Experimental verification of the temperature and strain dependence of the critical properties in Nb3Sn wires

The critical current density in NbsSn conductors is described with an impro ved scaling formula for the temperature, magnetic field and strain dependen ce. In an earlier study it is concluded that the largest uncertainties in t his description arise from the temperature dependence that is described wit h various slightly different empirical relations. For the optimization of t he numerical codes, used to predict the stability of large magnet systems, a more accurate description is required. Therefore, two different bronze pr ocessed conductors for the ITER CS model coil are analyzed in detail, The c ritical current is measured at temperatures from 4.2 K up to the critical t emperature, in magnetic fields from 1 T to 13 T and with an applied axial s train from -0.6 % to +0.4 %, The axial strain is applied by a II-shaped ben ding spring and a comparison is made between brass and Ti-6Al-4V, as substr ate material.