Tensile strain dependence of critical current of RHQ-Nb3Al wires

Abstract Nb 3 Al superconducting wires produced by rapid heating and quenching (RHQ) have been developed for high-field accelerator magnets. It is known that critical currents of A15 superconductors (e.g., Nb 3 Al and Nb 3 Sn) have a dependence on stress/strain. It is thus important to clarify the stress/strain behavior of the RHQ-Nb 3 Al wires for the development of high-field accelerator magnets. We recently started experimentally investigating the strain dependence of the critical current of the RHQ-Nb 3 Al wires with a Ta interfilament by measuring their critical currents under longitudinal tensile strains. To evaluate the effect of residual strain in Nb 3 Al filaments induced by thermal contraction of the materials in the wire, neutron diffraction measurements were performed at room temperature.