基于碲锌镉探测器的高精度毫米级厚度测量技术研究  

Research on High-Precision mm-Level Thickness Measurement Technology Based on Cadmium Zinc Telluride Detector

作　　者：吕亮亮 刘军涛 李公平[1] 高旭东 宗畅 张正宏 孙淑义 潘小东[1] 李畅 LYU Liangliang;LIU Juntao;LI Gongping;GAO Xudong;ZONG Chang;ZHANG Zhenghong;SUN Shuyi;PAN Xiaodong;LI Chang(School of Nuclear Science and Technology,Lanzhou University,Lanzhou 730000,China)

机构地区：[1]兰州大学核科学与技术学院,兰州730000

出　　处：《同位素》2023年第3期285-294,共10页Journal of Isotopes

摘　　要：目前厚度测量精度不高或者测量方式复杂,为设计一套操作简单、高效、无损、适用范围广的高精度厚度测量装置,本研究利用^(241)Am放射源和碲锌镉(CZT)探测器,开发一套高精度厚度测量系统,同时提出采用测量条件补偿法实现样品无损、高精度在线测量。利用Geant4程序对厚度测量系统进行模拟设计,确定准直孔尺寸、源与探测器相对位置和屏蔽层厚度等关键参数。利用搭建的厚度测量系统测量纸张、圆台型样品、陶瓷和高速钢等样品。结果表明,该系统对厚度精度在百微米量级时,可以实现高效、实时在线厚度测量;当对测量精度要求提高时,通过延长测量时间、采用测量条件补偿法等,可实现高精度测量。对于1 mm厚的物质,测量精度可达1μm;该系统长时间工作稳定,24 h内相对标准偏差约为0.057%。The accuracy of thickness measurement is not high or the measurement method is too complicated at present.It is of great significance to design a set of high-precision thickness measurement device with simple operation,high efficiency,non-destructive measurement and wide application range.In this paper,a high-precision thickness measurement system is developed by using^(241)Am radioactive source and cadmium zinc telluride(CZT)detector,and a measurement condition compensation method is proposed to achieve non-destructive and high-precision online measurement of samples.The Geant4 program package is used to simulate the design of a high-precision thickness measurement system,and the influence of key parameters such as the size of the collimation hole,the relative position of the source and the detector,and the thickness of the shielding layer are determined.Use the built high-precision thickness measurement system to measure samples such as paper,circular truncated cone sample,ceramics and high-speed steel.The experimental results show that the system can achieve high-efficiency,online thickness measurement when the thickness accuracy is on the order of 100 microns;when the measurement accuracy is required to increase,high-precision measurement can be achieved by extending the measurement time and using the measurement condition compensation method.,for example,for a material with a thickness of 1 mm,the measurement accuracy can reach 1μm;at the same time,the system works stably for a long time,and the relative standard deviation within 24 h is about 0.057%.

关 键 词：高精度厚度测量 无损测量 碲锌镉探测器 Geant4模拟程序 单能γ吸收法 

分 类 号：TL814[核科学技术—核技术及应用]