| 摘要 |
A magnetic construction having a rectangular cross section cavity (20) with a uniform magnetic field therein, comprising an element of high-permeability material (30) having a flat surface and positioned to define one wall of said cavity (20), and a magnetic structure (10-14) at least partly of permanent magnetic material defining three further walls of said cavity (20), said magnetic structure (10-14) having a surface spaced from said flat surface of said element of high permeability material (30), said flat surface and the surface of said structure of magnetic material (10) defining opposed walls of said cavity (20), wherein the magnetic construction further comprises a partial yoke (65) on said magnetic structure (10-14) and spaced from said flat surface, and a magnetic shunt (80) of a magnetic material of remanence lower than that of said magnetic structure (10-14) extending between said yoke (65) and said flat surface. <IMAGE> |
