表征激光烧蚀等离子体中Biermann电池驱动的磁重联的时间演化
Characterizing the temporal evolution of Biermann-battery-driven magnetic reconnection in laser-ablated plasmas
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中文总结 AI 辅助
本研究通过改变激光焦点间距控制入流参数，利用激光汤姆逊散射系统表征Biermann电池驱动的磁重联时间演化，发现重联率主要由重联层局域物理过程控制，对全局入流条件不敏感。
中文摘要 AI 辅助
本文对两个激光产生的膨胀等离子体之间的磁重联进行了实验研究，重点评估不同初始条件下的重联率和能量转换。通过改变驱动激光焦点间距（1毫米和2毫米），我们系统地控制了入流参数。利用双向激光汤姆逊散射（LTS）系统探测重联区域，该系统可同时测量平行于流出方向及电流片方向的局域等离子体参数。基于我们建立的结合宏观能量与质量守恒定律、直接从LTS光谱推导上游磁场的方法，我们表征了电流片和重联率的时间演化。较大的焦点间距使等离子体泡在形成重联电流片之前能膨胀更长时间，从而产生不同的上游条件。然而，两种配置得到的上游磁场和重联率相当。这些结果表明，重联率对全局入流条件相对不敏感，一旦电流片形成，主要由重联层的局域物理过程控制。
英文摘要
This paper presents an experimental investigation of magnetic reconnection between two laser-produced expanding plasmas, focusing on the quantitative evaluation of the reconnection rate and energy conversion under varying initial conditions. By changing the separation distance between the drive laser focal spots (1 mm and 2 mm), we systematically controlled the inflow parameters. The reconnection region was probed using a two-directional laser Thomson scattering (LTS) system, which simultaneously measured the local plasma parameters parallel to the outflows and along the current sheet. Based on our established method incorporating macroscopic energy and mass conservation laws to derive the upstream magnetic field directly from LTS spectra, we characterized the temporal evolution of the current sheet and the reconnection rate. The larger spot separation allows the plasma bubbles to expand for a substantially longer time before the formation of a reconnection current sheet, resulting in different upstream conditions. Nevertheless, both configurations yielded comparable upstream magnetic fields and reconnection rates. These results suggest that the reconnection rate is relatively insensitive to the global inflow conditions and is primarily controlled by the local physics of the reconnection layer once a current sheet is formed.
