快中子临界装置辐射损伤等效性实验测量

Radiation damage equivalent experimental measurement for fast neutron critical assembly

CFBR-Ⅱ堆是中子辐照实验指定模拟辐射源,某快中子临界装置在辐射效应研究中的作用越来越重要,为了准确评价利用上述平台开展的辐射效应研究结果,需要确定二者的辐射损伤等效系数。利用双极晶体管直流增益倒数与中子注量的线性关系,开展辐射损伤等效性研究。分析了辐射损伤等效系数的影响因素,从实验原理和工程实现的角度建立了效应参数和场量参数的控制方法,采用损伤常数平均的方式进行数据处理,首次获得了快中子临界装置与CFBR-Ⅱ堆的辐射损伤等效系数为1.19,不确定度为3.53%,满足了应用需求。

China Fast Burst Reactor-Ⅱ is the specified radiation source for neutron irradiation experiments, while the fast neutron critical assembly becomes more and more important in the study of radiation effect. The radiation damage equivalent coefficient between the two ones should be determined in order to accurately evaluate the radiation effect by using the fast neutron critical assembly. The silicon bipolar transistors are used as displacement damage monitors to obtain the damage constants of different neutron fields, according to the liner relationship between the reciprocal gain and neutron fluence. The factors influencing the radiation damage equivalent coefficient are analyzed. The experimental methods of controlling the effect parameters of semiconductor devices and the field parameters of the radiation source are established from experiment principle and engineering practice. The radiation damage equivalent coefficient averaging 1.19 between fast neutron critical assembly and CFBR-Ⅱis obtained for the first time by data processing, with the uncertainty of 3.53%, which meets the application requirements.