论文标题
带有等离子喷气的当前表中的不稳定性
Instabilities in a current sheet with plasma jet
论文作者
论文摘要
我们研究具有等离子射流的磁流体动力电流板的稳定性问题。流动方向垂直于当前板的正常，我们分析了两种情况：（1）流动沿磁场的反平行分量； （2）流动垂直于磁场的反平行分量。具有不可压缩条件的通用方程集得出并作为边界值解决方案求解。对于第一种情况，我们表明，流链模式被磁场稳定在$ v_0/b_0 \ Lessim 2 $中，其中$ v_0 $和$ b_0 $是喷射速度和上游AlfVén速度，并且它不受电阻率的影响。流式香肠模式以$ v_0/b_0 \ Lessim 1 $稳定，并且可以以有限的电阻率传输到流撕裂模式。尽管最大生长速率和lundquist数字之间的缩放关系保持不变，但流撕裂模式的增长率比纯撕裂模式更大。当射流垂直于磁场的反平行成分时，最不稳定的香肠模式通常是垂直的（沿喷气的波矢量），而无需导向场。但是，对于有限的导向场，最不稳定的香肠模式可以倾斜，具体取决于喷射速度和指南强度。
We study the stability problem of a magnetohydrodynamic current sheet with the presence of a plasma jet. The flow direction is perpendicular to the normal of the current sheet and we analyze two cases: (1) The flow is along the anti-parallel component of the magnetic field; (2) The flow is perpendicular to the anti-parallel component of the magnetic field. A generalized equation set with the condition of incompressibility is derived and solved as a boundary-value-problem. For the first case, we show that, the streaming kink mode is stabilized by the magnetic field at $V_0/B_0 \lesssim 2$, where $V_0$ and $B_0$ are the jet speed and upstream Alfvén speed, and it is not affected by resistivity significantly. The streaming sausage mode is stabilized at $V_0/B_0 \lesssim 1$, and it can transit to the streaming tearing mode with a finite resistivity. The streaming tearing mode has larger growth rate than the pure tearing mode, though the scaling relation between the maximum growth rate and the Lundquist number remains unchanged. When the jet is perpendicular to the anti-parallel component of the magnetic field, the most unstable sausage mode is usually perpendicular (wave vector along the jet) without a guide field. But with a finite guide field, the most unstable sausage mode can be oblique, depending on the jet speed and guide field strength.
