NUMERICAL-ANALYSIS OF A COUPLED PROBLEM - TIME EVOLUTION OF A TOKAMAKPLASMA IN CONTACT WITH A CONDUCTING WALL

In this paper we analyse the time evolution of a tokamak plasma after the failure of the vertical control system. In this case, the plasma e ventually touches the conducting wall and gives rise to currents which flow partly in the wall, partly in the plasma. We show how, under sim plifying assumptions, the problem can be analysed by means of pure ele ctromagnetic formulations. After a brief review of the state of the ar t in the analysis of this phenomenon, we propose and discuss three alt ernative Eulerian approaches: an evolutionary equilibrium formulation, a convection-diffusion model and a 3D error-based approach.