The influence of disorder introduced by neutron irradiation is investigated for sintered bulk material and for in-situ iron sheathed wires. We find strong enhancements of the upper critical field and a decrease of the upper critical field anisotropy. Accordingly, the irreversibility fields, defined as the fields, where the first continuous superconducting current path occurs and the resistivity disappears, are enhanced. The critical current densities increase after irradiation, especially at high magnetic fields. This enhancement is mainly caused by the changes of the reversible properties, but slight changes in flux pinnning are observed as well.
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