A new shielding device using U-shaped magnetic material

The authors propose shielding devices constructed with many U-shaped soft magnetic materials. The key feature of these devices is the use of the principle of magnetic shielding based on the vector sum of the external field and the demagnetizing field outside the U-shaped specimen. Shielding effectiveness can be controlled easily by adjusting the demagnetizing factor, which depends on the shape of the specimen. When the demagnetizing field due to the U-shaped specimens cancels the external field perfectly, the shielding factor S (external field/internal field) becomes extremely high (>10³)