Unlocking the performance evolution of GdBCO coated conductors irradiated by deuterium plasma

Abstract

Abstract REBa2Cu3O7-δ (REBCO, RE: rare earth) coated conductors (CCs) can generate a powerful magnetic field and are optimal for sustaining the reaction in fusion devices. However, the REBCO CCs will inevitably be exposed to neutron radiation during device operation. Transmutation produces gas atoms such as hydrogen will affect their properties. In this paper, GdBCO CCs were irradiated by 20 eV deuterium plasma. It was found that the irradiation introduced smaller (2-4 nm) pinning sites that formed a mixed pinning landscape with rare earth oxides (tens of nanometres) in the pristine samples, leading to an improved vortex pinning. At an irradiation fluence of 5.0 × 1018 D/cm2, the Jc values of the samples irradiated by deuterium can maintain an about 30% enhancement of in-field performance at 4.2 K. Excess irradiation results in a decrease in Jc, a broadening of the superconducting transition width, and an enhanced disorder in GdBCO. This study provides some valuable insights for potential changes in the properties of REBCO CCs irradiated in fusion devices.