Measurement of Reaction Rate Ratio of Capture to Fission and Relative Production Fraction of Excited-to Ground-States of Am241

利用京都大学临界装配仪（kua），测量了Am241和Np237的裂变反应和俘获反应，光谱指数分布广泛。(1) KUCA的计数设备和中子场的制备(2)Am241裂变截面的精确测量（实验误差<3%）(3)Np237裂变截面的精确测量（实验误差<3%）(4)利用最新的核数据库对这些实验进行精确分析。从目前的结果来看，最新的库仍然高估了两种核素的裂变截面约20%，这在先进反应堆的设计和研究中有待改进。

Fission reaction and capture reactions of Am241 and Np237 were measured in various cores with widely distributed spectrum indices by using the Kyoto University Critical Assembly (KUCA) as follows. (1) Preparation of a counting equipment and neutron fields in KUCA (2) Accurate measurement (experimental error <3%) of fission cross sections of Am241 (3) Accurate measurement (experimental error <3%) of fission cross section of Np237 (4) Precise analysis of those experiments by using the newest nuclear data libraries.From the present results, it was found that the newest libraries still overestimates the fission cross section of both nuclides about 20% which should be improved for design or research of the advanced reactors.