Design and Modeling of a Radiofrequency Coil Derived from a Helmholtz Structure

Ghaly, S. M. A.; Al-Snaie, K. A.; Ali, Andreas M.

doi:10.48084/etasr.2683

Cited by 7 publications

(6 citation statements)

References 20 publications

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“…The structure has a reduced dimension compared to the wavelength, so it is possible to apply the law of Biot-Savart and the principle of superposition to obtain the total field [9] on their axis [10]. The magnetic field of a circular loop of N turns whose plane of the coil is centered at z=+R/2 (field B 1 (z)), is written [11][12] as:…”

Section: Calculation Of the B 1 Magnetic Fieldmentioning

confidence: 99%

Design and Testing of a Radiofrequency Ellipsoidal Helmholtz Coil in Contrast with a Circular Pair for Nuclear Magnetic Resonance

Al-Snaie

2023

Eng. Technol. Appl. Sci. Res.

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The design and testing of a Helmholtz prototype probe with a relatively homogeneous radiofrequency field that can be used for MRI are presented in this paper. It consists of two coaxial separately tuned ellipsoidal rings of wire in a symmetric arrangement. The developed ellipsoidal structure is tested experimentally in free space and is compared with the results obtained with an equivalent circular standard Helmholtz coil. Complete electrical modeling of the coils taking into account all couplings (inductive and capacitive) is studied. The proposed ellipsoidal Helmholtz coil provides better performance in terms of field homogeneity, efficiency, and quality factor. The width of the lobe at 10% for the ellipsoidal coil is 20% bigger. Moreover, a significant improvement in the quality factor is observed in free space. Also, the efficiency is increased by 37%. Finally, the Signal to Noise Ratio (SNR) of the ellipsoidal coil is higher than that of the circular coil.

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Section: Calculation Of the B 1 Magnetic Fieldmentioning

confidence: 99%

Design and Testing of a Radiofrequency Ellipsoidal Helmholtz Coil in Contrast with a Circular Pair for Nuclear Magnetic Resonance

Al-Snaie

2023

Eng. Technol. Appl. Sci. Res.

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“…In this experiment, four ASBR reactors [8] were used, with an effective volume of 2 L, and electrified coils [9] were set outside the reactors to control the magnetic field intensity. In the experiment, the average magnetic field strengths in the four reactors were controlled to be 0 mT, 35 mT, 50 mT and 80 mT, respectively.…”

Section: Test Materials and Devicesmentioning

confidence: 99%

Influence Law and Mechanism of Magnetic Field on Accumulation of Nitrite Nitrogen in Denitrification Process

Yan

Jia

et al. 2022

Advances in Transdisciplinary Engineering

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A magnetic short-range denitrification reactor was constructed by using an external magnetic field, the influence of magnetic field on the accumulation characteristics of nitrite nitrogen in the denitrification system was studied, and the mechanism of magnetic field was analyzed. The study found that the magnetic field helps to increase the accumulation of nitrite nitrogen, and when the strength of the external magnetic field is 50 mT, the nitrite nitrogen can reach 35 mg/L. The magnetic field improves the stability of the nitrite nitrogen accumulation process, and has a certain inhibitory effect on the entire denitrification process, but has a greater impact on the NO2– to N2 reaction process.

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“…To calculate the electromagnetic field (B 1 ) produced by the proposed square and circular Helmholtz structures which consist of two symmetrical elements and have small dimensions compared to the wavelength, the superposition principle can be applied to obtain the total field as indicated in (2) and ( 5) for circular and square patterns [11][12][13]. The simulation code for the double square coil is programmed in MATLAB for a typical input data of I=1A, d=2.77cm, a=5cm, N=1, and µ 0 =4π×10 -7 mkgs -2 A -2 .…”

Section: Field Calculation and Pattern Plotmentioning

confidence: 99%

Design, Simulation, Modeling, and Implementation of a Square Helmholtz Coil in Contrast with a Circular Coil for MRI Applications

Ghaly

Khan

2019

Eng. Technol. Appl. Sci. Res.

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This paper focuses on Helmholtz-type coils that can produce a second-order homogeneity field to be used for Magnetic Resonance Imaging (MRI) applications. A Helmholtz coil is a device used for producing a region of a nearly uniform magnetic field. It consists of two identical magnetic coils that are placed symmetrically along a common axis, one on either side of the experimental area, separated by a distance equal to the radius of the circular coil and half-length of the side of the square coils. Each coil carries an equal electrical current flowing in the same direction. The main objective of this article is to calculate the magnetic field provided by the coils at any point in space and to show and compare the uniform magnetic field induced by the square and circular Helmholtz coils. With the aid of MATLAB simulation tool, mathematical equations are simulated to demonstrate the axial magnetic field produced by one and two loops. Also, the design and simulation of electrical modeling for square and circular Helmholtz coils are performed using PSPICE. Finally, these coils are realized and tested experimentally, and the results for square and circular Helmholtz coils are compared.

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Design and Modeling of a Radiofrequency Coil Derived from a Helmholtz Structure

Cited by 7 publications

References 20 publications

Design and Testing of a Radiofrequency Ellipsoidal Helmholtz Coil in Contrast with a Circular Pair for Nuclear Magnetic Resonance

Design and Testing of a Radiofrequency Ellipsoidal Helmholtz Coil in Contrast with a Circular Pair for Nuclear Magnetic Resonance

Influence Law and Mechanism of Magnetic Field on Accumulation of Nitrite Nitrogen in Denitrification Process

Design, Simulation, Modeling, and Implementation of a Square Helmholtz Coil in Contrast with a Circular Coil for MRI Applications

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