Study the Spent Electron Beams Based Low-Voltage Vircator

Abstract

It is well known that in such amplifying microwave devices as a traveling-wave tubes (TWT) and a klystrons, the electron beam at the exit from the interaction space has a significant electron velocity spread and a electron beam residual grouping1. The use of such a spent electron beam seems promising for the implementation of sources of broadband noise-like microwave oscillations of an average power level (10–100 W). We propose an original scheme of a hybrid device consisting of a traveling wave tube (TWT) and a low-voltage vircator. A hybrid microwave device consists of a TWT, a drift pipe located immediately after the output of energy (low-voltage vircator), with measuring probe and a collector, the potential of which can vary widely. The results of an experimental study of the parameters of broadband noise-like generation of a low-voltage vircator using a spent electron beam at the exit from the interaction space of a TWT were obtained. The results of the study of the energy and spectral characteristics of the proposed device are shown. Experimental studies were carried out with help of a collapsible vacuum installation in a pulsed mode (pulse duration τ = 50 μs, duty cycle Q = 1000)2. All elements of the proposed device under study were placed in the same evacuation research chamber of a collapsible vacuum unit. The calculation of the efficiency of the investigated device was carried out. The main parameters of the spent electron beam based oscillator are as follows: accelerating voltage 4.2 kV, beam current 130 mA, output integrated power 60 W, electronic efficiency 11%, operating frequency band 1–3 GHz. Thus, the carried-out studies have shown that the use of a spent electron beam with a large electron spread in longitudinal velocities leads to the generation of broadband noise-like oscillations. Also, it was shown that it is possible to implement various multifunctional systems in one hybrid device: a mono signal amplifier based on a TWT and an oscillator of middle power noise-like signals.