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1.
The results of experimental and theoretical analysis of the dependence of the generation power of a low-voltage vircator, viz., a nonrelativistic electrovacuum device based on a high-intensity electron beam with a virtual cathode, on the values of controlling parameters are considered. The dependences of the generation power on the decelerating potential and on the beam current are analyzed. 相似文献
2.
S. A. Kurkin A. A. Koronovskii A. E. Hramov A. A. Kuraev S. V. Kolosov 《Bulletin of the Russian Academy of Sciences: Physics》2013,77(12):1452-1455
A numerical study of a low-voltage vircator with controlled emissions from a thermocathode is performed for when an external signal effects on the electron beam and modulates the emission. The strong influence of the modulation parameters on characteristics of oscillations of the beam with virtual cathode is noted. It is shown that when the modulation frequency is tuned to the one of harmonics of a virtual cathode’s free oscillations, there is a considerable increase in the power of high-frequency harmonics of the virtual cathode’s free oscillations in the output spectrum. 相似文献
3.
S. A. Kurkin A. A. Koronovskii A. E. Hramov 《Bulletin of the Russian Academy of Sciences: Physics》2013,77(12):1448-1451
A numerical study of the output power characteristics of microwave radiation from a relativistic electron beam (REB) with a virtual cathode in the presence of externally applied longitudinal magnetic field is performed. Typical dependences of the output microwave power of the relativistic vircator system on the external magnetic field strength are obtained, showing a number of local maxima. It is found that the characteristic behavior of the radiation power is determined by the conditions and mechanisms of virtual cathode formation in the presence of external longitudinal magnetic field and a self-magnetic REB field. 相似文献
4.
S. A. Kurkin A. A. Koronovskii A. E. Hramov 《Bulletin of the Russian Academy of Sciences: Physics》2009,73(12):1628-1631
The physical mechanisms leading to the chaotization of the virtual cathode oscillations in a low-voltage vircator system at
an increase in the amplitude of the external inhomogeneous magnetic field created by a ring magnet have been studied within
a two-dimensional numerical model. It has been established that the chaotization of the virtual cathode oscillations in a
strongly inhomogeneous external magnetic field is due to the formation of the secondary electronic structure (electron beam)
in the electron flow resulting from the magnetic trap in the outer layers of the electron beam. 相似文献
5.
采用小信号理论,在考虑到透射、反射束电子不同作用下,分析了虚阴极振荡器产生微波的机制,获得了计算微波主频的方法,讨论了增强束波作用效率的方法,并提出一种新型结构的虚阴极振荡器。该振荡器的阳极后放置了一个谐振腔,谐振腔长度很小,虚阴极不能在其中形成,谐振腔受到反射电子束激励并建立强场,场对入射电子进行调制,同时采用同轴结构引出微波。利用2.5D PIC 程序对新型的结构进行了数值模拟,验证了理论分析的正确性。在入射电子束电子能量为520keV和电子束流12.5kA的条件下,获得微波平均功率为1GW,频率为3.66GHz,平均束波转换效率为15.3%。 相似文献
6.
S. A. Kurkin A. A. Koronovskii A. E. Khramov A. A. Kuraev S. V. Kolosov 《Technical Physics》2013,58(10):1489-1497
A two-dimensional numerical model is used to study the generation of powerful microwave radiation in a vircator with an inhomogeneous magnetic field applied to focus a beam. The characteristics of the external inhomogeneous magnetic field are found to strongly affect the vircator generation characteristics. Mathematical optimization is used to search for the optimum parameters of the magnetic periodic focusing system of the oscillator in order to achieve the maximum power of the output microwave radiation. The dependences of the output vircator power on the characteristics of the external inhomogeneous magnetic field are studied near the optimum control parameters. The physical processes that occur in optimized virtual cathode oscillators are investigated. 相似文献
7.
R. A. Filatov Yu. A. Kalinin A. E. Khramov D. I. Trubetskov 《Radiophysics and Quantum Electronics》2006,49(10):769-778
We numerically simulate the influence of positive ions on characteristics of the microwave oscillations in a nonrelativistic
electron beam with the virtual cathode formed in a decelerating field (low-voltage vircator). A numerical scheme allowing
for ionization of a residual gas by an electron flow is proposed. It is shown that the residual-gas ionization in the operating
chamber of a low-voltage vircator leads to a forcing of the virtual cathode out of the transit gap and to a cutoff of microwave
oscillations. The obtained numerical data are confirmed by an experimental study using a low-voltage vircator model.
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Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 49, No. 10, pp. 853–863, October 2006. 相似文献
8.
基于虚阴极微波发生器的原理,设计一种特殊的高阻抗、低束流Vircator的实验装置,并结合理论研究对该实验系统的各种参量进行了数值计算与分析,实验测试结果与理论设计计算吻合,在3cm频段获得的输出功率≥20MW。 相似文献
9.
