基于卷积模型的核信号仿真  

Simulation nuclear signal generation program based on convolution model

作　　者：邵玮豪 梁勇飞[1] 杨朝文[1] 左晶鑫 宋云 SHAO Wei-Hao;LIANG Yong-Fei;YANG Chao-Wen;ZUO Jing-Xin;SONG Yun(College of Physics,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学物理学院,成都610065

出　　处：《四川大学学报（自然科学版）》2023年第1期122-127,共6页Journal of Sichuan University(Natural Science Edition)

基　　金：国家自然科学基金(U1967205)。

摘　　要：NaI(Tl)探测器因具有探测效率高和成本低等优点,常被用于核辐射能谱测量和核辐射监管等领域.由于实验条件等的限制,研究人员往往较难获取理想的实验核信号,虽然可以借助探测器的仿真信号来实现研究目的,但是常规的探测器单指数或双指数模型和实际采集到的核信号模型存在一定的差异,需要一种更为精准的数学模型对探测器输出信号进行描述.我们通过对探测器信号形成过程分析,将探测器视为线性时不变系统,探测器各个部分响应的总卷积即为输出的核信号模型.本文建立的探测器输出信号卷积模型,结合实测伽玛源的幅度分布规律和相邻脉冲时间间隔分布规律,可以提供更精确的NaI(Tl)探测器输出信号,以便用于伽玛能谱测量算法研究;通过调节脉冲间隔时间大小,可以仿真不同计数下探测器输出信号的堆积情形,以便用于堆积信号还原算法研究.经过与伽玛辐射源的对比测试,该仿真信号与真实探测器输出信号一致,既避免了研究人员接触放射源,提高辐射防护安全性,又为开展数字化核信号处理算法研究及能谱算法研究提供了极大的便利性.Due to the advantages of high detection efficiency and low cost,NaI(Tl)detectors are often used in the fields of nuclear radiation energy spectrum measurement and nuclear radiation supervision.Due to the limitations of experimental conditions,it is often difficult for researchers to obtain the ideal experimental nuclear signal.Although the simulation signal of the detector can be used to achieve the research purpose,there are certain differences between the conventional detector single exponential or double exponential model and the actual nuclear signal model,and a more accurate mathematical model is needed to describe the detector output signal.Through the analysis of the detector signal formation process,the detector is regarded as a linear time-invariant system,and the total convolution of the responses of each part of the detector is the output kernel signal model.Through the established detector output signal convolution model,combined with the amplitude distribution law of the measured gamma source and the adjacent pulse time interval distribution law,a more accurate NaI(Tl)detector output signal can be provided for use in gamma energy research on spectral measurement algorithms.By adjusting the pulse interval time,the accumulation situation of the detector output signal under different counts can be simulated,so as to be used for the research of the accumulation signal reduction algorithm.After the comparison test with the gamma radiation source,the simulated signal is consistent with the output signal of the real detector,which not only prevents researchers from contacting the radioactive source and improves the safety of radiation protection,but also provides great convenience for the research of digital nuclear signal processing algorithm and energy spectrum algorithm.

关 键 词：NAI(TL)探测器 卷积模型 仿真核信号 

分 类 号：TL8[核科学技术—核技术及应用]