The Effect of Proton Irradiation on the Critical Current of Commercially Produced YBCO Conductors

Samples of YBCO superconductor from two manufacturers were irradiated with protons at the BLIP facility at BNL. Two specimens of each type of conductor were irradiated to five fluences covering the range from 10 16 to 4 times10 17 protons/cm 2 . The beam parameters for the irradiations were 42 muA and 142 MeV. The critical current (zero field, 1 muV/cm) for all twenty samples was measured in liquid nitrogen before and after irradiation to quantify the effects of high-dose proton-induced radiation damage on the performance of the conductor, and thus evaluate its suitability for service in high-radiation environments. All of the specimens had a pre-irradiation current of about 100 A. This current decreased linearly with fluence, with a slope of about 20% per 10 17 protons/cm 2 . The agreement between the two samples of each brand of conductor was exceptional.