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Title: Demagnetization of magnetically shielded rooms

Magnetically shielded rooms for specific high resolution physiological measurements exploiting the magnetic field, e.g., of the brain (dc-magnetoencephalograpy), low-field NMR, or magnetic marker monitoring, need to be reproducibly demagnetized to achieve reliable measurement conditions. We propose a theoretical, experimental, and instrumental base whereupon the parameters which affect the quality of the demagnetization process are described and how they have to be handled. It is demonstrated how conventional demagnetization equipment could be improved to achieve reproducible conditions. The interrelations between the residual field and the variability at the end of the demagnetization process are explained on the basis of the physics of ferromagnetism and our theoretical predictions are evaluated experimentally.
Authors:
; ; ; ;  [1]
  1. Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, FB 8.2 Biosignals, Abbestrasse 2-12, 10587 Berlin (Germany)
Publication Date:
OSTI Identifier:
20953401
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 78; Journal Issue: 3; Other Information: DOI: 10.1063/1.2713433; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; BRAIN; DEMAGNETIZATION; EQUIPMENT; FERROMAGNETISM; MAGNETIC FIELDS; MAGNETIC SHIELDING; MONITORING; NUCLEAR MAGNETIC RESONANCE; RESOLUTION