Fission fragments yields and average total kinetic energy are fundamental nuclear data for nuclear energy applications and the study of nuclear devices.Certain fission products,such as ^(95)Zr,^(99)Mo,^(140)Ba,^(144)C...Fission fragments yields and average total kinetic energy are fundamental nuclear data for nuclear energy applications and the study of nuclear devices.Certain fission products,such as ^(95)Zr,^(99)Mo,^(140)Ba,^(144)Ce,and ^(147)Nd,serve as burnup monitors,assessing the number of fissions induced by neutrons on ^(235)U.However,current experimental data for these fission products worldwide are inconsistent,introducing significant uncertainty into related scientific research.In this study,we employed the Potential-driving Model to calculate the independent yields of ^(235)U and evaluate its advantages in such calculations.Additionally,we investigated the energy dependence of independent yields to select important products.Furthermore,we calculated the cumulative yields of ^(95)Zr,^(99)Mo,^(140)Ba,^(144)Ce,and ^(147)Nd,and compared them with existing literature data to explore the energy dependence of fission products for ^(235)U.Given the lack of fission product yield data above 14.8 MeV,we extended our calculated incident neutron energy to 20 MeV,aiming to support future scientific research.The Geant4 physical model does not consider the influence of incident neutron energy on the average total kinetic energy of fission fragments;thus,we introduced the excitation function of the total kinetic energy of fission fragments recommended by Madland et al.,which effectively describes the experimental data of the average total kinetic energy of fragments formed in ^(235)U fission.In this paper,we comprehensively discuss the energy dependence of fission product yields and average total kinetic energy.展开更多
Pre-neutron fragment mass yields in the vicinity of the thermal neutron energy are highly important for applications because of the larger fission cross sections of the^(235)U(n,f)and^(239)Pu(n,f)reactions.In this pap...Pre-neutron fragment mass yields in the vicinity of the thermal neutron energy are highly important for applications because of the larger fission cross sections of the^(235)U(n,f)and^(239)Pu(n,f)reactions.In this paper,preneutron fragment mass yields at incident energies from thermal up to 20 MeV are systematically studied using an empirical fission potential(EFP)model,the potential parameters of which are obtained from the measured data.The energy dependences of the peaks and valleys of the pre-neutron fragment mass yields are described by exponential and linear functions for the^(235)U(n,f)and^(239)Pu(n,f)reactions,respectively.The energy dependences of the evaporation neutrons,which play a crucial role in the reasonable description of pre-neutron fragment mass yields,are also obtained from the fission cross sections.The pre-neutron fragment mass yields in this study are not only consistent with the results of previous studies in regions of several Me Vs but also agree well with existing measured data at incident energies from thermal up to 20 MeV.The results show that the feasibility of this EFP model is verified in this extended energy region.展开更多
基金Supported by the National Natural Science Foundation of China(12075105)the NSFC-Nuclear Technology Innovation Joint Fund(U2167203)+1 种基金the Major Science and Technology Projects of Gansu Province(22ZD6GB020)the Fundamental Research Funds for the Central Universities of China(lzujbky-2022-ey14,Izujbky-2022-kb07)。
文摘Fission fragments yields and average total kinetic energy are fundamental nuclear data for nuclear energy applications and the study of nuclear devices.Certain fission products,such as ^(95)Zr,^(99)Mo,^(140)Ba,^(144)Ce,and ^(147)Nd,serve as burnup monitors,assessing the number of fissions induced by neutrons on ^(235)U.However,current experimental data for these fission products worldwide are inconsistent,introducing significant uncertainty into related scientific research.In this study,we employed the Potential-driving Model to calculate the independent yields of ^(235)U and evaluate its advantages in such calculations.Additionally,we investigated the energy dependence of independent yields to select important products.Furthermore,we calculated the cumulative yields of ^(95)Zr,^(99)Mo,^(140)Ba,^(144)Ce,and ^(147)Nd,and compared them with existing literature data to explore the energy dependence of fission products for ^(235)U.Given the lack of fission product yield data above 14.8 MeV,we extended our calculated incident neutron energy to 20 MeV,aiming to support future scientific research.The Geant4 physical model does not consider the influence of incident neutron energy on the average total kinetic energy of fission fragments;thus,we introduced the excitation function of the total kinetic energy of fission fragments recommended by Madland et al.,which effectively describes the experimental data of the average total kinetic energy of fragments formed in ^(235)U fission.In this paper,we comprehensively discuss the energy dependence of fission product yields and average total kinetic energy.
基金Supported by the National Natural Science Foundation of China(12065003)the Natural Science Foundation of Guangxi(2019GXNSFDA185011)+2 种基金the Key Laboratory of Neutron Physics China Academy of Engineering Physics(2018BA03)the Scientific Research and Technology Development Project of Guilin(20210104-2)the Central Government Guides Local Scientic and Technological Development Funds of China(Guike ZY22096024)。
文摘Pre-neutron fragment mass yields in the vicinity of the thermal neutron energy are highly important for applications because of the larger fission cross sections of the^(235)U(n,f)and^(239)Pu(n,f)reactions.In this paper,preneutron fragment mass yields at incident energies from thermal up to 20 MeV are systematically studied using an empirical fission potential(EFP)model,the potential parameters of which are obtained from the measured data.The energy dependences of the peaks and valleys of the pre-neutron fragment mass yields are described by exponential and linear functions for the^(235)U(n,f)and^(239)Pu(n,f)reactions,respectively.The energy dependences of the evaporation neutrons,which play a crucial role in the reasonable description of pre-neutron fragment mass yields,are also obtained from the fission cross sections.The pre-neutron fragment mass yields in this study are not only consistent with the results of previous studies in regions of several Me Vs but also agree well with existing measured data at incident energies from thermal up to 20 MeV.The results show that the feasibility of this EFP model is verified in this extended energy region.
