Development of Single-domain Annular REBCO Bulk Superconductors for Compact Cryogen-free NMR

Sakai, Naomichi; Nariki, S.; Teshima, Eiichi; Morita, Mitsuru; Hirabayashi, I.; Nakamura, Takashi; Itoh, Yoshitaka; Yoshikawa, Masaaki; Utsumi, Hiroaki

doi:10.2221/jcsj.46.131

Cited by 16 publications

(5 citation statements)

References 11 publications

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“…The linewidth of the NMR spectrum was about 228 kHz (~1850 ppm) [15]. The homogeneity of the HTS bulk magnets was further improved [16] and we reported the first MR images using an HTS bulk magnet in 2011 [17]. The homogeneity of the magnetic field for the MRI magnet was 37 ppm peak-to-peak in the central cylindrical region with 6.2 mm diameter and 9.1 mm length.…”

Section: Introductionmentioning

confidence: 94%

Development of a superconducting bulk magnet for NMR and MRI

Nakamura

Tamada

Yanagi³

et al. 2015

Journal of Magnetic Resonance

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112

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A superconducting bulk magnet composed of six vertically stacked annular single-domain c-axis-oriented Eu-Ba-Cu-O crystals was energized to 4.74 T using a conventional superconducting magnet for high-resolution NMR spectroscopy. Shim coils, gradient coils, and radio frequency coils for high resolution NMR and MRI were installed in the 23 mm-diameter room-temperature bore of the bulk magnet. A 6.9 ppm peak-to-peak homogeneous region suitable for MRI was achieved in the central cylindrical region (6.2 mm diameter, 9.1 mm length) of the bulk magnet by using a single layer shim coil. A 21 Hz spectral resolution that can be used for high resolution NMR spectroscopy was obtained in the central cylindrical region (1.3 mm diameter, 4 mm length) of the bulk magnet by using a multichannel shim coil. A clear 3D MR image dataset of a chemically fixed mouse fetus with (50 μm)(3) voxel resolution was obtained in 5.5 h. We therefore concluded that the cryogen-free superconducting bulk magnet developed in this study is useful for high-resolution desktop NMR, MRI and mobile NMR device.

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Section: Introductionmentioning

confidence: 94%

Development of a superconducting bulk magnet for NMR and MRI

Nakamura

Tamada

Yanagi³

et al. 2015

Journal of Magnetic Resonance

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112

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“…Gd-QMG bulks do not appear to be suitable for-achievingextreme homogeneous magnetic field due to the large paramagnetic moment of Gd ion. Eu-Ba-Cu-O materials are suitable for NMR/MRI magnets, since smaller paramagnetic moment of Eu ion improves the field homogeneity in the bulk [51][52][53][54][55]. The fabrication technology of Gd-QMG is applicable to the Eu-system.…”

Section: Optimizing the Re Elements For Specific Applicationsmentioning

confidence: 99%

Performance and applications of quench melt-growth bulk magnets

Nariki¹,

Teshima²,

Morita³

2016

Supercond. Sci. Technol.

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This paper describes the progress in quench melt-growth (QMG) bulk magnets, developed by the Nippon Steel & Sumitomo Metal Corporation, which consist of single crystalline RE123 phase and finely dispersed RE211 particles. QMG bulks can trap high magnetic fields. The field-trapping ability of QMG bulks is largely increased with an improvement in its Jc and size, promising the realization of various applications such as flywheel energy-storage systems, ship motors, NMR/MRI spectrometers, wind-power generators and so on. Intensive research has revealed that the optimal RE element is different depending on application requirements. Gd-QMG bulk is the most promising material for several high-field engineering applications. The trapped magnetic field of Gd-QMG bulk 60 mm in diameter at 77 K is twice as large as that of Y-QMG bulk with a similar size due to its excellent Jc properties. The large Gd-based QMG bulks up to 150 mm in diameter are fabricated by incorporating the RE compositional gradient method. Compact NMR/MRI spectrometers are one of the promising applications of bulk superconductors. Eu-QMG bulks are suitable for NMR magnets. NMR applications require extremely homogeneous magnetic fields. In the Eu-system, the small paramagnetic moment of a Eu ion compared to a Gd ion improves the field homogeneity in the bulk. For the application of current leads, Dy-based QMG is available by utilizing a low thermal conductivity.

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“…Therefore, a compact NMR system with high resolution comparable to conventional NMRs with an SCM can be realized only by using superconductor bulk magnets. Although the high B T of REBaCuO bulks is very attractive for compact NMRs, they intrinsically have an inhomogeneous fourfold symmetric field distribution [17]. This occurs because the REBaCuO bulk has four growth sector regions and growth sector boundaries due to the facet growth by the top-seeded melt growth method.…”

Section: Introductionmentioning

confidence: 99%

Detection of ¹H NMR signal in a trapped magnetic field of a compact tubular MgB₂ superconductor bulk

Takahashi¹,

Naito²,

Nakamura³

et al. 2021

Supercond. Sci. Technol.

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We measured 1H nuclear magnetic resonance (NMR) spectra from silicon rubber in a magnetic field trapped by a compact tubular MgB2 superconductor bulk magnet (60 mm outer diameter, 40 mm inner diameter, and 60 mm height) which was magnetized by field-cooled magnetization from an applied field, B a p p , of 0.4778 T at 20 K. The sharpest 1H NMR spectrum of the resonant frequency, f R , of 20.314 MHz, which corresponded to a field strength of 0.4771 T, was observed at 1 mm below the center of the bore of the MgB2 tube. The homogeneity of the trapped field was within 100 ppm between z = −2 and +2 mm along the central z-axis, which was evaluated by the position-dependent f R . No change in the trapped field was observed for about 25 d, which corresponded to a decay rate of less than 0.1 ppb h−1. The obtained results suggest that the MgB2 bulk magnet is a promising candidate for a magnetic pole in an NMR apparatus.

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Development of Single-domain Annular REBCO Bulk Superconductors for Compact Cryogen-free NMR

Cited by 16 publications

References 11 publications

Development of a superconducting bulk magnet for NMR and MRI

Development of a superconducting bulk magnet for NMR and MRI

Performance and applications of quench melt-growth bulk magnets

Detection of ¹H NMR signal in a trapped magnetic field of a compact tubular MgB₂ superconductor bulk

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Development of Single-domain Annular REBCO Bulk Superconductors for Compact Cryogen-free NMR

Cited by 16 publications

References 11 publications

Development of a superconducting bulk magnet for NMR and MRI

Development of a superconducting bulk magnet for NMR and MRI

Performance and applications of quench melt-growth bulk magnets

Detection of 1H NMR signal in a trapped magnetic field of a compact tubular MgB2 superconductor bulk

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Product

Resources

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Detection of ¹H NMR signal in a trapped magnetic field of a compact tubular MgB₂ superconductor bulk