TGS透射测量中探测器最佳几何参数的模拟设计研究  

Research on the Simulation Design of the Optimal Geometrical Parameters of the Detector in TGS Transmission Measurement

作　　者：付涛[1,2] 蒋嘉颖 史宠琳 徐艳洁 颜瑜成 FU Tao;JIANG JIAying;SHI Chonglin;XU Yanjie;YAN Yucheng(The Engineering&Technical College of Chengdu University of Technology,Leshan 614000,China;Southwestern Institute of Physics,Chengdu 610225,China)

机构地区：[1]成都理工大学工程技术学院,乐山614000 [2]核工业西南物理研究院,成都610225

出　　处：《核电子学与探测技术》2024年第2期269-276,共8页Nuclear Electronics & Detection Technology

摘　　要：层析伽马扫描技术(Tomographic Gamma Scanning,TGS)是目前先进的无损检测技术,能够通过透射测量等相关技术还原桶内各材料的衰减系数分布图像。在图像重建中探测器准直器的设计是保证重建图像质量的关键因素之一,本文采用蒙特卡罗工具包Geant4对TGS透射测量中前准直器(放射源准直器)和后准直器(探测器准直器)进行最佳几何参数模拟设计探究,分别寻找出两种准直器的最优几何参数,从而提高空间分辨率和准确度,可为TGS探测系统的设计提供一定的参考。结果表明,准直孔半径为0.66 cm,准直器深度为12 cm,作为放射源准直器的最佳参数;准直器半径为1.5 cm,屏蔽铅层为20 mm,准直器深度为5 cm,作为探测器的最佳几何参数。然而,本文模拟过程中也存在不足之处,比如粒子源抽样数较少,研究对象参数较少等,在后续工作中会进一步改进设计方案。TGS(Tomographic Gamma Scanning)is an advanced nondestructive testing technology,it can restore the internal attenuation coefficient distribution image of each material in the barrel by transmission scanning and other related techniques.In image reconstruction,as the collimator design of TGS system is one of the key factors to ensure the quality of the reconstructed image,this paper adopts the Monte Carlo tool kit Geant4 to simulate the geometric parameter design of the front collimator(radiation source collimator)and the back collimator(detector collimator)in the TGS transmission measurement.The optimal geometric parameters of the two collimators were found to improve the spatial resolution and accuracy,it can provide some reference for the design of TGS detection system.The results show that the radius of the collimating hole is 0.66 cm,and the depth of the collimator is 12 cm,which is the optimal parameter for the radiation source collimator;The radius of the collimator is 1.5 cm,the shielding lead layer is 20 mm,and the depth of the collimator is 5 cm,which is the optimal geometric parameter for the detector.However,there are also shortcomings in the simulation process of this article,such as fewer particle source samples and fewer parameters of the research object.This article will further improve the design scheme in subsequent work.

关 键 词：TGS 准直器 探测效率 峰康比 

分 类 号：TL812[核科学技术—核技术及应用]