Updated Structural Assessment of the DTT Poloidal Field Coils

In the context of tokamak reactors, the Poloidal Field Coils (PFCs) are magnets that surround the Toroidal Field Coil (TFC) assembly and generate a magnetic field which equilibrates the plasma and shapes it into prescribed forms. To enforce plasma requirements, the six PFCs of the Divertor Tokamak Test (DTT), have been designed to reach a self-field as high as 9 T, and in operation will withstand electromagnetic loads of several tens of MN. From a mechanical point of view the PFCs are highly inter-connected components, whose structural response is influenced by their own loading conditions as well as by the TFC system they are installed onto. As the PFCs experience high time-varying vertical forces that would tend to separate the coils from the TFCs, a challenging task is attaining a robust design of their support structures. This work discusses some of the main design choices that have been made for the PF coil system of DTT, illustrating the in-operation behaviour and interaction among the TF coils, the PF supports and the PF magnets. Finite Element Analysis has been the principal, but not exclusive, means of investigation.