使用改进的形状优化方法设计高均匀度的超导MRI磁体

摘要

针对设计带铁磁的超导磁共振成像磁体,提出了一种确定类的优化算法来优化极靴的形状以达到匀场的目的.这种方法集合了灵敏度分析、形状优化的理论和有限元方法计算非线性铁磁材料极靴的配置,来改善两个极靴之间大体积成像区的磁场均匀度.需要指出的是,本优化方法不受极靴初始形状的限制,均可以快速收敛.我们通过一个紧凑型的1.2T双平面磁共振磁体,展示了这种方法.%We presented a non - stochastic optimization method for optimizing the shapes of ferromagnetic materials to generate a target static magnetic field for an open superconducting MRI magnet. The method integrated sensitivity analysis and shape optimization with the finite element method (FEM) to calculate nonlinear ferromagnetic material configurations, devoting to improve the homogeneity of the magnetic field in a large imaging volume between the poles. It should be noted that the initial condition of the material shape was not critical for convergence. We demonstrate this method works well with a compact 1. 2T yoked bi - planar MRI magnet.