摘要
为实现应急监测设备的快速移动功能,将自制屏蔽室与电制冷便携式高纯锗γ能谱仪及其他必要配件组成便携式γ能谱测量系统,测试了自制屏蔽室的屏蔽效果及其对探测限的影响。选择气溶胶和碘盒作为模拟试验对象,使用该测量系统对模拟样品进行分析测量,为实际应急监测分析测量提供参考。试验发现,虽然屏蔽室侧壁由2.2 cm的铅和3 mm不锈钢构成,但可屏蔽50~2620 keV能量范围内79.3%的本底计数,从而降低测量探测限,有利于应急监测。消耗相同的应急监测资源,气溶胶样品中,特征人工放射性核素的探测限为mBq·m^-3量级,而碘盒样品中为50 mBq·m^-3量级以上。在核事故早期,建议先集中力量监测气溶胶样品,后续根据事故发展,再做综合考虑。
In order to achieve the fast moving function of emergency monitoring instruments,the homemade shielding chamber,portable high purity germanium gamma-ray spectrometer and other necessary equipment are combined to a portable gamma-ray spectrum measurement system.Meanwhile,shielding effect of home made shielding chamber and its influence on detection limit are tested.Aerosol and iodine box were selected as the simulated test objects,and the simulated samples were analyzed and measured with the measurement sys tem,so as to provide reference for practical emergency monitoring analysis and measurement.It is found that al though the shielding chamber is only 2.2 cm thick of lead and 3 mm stainless of steel,but it can shield 79.3%background counts in the energy range of 50~2620 keV,thus reduced the detection limit and facilitated emer gency monitoring.When using the same emergency monitoring resources,the detection limit level of anthropo genic radionuclides in aerosol samples is mBq?m^-3,while that in iodine samples is more than 50 mBq?m^-3.In the early stage of the nuclear accident emergency,it is suggested to concentrate on aerosol samples monitoring first,and then make comprehensive consideration according to the development of the accident.
作者
陈文涛
陈万良
李灵娟
Chen Wentao;Chen Wanliang;Li Lingjuan(Guangdong Environmental Radiation Monitoring Center,Guangzhou 510300,China)
出处
《核安全》
2019年第5期68-72,78,共6页
Nuclear Safety
关键词
应急监测
便携式高纯锗γ能谱仪
屏蔽测试
模拟应用
emergency monitoring
portable high purity germanium gamma-ray spectrometer
shielding test
simulation application
