Structural analysis of DTT divertor PFU under electromagnetic and thermal loading

The plasma-facing units (PFU) of the Divertor Tokamak Test facility (DTT) are expected to withstand high heat fluxes as well as electromagnetic (EM) loads during normal and off-normal operations. As the design of the DTT divertor PFU moves forward, specific analyses of the component's real geometry under the expected loads are needed to verify its suitability. This paper presents structural analyses of the DTT divertor PFU under combined loads including EM, thermal and pressure loadings. A single PFU is analyzed under EM loads during the slow plasma Vertical Displacement Event (VDE), together with heat fluxes during single-null (SN) detached plasma configuration. A strategy for using a discrete vector field of EM loads as input data in the ABAQUS environment is described. Due to the rather large displacements obtained with EM loads and the original set of PFU supports, two additional supports are proposed and included in the analyses. The results with the additional supports show an improvement of the stresses and displacements. The analysis with combined loads reveals that the stresses in monoblocks, copper interlayer and weld regions are mainly driven by heat flux and pressure loads, while the EM loads are the source of higher (local) stresses in the CuCrZr pipe and supports.