Simulation and optimisation of homogeneous permanent magnet for portable NMR applications


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International Journal on Smart Sensing and Intelligent Systems

Professor Subhas Chandra Mukhopadhyay

Exeley Inc. (New York)

Subject: Computational Science & Engineering, Engineering, Electrical & Electronic


eISSN: 1178-5608



VOLUME 7 , ISSUE 5 (December 2014) > List of articles

Special issue ICST 2014

Simulation and optimisation of homogeneous permanent magnet for portable NMR applications

Patrick Poulichet / Abdennasser Fakri / Christophe Delabie / Hung Dang Phuc / Tien Truong Cong / Latifa Fakri-Bouchet

Keywords : component; Nuclear Magnetic Resonance; Low field; portable permanent Magnet; Halbach; Shim magnets; Homogeneity simulation

Citation Information : International Journal on Smart Sensing and Intelligent Systems. Volume 7, Issue 5, Pages 1-6, DOI:

License : (CC BY-NC-ND 4.0)

Published Online: 15-February-2020



This paper focuses on the magneto static simulation of magnet arrangement used for portable NMR (Nuclear Magnetic Resonance) apparatus. In NMR experiments, a very homogeneous magnetic field is required in a large sample volume. In our case, NdFeB magnets are used to generate a homogeneous field, with a Halbach arrangement. The homogeneity of the magnetic field B0 can be improved by dividing a long configuration of magnets into several rings. The size of useful volume is dependent on both the gap between each ring and some others shim magnets. Our aim is to enhance the sensitive volume size while maintain the highest magnetic field. In this goal, we optimized the gap between the two rings and put two shim magnets rings in the bore of the structure. Optimizing the position of the shim magnets allow drastic improvement. The homogeneity of the magnetic field B0 is optimized with the help of CAD and mathematical software. Our results were confirmed with a Finite Element Method. As a result the method described here achieves a significant improvement of the homogeneity in the particular case of Halbach arrangement.

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[1] Carel W. Windt, Helmut Soltner, Dagmar van Dusschoten, Peter Blümler,” A portable Halbach magnet that can be opened and closed without force: The NMR-CUFF” Journal of Magnetic Resonance 208 (2011) 27–33.

[2] S. Anferova, V. Anferov, J. Arnold, E. Talnishnikh, M. A. Voda, K. Kupferschläger, P. Blümler, Ch. Clauser, B. Blümich. Improved Halbach sensor for NMR scanning of drill cores Magnetic Resonance Imaging 25, 2007, pp 474-480.

[3] K. Halbach,” Design of Permanent Multipole Magnets with Oriented Rare Earth Cobalt Materials”,Nucl. Instr. Meth., 169: (1980),1-10.

[4] Raich and P. Blümler “Design and Construction of a Dipolar Halbach Array with an Homogeneous Field from Identical Bar-Magnets – NMR Mandhalas-“, Concepts in Magnetic Resonance. B: Magnetic Resonance Engineering. 23B(1), 2004, pp16-25.

[5] H. Soltner, P. Blumler, ”Dipolar Halbach Magnet Stacks Made from Identically Shaped Permanent Magnets for Magnetic Resonance”, Concepts in Magnetic Resonance part A, (2010), Vol. 36A(4) 211–222.

[6] B P Hills, K M Wright, and D G Gillies. A lowfield, low-cost Halbach magnet array for openaccess NMR.Journal of magnetic resonance (San Diego, Calif.: 1997), 2005,175(2):336–9.

[7] E. Danieli, J. Mauler, J. Perlo, B. Blümich, F. Casanova, Mobile sensor for high resolution NMR spectroscopy and imaging, Journal of Magnetic Resonance. 198, 2009, pp 80 -87.

[8] C. Hugon, F. D’Amico, G. Aubert, D. Sakellariou, “Design of arbitrarily homogeneous permanent magnet systems for NMR and MRI: Theory and experimental developments of a simple portable magnet“, Journal of Magnetic Resonance 205, 2010, pp75-85.

[9] R.C .Jachmann, D.Sakellariou, R.W.Matin, R.D.Schlueter, T.F.Budinger, A.Pines. Multipole shimming of permanent magnets using harmonic corrector rings. Review of Scientific Instruments 78(2007), 035115.

[10] http://www. are/Radia/Documentation/Introduction