Proton cyclotron and mirror instabilities in marginally stable solar wind plasma
Proton cyclotron and mirror instabilities in marginally stable solar wind plasma
复制标题
边缘稳定的太阳风等离子体中的质子回旋加速器和镜子不稳定性
DOI：
10.1093/mnras/stab3286
复制
发表时间：
2021
影响因子：
4.8
通讯作者：
Seough, J.
中科院分区：
文献类型：
--
作者：
Yoon, P. H.;Sarfraz, M.;Ali, Z.;Salem, C. S.;Seough, J.
本文提出了一种基于速度矩的准线性理论，该理论结合了弱不稳定质子回旋加速器（或等效的电磁离子回旋加速器）和质子镜不稳定性对太阳风等离子体的影响，该等离子体最初以过度的垂直质子温度各向异性为特征。本形式主义是现有模型的替代方案，因为弱不稳定模式的特征是分析形式主义，涉及弱增长率和/或流体理论色散关系的假设，代替基于超越等离子体色散函数的数值求根方法。这产生了用于分析所述不稳定性的准线性发展的有效数值平台。这种形式主义可能在全球太阳风建模工作的更大背景下有用，其中需要有效计算自洽波粒相互作用过程。与航天器观测的太阳风质子数据分布的直接比较表明，现有的拟线性计算的弱增长率形式产生了与观测一致的结果。
This paper formulates a velocity moment-based quasi-linear theory that combines the impacts of weakly unstable proton–cyclotron- (or, equivalently, electromagnetic ion cyclotron) and proton-mirror instabilities on the solar wind plasma initially characterized by an excessive perpendicular proton temperature anisotropy. The present formalism is an alternative to the existing model in that the weakly unstable modes are characterized by analytical formalism that involves the assumption of weak growth rate and/or fluid-theoretical dispersion relation, in place of numerical root-finding method based on the transcendental plasma dispersion function. This results in an efficient numerical platform for analyzing the quasi-linear development of the said instabilities. Such a formalism may be useful in the larger context of global solar wind modelling effort where an efficient calculation of self-consistent wave–particle interaction process is called for. A direct comparison with spacecraft observations of solar wind proton data distribution shows that the present weak growth rate formalism of quasi-linear calculation produces results that are consistent with the observation.