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Superconducting magnetic shield for MEG coupled with permalloy PC
Author(s) -
Irisawa Daiichi,
Imai Kumiko,
Shintomi Koichi,
Yahara Akihito,
Matsubara Hironori
Publication year - 2019
Publication title -
electrical engineering in japan
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.136
H-Index - 28
eISSN - 1520-6416
pISSN - 0424-7760
DOI - 10.1002/eej.23195
Subject(s) - permalloy , electromagnetic shielding , superconductivity , magnetometer , magnetic field , cylinder , shield , magnetic noise , field (mathematics) , physics , noise (video) , biomagnetism , electrical engineering , materials science , nuclear magnetic resonance , condensed matter physics , engineering , mechanical engineering , magnetization , mathematics , computer science , petrology , quantum mechanics , geology , artificial intelligence , pure mathematics , image (mathematics)
Abstract The Biomagnetism measurement is required shielding effect 1/ S ≦1/10 −7 for using SQUID magnetometer. The superconducting shield is possible to realize ideal low magnetic noise space. But it is required to attenuate every external field inside the superconducting hollow cylinder equally. Especially, radial external field decreases gently comparison to axial field. At this time the length of cylinder needs 4.4 m for diameter 1 m to realize shielding effect 1/ S ≦1/10 −7 . On the other hand, it is only 2.1 m for axial field. For that reason, we devised two methods to attenuate radial field rapidly coupled with permalloy.