Improvement of trapped field in DyBaCuO bulk by proton irradiation

► A post-manufacturing macro Jc control for cm sized bulk superconductor was studied. ► The irradiation of low-fluence 200MeV protons was performed on bulk DyBaCuO. ► The trapped fields were increased by up to 80% (1.2×1012protons/cm2). ► The macroscopic critical current density was increased at everywhere in sample. The possibility of the post-manufacturing control of the macroscopic critical current density by the low-fluence high-energy proton irradiation was studied for cm sized bulk high temperature superconductor. The irradiations of 200MeV protons on bulk DyBaCuO samples with the fluence of from 2.3×1010 to 1.2×1012protons/cm2 were performed. The maximum magnetic flux densities on the sample surfaces were increased by up to 80% after proton irradiation. This value of the increment is larger than the individual differences of the bulk high temperature superconductors just after the production. The macroscopic critical current densities seemed to be increased almost everywhere in the samples.