Phase Decoherence Within Intense Chorus Wave Packets Constrains the Efficiency of Nonlinear Resonant Electron Acceleration
Phase Decoherence Within Intense Chorus Wave Packets Constrains the Efficiency of Nonlinear Resonant Electron Acceleration
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DOI：
10.1029/2020gl089807
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发表时间：
2020-10
影响因子：
5.2
通讯作者：
X.‐J. Zhang;O. Agapitov;A. Artemyev;D. Mourenas;V. Angelopoulos;W. Kurth;J. Bonnell;G. Hospodarsky
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文献类型：
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作者：
X.‐J. Zhang;O. Agapitov;A. Artemyev;D. Mourenas;V. Angelopoulos;W. Kurth;J. Bonnell;G. Hospodarsky
电子共振与哨声模式波的相互作用传统上被认为是辐射带动力学的主要驱动因素之一。描述它的两个主要理论概念是低振幅波的电子散射的准线性理论和强波的电子共振俘获和相位聚束的非线性理论。这两个概念都成功地描述了波粒相互作用的某些方面，但预测了相对论性电子加速的明显不同的时间尺度。在这项研究中，我们研究了可以降低非线性相互作用效率的效应，并弥合了这两种模型预测之间的差距。我们研究了在哨声模式波包内观察到的随机波相位和频率变化对非线性相互作用的影响。我们的研究结果表明，相位相干性和频率波动应该被考虑在内，以准确地模拟电子非线性共振加速度，并且，随着波幅调制，它们可以将加速度率降低到现实的，适度的水平。
Electron resonant interaction with whistler mode waves is traditionally considered as one of the main drivers of radiation belt dynamics. The two main theoretical concepts available for its description are quasi‐linear theory of electron scattering by low‐amplitude waves and nonlinear theory of electron resonant trapping and phase bunching by intense waves. Both concepts successfully describe some aspects of wave‐particle interactions but predict significantly different timescales of relativistic electron acceleration. In this study, we investigate effects that can reduce the efficiency of nonlinear interactions and bridge the gap between the predictions of these two types of models. We examine the effects of random wave phase and frequency variations observed inside whistler mode wave packets on nonlinear interactions. Our results show that phase coherence and frequency fluctuations should be taken into account to accurately model electron nonlinear resonant acceleration and that, along with wave amplitude modulation, they may reduce acceleration rates to realistic, moderate levels.