共查询到20条相似文献,搜索用时 0 毫秒
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Non-linear dynamical behaviour of electron acoustic waves (EAWs) is studied in a magnetized non-thermal plasma (containing inertial cold electrons, inertialess hot electrons following non-thermal distribution function, and static ions) via a fluid dynamical approach. A linear dispersion relation is derived and the propagation of two possible modes and their evolution are studied through the different plasma configuration parameters, such as non-thermality and external magnetic field strength. In a non-linear perturbation regime, a reductive perturbation technique is employed to derive the non-linear evolution equation and the analysis is executed for travelling plane waves in terms of a non-linear dynamical system to enlighten the numerous aspects of the phase space dynamics. The results of numerical simulation predict the existence of a wide class of non-linear structures, namely solitonic, periodic, quasiperiodic, and chaotic depending upon different controlling plasma parameters. Also, Poincaré return map analysis confirms these non-linear structures of the EAWs. 相似文献
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Jean-Louis Jauberteau Isabelle Jauberteau Osvaldo Daniel Cortzar Ana Megía-Macías 《等离子体物理论文集》2022,62(1):e202100066
In low-temperature magnetized plasma, Langmuir probe measurements must be corrected because of the electron diffusion through the sheath, which is formed around the probe collector. The correction factor, which is called the electron diffusion or electron sink parameter, depends on many other parameters such as the probe geometry, the electron diffusion coefficient, the sheath thickness, or the potential profile through the sheath. Based on a previous work, we determine the values of this parameter under different experimental conditions and we study the effect of the electron energy, of the probe-biased voltage, and of the magnetic field intensity on this parameter. The results are compared with theoretical models published in the literature. An empirical equation is determined to fit the diffusion parameter value versus magnetic field intensity. 相似文献
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Filamentation phenomenon is one of the most important outcomes of applying a strong magnetic field to low-pressure plasmas and dusty plasmas. In this article, the variation of filamentation phenomenon with neutral gas pressure and plasma density will be investigated using numerical simulations. It will be shown through these simulations how the formation of the filamentary patterns in the magnetized plasma results in a localized electric field structure that strongly contributes to the properties of the filamentary patterns. Based on the results of the simulations, a theoretical model is derived that relates the width of the filamentary patterns to the plasma density. The model has been successfully employed to predict the width of the patterns emerging in various simulations of the magnetized plasma. 相似文献
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磁化等离子体光子晶体是磁化等离子体和介质(真空)构成的人工周期性结构.本文用磁化等离子体的分段线形电流密度卷积(PLCDRC)时域有限差分(FDTD)算法分析了磁化等离子体光子晶体特性.分析了磁化等离子体参数对电磁带隙的影响.从时域的角度分析了高斯脉冲在磁化等离子体光子晶体中的传播过程,给出了时域反射和透射波形.从频域的角度给出了磁化等离子体光子晶体的电磁反射系数和透射系数,并对结果进行了分析.
关键词:
磁化等离子体
光子晶体
时域有限差分法 相似文献
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给出了一种新的计算各向异性磁化色散介质的有限差分(FDTD)算法,称为移位算子FDTD(SO-FDTD)算法,它利用算子之间的移位递推关系,将一类色散介质的包含介电常数的表达式写成有理分式函数形式,进而导出FDTD中一系列相关量之间的关系.通过计算各向异性等离子体平板对电磁波的反射系数和透射系数,验证了该算法的高效性和高精度,与JEC算法相比,可使计算效率提高数倍.
关键词:
磁化等离子体
电磁波
FDTD方法
各向异性 相似文献
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为进一步研究霍尔推进器壁面二次电子发射对推进器性能的影响,采用流体模型数值模拟了二次电子磁化效应的等离子体鞘层特性.得到二次电子磁化鞘层的玻姆判据.讨论了不同的磁场强度和方向、二次电子发射系数以及不同种类等离子体推进器的鞘层结构.结果表明:随器壁二次电子发射系数的增大,鞘层中粒子密度增加,器壁电势升高,鞘层厚度减小;鞘层电势及粒子密度随着磁场强度和方位角的增加而增加;而对于不同种类的等离子体,壁面电势和鞘层厚度也不同.这为霍尔推进器的磁安特性实验提供了理论解释.
