Skin Effect Estimation in Radiofrequency Coils for Nuclear Magnetic Resonance Applications
Skin Effect Estimation in Radiofrequency Coils for Nuclear Magnetic Resonance Applications
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DOI：
10.1007/s00723-016-0780-x
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发表时间：
2016-04
影响因子：
1
通讯作者：
G. Giovannetti;G. Tiberi
中科院分区：
文献类型：
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作者：
G. Giovannetti;G. Tiberi
设计和开发专用射频（RF）线圈是核磁共振（NMR）应用中最大化信噪比（SNR）的基本任务。线圈电阻会降低SNR，应通过采用适当形状和横截面的导体将其降至最低。在RF下，导体电阻由于集肤效应而增加，集肤效应使电流主要分布在导体的表面上，而不是均匀地分布在横截面上。特别地，在矩形形状的导体中，电流密度集中在高曲率区域中并且增加导体电阻，而圆形导体呈现较低的电阻并且表现出性能的改进，特别是在低频调谐线圈中。本文总结了不同的方法来估计导体损耗的RF线圈的NMR应用，其性能强烈影响数据的质量。由于不同横截面积的导体对线圈损耗的影响并没有得到普遍认可，也没有在许多其他线圈设计工作中得到解决，因此我们相信该综述可能会对NMR线圈设计和开发领域的研究人员产生兴趣。
The design and development of dedicated radiofrequency (RF) coils is a fundamental task to maximize the signal-to-noise ratio (SNR) in nuclear magnetic resonance (NMR) applications. Coil resistance reduces the SNR and should be minimized by employing conductors of appropriate shape and cross section. At RF, the conductor resistance is increased due to the skin effect, which distributes the current primarily on the surface of the conductor instead of uniformly over the cross section. In particular, in rectangular shape conductors the current density is concentrated in the high-curvature area and increases the conductor resistance, while rounded conductors present lower resistance and demonstrate improvements in performance especially in low-frequency tuned coils. This paper summarizes the different methods for estimating conductor losses in RF coils for NMR applications, whose performance strongly affect quality data. Because the impact to coil loss from conductors with different cross-sectional area is not something generally recognized and nor addressed in many other coil design works, we believe the review could be interesting for researchers working in the field of NMR coil design and development.