Atomic Energy Science and Technology ›› 2021, Vol. 55 ›› Issue (8): 1472-1477.DOI: 10.7538/yzk.2020.youxian.0616

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Monte Carlo Simulation on Impact Factor of Scatter-photon in γ-ray Distance Detection

LIU Minqiang;LI Chen;DU Chuanhua;XU Xianguo;ZHU Xiaofeng;ZHAO Hongchao;DUAN Binghuang   

  1. Institute of Electrical Engineering, China Academy of Engineering Physics, Mianyang 621000, China; Nuctech Company Limite, Beijing 100086, China
  • Online:2021-08-20 Published:2021-08-20

γ射线测距中散射光子影响因素的蒙特卡罗模拟

刘珉强;李晨;杜川华;许献国;朱小锋;赵洪超;段丙皇   

  1. 中国工程物理研究院 电子工程研究所,四川 绵阳621000;同方威视技术股份有限公司,北京100086

Abstract: The gamma ray ranging technology based on scattered photons has the characteristics of high ranging accuracy, fast response speed, high reliability, small volume, light weight, etc., and is suitable for the height measurement with high precision in close range in harsh space environment. In this paper, the variation law of scattering photon energy and intensity under different conditions was simulated by MCNP program, and the relations between detection height, sourcedetector distance, γray energy, target thickness, target material, backscattering peak photon energy and intensity were analyzed for the specified principle model. The backscattering peak photon energy is independent of target thickness (>10 cm) and target material, positively correlated with ray energy and sourcedetector distance, and negatively correlated with the detection height. The photon intensity of the backscattering peak is independent of the target thickness (>10 cm), positively correlated with the detection height, and negatively correlated with ray energy, source-detector distance and target material. And for different target materials, the energy distribution interval of the simulated backscattering peak photon is consistent with that of the theoretical calculation, implying that the Monte Carlo simulation for gamma ray ranging technology is feasible and credible.

Key words: Monte Carlo simulation, γ-ray ranging, backscattering peak, photon energy, photon intensity

摘要: 基于散射光子的γ射线测距技术,具有测距精度高、响应速度快、可靠性高、体积小、重量轻等特点,适用于在苛刻空间环境中实现近距离高精度的高度测量。本文采用蒙特卡罗程序MCNP建立模型,模拟不同条件下散射光子的能量、强度的变化规律,分析了探测距离、源探距离、γ射线能量、靶目标厚度以及靶目标材料的变化对反散射峰光子能量与强度的影响,得出以下结论:反散射峰光子能量与靶目标厚度(>7 cm)、靶目标材料无关,与γ射线能量、源探距离正相关,与探测距离负相关;反散射峰光子强度与靶目标厚度(>7 cm)无关,与探测距离正相关,与γ射线能量、源探距离、靶目标材料负相关。对于不同靶目标材料,模拟计算的反散射峰光子能量分布区间与理论计算结果一致,证实本文γ射线散射光子测距技术的仿真方法可行、结果可信。

关键词: 蒙特卡罗模拟, γ射线测距, 反散射峰, 光子能量, 光子强度