Two-dimensional hybrid simulations of the oblique electromagnetic alpha/proton instability in the solar wind
Two-dimensional hybrid simulations of the oblique electromagnetic alpha/proton instability in the solar wind
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DOI：
10.1063/1.3116651
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发表时间：
2009-04
影响因子：
2.2
通讯作者：
Q. Lu;A. Du;Xing Li
中科院分区：
文献类型：
--
作者：
Q. Lu;A. Du;Xing Li
在太阳风中，观测到α粒子的流动速度比核心质子快。本文采用二维混合模拟方法研究了低β等离子体中α/质子束不稳定性激发的斜Alfven波的非线性演化。激发波的传播角在一个有限的范围内，表明斜阿尔芬波的产生。在非线性演化过程中，波的波数和频率都向较小的值漂移，传播角减小。同时，主模的传播角也发生变化。根据线性理论，最终等离子体系统达到边缘稳定状态。
In the solar wind, alpha particles are observed to flow faster than the core protons. In this paper, two-dimensional hybrid simulations are performed to investigate the nonlinear evolution of oblique Alfven waves excited by an alpha/proton beam instability in a low beta plasma. The propagation angles of the excited waves are within a finite range suggesting the generation of oblique Alfven waves. During the nonlinear evolution, both the wave numbers and frequencies of the waves drift to smaller values, and the propagation angles decrease. At the same time, the propagation angle of the dominant mode also changes. Eventually the plasma system reaches a marginally stable state according to linear theory.