Patent ID: 8849363

Claim:
An open-structure magnetic assembly adapted to generate a homogeneous magnetic field in an accessible space region, comprising a first source of magnetic field and a second independent source of magnetic field, which define a magnet cavity open on at least one side, and each of the first source and the second source generating a contribution to the resulting magnetic field; the first source of magnetic field comprises a conducting or superconducting plate, adapted to propagate a unidirectional current flow from an input side to an output side along a longitudinal direction, and to generate in the spatial volume facing the plate a first substantially unidirectional magnetic field oriented along a direction parallel to the plate and perpendicular to the longitudinal direction of said unidirectional current flow, and a pair of external current recirculating paths between the output side and the input side of said plate, for recirculating the current flowing along the plate, arranged symmetrically with respect to a longitudinal median plane of the plate and each of the current recirculating paths connected between a respective segment of the current output edge and a respective segment of the current input edge of the plate; wherein said current recirculating paths comprise a pair of closing loops for current, formed by a conducting or superconducting web, each of the loops comprising an initial segment and a terminal segment lying in a plane perpendicular to the plane of the plate and parallel to the direction of current flow, and an intermediate segment folded so that the intermediate segment lies in a plane substantially parallel to the plane of the plate; and the second source of magnetic field comprises a volume of magnetized material or an arrangement of coils, arranged for generating a second magnetic field component oriented according to the first magnetic field generated by said first source, and whose intensity exhibits a gradient in a direction perpendicular to the conducting plate adapted to compensate, in a region of interest within the spatial volume region facing the plate and included in the magnet cavity, an opposite gradient in the magnetic field intensity generated by said first source.