The strain and temperature scaling law for the critical current density of a jelly-roll Nb sub(3)Al strand in high magnetic fields

The measurements of engineering critical current density and upper critical field on a technological Nb sub(3)Al conductor were studied in magnetic fields up to 15 T, temperatures from 4.2 K up to the critical temperature and in the strain range from -1.79% to 0.67%. It was observed that at low currents the shape of the resistivity curve is only weakly dependent on the sample current. The results showed that high fields (J sub(E)) is not dependent on grain-size, consistent with J sub(E)-microstructure correlations in other superconducting materials.