Phase mixing of Alfven waves in axisymmetric non-reflective magnetic ´ plasma configurations
Phase mixing of Alfven waves in axisymmetric non-reflective magnetic ´ plasma configurations
复制标题
轴对称非反射磁等离子体配置中阿尔文波的相位混合
DOI：
10.1093/mnras/stx2914
复制
发表时间：
2018
影响因子：
4.8
通讯作者：
E. Shurgalina
中科院分区：
文献类型：
--
作者：
N. Petrukhin;M. Ruderman;E. Shurgalina
我们研究在非反射轴对称磁等离子体配置中传播的相位混合阿尔文波的阻尼。我们推导出描述阿尔芬波振幅衰减的一般方程。然后我们将一般理论应用于具有指数发散磁场线的特定情况。该结构不反射的条件决定了等离子体密度沿磁场线的变化。随着高度呈指数下降的密度分布不属于非反射密度分布。然而，我们设法找到了非常接近指数递减密度的非反射轮廓。我们计算了不同剪切粘度值下总波浪能通量随高度的变化。我们发现，为了在下日冕处消散大量的波能，与经典等离子体理论给出的值相比，需要将剪切粘度增加七个数量级。我们获得的一个重要结果是，波阻尼的效率很大程度上取决于密度随高度的变化。密度下降越强，波阻尼越弱。在此结果的基础上，我们提出了对具有指数发散磁场线的平衡配置中增强波阻尼现象的物理解释。
We study damping of phase-mixed Alfvén waves propagating in non-reflective axisymmetric magnetic plasma configurations. We derive the general equation describing the attenuation of the Alfvén wave amplitude. Then we applied the general theory to a particular case with the exponentially divergent magnetic field lines. The condition that the configuration is nonreflective determines the variation of the plasma density along the magnetic field lines. The density profiles exponentially decreasing with the height are not among non-reflective density profiles. However, we managed to find non-reflective profiles that fairly well approximate exponentially decreasing density. We calculate the variation of the total wave energy flux with the height for various values of shear viscosity. We found that to have a substantial amount of wave energy dissipated at the lower corona, one needs to increase shear viscosity by seven orders of magnitude in comparison with the value given by the classical plasma theory. An important result that we obtained is that the efficiency of the wave damping strongly depends on the density variation with the height. The stronger the density decrease, the weaker the wave damping is. On the basis of this result, we suggested a physical explanation of the phenomenon of the enhanced wave damping in equilibrium configurations with exponentially diverging magnetic field lines.
在分层和发散的日冕结构中传播的阿尔文波的增强相位混合
影响因子：
6.5
作者：
Smith P
通讯作者：
Smith P