The structural effect is believed to have no influence on the decay properties of medium and heavy-mass nuclei at excitation energies above the pairing gap.These properties can be described by statistical properties u...The structural effect is believed to have no influence on the decay properties of medium and heavy-mass nuclei at excitation energies above the pairing gap.These properties can be described by statistical properties using so-called photon strength functions for different multipolarities,and directly related to the photoabsorption cross-section(σabs).σabs is dominated by the electric giant dipole resonance at y energy εγ≤40 MeV.In this study,we construct two kinds of systematic giant dipole resonance parameters by fitting the experimental photoabsorption crosssections.One is based on the microscopic relativistic quasiparticle random phase approximation approach,whereas the other is estimated by the phenomenological models within the Lorentzian representation.Both of them are demonstrated of efficiently describe the experimental photoabsorption cross-sections available for medium to heavymass nuclei,and they can obtain more reliable predictions for the unknown nuclear system.展开更多
考虑特征γ射线分支比、衰变常数和标准截面等修正,对带电粒子引起的核反应^(186)W(d,p)^(187)W,^(186)W(d,2n)^(186)Re,^(nat)Fe(p,x)^(56)Co和^(nat)Ti(a,x)^(51)Cr的激发函数进行了研究。全面收集了这些反应激发函数的实验测量数据,...考虑特征γ射线分支比、衰变常数和标准截面等修正,对带电粒子引起的核反应^(186)W(d,p)^(187)W,^(186)W(d,2n)^(186)Re,^(nat)Fe(p,x)^(56)Co和^(nat)Ti(a,x)^(51)Cr的激发函数进行了研究。全面收集了这些反应激发函数的实验测量数据,对这些实验数据进行了分析处理,应用数学方法对分析处理后的实验数据进行了拟合。经过评价,给出了50 Me V以下^(186)W(d,p)^(187)W,^(186)W(d,2n)^(186)Re,^(nat)Fe(p,x)^(56)Co和^(nat)Ti(a,x)^(51)Cr反应激发函数的推荐值。展开更多
To satisfy the requirements of nuclear reaction cross sections in nuclear engineering applications and nuclear physics studies,the Neutron Activation Cross Section Data Library has been established.818 target nuclei i...To satisfy the requirements of nuclear reaction cross sections in nuclear engineering applications and nuclear physics studies,the Neutron Activation Cross Section Data Library has been established.818 target nuclei including unstable target or isomeric target nuclei are considered in this library.The induced neutron energy range region is between 10^(-5)eV and 20 MeV.The standard ENDF-6 format is adopted,including general information,reaction cross sections,multiplicities,and so on.The recommended reaction cross sections were obtained using UNF code system and FDRR nuclear model codes or systematic analysis based on available experimental data.展开更多
A new value for the emission probability of 137.144 keV γ-rays from 186gRe decay is recommended to be （9.47±0.03）/%. Using this value the measured cross sections for 187Re（n,2n）186mRe and 187Re（n,2n）186gRe...A new value for the emission probability of 137.144 keV γ-rays from 186gRe decay is recommended to be （9.47±0.03）/%. Using this value the measured cross sections for 187Re（n,2n）186mRe and 187Re（n,2n）186gRe reactions around 14 MeV are analyzed, and the cross section for187Ke（n,2n）186m＋gRe reaction at 14.g MeV is （2213=k116） mb. The UNF code was adopted to calculate the cross sections for the 187Re（n,2n）186m＋gRe reaction below 20 MeV, fitting to the value （2213±116） mb at 14.8 MeV using a set of optimum neutron optical potential parameters which were obtained based on the relevant experimental data of rhenium. The isomeric cross section ratio for the 187Re（n,2n）186m,gRe reaction was analyzed using the V-H method based on nuclear statistical theory. Combining these calculated results, the excitation functions for the 187Re（n,2n）lS6mRe and 187Re（n,2n）186gRe reactions were obtained. The obtained results are in good agreement with the available experimental data.展开更多
基金Supported by the IAEA Coordinated Research Project F41032(20466)the National Natural Science Foundation of China(U1432247,11775013,11305270,11465005,U1630143)+1 种基金the Science Challenge Project(TZ2018001)the Key Laboratory fund key projects(6142A080201)
文摘The structural effect is believed to have no influence on the decay properties of medium and heavy-mass nuclei at excitation energies above the pairing gap.These properties can be described by statistical properties using so-called photon strength functions for different multipolarities,and directly related to the photoabsorption cross-section(σabs).σabs is dominated by the electric giant dipole resonance at y energy εγ≤40 MeV.In this study,we construct two kinds of systematic giant dipole resonance parameters by fitting the experimental photoabsorption crosssections.One is based on the microscopic relativistic quasiparticle random phase approximation approach,whereas the other is estimated by the phenomenological models within the Lorentzian representation.Both of them are demonstrated of efficiently describe the experimental photoabsorption cross-sections available for medium to heavymass nuclei,and they can obtain more reliable predictions for the unknown nuclear system.
文摘考虑特征γ射线分支比、衰变常数和标准截面等修正,对带电粒子引起的核反应^(186)W(d,p)^(187)W,^(186)W(d,2n)^(186)Re,^(nat)Fe(p,x)^(56)Co和^(nat)Ti(a,x)^(51)Cr的激发函数进行了研究。全面收集了这些反应激发函数的实验测量数据,对这些实验数据进行了分析处理,应用数学方法对分析处理后的实验数据进行了拟合。经过评价,给出了50 Me V以下^(186)W(d,p)^(187)W,^(186)W(d,2n)^(186)Re,^(nat)Fe(p,x)^(56)Co和^(nat)Ti(a,x)^(51)Cr反应激发函数的推荐值。
基金supported by the National Natural Science Foundation of China (Grant Nos. 11934004 and U1832201)the Science Challenge Project (Grant No. TZ2016005)the CAEP Foundation (Grant No. CX2019022)
文摘To satisfy the requirements of nuclear reaction cross sections in nuclear engineering applications and nuclear physics studies,the Neutron Activation Cross Section Data Library has been established.818 target nuclei including unstable target or isomeric target nuclei are considered in this library.The induced neutron energy range region is between 10^(-5)eV and 20 MeV.The standard ENDF-6 format is adopted,including general information,reaction cross sections,multiplicities,and so on.The recommended reaction cross sections were obtained using UNF code system and FDRR nuclear model codes or systematic analysis based on available experimental data.
文摘A new value for the emission probability of 137.144 keV γ-rays from 186gRe decay is recommended to be （9.47±0.03）/%. Using this value the measured cross sections for 187Re（n,2n）186mRe and 187Re（n,2n）186gRe reactions around 14 MeV are analyzed, and the cross section for187Ke（n,2n）186m＋gRe reaction at 14.g MeV is （2213=k116） mb. The UNF code was adopted to calculate the cross sections for the 187Re（n,2n）186m＋gRe reaction below 20 MeV, fitting to the value （2213±116） mb at 14.8 MeV using a set of optimum neutron optical potential parameters which were obtained based on the relevant experimental data of rhenium. The isomeric cross section ratio for the 187Re（n,2n）186m,gRe reaction was analyzed using the V-H method based on nuclear statistical theory. Combining these calculated results, the excitation functions for the 187Re（n,2n）lS6mRe and 187Re（n,2n）186gRe reactions were obtained. The obtained results are in good agreement with the available experimental data.
