Electromagnetic Design of 1.0-T Ultrashort-Cavity Intraoperative Head MRI Superconducting Magnet

This article provides an overview of the design and verification of a 1.0-T ultrashort-cavity intraoperative head magnetic resonance imaging (MRI) superconducting magnet. We proposed a linear programming method with repeated iterations for the electromagnetic design of superconducting magnets in MRI, referred to as repeated iterative linear programming (RILP). By employing RILP, we first investigated the influence of axial length on the maximum magnetic induction intensity, the number of coils, and the cost of superconducting material. The rectangularization of current clusters during the linear programming phase of the electromagnetic design was then completed. The electromagnetic force, stress, and strain were also analyzed. Finally, passive shimming within linear programming was performed on the superconducting magnet, resulting in magnetic field inhomogeneity within 20-cm diameter of spherical volume being below 8 ppm. The designed superconducting magnet meets the technical requirements for intraoperative head MRI, with a total length of 960 mm and a bore size of 650 mm.