Formation of a homogeneous magnetic field in spectrometer dipole magnet using permanent magnet

1992 ◽  
Vol 28 (1) ◽  
pp. 568-570 ◽  
Author(s):  
V.D. Borisov ◽  
V.S. Kashikhin ◽  
E.A. Lamzin ◽  
S.P. Potekhin ◽  
Y.P. Severgin ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Homogeneous Magnetic Field ◽  
Dipole Magnet

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

2010 ◽  
Vol 48 (12) ◽  
pp. 903-908 ◽  
Author(s):  
Dimitris Sakellariou ◽  
Cédric Hugon ◽  
Angelo Guiga ◽  
Guy Aubert ◽  
Sandrine Cazaux ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Homogeneous Magnetic Field ◽  
Magic Angle

Simulation and Optimization of a Permanent Magnet for Small-Sized MRI by Genetic Algorithm

2013 ◽  
Vol 341-342 ◽  
pp. 577-580
Author(s):  
Yi Yuan Cheng ◽  
Ling Xia ◽  
Wei He
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Homogeneous Magnetic Field ◽  
Main Magnetic Field ◽  
Resonance Imaging ◽  
Simulation And Optimization ◽  
Field Uniformity ◽  
Main Magnet ◽  
Magnetic Resonance Imaging Mri ◽  
The Magnetic Field

The main magnet produces the main magnetic field in the imaging area as one of the important parts of the magnetic resonance imaging (MRI) system. In a permanent MRI magnet, the widespread end effect causes a non-uniform magnetic field distribution and affects the imaging quality. In this paper, an H-type permanent magnet for small-sized MRI applications was designed; in particular, we added an optimized shimming ring outside the pole piece to improve the magnetic field uniformity. Genetic algorithms are used to solve the complex and nonlinear calculation of the magnetic field. The simulation results show that the magnet optimized by the proposed method generates a homogeneous magnetic field that can be easily implemented in practice.

scholarly journals Designing a structure of the magnetically active part of dipole electromagnets for the system of vertical convergence-separation of beams

2021 ◽  
Vol 2 (5 (110)) ◽  
pp. 14-22
Author(s):  
Andriy Getman
Keyword(s):  
Magnetic Field ◽  
Magnetic Induction ◽  
Homogeneous Magnetic Field ◽  
Heavy Ion ◽  
Active Part ◽  
Dipole Magnet ◽  
Assigned Value ◽  
Magnetic Parameters ◽  
The Third ◽  
The Stability

This paper reports the results of calculating the magnetic parameters for a direct dipole magnet in the system of vertical convergence-separation of particle beams of the upper and lower rings of the heavy-ion collider. An optimized variant of the yoke and superconducting winding structures has been obtained, providing for the assigned value of a homogeneous magnetic field inside the aperture at the minimized contributions of higher-order harmonics, average-integral along the length. The results from the analysis of the transverse projections of the magnetic induction obtained by 2D modeling of two variants of the design of the central cross-section of the dipole electromagnet are presented. The analysis results have established the dependence of the stability of magnetic parameters in the aperture of the electromagnet when the current in the winding changes on the volume of those yoke regions whose magnetization value is close to saturation. A 3D model of the magnetically active part has been built for two variants of the electromagnet design, and the values of the average-integral harmonics of transverse projections of magnetic induction in the aperture have been calculated. The relationship between the third average-integral harmonic of magnetic induction and the size lengths of the yoke and winding has been empirically established, making it possible to correct the heterogeneity of the transverse magnetic field in the aperture of the electromagnet. The results of optimization of the structure of the magnetically active part of the electromagnet are presented on the criteria for a minimum of the values of the average-integral coefficients of magnetic induction, carried out on the basis of correction of the initial geometric parameters of the yoke and winding. An improvement in the stability of magnetic parameters has been demonstrated, by 3 times, as well as a two-fold reduction in the contribution to the heterogeneity by the third average-integral harmonic when using a two-row arrangement of the winding turns inside the yoke in the design of the electromagnet

