0.1-20MeV能区n+～（31）P的全套中子数据理论计算及评价

【作者】 李江挺；

【导师】 孙秀泉；

【作者基本信息】 西北大学 ， 光学， 2005， 硕士

【摘要】 ³¹P是磷元素唯一稳定的同位素。美国的ENDF/B-6库和日本的JENDL3.3库都有³¹P的一些评价数据。ENDF/B-6和JENDL3.3分别在1977年和2001年对³¹P进行了评价,但是目前仍然存在一些地方需要改进。为了改进³¹P的全套中子核数据,据根据最新的和更加可靠的实验数据,对0.1-20MeV能区进行了理论模型计算。 n+³¹P的全套中子数据模型计算是根据球光学模型理论,扭曲波波恩近似,统一的Hauser-Feshbach激子模型等理论对中子入射能量从0.1Mev到20MeV的全套中子数据进行模型计算。通过查询EXFOR库和CINDA索引库获取最新的实验数据。充分考虑了实验数据及理论参数的系统性,尤其对实验数据少或实验数据偏差大的数据进行了研究和取舍。根据最新的和更加可靠的实验数据,通过光学势调参程序APOM94,给出了一套能再现实验数据的光学势参数。核反应的直接部分用扭曲波波恩近似的DWUCK4程序进行计算,用UNF程序进行光参及相关参数调整和全套中子核数据的理论计算,计算过程中需要根据收集到的实验数据进行参数的调节,得出可靠的全套中子数据,包括各个反应道的截面,角分布,双微分截面等。 计算中用到APOM94、DWUCK4、UNF三个主要程序,及其他辅助程序。模型计算结果与实验值符合的很好,各个反应道截面,角分布数据给出了与ENDF/B-6和JENDL3.3比较的图。与ENDF/B-6和JENDL3.3相比,UNF程序的n+³¹p模型计算有许多改进,结果更合理可信。全套n+³¹p的数据以ENDF/B格式给出。更多还原

【Abstract】 ³¹P is the only stable isotope of phosphorus. The evaluation of neutron data of ³¹P in the energy range from 0.1 to 20MeV was carried out. According to the experimental data and theoretic program UNF code, the neutron data were re-evaluated, compared with the data of ENDF/B-6 and JENDL3.3. The neutron optical potential parameters for ³¹P were obtained respectively, according to the available neutron experimental data, with the code APOM94. The DWUCK4 code was used to investigate the cross section for neutron direct inelastic scattering.The experimental data of ³¹P from neutron-induced reaction with energy lower than 20MeV were collected from EXFOR and current publications. From fitting the total, non-elastic scattering cross section and elastic angular distributions, the parameters of neutron optical potential were calculated by the code APOM94. The parameters of the neutron optical potential is also employed as input data for the DWUCK4 code in order to get the cross section for neutron direct inelastic scattering. In UNF code the spherical optical potential is employed to calculate total cross section, shape elastic scattering cross section and its angular distribution, absorption cross section, etc. The UNF code’s parameters of density level, giant dipole resonance, the nuclear level scheme, pair corrections, binding energy were taken from RIPL.The theoretical calculated results of UNF code were in good accordance with the experimental data. Our calculated values are both reasonable in shapes and in physics. The model calculation of n+³¹P improved the neutron reaction data, compared with the data of ENDF/B-6, JENDL3.3. The theoretical results of ³¹P with experimental data are given in B6 format and figures of this paper.更多还原