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1.
Wan Sui Ren 《International Journal of Infrared and Millimeter Waves》1985,6(6):433-447
This paper starts from the kinetic theory to expound the method of characteristics. Influence of the equilibrium distribution functionf
o upon analyzed result is fully investigated. Dispersion equation is rigorously derived in waveguide coordinate system in case of interaction between TE
mn
field in a circular waveguide and a single momentum ring-shaped electron beam. In the meantime, we make some critical review of previous papers and clarify their confusion and ambiguities. 相似文献
2.
K. E. Kreischer R. J. Temkin 《International Journal of Infrared and Millimeter Waves》1980,1(2):195-223
The linear theory of an electron cyclotron maser (ECM) operating at the fundamental is developed. A set of analytic expressions, valid for all TE cavity modes, is derived for the starting current and frequency detuning using the Vlasov-Maxwell equations in the weakly relativistic limit. These results are applicable for an arbitrary electron velocity distribution as well as any longitudinal distribution of the RF field. It is shown that the starting current can be expressed in a simple form which contains the Fourier trans-form of the longitudinal field distribution. Analytic results are presented for specific longitudinal field variations, including uniform, sinusoidal, and Gaussian. It is found that the starting characteristics of an ECM are strongly influenced by the axial dependence of the RF field, but weakly affected by the velocity spread of the electron beam. The problem of multimode oscillation is treated in the linear theory by using a Slater expansion of the cavity field. The complete formulation for mode competition based on this expansion is presented and preliminary results are derived. This comprehensive analysis of ECM linear theory should be useful as a diagnostic of ECM performance and should facilitate comparison between theory and experiment.Work supported by U.S.D.O.E. Contract DE-AC-02-80ER52059Supported by U.S. Department of EnergySupported by National Science Foundation 相似文献
3.
Liu Shenggang 《International Journal of Infrared and Millimeter Waves》1981,2(6):1253-1262
The problems concerning the specification of electron equilibrium distribution function for the kinetic theory of ECRM are investigated in this paper. After detailed analysis of the published equilibium distribution functions, several conclusion have been achieved. 相似文献
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A single nonlinear equation which describes the temporal evolution of the field amplitude of the electron cyclotron maser instability is derived self-consistently. The results deduced from this nonlinear equation are found to agree well with those of particle simulation. 相似文献
6.
为了打破二维模拟回旋脉塞的一些局限性,研究了电子回旋受激辐射的基本原理,使用唯象的描述方法,以统计物理学为基础,在电子回旋中心坐标系中完成了三维Yee网格模型中对电子注平衡态物理模型的数值建模,并结合PIC方法和FDTD算法进行电子回旋脉塞的数值模拟.为了减少计算时间,在模拟中加入了MPI并行算法,加速比能提高到2.7以上.最后以一个94 GHz的回旋振荡管为例,对它的整体结构进行了模拟,并通过对频谱,功率,工作模式等方面验证了模拟的正确性.
关键词:
电子回旋脉塞
Yee网格模型
PIC方法
FDTD算法 相似文献
7.
Zi-Chao Gao 《中国物理 B》2022,31(12):128401-128401
Based on the principle of electron cyclotron maser (ECM), gyrotrons are among the most promising devices to generate powerful coherent terahertz (THz) radiation and play a vital role in numerous advanced THz applications. Unfortunately, THz ECM systems using a conventional high-Q cavity were theoretically and experimentally demonstrated to suffer from strong ohmic losses, and, accordingly, the wave output efficiency was significantly reduced. A scheme to alleviate such a challenging problem is systematically investigated in this paper. The traveling-wave operation concept is employed in a 1-THz third harmonic gyrotron oscillator, which strengthens electron-wave interaction efficiency and reduces the ohmic dissipation, simultaneously. A lossy belt is added in the interaction circuit to stably constitute the traveling-wave interaction, and a down-tapered magnetic field is employed to further amplify the forward-wave (FW) component. The results demonstrate that the proportion of ohmic losses is nearly halved, and output efficiency is nearly doubled, which is promising for further advancement of high-power continuous-wave operation of the ECM-based devices. 相似文献
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The resoinance diffusion of electrons in velocity space caused by the excited EM wave fields is considered to be the dominant saturation process of cyclotron maser instability that is driven by an electron loss-cone distribution. An upper-bound of the saturation level is derived analytically. Since the resulting saturation level is low the resonance diffusion is indeed responsible for the saturation of the cyclotron maser instability. 相似文献
11.
