Zhang, Zhekai, Yi Jiang, Haiya Pi, Hongbin Chen, Chaoyang Liu, Jiwen Feng, and Maili Liu. “THz-Enhanced Dynamic Nuclear Polarized Liquid Spectrometer.” Journal of Magnetic Resonance 330 (September 2021): 107044.
https://doi.org/10.1016/j.jmr.2021.107044.
Dynamic nuclear polarization (DNP) technology can be utilized to dramatically enhance NMR signal. In this paper, we report on the development of a self-constructed 5 T DNP spectrometer for liquid samples and the 13C DNP enhancement achieved with this spectrometer. The DNP spectrometer is comprised of a wide-bore superconducting magnet, a home-made console, a dual resonance probe and a self-built 140 GHz microwave source for the spectrometer. Specifically, a microwave source of traveling wave tube (TWT) amplifier has been developed, which can provide a maximum power output of 4.4 W and a wide frequency tuning range of 1 GHz. The excellent performance of our built liquid-state DNP spectrometer is verified by the observation of more than 100-fold DNP enhancement of the 13C NMR signal for liquid 13CCl4 sample. Our result shows the superiority of DNP technology in the liquid-state high-field NMR spectrometer.