Characterization of a neutron-beta counting system with beta-delayed neutron emitters
Characterization of a neutron-beta counting system with beta-delayed neutron emitters
复制标题
具有 β 延迟中子发射器的中子 β 计数系统的表征
DOI：
10.1016/j.nima.2015.10.082
复制
发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Agramunt J
中科院分区：
文献类型：
--
作者：
Agramunt J
一种用于测量 β 延迟中子发射概率的新检测系统已使用具有众所周知的 β 延迟中子发射特性的裂变产物进行了表征。该装置由 BELEN-20、一个 4 π 中子计数器、20 个排列在大型聚乙烯中子慢化器内的 3 He 正比管、一个用于 β 计数的薄硅探测器和一个自触发数字数据采集系统组成。使用具有不同中子发射窗口的缓发中子前驱体可以研究能量依赖性对中子、β和β中子速率的影响。蒙特卡罗模拟很好地再现了观察到的效果。讨论了这种依赖性对中子发射概率准确性的影响。获得了重要的缓发中子前驱体 137 I 的中子发射概率的新准确值，P n= 7.76 (14)%。
A new detection system for the measurement of beta-delayed neutron emission probabilities has been characterized using fission products with well known β-delayed neutron emission properties. The setup consists of BELEN-20, a 4 π neutron counter with twenty 3 He proportional tubes arranged inside a large polyethylene neutron moderator, a thin Si detector for β counting and a self-triggering digital data acquisition system. The use of delayed-neutron precursors with different neutron emission windows allowed the study of the effect of energy dependency on neutron, β and β–neutron rates. The observed effect is well reproduced by Monte Carlo simulations. The impact of this dependency on the accuracy of neutron emission probabilities is discussed. A new accurate value of the neutron emission probability for the important delayed-neutron precursor 137 I was obtained, P n= 7.76 (14)%.