一、引言次模拟和模拟裂变中子源用于研究链式反应系统的各种性质,所以这些中子源的能谱测量是很重要的。源材料、源包壳材料和工艺过程不同,中子源能谱也不同,因而在制作过程中,对源中子能谱的监测是十分必要的。这些中子源的能量一般是几百keV,这一能区连续中子能谱测量一直是很困难的。中子飞行时间法不适于本工作;阈探测器活化法在 I. INTRODUCTION Sub-simulations and simulations of fission neutron sources are used to study the various properties of chain reaction systems, so the energy spectrum measurements of these neutron sources are important. Source material, source cladding material and process are different, neutron source spectrum is also different, so in the production process, the source of neutron energy spectrum monitoring is very necessary. The energy of these neutron sources is typically a few hundred keV and it has been difficult to measure neutron energy spectrum continuously in this energy region. Neutron time of flight method is not suitable for this work; threshold detector activation method