Broadband Plasma Relativistic Microwave Source with a Short Pulse Duration

Abstract

This study continues a series of works on creating a broadband plasma microwave sources on the basis of a smooth waveguide. Various methods for creating microwave sources and various methods for feedback uncoupling are considered with the purpose of generating continuous-spectrum microwave radiation. It is shown by numerical simulations that the plasma relativistic oscillator can be transformed into a noise amplifier by changing the parameters of the system. The numerical simulations allow one to determine the operating parameters of the experimental devices that are planned to be created and investigated in the future. It is shown that, when the time of the wave passage along the microwave oscillator exceeds the duration of the relativistic electron beam (REB) pulse, the microwave spectrum is continuous. However, if the wave passage time is much shorter than the REB pulse duration, then a line microwave spectrum will be observed at frequencies at which the oscillator length is a multiple of the half-wave, because microwave generation occurs on the longitudinal types of plasma oscillator modes. The tuning of the average microwave frequency from 3 to 9 GHz is achieved at a power of about 40 MW.