【摘要】 为了获得高分辨率的稳定清晰图像,用于磁共振成像(MRI)系统的超导磁体应在一定区域内产生高均匀度的磁场,而MgB2/Fe超导带材中的Fe包套材料的磁化作用会影响到空间磁场的分布。因此在设计基于MgB2/Fe复合超导带材的MRI超导磁体时,Fe对磁场分布的影响是需要考虑的关键问题之一。本文使用有限元方法计算MgB2/Fe超导带材的工程磁导率μeng,并在此基础上研究Fe的非线性磁化特性对磁体磁场分布的影响,可为MRI用MgB2/Fe超导磁体的应用提供分析方法上的依据和参考。更多还原

【Abstract】 The superconducting magnet for Magnetic Resonance Imaging (MRI) system must produce a high-homogeneous magnetic field to get high definitional image. But the non-linear magnetization characteristic of Fe affects the magnetic field distribution of MgB2/Fe superconducting magnet. Therefore the effect of Fe-magnetization on magnetic field distribution must be calculated in designing the MgB2/Fe superconducting magnet for MRI. In this work, the MgB2/Fe tape is described as a homogeneous material with the engineering permeability μeng(B) that was calculated from the unit cell model by finite element method (FEM), based on that the effect of Fe-magnetization on magnetic field distribution is analyzed in detail. The results can give some useful reference in the design of MgB2/Fe superconducting magnet for MRI.更多还原