Rotatable small permanent magnet array for ultra-low field nuclear magnetic resonance instrumentation: a concept study

Vogel, Michael W., Giorni, Andrea, Vegh, Viktor, Pellicer-Guridi, Ruben and Reutens, David C. (2016) Rotatable small permanent magnet array for ultra-low field nuclear magnetic resonance instrumentation: a concept study. PLoS One, 11 6: . doi:10.1371/journal.pone.0157040


Author Vogel, Michael W.
Giorni, Andrea
Vegh, Viktor
Pellicer-Guridi, Ruben
Reutens, David C.
Title Rotatable small permanent magnet array for ultra-low field nuclear magnetic resonance instrumentation: a concept study
Journal name PLoS One   Check publisher's open access policy
ISSN 1932-6203
Publication date 2016-06-06
Sub-type Article (original research)
DOI 10.1371/journal.pone.0157040
Open Access Status DOI
Volume 11
Issue 6
Total pages 24
Place of publication San Francisco, United States
Publisher Public Library of Science
Language eng
Formatted abstract
Object

We studied the feasibility of generating the variable magnetic fields required for ultra-low field nuclear magnetic resonance relaxometry with dynamically adjustable permanent magnets. Our motivation was to substitute traditional electromagnets by distributed permanent magnets, increasing system portability.

Materials and Methods


The finite element method (COMSOL®) was employed for the numerical study of a small permanent magnet array to calculate achievable magnetic field strength, homogeneity, switching time and magnetic forces. A manually operated prototype was simulated and constructed to validate the numerical approach and to verify the generated magnetic field.

Results

A concentric small permanent magnet array can be used to generate strong sample pre-polarisation and variable measurement fields for ultra-low field relaxometry via simple prescribed magnet rotations. Using the array, it is possible to achieve a pre-polarisation field strength above 100 mT and variable measurement fields ranging from 20–50 μT with 200 ppm absolute field homogeneity within a field-of-view of 5 x 5 x 5 cubic centimetres.

Conclusions

A dynamic small permanent magnet array can generate multiple highly homogeneous magnetic fields required in ultra-low field nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) instruments. This design can significantly reduce the volume and energy requirements of traditional systems based on electromagnets, improving portability considerably.
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: HERDC Pre-Audit
Centre for Advanced Imaging Publications
 
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Created: Wed, 08 Jun 2016, 02:01:04 EST by Dr Viktor Vegh on behalf of Centre for Advanced Imaging