摘要
中子监测是辐射场所监测的常规项目之一,提高辐射监测仪的标校技术在确保监测质量方面显得尤为重要,针对辐射监测仪受现场和工作条件限制不能上溯至较高的国家计量标准进行校准的问题,提出了贮存场所辐射监测仪现场标校技术研究。为获得单能中子源,实现涉核场所的现场标校,分析了D-T中子管的结构特点和中子源特点,采用蒙特卡罗方法模拟了典型材料与不同能量中子的作用效果,将多层屏蔽材料进行组合优化,得到了屏蔽中子管中子源的最佳方案。在此基础上,设计了锥形准直过滤结构,利用蒙特卡罗方法模拟了准直结构作用效果。结果表明,锥形准直过滤结构可获得单色性能较好的14.1MeV、0.18MeV和热中子等单能中子,为现场标校提供了多个单能源。
The neutron monitoring is a regular project of nuclear involving places.It is particularly important to improve the calibration technology of radiation monitor for guaranteeing the quality of radiation monitoring.It is difficult for neutron monitor calibration in some circumstance as where the neutron monitor is restricted by the site so that it cannot be moved to trace to the upper grade national measurement standards.To solve this kind of problem,a radiation monitor on-site calibration technology study was put forward.In order to get single-energy neutron source and realize the radiation monitor on-site calibration technology,neutron source characteristics and structure characteristics of D-T neutron tube were analyzed,and the effects of typical shielding materials with different energy neutrons were analyzed by Monte Carlo method.The typical shielding materials were combined in different methods,and the optimum shielding scheme was obtain.On this basis,collimator and filter cone structures were designed and the filtering effects of different materials were simulated by Monte Carlo.Theresult shows that a number of monoenergetic neutrons with good monochromaticity such as 14.1MeV,0.18 MeV and thermal neutron can be obtained,which provides multiple monoenergetic neutron sources for the on-site calibration.
出处
《原子能科学技术》
EI
CAS
CSCD
北大核心
2014年第S1期768-772,共5页
Atomic Energy Science and Technology
关键词
中子管
蒙特卡罗
屏蔽
准直系统
neutron tube
Monte Carlo
shielding
collimator system
