DocumentCode :
1450976
Title :
Effective combination of magnetic and conductive layers of magnetically shielded room [for biomagnetic measurements]
Author :
Yamazaki, Keita ; Kato, Kazuo ; Fujiwara, Koji
Author_Institution :
Res. & Dev. Inst., Takenaka Corp., Chiba, Japan
Volume :
36
Issue :
5
fYear :
2000
fDate :
9/1/2000 12:00:00 AM
Firstpage :
3649
Lastpage :
3651
Abstract :
This paper describes the optimal design of magnetically shielded room used for measurements of extremely weak magnetic fields such as biomagnetic measurements, in which the higher shielding factor is required in the frequency range from 0.01 Hz to several ten Hz at a low cost. The 3D magnetic field analysis is carried out by using the finite element method taking account of eddy currents to estimate an effective combination of magnetic and conductive layers for the design of wall and door. It is confirmed that as regards the wall design, an Al layer itself can increase the shielding effect by a sandwiched PC-Al-PC (PC: permalloy, Al: aluminum) combination even at frequencies at which only Al layer has no shielding effect. When the wall is composed of four layers [PC(inner)-PC(middle)-Al-PC(outer)], the door composed by the Al and outer PC layers is supposed to be optimal from the standpoints of shielding effect and cost. Its shielding fatter is comparable to that of the door composed of Al, inner and middle PCs
Keywords :
biomedical equipment; biomedical measurement; eddy currents; finite element analysis; magnetic field measurement; magnetic noise; magnetic shielding; magnetocardiography; magnetoencephalography; 3D magnetic field analysis; Al; MCG; MEG; NiFe-Al; Permalloy-Al sandwich; biomagnetic measurements; conductive layers; eddy currents; effective combination of layers; extremely weak magnetic field measurements; finite element method; high shielding factor; low cost; magnetic layers; magnetic noise; magnetically shielded room; optimal design; wall design; Aluminum; Biomagnetics; Cost function; Eddy currents; Finite element methods; Frequency measurement; Magnetic analysis; Magnetic field measurement; Magnetic shielding; Personal communication networks;
fLanguage :
English
Journal_Title :
Magnetics, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9464
Type :
jour
DOI :
10.1109/20.908929
Filename :
908929
Link To Document :
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