海洋放射性核素γ能谱原位连续测量方法

In situ continuous measurement for gamma spectrum of marine radionuclide is an important part of the marine environment monitoring. Compared with sampling and analysis techniques, in situ continuous measurement method faces some problems, For example, spectral distortion, cosmic rays, peak shift, biofouling and none of calibration facility. The response function of gamma spectrum based on NaI(Tl) detector will be deduced using Monte Carlo. The influence of cosmic rays will be eliminated using material shielding and anticoincidence method. The peak shift will be corrected using two characteristic peaks. The biofouling will be prevented using ultrasonic cleaning. The calibration facility will be designed according to penetration distances of different kinds of radionuclide. The results of this project would be applied to the development of the in situ continuous measurement system and thus it is of great significance for pre-warning mechanism and emergency measures of marine radioactive contamination.

海洋放射性核素γ能谱原位连续测量是海洋环境监测的重要组成部分。与取样分析方法相比，原位连续测量存在谱线失真、宇宙射线影响、峰位漂移、生物附着和尚无标准刻度装置等问题。本项目拟通过蒙特卡洛模拟得出NaI(Tl)探测器在海水中的响应函数；拟采用物质屏蔽加反符合测量的方法消除宇宙射线的影响；拟采用双特征峰稳谱的方法消除峰位漂移；拟采用超声清洗的方法防止生物附着；拟采用不同能段的核素在海水中的穿透距离设计标准刻度装置。该方法可为后续的海洋放射性核素γ能谱原位连续测量系统的研制和解谱工作提供理论依据，对海洋放射性污染的预警和应急具有重要意义。

海洋放射性核素γ能谱原位连续测量是海洋环境监测的重要组成部分，开展海水原位γ能谱测量对海洋放射性污染的预警和应急具有重要意义。与取样分析方法相比，原位连续测量存在谱线失真、宇宙射线影响、峰位漂移、生物附着和尚无标准刻度装置等问题。本项目通过蒙特卡洛模得出NaI(Tl)探测器在海水中的响应函数；采用物质屏蔽加反符合测量的方法消除宇宙射线的影响；采用双特征峰稳谱的方法消除峰位漂移；采用超声清洗的方法防止生物附着；采用不同能段的核素在海水中的穿透距离设计标准刻度装置。本项目搭建的海水原位γ能谱传感器试验样机可有效地对海洋放射性污染进行现场测量，本项目对提高我国海洋环境的放射性核素的监测能力具有十分重要的实用价值。