Abstract: In order to suppress fringe field due to the magnetic field generated from shield coils along the center axis of main coils and the shield coils that are disposed with their center axes being identical, when reducing fringe field to the outside of a magnet apparatus using the shield coils, the magnet apparatus is configured so that the radii of the main coils are approximately equal to or smaller than the radii of the shield coils, the radii of auxiliary coils are smaller than the radii of the shield coils, the distance between the two main coils is smaller than the distance between the two shield coils, and the distance between the two shield coils is smaller than the distance between the two auxiliary coils.

Abstract: In a magnet system utilizing a pair of magnet bodies each having a cylindrical hollow, by effectively utilizing the hollow spaces of the magnet bodies, the ability of adjusting through magnetic shims the magnetic-field homogeneity of a homogeneous static-magnetic-field space region is enhanced. Two magnet bodies each incorporating a group of superconductive coils and each having a cylindrical hollow are arranged opposing each other; the first ring-shaped magnetic shim is arranged in the cylindrical hollow of the one magnet body, concentrically with the first group of superconductive coils; and the second ring-shaped magnetic shim is arranged inside the first ring-shaped magnetic shim, concentrically with the first group of superconductive coils.

Abstract: In a magnet system utilizing a pair of magnet bodies each having a cylindrical hollow, by effectively utilizing the hollow spaces of the magnet bodies, the ability of adjusting through magnetic shims the magnetic-field homogeneity of a homogeneous static-magnetic-field space region is enhanced. Two magnet bodies each incorporating a group of superconductive coils and each having a cylindrical hollow are arranged opposing each other; the first ring-shaped magnetic shim is arranged in the cylindrical hollow of the one magnet body, concentrically with the first group of superconductive coils; and the second ring-shaped magnetic shim is arranged inside the first ring-shaped magnetic shim, concentrically with the first group of superconductive coils.

Abstract: In order to suppress fringe field due to the magnetic field generated from shield coils along the center axis of main coils and the shield coils that are disposed with their center axes being identical, when reducing fringe field to the outside of a magnet apparatus using the shield coils, the magnet apparatus is configured so that the radii of the main coils are approximately equal to or smaller than the radii of the shield coils, the radii of auxiliary coils are smaller than the radii of the shield coils, the distance between the two main coils is smaller than the distance between the two shield coils, and the distance between the two shield coils is smaller than the distance between the two auxiliary coils.

Abstract: An electromagnetic device has a group of coils which are concentrically wound and used for generating a main magnetic field, and magnetic shims for correcting the uniformity of the main magnetic field in a uniform magnetic field region to be set in the vicinity of the central part of the group of coils. Part of the magnetic shims are arranged in a position where a particular high-order term in the uniform magnetic field becomes substantially zero when the correcting magnetic field generated by that part of the magnetic shims is expressed by a multinomial. The group of coils are arranged in such a manner that part of the high-order terms at the time the main magnetic field is expressed by the multinomial include a high-order magnetic term opposite in polarity to the high-order term of the correcting magnetic field whose order coincides with the order of that part of the high-order terms.

Abstract: To achieve a superconductive magnet apparatus which can suppress the consumption of liquid helium even if a quench phenomenon occurs in the superconductive coil to prevent a reduction in its cooling ability. The superconductive magnet apparatus comprises a superconductive coil 3 which is immersed in liquid helium 2 and stored in the helium container 1, an induction coil 12 which is magnetically coupled to the superconductive coil 3 and thermally insulated from the helium container 1 from each other, and a switching element 14 which forms a closed circuit 13 between both ends of the induction coil 12 when it is made active.