Electromagnetic effects induced by plasma disruptions in the NET vacuum vessel

The paper aims to give a contribution to the critical issue of the plasma disruptions in the next generation large tokamaks. In this framework the electromagnetic effects occurring in the vacuum vessel structure proposed for NET-I are predicted by means of a 3-D eddy current code. Typical disruption scenarios are considered, including plasma current decays preceeded by radial or vertical motions. The mesh used for the computations includes vacuum vessel, poloidal field coils and a toroidally segmented outboard first wall. The main results of the analysis (time history of toroidal current, forces and torques on the vessel, forces on the first wall, magnetic field on P.F. coils, etc.) are summarized. Comments and physical interpretations are of general type and therefore applicable to other devices (e.g. NET-II, ITER); in this respect a simple scaling with the plasma current is provided.