Gan Zhehong, Kwak Hyung-Tae, Bird Mark, Cross Timothy, Gor'kov Peter, Brey William, Shetty Kiran
Center of Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, Tallahassee, FL 32310, USA.
J Magn Reson. 2008 Mar;191(1):135-40. doi: 10.1016/j.jmr.2007.12.008. Epub 2007 Dec 25.
Resistive and resistive-superconducting hybrid magnets can generate dc magnetic fields much higher than conventional superconducting NMR magnets but the field spatial homogeneity and temporal stability are usually not sufficient for high-resolution NMR experiments. Hardware and technique development addressing these issues are presented for high-resolution NMR at magnetic fields up to 40T. Passive ferromagnetic shimming and magic-angle spinning are used effectively to reduce the broadening from inhomogeneous magnetic field. A phase correction technique based on simultaneous heteronuclear detection is developed to compensate magnetic field fluctuations to achieve high spectral resolution.
电阻式和电阻-超导混合磁体能够产生比传统超导核磁共振磁体高得多的直流磁场,但场的空间均匀性和时间稳定性通常不足以用于高分辨率核磁共振实验。本文介绍了针对高达40T磁场下的高分辨率核磁共振,解决这些问题的硬件和技术发展。有效地使用了被动铁磁匀场和魔角旋转来减少非均匀磁场导致的展宽。开发了一种基于同时异核检测的相位校正技术,以补偿磁场波动,从而实现高光谱分辨率。