【摘要】 <正> 一、引言 裂变谱中子诱发²³⁵U裂变⁹⁹Mo累计产额一直存在较大分歧。首先,苏联在五十年代测量的两个结果就相差8％。以后的测量结果虽然差距减小,但仍分为两组,彼此相差5％;一组接近苏联的高值6.4,另一组接近并稍低於热中子诱发²³⁵U裂变的⁹⁹Mo累计产额6.14。在裂变产物产额的测量中,⁹⁹Mo往往被取作参考核,其产额数据的上述分歧,影响其他裂变产物产额的取值。因此,我们对其进行了测量。更多还原

【Abstract】 Gross fission product gamma-ray spectra are obtained using a large volume Ge(Li) detector,and then,the total energy peaks corresponding to 99Mo 739 keV and 95Zr 756 keV gamma-rays are analysed. The R value, which is the ratio of 99Mo relative cumulative yields for fast and thermal fission of 235U,are determined.Absolute cumulative yield of 99Mo is obtained based on the normalization of the R Value to the reference values of FPYs concerned.Up to now,the published data can be divided into two groups:the one,~6.40,and the other,~6.10.Our result,6.12(1±2.8%),agrees well with the latter.更多还原