Achievement of 1020MHz NMR
Publication date: July 2015
Source:Journal of Magnetic Resonance, Volume 256
Author(s): Kenjiro Hashi, Shinobu Ohki, Shinji Matsumoto, Gen Nishijima, Atsushi Goto, Kenzo Deguchi, Kazuhiko Yamada, Takashi Noguchi, Shuji Sakai, Masato Takahashi, Yoshinori Yanagisawa, Seiya Iguchi, Toshio Yamazaki, Hideaki Maeda, Ryoji Tanaka, Takahiro Nemoto, Hiroto Suematsu, Takashi Miki, Kazuyoshi Saito, Tadashi Shimizu
We have successfully developed a 1020MHz (24.0T) NMR magnet, establishing the world’s highest magnetic field in high resolution NMR superconducting magnets. The magnet is a series connection of LTS (low- T c superconductors NbTi and Nb3Sn) outer coils and an HTS (high- T c superconductor, Bi-2223) innermost coil, being operated at superfluid liquid helium temperature such as around 1.8K and in a driven-mode by an external DC power supply. The drift of the magnetic field was initially ± 0.8ppm/10h without the 2H lock operation; it was then stabilized to be less than 1ppb/10h by using an NMR internal lock operation. The full-width at half maximum of a 1H spectrum taken for 1% CHCl3 in acetone-d6 was as low as 0.7Hz (0.7ppb), which was sufficient for solution NMR. On the contrary, the temporal field stability under the external lock operation for solid-state NMR was 170ppb/10h, sufficient for NMR measurements for quadrupolar nuclei such as 17O; a 17O NMR measurement for labeled tri-peptide clearly demonstrated the effect of high magnetic field on solid-state NMR spectra.
Graphical abstract
Source:
Journal of Magnetic Resonance