Work

The work is devoted to theoretical and experimental investigation of transport conditions and bunching of electron beams in weakly inhomogeneous magnetic fields of the focusing magnetic systems for BWO klinotron and CRM oscillators, as well as the characteristics of oscillations of such generators with non-traditional electrodynamic systems. The influence of the inhomogeneity of the magnetic field on the excitation of oscillations in the submillimeter BWO klinotrons has been studied. The optimal distribution of the magnetic field for BWO klinotrons at 300 - 400 GHz range was found. The properties of the natural oscillations of the resonator BWO klinotrons with dual and multi-stage systems were observed. It was shown that in the system of multi-comb - cavity the space-surface oscillations are excited. This provides a high resistance connection and good quality factor. Millimeter and submillimeter generators with such systems were developed and their properties are studied experimentally. The methods of increasing the stability of the oscillation frequency have been analyzed. The development of the basic units of high-voltage power supply with improved stability of the output voltage for submillimeter BWO generators was carried out. The electromagnetic radiation in CRM with a cylindrical cavity and the low voltage HEB with accelerating voltage of 2.2 kV was excited. Also for the first time the presence of an additional electron bunching mechanism in weakly inhomogeneous magnetic field regions was shown. The electron-optical system forming the sheet HEB with a high degree of electrons rotational energy was numerically simulated. The obtained sheet HEBs have a pitch - factor value higher than one with an accelerating voltage and beam current of 12 kV / 1 A and 5 kV / 300 mA. The sheet HEB for 5 kV was formed and experimentally investigated. The measured electron velocity spread is acceptable for efficient excitation of oscillations in two-mirror cavity of such beam and results are in a good agreement with the results of numerical simulations. Also the numerical simulations show the possibility of stable single-frequency generation as a result of wave-particle interaction of sheet HEBs of 5 kV and 12 kV with RF-field of the cavity that consists of two mirrors.