Damping effect on the ITER vacuum vessel displacements during slow downward locked and rotating asymmetric vertical displacement events

In this paper, we present the electromechanical coupled analysis of the ITER vacuum vessel in case of slow downward locked and rotating Asymmetric VDEs. The numerical model for simulating the AVDE includes the asymmetric distribution of the halo currents obtained by a suitable 3D kink perturbation of a slow VDE downward computed by the 2D code DINA. In the case of a rotational AVDE, the rotation frequency of the kink asymmetry has been chosen to be ω = 2π × 5 rad/s. The model includes the mesh of the main passive components facing the plasma. The whole torus (360 degrees) has been discretized. It is shown that the very high complexity of the numerical model can be suitably treated. The strength of the sideways force here computed is comparable with previous estimates. The damping effect due to the interaction with the external field is evaluated showing a positive mitigation of the mechanical oscillations of the vessel during the electromagnetic transients