Self-similar current sheet collapse triggered by "ideal" tearing
Self-similar current sheet collapse triggered by "ideal" tearing
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“理想”撕裂引发的自相似电流片塌陷
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
F. Pucci
中科院分区：
文献类型：
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作者：
A. Tenerani;M. Velli;A. Rappazzo;F. Pucci
我们通过“理想：撕裂模不稳定性在崩溃的电流片在高伦德奎斯特数（$Sgg10^4$）的快速重联的开始和演变进行了研究。随着坍缩的进行，快速重联早在斯威特-帕克型结构形成之前就被触发了：在初始不稳定性的线性阶段之后，X点坍缩和非线性的改革，一个“理想”撕裂模式的层次在越来越小的尺度上越来越快地重复。我们提出了一个简单的模型描述的自相似的演变，它解释了初始片的中断和随之而来的湍流谱的时间尺度。
We study the onset and evolution of fast reconnection via the "ideal: tearing mode instability within a collapsing current sheet at high Lundquist numbers ($Sgg10^4$). As the collapse proceeds, fast reconnection is triggered well before a Sweet-Parker type configuration can form: after the linear phase of the initial instability, X-points collapse and reform nonlinearly, a hierarchy of "ideal" tearing modes repeating faster and faster on current sheets at ever smaller scales. We present a simple model describing the self-similar evolution which explains both the timescale of the disruption of the initial sheet and the consequent turbulent spectra.