论文标题
大离子中性漂移速度和等离子加热在部分电离的冠状雨斑中
Large ion-neutral drift velocities and plasma heating in partially ionized coronal rain blobs
论文作者
论文摘要
在本文中，我们介绍了部分电离冠状雨斑的动力学的数值研究。我们使用两流体模型执行高分辨率的2D模拟，该模拟考虑了等离子体中包含的带电和中性颗粒之间的碰撞相互作用。我们遵循冷等离子体冷凝的演变，它通过等温垂直分层的气氛，代表了更热和较轻的太阳能电晕。我们研究了系统中存在的不同程度碰撞耦合的后果。一方面，我们发现在斑点的致密核心上，血浆的带电和中性成分的表现为单个流体，具有微不足道的漂移速度（几个cm s^-1）。另一方面，在斑点的边缘上，耦合较弱，更大的漂移速度（1 km s^-1的顺序）出现。另外，摩擦加热会在斑点和电晕之间的过渡层处引起大量温度升高。我们第一次表明，由于与冠状雨动力学相关的离子中性解耦，因此可以发展如此大的漂移速度和温度增强。这可能会导致在具有过渡区域温度的冠状雨水边界处的等离子体发射增强。
In this paper we present a numerical study of the dynamics of partially ionized coronal rain blobs. We use a two-fluid model to perform a high-resolution 2D simulation that takes into account the collisional interaction between the charged and neutral particles contained in the plasma. We follow the evolution of a cold plasma condensation as it falls through an isothermal vertically stratified atmosphere that represents the much hotter and lighter solar corona. We study the consequences of the different degrees of collisional coupling that are present in the system. On the one hand, we find that at the dense core of the blob there is a very strong coupling and the charged and neutral components of the plasma behave as a single fluid, with negligible drift velocities (of a few cm s^-1). On the other hand, at the edges of the blob the coupling is much weaker and larger drift velocities (of the order of 1 km s^-1) appear. In addition, frictional heating causes large increases of temperature at the transition layers between the blob and the corona. For the first time we show that such large drift velocities and temperature enhancements can develop as a consequence of ion-neutral decoupling associated to coronal rain dynamics. This can lead to enhanced emission coming from the plasma at the coronal rain-corona boundary, which possesses transition region temperature.
