Patent ID: 11199599

Abstract:
A magnet assembly in a magnetic resonance apparatus includes a cryostat and a superconducting main field magnet coil system arranged therein for generating a magnetic field in the direction of a z-axis in a working volume. The magnet assembly includes a shim device arranged inside the cryostat for adjusting the spatial variation or homogeneity of the magnetic field generated in the working volume by the magnet coil system. The shim device comprises at least one closed superconducting shim conductor path having an HTS layer. The HTS layer forms a surface that is geometrically developable such that unwrapping onto a plane changes the geodesic distance between any two points on the surface formed by the HTS layer by no more than 10%. The inner and/or outer contour of the geometrical development of the HTS layer describes a non-convex curve.