Low loss Nb-Ti superconducting Rutherford cable manufacture for the SIS 300 INFN model dipole

The INFN (Istituto Nazionale di Fisica Nucleare, Italy) has launched in 2006 the DISCORAP (DIpoli SuperCOnduttori RApidamente Pulsati, or fast-pulsed superconducting dipoles) project which foresees the design, manufacture and test of a fast cycled (1 T/s) 4.5 T, cosθ , dipole model for the SIS 300 synchrotron of the FAIR (Facility for Antiproton and Ion Research) facility at GSI (Darmstadt, Germany). This magnet is now close to completion at ASG company (Genova, Italy); it is based on a Rutherford cable, manufactured by Luvata Superconductors, which incorporates several technologies to reduce the AC losses, namely a Nb-Ti filament diameter around 3 μm, Cu 0.5wt%Mn interfilamentary matrix and a Rutherford cable with stainless steel core. The development of the Rutherford foresees two subsequent generations of Rutherford cables, aimed to reach the demanding goals of the SIS-300 specifications in steps. In this paper we present the results of the manufacture of the first generation Rutherford cable, and the assessment of its electromagnetic performances, including critical current density, twist pitch impact on critical current degradation, filament hysteresis and deformation, transverse resistivity, Cu-Mn paramagnetism.