关键词:
霍尔推进器
磁鞘
二次电子 相似文献
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Theoretical study of wave propagation along the coaxial waveguide filled with moving magnetized plasma 下载免费PDF全文
This paper presents detailed theoretical study on the theory of wave propagation along the coaxial waveguide filled with moving magnetized plasma (CWMMP). Making use of the Lorentz transformation and the constitutive transformation, Maxwell’s equations lead to the coupled non-homogeneous differential equations which govern the wave propagation in CWMMP, and then analytical solutions have been obtained. The discussion about the eigenvalues of the waves and detailed studies on the fields are carried out. It finds that the fields of the CWMMP are composed of two parts with different eigenvalues. Numerical calculations show that because of Doppler shift effect, the eigenvalues of the modes in such a case is quite different from those of the CWMMP. And a detailed discussion on the dispersion characteristic of CWMMP is presented. 相似文献
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基于高功率微波(HPM)混合气体传输模型,系统阐述了考虑磁效应条件下HPM窄波束在低电离层中传输时的聚焦与散焦原理,推导了考虑外加磁场和HPM热效应情况下,窄波束在低电离层中传输的非线性几何光学方程及聚焦和散焦特性描述参数,并对低电离层中的波束发散特性进行了仿真分析。仿真结果表明:低电离层表现出的散焦特性,使HPM窄波束发散,L,R,O,X波均发生了波束发散现象,且R波的波束发散角最大,O,X波次之,L波最小,但随着入射波频率的增加,这种差别逐渐减小;相同条件下,入射波频率越高,散焦现象越弱;一定入射波频率条件下,波束轴线上的场强越大,波束发散现象越明显。 相似文献
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The dispersive properties of a dielectric-rod loaded waveguide immersed in a magnetized annular plasma 总被引:4,自引:0,他引:4 下载免费PDF全文
Propagation properties of electromagnetic waves in a dielectric-rod waveguide immersed in a magnetized annular plasma are presented in this paper. The dispersion relations are derived and calculated. The results show that the dielectric-rod loading can make the structure less dispersive and the transmission frequency-band broadened. 相似文献
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基于高功率微波(HPM)混合气体传输模型,系统阐述了考虑磁效应条件下HPM窄波束在低电离层中传输时的聚焦与散焦原理,推导了考虑外加磁场和HPM热效应情况下,窄波束在低电离层中传输的非线性几何光学方程及聚焦和散焦特性描述参数,并对低电离层中的波束发散特性进行了仿真分析。仿真结果表明:低电离层表现出的散焦特性,使HPM窄波束发散,L,R,O,X波均发生了波束发散现象,且R波的波束发散角最大,O,X波次之,L波最小,但随着入射波频率的增加,这种差别逐渐减小;相同条件下,入射波频率越高,散焦现象越弱;一定入射波频率条件下,波束轴线上的场强越大,波束发散现象越明显。 相似文献
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采用磁化等离子体的分段线性电流密度卷积时域有限差分(PLCDRC-FDTD)算法研究具有单一缺陷层的一维磁化等离子体光子晶体的缺陷模特性. 从频域角度分析得到微分高斯脉冲的透射率,并讨论该光子晶体的缺陷层厚度、位置、周期常数和等离子体参数对其缺陷模的影响. 结果表明,改变位置和周期常数不会影响缺陷模的频率,改变缺陷层的厚度可以增加缺陷模数,改变等离子体参数能同时影响缺陷模的频率和峰值.
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磁化等离子体光子晶体
光子晶体
缺陷模
时域有限差分法 相似文献
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基于单粒子理论模型及积分算法,编写了单粒子轨道数值模拟程序———ALFA,分析了柱形和球形两种边界位形磁化等离子体靶中非热α粒子通过库仑碰撞对D-T等离子体加热的能量沉积率。在均匀背景磁场及相同的D-T等离子体密度、温度条件下,柱形边界中非热α粒子能量沉积率比球形边界更高。在相同等离子体温度及密度条件下,α粒子的能量沉积率随磁场的增大而增大,但计算结果表明,磁场的有效作用区域存在明显的上下限值,当等离子体内磁场小于下限阈值时,磁场增加对α粒子能量沉积率的提高贡献不大,而且当等离子体内磁场超过上限阈值后,磁场再增加对提高α粒子能量沉积率的作用也不明显。对不同几何尺寸的磁化等离子体靶,磁场有效作用区域的上下限值不同,靶尺寸越大,相应的上下限阈值越小。提高等离子体密度,可增加α粒子能量沉积率,也能降低磁场有效作用区域的上下限阈值。 相似文献
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基于单粒子理论模型及积分算法,编写了单粒子轨道数值模拟程序ALFA,分析了柱形和球形两种边界位形磁化等离子体靶中非热粒子通过库仑碰撞对D-T等离子体加热的能量沉积率。在均匀背景磁场及相同的D-T等离子体密度、温度条件下,柱形边界中非热粒子能量沉积率比球形边界更高。在相同等离子体温度及密度条件下,粒子的能量沉积率随磁场的增大而增大,但计算结果表明,磁场的有效作用区域存在明显的上下限值,当等离子体内磁场小于下限阈值时,磁场增加对粒子能量沉积率的提高贡献不大,而且当等离子体内磁场超过上限阈值后,磁场再增加对提高粒子能量沉积率的作用也不明显。对不同几何尺寸的磁化等离子体靶,磁场有效作用区域的上下限值不同,靶尺寸越大,相应的上下限阈值越小。提高等离子体密度,可增加粒子能量沉积率,也能降低磁场有效作用区域的上下限阈值。26035002 相似文献