Kim Junseong, Dong Fangliang, Kim Jaeyun, Bascunan Juan, Iwasa Yukikazu, Ackerman Jerome L, Park Dongkeun
Plasma Science and Fusion Center (PSFC), Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA.
Plasma Science and Fusion Center (PSFC), Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA.; Department of Electronic Materials Engineering, Kwangwoon University, Seoul 139-701, South Korea.
IEEE Trans Appl Supercond. 2024 Aug;34(5). doi: 10.1109/tasc.2024.3360024. Epub 2024 Jan 31.
The ability to perform magnetic resonance (MR) imaging or spectroscopy at significantly different magnetic field strengths during scanning holds great potential for expanding the range of contrast parameter options and obtaining high "superthermal" spin polarization for increased signal-to-noise ratio (SNR) or measuring certain spins at what would otherwise be impractically high RF frequencies. Enabling measurements at multiple field strengths heretofore has required either rapidly altering the strength of a resistive magnet with pulsed currents or shuttling the specimen between two field regions. We propose a novel approach to switching-field MR that we expect to be practical for live animal and ultimately human imaging. In this paper we propose the design of a liquid-helium-free fast switching-field MR magnet that can change the field very quickly in time (≤ 1 s) between significantly different field strengths. For this magnet, two types of NbSn wire are selected, and AC loss is measured by electrical method, and characteristics are analyzed.
在扫描过程中能够在显著不同的磁场强度下进行磁共振（MR）成像或光谱分析，对于扩展对比度参数选项范围以及获得高“超热”自旋极化以提高信噪比（SNR），或者在原本不切实际的高射频频率下测量某些自旋具有巨大潜力。迄今为止，要实现多场强测量，要么通过脉冲电流快速改变电阻磁体的强度，要么将样本在两个场区域之间移动。我们提出了一种新颖的切换场MR方法，预计该方法对于活体动物成像乃至最终的人体成像都具有实用性。在本文中，我们提出了一种无液氦快速切换场MR磁体的设计，该磁体能够在显著不同的场强之间在极短时间内（≤1 s）快速改变磁场。对于这种磁体，选择了两种类型的NbSn导线，并通过电学方法测量交流损耗并分析其特性。
