High-performance magnetically shielded room

Author

Kajiwara, G. ; Harakawa, K. ; Ogata, H. ; Kado, H.

Author_Institution

Superconducting Sensor Lab., Chiba, Japan

Volume

32

Issue

4

fYear

1996

fDate

7/1/1996 12:00:00 AM

Firstpage

2582

Lastpage

2585

Abstract

An ultrahigh-performance magnetically shielded room was completed as a part of a biomagnetic measuring system using superconducting quantum interference device. From the difference between environmental magnetic noise and a signal, necessary shielding factor was decided to be 1/100000 at low frequencies and 1/1000 at high frequencies. The soccer ball shaped room consists of four layers of permalloy and a layer of aluminum, and provides a space 4 meters in diameter in which magnetic fields are very weak. An independent base was built and the room was fixed rigidly to it. Because permalloy is very sensitive to shocks, the materials for the room were cut in the factory, carried with care, and assembled with screws on site. Xenon lamps supply light via optical fibers and the room is ventilated by way of many small holes in the floor. The door is equipped with the air pressure system

Keywords

biomagnetism; biomedical engineering; biomedical measurement; laboratories; magnetic noise; magnetic shielding; Al; FeNi; SQUID; Xenon lamps; air pressure system; aluminum layer; biomagnetic measuring system; magnetic noise; magnetically shielded room; optical fibers; permalloy layer; ventilation; weak magnetic fields; Biomagnetics; Frequency; Interference; Magnetic devices; Magnetic shielding; SQUIDs; Superconducting device noise; Superconducting devices; Superconducting epitaxial layers; Superconducting magnets;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.511401

Filename

511401