Losses in electrodynamic transient in superconducting Rutherford cables

The implementation of a continuum model for the simulation of interstrand coupling currents and the corresponding AC losses in superconducting Rutherford cables, due to electrodynamic transients, is performed. To obtain the necessary level of detail, the electrical model takes into account possible longitudinal variations of the contact conductance. A convergence study is performed to derive the minimum number of mesh elements required. The model is validated comparing loss values per cable twist pitch with the ones obtained through analytical formulae present in literature; an excellent agreement is found. Conclusions are drawn regarding the choice of the boundary conditions and the minimum length of the cable sample, to simulate the behavior of real long cables. In order to suppress losses, a resistive core is inserted in the cable and this strategy is implemented in the model. Induced currents and losses distributions in cables with core are derived and compared with the uncored case; conclusions are drawn about the choice of core width, placement and electrical resistance, to maximize its effect. The model presented is suitable to simulate cables behavior with or without core and subjected to uniform time-varying magnetic fields, considering different geometrical and electrical characteristic.