一、引言在研究链式反应系统的各种性质时,常常用到具有类似裂变中子能谱的中子源。模拟裂变中子源主要由~(210)Po的α粒子轰击F,Be,Li,B等轻元素产生中子,随着靶元素成份以及结构的差异,中子能谱也不完全相同。应本院同位素处的要求,我们测量了一模拟裂变中子源的能谱,其源强约10~4n/s,靶成份为天然Li 24.16%,F66.14%,B 9.4%, I. INTRODUCTION In studying the various properties of chain reaction systems, neutron sources with similar fission neutron spectra are often used. The simulated fission neutron source mainly produces neutrons from light elements such as F, Be, Li and B by ~ (210) Po alpha particles. The neutron energy spectra are not exactly the same with the composition and structure of target elements. At the isotope location of our institute, we measured the energy spectrum of a simulated fission neutron source with a source intensity of about 10 ~ 4n / s, a target composition of 24.16% for natural Li, F66.14% for B, 9.4% for B,