| 摘要 |
PROBLEM TO BE SOLVED: To provide a lightweight open type superconductive magnet having a high magnetic field intensity and capable of providing a stable magnetic field uniformity. SOLUTION: In this open type magnet 10, a disc-like ferromagnetic body group is arranged between each of superconductive main coils 12 arranged opposite to each other with a uniform magnetic field data 11 between and each of superconductive shield coils 13 arranged on the outside of the superconductive main coils 12. The ferromagnetic body group is formed of a first ferromagnetic body 18 consisting of a structural member to support the superconductive main coil 12 and other ferromagnetic bodies, arranged on the outside of the superconductive main coils 12, a second ferromagnetic body 22 arranged on the outside of the first ferromagnetic body 18 and having a high saturated magnetic flux density, a third ferromagnetic body 24 arranged near the bore side of the superconductive main coil 12 and having a high saturated magnetic flux density. The outer diameter of the superconductive shield coil 13 is larger than the diameter of the superconductive main coil 12, and the maximum diameter of the ferromagnetic body group is middle between both the coil outer diameters. The first ferromagnetic body 18 and the second and third ferromagnetic bodies 22 and 24 improve the magnetic field uniformity to suppress the leak magnetic field. |
