Investigation of magnetization behavior of Nb3Sn wires for the Next European Dipole (NED) activity

In the frame of the conductor development for the Next European Dipole (NED), magnetization measurements are an important tool for understanding the capability of a conductor to transport current. The measurement of the magnetic momentum in parallel and transverse field gives direct information about the content of Nb3Sn as well as other superconducting phases and about the critical current density. A well known problem related to high current Nb3Sn conductors is the presence of magnetic instabilities at low field limiting the transport properties. Through magnetization measurements the phenomena at the basis of instabilities (flux-jumps) due to strand magnetization can be analysed and related to different mechanisms (large filament diameter, filament coupling, etc.). Looking at our results, we believe that also the presence of unreacted Nb is a source of instability. Herewith, we will present and discuss the magnetization measurements carried out on the first strands manufactured according to NED conductor specifications.