论文标题
快速场循环，超高场核磁松弛分散体
Fast-field-cycling, ultralow-field nuclear magnetic relaxation dispersion
论文作者
论文摘要
基于碱原子蒸气的光学抽气磁力计（OPM）是用于直流和低频AC磁性测量的超敏感设备。在这里，与快速场合循环硬件和高分辨率光谱检测结合使用，我们证明了OPM在量化核磁弛豫现象中的适用性。在NT到MT场范围内的松弛速率分散率可实现液态液态下极慢的分子运动相关性的定量研究，时间常数> 1 ms，并深入了解相应的松弛机制。 10-20 ft/$ \ sqrt {\ mathrm {hz}} $在10 Hz至5.5 kHz $^1 $ h larmor频率之间的敏感性，足以检测出$ 0.1 ml液体液体中的磁共振信号，以简单的中间含量的材料与内部或内部的核粉末相提并论。高分辨率光谱检测可以解决核旋转旋转旋转耦合耦合，从而进一步扩大了对化学系统的应用范围。讨论了有关在100 s $^{ - 1} $的放松率测量的预期限制。
Optically pumped magnetometers (OPMs) based on alkali-atom vapors are ultra-sensitive devices for dc and low-frequency ac magnetic measurements. Here, in combination with fast-field-cycling hardware and high-resolution spectroscopic detection, we demonstrate applicability of OPMs in quantifying nuclear magnetic relaxation phenomena. Relaxation rate dispersion across the nT to mT field range enables quantitative investigation of extremely slow molecular motion correlations in the liquid state, with time constants >1 ms, and insight into the corresponding relaxation mechanisms. The 10-20 fT/$\sqrt{\mathrm{Hz}}$ sensitivity of an OPM between 10 Hz and 5.5 kHz $^1$H Larmor frequency suffices to detect magnetic resonance signals from $\sim$0.1 mL liquid volumes imbibed in simple mesoporous materials, or inside metal tubing, following nuclear spin prepolarization adjacent to the OPM. High-resolution spectroscopic detection can resolve inter-nucleus spin-spin couplings, further widening the scope of application to chemical systems. Expected limits of the technique regarding measurement of relaxation rates above 100 s$^{-1}$ are discussed.
