Influence of Ion Irradiation on Critical Characteristics of Second-Generation HTSC Tapes

One of the practical applications of the second-generation HTSC tapes (or CC – coated conductors) is in accelerator magnets. During operation, the superconducting winding will inevitably be exposed to ionizing radiation with the formation of radiation defects in the HTSC layer. This process can lead to a gradual degradation of both the critical characteristics and the structure of the HTSC. The report presents the results demonstrating the change in the critical temperature and critical current (down to a complete loss of superconducting properties) of the second-generation HTSC tapes under irradiation with 6.3 MeV Cu ions in a wide range of fluences. The critical temperature was measured by a four-contact method. The critical current was calculated from the magnetization curves, which were measured in the temperature range from 5 to 77 K and magnetic fields up to 8 T. It was demonstrated that the critical current is more sensitive to radiation defects than the critical temperature is.