scholarly journals The Numerical Simulation of the Shielded Helmholtz Coils System Magnetic Field

2018 ◽  
Vol 155 ◽  
pp. 01038
Author(s):  
Ivan Zatonov ◽  
Pavel Baranov
Keyword(s):  
Magnetic Field ◽  
Numerical Simulation ◽  
Axial Direction ◽  
Magnetic Flux Density ◽  
Magnetic Field Inhomogeneity ◽  
Field Inhomogeneity ◽  
Functional Connection ◽  
Axial Coordinate ◽  
Helmholtz Coils ◽  
The Magnetic Field

This article describes the calculation of the magnetic field in the axial direction for the Helmholtz coil. The inhomogeneity of the magnetic field for this coil system is calculated. Authors defined the functional connection of the magnetic flux density in the system center from the antimagnetic shield thickness in two ways: iron and Finemet alloy shield. The dependency graph of the magnetic field inhomogeneity in the center of shielded Helmholtz coils system from the axial coordinate value is estimated

scholarly journals Magnetic field computation and simulation of the coil systems using Comsol software

2018 ◽  
Vol 160 ◽  
pp. 01006 ◽  
Author(s):  
Ivan Zatonov ◽  
Pavel Baranov ◽  
Andrey Kolomeycev
Keyword(s):  
Magnetic Field ◽  
Axial Direction ◽  
Calibration System ◽  
Method Of Calculation ◽  
Helmholtz Coils ◽  
Magnetic Field Homogeneity ◽  
Different Types ◽  
Field Homogeneity ◽  
Magnetic Field Computation ◽  
The Magnetic Field

The article considers the calibration system computation with the inhomogeneity of magnetic field less than 0.1 %. Method of calculation is described. The numerical simulation using finite-element analyze was made for such system as: Helmholtz coils, improved Helmholtz coils, four and six coils system. Authors made the calculation of the magnetic field homogeneity toward axial direction. Based on procure results, authors analyzed magnetic field homogeneity and compared different types of coil systems.

A Kind of Shimming Method for MRI

2014 ◽  
Vol 889-890 ◽  
pp. 230-233
Author(s):  
Xiao Bing Zhang
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Magnetic Field Inhomogeneity ◽  
Field Inhomogeneity ◽  
Open Mri ◽  
Precision And Accuracy ◽  
The Magnetic Field

This paper presents a shimming method for correct the magnetic field inhomogeneity generated by the permanent magnet biplanar open MRI magnets. After giving the explanation of the degree of the magnetic field inhomogeneity, the shimming principle and method are given. In order to guarantee the precision and accuracy of the magnetic field, a 3D moving flat is developed. The intensity of magnetic field is shown by the aid of the Excel, and the engineer can shim the magnetic field by interacting with the computer. After using the proposed method on a batch of permanent magnet biplanar open MRIs, the experiment results show that the proposed method is effective.

scholarly journals Improving chemical shift encoded water-fat separation using object-based information of the magnetic field inhomogeneity

2014 ◽  
Vol 73 (2) ◽  
pp. 597-604 ◽  
Author(s):  
Samir D. Sharma ◽  
Nathan S. Artz ◽  
Diego Hernando ◽  
Debra E. Horng ◽  
Scott B. Reeder
Keyword(s):  
Magnetic Field ◽  
Chemical Shift ◽  
Magnetic Field Inhomogeneity ◽  
Field Inhomogeneity ◽  
Object Based ◽  
The Magnetic Field

scholarly journals Magnetic field computation and simulation of the coil systems using Comsol software

2018 ◽  
Vol 158 ◽  
pp. 01032
Author(s):  
Ivan Zatonov ◽  
Pavel Baranov ◽  
Andrey Kolomeycev
Keyword(s):  
Magnetic Field ◽  
Axial Direction ◽  
Calibration System ◽  
Method Of Calculation ◽  
Helmholtz Coils ◽  
Magnetic Field Homogeneity ◽  
Different Types ◽  
Field Homogeneity ◽  
Magnetic Field Computation ◽  
The Magnetic Field

The article considers the calibration system computation with the inhomogeneity of magnetic field less than 0.1 %. Method of calculation is described. The numerical simulation using finite-element analyze was made for such system as: Helmholtz coils, improved Helmholtz coils, four and six coils system. Authors made the calculation of the magnetic field homogeneity toward axial direction. Based on procure results, authors analyzed magnetic field homogeneity and compared different types of coil systems.

scholarly journals Design of a New 1D Halbach Magnet Array with Good Sinusoidal Magnetic Field by Analyzing the Curved Surface

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2522
Author(s):  
Guangdou Liu ◽  
Shiqin Hou ◽  
Xingping Xu ◽  
Wensheng Xiao
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Permanent Magnet ◽  
Flux Density ◽  
Permanent Magnets ◽  
Air Gap ◽  
Curved Surface ◽  
Magnetic Flux Density ◽  
Sinusoidal Magnetic Field ◽  
The Magnetic Field

In the linear and planar motors, the 1D Halbach magnet array is extensively used. The sinusoidal property of the magnetic field deteriorates by analyzing the magnetic field at a small air gap. Therefore, a new 1D Halbach magnet array is proposed, in which the permanent magnet with a curved surface is applied. Based on the superposition of principle and Fourier series, the magnetic flux density distribution is derived. The optimized curved surface is obtained and fitted by a polynomial. The sinusoidal magnetic field is verified by comparing it with the magnetic flux density of the finite element model. Through the analysis of different dimensions of the permanent magnet array, the optimization result has good applicability. The force ripple can be significantly reduced by the new magnet array. The effect on the mass and air gap is investigated compared with a conventional magnet array with rectangular permanent magnets. In conclusion, the new magnet array design has the scalability to be extended to various sizes of motor and is especially suitable for small air gap applications.

scholarly journals Calculation of Transient Magnetic Field and Induced Voltage in Photovoltaic Bracket System during a Lightning Stroke

2021 ◽  
Vol 11 (10) ◽  
pp. 4567
Author(s):  
Xiaoqing Zhang ◽  
Yaowu Wang
Keyword(s):  
Magnetic Field ◽  
Time Derivative ◽  
Equivalent Circuit Model ◽  
Magnetic Flux Density ◽  
Induced Voltage ◽  
Lightning Stroke ◽  
Transient Magnetic Field ◽  
Lightning Current ◽  
Time Space ◽  
The Magnetic Field

An effective method is proposed in this paper for calculating the transient magnetic field and induced voltage in the photovoltaic bracket system under lightning stroke. Considering the need for the lightning current responses on various branches of the photovoltaic bracket system, a brief outline is given to the equivalent circuit model of the photovoltaic bracket system. The analytic formulas of the transient magnetic field are derived from the vector potential for the tilted, vertical and horizontal branches in the photovoltaic bracket system. With a time–space discretization scheme put forward for theses formulas, the magnetic field distribution in an assigned spatial domain is determined on the basis of the lightning current responses. The magnetic linkage passing through a conductor loop is evaluated by the surface integral of the magnetic flux density and the induced voltage is obtained from the time derivative of the magnetic linkage. In order to check the validity of the proposed method, an experiment is made on a reduced-scale photovoltaic bracket system. Then, the proposed method is applied to an actual photovoltaic bracket system. The calculations are performed for the magnetic field distributions and induced voltages under positive and negative lightning strokes.

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