Macroscopic quasi‐linear theory and particle‐in‐cell simulation of helium ion anisotropy instabilities
Macroscopic quasi‐linear theory and particle‐in‐cell simulation of helium ion anisotropy instabilities
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DOI：
10.1002/2015ja021495
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发表时间：
2015-08
期刊：
影响因子：
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通讯作者：
P. Yoon;J. Seough;J. Hwang;Y. Nariyuki
中科院分区：
文献类型：
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作者：
P. Yoon;J. Seough;J. Hwang;Y. Nariyuki
观测到太阳风中的质子和氦离子具有各向异性的温度分布。各向异性似乎受到各种边缘不稳定条件的限制。研究大尺度太阳风模式中各种温度各向异性的全球动力学和分布的有效方法之一可能是基于宏观准线性方法。本文基于准线性理论与格子模拟比较，研究了质子和氦离子的各向异性不稳定性。结果表明，宏观拟线性格式较准确地再现了粒子温度的整体动态发展过程。然而，波动能量在时间上的发展却显示出一些不那么严格的比较，这表明虽然准线性方法对于粒子动力学是可以接受的，但波浪分析可能需要更高阶的物理，如波-波耦合或非线性波粒相互作用。
The protons and helium ions in the solar wind are observed to possess anisotropic temperature profiles. The anisotropy appears to be limited by various marginal instability conditions. One of the efficient methods to investigate the global dynamics and distribution of various temperature anisotropies in the large‐scale solar wind models may be that based upon the macroscopic quasi‐linear approach. The present paper investigates the proton and helium ion anisotropy instabilities on the basis of the quasi‐linear theory versus particle‐in‐cell simulation. It is found that the overall dynamical development of the particle temperatures is quite accurately reproduced by the macroscopic quasi‐linear scheme. The wave energy development in time, however, shows somewhat less restrictive comparisons, indicating that while the quasi‐linear method is acceptable for the particle dynamics, the wave analysis probably requires higher‐order physics, such as wave‐wave coupling or nonlinear wave‐particle interaction.