keV 能区单能中子参考辐射场核反应靶设计

摘要

质子轰击中等质量靶核是产生keV能区单能中子的一种常用方法。选择45 Sc（p ，n）45 Ti反应中子源作为keV能区单能中子参考辐射场的中子源，利用 FloWizard软件模拟大束流条件下核反应靶的温度分布，分析了影响靶温度分布的主要因素。利用 Target程序模拟核反应靶出射中子能谱，分析了不同材料的散射中子本底。同时精细调节5SDH-2加速器端电压，测量了薄靶（Sc）的激发曲线，测量结果与NPL和PTB的接近。%The monoenergetic neutron calibration fields in keV region were established using 45 Sc(p ,n) 45 Ti reaction .The target temperature distribution on condition of high intensity was simulated by FloWizard program .The main factors which affect temperature distribution of target were analyzed .The neutron energy spectrum was simulated by Target program .And then the curve of proton energy vs neutron yield was measured using standard long counter by finely adjusting 5SDH-2 accelerator voltage .Neutron peaks corresponding to the resonances were observed ,which is similar with that of NPL and PTB .