2002 年 78 巻 9 号 p. 913-924
An introductory review is given on recent developments in the methods for stability analysis of a toroidally confined plasma. Emphasis is put on the perturbation analysis of a magnetohydrodynamic system that has the marginally stable state as a terminal point of continuous spectra. We address ourselves to the asymptotic matching method pertinent to such a problem. The Newcomb equation and inner layer equations are essential ingredients in the methods and the numerical methods for solving them are discussed.