n D反应的角分布和能量—角分布计算

用TSD程序计算了n D破裂反应出射中子和质子的能量角度分布和弹性散射角分布,其结果用ENDF/B-6格式收入了中国评价核数据第二版,CENDL-2,碎裂反应核数据能量验查误差小于百分之一。TSD程序是储连元及其合作者在三体Faddeev-AGS理论基础上编制而成的。我们用CENDL-2中氘核核数据计算出的n D的弹性散射微分截面和破裂 反应中子和质子的双微分截面与实验较好的符合。     

n D反应的角分布和能量-角分布计算(英文)

用TSD程序计算了n D破裂反应出射中子和质子的能量角度分布和弹性散射角分布,其结果用ENDF/B-6格式收入了中国评价核数据第二版,CENDL-2,碎裂反应核数据能量验查误差小于百分之一。TSD程序是储连元及其合作者在三体Faddeev-AGS理论基础上编制而成的。我们用CENDL-2中氘核核数据计算出的n D的弹性散射微分截面和破裂反应中子和质子的双微分截面与实验较好的符合。     

~(209)Bi中子反应双微分截面的理论计算和分析

根据209Bi与中子反应的总截面、弹性散射截面、去弹性散射截面和弹性散射角分布的实验数据,应用自动调整光学模型势参数程序,得到了一组中子的光学模型势参数;使用这组参数和中子能量在20 MeV以下的核反应理论计算程序并考虑了中子直接非弹性散射的贡献,计算了209Bi与中子反应的所有截面、角分布和能谱,特别是发射中子、质子、氘、氚和α 粒子的双微分截面,γ产生截面和γ产生谱。理论计算结果与实验数据和评价库的结果进行了比较和分析,结果表明:无论是反应截面,还是能谱,现在的结果比ENDF/B-6和JENDL-3评价库中的结果与实验数据符合的更好、更合理。理论计算结果以ENDF/B-6格式推荐并提供使用。     

139La全套中子数据理论计算及评价

利用已有光学模型参数，基于光学模型、扭曲波玻恩近似、统一的Hauser-Feshbach以及角动量宇称相关的激子模型等核反应理论，计算了20 MeV能量范围内，中子与¹³⁹La反应的全套数据，包括反应截面、弹性及非弹性散射角分布、中子及带电粒子出射的能谱及双微分截面等。对模型计算结果进行了评价和统调，加入了共振参数，并将评价结果与实验数据及已有评价数据进行了比对，所有数据均以ENDF-6标准格式输出。     

55 14．2MeV中子诱发^19F双微分截面的理论计算和分析

将适用于1p壳轻核的新的轻核反应理论模型推广到了2s1d壳核-^19F，计算和分析了入射中子能量为14．2Mev时中子诱发^19F反应的总出射中子双微分截面，与实验数据取得了很好的符合。详细分析了不同反应道出射的中子对总出射中子双微分截面的贡献，来自（n,2n）反应道的次级中子在低能端对总出射中子双微分截面的贡献占据主导地位，而^5He崩裂所产生的中子的贡献并不显著。     

中子入射砷核同位素反应全套微观数据的计算与分析

基于光学模型假设和中子与天然砷反应的总截面、去弹截面以及弹性散射角分布的实验数据,获得了一组0.1~20 MeV能量区域内普适于中子与砷核同位素反应的光学势参数。并以该组光学模型参数为前提,利用以光学模型、扭曲波Born近似理论、统一的Hauser-Feshbach统计理论和激子模型等理论为核心的UNF程序,计算了中子与As及其同位素的反应截面、能谱和双微分截面值,并对理论计算值和实验数据进行了比较和分析,理论计算结果与实验数据符合较好,同时给出了无实验数据的区域的理论结果。     

n+232Th核反应光学模型势的计算

利用光学模型、宽度涨落修正的Hauser-Feshbach理论对中子入射232Th核反应进行了研究。以总截面、去弹截面以及弹性散射角分布的实验数据为依据,得到了n+232Th核反应在0.1–20 MeV能量区域的一套中子光学模型势参数,并以此计算了该反应的总截面、弹性散射截面、去弹截面和弹性角分布截面。理论计算结果与实验数据符合较好。     

