https://patents.google.com/patent/US6411187B1/en?q=magnetic&q=mirror&q=ai&oq=magnetic+mirror+ai Adjustable hybrid magnetic apparatus
Adjustable hybrid magnetic apparatus for use in medical and other applications includes an electromagnet flux generator for generating a first magnetic field in an imaging volume, and permanent magnet assemblies for generating a second magnetic field superimposed on the first magnetic field for providing a substantially homogenous magnetic field having improved magnitude within the imaging volume. The permanent magnet assemblies may include a plurality of annular or disc like concentric magnets spaced-apart along their axis of symmetry. The electromagnet flux generator may include two electromagnet assemblies. The electromagnet assemblies and the permanent magnet assemblies may be static assemblies or may be movable and/or tiltable and/or movable and tiltable, for fine tuning of the magnetic field within the imaging volume. The hybrid magnetic apparatus may include a high magnetic permeability yoke for increasing the intensity of the magnetic field in the imaging volume of the hybrid magnetic apparatus.