Analysis of the magnetic property of a permanent-magnet-type MRI-behavior of residual magnetization

Author

Takahashi, Norio ; Suenaga, Ryousuke ; Miyata, Koji ; Ohashi, Ken

Author_Institution

Dept. of Electr. & Electron. Eng., Okayama Univ., Okayma, Japan

Volume

39

Issue

3

fYear

2003

fDate

5/1/2003 12:00:00 AM

Firstpage

1337

Lastpage

1340

Abstract

The minor loops of B and H of steel due to pulse excitation and eddy currents induced in steel affect the magnetic characteristics of a permanent-magnet-type MRI. In this paper, the magnetic properties of a permanent magnet assembly is examined by using the finite-element method taking into account minor loop. The distribution of residual magnetization in the yoke is illustrated, and the effect of residual magnetization on the behavior of residual flux density is examined. It is shown that the behavior of B and H in minor loops is affected by the eddy currents in the yoke and pole piece.

Keywords

biomedical MRI; eddy currents; finite element analysis; magnetic hysteresis; magnetisation; permanent magnets; steel; FEM; eddy currents; finite-element method; magnetic characteristics; minor loops; permanent magnet assembly; permanent-magnet-type MRI; pole piece; pulse excitation; residual flux density; residual magnetization distribution; steel; yoke; Assembly; Eddy currents; Finite element methods; Magnetic analysis; Magnetic flux; Magnetic properties; Magnetic resonance imaging; Magnetization; Permanent magnets; Steel;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2003.810510

Filename

1198468