V.A. Senchurov - Ph. D. (Eng.), Associate Professor, Department «Electronic Instruments and Devices», Yuri Gagarin State Technical University of Saratov E-mail: senchurov_v86@mail.ru V.Yu. Muchkaev - Ph. D. (Eng.), Associate Professor, Department «Electronic Instruments and Devices», Yuri Gagarin State Technical University of Saratov E-mail: muchkaev_vadim@mail.ru

Electrodynamic characteristics of double-gap resonators with straddled into two beams floating-drift channels were numerically analyzed. In these resonators, besides the fundamental operating mode, it is excited the broad spectrum of superior type of oscillations, which also can interact with electron flow. Typically, the superior types of oscillations are considered as spurious and the construction of resonator matches so that they could not be excited in the operating mode. However, if one or several (n) superior types of oscillations can be tuned to frequencies fn multiple to the frequency of major signal f1, then this kind of operating regime can be used either for creating the modulating voltage on resonator gaps, the form of which is close to saw-shape, or for multiplying the frequency. The most researched constructions of resonance systems where in capacity of superior type with multiple frequency one chooses the cophased (2π-type) type of oscillations with multiplicity f2/f1 = 2. These paper covers the availability of frequency multiplicity with higher types of oscillations with correlation fn/f1 = 3. Primarily, the typical constructions of double-gap cavities with central location of floating-drift channels were chosen for researches. However, in this construction the longitudinal component of superior types of oscillations, frequencies of which are similar to 3f1, changes the character along the barrel diameter with floating-drift channels. Therefore, the construction of double-gap cavity, in which floating-drift channels are separated into two bunches, was studied. Each of them consists of five floating-drift cavities. It is necessary to say that bunches in principle can be changed into two ribbon beams. The analyses of numerical computations showed that there is one mode in this resonator - f16, the frequency of which is close to a value of 3f1. The major type of oscillations has antiphase voltages on gaps (π type) and superior mode has cophased voltages (2π -type). Space distribution of longitudinal component of electric field of major and superior type of oscillations in lateral to bunch movement flatness was calculated in this paper. In addition, the frequency of major and superior types of oscillations was tuned at the expense of the change of geometrical parameters of P shaped gap, which electromagnetically connects the resonance cavities of researched double-gap cavity. It was shown that in double-gap cavity with straddling floating-drift channels on two bunches, one can obtain the relation f16/f1 = 3 with the frequency f1 ≈ 36 GHz and f16 ≈ 108 GHz. Such regime can be used for creation frequency multipliers and thereby it is possible to get the gen-eration in terahertz frequency range. Obtained during numerical computations distributions of electromagnetic fields permitted to cal-culate electrodynamic characteristics of examined resonator. The value of characteristic impedance of 16 th types of oscillations has rather high nonuniformity, the highest value could be obtained in extreme floating-drift channels with the minimum value in the central channel, unlike the major type of oscillations. The interaction efficiency factor on the 16 th type of oscillations in the range of accelerating voltage from 1 to 20 kV does not increase the value 0, 32. This paper demonstrates also, that for the major type of oscillations the interaction efficiency in maximum values of interaction efficiency on the 16th type also obtains the value close to maximum. The calculation of the dependence of relative electron conduction Ge/G0 on the accelerating voltage V0 for the major (curves 1) and 16 th (curves 2) types of oscillations shows that for the multiplication regime of frequencies the most consistent is the accelerating voltage ranging from 8,7 to 10,1 kV, that is the region where Ge/G0 > 0 for the major type of oscillations and Ge/G0 < 0 for the highest types.

 

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