Field reconstruction from proton radiography of intense laser driven magnetic reconnection
Field reconstruction from proton radiography of intense laser driven magnetic reconnection
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DOI：
10.1063/1.5092733
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发表时间：
2019-08-01
影响因子：
2.2
通讯作者：
Willingale, L.
中科院分区：
文献类型：
--
作者：
Palmer, C. A. J.;Campbell, P. T.;Willingale, L.
磁重联是一个对各种等离子体和磁场范围内的等离子体动力学和能量转移做出重大贡献的过程，包括惯性约束聚变实验、恒星日冕以及中子星等致密、高度磁化的物体。不同状态下的实验室实验可以帮助完善、扩展和测试描述重连接的理论模型的适用性。先前已经进行了探索中等强度（I-L 类似于 10(14) W cm(-2)）磁重联的激光等离子体实验，其中比尔曼电池效应自生成磁场，并使用质子射线照相术研究场动力学。在高激光强度（IL lambda L2>1018Wcm-2 mu m2）下，相对论表面电流和时变电鞘场产生方位磁场。这些强度的数值模型显示了磁场区域内可以达到磁能可以超过静止质量能量的阈值的条件，使得 sigma(cold)=B-2/(mu(0)n(e)m(e)c(2)) > 1 [A. E.雷蒙德等人，物理学。修订版 E 98, 043207 (2018)]。这里介绍的是高强度（类似于 10(18) W cm(-2)）激光驱动磁重联几何结构的质子射线照相分析。使用场重建算法恢复路径积分磁场，以量化场强、几何形状和演化。
Magnetic reconnection is a process that contributes significantly to plasma dynamics and energy transfer in a wide range of plasma and magnetic field regimes, including inertial confinement fusion experiments, stellar coronae, and compact, highly magnetized objects like neutron stars. Laboratory experiments in different regimes can help refine, expand, and test the applicability of theoretical models to describe reconnection. Laser-plasma experiments exploring magnetic reconnection at a moderate intensity (I-L similar to 10(14) W cm(-2)) have been performed previously, where the Biermann battery effect self-generates magnetic fields and the field dynamics studied using proton radiography. At high laser intensities ( IL lambda L2>1018Wcm-2 mu m2), relativistic surface currents and the time-varying electric sheath fields generate the azimuthal magnetic fields. Numerical modeling of these intensities has shown the conditions that within the magnetic field region can reach the threshold where the magnetic energy can exceed the rest mass energy such that sigma(cold)=B-2/(mu(0)n(e)m(e)c(2)) > 1 [A. E. Raymond et al., Phys. Rev. E 98, 043207 (2018)]. Presented here is the analysis of the proton radiography of a high-intensity (similar to 10(18) W cm(-2)) laser driven magnetic reconnection geometry. The path integrated magnetic fields are recovered using a field-reconstruction algorithm to quantify the field strengths, geometry, and evolution.