Understanding how REBCO-based coated conductors (CC) are affected by neutron irradiation during service in the magnets of a tokamak power plant is key to optimising plant design and cost. This will require establishing a reliable and cheaper ion irradiation protocol on commercially available REBCO CC as a proxy to replace expensive neutron irradiation campaigns. In this work, 20 MeV oxygen ions combined with a pyramidal ridge style energy filter are used to irradiate several types of REBCO CC for comparison with neutron irradiation experiments, and to measure the response of each sample type to irradiation. The critical temperature ( T c ), critical current density ( J c ) and flux flow exponent ( n ) were all measured at varying temperatures ( T ) and magnetic fields applied perpendicular to the tape plane ( ) as irradiation damage ( ф ) is accumulated in steps up to and beyond the damage levels relevant to fusion power plant operating parameters. Our results on the changes in T c , high-field J c and n-values with oxygen irradiation show similar trajectories to published data on neutron irradiation, suggesting that filtered ion irradiation could be a good proxy for neutron irradiation of REBCO. Our results showed that T c decreased linearly with increasing damage, but YBCO CC declined at a slower rate compared to (Gd,Y)BCO and EuBCO CC. The n- values also decreased linearly with increasing damage at a faster rate than T c , suggesting irradiation effects REBCO superfluid density. Self-field J c , the accommodation field ( B α ) and high-field J c all change with ф following a trajectory that is well-fitted using an empirical equation containing terms describing an increase in flux pinning efficiency combined with an exponential decay term to model the degradation due to faster flux creep and a decreasing depairing current. • REBCO coated conductors subjected to energy-filtered oxygen ion irradiation • Superconducting properties tracked as a function of damage level • and n -values decrease linearly with damage, like neutron irradiation • Effect of irradiation on self-field critical current density and -values examined • Energy-filtered oxygen ion irradiation offers a reliable proxy for neutron irradiation
Iliffe et al. (Wed,) studied this question.