TY - JOUR
T1 - Fundamental Characteristics of a Large-Scale Cylindrical Magnetic Shield with Shaking
AU - Sasada, I.
AU - Ohnaka, Y.
PY - 1994
Y1 - 1994
N2 - A large-scale cylindrical magnetic shielding case was developed. It was made of permalloy (outer diameter 68 cm, length 180 cm, thickness 1.6 mm, weight approximately 60 kg) with an opening at one end and with Metglas® 2705M amorphous ribbons (width 5 cm, thickness approximately 22 µm) wound spirally about the permalloy case in 16 layers (total weight 12.1 kg) to cover the surface. A toroidal coil (36 turns) was wound around the amorphous layers to allow the creation of a magnetic shaking field. An external magnetic field was applied to the shielding case by means of a large rectangular Hemholtz coil, to evaluate the shielding factor, which was about 2700 at a frequency of 0.5 Hz when the shaking frequency was 200 Hz. At higher frequencies, it gradually dropped. The shielding factor was almost constant relative to the amplitude of the disturbing field down to 3 mG; beyond that point, a residual field could not be detected because of the limit of resolution of the flux gate magnetometer used. The leakage of the shaking field was about 30 µG at the center of the shielding case.
AB - A large-scale cylindrical magnetic shielding case was developed. It was made of permalloy (outer diameter 68 cm, length 180 cm, thickness 1.6 mm, weight approximately 60 kg) with an opening at one end and with Metglas® 2705M amorphous ribbons (width 5 cm, thickness approximately 22 µm) wound spirally about the permalloy case in 16 layers (total weight 12.1 kg) to cover the surface. A toroidal coil (36 turns) was wound around the amorphous layers to allow the creation of a magnetic shaking field. An external magnetic field was applied to the shielding case by means of a large rectangular Hemholtz coil, to evaluate the shielding factor, which was about 2700 at a frequency of 0.5 Hz when the shaking frequency was 200 Hz. At higher frequencies, it gradually dropped. The shielding factor was almost constant relative to the amplitude of the disturbing field down to 3 mG; beyond that point, a residual field could not be detected because of the limit of resolution of the flux gate magnetometer used. The leakage of the shaking field was about 30 µG at the center of the shielding case.
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U2 - 10.1109/TJMJ.1994.4565954
DO - 10.1109/TJMJ.1994.4565954
M3 - Article
AN - SCOPUS:84923469595
SN - 0882-4959
VL - 9
SP - 33
EP - 38
JO - IEEE Translation Journal on Magnetics in Japan
JF - IEEE Translation Journal on Magnetics in Japan
IS - 6
ER -