UDC 621.385We simulate collective processes in an electron space charge trapped between the cathode and the magnetic mirror in gyrotron-type systems using the particle-in-cell method. Threshold conditions of excitation and frequency-amplitude characteristics of low-frequency oscillations connected with the development of an instability in a space charge in the trap are determined using a gyrotron with an output power of 100 kW and a radiation wavelength of 4 mm as an example. The mechanism of the instability development in an ensemble of anharmonic electron oscillators is proposed and used to analyze the method of oscillation suppression based on varying the magnetic-field distribution in the region of the beam compression. The influence of low-frequency oscillations on the parameters of the electron beam entering the cavity is studied. The obtained calculation data are compared with the results of the experiments studying the parameters of low-frequency collective processes in gyrotrons.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.