysis and design of the pill box input and output windows for THz traveling-wave tube (TWT) amplifier. Both the theoretical mechanism and simulation results are analyzed. The simulation results clearly show a pass band 14 GHz of the window as desired frequency. The results can provide a foundation on the fabricating of THz TWT amplifier.
A 3-D model of the dielectric-loaded rectangular Cerenkov maser for the beam-wave interaction is proposed. The hybrid-mode dispersion equation is derived with the Borgnis potential functions by using the field-matching method. Moreover, its approximate solution is obtained under the assumption of dilute beam. Through numerical calculations, the effect of the dielectric layer thickness, bean thickness...
Ferromagnetic Co0.5Cu0.5Fe2O4 and ferroelectric Ba0.8Sr0.2TiO3 composite ceramics, xCo0.5Cu0.5Fe2O4 + (1-x)Ba0.8Sr0.2TiO3 for x = 0.15, 0.3 and 0.45, were prepared by a conventional solid-state reaction method. The crystalline phases of the sintered samples were studied by the X-ray diffraction technique. Scanning electron microscopy (SEM) micrographs were taken to understand the microstructure of...
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