【摘要】 在磁体外部构建片状均匀磁场区域,是磁体设计所面临的一个全新问题。文中提出了一种混合逆数值算法,以探索这种设计的可行性。混合逆数值算法是一种两步算法,包含直接矩阵反演求逆和二次规划两个步骤。文中对该数值算法进行了详细的描述,并用它成功地找到一种多磁块组合的单边永磁磁体结构。经通用有限元计算软件仿真和对磁体模型的测量表明,这种磁体结构能够较好地在磁体外部一侧构建片状均匀磁场区。用单边永磁磁体在磁体外部构建片状均匀磁场区的实现,为开展单边均匀场常规磁共振成像系统研制等科学研究打下了坚实的基础。更多还原

【Abstract】 It is a totally new problem about magnet design to build a slice with homogeneous magnetic field outside of the used magnet. A so-called Hybrid Inverse numerical method is proposed here to probe the existence possibility of such a magnet design. The Hybrid Inverse numerical method is a two-step numerical method, comprising of direct matrix inversion and quadratic programming. The numerical method is described in detail at first and then is used to find a unilateral permanent magnet structure made from some small magnetic blocks. Electromagnetic simulations with a widely used FEM software and measurement of a magnet model with such a structure show that a slice with homogeneous magnetic field outside of the used magnet can be obtained with the magnet structure. The success of such a unilateral permanent magnet builds a strong basis for some scientific research such as the construction of a unilateral MRI system with homogeneous magnetic field.更多还原