ISSN 0869-6632 (Print)
ISSN 2542-1905 (Online)


Study of gyrotron synchronization by an external harmonic signal based on a modified quasi-linear theory

Topic. The paper is devoted to the study of synchronization of a gyrotron by an external harmonic signal. A theoretical study of gyrotron synchronization processes by means of a computational experiment based on certain traditional models of microwave electronics does not provide a complete description of the synchronization pattern. Therefore, the goal of the paper is to develop a modified quasi-linear model based on an approximation of the electron susceptibility by rational functions. Methods.

Zones of stable single-mode generation in overmoded gyrotrons

During numerical simulations of the model of gyrotron with fixed field-structure, zones of stable single-mode generation of the work mode are analyzed on the plane of parameters «magnetic field – beam current». It is shown that area and sizes of the zones are strongly dependent on the spectral density of eigen-frequencies of the resonator and on number of considered parasit modes.

Effect of delayed reflection from the remote load on mode competition in а gyrotron

Effect of reflection from the remote load on the mode competition in a two-mode electronic maser is considered. A system of quasilinear equations for slowly varying amplitudes of the modes with cubic nonlinearity where the effect of reflections is taken into account by time delayed terms is analyzed. The most typical case of competition of two modes with close frequencies at the centre of generation zone is studied in detail.

The investigation of subterahertz gyrotron for dnp spectroscopy in the IAP RAS

The paper presents the results of research is carried out in the Institute of Applied Physics and is aimed at creating a CW submillimeter gyrotrons with an output power of several tens of watts. Results of experiments on the 258 GHz gyrotron at the second harmonic of the gyrofrequency are presented. In the course of experiments maximum output power of 200 W and the relative stability of the output frequency at 5 · 10−6 for the hours-long continuous operation of the gyrotron were achieved.

Effect of reflection from remote load on mode competition in gyrotron with quasi­-optical mode convertor

In a gyrotron with quasi-optical mode convertor, apart from the fundamental mode, excitation of a mode with opposite azimuthal rotation of the field occurs due to the wave reflected from the remote load. Interaction of the two oppositely rotating modes is investigated by using the quasi-linear equation for slowly varying amplitudes. The developed theory allows explanation of the experimental results where periodic modulation of the transverse structure of gyrotron radiation partially reflected from a remote oscillating membrane was observed.

Two-wave gyrotron on whispering gallery modes at the irregular waveguide

The three-dimensional excitation equations for the longitudinal-irregular circular waveguides with finite conductions of the walls by electron beams in completed form for self-consistent models of gyrotrons, peniotrons, relativistic TWT and BWO had been derived. The possibilities of improving the efficiency of millimeter-wave gyrotron with multimode interaction fields of whispering gallery waves and a relativistic helical electron beam were consider. It is shown that two-mode gyrotron, compared with single-mode allows you to raise the efficiency from 40 to 45%.

Development of methods of gyrotrons electron-optics systems with axial symmetry distortion

The simulation technique of helical beam formation system of gyrotrons with typical axial symmetry distortion is presented. The simulation of the second harmonic magnetron-injection gun for 260 GHz band gyrotron with 0.5 mm beam axis displacement was made. It was shown that displacement of axis beam has a significant effect upon the angular distribution of pitch-factor.

Gyrotron frequency stabilization under the influence of external monochromatic signal or wave reflected from the load: review

We study gyrotron frequency locking by the external monochromatic wave and stabilization of gyrotron frequency by the wave reflected from the non-resonant or resonant load. Although in the last decades influence of the external monochromatic signal and the reflected wave at the gyrotron operation was studied in a number of publications, concrete schemes of gyrotron frequency stabilization weren’t discussed.

Study of synchronization in the system of two delay-coupled gyrotrons using a modified quasilinear model

Topic. The paper is devoted to the study of mutual synchronization of two gyrotrons coupled with delay. As a rule, a theoretical study of synchronization of gyrotrons and other microwave oscillators is usually carried out by numerical simulations using certain well-established models of microwave electronics. Using this approach, it is difficult to provide a fairly complete synchronization pattern, using methods and ideas of nonlinear dynamics. Aim.