Yuan-Zhao Yin 《International Journal of Infrared and Millimeter Waves》1993,14(8):1587-1600
The cyclotron autoresonace maser with a large-orbit electron ring in a dielectric-loaded waveguide has been analyzed. The stability properties are investigated self-consistently on the basis of the linearized Vlasov-Maxwell equations. The numerical results show the growth rate increases when the electron rotating ratio increases. And the dielectric liner can greatly reduce the energy of the electron beam. 相似文献
12.
L. Chen T. H. Kho A. T. Lin 《International Journal of Infrared and Millimeter Waves》1990,11(7):821-835
A general dispersion relation for the cyclotron autoresonance maser (CARM) that takes into account self-consistent couplings between TE, TM and ac space charge perturbations in a uniform planar waveguide is derived. The dispersion relation predicts enhanced growth rate due to ac space charge effects. Results from computer simulations of a planar CARM amplifier are presented to support this finding. 相似文献
13.
A. Orefice 《Il Nuovo Cimento D》1991,13(9):1141-1157
Summary The stages of the relativistic theory leading from the Maxwell-Vlasov system to the absorption and emission coefficients for
electromagnetic electron cyclotron waves in a thermonuclear magnetoactive plasma are critically followed, with a particular
attention to the approximations involved. Simple and general forms are obtained, holding to arbitrary order in the electron
Larmor radius expansion. The applicability limits of the lowest order in this expansion are analysed. 相似文献
14.
为了有效分析模式竞争,建立了回旋自谐振脉塞(CARM)多模束波互作用自洽非线性理论模型,并具体模拟研究了工作模式为TM51、频率为0.35 THz的高阶横磁模CARM中大轨道相对论电子束与多电磁模式的互作用过程。模拟结果表明:与回旋管不同,THz频段CARM可以有效工作于高阶TM模式,且具有较高的输出功率和增益;通过对工作参数的优化,可使工作模式的功率增长具有绝对优势,而竞争模式得到有效抑制;高阶TM模式THz频段CARM的性能对工作参数的变化十分敏感,在参数设计过程中必须对其进行多模束波互作用模拟分析。 相似文献
15.
为了有效分析模式竞争,建立了回旋自谐振脉塞(CARM)多模束波互作用自洽非线性理论模型,并具体模拟研究了工作模式为TM51、频率为0.35 THz的高阶横磁模CARM中大轨道相对论电子束与多电磁模式的互作用过程。模拟结果表明:与回旋管不同,THz频段CARM可以有效工作于高阶TM模式,且具有较高的输出功率和增益;通过对工作参数的优化,可使工作模式的功率增长具有绝对优势,而竞争模式得到有效抑制;高阶TM模式THz频段CARM的性能对工作参数的变化十分敏感,在参数设计过程中必须对其进行多模束波互作用模拟分析。 相似文献
16.
A. G. Demekhov D. L. Pasmanik V. Yu. Trakhtengerts 《Radiophysics and Quantum Electronics》1996,39(8):656-665
The dynamics of a cyclotron maser is considered in a two-level approximation with nonlinear inertia saturation of absorption due to background plasma heating. The conditions of the existence of a self-oscillation mode in the presence of a permanent source of energetic particles in this system and a particle acceleration process in adiabatic magnetic compression of the plasma are specified. The self-oscillation characteristics are studied numerically as functions of the parameters of the system.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 39, No. 8, pp. 988–1000, August, 1996.This work was supported in part by the Russian Foundation for Fundamental Research (Project Code No. 96-02-16473a). 相似文献
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Kinetic theory of electron-cyclotron resonance masers withasymmetry of the electron beam in a cavity
Dumbrajs O. Shenggang L. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1992,20(3):126-132
On the basis of kinetic theory, general relations for the starting current and frequency shift in electron-cyclotron resonance masers are derived in the case of eccentricity of the electron beam in a cavity. The influence of a misalignment of the beam and cavity on the gyrotron operation is discussed as an example 相似文献
19.
V. V. Parkhomchuk 《JETP Letters》2008,87(3):181-181
20.
Elnaz Khalilzadeh Amir Chakhmachi Behrouz Maraghechi 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2015,69(11):256
The influence of self-fields on the cyclotron maser instability in a hollow electron beam propagating parallel to a uniform axial magnetic field B 0 ê z in a dielectric loaded waveguide is investigated. The theoretical analysis is carried out within the framework of linearized Vlasov-Maxwell equations. It is assumed that the beam is thin with the radial thickness much smaller than the beam radius. A new dispersion relation for azimuthally symmetric electromagnetic perturbation is derived and analyzed numerically. The influence of self-fields on the cyclotron maser instability in a dielectric loaded waveguide for different dielectric medium is studied. It is found that unlike the hollow waveguide the growth rate is increased by increasing self-fields. The instability band width decreases due to the increasing self-fields. The maximum growth rate increases gradually as self-fields increase as regards a different dielectric medium. 相似文献