Using the full relativistic test particle (TP) simulation code, we investigate the parametric dependence of electron scattering and phase space density evolution driven by magnetosonic (MS) waves at L = 4.5 both inside and outside the plasmapause. The scattering effects caused by Landau resonance, bounce resonance, and the transit‐time effect are all involved in the study. The net scattering effects are evaluated in the form of diffusion coefficients with different combinations of MS wave parameters, such as frequency bandwidth and wave normal angle, and ambient plasma density. The results demonstrate that (1) Landau resonance and the transit‐time effect dominate the electron scattering inside and outside the plasmapause, respectively, while both are modulated by bounce resonant scattering; (2) bounce resonant scattering becomes more important with narrowband MS waves; (3) electron scattering induced by MS waves is highly sensitive to wave normal angle. The temporal phase space density (PSD) evolution obtained from 2‐D kinetic Fokker‐Planck simulations shows that MS waves with larger wave normal angles are more likely to generate electron butterfly pitch angle distributions (PADs) for hundreds of keV electrons outside the plasmapause. Our study suggests that the electron butterfly distribution has important implications for revealing the combined scattering of MS wave‐particle interactions, and the combination of the multiple scattering mechanisms should be carefully incorporated in future global modeling of radiation belt dynamics.

中文翻译：

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磁声波驱动电子蝶形螺距角分布形成的参数相关性

使用完整的相对论测试粒子（TP）模拟代码，我们研究了L处磁声（MS）波驱动的电子散射和相空间密度演化的参数依赖性 =血浆暂停的内部和外部均为4.5。朗道共振，弹跳共振和传播时间效应引起的散射效应都参与了这项研究。净散射效应以扩散系数的形式进行评估，该扩散系数具有MS波参数（例如频率带宽和波法向角）以及环境等离子体密度的不同组合。结果表明：（1）Landau共振和渡越时间效应分别控制了等离子体暂停内部和外部的电子散射，而两者均受到反弹共振散射的调制；（2）窄带MS波的反弹共振散射变得尤为重要；（3）MS波引起的电子散射对波法向角高度敏感。从二维动力学Fokker-Planck模拟获得的时间相空间密度（PSD）演化表明，具有较大波法向角的MS波更有可能为等离子暂停以外的数百个keV电子产生电子蝶形俯仰角分布（PAD）。我们的研究表明，电子蝶形分布对于揭示MS波粒子相互作用的组合散射具有重要意义，并且在未来的辐射带动力学全局建模中应仔细考虑多种散射机制的组合。