Neutron irradiation of coated conductors

Various commercial coated conductors were irradiated with fast neutrons in order to introduce randomly distributed, uncorrelated defects which increase the critical current density, J c , in a wide temperature and field range. The J c -anisotropy is significantly reduced and the angular dependence of J c does not obey the anisotropic scaling approach. These defects enhance the irreversibility line in not fully optimized tapes, but they do not in state-of-the-art conductors. Neutron irradiation provides a clear distinction between the low field region, where J c is limited by the grain boundaries, and the high field region, where depinning leads to dissipation.