测地声模的扰动磁场与扰动磁矢分析

The Magnetic Field and Vector of Geodesic Acoustic Mode

测地声模是经典的静电振荡,通常的处理方法忽略了其磁场扰动,但严格的磁流体力学分析表明,磁场扰动在β量级。该文从理想磁流体力学方程组出发,通过严格的线性分析,得到了测地声模激发期间,扰动磁场及对应的扰动磁矢的表达式,并与回旋动理学下的结果进行比对。

Using ideal magnetohydrodynamic equations, the magnetic component of geodesic acoustic mode was investigated analytically. It is found that the parallel component of the magnetic vector is on the same order of the poloidal component, which means the perpendicular projection of magnetic vector cannot be disregarded without any further consideration. It is shown that the radial magnetic vector is much less than the poloidal one and can be ignored directly.