Design of Superconducting Magnet for 1.5 T Dedicated Extremity MRI System

In this paper, an effective method to design the superconducting magnet for 1.5 T dedicated extremity MRI is proposed. The feasible current carrying zones of superconducting magnet are subdivided by an array of grid elements. The size of each grid element is determined by the actual superconducting wire. The initial current distribution of superconducting magnet is optimized using 0-1 integer programming by a comprehensive consideration of superconductivity wire consumption, central magnetic field intensity, imaging region homogeneity, and the range of leakage file. The final rectangular section of magnet is obtained using the genetic algorithm optimization with artificial limitation of the coil position and section size considering the initial current distribution of superconducting magnet. The method based on the actual superconducting wire makes the MRI magnet design more feasible. A superconducting magnet for 1.5 T dedicated extremity MRI system is designed using this method. This magnet can offer 1.5 T central field with high homogeneity in diameter sphere volume (DSV), with total length of 430 mm, inner diameter of 350 mm. This method can also be used for short whole-body MRI superconducting magnet design.