带奇异电流密度面无力磁场及其稳定性

FORCE-FREE MAGNETIC FIELDS WITH SINGULAR CURRENT DENSITY SURFACES AND THEIR STABILITY

从Bernstein磁流体力学能量原理出发,讨论圆柱坐标下一类带奇异电流密度面的一维单参数无力磁场的稳定性.这类无力磁场在参数空间同时存在稳定区和不稳定区,其稳定性完全由磁螺距在圆柱轴邻域内的径向分布决定,与位于磁场边界处的奇异电流密度面无关.

Starting from the Bernstein's hydromagnetic energy principle, a general analysis is presented on the stability of a kind of one-dimensional force-free magnetic fields with singular current density surfaces and a single parameter in the cylindrical coordinates. The results obtained show that there exist stable and unstable regions in the parameter space. Their stability is determined solely by the radial distribution of the magnetic pitch in the neighborhood of the cylindrical axis, and irrelevant to the presence of the singular current density surface at the boundary.