The Experts below are selected from a list of 111552 Experts worldwide ranked by ideXlab platform
Alexey A Koronovskii - One of the best experts on this subject based on the ideXlab platform.
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high power microwave amplifier based on overcritical relativistic electron beam without External Magnetic Field
Applied Physics Letters, 2015Co-Authors: S A Kurkin, Alexey A Koronovskii, Nikita S Frolov, A O Rak, A A Kuraev, A E HramovAbstract:The high-power scheme for the amplification of powerful microwave signals based on the overcritical electron beam with a virtual cathode (virtual cathode amplifier) has been proposed and investigated numerically. General output characteristics of the virtual cathode amplifier including the dependencies of the power gain on the input signal frequency and amplitude have been obtained and analyzed. The possibility of the geometrical working frequency tuning over the range about 8%–10% has been shown. The obtained results demonstrate that the proposed virtual cathode amplifier scheme may be considered as the perspective high-power microwave amplifier with gain up to 18 dB, and with the following important advantages: the absence of External Magnetic Field, the simplicity of construction, the possibility of geometrical frequency tuning, and the amplification of relatively powerful microwave signals.
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microwave radiation power of relativistic electron beam with virtual cathode in the External Magnetic Field
Applied Physics Letters, 2013Co-Authors: S A Kurkin, A E Hramov, Alexey A KoronovskiiAbstract:The study of the output power of the electroMagnetic radiation of the relativistic electron beam (REB) with virtual cathode in the presence of External Magnetic Field has been found out. The typical dependencies of the output microwave power of the vircator versus External Magnetic Field have been analyzed by means of 3D electroMagnetic simulation. It has been shown that the power of vircator demonstrates several maxima with External Magnetic Field growth. The characteristic features of the power behavior are determined by the conditions of the virtual cathode formation in the presence of the External transversal Magnetic Field and the REB self-Magnetic Fields.
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effect of External Magnetic Field on critical current for the onset of virtual cathode oscillations in relativistic electron beams
Physics Letters A, 2008Co-Authors: A E Hramov, Alexey A Koronovskii, Mikhail Morozov, Alexander MushtakovAbstract:In this Letter we research the space charge limiting current value at which the oscillating virtual cathode is formed in the relativistic electron beam as a function of the External Magnetic Field guiding the beam electrons. It is shown that the space charge limiting (critical) current decreases with growth of the External Magnetic Field, and that there is an optimal induction value of the Magnetic Field at which the critical current for the onset of virtual cathode oscillations in the electron beam is minimum. For the strong External Magnetic Field the space charge limiting current corresponds to the analytical relation derived under the assumption that the motion of the electron beam is one-dimensional [D.J. Sullivan, J.E. Walsh, E. Coutsias, in: V.L. Granatstein, I. Alexeff (Eds.), Virtual Cathode Oscillator (Vircator) Theory, in: High Power Microwave Sources, vol. 13, Artech House Microwave Library, 1987, Chapter 13]. Such behavior is explained by the characteristic features of the dynamics of electron space charge in the longitudinal and radial directions in the drift space at the different External Magnetic Fields.
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effect of External Magnetic Field on critical current for the onset of virtual cathode oscillations in relativistic electron beams
Physics Letters A, 2008Co-Authors: A E Hramov, Alexey A Koronovskii, Mikhail Morozov, Alexander MushtakovAbstract:In this Letter we research the space charge limiting current value at which the oscillating virtual cathode is formed in the relativistic electron beam as a function of the External Magnetic Field guiding the beam electrons. It is shown that the space charge limiting (critical) current decreases with growth of the External Magnetic Field, and that there is an optimal induction value of the Magnetic Field at which the critical current for the onset of virtual cathode oscillations in the electron beam is minimum. For the strong External Magnetic Field the space charge limiting current corresponds to the analytical relation derived under the assumption that the motion of the electron beam is one-dimensional [D.J. Sullivan, J.E. Walsh, E. Coutsias, in: V.L. Granatstein, I. Alexeff (Eds.), Virtual Cathode Oscillator (Vircator) Theory, in: High Power Microwave Sources, vol. 13, Artech House Microwave Library, 1987, Chapter 13]. Such behavior is explained by the characteristic features of the dynamics of electron space charge in the longitudinal and radial directions in the drift space at the different External Magnetic Fields.
A E Hramov - One of the best experts on this subject based on the ideXlab platform.
