Study of Neutron Nuclear Data Relevant to Incineration of Transuranium Elements

超铀元素焚烧相关中子核数据研究

• 批准号: 04680234
• 负责人: OHSAWA Takaaki
• 金额: $ 1.47万
• 依托单位: Kinki University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04680234/
• 关键词: Transuranium element; Incineration; Nuclear data; Neutron; Fission

Nuclear data evaluation system based on adequate nuclear fission models was developed and applied for important actinides in order to provide basic data for the study of incineartion of transuranium nuclides.1.Evaluation of Fission Neutron Spectrum : New evaluation system for fission spectra was developed on the basis of the non-equitemperature Madland-Nix model previously proposed by the author. The special feature of the system is the following : : (a) Systematics of the fragment mass distribution was used to estimate the average fragment nucliders ; (b) Nuclear level density parameters a with inclusion of the shell effects were obatined by using the Ignatyuk model in stead of simple linear approximatio of the type a=A/C(A : mass number, C : adjustable parameter) ; (c) The total energy release of fission was calculated using the mass formula of Tachibana et al. ; (d) The energy dependence of the inverse cross section was taken into consideration ; (e) The total fission probability was decomposed into first-to fourth-chance fission components and the fission spectra from each stage were calculated to form the total spectrum. This system was used to provide evaluated fission spectra for U-233, -235, -238, Pu-239, Np-237, Am-241 etc.Analysis of Energy Dependence of Fission Neutron Multiplicity : The average fission neutron multiplicities for actinides were calculated using the above system. It was found that the results are dependent on the neutron binding energy data used as input.Analysis of Fission Cross Sections : A code was developed to break down the total fission cross section into its constituent (n, f)-, (n, nf)-, ・・・, (n, 4nf)-components. This program was applied in the procedure 1. (e) above.

为了给超铀核素的增感研究提供基础数据，建立了基于适当核裂变模型的核数据评价系统，并应用于重要的锕系元素。1.裂变中子谱评价：在作者提出的非等温Madland-Nix模型的基础上，建立了新的裂变谱评价系统。该系统的特点是：（a）用碎片质量分布的系统学方法估算平均碎片核素数;（B）用Ignatyuk模型代替简单的a=A/C型线性近似，得到考虑壳效应的核能级密度参数a（A：质量数，C：可调参数）：（c）用Tachibana等人的质量公式计算裂变释放的总能量：（d）考虑了反截面的能量依赖性;（e）将总裂变几率分解为第一至第四次机会裂变分量，计算每个阶段的裂变谱，形成总裂变谱。该系统已用于U-233、-235、-238、Pu-239、Np-237、Am-241等裂变能谱的估算。裂变中子多重数的能量依赖性分析：用该系统计算了锕系元素的平均裂变中子多重数。裂变截面分析：将裂变截面分解为（n，f）-，（n，nf）-，···，（n，4 nf）-四个分量。该程序应用于程序1。(e)以上

项目成果

Takaaki Ohsawa: "Evaluation of Fission Neutron Spectra for Minor Actinides" Proceedings of International Conference on Nuclear Data for Science and Technology. 2. 639-641 (1994)

Takaaki Ohsawa：“小锕系元素裂变中子谱的评估”国际科学技术核数据会议论文集。

Takaaki, Ohsawa et al.: "Evaluation of Fission Neutron Spectra for Minor Actinides" Proceedings of International Conference on Nuclear Data for Science and Technology. Vol.2. 639-641 (1994)

Takaaki、Ohsawa 等人：“小锕系元素裂变中子谱的评估”国际科学技术核数据会议论文集。

Takaaki Ohsawa: "Evaluation of Fission Neution Spectra for Minor Actinides" Proceedings of International Conference on Nuclcar Data for Science and Technology. 2. 639-641 (1994)

Takaaki Ohsawa：“小锕系元素裂变中子谱的评估”国际核子数据科学技术会议论文集。