Evolution of electron phase‐space holes in 3D
Evolution of electron phase‐space holes in 3D
复制标题
3D 电子相空间空穴的演化
DOI：
10.1029/2000gl012383
复制
发表时间：
2001
影响因子：
5.2
通讯作者：
Martin V. Goldman
中科院分区：
文献类型：
--
作者：
M. Oppenheim;G. Vetoulis;D. Newman;Martin V. Goldman
电子相空间空穴是在双流不稳定性的非线性阶段通常产生的耗尽电子密度区域。最近，双极电场结构-电子空穴的签名-已被确定在极光电离层的加速区域。本文使用大规模并行PIC模拟比较了电子空穴在2-D和3-D中的演化。在二维中，空穴在数百个等离子体周期后衰减，同时发射静电哨声波。在3-D模拟中，电子空穴也变得不稳定并产生哨声，但由于2-D中不存在的物理过程，能量从哨声中流出并进入高度垂直的低混合模式。由于这种差异，三维孔不会像二维孔那样衰减。2-D和3-D演化之间的差异可能对极光电离层中的空穴寿命和波的产生具有重要意义。
Electron phase‐space holes are regions of depleted electron density commonly generated during the nonlinear stage of the two‐stream instability. Recently, bipolar electric field structures—a signature of electron holes —have been identified in the acceleration region of the auroral ionosphere. This paper compares the evolution of electron holes in 2‐D and 3‐D using massively‐parallel PIC simulations. In 2‐D, the holes decay after hundreds of plasma periods while emitting electrostatic whistler waves. In the 3‐D simulations, electron holes also go unstable and generate whistlers but, due to physical processes not present in 2‐D, energy flows out of the whistlers and into highly perpendicular lower hybrid modes. As a result of this difference, 3‐D holes do not decay as far as 2‐D holes. The differences between 2‐D and 3‐D evolution may have important implications for hole longevity and wave generation in the auroral ionosphere.