THE DISSIPATION OF SOLAR WIND TURBULENT FLUCTUATIONS AT ELECTRON SCALES
THE DISSIPATION OF SOLAR WIND TURBULENT FLUCTUATIONS AT ELECTRON SCALES
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DOI：
10.1088/0004-637x/730/2/114
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发表时间：
2011-04-01
影响因子：
4.9
通讯作者：
Burgess, David
中科院分区：
文献类型：
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作者：
Camporeale, Enrico;Burgess, David
我们提出了二维完全动力学的粒子在电池中的衰减电磁波动的模拟。计算箱是这样的，波长范围从电子到离子的陀螺半径被分解。所使用的参数对于太阳风来说是真实的，离子与电子的质量比是物理的。小尺度湍流波动的耗散被认为是太阳风加速和日冕加热的关键机制。计算结果表明，幂律级联的磁波动可以持续到电子拉莫尔半径的尺度，甚至更小。根据弗拉索夫线性理论对模拟结果进行了分析，并对粒子加热进行了评述。在这种状态下，轻阻尼模式的色散曲线表明，在电子尺度上观察到的功率谱陡增可能是线性机制造成的，但不可能将湍流波动直接识别为线性模式的集合。
We present two-dimensional fully kinetic particle-in-cell simulations of decaying electromagnetic fluctuations. The computational box is such that wavelengths ranging from electron to ion gyroradii are resolved. The parameters used are realistic for the solar wind, and the ion-to-electron mass ratio is physical. The dissipation of turbulent fluctuations at small scales is thought to be a crucial mechanism for solar wind acceleration and coronal heating. The computational results suggest that a power-law cascade of magnetic fluctuations could be sustained up to scales of the electron Larmor radius and smaller. We analyze the simulation results in light of the Vlasov linear theory, and we comment on the particle heating. The dispersion curves of lightly damped modes in this regime suggest that a linear mechanism could be responsible for the observed steepening of power spectra at electron scales, but a straightforward identification of turbulent fluctuations as an ensemble of linear modes is not possible.