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

为了使超导技术完全产业化，必须解决超导线材的应力/应变问题，以提高超导线材的临界电流，强化实用超导线材。用量子束技术直接测量了Nb_3Sn、BSCCO和YBCO超导线材的热应变和晶格应变。在局部应变的基础上，可以研究临界电流与磁场、偏应变、晶界弱连接和微孪晶的应变依赖性和标度律。提出了实用复合超导线材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.