基于缪致X射线的加速器缪子源三维成像模拟研究  

Simulation Study of 3D Imaging Using Accelerator Muon Source Based on Muonic X-rays

作　　者：冯春添 尹隆乡 罗思远 王克 王晓冬[1,2] FENG Chuntian;YIN Longxiang;LUO Siyuan;WANG Ke;and WANG Xiaodong(School of Nuclear Science and Technology,University of South China,Hengyang 421200,China;Key Laboratory of Advanced Nuclear Energy Technology Design and Safety,Ministry of Education,Hengyang 421200,China)

机构地区：[1]南华大学核科学技术学院,衡阳421200 [2]先进核能技术设计与安全教育部重点实验室,衡阳421200

出　　处：《核电子学与探测技术》2025年第2期172-179,共8页Nuclear Electronics & Detection Technology

基　　金：国家自然科学基金(No.12275120);湖湘青年英才(No.2022RC1202);湖南省自然科学基金(No.2021JJ20006);中国科学技术部(No.2020YFE0202001)。

摘　　要：缪致X射线是负缪子被原子核俘获后形成缪子原子经高激发态退激产生的特征X射线。其能量大小与原子序数有关,可通过采集特征X射线以探测空间中散装材料成分信息与位置信息,在考古学与行星科学样品检测分析中具有广阔的应用前景。为验证使用加速器缪子源对散装材料进行毫米级分辨率成像的可行性,本研究使用Geant4模拟了负缪子束对不同尺寸外形和元素种类的物体的打靶,利用缪致X射线的位置及动量信息通过径迹密度算法对靶物体中缪子原子的产生位置进行重建,并使用结构相似度(SSIM)对靶物体三维成像效果进行评估。结果表明,当靶材料原子序数高时成像效果较差,在二维成像图中可分辨10 mm厚铁块中相隔1 mm的铝块间隙,钛制圆锥、铁制球及铜制圆台三维重建图成像质量SSIM均值分别为0.84、0.715及0.637,成像质量良好。在缪致X射线成像领域该径迹密度成像方法可实现毫米级分辨率成像并实现靶物体三维重建,在定位低原子序数物质方面具有广阔的发展前景。Muonic X-rays are characteristic X-rays produced when a negative muon is captured by an atomic nucleus,forming a muonic atom that de-excites from a highly excited state.The energy of these X-rays is related to the atomic number,allowing the collection of characteristic X-ray energies to non-destructively detect the composition and location of bulk materials in space.This technique has broad applications in archaeology and planetary science sample analysis.To verify the feasibility of using an accelerator muon source for millimeter-resolution imaging of bulk materials,this study uses Geant4 to simulate the targeting of objects of various sizes,shapes,and elemental compositions with a negative muon beam.By utilizing the position and momentum information of the muonic X-rays,the generation locations of muonic atoms within the target are reconstructed using a track density algorithm.The quality of the 3D imaging of the target objects is evaluated using the Structural Similarity Index(SSIM).Results show that imaging quality is poorer for targets with higher atomic numbers.In the 2D imaging maps,gaps of 1 mm between aluminum blocks within a 10 mm thick iron block can be resolved.The average SSIM values for the 3D reconstructions of a titanium cone,an iron sphere,and a copper frustum are 0.84,0.715,and 0.637,respectively,indicating good imaging quality.This track density imaging method in the field of muonic X-ray imaging achieves millimeter-resolution imaging and enables 3D reconstruction of target objects,showing promising potential for locating low atomic number substances.

关 键 词：GEANT4 缪致X射线 成像 μ子原子 三维重建 

分 类 号：TL81[核科学技术—核技术及应用]