20MeV以下n＋^6Li反应理论分析和中子数据库建立

轻核的反应截面和次级中子双微分截面数据在核工程设计以及中子辐射屏蔽设计中均有着重要的应用价值。在核数据评价中，轻核双微分截面数据在国际上一直以来都是一个未解决的难题，国际上各大中子评价数据库中都没有很成功的理论模型方法给出既能够保证能量平衡又包含全部出射粒子信息的双微分截面文档。新轻核反应理论采用统一的Hauser-Feshbach和激子模型很好地解决了这些问题。     

中能中子与60Ni反应的理论计算和分析

在中子与⁶⁰Ni反应的总截面、去弹性散射截面和弹性散射角分布的实验数据基础上,获得了入射中子能量0.456~150MeV范围内的一组普适的中子与⁶⁰Ni反应的光学模型势参数。利用光学模型、宽度涨落修正的Hauser-Feshbach理论、预平衡反应的激子模型和核内级联模型的中能核反应计算程序UNF和MEND,计算了中子与⁶⁰Ni反应的所有截面、角分布和能谱,并将理论计算结果与实验数据和评价数据进行了分析比较。     

中子与^181Ta反应的理论计算

本工作运用TALYS程序对中国评价核数据库中重要结构材料核Ta的全套中子数据进行了模型计算。根据中子与^181Ta反应的全截面、弹性散射截面和弹性散射角分布的实验数据，对Koning和Delaroche给出的中子普适光学势参数进行调节，得到一组适用于能量范围在0．1～30MeV之间、中子与^181Ta反应的光学模型势参数。     

Ep≤200 MeV能区p+58Ni反应的计算与分析

以现有质子诱发⁵⁸Ni的各种核反应截面、能谱、双微分截面、弹性散射角分布等实验数据为基础，利用自行研制的大型核模型计算程序MEND计算质子能量在200MeV能区内⁵⁸Ni(p,x)反应的截面、能谱、角分布和n、p、α、d、t、³He6种出射轻粒子的双微分截面。MEND程序的理论框架基于球形光学模型、核子的核内级联发射模型、以激子模型为基础的预平衡发射理论、蒸发模型和带宽度涨落修正的Hauser Feshbach统计理论。光学模型中的势参数由APMN程序通过符合p+⁵⁸Ni反应的去弹截面和弹性散射角分布获得。出射粒子的双微分截面则利用MEND程序输出的能谱再通过Kalbach系统学公式计算。将计算结果与实验数据及ENDF/B6评价库进行了比较，计算结果与实验数据基本一致，与ENDF/B6相比，增加了³He的计算，且将能区上推至200MeV。      

Calculation and analysis of proton-induced reactions on Ni at incident energies from threshold to 200 MeV

Proton-induced reactions on ⁵⁸Ni have been studied in the energy range from threshold to 200 MeV. Based on experimental data of elastic scattering angular distributions and nonelastic cross section, an optimal set of proton optical potential parameters for ⁵⁸Ni has been obtained. All cross sections, elastic and inelastic scattering angular distributions, energy spectra and especially double differential cross sections for neutrons, protons, deuterons, tritons, helium particles and alpha particles emission have been calculated, using nuclear models theory. Theoretical calculations have been compared with existing experimental data, in most cases, the calculated results are in good agreement with the experimental data.     

Evaluation of Neutron- and Proton-induced Nuclear Data on 27Al up to 2 GeV

We have evaluated neutron and proton nuclear data of ²⁷ Al for energies up to 2 GeV. The best set of optical model parameters were obtained from 20MeV for neutrons and from reaction threshold for protons up to 250 MeV with the phenomenological non-relativistic potential forms incorporating effects of the dispersion relationship and results of the Dirac phenomenology. The transmission coefficients for neutrons and protons derived from the optical models were fed into the GNASH code system to calculate angle-energy correlated emission spectra for light ejectiles and gamma rays. For energies between 250 MeV and 2 GeV, the total, reaction and elastic scattering cross sections were evaluated by an empirical fit and recent systematics. Emitted nucleon and pion spectra were estimated by use of QMD+SDM (Quantum Molecular Dynamics+Statistical Decay Model).     

Calculation and evaluations for n+Cu reactions

All cross sections of neutron induced reactions, angular distributions, energy spectra and double differential cross sections are consistently calculated and analyzed for n+^63,65,nat.Cu reactions at incident neutron energies below 200 MeV based on the nuclear theoretical models. The optical model, preequilibrium and equilibrium reaction theories, the distorted wave Born approximation theory are used. Theoretical calculated results are compared with existing experimental data and the evaluated results in ENDF/B-VII and JENDL-3 libraries. The optical model potential parameters are obtained according to the experimental data of total, nonelastic scattering cross sections and elastic scattering angular distributions.     

