Variable strength beam line multipole permanent magnets and methods for their use
Method of NMR imaging which overcomes T2 * effects in an inhomogeneous static magnetic field
NMR Imaging apparatus Patent #: 4498048
AbstractA permanent magnet assembly for use in magnetic resonance imagers requires a minimum of permanent magnet material. The magnets are arranged with a radial direction of magnetization and an iron return path is used. The specific configurations of the permanent magnets provide highly uniform magnetic fields in the bore of the assembly.