填充LiF-CaF2:Eu共晶粉体的有机-无机复合闪烁体制备与表征OA

Thermal neutron technology is widely applied in many fields,such as homeland security,nuclear non-proliferation,nuclear energy development,industrial nondestructive testing,and nuclear physics research.However,existing commercially available thermal neutron detection materials currently still face many developmental challenges in terms of detection performance and manufacturing costs.In this study,a series of organic-inorganic composite scintillators sensitive to thermal neutrons was prepared via solid-state reaction by uniformly dispersing 0-20%(in mass)of LiF-CaF2:Eu eutectic powder in organic polystyrene matrixes.X-ray diffraction patterns,scanning electron microscope morphologies,and elemental distributions of the synthesized LiF-CaF2:Eu eutectic powder were analyzed.The radioluminescence and optical transmittance of the prepared composite scintillators were evaluated,and comparisons were made between LiF-CaF2:Eu eutectic powder and LiF-CaF2:Eu mixed powder as inorganic additives.Using cadmium difference method and pulse shape discrimination technologies,the thermal neutron detection performance of composite scintillators loaded with LiF-CaF2:Eu(natural Li abundance)and 6LiF-CaF2:Eu(95%enriched 6Li)eutectic powder was systematically investigated.Compared to composites filled with LiF-CaF2:Eu mixed powder,those filled with LiF-CaF2:Eu eutectic powder exhibited better optical transmittance and higher radioluminescence intensity,which increased with the addition of more eutectic powder.Increasing the abundance of 6Li can effectively improve thermal neutron detection efficiency,and figure of merit for thermal neutron/gamma discrimination in composite scintillators can reach 2.64.As a promising novel scintillator for thermal neutron detection,the composite scintillators loaded with LiF-CaF2:Eu eutectic powder show excellent thermal neutron detection and thermal neutron/gamma discrimination.