3D optimal design of open type magnetic circuit producing uniform field

摘要

Purpose - The purpose of this paper is to provide an approach to the optimal design of open typernmagnetic circuit of permanent magnet having uniform field.rnDesign/methodology/approach - The Biot-Savart's law and evolution strategy are used for therndesign of permanent magnet configuration. The optimization is carried out by changing the objectivernfunction, dimension of target region, and target flux density.rnFindings - The obtained uniformity is affected by the selection of objective function, dimension ofrntarget region, and target flux density. About 50ppm uniformity of 0.08 T in the imaging area isrnobtained by changing the dimensions, dimension of target region, and target flux of 3D magnets andrnthe amplitudes of magnetization and the directions of magnetization vectors.rnOriginality/value - This paper describes a new approach for obtaining the optimal shape of openrntype magnetic circuit which may be used when magnetic resonance imaging is carried out.