Calculation of eddy currents and magnetic forces in nuclear fusion experiments

Tokamaks are toroidal experimental devices in which it is being attempted to achieve controlled nuclear fusion. This report describes investigations of the magnetic field diffusion through the vacuum vessel of the ASDEX Upgrade tokamak that occurs when there is sudden disruption of the plasma current. The eddy currents thereby generated in the vessel wall are numerically analysed in respect of their time behaviour and distribution. The vessel is also permeated by various magnetic fields, which, in conjunction with the eddy currents, produce magnetic forces. These forces are likewise calculated since they have a bearing on the design of the vessel. (orig.)