Optimization of the Double-Gap Vircator with Electromagnetic Feedback in CST Particle Studio

Abstract

The report is devoted to the results of the numerical study and optimization of the double-gap vircator with electromagnetic feedback in CST Particle Studio. The optimal geometrical parameters of this generator when it demonstrates the maximal efficiency were defined for the different working frequencies. The dependencies of the double-gap vircator efficiency on the geometrical parameters were analyzed in the optimal region. The physical processes occuring in the optimized generator were investigated.

Investigation of beam-plasma instability in charged plasma in the absence of ions

“…The simultaneous coexistence of two instabilities in a REB resulting in formation of squeezed state and beam-plasma instability leads to the complex beam dynamics in the system that may be efficiently analyzed mainly with the help of the numerical methods based on the solving of the self-consistent system of Maxwell equations and motion equations of charged particles. For that reason, the three-dimensional fully electromagnetic selfconsistent CST Particle Studio package, which has worked well in the simulation of different beam instabilities and high-power electron devices, [35][36][37][38][39][40][41][42] is used in our work for the accurate numerical investigations of physical processes in the relativistic two-section vircator model.…”

High-power microwave amplifier based on overcritical relativistic electron beam without external magnetic field

“…The similar model was used earlier for the simulations of the aforementioned double-gap virtode 27 that have shown a good agreement with the experimental studies. 31 The parameters of the considered VCA scheme with a REB were chosen in the process of its optimization as follows: the cathode radius-49 mm, the electron gun radius-54 mm, the distance (along the y-axis) between the gun center and the system bottom-227 mm, the distance (along the z-axis) between the cathode and the anode grids-21.5 mm, the resonator width (along the x-axis)-140 mm, the height (along the y-axis) of the first gap-347 mm, that corresponds to h 1 ¼ 120 mm, the distance between the anode grid and the second grid-30 mm, the distance between the second grid and the system end-119 mm, the position of the output waveguide along the y-axis relative to the system bottom-494 mm, the position of the input coaxial waveguide along the y-axis relative to the system bottom-21 mm, the inner and the outer radii of the input waveguide-1 mm and 5 mm, and the length of the part of the input waveguide inner core inside the first gap-28 mm. The important parameter here is the position of the input waveguide that was defined from the conditions of the minimization of the signal reflected back to the input waveguide and the maximization of the interaction efficiency of the electron beam with the input signal that provide a maximal amplification efficiency.…”