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high power microwave amplifier based on overcritical relativistic electron beam without External Magnetic Field
Applied Physics Letters, 2015Co-Authors: S A Kurkin, Alexey A Koronovskii, Nikita S Frolov, A O Rak, A A Kuraev, A E HramovAbstract:The high-power scheme for the amplification of powerful microwave signals based on the overcritical electron beam with a virtual cathode (virtual cathode amplifier) has been proposed and investigated numerically. General output characteristics of the virtual cathode amplifier including the dependencies of the power gain on the input signal frequency and amplitude have been obtained and analyzed. The possibility of the geometrical working frequency tuning over the range about 8%–10% has been shown. The obtained results demonstrate that the proposed virtual cathode amplifier scheme may be considered as the perspective high-power microwave amplifier with gain up to 18 dB, and with the following important advantages: the absence of External Magnetic Field, the simplicity of construction, the possibility of geometrical frequency tuning, and the amplification of relatively powerful microwave signals.
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microwave radiation power of relativistic electron beam with virtual cathode in the External Magnetic Field
Applied Physics Letters, 2013Co-Authors: S A Kurkin, A E Hramov, Alexey A KoronovskiiAbstract:The study of the output power of the electroMagnetic radiation of the relativistic electron beam (REB) with virtual cathode in the presence of External Magnetic Field has been found out. The typical dependencies of the output microwave power of the vircator versus External Magnetic Field have been analyzed by means of 3D electroMagnetic simulation. It has been shown that the power of vircator demonstrates several maxima with External Magnetic Field growth. The characteristic features of the power behavior are determined by the conditions of the virtual cathode formation in the presence of the External transversal Magnetic Field and the REB self-Magnetic Fields.
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effect of External Magnetic Field on critical current for the onset of virtual cathode oscillations in relativistic electron beams
Physics Letters A, 2008Co-Authors: A E Hramov, Alexey A Koronovskii, Mikhail Morozov, Alexander MushtakovAbstract:In this Letter we research the space charge limiting current value at which the oscillating virtual cathode is formed in the relativistic electron beam as a function of the External Magnetic Field guiding the beam electrons. It is shown that the space charge limiting (critical) current decreases with growth of the External Magnetic Field, and that there is an optimal induction value of the Magnetic Field at which the critical current for the onset of virtual cathode oscillations in the electron beam is minimum. For the strong External Magnetic Field the space charge limiting current corresponds to the analytical relation derived under the assumption that the motion of the electron beam is one-dimensional [D.J. Sullivan, J.E. Walsh, E. Coutsias, in: V.L. Granatstein, I. Alexeff (Eds.), Virtual Cathode Oscillator (Vircator) Theory, in: High Power Microwave Sources, vol. 13, Artech House Microwave Library, 1987, Chapter 13]. Such behavior is explained by the characteristic features of the dynamics of electron space charge in the longitudinal and radial directions in the drift space at the different External Magnetic Fields.
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effect of External Magnetic Field on critical current for the onset of virtual cathode oscillations in relativistic electron beams
Physics Letters A, 2008Co-Authors: A E Hramov, Alexey A Koronovskii, Mikhail Morozov, Alexander MushtakovAbstract:In this Letter we research the space charge limiting current value at which the oscillating virtual cathode is formed in the relativistic electron beam as a function of the External Magnetic Field guiding the beam electrons. It is shown that the space charge limiting (critical) current decreases with growth of the External Magnetic Field, and that there is an optimal induction value of the Magnetic Field at which the critical current for the onset of virtual cathode oscillations in the electron beam is minimum. For the strong External Magnetic Field the space charge limiting current corresponds to the analytical relation derived under the assumption that the motion of the electron beam is one-dimensional [D.J. Sullivan, J.E. Walsh, E. Coutsias, in: V.L. Granatstein, I. Alexeff (Eds.), Virtual Cathode Oscillator (Vircator) Theory, in: High Power Microwave Sources, vol. 13, Artech House Microwave Library, 1987, Chapter 13]. Such behavior is explained by the characteristic features of the dynamics of electron space charge in the longitudinal and radial directions in the drift space at the different External Magnetic Fields.
Jiayong Zhong - One of the best experts on this subject based on the ideXlab platform.
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suppressing kelvin helmholtz instability with an External Magnetic Field
Plasma Physics and Controlled Fusion, 2020Co-Authors: Wei Sun, Jiayong Zhong, Zhu Lei, Shu Zhang, Lifeng Wang, Kaige Zhao, Yongli Ping, Bo Han, Dawei YuanAbstract:We discuss the formation of a Kelvin-Helmholtz instability (KHI) produced by a laser-driven thin separate plastic (CH) foil plasma. The experimental design consists of magnetized plasma driven by intense laser irradiation and a small cylindrical permanent magnet. By comparing situations with and without an External Magnetic Field, we found that the KHI showed different rolling features which could be effectively suppressed by an External Magnetic Field. A quantitative analysis shows the consistency between the experiments and theory.
