Superconducting Layer Structure and Current-Carrying Capacity of Nb3Sn-Based Composites and the Effect of High Pressure on Nb3Sn Superconductivity

The paper presents the overview reflecting the current state of the development of low-temperature Nb3Sn-based superconductors and their place in high-energy physics. Modern methods of manufacturing Nb3Sn-based multifilamentary wires designed to create strong magnetic fields are described indicating their main advantages and disadvantages. Based on the available literature data and the in-house research of the authors of present review, the effect of composite construction, their composition, and heat treatment modes on the structure of superconducting layers and the current-carrying capacity of conductors are analyzed. Particular attention is paid to establishing a quantitative relationship between structural parameters and the pinning force to assess the prospects for optimizing the structure and achieving the maximum possible critical current density in strong magnetic fields. In addition, the paper presents a brief review of publications on the effect of high hydrostatic pressures on the main parameters of the superconducting state of the Nb3Sn compound.