Design, fabrication and evaluation of a low-cost homogeneous portable permanent magnet for NMR and MRI

Hugon, Cédric; Aguiar, Pedro M.; Aubert, G.; Sakellariou, Dimitrios

doi:10.1016/j.crci.2009.09.009

Cited by 25 publications

(25 citation statements)

References 14 publications

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“…This method provided expressions of the coefficients of the development to arbitrary order and the means for numerical optimization for field homogeneity. A more detailed description of the theoretical framework was recently reported by Hugon et al [16,17] Halbach's and Aubert's developments lead to structures that produce transverse and vertical magnetic fields, respectively, as shown in Fig. 1.…”

Section: Theorymentioning

confidence: 92%

“…The number of segments will determine the number of non-zero skewed terms in the spherical harmonics developments of the magnetic potential that will be null by construction. Usually, n segments impose n skewed terms to be equal to zero for the longitudinal configuration, [16] and n−2 terms for the Halbach configuration. [17] In this case, the interleaved structure of the magnet reduces the symmetry of the magnetic field and only half of the skewed terms will be canceled by construction.…”

Section: Theorymentioning

confidence: 99%

“…Here we have applied an analytical theory of 3 D magnetostatics, [16,17] to devise a cylindrical magnet assembly that produces an arbitrarily homogeneous and inclined strong magnetic field. We have built a low cost prototype and performed Hall probe and NMR measurements to evaluate its performance and compare it with the theoretical predictions.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Permanent magnet assembly producing a strong tilted homogeneous magnetic field: towards magic angle field spinning NMR and MRI

Sakellariou

Hugon

Guiga

et al. 2010

Magnetic Reson in Chemistry

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We introduce a cylindrical permanent magnet design that generates a homogeneous and strong magnetic field having an arbitrary inclination with respect to the axis of the cylinder. The analytical theory of 3 D magnetostatics has been applied to this problem, and a hybrid magnet structure has been designed. This structure contains two magnets producing a longitudinal and transverse component for the magnetic field, whose amplitudes and homogeneities can be fully controlled by design. A simple prototype has been constructed using inexpensive small cube magnets, and its magnetic field has been mapped using Hall and NMR probe sensors. This magnet can, in principle, be used for magic angle field spinning NMR and MRI experiments allowing for metabolic chemical shift profiling in small living animals.

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Section: Theorymentioning

confidence: 92%

Section: Theorymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Permanent magnet assembly producing a strong tilted homogeneous magnetic field: towards magic angle field spinning NMR and MRI

Sakellariou

Hugon

Guiga

et al. 2010

Magnetic Reson in Chemistry

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“…The design was deduced from the work of Hugon (Hugon et al 2010a, b) on a patent of Aubert. Hugon investigated an arrangement, which allowed the generation Separation efficiency [-] of a field rotationally symmetric to an axis and longitudinal in axis direction.…”

Section: Setupmentioning

confidence: 99%

Magnetically Enhanced Centrifugation for Industrial Use

Lindner

Keller

Grim

et al. 2014

Upscaling of Bio-Nano-Processes

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Magnetically enhanced centrifugation is a new approach in high-gradient magnetic separation possible in continuous mode, which promises a large potential for industrial use. Magnetic particles are separated to a wire filter, from which they are cleaned by centrifugal forces to the chamber wall. The simulation of magnetic particles collected by a wire were possible by the discrete element method. The simulation shows the detachment of particles from the wires by the centrifugal force. Two prototype machines were set up to investigate the process. The discharge of particles from the wire filter depends on the magnetic field strength and the centrifugal velocity. It was possible to set up a machine reaching a separation efficiency of 99 % at a volume flow of 1 m 3 /h (excluding dead times) in a batch-wise mode. A second machine built as magnetically enhanced decanter separates particles and transports them out of the bowl by a screw conveyor in a completely continuous mode. Instead of the common electromagnets a permanent magnet assembly can be combined with a magnetically enhanced centrifuge to save costs.

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“…The cylindrical structure and later the spherical structure [5] allowed dipolar magnetic fields exceeding 2 T to be produced. Since then, several research groups and companies have refined Halbach's structures and together with shim coils magnets up to around 1.5 T can be obtained with homogeneity to better than 0.05 ppm, allowing for the resolution of chemical shifts and nuclear spinspin couplings in the measured NMR spectra [6][7][8][9][10][11][12][13][14]. The sensitivity at 1.5 T is around 10 À7 1 H moles, sufficing for most analyses of solution-state samples in the synthetic chemistry laboratory and at a price point that can enter the teaching laboratory.…”

Section: Introductionmentioning

confidence: 99%

Low-cost, pseudo-Halbach dipole magnets for NMR

Tayler

Sakellariou

2017

Journal of Magnetic Resonance

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a b s t r a c tWe present designs for compact, inexpensive and strong dipole permanent magnets aimed primarily at magnetic resonance applications where prepolarization and detection occur at different locations. Lowhomogeneity magnets with a 7.5 mm bore size and field up to nearly 2 T are constructed using low-cost starting materials, standard workshop tools and only few hours of labor -an achievable project for a student or postdoc with spare time. As an application example we show how our magnet was used to polarize the nuclear spins in approximately 1 mL of pure [13 C]-methanol prior to detection of its highresolution NMR spectrum at zero field (measurement field below 10 À10 T), where signals appear at multiples of the carbon-hydrogen spin-spin coupling frequency 1 J CH ¼ 140:7ð1Þ Hz.

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Design, fabrication and evaluation of a low-cost homogeneous portable permanent magnet for NMR and MRI

Cited by 25 publications

References 14 publications

Permanent magnet assembly producing a strong tilted homogeneous magnetic field: towards magic angle field spinning NMR and MRI

Permanent magnet assembly producing a strong tilted homogeneous magnetic field: towards magic angle field spinning NMR and MRI

Magnetically Enhanced Centrifugation for Industrial Use

Low-cost, pseudo-Halbach dipole magnets for NMR

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