Modeling of AC Losses in DEMO RW2rutstab Conductor

The AC loss in the react&wind DEMO TF prototype conductor RW2rutstab were measured in SULTAN at the end of 2019. These tests were modelled with the THELMA code, making use of a detailed geometric cable description. The inter-strand contact conductances are computed starting from the strand trajectories, their diameters and a set of contact specific conductivities individually assigned to the strands. Different criteria to assign these conductivities have been considered. Starting from the model parameters identified through the simulation of AC loss tests performed with a sinusoidal field perpendicular to the cable broad face, tests performed with the cable rotated by 90°, sinusoidal field were also modelled. The AC losses in the presence of a magnetic field varying in time with a trapezoidal cycle were studied as well. The article describes the utilized models and discusses in detail the obtained results.