Maximum likelihood estimation of all strand positions in Cable-in-Conduit superconductor considering compressed deformation

由管道中的电缆导体制成的大型超导线圈在强磁场下运行时，其超导特性会恶化。这是因为每一股都偏离了预期的初始位置，并与外部磁场不规则地联系在一起。为了探讨产生这种现象的原因，分别采用等面积法和全股机械应变能极小化方法，在考虑了空隙率、扭距和压缩变形等导体参数的情况下，对导线中的三维全股位置进行了分析，并与实测值进行了比较。由于分析结果表明，许多统计量与实测值吻合较好，这一分析明确了劣化的原因。

Large scale superconducting coil made of cable-in-conduit conductor causes deterioration on superconductivity characteristics when it is operated under high magnetic field. This stems from that each strand deviates from the expected original position and irregularly links with external magnetic field. In order to investigate the cause, three dimensional all strand locations in the conductor are analyzed by both equal area method and minimization method of mechanical strain energies of all strands with consideration of conductor parameters such as void fraction and twist pitches and compressed deformation, and then are compared with measured ones. Since the results show many analyzed statistical quantities are in good agreement with measured ones, this analysis makes clear the cause of deterioration.