Temperature dependence of the trapped field and mechanical properties of neutron irradiated and reinforced YBa₂Cu₃O_7-δ bulk superconductors

We report on the temperature dependence of the trapped field in neutron irradiated YBa₂Cu₃O_7-δ bulk melt-textured materials. The field trapping capability of these materials at' low temperatures is limited by their mechanical properties. We observe that samples without reinforcement usually break during activation at temperatures of around 50 K. Two reinforcement techniques were tested. Resin impregnation is found to be less effective than stainless steel bandaging to compensate for the magnetic stress generated during activation. The resin impregnated samples crack during activation at temperatures of around 45 K. Stainless steel bandaging improves the mechanical properties of the YBa₂Cu₃O_7-δ samples and trapped fields of up to 13.3 T were achieved at 33 K.