N. S. Frolov A. A. Koronovskii A. E. Khramov 《Bulletin of the Russian Academy of Sciences: Physics》2011,75(12):1592-1595
The output power of generation in a chain of unidirectionally coupled low-voltage vircators upon variation in controlling
parameters of a system is studied. It is shown that at a certain set of controlling parameters, the output power of the generator
chain grows sharply. Physical processes occurring in the system are analyzed by plotting space-time diagrams of the motion
of charged particles of the electron flow with a virtual cathode. The obtained results are in good agreement with the data
from a previous experimental study on signal amplification in a low-voltage vircator. 相似文献
10.
N. S. Frolov A. A. Koronovskii A. E. Hramov Yu. A. Kalinin A. V. Starodubov 《Bulletin of the Russian Academy of Sciences: Physics》2012,76(12):1329-1332
Analytical, numerical, and experimental investigations of the output power of a generator are performed on a virtual cathode under the effect of an external harmonic signal. It is shown theoretically that an increase in the power of the external effect leads to an increase in the output power of a nonautonomous oscillator. The results from our theoretical analysis are in good agreement with the results from a pilot study. 相似文献
11.
Kraft R. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1993,21(6):739-742
A resonant cavity vircator (virtual cathode oscillator) driven by an electron beam emitted from a broad-area thermionic cathode is tested. Narrow-bandwidth (1.0 MHz at the -3 dB level) excitation of the TM023 mode of a cylindrical resonant cavity is observed at a frequency of 986 MHz with a pulselength of 1.2 μs. The single-cavity-mode excitation is attributed to the constant-voltage and -current electron beam emitted from the thermionic cathode 相似文献
12.
The nonlinear dynamics of an electron beam with a virtual cathode in a transit-current vircator system is numerically studied.
The existence of complex modes, including chaotic ones, is shown. The physical processes in the electron beam are examined.
It is found that the chaotic dynamics in an electron beam with a virtual cathode is due to the nonlinear interaction between
the structures organized in it.
“College,” State Education and Scientific Center of the State University, Saratov, Russia. Translated from Izvestiya Vysshikh
Uchebnykh Zavedenii, Radiofizika, Vol. 41, No. 9, pp. 1137–1146, September, 1998. 相似文献
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14.
R. A. Filatov A. A. Koronovskii S. A. Kurkin A. E. Hramov 《Bulletin of the Russian Academy of Sciences: Physics》2012,76(12):1336-1338
The physical processes in a vircator without an external magnetic field and with a drift space filled by neutral gas are studied. Three typical dynamic regimes are found: (1) the suppression of virtual cathode oscillations, (2) pulse generation, in which the suppression and resumption of virtual cathode oscillations are observed, and (3) continuous virtual cathode generation. The frequency dynamics of the vircator’s output radiation is investigated for the last case, and it is shown that the generation frequency of the vircator can rise when the gas pressure exceeds a certain critical value. 相似文献
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16.
Super-reltron theory and experiments 总被引:1,自引:0,他引:1
Miller R.B. McCullough W.F. Lancaster K.T. Muehlenweg C.A. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1992,20(3):332-343
A highly efficient, high-power microwave tube called super-reltron is reported. The authors have achieved operation at >400 MW with ~50% efficiency at 1 GHz, and 250 MW with 40% efficiency at 3 GHz. The RF pulse durations are typically a few hundred nanoseconds. These compact lightweight tubes do not require an external magnetic field. The RF output coupling is straightforward and delivers the power directly via the fundamental TE10 wave in a rectangular waveguide without a mode converter. The key features of the tube include (i) generation of a well-modulated electron beam by periodic virtual cathode formation, (ii) postacceleration of the modulated beam to reduce the relative electron energy spread, and (iii) a multicavity output section that efficiently extracts power without RF breakdown. Various theoretical aspects of the device are discussed and the experimental results are summarized 相似文献
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18.
In this Letter the results of theoretical investigations of the chaotic microwave oscillator based on the electron beam with a virtual cathode are presented. Nonlinear non-stationary processes in these electron systems are studied by means of numerical analysis of 2.5D model. It was discovered that the non-uniform external magnetic field value controls the dynamical regime of oscillations in the virtual cathode oscillator. The processes of the chaotization of output microwave radiation are described and interpreted from the point of view of the formation and interaction of electron structures (bunches) in the electron beams. The numerical results have shown that the investigated electron system with virtual cathode could be considered as a promising controlled source of wideband chaotic oscillations in the microwave range. 相似文献
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20.
E. N. Egorov Yu. A. Kalinin A. A. Koronovsky D. I. Trubetskov A. E. Khramov 《Radiophysics and Quantum Electronics》2006,49(10):760-768
We present the results of studies within the framework of a two-dimensional numerical model of nonlinear nonstationary processes
in a nonrelativistic electron beam in the mode of formation of a virtual cathode in the decelerating field without focusing
of the electrons by a magnetic field (low-voltage vircator). The results of numerical simulation were qualitatively confirmed
by the experiment.
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Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 49, No. 10, pp. 843–852, October 2006. 相似文献