Many factors affect the magnetic field quality of superconducting magnet, among which the persistent current originating from the inherent attribute of superconducting material exists for a long time and has a greater influence on the magnetic field quality, and its influence on the magnetic field of highly homogeneous magnets has not been reported yet. Based on the critical state model, the magnetization curve of a single superconducting wire, as well as the variation of the higher-order magnetic field components with current of a typical pre-cycle are simulated for a 7 T highly homogeneous magnet. For the validation, the magnetization curves of a single superconducting wire are measured, and the superconducting magnet is subjected to a cool-down test. Compared to zonal harmonics, more obvious hysteresis phenomena for tesseral harmonic components are observed and validated, which confirmed the effectiveness of this methodology.

影响超导磁体磁场质量的因素很多，其中源于超导材料固有属性的持续电流存在时间长，对磁场质量影​​响较大，对高度均匀磁场的影响较大。磁铁尚未报道。基于临界状态模型，模拟了7T高均质磁体单根超导线的磁化曲线，以及典型预循环高阶磁场分量随电流的变化。为了验证，测量单根超导线材的磁化曲线，并对超导磁体进行冷却测试。与区域谐波相比，