The Na I(Tl) scintillation detector has a number of unique advantages, including wide use, high light yield,and its low price. It is difficult to obtain the decomposition of instrument response spectrum because of lim...The Na I(Tl) scintillation detector has a number of unique advantages, including wide use, high light yield,and its low price. It is difficult to obtain the decomposition of instrument response spectrum because of limitations associated with the Na I(Tl) scintillation detector's energy resolution. This paper, based on the physical process of c photons released from decay nuclides, generating an instrument response spectrum, uses the Monte Carlo method to simulate c photons with Na I(Tl) scintillation detector interaction. The Monte Carlo response matrix is established by different single energy γ-rays with detector effects. The Gold and the improved Boosted-Gold iterative algorithms have also been used in this paper to solve the response matrix parameters through decomposing tests,such as simulating a multi-characteristic energy c-ray spectrum and simulating synthesized overlapping peaks cray spectrum. An inversion decomposition of the c instrument response spectrum for measured samples(U series, Th series and U–Th mixed sources, among others)can be achieved under the response matrix. The decomposing spectrum can be better distinguished between the similar energy characteristic peaks, which improve the error levels of activity analysis caused by the overlapping peak with significant effects.展开更多
闪烁体探测器γ能谱测量中,闪烁光子的产生、传输及光电器件收集、倍增均对能谱的分辨有巨大影响。为了精确模拟闪烁体探测器的能量分辨,采用蒙特卡洛模拟软件GEANT4建立了一套模型,分别对Na I(TI),LaBr_3:0.5%Ce^(3+)闪烁体探测器测量...闪烁体探测器γ能谱测量中,闪烁光子的产生、传输及光电器件收集、倍增均对能谱的分辨有巨大影响。为了精确模拟闪烁体探测器的能量分辨,采用蒙特卡洛模拟软件GEANT4建立了一套模型,分别对Na I(TI),LaBr_3:0.5%Ce^(3+)闪烁体探测器测量能量为662 ke V的γ射线能谱进行模拟,获得的结果与实验测试结果能够很好的符合,验证了建立模型合理性与可靠性,为闪烁体的设计提供了一套更精确的开发工具。展开更多
在核应急条件下,需要对水源放射性进行快速检测。本文利用降低本底和能谱分析的方法,通过优化物理设计,给出系统快速检测水中放射性核素的能力。系统采用Ф50 mm×200 mm NaI(TI)晶体作为伽马探测器,结合蒙特卡罗模拟计算,优化屏蔽...在核应急条件下,需要对水源放射性进行快速检测。本文利用降低本底和能谱分析的方法,通过优化物理设计,给出系统快速检测水中放射性核素的能力。系统采用Ф50 mm×200 mm NaI(TI)晶体作为伽马探测器,结合蒙特卡罗模拟计算,优化屏蔽装置和探测系统。能谱分析采用两次拟合算法,对18 L含有^(137)Cs的放射性标准溶液进行检测,实验结果达到设计要求。展开更多
基金supported by National Natural Science Foundation of China(No.11365001)National Major Scientific Equipment Development Projects(No.041514065)+1 种基金Natural Science Foundation of Jiangxi(No.20161BAB201035)Fundamental Science on Radioactive Geology and Exploration Technology Laboratory,East China Institute of Technology(No.RGET1316)
文摘The Na I(Tl) scintillation detector has a number of unique advantages, including wide use, high light yield,and its low price. It is difficult to obtain the decomposition of instrument response spectrum because of limitations associated with the Na I(Tl) scintillation detector's energy resolution. This paper, based on the physical process of c photons released from decay nuclides, generating an instrument response spectrum, uses the Monte Carlo method to simulate c photons with Na I(Tl) scintillation detector interaction. The Monte Carlo response matrix is established by different single energy γ-rays with detector effects. The Gold and the improved Boosted-Gold iterative algorithms have also been used in this paper to solve the response matrix parameters through decomposing tests,such as simulating a multi-characteristic energy c-ray spectrum and simulating synthesized overlapping peaks cray spectrum. An inversion decomposition of the c instrument response spectrum for measured samples(U series, Th series and U–Th mixed sources, among others)can be achieved under the response matrix. The decomposing spectrum can be better distinguished between the similar energy characteristic peaks, which improve the error levels of activity analysis caused by the overlapping peak with significant effects.
文摘研究了封装反射层材料对GAGG:Ce探测器光收集的影响,同时与Na I(TI)闪烁体探测器进行了详细的对比性实验,用137Cs、60Co标准源测量了γ能谱,对GAGG:Ce与Na I(TI)闪烁体探测器的温漂、能量线性及能量分辨率等性能指标重点进行了讨论。结果表明:GAGG:Ce探测器随温度漂移变化程度较大;能量线性好,线性相关度r为0.9999;对662 ke V的γ射线能量分辨率为7.8~8.0%。
文摘闪烁体探测器γ能谱测量中,闪烁光子的产生、传输及光电器件收集、倍增均对能谱的分辨有巨大影响。为了精确模拟闪烁体探测器的能量分辨,采用蒙特卡洛模拟软件GEANT4建立了一套模型,分别对Na I(TI),LaBr_3:0.5%Ce^(3+)闪烁体探测器测量能量为662 ke V的γ射线能谱进行模拟,获得的结果与实验测试结果能够很好的符合,验证了建立模型合理性与可靠性,为闪烁体的设计提供了一套更精确的开发工具。
文摘在核应急条件下,需要对水源放射性进行快速检测。本文利用降低本底和能谱分析的方法,通过优化物理设计,给出系统快速检测水中放射性核素的能力。系统采用Ф50 mm×200 mm NaI(TI)晶体作为伽马探测器,结合蒙特卡罗模拟计算,优化屏蔽装置和探测系统。能谱分析采用两次拟合算法,对18 L含有^(137)Cs的放射性标准溶液进行检测,实验结果达到设计要求。
