An Optimization of a NbTi Wire Cross Section to Attain Low AC-Losses and High Critical Current

Removing the heat generated by AC-losses in large-scale superconducting applications has high costs. This is also the case in semi-DC magnets such as the ones of large particle accelerators where magnets are ramped synchronously with the beam energy. Also, these magnets require large cables made of several individual strands. This makes even the AC-loss analysis of such magnets very difficult. However, to attain low-loss full-size magnets, it becomes necessary to use wire designs that provide low AC-losses and adequate stability. The design of individual wires includes at least the determination of filament sizes and locations and the selection of matrix material. At the same time a high critical current and good workability must be ensured. With numerical analysis it is possible to consider these factors and design new strands and cables having low AC-losses for specific applications. In this paper we consider how to employ a numerical tool for the optimization of the NbTi wire cross-section to achieve low AC-loss and high I_c.