一、引言自从M.Fleishman和S.Pons报告了他们实现冷核聚变后,引起了科学工作者的极大兴趣并掀起了热潮,我们于1989年4月也开始了这方面的研究工作。我们采用液体闪烁体耦合到光电倍增管来探测中子。ST-451液体闪烁体为φ10.5cm×5cm的圆柱体,用n-γ甄别技术排除γ射线讯号以降低本底。在设置探测阈窗从1.5～3.5 MeV中子能量时,它的平均本底计数为0.025中子/s,在中子源强度为5中子/s时, I. INTRODUCTION Since M.Fleishman and S.Pons reported that they had achieved great enthusiasm among scientists and scientists since their achievement of cold fusion, they also started a boom. We also started the research work in this area in April 1989. We use a liquid scintillator coupled to a photomultiplier tube to detect neutrons. The ST-451 liquid scintillator is a φ10.5 cm × 5 cm cylinder that uses gamma-ray scintillation technology to eliminate gamma-ray signals to reduce background. When the detection threshold window is set from 1.5 to 3.5 MeV neutron energy, its average background count is 0.025 neutron / s. When the neutron source intensity is 5 neutron / s,