Numerical simulation of MHD processes in tokamaks

The motion of plasma in tokamaks is studied by numerical solution of two-(2D) and three-dimensional (3D) systems of MHD equations. The 2D model is based on the simplified Kadomtsev-Pogutse system of equations, which describes kink motions of incompressible plasma with finite conductivity in a strong longitudinal magnetic field. For the m=1 kink mode the dynamics of internal disruption is considered, for the mode m=2, the appearance and evolution of magnetic islands is studied. The 3D model uses the full system of MHD equations which includes effects of compressibility. The motion of individual modes in cylindrical and toroidal plasma has been studied. Some preliminary results on the interaction of different kink modes have been obtained. (author)