Electrostatic Turbulence and Debye-scale Structures in Collisionless Shocks
Electrostatic Turbulence and Debye-scale Structures in Collisionless Shocks
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无碰撞冲击中的静电湍流和德拜尺度结构
DOI：
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发表时间：
2019
影响因子：
4.9
通讯作者：
R. Strangeway
中科院分区：
文献类型：
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作者：
R. Wang;I. Vasko;F. Mozer;S. Bale;A. Artemyev;J. Bonnell;R. Ergun;B. Giles;P. Lindqvist;C. Russell;R. Strangeway
我们提出了100多个大振幅双极静电结构的分析，在准垂直超临界地球的弓形激波穿越，测量的磁层多尺度航天器。双极结构的发生被证明是紧密相关的磁场梯度在冲击过渡区。双极结构具有负静电势和几个德拜长度的空间尺度。双极结构传播的速度（在等离子体静止帧）的顺序的离子声速的冲击法线高度倾斜。我们认为双极结构是由入射离子和反射离子之间的双流不稳定性产生的离子相空间空穴。这是第一次确认的离子双流不稳定性在无碰撞冲击。
We present analysis of more than 100 large-amplitude bipolar electrostatic structures in a quasi-perpendicular supercritical Earth’s bow shock crossing, measured by the Magnetospheric Multiscale spacecraft. The occurrence of the bipolar structures is shown to be tightly correlated with magnetic field gradients in the shock transition region. The bipolar structures have negative electrostatic potentials and spatial scales of a few Debye lengths. The bipolar structures propagate highly oblique to the shock normal with velocities (in the plasma rest frame) of the order of the ion-acoustic velocity. We argue that the bipolar structures are ion phase space holes produced by the two-stream instability between incoming and reflected ions. This is the first identification of the ion two-stream instability in collisionless shocks.