| 摘要 |
A C-shaped superconducting magnet for use in magnetic resonance imaging (MRI) equipment is disclosed. The magnet includes flux concentrators on opposing sides of the gap, for generating a vertical field therein; the flux concentrators include a plurality of coils, for carrying current in opposing directions, so as to generate an inwardly directed field to compensate for the gap. Injection correctors, each consisting of a horizontal coil, are disposed adjacent the flux concentrators. A flux return body, for example a superconducting solenoid or an iron yoke, provides a return path on the opposite side of the magnet from the gap. Flux deflectors guide return flux in a curved path from the flux return body to the injection correctors. The flux deflectors are constructed to include a superconducting coil which is wound about varying chords (or the full diameter) thereof, so that the induced flux is greater nearer the outside of the flux deflector, compensating for the tendency of the flux to crowd along the inner portion of the curved path. The return flux is thus provided to the injection correctors with sufficient uniformity to be corrected thereby.
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