Magnetic enclosure and method

摘要

A magnetic enclosure providing a uniform magnetic field in a test chamber and comprising substantially identical first north magnetic structure and second south magnetic structures that are disposed in geometric mirroring symmetry opposite to each other and separated by an air gap forming the test chamber. Each magnetic structure includes a cap-like permanent magnet assembly covering a convex ferromagnetic pole piece, a ferromagnetic cap-like shield covering the magnet assembly, and a ferromagnetic ring. The ring is in contact with and intermediate the shield of the first and of the second magnetic structure, and has at least one aperture allowing access to the test chamber.

主权项

1. A magnetic enclosure providing a homogeneous, stable, and uniform magnetic field in a test chamber, the magnetic enclosure comprising:
a north portion substantially identical to a south portion disposed in geometric mirroring symmetry opposite to each other and mutually separated apart by an air gap, each one of the north portion and the south portion comprising:
a permanent magnet shell magnetized in a radial-like orientation and shaped to approximate a hemisphere, the permanent magnet shell having a convex magnet exterior surface and a concave magnet interior surface;a ferromagnetic pole piece having a pole piece convex surface disposed in abutting contact with the concave magnet interior surface, and having a pole piece base surface; anda ferromagnetic shield having a shield rim from which extend a convex shield exterior surface and a concave shield interior surface that is disposed in abutting contact with the convex magnet exterior surface; and a ferromagnetic ring disposed in abutting contact with and intermediate between the shield rim of the north portion and the shield rim of the south portion to bridge the air gap and to form the test chamber to which access is provided via at least one aperture opened in the ring.