Evolution of the electron cyclotron drift instability in two-dimensions
Evolution of the electron cyclotron drift instability in two-dimensions
复制标题
电子回旋加速器二维漂移不稳定性的演化
DOI：
10.1063/1.5033896
复制
发表时间：
2018
影响因子：
2.2
通讯作者：
Y. Raitses
中科院分区：
文献类型：
--
作者：
S. Janhunen;A. Smolyakov;D. Sydorenko;M. Jimenez;I. Kaganovich;Y. Raitses
用高分辨粒子模拟方法研究了部分磁化等离子体中由电子E×B漂移驱动的电子回旋不稳定性(ECDI)。重点讨论了具有介质壁的有限长等离子体中沿磁场平行运动的二维效应。研究发现，这种不稳定性表现为一系列不断增长的回旋谐函数，表现为波破裂和复杂的非线性相互作用，特别是在短波长的离子密度涨落中表现得尤为明显。同时，离子和电子密度涨落的非线性演化以及反常电子流也表现出向长波方向的级联。在电子密度谱和反常电流涨落谱中最明显地观察到产生长波分量的倾向。一个沿磁场方向具有明显本征模结构的强而缓慢增长的模在较晚的非线性阶段发展，增强了长波凝聚的趋势。后一种沿磁场具有有限波长的模式被称为修正的双流不稳定性(MTSI)。结果表明，MTSI模式会导致电子的强烈平行加热。
The Electron Cyclotron Drift Instability (ECDI) driven by the electron $E\times B$ drift in partially magnetized plasmas is investigated with highly resolved particle-in-cell simulations. The emphasis is on two-dimensional effects involving the parallel dynamics along the magnetic field in a finite length plasma with dielectric walls. It is found that the instability develops as a sequence of growing cyclotron harmonics demonstrating wave breaking and complex nonlinear interactions, being particularly pronounced in ion density fluctuations at short wavelengths. At the same time, nonlinear evolution of fluctuations of the ion and electron density, as well as the anomalous electron current, shows cascade toward long wavelengths. Tendency to generate long wavelength components is most clearly observed in the spectra of the electron density and the anomalous current fluctuations. An intense but slowly growing mode with a distinct eigen-mode structure along the magnetic field develops at a later nonlinear stage enhancing the tendency toward long wavelength condensation. The latter mode having a finite wavelength along the magnetic field is identified as the Modified Two-Stream Instability (MTSI). It is shown that the MTSI mode results in strong parallel heating of electrons.