论文标题
在存在平衡电子温度各向异性的情况下，等离子体中磁性涡流链的线性稳定性
Linear stability of magnetic vortex chains in a plasma in the presence of equilibrium electron temperature anisotropy
论文作者
论文摘要
通过降低的流体模型，在分析二维中研究了等离子体中磁涡旋的线性稳定性，假设具有强的指导场并考虑了平衡电子温度各向异性。磁涡旋链是通过经典的“猫的眼睛”溶液建模的，并根据能量 - 西米尔方法来分析保守功能的第二个变化来研究线性稳定性。稳定性分析是在由涡流的分离界面的域上进行的。考虑了两种情况，对应于垂直平衡离子和电子温度之间的比率，分别远大于统一。在前一种情况下，平衡流取决于任意函数。如果平衡电子温度各向异性从上方和下方界定，则达到稳定性，其下限对应于防止火管不稳定性的状况。进一步的条件将涡流振幅的上限设置为平衡流的给定选择。对于冷离子，必须考虑两个子箱。在第一个中，平衡对应于速度场与局部alfvén速度成正比的均衡。稳定性条件暗示：流动幅度的上限自动意味着消防稳定性，上限在电子温度各向异性上，并且在涡流尺寸上再次绑在上限上。第二个子箱是指在磁通量表面上不变的平衡静电电势，所得的稳定性条件对应于在没有流动的情况下对第一子盘的稳定条件。
The linear stability of chains of magnetic vortices in a plasma is investigated analytically in two dimensions by means of a reduced fluid model assuming a strong guide field and accounting for equilibrium electron temperature anisotropy. The chain of magnetic vortices is modelled by means of the classical "cat's eyes" solutions and the linear stability is studied by analysing the second variation of a conserved functional, according to the Energy-Casimir method. The stability analysis is carried out on the domain bounded by the separatrices of the vortices. Two cases are considered, corresponding to a ratio between perpendicular equilibrium ion and electron temperature much greater or much less than unity, respectively. In the former case, equilibrium flows depend on an arbitrary function. Stability is attained if the equilibrium electron temperature anisotropy is bounded from above and from below, with the lower bound corresponding to the condition preventing the firehose instability. A further condition sets an upper limit to the amplitude of the vortices, for a given choice of the equilibrium flow. For cold ions, two sub-cases have to be considered. In the first one, equilibria correspond to those for which the velocity field is proportional to the local Alfvén velocity. Stability conditions imply: an upper limit on the amplitude of the flow, which automatically implies firehose stability, an upper bound on the electron temperature anisotropy and again an upper bound on the size of the vortices. The second sub-case refers to equilibrium electrostatic potentials which are not constant on magnetic flux surfaces and the resulting stability conditions correspond to those of the first sub-case in the absence of flow.
