Towards the simulation of DEMO VDEs with JOREK

Disruptions reduce the lifetime of future fusion machines. In view of building a "DEMOnstration fusion power plant" (DEMO), a solid physics basis of plasma disruptions has to be developed.

In consonance with the “European DEMO team” within the ambit of the “EUROfusion program” we use a possible plasma DEMO scenario to perform numerical simulations with the well validated code JOREK-STARWALL. We aim to contribute to a robust design of an European DEMO by studying the effects on the machine of a loss of vertical control and by proposing possible mitigation schemes. We investigate primarily unmitigated vertical displacement events (VDE). Their presence can threaten the integrity of the machine by causing large mechanical forces onto the plasma facing components and by applying large heat loads during the thermal quench (TQ) and current quench (CQ). In an attempt to predict the effects of a loss of vertical plasma control, we show for the first time, results of 3D DEMO simulations with JOREK-STARWALL, to gain insights into the temporal length of the TQ and to predict the maximum vertical force applied to the machine wall. In addition, we discuss further insights offered by 2D simulations. Through them, we estimate the reduction of the global vertical forces on the plasma facing components by injecting impurities (Neon). As mitigated disruptions can form a beam of runaway-electrons (REs), their impact on the sacrificial limiter and plasma facing components is studied accounting for the self-consistent interaction between fluid REs and 3D MHD dynamics.