Forces between plasma, vessel and TF coils during AVDEs at JET

In JET, during some vertical displacement events (VDEs), the plasma current and position are toroidally asymmetric. These events are referred to as asymmetric VDEs (AVDEs). Analysis of the interactions among the current carrying systems reveals that the repelling force between the plasma and the vessel is of little significance in asymmetric events, even if it is the main symmetric repelling force. The sideways force acting on the vessel is shown to be due mainly to the interaction with the toroidal field of the asymmetric circulation of currents in the wall. The asymmetric current path in the vessel is then calculated analytically for a simplified geometry and used together with experimental data to estimate the sideways force on the vessel.