Advanced field shimming technology to reduce the influence of a screening current in a REBCO coil for a high-resolution NMR magnet

被引：28

作者：

Iguchi, S. ^{[1
,2
]}

Piao, R. ^{[1
,3
]}

Hamada, M. ^{[4
]}

Matsumoto, S. ^{[5
]}

Suematsu, H. ^{[6
]}

Takao, T. ^{[2
]}

Saito, A. T. ^{[3
]}

Li, J. ^{[3
]}

Nakagome, H. ^{[3
]}

Jin, X. ^{[1
]}

Takahashi, M. ^{[1
]}

Maeda, H. ^{[1
]}

Yanagisawa, Y. ^{[1
,3
]}

机构：

[1] RIKEN, Ctr Life Sci Technol, Yokohama, Kanagawa 2300045, Japan

[2] Sophia Univ, Fac Sci & Technol, Yotsuya 1028554, Japan

[3] Chiba Univ, Grad Sch Engn, Chiba 2368522, Japan

[4] Japan Superconductor Technol Inc, Kobe, Hyogo 6512271, Japan

[5] Natl Inst Mat Sci, Sperconducting Wire Unit, Tsukuba, Ibaraki 3050003, Japan

[6] JEOL RESONANCE Inc, Akishima, Tokyo 1968558, Japan

来源：

SUPERCONDUCTOR SCIENCE & TECHNOLOGY | 2016年 / 29卷 / 04期

基金：

日本科学技术振兴机构;

关键词：

compact super-high field NMR; high-resolution NMR; REBCO coil; field inhomogeneity; screening current; shimming; ferromagnetic shim; 400 MHZ NMR; 1; GHZ; OPERATION;

D O I：

10.1088/0953-2048/29/4/045013

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

This paper describes a field shimming technology to obtain a spatially homogeneous magnetic field required for a high-resolution nuclear magnetic resonance (NMR) magnet under the influence of a screening current in a (RE) Ba2Cu3O7-x (REBCO) coil. Use of REBCO inner coils is one solution to realize a super-high field (>23.5 T, 1 GHz) NMR magnet. However, a REBCO coil generates a large amount of field error harmonics due to the inhomogeneous coil winding introduced by a thin tape conductor. In addition, the performance of a field correction coil and outer superconducting (SC) shim coils are significantly reduced due to the shielding effect of the screening current in the REBCO coil. Therefore, conventional shimming technology using SC shim coils and room temperature shim coils cannot adequately compensate those field error harmonics and high-resolution NMR measurements are not possible. In the present paper, an advanced field shimming technology including an inner SC shim coil and a novel type of ferromagnetic shim were installed in a 400 MHz low-temperature SC/REBCO NMR magnet. The inner SC shim coil and the ferromagnetic shim compensated for the reduction in the performances of the field correction coil and the SC shim coils, respectively. The field error harmonics were greatly compensated with the technology and a high NMR resolution <0.01 ppm was obtained. The results from the present work suggest an optimal shimming procedure for a super-high field NMR magnet with high-temperature superconductors inner coils, i.e. the best mix of shims.

引用

页数：12

共 12 条

[11] Influence of tissue conductivity anisotropy on EEG/MEG field and return current computation in a realistic head model: A simulation and visualization study using high-resolution finite element modeling
Wolters, CH
Anwander, A
Tricoche, X
Weinstein, D
Koch, MA
MacLeod, RS
NEUROIMAGE, 2006, 30 (03) : 813 - 826
[12] CRYSTALLOGRAPHIC SITE DISCRIMINATION IN ALUMINOPHOSPHATE MOLECULAR-SIEVES BY SOLID-STATE NMR - INFLUENCE OF THE FIELD-DEPENDENT ISOTROPIC 2ND-ORDER QUADRUPOLAR SHIFT ON HIGH-RESOLUTION AL-27 DOR NMR
GROBET, PJ
SAMOSON, A
GEERTS, H
MARTENS, JA
JACOBS, PA
JOURNAL OF PHYSICAL CHEMISTRY, 1991, 95 (24): : 9620 - 9622

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