Combination of magnets for generating a uniform external magnetic field

摘要

A combination of magnets provides a substantially uniform external magnetic field, in which a plate shaped magnet generates an external magnetic field and a frame shaped magnet generates another external magnetic field. The frame and plate shaped magnets are disposed proximate each other to provide, through the combination of their external magnetic fields, the substantially uniform external magnetic field in a plane disposed substantially parallel to the plate and frame shaped magnets. The size, shape and relative position of the magnets combine to produce an external magnetic field having a highly uniform magnetic field orientation over a wider area of a plane disposed proximate the magnets than heretofore available.