Doubling of the Critical Current Density of 2G-YBCO Coated Conductors through proton irradiation

We report on magnetization and transport measurements of the critical current density of commercial 2G YBCO coated conductors before and after proton irradiation. The samples were irradiated along the c-axis with 4 MeV protons to a fluence of 1.5x10$^{\mathrm{16}}$ p/cm$^{\mathrm{2}}$. We find that at temperatures below 50 K, proton irradiation increases J$_{\mathrm{c}}$ by a factor of 2 in low fields and increases up to 2.5 in fields of 7 T. At 77 K, proton irradiation is less effective in enhancing the critical current. Doubling of J$_{\mathrm{c}}$ in fields of several Tesla and at temperatures below 50 K will be highly beneficial for applications of coated conductors in rotating machinery, generators and magnet coils. - Work supported by the US DoE-BES funded Energy Frontier Research Center (YJ), and by Department of Energy, Office of Science, Office of Basic Energy Sciences (UW, WKK), under Contract No. DE-AC02-06CH11357.