A simulation study of electron hole distributions
A simulation study of electron hole distributions
复制标题
电子空穴分布的模拟研究
DOI：
10.1029/gl016i010p01137
复制
发表时间：
1989
影响因子：
5.2
通讯作者：
F. Coroniti
中科院分区：
文献类型：
--
作者：
M. Ashour‐Abdalla;R. Richard;F. Coroniti
窄带静电噪声(NEN)在地球·S遥远的磁尾上经常被观测到。NEN在100HZ和316HZ之间呈现光谱峰值，并且非常脉冲，具有在10−4−10−3V/m√HZ范围内的峰值幅度。N_(En)代表了低能电子速度分布中空穴产生的等离子体波模式。本文用数值模拟的方法证明了在中等尺寸的电子空穴存在的情况下，激发了一个波模。在模拟中，模式以低幅度饱和，与观测结果一致，而不破坏空穴。结果表明，NEN的爆发式行为是由于这些非标准模的持续存在以及它们能够被各种弱自由能量源激发所致。
Narrowband electrostatic noise (NEN) is frequently observed in the Earth‧s distant magnetotail. NEN exhibits a spectral peak between 100 and 316 Hz and is very impulsive, having a peak amplitude in the range 10−4−10−3V/m√Hz. It has been suggested that NEN represents a plasma wave mode which results from a hole in the low energy electron velocity distribution. In this paper, it is shown by means of numerical simulation that a wave mode is excited in the presence of a modest sized electron hole. In the simulations the mode saturates at low amplitudes, in agreement with observations, without destroying the hole. It is suggested that the burst-like behavior of NEN is due to the persistence of these nonstandard modes and their ability to be excited by a variety of weak free energy sources.