摘要
缪子多模态成像有效利用了宇宙线缪子与材料相互作用产生的散射信息以及产生次级诱发中子的缪子信息.为对缪子多模态成像图像质量进行分析,基于GEANT4程序设置了探测模型,从缪子多重库仑散射模块和缪子诱发中子模块两部分对探测模型可靠性进行了验证,开发了缪子多模态成像模拟程序,得到了重建图像.成像12 h可达到4 mm的空间分辨率,成像时间在小时量级可清晰分辨边长10 cm的^(235)U立方体和其他常见的高、中、低原子序数材料立方体.经过12 h成像时间,包覆模型的缪子散射成像图像会造成误判,但缪子多模态成像图像能够正确反映^(235)U材料存在.不同成像时间内,缪子多模态成像图像的结构相似性指标均优于单一成像方法成像图像.研究结果表明与缪子散射成像图像和诱发中子符合的缪子成像图像相比,缪子多模态成像图像有更好的成像质量,能够适应更复杂的成像场景,在特殊核材料的检测识别方面更有优势.
Both the information about the scattering of muons due to their interaction with material and the information about the material-stopped muons generating secondary induced neutrons effectively are used for multimodal imaging of muon.In order to evaluate the image quality of multimodal imaging of muon,the detection model is established based on Geant4 and the reliability of the detection model is verified.Both the multiple Coulomb scattering module and the muon induced neutron module prove to be reliable.The multimodal imaging simulation program is developed,and the images are reconstructed on the basis of the simulated data.Four imaging models are developed.The first model is a line pair model used to study the spatial resolution of reconstructed images with imaging time ranging from two hours to two weeks.The line pair model is composed of^(235)U and the length of each line pair is set to be 100 mm.The cross sections are set to be 4^(2),4^(2),6^(2),6^(2),10^(2),10^(2),20^(2),and 20^(2)mm^(2),respectively.The second model is a cube model used to study the material resolution of reconstructed images with imaging time ranging from one hour to twelve hours.The side length of each cube is 100 mm.The third model is the cladding model used to test the reliability of multimodal imaging images in complex shielding situations.The outermost layer is of lead,with the side length being 140 mm and the thickness 40 mm.The middle layer is of iron,with the side length being 100 mm and the thickness 40 mm.The innermost layer of^(235)U,with the side length being 60 mm.The last letter model is used to calculate the structural similarity of reconstructed images,with imaging time ranging from half an hour to twelve hours.The letter model is made of^(235)U and consists of cubes with side length of 50 mm.The letters“E”and“P”are made up of 16 cubes and 15 cubes respectively.The spatial resolution reaches 4 mm when imaging time is within 12 hours.The^(235)U and other common high-z,medium-z,and low-z material can be distinguished when imaging time is on the order of hours.Muon scattering imaging image of the cladding model will cause misjudgment.However,the multimodal imaging image can correctly reflect the existence of^(235)U.The structure similarity between the reconstructed image and the reference image in different imaging times proves that multimodal imaging has higher quality than single imaging method.The study indicates that the multimodal imaging of muon has better imaging quality,can adapt to more complex imaging scenes and has more advantages in the detection and recognition of special nuclear material than muon imaging method with single interaction information.
作者
霍勇刚
严江余
张全虎
Huo Yong-Gang;Yan Jiang-Yu;Zhang Quan-Hu(School of Nuclear Engineering,Rocket Force University of Engineering,Xi’an 710025,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2022年第2期31-40,共10页
Acta Physica Sinica
