PURPOSE: To make it possible to obtain a desired magnetic field having excellent accuracy and intensity in a cavity, by forming the cavity in a substrate made of a magnetic material, inserting a core made of a magnetic material having a shape that fits in said cavity, forming a unitary body, magnetizing the body, and thereafter removing the core out of the substrate.
CONSTITUTION: At first, a cylindrical core 1 is manufactured with a magnetic material. As the magnetic material, 'Alnico(R)' based material, samarium cobalt based material and rare earth boron based material can be listed. Then, a rectangular parallelopiped substrate 2 is manufactured with the same magnetic material as that of the cylindrical core 1. A cylindrical cavity 3 having a shape that fits in the cylindrical core 1 is formed. Then, the cylindrical core 1 is inserted into the cylindrical cavity 3 in the rectangular parallelopiped substrate 2 so as to form a unitary body. The substrate is magnetized. At this time, since the cylindrical cavity 3 of the rectangular parallelopiped substrate 2 is filled with the cylindrical core 1, the inside is uniformly magnetized. After the magnetization, a magnet 10 having the cavity 3 is obtained. Magnetic dipoles appear in the density distribution of cos θ on the inner wall. An extremely uniform, intense magnetic field is formed in the cavity 3.
NISHIMOTO YOSHIO
YASUKUNI HIROAKI
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