A permanent magnet for NMR

Author

Battocletti, Joseph H. ; Myers, Thomas J.

Author_Institution

Milwaukee VA Med. Center, WI, USA

Volume

25

Issue

5

fYear

1989

fDate

9/1/1989 12:00:00 AM

Firstpage

3910

Lastpage

3912

Abstract

A 0.105-T (1050-G) whole-body permanent-magnet structure has been designed by 3-D and 2-D, finite-element analysis, constructed using simple manufacturing techniques, and passively shimmed to yield a homogeneity factor of 105 p.p.m. over a 25-cm- (10-in) diameter sphere. Ceramic type 10 magnetic material is used. An expert computer program that utilizes all the shimming data for additional homogeneity improvement has been written. The program, which includes over 1000 inhomogeneity conditions, could be used for shimming other magnet structures. Transient temperature tests show that the magnetic flux density at the center of the working air gap can change significantly in the short term, so that temperature stability of the magnet environment is required

Keywords

CAD; biomedical NMR; electrical engineering computing; expert systems; finite element analysis; permanent magnets; 0.105 T; NMR; ceramic type 10 material; expert computer program; finite-element analysis; inhomogeneity conditions; magnetic flux density; magnetic material; passive mechanical shimming; permanent magnet; shimming data; temperature stability; transient temperature tests; whole-body imaging; working air gap; Ceramics; Finite element methods; Magnetic analysis; Magnetic flux; Magnetic materials; Manufacturing; Nuclear magnetic resonance; Permanent magnets; Temperature; Testing;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.42474

Filename

42474