论文标题

从碰撞到强碰撞的射流与背景之间相互作用的实验室研究

Laboratory investigation of the interaction between the jet and background, from collisionless to strong collision

论文作者

Lei, Z., Zhao, Z. H., Xie, Y., Yuan, W. Q., Li, 1 L. X., Gu, H. C., Li, X. Y., Zhu, B. Q., Zhu, J. Q., Zhu, S. P., He, X. T., Qiao, B.

论文摘要

超音速射流与背景之间的相互作用会影响恒星形成的过程,这种相互作用还会导致射流通过冲击波的速度,方向和密度变化。但是,由于当前天文设施的局限性,精细的冲击结构和详细的相互作用过程仍然不清楚。在这里,我们通过激光驱动的实验研究了不同碰撞状态下的血浆动力学。在碰撞情况的光学诊断中显示了双震结构,但是综合的自我发射X射线特征是不同的。对于固体塑料半球障碍物,观察到两层减震发射,对于相对较低的激光驱动的等离子体核心,仅显示了一种冲击发射。在两种情况下,通过与高密度背景的交互作用,等离子体喷射均由$ 50 ^{\ circ} $偏转。对于无碰撞病例,观察到细丝结构,细丝的平均宽度大致与离子皮肤深度相同。在所有相互作用情况下都观察到高能电子。我们分别通过2D/3D流体动力模拟和细胞中的粒子模拟介绍了冲击形成和细丝不稳定性的详细过程。我们的结果还可以应用于Herbig-Haro(HH)110/270系统中的冲击结构,实验表明可以将影响点推入云的内部。

The interaction between the supersonic jet and background can influence the process of star formation, and this interaction also results in a change of the jet's velocity, direction and density through shock waves. However, due to the limitations of current astronomical facilities, the fine shock structure and the detailed interaction process still remain unclear. Here we investigate the plasma dynamics under different collision states through laser-driven experiments. A double-shock structure is shown in the optical diagnosis for collision case, but the integrated self-emitting X-ray characteristic is different. For solid plastic hemisphere obstacle, two-layer shock emission is observed, and for the relatively low-density laser-driven plasma core, only one shock emission is shown. And the plasma jets are deflected by $50 ^{\circ}$ through the interaction with the high-density background in both cases. For collisionless cases, filament structures are observed, and the mean width of filaments is roughly the same as the ion skin depth. High-energy electrons are observed in all interaction cases. We present the detailed process of the shock formation and filament instability through 2D/3D hydrodynamic simulations and particle-in-cell simulations respectively. Our results can also be applied to explain the shock structure in the Herbig-Haro (HH) 110/270 system, and the experiments indicate that the impact point may be pushed into the inside part of the cloud.

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