0.57 MeV、1.0 MeV和1.5 MeV单能中子诱发<sup>235</sup>U裂变的产物产额绝对测量

0.57 MeV、1.0 MeV和1.5 MeV单能中子诱发²³⁵U裂变的产物产额绝对测量

摘要: ²³⁵U的裂变产物产额是核能应用和核物理研究中的重要基础数据。本工作应用高纯锗γ能谱法绝对测量了0.57、1.0 MeV和1.5 MeV中子诱发²³⁵U裂变的各能量点30个质量链的产额数据。样品的裂变率通过双裂变室监测，并利用蒙特卡罗（MCNP）模拟了辐照时样品的中子能谱，结果与国际上相应能量点数据在实验不确定度范围内吻合。本工作得到的产额数据澄清了原有数据最高16%的差异并将数据精度从国际上原有数据精度5%~7%提高到3%~5%。

Abstract: Fission product yields are fundamental nuclear data for nuclear energy applications and nuclear physics research. In this work, HPGe γ spectrometric technique is applied to absolutely measure the mass distributions from 0.57, 1.0 MeV and 1.5 MeV neutron induced fission of ²³⁵U, and more than 30 mass chain yields are obtained for each energy. The fission rate of uranium sample is monitored by a double fission chamber and its neutron spectrum is simulated via MCNP program. Comparing with the existing data of other lab, our results are in good agreement within the experimental uncertainties. The output data obtained in this work clarifies the difference of up to 16% in the original data and improves the data accuracy from 5%-7% of the original international data to 3%-5%.