Estimation of the power dissipation on the casing of DTT toroidal field coil during a fast plasma disruption

•The magnet system of the Divertor Tokamak Test facility is mainly made up with superconducting coils.•The amount of Joule heat produced by the induced eddy currents on the passive structures and Toroidal Field Coil casing must be removed.•Among the magnetic field sources of interest, the uncontrolled event in which the plasma current goes to zero from its maximum value in milliseconds timescale, is expected to be the most critical in terms of the deposited thermal energy on the surrounding structures.•The losses assessment is then important for a correct design. The aim of this paper is the computation of the power dissipated on the Toroidal Field Coil (TFC) casing of the Divertor Tokamak Test facility (DTT). The DTT Tokamak will be installed in Fascati (Italy), and is in an advanced design stage. The magnetic system will be realized with superconducting coils so that the correct dimensioning of the cooling system is mandatory. As a consequence, a detailed knowledge of the main sources of dissipation is required. Our attention will here be focused on the TFC casing and, in particular, on the dissipations due to the eddy currents induced on the casing by time-varying magnetic field during a Fast Plasma Disruption (FPD). A finite element model whose geometry has partly been imported into Ansys 2021/R2 SpaceClaim (TFC casing), and partly made in Ansys 2021/R2 DesignModeler (plasma, Vacuum Vessel (VV) and Stabilizing Plates (SP)), has been implemented in Ansys 2021/R2 Maxwell 3D to perform a transient analysis of the FPD event. The current induced on the TFC casing, as well as the total power losses, are the output of our computation to be used for the cooling system dimensioning. In order to estimate the heat rate to be removed during normal operation, the breakdown and Single Null (SN) scenarios have also been studied.