Suydam不稳定性的增长率

Growth rate of the Suydam instability

证明了用能量原理推导出的关于圆柱等离子体局部模的Suydam不稳定性,对应的动能变化量趋于无穷大,故其增长率趋于零。通过对Hain-Lust方程求解知道,Suydam不稳定性的真实物理意义是,它对应于一系列低模数的广域不稳定模,其增长率随模数加大而减小。实际上,任何扭曲模分析都一定要正确处理共振面附近的求解问题。提出了不满足Suydam判据时外扭曲模的一个求解方法。

It is shown that the variation of the kinetic energy for Suydam instability of a cylindrical plasma derived from the energy principle is infinite, implying that the growth rate of such instability is zero. Realistic physical meaning of the Suydam instability can be correctly explained by the solution of the Hain-Lust equations. Accomplished works so far are simply commented. Finally, a method is suggested to determine the stability of the externally kink modes for a tokamak plasma when in its internal region the Suydam criterion is unsatisfied.