Theoretical model of the nonlinear resonant interaction of whistler-mode waves and field-aligned electrons
Theoretical model of the nonlinear resonant interaction of whistler-mode waves and field-aligned electrons
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DOI：
10.1063/5.0046635
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发表时间：
2021-05-01
影响因子：
2.2
通讯作者：
Ma, Q.
中科院分区：
文献类型：
--
作者：
Artemyev, A., V;Neishtadt, A., I;Ma, Q.
强哨声模式波和高能电子在地球辐射带中的非线性共振相互作用传统上由基于慢-快共振系统考虑的理论模型描述。这种模型将共振周围的电子动力学简化为单摆方程，该单摆方程提供了电子非线性散射（相位聚束）和相位捕获的解决方案。该方法的适用性限于不太小的电子节距角（即，足够大的电子磁矩），而模型预测矛盾的小俯仰角电子的测试粒子的结果。这项研究的重点是这样的场对齐（小间距角）的电子共振。我们证明了非线性共振相互作用可以用具有分界线交叉的快慢哈密顿系统来描述。对于第一回旋共振，这种相互作用的结果在电子俯仰角增加所有的共振电子，相反的俯仰角减少预测的钟摆方程散射电子。我们推导出了非线性共振相互作用向新机制转变的磁矩阈值。对于场取向的电子，该模型提供了非线性共振的磁矩变化的幅度。这个模型补充了现有的模型，不太小的俯仰角，并有助于强哨声模式波的非线性共振电子相互作用的理论。
The nonlinear resonant interaction of intense whistler-mode waves and energetic electrons in the Earth's radiation belts is traditionally described by theoretical models based on the consideration of slow-fast resonant systems. Such models reduce the electron dynamics around the resonance to the single pendulum equation that provides solutions for the electron nonlinear scattering (phase bunching) and phase trapping. Applicability of this approach is limited to not-too-small electron pitch-angles (i.e., sufficiently large electron magnetic moments), whereas model predictions contradict to the test particle results for small pitch-angle electrons. This study is focused on such field-aligned (small pitch-angle) electron resonances. We show that the nonlinear resonant interaction can be described by the slow-fast Hamiltonian system with the separatrix crossing. For the first cyclotron resonance, this interaction results in the electron pitch-angle increase for all resonant electrons, contrast to the pitch-angle decrease predicted by the pendulum equation for scattered electrons. We derive the threshold value of the magnetic moment of the transition to a new regime of the nonlinear resonant interaction. For field-aligned electrons, the proposed model provides the magnitude of magnetic moment changes in the nonlinear resonance. This model supplements existing models for not-too-small pitch-angles and contributes to the theory of the nonlinear resonant electron interaction with intense whistler-mode waves.