Measurement of 248cm/252Cf Spontaneous Prompt Fission Neutron Spectrum

用飞行时间方法测量200keV－12MeV能区内248Cm和252Cf自发裂变瞬发中子谱，以国际原子能机构推荐的252Cf自发裂变瞬发中子谱为标准，可以免去探测器效率刻度的问题并消除系统误差，提高测量精度.实验用一个微型电离室作为裂变碎片探测器，两个芪晶体中子探测器测量中子及一套基于微机的CAMAC系统组成的飞行时间测量谱仪，在一个空旷的测量室内完成的.飞行距离分别为32，50和100cm，经过对数据的处理和分析给出了200keV－12MeV的中子能区内的实验数据.用Maxwell分布对实验数据进行拟合，得到的核温度为(1.401±0.006)MeV.In order to treat the waste material of nuclear power and develop new type of clean nuclear power, it is necessary to measure the neutron data of long half life nuclei existed in the waste material. The prompt spontaneous neutron spectrum is one of the most important nuclear data for new type nuclear power facilities as well as for understanding the mechanism of fission neutron emission. The measurements of 248Cm/252Cf spontaneous prompt fission neutron spectrum in the neutron energy range from 200keV to 12MeV were performed by using TOF method. A micro-ionization chamber was used as fission fragment detector and stibene crystal as neutron detector. The flying paths of neutrons for the measurements were 30cm, 50cm and 100cm respectively. The spontaneous prompt fission neutron spectrum of 248Cm was fitted by the Maxwellian distribution and the temperature was determined as(1.401±0.006)MeV in the corresponding neutron energy range.国家自然科学基金; 国家外国专家局资助项目中文核心期刊要目总览(PKU)中国科学引文数据库(CSCD)04304-3082