Instability-driven electromagnetic fields in coronal plasmasa)
Instability-driven electromagnetic fields in coronal plasmasa)
复制标题
日冕等离子体中不稳定驱动的电磁场a)
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
D. Meyerhofer
中科院分区：
文献类型：
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作者：
M. Manuel;C. Li;F. Séguin;N. Sinenian;J. Frenje;D. Casey;R. Petrasso;J. Hager;R. Betti;Suxing Hu;J. Delettrez;D. Meyerhofer
以前在激光驱动球形靶的日冕中观察到的丝状电磁场[F. H.塞甘等人，物理。血浆。19，012701（2012）]在激光照射的塑料箱中进行了进一步研究。正面质子射线照相术提供了这些细丝的轴向视图，并显示了连贯的细胞结构，无论初始箔表面条件如何。所观察到的细胞场在整个等离子体演化过程中具有近似恒定的尺度大小，为210 μm。可能的场产生机制的讨论提供，它表明，细胞场结构的可能来源是磁热不稳定性。使用预测的温度和密度分布，这种不稳定性的增长最快的模式被发现是缓慢变化的时间和所观察到的细胞大小一致。
Filamentary electromagnetic fields previously observed in the coronae of laser-driven spherical targets [F. H. Seguin et al., Phys. Plasma. 19, 012701 (2012)] have been further investigated in laser-irradiated plastic foils. Face-on proton-radiography provides an axial view of these filaments and shows coherent cellular structure regardless of initial foil-surface conditions. The observed cellular fields are shown to have an approximately constant scale size of ∼210 μm throughout the plasma evolution. A discussion of possible field-generation mechanisms is provided and it is demonstrated that the likely source of the cellular field structure is the magnetothermal instability. Using predicted temperature and density profiles, the fastest growing modes of this instability were found to be slowly varying in time and consistent with the observed cellular size.