An Application of the Mercier Criterion to a Tokamak Plasma with an Elliptical Cross Section

Abstract

Magnetohydrodynamic (MHD) stability of an axially symmetric plasma is studied by use of the Mercier criterion. By introducing a non-orthogonal coordinate system, the Mercier criterion is presented in a form easy to apply. The criterion is applied to a tokamak plasma with an elliptical cross section. It yields a necessary criterion for stability, which reduces to the Shafranov-Yurchenko formula in the case of a circular cross section.