中文摘要：

加速器驱动的次临界系统（ADS）基准装置启明星1#在外推临界实验过程中,快热交界面探测器计数率与其他位置探测器计数率存在较大异常。本工作对该实验装置外推临界实验开展数值模拟,并对快热交界面的中子能谱进行详细计算,根据计算结果对探测器在外推临界实验中的计数率异常现象进行分析。结果表明,快热交界面能谱随燃料装载量的变化是引起探测器计数率异常的主要因素,这为今后快热耦合次临界实验装置开展中子学实验研究提供了理论依据。

英文摘要：

The neutron count rate of detector in fast-thermal boundary showed quite different performance in critical extrapolation experiment on Venus 1#,which was listed as a benchmark of accelerator driven sub-critical system（ADS）.In order to explain the abnormal phenomenon in experiment,numerical simulations of experiment and calculations of neutron spectrum in fast-thermal boundary were performed,analyses to the abnormal neutron count rate were also represented through calculations.The results indicate that neutron spectrum change during critical extrapolation is the main contributor to the abnormal performance of detector in experiment.This research work will supply theoretical basis for neutronics study on fast-thermal coupling sub-critical systems of the future.