An elliptical cylinder-type shielding device using amorphous ribbons

A novel elliptical-cylinder-type shielding device for static magnetic fields is presented. This device consists of two domes using 25- mu m thick METGLAS 2826-MB amorphous ribbons. Amorphous ribbons were attached to the legs of the domes in a U-shaped configuration. The U-shaped amorphous ribbons are magnetized by an external field, and a demagnetizing field was set up to cancel the external field. Shielding effectiveness can be controlled easily by adjusting the length of the U-shaped amorphous ribbons and the distance between the apexes of the domes. A shielding factor defined as external field intensity/internal field intensity becomes higher than 10/sup 3/ when the demagnetizing field of the U-shaped amorphous ribbon completely cancels the external field.<
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