MHD_NX: ideal MHD stability code on two-dimensional unstructured grids

The code developed by the authors for calculating the MHD stability of two-dimensional plasma configurations with an arbitrary magnetic field topology is presented. The choice of an appropriate version of the finite element method on hybrid unstructured computational grids and test calculations are discussed. Examples of using the code for modeling the plasma stability in Galatea traps and in divertor configurations of tokamak taking into account the plasma beyond the separatrix are given.