The structure of bow shocks formed by the interaction of pulsed-power driven magnetised plasma flows with conducting obstacles
The structure of bow shocks formed by the interaction of pulsed-power driven magnetised plasma flows with conducting obstacles
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DOI：
10.1063/1.4993187
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发表时间：
2017-07
影响因子：
2.2
通讯作者：
G. Burdiak;S. Lebedev;S. Bland;T. Clayson;J. Hare;L. Suttle;F. Suzuki-Vidal;D. C. Garcia
中科院分区：
文献类型：
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作者：
G. Burdiak;S. Lebedev;S. Bland;T. Clayson;J. Hare;L. Suttle;F. Suzuki-Vidal;D. C. Garcia
本文对磁化、碰撞、超阿尔文等离子体流与导电圆柱形障碍物相互作用产生的弓形激波的发展和结构进行了实验研究。具有嵌入的冻结磁场的等离子体流(REM∼20)是通过电流驱动烧蚀细铝丝而产生的，反向爆炸丝阵列Z-Pinch。结果表明，嵌入场相对于障碍物的方向对弓形激波结构有显著影响。当磁场与障碍物对准时，形成具有全局结构的尖锐的弓形激波，该结构简单地由快速磁声马赫数决定。当磁场与障碍物垂直时，就会发生磁悬垂。这导致了磁性前体的增长和随后磁化弓形激波的发展，该磁化弓形激波是由双流体效应所介导的，具有比平行几何中大许多倍的张开角和远离距离。通过改变..。
We present an experimental study of the development and structure of bow shocks produced by the interaction of a magnetised, collisional, super-Alfvenic plasma flow with conducting cylindrical obstacles. The plasma flow with an embedded, frozen-in magnetic field (ReM ∼ 20) is produced by the current-driven ablation of fine aluminium wires in an inverse, exploding wire array z-pinch. We show that the orientation of the embedded field with respect to the obstacles has a dramatic effect on the bow shock structure. When the field is aligned with the obstacle, a sharp bow shock is formed with a global structure that is determined simply by the fast magneto-sonic Mach number. When the field is orthogonal to the obstacle, magnetic draping occurs. This leads to the growth of a magnetic precursor and the subsequent development of a magnetised bow shock that is mediated by two-fluid effects, with an opening angle and a stand-off distance, that are both many times larger than in the parallel geometry. By changing th...