【作者】 肖德涛； 赵桂芝； 肖拥军； 马光鼐；

【Author】 XIAO-Detao,ZHAO-Guizhi,XIAO-Yongjun,MA-Guangnai (School of Nuclear Science and Technology, Nanhua University, Hengyang 421001,China)

【机构】 南华大学核科学技术学院；

【摘要】 利用²²⁰Rn子体ThC’衰变产生的α粒子能量较氡及其子体衰变产生的α粒子能量都高的特点,发展了一种²²⁰Rn测量的吸收体方法。介绍了加吸收体甄别氡及实现²²⁰Rn直接测量的原理、研制的吸收体法被动累积测²²⁰Rn剂量计及其刻度方法。该剂量计测²²⁰Rn暴露量和介质表面²²⁰Rn析出率的刻度系数分别为R₀=0.0767cm^-2(kBq·m^-3·h)^-1和R=0.1301cm^-2(kBq·m^-3·h)^-1,当测量周期为7d,所用CR-39SSNTD本底径迹密度标准差S_T=1.6cm^-2时,其测²²⁰Rn浓度与²²⁰Rn析出率的探测下限分别为LLD_?=248.4Bq·m^-3和LLD_E=34.8mBq·m^-2·S^-1。²²⁰Rn累积测量的吸收体法在环境²²⁰Rn水平测量、室内²²⁰Rn及其子体水平分布测量和介质表面²²⁰Rn析出率测量中得到了应用。更多还原

【Abstract】 A integrated thoron measurement method with absorber is developed based on the characteristic of thorium C’ which emits a α particle with higher energy than those of α particles released from radon and radon progenies. The principles of discriminating radon and realizing thoron measurement with absorber, a passive and integrated thoron monitor studied and its calibration coefficent determination method are introduced. The calibration coefficients of the studied monitor are R₀=0.0767cm^-2(kBq·m^-3·h)^-1 for thoron exposure measurement and R=0.1301cm^-2(kBq·m^-3·h)^-1 for thoron exhalation rate measurement. The lower limits of detection are LLD_C=248.4Bq·m^-3 and LLD_E=34.8mBq·m^-2·s^-1 when the sampling period is 7 days and the deviation of background track densities of the adopted CR-39SSNTD is S_T=1.6cm^-2. The method is used for the measurement of environmental thoron concentrations, the distribution of indoor thoron and it’s progenies concentrations, and thoron exhalation rates on material surfaces.更多还原