Electrostatic electron cyclotron instabilities near the upper hybrid layer due to electron ring distributions
Electrostatic electron cyclotron instabilities near the upper hybrid layer due to electron ring distributions
复制标题
由于电子环分布，上混合层附近的静电电子回旋不稳定性
DOI：
10.1088/0741-3335/58/9/095002
复制
发表时间：
2016
影响因子：
2.2
通讯作者：
L. Daldorff
中科院分区：
文献类型：
--
作者：
B. Eliasson;D. Speirs;L. Daldorff
本文对磁化等离子体中含有伯恩斯坦模的静电电子回旋不稳定性进行了理论研究。麦克斯韦等离子体中存在的稀薄热环分布降低了电子伯恩斯坦模的上混合分支的频率，直到它与最近的下分支合并，从而产生不稳定性。不稳定性发生时，上混合频率是略高于第三，第四，和更高的电子回旋谐波，并产生一个狭窄的频谱波周围的电子回旋谐波最接近的上混合频率。对于一个稀薄的冷环分布与麦克斯韦分布一起，不稳定性也可以发生在第二电子回旋谐波附近。无噪声Vlasov模拟被用来评估理论的线性增长率和频谱，并研究不稳定性的非线性演化。实验室和电离层加热实验的结果的相关性进行了讨论。
A theoretical study is presented of the electrostatic electron cyclotron instability involving Bernstein modes in a magnetized plasma. The presence of a tenuous thermal ring distribution in a Maxwellian plasma decreases the frequency of the upper hybrid branch of the electron Bernstein mode until it merges with the nearest lower branch with a resulting instability. The instability occurs when the upper hybrid frequency is somewhat above the third, fourth, and higher electron cyclotron harmonics, and gives rise to a narrow spectrum of waves around the electron cyclotron harmonic nearest to the upper hybrid frequency. For a tenuous cold ring distribution together with a Maxwellian distribution an instability can take place also near the second electron cyclotron harmonic. Noise-free Vlasov simulations are used to assess the theoretical linear growth-rates and frequency spectra, and to study the nonlinear evolution of the instability. The relevance of the results to laboratory and ionospheric heating experiments is discussed.