keV能区中子注量率测量初级标准装置研制

由于大多数中子探测器在keV能区处于共振能区，截面数据无法精确已知，无法作为中子注量率测量初级标准装置。⁶Li在keV能区的截面精确已知，本文以此设计了一种包含⁶LiF转换体的硅半导体探测器系统（LiF-SSD探测器），建立了keV能区中子参考辐射场中子注量率测量初级标准装置。利用SRIM和TRIM程序估算了LiF-SSD探测器的计数率；基于Geant4开发了探测器响应计算程序，给出了中子能量为27.4 keV的探测器脉冲幅度计算谱；利用⁴⁵Sc(p,n)-⁴⁵Ti反应，测量了27.4 keV中子能量点的探测器脉冲幅度谱，测量结果与理论计算谱符合较好。

Development of Primary Standard Detector for Neutron Fluence Rate Measurement in keV Region

Many types of neutron detectors are resonant in keV region, and the cross section is not accurately known. Therefore, it can’t be used as primary standard detector for neutron fluence rate measurement in keV region. The cross section of ⁶Li is accurately known in this energy region, and the LiF-SSD detector system was designed which consists of ⁶LiF conversion and Si semiconductor detector. The primary standard detector of neutron fluence rate measurement in keV region was established. The programs of SRIM and TRIM were used to evaluate the count rate of the LiF-SSD detector. The response of LiF-SSD detector calculation program was developed based on Geant4. The pulse height distribution of 27.4 keV neutron was calculated. Based on the reaction of ⁴⁵Sc(p, n)-⁴⁵Ti, the pulse height distribution of 27.4 keV neutron was measured, and it is close to calculation result.