Long-Range Atomic Order, Crystallographical Changes and Strain Sensitivity of Jc in Wires Based on Nb3Sn and Other A15 Type Compounds

The search for the reasons of the strain sensitivity in Nb3Sn multifilamentary wires is one of the most interesting problems encountered in A15 type compounds. The question is of considerable technical interest in view of using Nb3Sn (or V3Ga) wires in large superconducting magnets with fields well above 15 T. In the last years, the attempts to understand the correlation between the critical current density, Jc, (or the critical current, Ic) and the applied strain, e, have led to a considerable progress in the knowledge of the fundamental properties of A15 compounds.