A new technique to optimize the coil winding path for the arbitrarily distributed magnetic field and application to a helical confinement system

Abe, Mitsushi; Nakayama, Tsuneyoshi; Okamura, S.; Matsuoka, K.

doi:10.1063/1.1557073

Cited by 15 publications

(12 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The gradient coils were designed using the TSVD method [11,14,15]. In brief, the current surface of each gradient coil was discretized into a mesh of triangles.…”

Section: Methodsmentioning

confidence: 99%

“…Its major advantage is that magnetic field accuracies can be controlled by choosing an appropriate number of eigenmodes that make major contributions to the magnetic field. This concept has been demonstrated recently in the context of biplanar coils [11,14,15].…”

Section: Introductionmentioning

confidence: 95%

“…A key technology for designing oval gradients is the combination of matrix-inversion optimization techniques with discrete representations of the current surface [9][10][11][12][13][14][15]. This approach enables the design of arbitrarily shaped gradient coils, such as ultrashort coils, head gradient coils with highly asymmetric geometry, and shoulder-slotted gradient coils [13].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Oval gradient coils for an open magnetic resonance imaging system with a vertical magnetic field

Matsuzawa

Abe

Kose

et al. 2017

Journal of Magnetic Resonance

Self Cite

View full text Add to dashboard Cite

Existing open magnetic resonance imaging (MRI) systems use biplanar gradient coils for the spatial encoding of signals. We propose using novel oval gradient coils for an open vertical-field MRI. We designed oval gradients for a 0.3T open MRI system and showed that such a system could outperform a traditional biplanar gradient system while maintaining adequate gradient homogeneity and subject accessibility. Such oval gradient coils would exhibit high efficiency, low inductance and resistance, and high switching capability. Although the designed oval Y and Z coils showed more heat dissipation and less cooling capability than biplanar coils with the same gap, they showed an efficient heat-dissipation path to the surrounding air, which would alleviate the heat problem. The performance of the designed oval-coil system was demonstrated experimentally by imaging a human hand.

show abstract

“…The gradient coils were designed using the TSVD method [11,14,15]. In brief, the current surface of each gradient coil was discretized into a mesh of triangles.…”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Oval gradient coils for an open magnetic resonance imaging system with a vertical magnetic field

Matsuzawa

Abe

Kose

et al. 2017

Journal of Magnetic Resonance

Self Cite

View full text Add to dashboard Cite

show abstract

“…Design Method: Unfortunately, the same method as the zonal shim coil design could not be adopted for the radial shim coils of the MuHFS, because the length of the radial shim coils designed by the above method would be longer than the main A design method using a surface current potential and a singular value decomposition (SVD) [10] is employed for the shim coil design of the MuHFS. This method describes the shim coil winding patterns as the convolutions of eigen distributions, and it enables us to design the shim coils of arbitrary size.…”

Section: B Radial Shim Coil Designmentioning

confidence: 99%

Superconducting Magnet Design for the Hyperfine Structure Measurement of Muonium at the J-PARC

Sasaki

Sugano

Ohkubo

et al. 2013

IEEE Trans. Appl. Supercond.

View full text Add to dashboard Cite

A superconducting magnet system for a new muonium hyperfine structure, MuHFS, measurement at J-PARC is being developed. This experiment requires a magnetic field strength of 1.7 T with high homogeneity below 1 ppm. The overall mechanical design including helium and vacuum vessels was almost completed. In order to evaluate the influence of coil vibration on the error field, the modal analysis was performed. The conceptual design of superconducting shim coils was carried out. The zonal and radial shim coils were designed by using the conventional spherical harmonics method and the singular value decomposition method, respectively.

show abstract

“…The same kind of the problem is found in nuclear fusion device designs, and DUCAS 15 was developed to handle it. DUCAS calculates current potential 16 (CP) or MM density distributions on arbitrary surfaces using a regularization of the truncated singular value decomposition 17 (TSVD).…”

Section: Introductionmentioning

confidence: 97%

Passive Shimming of MRI Static Magnetic Field Using Regularization of Truncated Singular Value Decomposition

Abe¹

2017

magn reson med sci

Self Cite

View full text Add to dashboard Cite

Purpose:To develop a new shimming calculation method, which can calculate iron piece placements rapidly to make the magnetic field homogeneous at intended homogeneity and then to make the shimming working time short.Materials and Methods:The shimming calculation yields magnetic moment (MM) distribution, which is calculated by the truncated singular value decomposition (SVD) from the measured magnetic field. The MM distribution is described by a superposition of eigenmodes obtained by SVD of a response matrix from the moment distributions to magnetic fields at the field of view (FOV). The homogeneity is regulated by a truncation number of the superposed eigenmodes. The magnetic moments are converted into iron volumes with the assumption of saturated magnetization and the iron pieces are placed according to the calculation results. Since the SVD calculation can be done in advance, the computational time at the shimming site is short.Results:Trial applications on a 0.5T magnetic resonance imaging (MRI) magnet were done using the new shimming calculation method, which was proved to work well. However, since the iron piece volumes had tolerances, the work was repeated until enough homogeneity was obtained. As a result, an intended homogeneity of 8.9 ppm (peak-to-peak) on 40 cm diameter spherical surface was successfully obtained from measured homogeneity of 543 ppm with short computational and working time.Conclusion:The test shimming work showed that the developed shimming calculation method with truncated SVD regularization is applicable to the shimming work on the MRI magnets.

show abstract

A new technique to optimize the coil winding path for the arbitrarily distributed magnetic field and application to a helical confinement system

Cited by 15 publications

References 16 publications

Oval gradient coils for an open magnetic resonance imaging system with a vertical magnetic field

Oval gradient coils for an open magnetic resonance imaging system with a vertical magnetic field

Superconducting Magnet Design for the Hyperfine Structure Measurement of Muonium at the J-PARC

Passive Shimming of MRI Static Magnetic Field Using Regularization of Truncated Singular Value Decomposition

Contact Info

Product

Resources

About