Nonlinear Mirror and Weibel modes: peculiarities of quasi-linear dynamics
Nonlinear Mirror and Weibel modes: peculiarities of quasi-linear dynamics
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非线性镜像和 Weibel 模式：准线性动力学的特性
DOI：
10.5194/angeo-28-2161-2010
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发表时间：
2010
影响因子：
1.9
通讯作者：
G. Dudnikova
中科院分区：
文献类型：
--
作者：
O. Pokhotelov;R. Sagdeev;M. Balikhin;V. Fedun;G. Dudnikova
抽象的。发展了一个在不稳定阈值附近镜模非线性演化的理论。结果表明，在初始阶段，主要的不稳定性饱和提供了平坦的速度分布函数附近的小平行离子速度。在这种情况下，松弛的情况下，伴随着共振粒子相互作用的快速衰减，这是由一个较弱的绝热相互作用与镜像模式所取代。饱和等离子体状态可以被认为是静电BGK模式的磁性对应物。准线性饱和后，进一步的非线性情况下控制的模式耦合效应和非线性变化的离子拉莫尔半径。我们的分析模型进行了验证相关的数值模拟。测试粒子和PIC模拟确实表明，这是一个修改的分布函数在小的平行速度，导致在衰减的自由能驱动的镜像模式。讨论了与共振韦伯不稳定性的相似性。
Abstract. A theory for nonlinear evolution of the mirror modes near the instability threshold is developed. It is shown that during initial stage the major instability saturation is provided by the flattening of the velocity distribution function in the vicinity of small parallel ion velocities. The relaxation scenario in this case is accompanied by rapid attenuation of resonant particle interaction which is replaced by a weaker adiabatic interaction with mirror modes. The saturated plasma state can be considered as a magnetic counterpart to electrostatic BGK modes. After quasi-linear saturation a further nonlinear scenario is controlled by the mode coupling effects and nonlinear variation of the ion Larmor radius. Our analytical model is verified by relevant numerical simulations. Test particle and PIC simulations indeed show that it is a modification of distribution function at small parallel velocities that results in fading away of free energy driving the mirror mode. The similarity with resonant Weibel instability is discussed.
空间等离子体中的镜像不稳定性：孤子和椭圆曲线波
影响因子：
2.2
作者：
Istomin Y
通讯作者：
Istomin Y