Shielded and open superconductive magnet

摘要

An open superconductive magnet (10) useful in magnetic resonance imaging (MRI) applications. The magnet has two spaced apart assemblies (12 and 30), wherein each assembly has a superconductive shielding coil (22 and 40) spaced longitudinally outward and apart from a superconductive main coil (14 and 32). A magnetizable pole piece (24 and 42) is spaced apart from the coils, has a radially-outer portion (26 and 44) at least partially radially overlapping the main coil, and has a longitudinally-inner portion (28 and 46) which projects longitudinally inward past the longitudinally outer end (20 and 38) of the main coil.