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14MeV快中子具有强穿透力,14MeV快中子照相技术适用于大尺寸金属外壳内部结构,尤其是内部含氢材料等的检测,在某些样品质量检测中是唯一可行的技术手段,在国内处于起步阶段.采用D-T加速器为中子源,用ZnS(Ag)和聚丙烯均匀混合材料研制了快中子荧光屏,耦合科学级CCD数字成像系统,在加速器中子产额为4.3×1010～6.8×1010n/s之间,进行了14MeV快中子数字照相技术的初步实验研究.在物屏距离1cm时获取了聚丙烯、ZnS(Ag)材料1:1和1:1.5配比转换屏1,2,3和4min的积分曝光图像,对荧光屏相对效率进行了测量;在源屏距离为30cm时,获取了多种样品的14MeV快中子照相图像,分析获得了系统点扩散函数和调制传递函数.实验分析揭示14MeV快中子照相对含氢材料和金属材料都有一定的检测能力,聚丙烯、ZnS(Ag)材料1:1配比转换屏的效率优于1:1.5配比转换屏的效率,分辨率可以达到1mm左右,为深入进行14MeV快中子照相技术及其应用研究奠定了基础.
14MeV fast neutron has a strong penetrating power. The 14MeV fast neutron imaging technology is suitable for the detection of the internal structure of large-size metal enclosures, especially the internal hydrogen-containing materials, which is the only feasible technical measure in the quality inspection of some samples. The domestic is in the initial stage.Using DT accelerator as the neutron source, a fast neutron fluorescent screen was fabricated by using ZnS (Ag) and polypropylene homogeneously mixed materials, coupled with a scientific CCD digital imaging system, the neutron yield of the accelerator was 4.3 × 1010 ~ 6.8 × 1010n / s, a 14MeV fast neutron digital photogrammetry was carried out.The experimental results show that when the screen distance is 1cm, the ratio of 1: 1 and 1: 1.5 of the conversion material of ZnS (Ag) , 2, 3 and 4 min, respectively. The relative efficiency of the phosphor screen was measured. When the distance of the source screen was 30 cm, 14 MeV fast neutron images of various samples were obtained, and the system point spread function and modulation transfer Function.Experimental analysis revealed that the 14MeV fast neutron photogrammetry has certain ability to detect hydrogen-containing materials and metal materials. The efficiency of 1: 1 ratio conversion screen of polypropylene and ZnS (Ag) materials is better than that of 1: 1.5 ratio conversion screen The efficiency, resolution can reach about 1mm, for the deep Photographed 14MeV neutron technology and its application research foundation.