Development of High-precision Cryogenic Nuclear Magnetic Resonance Probe Based on the Technology of Liquid Nitrogen Flow Control

The cryogenic Nuclear Magnetic Resonance (NMR) probe is significant for the study of the cryogenic samples. In this paper, a cryogenic probe is proposed which is used for low-field NMR detection based on the technology of liquid nitrogen flow control. The probe structure is designed, simulated in order to improve the temperature uniformity and the efficiency of the temperature variation. Experiments are undertaken to verify the simulation results. The probe proposed can be applied as a portable sensor in the detection environment of -55°C to room temperature. The temperature controller can be preset to the target sample temperature and then the temperature drift can be kept below 0.5°C for a long time. In conclusion, the cryogenic NMR probe proposed has the characteristics of uniform temperature distribution, high accuracy of temperature control and high efficiency of temperature variation.