Study of a 5 T research dipole insert-magnet using an anisotropic ReBCO Roebel cable

A design study is presented for the coil layout of the EUCARD-2 Five Tesla HTS Research (FeaTHeR) magnet. The angular dependence of the critical current in the used ReBCO Roebel cable is taken into account. This leads to a new coil layout named aligned block. This layout makes optimal use of the anisotropy of the ReBCO coated conductor, by aligning all tapes with the magnetic field lines. Both two-dimensional cross sections and three-dimensional coil layouts are presented. In the layouts the magnetic field angle is highest at the edges of the cable causing a large variation of the critical current over its width. Different approaches to the calculation of the critical current, with and without current sharing in and between the tapes, are presented. The values are compared to the values found using a non-linear network model of the cable, in which the electrical properties of the elements are calculated as a function of magnetic field and magnetic field angle. The model also includes electrical contact between the strands using additional network elements.