利用瞬发γ射线法测量209Bi的中子非弹性散射截面

在铅铋快堆、空间堆等先进反应堆中,铋作为冷却剂和慢化剂材料被大量使用,其中子核反应截面,尤其是中子非弹性散射截面的准确性对这些核装置的安全性和经济性等具有重要的影响。基于中国原子能科学研究院HI 13串列加速器瞬发γ射线实验平台,通过瞬发γ射线法测量了209Bi在90、105和120 MeV 3个能点的中子非弹性散射截面。在相对于中子束30°、70°、110°和150°方向放置4个Clover探测器测量中子与样品相互作用产生的γ射线。实验采用相对测量,通过测量中子与48Ti发生非弹性散射发射的9835 keV γ射线的产生截面来确定209Bi的截面。209Bi金属样品的尺寸为50 mm×4 mm,参考样品为1块50 mm×1 mm的天然钛金属样品。将实验测量结果与已发表的实验数据、ENDF/B Ⅷ.0、JEFF 33、JENDL 40、ROSFOND 2010和CENDL 31等评价库数据以及Talys 195程序默认参数的计算结果进行对比,发现趋势一致,90、105 MeV能点的测量结果与Talys 195程序的计算结果符合得更好,120 MeV能点的测量结果与ROSFOND 2010评价库数据符合得更好。     

中子与58,60Ni反应的理论计算

根据中子与天然Ni及其同位素反应的总截面、去弹截面和弹性散射角分布的实验数据，得到中子的光学模型势参量。应用得到的光学模型势参量，根据光学模型、统一的Hauser-Feshbach和激子模型理论以及扭曲波玻恩近似理论，系统计算和分析了中子与^58,60Ni反应的非弹散射角分布和双微分截面，理论结果与实验很好地一致。     

Energy Loss Distribution of Recoil Protons in Stilbene Scintillator

Formulas are derived for calculating the energy loss distribution of recoil protons in a cylindrical organic scintillator with a broad beam of fast neutrons in the energy range 1 to 15 MeV perpendicularly incident on its base. The assumptions are: (1) the scintillator is composed solely of hydrogen and carbon; (2) only elastic scattering from hydrogen and carbon is considered in relation to the interaction of fast neutrons with the scintillator; (3) single and double scattering alone are considered; (4) wall effect is neglected for recoil protons produced in the second collisions; (5) the radius and the thickness of the scintillator are greater than the range of recoil protons of the highest energy.

As an example, the calculated results are shown for stilbene crystals of 1″ dia. and 1/8″ to 1″ thick. In scintillators of thicknesses below 1/4″, and for incident fast neutrons in the energy range from 3 to 15 MeV, the contribution of double scattering to the energy loss distribution of recoil protons is below about 10% of that of single scattering, while wall effect is quite significant, in particular, for incident neutrons of high energy.     

22 MeV polarized proton scattering from 40Ca and effective NN interactions

Analyzing powers and differential cross sections have been measured for elastic scattering of 22 MeV polarized protons from ^40Ca ,^16O and ^12C ,and differential cross sections for inelastic scattering of 22MeV protons from 3^-(3.736 MeV)and 5^-(4.491 MeV) states of ^40Ca have also been measured .The experimental data for polarized proton elastic scattering have been analyzed with a phenomenological optical potential parameters,the experimental data and theoretical values are in good agreement .In the theoretical frome of microscopic single scattering model,transition densities extracted from electron inelastic scattering and M3Y and Halderson‘s effective interactions have been utilized to analyze the experimental data of 22 MeV proton inelastic scattering from ^40Ca.Overall,it seems that Halderson‘s effective interaction can better describe the experimental data than M3Y although the degree of agreement between experimental and theoretical values needs to be improved.     

Theoretical calculation and analysis of the p+Co reaction

All cross sections, elastic and inelastic scattering angular distributions, energy spectra, and double differential cross sections of neutron, proton, deuteron, triton, helium and alpha particle emission for the p+⁵⁹Co reaction have been calculated and analyzed at incident energies from threshold to 200 MeV. The optical model, the intra-nuclear cascade model, direct, pre-equilibrium and equilibrium reaction theories are used. It is found that the theoretical calculated results are in good agreement with experimental data.