实用化铁基超导线材及其高场内插线圈研究

The iron based superconductor is considered to have a great potential in the field of high magnetic field, due to the advantages of high upper critical field, small anisotropy, simple preparation technology and low material cost. China is in the world leading level in the physical and application research of iron based superconducting materials. High magnetic field magnets, such as nuclear magnetic resonance, fusion reactor and accelerator, are the main applications of iron based superconducting materials, and high field insert coils are the basic research units of high magnetic field magnets. Therefore, it is an important step to carry out the research on high field insert coils. Up to now, the performance of the iron based superconducting wire cannot meet the practical application requirements. The research on the preparation of high performance iron based superconducting wire, and the stress and strain characteristics of the iron based superconducting wire and its related electromagnetic physics, will be carried out. Based on the high performance wire and its characteristic, the high fields insert coil coiling and testing technology will be developed. The above work is expected to obtain high performance iron based superconducting wire and application technology. It is the first work to realize the winding of iron based superconducting coil and 30 T high field testing.

铁基超导体由于具有临界场高、各向异性小、制备工艺简单、成本低廉等优势，被认为在高磁场领域有较大潜在优势，我国在铁基超导材料基础研究和应用研究方面均处于世界领先水平。核磁共振、聚变堆、加速器等高磁场磁体是铁基超导材料的优势应用领域，而高场内插线圈是高磁场磁体的基本研究单元，因而开展高场内插线圈方面的研究是推动铁基超导实用化的重要步骤。项目针对当前铁基超导线材性能不能满足实际应用需求的问题，从限制多晶铁基超导线材临界电流密度提升的微观机制着手，开展高场用高性能铁基超导线材制备研究，同时开展铁基超导线材的应力应变特性及其相关电磁物理特性分析，并在此基础上进行高场内插线圈绕制及测试技术开发，完成铁基超导材料高场应用预演。上述工作的开展，可望获得具有自主知识产权的高场用高性能铁基超导线材及应用技术，率先实现铁基超导内插线圈的绕制和30 T高场测试，进一步巩固我国在铁基超导材料研究领域的优势。

铁基超导体由于具有临界场高、各向异性小、制备工艺简单、成本低廉等优势，被认为在高磁场领域有较大潜在优势，有望应用于核磁共振、聚变堆、加速器等高磁场磁体等领域。项目针对当前铁基超导线材性能不能满足实际应用需求的问题，从限制多晶铁基超导线材临界电流密度提升的微观机制着手，着重分析了致密度和织构度对线材临界电流的影响机理及工艺改进途径，制备了临界电流密度达到1.8×10^5 A/cm^2（4.2 K、10 T）的铁基超导线材短样，继续处于世界领先地位。在此基础上，通过对金属与粉末复合体的塑性变形过程的优化，将百米级铁基超导长线的临界电流密度提高到6×10^4 A/cm^2（4.2 K、10 T），基本满足开展铁基超导装置的验证性实验要求。与此同时，项目基于两家承担单位的工作优势，开展了铁基超导线材的应力应变特性及其相关电磁物理特性分析，成功制备了不同类型的高场内插线圈。在30 T高磁场背景条件下的测试表明，高场内插线圈的临界电流达到67 A（4.2 K、30 T），而且表现了较弱的磁场依赖性，进一步巩固了我国在铁基超导材料研究领域的优势。项目研究过程中发表SCI论文34篇，申请/授权国家发明专利10项。