To obtain multiple monoenergetic neutron sources and realize the on-site calibration of radiation monitoring equipment for nuclear-involved places,the structural characteristics and neutron source features of D-T neut...To obtain multiple monoenergetic neutron sources and realize the on-site calibration of radiation monitoring equipment for nuclear-involved places,the structural characteristics and neutron source features of D-T neutron tube were analyzed;Monte Carlo method was adopted to simulate the effect of interaction between typical materials and different energy neutrons;multilayered shielding materials were combined and optimized to acquire the optimal scheme to shield the neutron sources from the neutron tube.On the base,a tapered alignment filtration construction was designed and Monte Carlo method was employed to simulate the effect of alignment construction.The result showed that the tapered alignment filtration construction can create monoenergetic neutrons including14.1 MeV,0.18 MeV and thermal neutrons and demonstrated good monochrome performance which provides multiple monoenergetic sources for the on-site calibration.展开更多
To obtain a small-angle monoenergetic neutron source,a shielding collimator device is designed for the neutron source generated by a neutron tube.The device is divided into the collimator and the capture cave.The coll...To obtain a small-angle monoenergetic neutron source,a shielding collimator device is designed for the neutron source generated by a neutron tube.The device is divided into the collimator and the capture cave.The collimator is made of three layers of stainless steel and borated polyethylene and is used to constrain neutrons in a small angle.The capture cave is used to increase the number of times neutron inelastic scattering occurs in the opposite direction of the radiation field,thereby reducing the proportion of scattered neutrons in the radiation field.Material thickness,aperture size,and the optimum structure of the capture cave were simulated using MCNP.The design features a neutron emission angle within a range of 3° and neutron fluxes in the radiation field,which are higher by two orders of magnitude than those outside the radiation field.This research has practical value for the generation of monoenergetic small-angle neutron sources and neutron applications.展开更多
文摘To obtain multiple monoenergetic neutron sources and realize the on-site calibration of radiation monitoring equipment for nuclear-involved places,the structural characteristics and neutron source features of D-T neutron tube were analyzed;Monte Carlo method was adopted to simulate the effect of interaction between typical materials and different energy neutrons;multilayered shielding materials were combined and optimized to acquire the optimal scheme to shield the neutron sources from the neutron tube.On the base,a tapered alignment filtration construction was designed and Monte Carlo method was employed to simulate the effect of alignment construction.The result showed that the tapered alignment filtration construction can create monoenergetic neutrons including14.1 MeV,0.18 MeV and thermal neutrons and demonstrated good monochrome performance which provides multiple monoenergetic sources for the on-site calibration.
文摘To obtain a small-angle monoenergetic neutron source,a shielding collimator device is designed for the neutron source generated by a neutron tube.The device is divided into the collimator and the capture cave.The collimator is made of three layers of stainless steel and borated polyethylene and is used to constrain neutrons in a small angle.The capture cave is used to increase the number of times neutron inelastic scattering occurs in the opposite direction of the radiation field,thereby reducing the proportion of scattered neutrons in the radiation field.Material thickness,aperture size,and the optimum structure of the capture cave were simulated using MCNP.The design features a neutron emission angle within a range of 3° and neutron fluxes in the radiation field,which are higher by two orders of magnitude than those outside the radiation field.This research has practical value for the generation of monoenergetic small-angle neutron sources and neutron applications.
