The Development Of Miniature-NMR Experimental Instrument

Due to various reasons, people in china have little knowledge about NMR technology though it has been very mature. Firstly, china has few independent intellectual property rights of NMR technology while facing the foreign technology embargo. Secondly, it is difficult to popularize the NMR instrument because of its heavy weight and high price. A simplified and portable instrument is the urgent need to further popularize the NMR technology. In this paper, a miniature and low-cost NMR experimental teaching instrument is designed for popularizing the NMR knowledge in undergraduate education, promoting the development of NMR technology in china.In this paper, the basic principal of NMR is described, and the NMR experiment method—CW NMR (continuous wave NMR) used here is introduced. Then, the analysis of the real device is given in detail, including the building of magnetic field, the design of circuit part and probe part. In magnetic part, the permanent magnet is chosen to construct the magnetic field. By comparing the advantages and disadvantages of several methods used to produce uniform magnetic field, a method used H type bipolar magnet to build the magnet field is proposed. And then, the specific magnetic circuit design and magnetic field simulation are discussed. In circuit part, a detection method based on marginal oscillator is used to improve the detection sensitivity, the principal of marginal oscillator is described, and the implementation of the oscillator and detection circuit is introduced. In probe part, a design of high SNR single-solenoid probe is described in detail.Finally, the experimental results and analysis of the system experiment is given.