Strain Effect on Critical Current of Practical Superconductivity Wires under High Magnetic Field

为了使超导技术充分产业化，必须解决应力/应变问题，提高临界电流，加强实用超导导线的性能。利用量子束技术，成功地直接测量了Nb_3Sn、BSCCO和YBCO导线超导元件的热应变和晶格应变。在了解局部应变的基础上，研究临界电流对磁场、偏应变、晶界弱环节和微孪晶的应变依赖关系和标度规律成为可能。进一步提出了实际复合超导导线的局部应变和强度的计算方法。

In order to industrialize fully the superconductivity technology, it is indispensable to solve the stress/strain problems for improving the critical current and strengthening the practical superconducting wires. It has been succeeded to measure directly the thermal strain as well as lattice strain exerted on superconducting components of Nb_3Sn, BSCCO and YBCO wires by means of quantum beam techniques. On the basis of knowledge of local strains, it becomes possible to investigate the strain dependence and scaling rule of critical currents with respect to magnetic field, deviatoric strain, grain boundary weak link and micro-twin. Further the calculation methods have been proposed for the local strain and the strength of the practical composite superconducting wires.