Patent ID: 7271689

Claim:
A magnet structure, comprising: a frame supporting first and second opposing permanent magnet assemblies; wherein the frame includes a base, first and second extensions connected to the base and to the respective first and second opposing permanent magnet assemblies, and first and second support structures supporting the respective first and second opposing permanent magnet assemblies with respect to the base; and wherein the first and second opposing permanent magnet assemblies each include an enclosure having an open end, a pole, disposed on the enclosure, having a pole face, and arranged such that the pole face opposes the pole face of the other permanent magnet assembly, a magnetic mass disposed within the enclosure, and a cover over the open end of the enclosure; wherein the magnetic mass is a plurality of discrete magnetic elements made from a first magnetic material; wherein the discrete magnetic elements are bricks made from a first magnetic material; wherein the bricks are stacked so as to substantially conform to the shape of the enclosure and filling the enclosure; and further comprising a brace connected between the cover and a first side of the enclosure on which the pole is disposed.