Analysis of the nuclear heating of the superconducting toroidal field coils in DEMO

Reducing the nuclear loads in the toroidal field (TF) coils is a main driver to the integrated design of the DEMO tokamak. Problems may arise from local peak values of nuclear heating in the winding packs, as well as neutron fluence and irradiation damage on the epoxy insulator and the copper stabilizer. In particular, the integration of various systems into the different vacuum vessel ports must consider in each design step the shielding of neutrons generated by the fusion plasma with the objective to limit radiation loads to below specific design limits. The pre-conceptual phase of the EU DEMO development is concluding in 2020 and the design of all essential ports have reached sufficient maturity to allow a first global assessment of the nuclear loads expected in TF coils. The analyses can thus also take into account the cross-talk between different ports. The results are compared to the radiation limits defined for the DEMO TF coils at the beginning of the pre-conceptual phase. Furthermore, the results will guide future work on shielding design and inform designers of systems yet to be integrated into DEMO of promising shielding strategies.