论文标题
动力学 - alfvén波湍流中的间歇性和电子加热
Intermittency and electron heating in kinetic-Alfvén-wave turbulence
论文作者
论文摘要
我们报告了低β等离子体中亚离子级湍流的分析和数值研究，重点介绍了波动和电子加热的光谱特性。在等温限制中，数值结果强烈支持对湍流的描述，描述是一种含量均衡的Kolmogorov样动物Alfvén波波动的级联，由Boldyreve＆Perez修订（Astrophys。J.Lett。758，L44（2012）），以包含Intermittent效果。当去除等温度的限制（即，包含电子动力学物理学）时，由于电子兰道抑制作用而发现能量光谱会陡峭，这是由于电流板周围的局部较弱的非线性减弱而启用的，并通过速食空间级数产生大量的能量消散。使用HERMITE - 分解表示表达电子分布函数的速度空间依赖性，使我们能够为分布的Hermite矩获得一个分析，最低的溶液，该溶液通过数值模拟而表现出来。
We report analytical and numerical investigations of sub-ion-scale turbulence in low-beta plasmas, focusing on the spectral properties of the fluctuations and electron heating. In the isothermal limit, the numerical results strongly support a description of the turbulence as a critically-balanced Kolmogorov-like cascade of kinetic Alfvén wave fluctuations, as amended by Boldyrev & Perez (Astrophys. J. Lett. 758, L44 (2012)) to include intermittent effects. When the constraint of isothermality is removed (i.e., with the inclusion of electron kinetic physics), the energy spectrum is found to steepen due to electron Landau damping, which is enabled by the local weakening of advective nonlinearities around current sheets, and yields significant energy dissipation via a velocity-space cascade. The use of a Hermite-polynomial representation to express the velocity-space dependence of the electron distribution function allows us to obtain an analytical, lowest-order solution for the Hermite moments of the distribution, which is borne out by numerical simulations.
