REBCO高温超导带材的超导连接技术优化及其对接头超导性能影响机理的研究

REBa2Cu3O7-x(简称REBCO)高温超导带材超导接头是REBCO超导线圈实现闭环续流运行的关键技术。本项目基于前期研究推测REBCO超导性能的各向异性、双轴织构特性、界面区域织构的均匀性是限制REBCO带材超导接头超导性能的关键因素，而接头处低效的氧气扩散通道是引起其渗氧周期较长的主要原因。为获得高性能、短周期及重复性好的REBCO带材超导接头制备技术，本项目拟利用机械法和化学法分离并获得结构完整的缓冲层表面；进一步，构建新的接头结构形式-拼接；最后，在接头连接区域的缓冲层表面，采用PLD法和MOD法制备含有不同掺杂量金属离子的YBCO薄膜介质。本项目将重点研究接头结构形式、生长模板、介质生长方式及掺杂离子对YBCO带材超导接头的制备技术及超导性能的优化机制。此项研究工作将为REBCO带材超导接头技术的实用化提供切实可行的思路和方法，为其在超导NMR、MRI系统中的应用奠定基础。

The superconducting joint of REBa2Cu3O7-x(REBCO) CCS is a key technology for REBCO superconducting coils to realize persistent current operation. Based on previous research, this project speculates that the resistivity anisotropy of REBCO layer, biaxial texture characteristics and texture uniformity in the interface area is the key factors limited the performance of REBCO tape superconducting joints. The inefficient O2 diffusion channel in the joint area is the main reason for the longer oxygen permeation cycle. In order to obtain high-performance, short-period and reproducible superconducting joint technology of REBCO tape, this project intends to use mechanical and chemical methods to separate and obtain a structurally complete buffer layer. Further, a new joint structure named “splicing” will be designed. Finally, the PLD method and the MOD method are used to prepare YBCO thin film containing different amounts of metal ions on the surface of the buffer layer in the joint connection area. This project will focus on the influence mechanism of the joint structure, growth template, medium deposition method, and the doping ions on the preparation technology and superconducting performance of the superconducting joint of REBCO tape. This project is meaningful for superconducting NMR and MRI systems as it puts forward novel ideas and methods for the application of superconducting joint technology of REBCO tape.