摘要
为实现对γ放射源的远距离快速定位,设计了一款NaI(Tl)晶体探测器阵列。基于蒙特卡罗方法,使用Geant4软件建模并开展数值模拟,采用高斯拟合算法和最小二乘原理,将放射源定位问题转化为拟合寻峰问题,通过对拟合参数的求解,实现了γ放射源的快速定位。然后,进一步研究了距离、发射粒子总数、射线能量、俯仰角及探测器数量对定位精度的影响。结果表明:当放射源位于探测器阵列平面内,到达探测器阵列的射线强度大于9个/cm^(2)时,定位误差小于1°;随着放射源位置相对于阵列平面的俯仰角增大,定位精度逐渐降低,当俯仰角小于30°时,平均绝对误差小于1°;通过增加探测器阵列的探测器数量,可以有效提高定位精度,当阵列的探测器数量由12增加至24时,不同俯仰角的定位精度均提高了42.9%以上,但也增加了阵列的质量、尺寸和成本,实际应用中需根据场景合理选择。
A NaI(Tl)crystal detector array was designed to enable rapid,long-range orien-tation of radioactive sources.Based on the Monte Carlo method,modeling and numerical simula-tions were performed with the Geant4 software.The problem of radioactive source orientation was transformed into a peak-fitting problem by applying a Gaussian fitting algorithm and the least-squares principle.By solving for the fitting parameters,rapid orientation ofγ-ray sources were successfullly achieved.Further research was conducted to examine the effects of various factors on positioning accuracy,including the distance between the source and the array,the total num-ber of emitted particles,γ-ray energy,the pitch angle of the source relative to the array plane,and the number of array detectors.The results show that when the radioactive source is located in the plane of the detector array and the intensity of the rays exceeds 9 rays/cm^(2),the positioning error is less than 1°.As the pitch angle of the source increases relative to the array plane,posi-tioning accuracy gradually decreases.When the pitch angle is less than 30°,the average absolute error is less than 1°.Positioning accuracy improves siginificantly with an increased number of de-tectors in the array.For instance,when the number of detectors increased from 12 to 24,the po-sitioning accuracies at different pitch angles improve by more than 42.9%.However,this improve-ment comes at the cost of increased array weight,size,and manufacturing cost.In practical appli-cations,the configuration should be selected based on specific operational requirement.
作者
孙威
陈洁
霍勇刚
姜仁强
李玉枝
SUN Wei;CHEN Jie;HUO Yonggang;JIANG Renqiang;LI Yuzhi(Rocket Force University of Engineering,Xi’an 710025,China;Characteristic Medical Center of Rocket Force,Beijing 100032,China;2nd Representative Office of Rocket Force Equipment Department in Mianyang Region,Mianyang 621000,China;Troops No.96033,Huaihua 148000,China)
出处
《火箭军工程大学学报》
2025年第4期85-94,共10页
Journal of Rocket Force University of Engineering
关键词
探测器阵列
高斯拟合算法
最小二乘原理
放射源定位
detector array
Gaussian fitting algorithm
least squares principle
radioactive source orientation
