Development Of Boron-coated MRPC Thermal Neutron Detector

With the development of nuclear energy, the application of the neutron technology and theconstruction of the next generation neutron facilities, the neutron detector and the neutron detectiontechnology were greatly improved. Meanwhile, because of the shortage of the helium-3,the researchof new thermal neutron detector has become a hot spot. The MRPC is developed in the nineties of thelast century, which has high detection efficiency, excellent performances of the resisting radiation andgood time resolution. Based on these advantages, the new type thermal neutron detector wasdeveloped by coating a layer of the thermal neutron convertor.According to the structure of the boron-coated MRPC thermal neutron detector, Monte Carloprograms were used. Maxwell program and Geant4were used to simulate the electric field of the airgap and the conversion efficiency of thermal neutron with different thickness of the neutron convertorrespectively. The conversion efficiency of different neutron energy and the response of the gammarays were also studied. Theoretical calculations for the conversion efficiency of thermal neutronsagrees well with the simulation. Then, the optimum thickness of the neutron converter was acquired,The relationship between the time resolution, the intrinsic detection efficiency and the electric field,the proportion of the mixture gas were studied by Garfield. Based on the simulation, the proportion ofthe mixture and the optimal electric field were presented.At last, under the conventional and under balanced conditions, Monte Carlo method was used tosimulate the response of Compensated Neutron Logging technology, which uses the boron-coatedMRPC thermal neutron detector, the results indicate that the boron-coated MRPC thermal neutrondetector can be used for Compensated Neutron Logging.