标题： 磁冕界面中考虑磁扩散的剪切流不稳定性的线性分析 显示英文标题

标题： Linear analysis of shear-flow instabilities in a prominence-corona interface with ambipolar diffusion

摘要： 观测表明太阳日珥中存在Kelvin-Helmholtz不稳定（KHi）。由于日珥等离子体的部分电离效应可能影响KHi的起始。我们研究了在界面模型中KHi的触发，该模型由一个部分电离的日珥区域和一个完全电离的日冕区域组成，并且有一个平行于界面的均匀磁场。日珥区域内存在纵向流动。等离子体是可压缩的，在日珥等离子体中考虑了双性扩散的作用，它反映了带电粒子与中性粒子之间的碰撞。我们推导出界面线性扰动的色散关系并进行了分析。对于实际的日珥参数获得了数值结果。我们发现，可压缩性和气压在决定不稳定流速方面很重要，特别是在与观测一致的次阿尔文流速范围内。双性扩散通常具有不稳定的效应，并降低了KHi起始的阈值流速。 显示英文摘要

摘要： Observations have shown the presence of the Kelvin-Helmholtz instability (KHi) in solar prominences. Effects due to partial ionization of the prominence plasma may influence the KHi onset. We study the triggering of the KHi in an interface model that consists of a partially ionized prominence region and a fully ionized coronal region, with a uniform magnetic field parallel to the interface. There is a longitudinal flow in the prominence region. The plasma is compressible and the role of ambipolar diffusion, which accounts for collisions between charges and neutrals, is taken into account in the prominence plasma. We derive the dispersion relation of linear perturbations on the interface and analyze some limit cases analytically. Numerical results are obtained for realistic prominence parameters. We find that compressibility and gas pressure are important in determining the unstable flow velocities, specially in the range of sub-Alfv\'enic flows that are consistent with the observations. The ambipolar diffusion has a generally destabilizing influence and reduces the threshold flow velocity for the KHi onset.