We developed new codes based on an extended MHD model including neoclassical viscosity effect, FLR effect, a finite resistivity shell and magnetic coils are integrated in our MHD code. By using these codes, we investigated magnetic island growth by an external perturbation and the nonlinear response between an external perturbation and magnetic island. It was found that electron orbit becomes stochastic without stochasticity of magnetic field by integrating a toroidal reduced MHD code and a particle code.
In this research project, we developed integrated nonlinear MHD/fluid type models and codes including physics models, for example, external magnetic perturbation, generation of runaway electron current inside core plasma, magnetic reconnection, magnetic island growth and the effect of impurity, which are necessary for investigate the major disruption of tokamak plasmas.