A phenomenological model on the kink mode threshold varying with the inclination of sheath boundary
A phenomenological model on the kink mode threshold varying with the inclination of sheath boundary
复制标题
扭结模态阈值随鞘层边界倾角变化的唯象模型
DOI：
10.1063/1.4829431
复制
发表时间：
2013
影响因子：
2.2
通讯作者：
T. Weber
中科院分区：
文献类型：
--
作者：
X. Sun;T. Intrator;M. Liu;J. Sears;T. Weber
在自然界和许多实验室等离子体中，由电流或磁绳穿入的磁通管在边界上有一个脚点。电流驱动扭结模是等离子体中最基本的理想磁流体不稳定性之一。它有一个不稳定性阈值，已被发现强烈依赖于边界条件(BCS)。我们提供了一个理论模型来解释这种阈值依赖在非在线约束边界条件和线约束边界条件之间的转换。我们使用实验测量的等离子体数据来评估模型参数，显式地验证了几个扭结特征函数，并验证了跨越NLT和LT BCS范围的边界条件BCS的模型预测。在该模型的基础上，可以在已知磁通绳端位移的情况下估计磁通绳端的扭结阈值，或者相反地，根据已知的磁通绳端的扭结稳定阈值来估计磁通绳端的运动。
In nature and many laboratory plasmas, a magnetic flux tube threaded by current or a flux rope has a footpoint at a boundary. The current driven kink mode is one of the fundamental ideal magnetohydrodynamic instabilities in plasmas. It has an instability threshold that has been found to strongly depend on boundary conditions (BCs). We provide a theoretical model to explain the transition of this threshold dependence between nonline tied and line tied boundary conditions. We evaluate model parameters using experimentally measured plasma data, explicitly verify several kink eigenfunctions, and validate the model predictions for boundary conditions BCs that span the range between NLT and LT BCs. Based on this model, one could estimate the kink threshold given knowledge of the displacement of a flux rope end, or conversely estimate flux rope end motion based on knowledge of it kink stability threshold.