Analysis of magneto rheological elastomers for energy harvesting systems

2020 ◽  
Vol 64 (1-4) ◽  
pp. 439-446
Author(s):  
Gildas Diguet ◽  
Gael Sebald ◽  
Masami Nakano ◽  
Mickaël Lallart ◽  
Jean-Yves Cavaillé
Keyword(s):  
Magnetic Field ◽  
Energy Harvesting ◽  
Shear Strain ◽  
Magnetic Induction ◽  
Magnetic Particles ◽  
Homogeneous Magnetic Field ◽  
Electrical Signal ◽  
Harvesting Systems ◽  
Dc Bias ◽  
Magneto Rheological

Magneto Rheological Elastomers (MREs) are composite materials based on an elastomer filled by magnetic particles. Anisotropic MRE can be easily manufactured by curing the material under homogeneous magnetic field which creates column of particles. The magnetic and elastic properties are actually coupled making these MREs suitable for energy conversion. From these remarkable properties, an energy harvesting device is considered through the application of a DC bias magnetic induction on two MREs as a metal piece is applying an AC shear strain on them. Such strain therefore changes the permeabilities of the elastomers, hence generating an AC magnetic induction which can be converted into AC electrical signal with the help of a coil. The device is simulated with a Finite Element Method software to examine the effect of the MRE parameters, the DC bias magnetic induction and applied shear strain (amplitude and frequency) on the resulting electrical signal.

A novel analytical calculation of magnetic field in the slotted air gap of spoke-type permanent-magnet machines using conformal mapping

2020 ◽  
pp. 1-15
Author(s):  
Jianqi Li ◽  
Yu Zhou ◽  
Jianying Li
Keyword(s):  
Magnetic Field ◽  
Conformal Mapping ◽  
Permanent Magnet ◽  
Flux Density ◽  
Analytical Method ◽  
Electromotive Force ◽  
Analytical Calculation ◽  
Air Gap ◽  
Permanent Magnet Machines ◽  
Peak Value

This paper presented a novel analytical method for calculating magnetic field in the slotted air gap of spoke-type permanent-magnet machines using conformal mapping. Firstly, flux density without slots and complex relative air-gap permeance of slotted air gap are derived from conformal transformation separately. Secondly, they are combined in order to obtain normalized flux density taking account into the slots effect. The finite element (FE) results confirmed the validity of the analytical method for predicting magnetic field and back electromotive force (BEMF) in the slotted air gap of spoke-type permanent-magnet machines. In comparison with FE result, the analytical solution yields higher peak value of cogging torque.

Study of Reactance Evaluation Methods in Saturated Magnetic Field for Permanent Magnet Synchronous Motor

2006 ◽  
Vol 126 (12) ◽  
pp. 1722-1729 ◽  
Author(s):  
Akeshi Takahashi ◽  
Haruo Koharagi ◽  
Satoshi Kikuchi ◽  
Kazumasa Ide ◽  
Kazuo Shima
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Permanent Magnet Synchronous Motor ◽  
Synchronous Motor ◽  
Evaluation Methods

Notizen: Effect of Magnetic Field on Ascorbic Acid Oxidase Activity, I

1986 ◽  
Vol 41 (3) ◽  
pp. 355-358 ◽  
Author(s):  
V. S. Ghole ◽  
P. S. Damle ◽  
W. H.-P. Thiemann
Keyword(s):  
Magnetic Field ◽  
Ascorbic Acid ◽  
Homogeneous Magnetic Field ◽  
Acid Oxidase ◽  
High Substrate Concentration ◽  
Ascorbic Acid Oxidase ◽  
Rate Of Reaction ◽  
Substrate Concentrations ◽  
Burk Plot

A homogeneous magnetic field of 1.1 T strength exhibits a significant influence on the activity of the enzyme ascorbic acid oxidase in vitro. A Lineweaver-Burk plot of the reaction shows the typical pattern of a mixed-type inhibition, i.e. a larger rate of reaction at low substrate concentrations and a smaller rate of reaction at high substrate concentration than that of the control without magnetic field applied.

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