A Double-resonance Probe Designed For Enhancing ~1H Nuclear Magnetic Resonance Signal

Dynamic nuclear polarization is a technique based on electron nuclear spin polarization,which can enhance NMR sensitivity hundreds of times.The two main disadvantages of high field DNP technology are small sample size and serious microwave heating.A dual resonant probe designed to achieve increased sample size while reducing heating effects for a particular application.Firstly,the principle of magnetic resonance is introduced,and the dynamic nuclear polarization technique is briefly introduced.The dynamic nuclear polarization spectrometer(0.06T),the whole magnet,emission system,receiving system,shimming system,master control and computer system and probes are briefly described.In the aspect of probe,a resonant cavity with BLGR form is adopted.It is an open deformation structure of cylindrical cavity.It uses TE mode in cylindrical cavity and operates at L band.The main feature of BLGR resonator is that the magnetic field can be concentrated in the direction of the cylinder axis as much as possible,and the electric field can be distributed between the bridge layer and the loop layer as much as possible.In the double resonance probe design and implementation work,implementation allows testing of liquid sample volume can reach 1mL,the maximum diameter of the sample can reach 10 mm,while reducing the heat effects of the double resonance probe,and the realization of the microwave cavity stable frequency adjustable range of hundreds of megahertz.In the test results of dual resonance probe,200 times maximum 1H nuclear signal was enhanced,while the heating effect was smaller.At present,probes have been successfully put into use for gel related research work.