裂变谱中子诱发^(235)U裂变产物核Xe的产额评价  

Fission Yields Evaluation for Xe Isotopes from nF+^(235)U

作　　者：曹超维 李畅 舒能川[1] 刘玲[2] 宿阳 陈永静 刘丽乐[1] CAO Chaowei;LI Chang;SHU Nengchuan;LIU Ling;SU Yang;CHEN Yongjing;LIU Lile(China Institute of Atomic Energy,Beijing 102413,China;Shenyang Normal University,Shenyang 110000,China)

机构地区：[1]中国原子能科学研究院,北京102413 [2]沈阳师范大学,辽宁沈阳110000

出　　处：《原子能科学技术》2024年第11期2269-2277,共9页Atomic Energy Science and Technology

基　　金：国家财政部稳定支持基础科研计划。

摘　　要：裂变产额是核工程应用和核物理科研中最重要的基础核数据之一,特别是裂变气体产物核,对核装置的设计、运行有不可忽视的影响,因此对中子诱发裂变的气体产物核裂变产额进行评价,得到可靠的产额对核工程的应用和基础研究核技术的发展具有重要意义。本工作针对裂变谱能区中子诱发^(235)U裂变的Xe气体产物核,在EXFOR实验数据基础上,采用基于Zp模型的裂变统一评价方法,对其所在质量链的裂变产物的独立产额、累积产额进行了统一拟合评价,并与现有评价库中Xe的产额进行了比较,对存在分歧的产额进行了进一步分析,给出了合理的解释。与传统方法比较,统一评价方法给出的产额具有更好的可靠性和合理性,同时解决了传统方法独立产额、累积产额不自洽的问题。Fission yield is one of important basic nuclear data in nuclear engineering applications and nuclear physics research,especially for the fission gas products which have non-negligible impact on the design and operation of nuclear devices.Therefore,evaluating and providing a set of new yields for the gas products with more liability is of great significance to the nuclear application and basic research.The traditional fission yield evaluation method usually evaluate the specific fission yield(such as independent fission yield)of a certain nucleus separately,did not consider the physical relations between the products on the same decay chain,even the other chain which may have contribution through beta-n decay.And this may result to the inconsistency among yields of these products.For an example,131Xe is contributed from the nF+^(235)U fission and precursor’s(131I and 131Xem)decay,so its cumulative yield should be the summation of the independent yields of and 131Xe,131Xem and the cumulative yield of 131I.It can not satisfy the needs from the engineering applications.In order to solve the inconsistency problem,a unified evaluation method was developed based upon the Zp model,which can describe the independent and cumulative fission yields simultaneously for the products on the same mass chain A,wherein the decay branches are the connections between the two types of the yields.There are 4 parameters in the model,which are obtained by fitting to experimental cumulative and independent fission fields,and consequently the fission yield could be reproduced.In this work,the model was applied to evaluation the yields of Xe of ^(235)U fission induced by fission neutron,where the experimental data were collected from EXFOR library.Comparisons were performed between the present work and the data from ENDF/B-Ⅷ.0 and JEEF-3.3.For 131Xe,the present value is little higher than that of ENDF/B-Ⅷ.0 and lower than that of the JEFF-3.3 consider the contribution of the precursor 131I.For 135Xe,the present value is lower than the

关 键 词：裂变产额 Zp模型 ^(235)U中子诱发裂变 XE 

分 类 号：TL11[核科学技术—核能科学] O571[理学—粒子物理与原子核物理]