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the effect of External Magnetic Field on the linear stage evolution of kelvin helmholtz instability in laser driven plasma
High Energy Density Physics, 2019Co-Authors: Wei Sun, Jiayong Zhong, Shu Zhang, Bo Han, Bowei Tong, L F Wang, K G Zhao, J Y Liu, B J ZhuAbstract:Abstract A Kelvin–Helmholtz instability (KHI) is a fundamental physical process of fluids and magnetized plasma. We report the experimental formation of a KHI produced by intense laser-driven thin plastic foils. For an External Magnetic Field in different directions, the KHI shows different evolutionary features. A theoretical derivation shows that an External Magnetic Field has a stronger effect on KHI growth when its component is perpendicular to the plasma flow. A linear evolutionary stage of the KHI is captured by optimizing the target design, which is reproduced by FLASH simulation.
Davoud Dorranian - One of the best experts on this subject based on the ideXlab platform.
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effect of obliqueness and External Magnetic Field on the characteristics of dust acoustic solitary waves in dusty plasma with two temperature nonthermal ions
journal of theoretical and applied physics, 2015Co-Authors: Akbar Sabetkar, Davoud DorranianAbstract:In this paper, a theoretical investigation has been made of obliquely propagating dust acoustic solitary wave (DASW) structures in a cold magnetized dusty plasma consisting of a negatively charged dust fluid, electrons, and two different types of nonthermal ions. The Zakharov–Kuznetsov (ZK) and modified Zakharov–Kuznetsov (MZK) equations, describing the small but finite amplitude DASWs, are derived using a reductive perturbation method. The combined effects of the External Magnetic Field, obliqueness (i.e. the propagation angle), and the presence of second component of nonthermal ions, which are found to significantly modify the basic features (viz. amplitude, width, polarity) of DASWs, are explicitly examined. The results show that the External Magnetic Field, the propagation angle, and the second component of nonthermal ions have strong effects on the properties of dust acoustic solitary structures. The solitary waves may become associated with either positive potential or negative potential in this model. As the angle between the direction of External Magnetic Field and the propagation direction of solitary wave increases, the amplitude of the solitary wave (for both positive potential and negative potential) increases. With changing this angle, the width of solitary wave shows a maximum. The magnitude of the External Magnetic Field has no direct effect on the solitary wave amplitude. However, with decreasing the strength of Magnetic Field, the width of DASW increases.
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effect of obliqueness of External Magnetic Field on the characteristics of magnetized plasma wakeField
journal of theoretical and applied physics, 2013Co-Authors: Maryam Manouchehrizadeh, Davoud DorranianAbstract:A direct three-dimensional model to study the wakeField in underdense magnetized plasma is introduced. The model is based on an analytic procedure by Laplace transformation for calculating the magnetized plasma wake equations. WakeField is excited using a high-intensity ultrashort laser beam. In the presence of External Magnetic Field perpendicular to the direction of the laser pulse propagation direction, plasma electrons rotate around the Magnetic Field lines, leading to the generation of an electroMagnetic component of the plasma wakes at plasma frequency. This component is polarized perpendicularly to the direct current Magnetic Field lines and propagates in the forward direction and normal direction with respect to the laser pulse propagation direction, both perpendiculars to the direction of the applied Magnetic Field. Intensity of the radiation in different plasma densities and different Magnetic Field strengths has been observed.
Dawei Yuan - One of the best experts on this subject based on the ideXlab platform.
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suppressing kelvin helmholtz instability with an External Magnetic Field
Plasma Physics and Controlled Fusion, 2020Co-Authors: Wei Sun, Jiayong Zhong, Zhu Lei, Shu Zhang, Lifeng Wang, Kaige Zhao, Yongli Ping, Bo Han, Dawei YuanAbstract:We discuss the formation of a Kelvin-Helmholtz instability (KHI) produced by a laser-driven thin separate plastic (CH) foil plasma. The experimental design consists of magnetized plasma driven by intense laser irradiation and a small cylindrical permanent magnet. By comparing situations with and without an External Magnetic Field, we found that the KHI showed different rolling features which could be effectively suppressed by an External Magnetic Field. A quantitative analysis shows the consistency between the experiments and theory.
