Simulation and Quasi‐linear Theory of Magnetospheric Bernstein Mode Instability
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS(2018)
摘要
Multiple-harmonic electron cyclotron emissions, often known in the literature as the (n + 1/2)f(ce) emissions, are a common occurrence in the magnetosphere. These emissions are often interpreted in terms of the Bernstein mode instability driven by the electron loss cone velocity distribution function. Alternatively, they can be interpreted as quasi-thermal emission of electrostatic fluctuations in magnetized plasmas. The present paper carries out a one-dimensional relativistic electromagnetic particle-in-cell simulation and also employs a reduced quasi-linear kinetic theoretical analysis in order to compare against the simulation. It is found that the Bernstein mode instability is indeed excited by the loss cone distribution of electrons, but the saturation level of the electrostatic mode is quite low, and that the effects of instability on the electrons is rather minimal. This supports the interpretation of multiple-harmonic emission in the context of the spontaneous emission and reabsorption in quasi-thermal magnetized plasma in the magnetosphere.
更多查看译文
关键词
Bernstein mode,quasi-linear,particle-in-cell,instability,loss cone,multiple-harmonic cyclotron
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络