Resonance Interaction of Relativistic Electrons with Ion-Cyclotron Waves. I. Specific Features of the Nonlinear Interaction Regimes
Resonance Interaction of Relativistic Electrons with Ion-Cyclotron Waves. I. Specific Features of the Nonlinear Interaction Regimes
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相对论电子与离子回旋波的共振相互作用。
DOI：
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
A. Demekhov
中科院分区：
文献类型：
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作者：
V. Grach;A. Demekhov
本文分析了地球辐射带中相对论电子与离子回旋波的共振相互作用。考虑了具有可变频率和不同振幅分布的超长波包。的非线性相互作用制度的具体特点进行了分析的基础上数值求解的粒子运动方程组沿着与这种相互作用的效率为一个单一的通过粒子通过波包。在这项工作的第一部分中，单个粒子的轨迹的特性进行了分析。波包的形状对众所周知的制度，如粒子捕获的波场和粒子的相位聚束，这导致在非均匀介质中的俯仰角的非零平均变化的影响，被认为是。它示出，在远离鞍的区域中的相平面上的分界线附近的颗粒的长时间停留导致在没有捕获的情况下的颗粒的俯仰角的强烈减小。这种非线性状态（定向散射）对于相对低的初始俯仰角是可能的。在这种情况下，螺距角减小的值取决于颗粒的初始相位。结果表明，对应于定向散射的轨迹可以被看作是一个过渡类型的轨迹之间的未捕获和捕获的粒子的轨迹。的螺距角的变化的定量估计，得到的，它被证实，粒子的定向散射和捕获的波场可以导致电子沉淀到损失锥。
We analyze the resonant interaction of relativistic electrons with ion-cyclotron waves in the Earth radiation belts. Finite-length wave packets with variable frequencies and different amplitude profiles are considered. Specific features of the nonlinear interaction regimes are analyzed on the basis of solving numerically a system of equations of the particle motion along with the efficiency of this interaction for a single pass of the particle through the wave packet. In the first part of this work, the peculiarities of the trajectories of individual particles are analyzed. The influence of the shape of the wave packet on the well-known regimes, such as particle trapping by the wave field and particle phase bunching, which leads to a non-zero average variation in the pitch angle in an inhomogeneous medium, are considered. It is shown that a long stay of a particle near the separatrix on the phase plane in the region far from the saddle leads to a strong decrease in the pitch angle of the particle in the absence of the trapping as well. This nonlinear regime (directed scattering) is possible for comparatively low initial pitch angles. In this case, the value of the pitch angle decrease depends on the initial phase of the particle. It is shown that the trajectories corresponding to the directed scattering can be regarded as a transitional type of trajectories, between the trajectories of the untrapped and trapped particles. Quantitative estimates of variations in the pitch angle are obtained, and it is confirmed that the directed scattering and trapping of particles by the wave field can lead to electron precipitation into the loss cone.