Knowledge of actinides(n,f) fission process induced by neutron is of importance in the field of nuclear power and nuclear engineering,especially for reactor applications.In this work,fission characteristics of^(238)U(...Knowledge of actinides(n,f) fission process induced by neutron is of importance in the field of nuclear power and nuclear engineering,especially for reactor applications.In this work,fission characteristics of^(238)U(n,f) reaction induced by D-T neutron source were simulated with Geant4 code from multiple perspectives,including the fission production yields,total nubar,kinetic energy distribution,fission neutron spectrum and cumulative γ-ray spectrum of the fission products.The simulation results agree well with the experimental nuclear reaction data(EXFOR) and evaluated nuclear data(ENDF).Mainly,this work was to examine the rationality of the parametric nuclear fission model in Geant4 and to direct our future experimental measurements for the cumulative fission yields of ^(238)U(n,f) reaction.展开更多
The reaction cross-sections of^(238)U(n,γ)^(239)U have been experimentally determined at neutron energies of6.117±0.119 MeV,4.626±0.086 MeV,and 3.622±0.348 MeV employing the relative activation approac...The reaction cross-sections of^(238)U(n,γ)^(239)U have been experimentally determined at neutron energies of6.117±0.119 MeV,4.626±0.086 MeV,and 3.622±0.348 MeV employing the relative activation approach along with the off-line γ-ray spectroscopy method.The D(d,n)3He reaction was utilized to obtain monoenergetic neutrons of the required energy,and the^(197)Au(n,γ)^(198)Au reaction cross-sections were adopted as the referential standard to ascertain the neutron capture cross-sections of^(238)U.Furthermore,the effects of low-energy scattered neutrons,neutron fluence fluctuations,counting of geometric corrections when measuring γ-rays,and neutron and γ-ray self-absorption caused by the sample thickness have been considered and revised in the present work.For a comparison with experimental results,the cross-sections of the^(238)U(n,γ)^(239)U reaction were calculated theoretically with the original parametric TALYS-1.9 program.The experimental measurements were in contrast to previous experimental re sults and the evaluation data available for ROSFOND-2010,CENDL-3.2 and ENDF/B-VIII.0.展开更多
In this work, Rotation model and rotation vibration coupled channel optical model (CCOM) were first used to carry out systematic calculation of neutron direct inelastic scattering cross section (DISCS) for the reacti...In this work, Rotation model and rotation vibration coupled channel optical model (CCOM) were first used to carry out systematic calculation of neutron direct inelastic scattering cross section (DISCS) for the reaction 238 U (n,n′) with an incident energy from 0 01 MeV to 20 0 MeV . The number of coupled energy levels involved in this calculation increased to eight at the first time, namely 0 +, 2 +, 4 +, 6 +, 8 + in the ground rotation band of 238 U and 1 -, 3 -, 5 - in the octupole vibration band with K=0 -. Some physical problems, such as how to get the optical model parameters of deformed nuclei and phonon amplitudes, are discussed.展开更多
基金Major State Basic Research Development Programs for Basic Research of China(2007CB209903,2008CB717803)Research Fund for Doctoral Programof Higher Education of China(200610001023)National Found for Fostering Talents of Basic Science of China(J0630311)~~
基金supported by the National Natural Science Foundation of China(No.21327801)
文摘Knowledge of actinides(n,f) fission process induced by neutron is of importance in the field of nuclear power and nuclear engineering,especially for reactor applications.In this work,fission characteristics of^(238)U(n,f) reaction induced by D-T neutron source were simulated with Geant4 code from multiple perspectives,including the fission production yields,total nubar,kinetic energy distribution,fission neutron spectrum and cumulative γ-ray spectrum of the fission products.The simulation results agree well with the experimental nuclear reaction data(EXFOR) and evaluated nuclear data(ENDF).Mainly,this work was to examine the rationality of the parametric nuclear fission model in Geant4 and to direct our future experimental measurements for the cumulative fission yields of ^(238)U(n,f) reaction.
基金Supported by the Key Laboratory of Nuclear Data foundation (6142A08200104)。
文摘The reaction cross-sections of^(238)U(n,γ)^(239)U have been experimentally determined at neutron energies of6.117±0.119 MeV,4.626±0.086 MeV,and 3.622±0.348 MeV employing the relative activation approach along with the off-line γ-ray spectroscopy method.The D(d,n)3He reaction was utilized to obtain monoenergetic neutrons of the required energy,and the^(197)Au(n,γ)^(198)Au reaction cross-sections were adopted as the referential standard to ascertain the neutron capture cross-sections of^(238)U.Furthermore,the effects of low-energy scattered neutrons,neutron fluence fluctuations,counting of geometric corrections when measuring γ-rays,and neutron and γ-ray self-absorption caused by the sample thickness have been considered and revised in the present work.For a comparison with experimental results,the cross-sections of the^(238)U(n,γ)^(239)U reaction were calculated theoretically with the original parametric TALYS-1.9 program.The experimental measurements were in contrast to previous experimental re sults and the evaluation data available for ROSFOND-2010,CENDL-3.2 and ENDF/B-VIII.0.
文摘In this work, Rotation model and rotation vibration coupled channel optical model (CCOM) were first used to carry out systematic calculation of neutron direct inelastic scattering cross section (DISCS) for the reaction 238 U (n,n′) with an incident energy from 0 01 MeV to 20 0 MeV . The number of coupled energy levels involved in this calculation increased to eight at the first time, namely 0 +, 2 +, 4 +, 6 +, 8 + in the ground rotation band of 238 U and 1 -, 3 -, 5 - in the octupole vibration band with K=0 -. Some physical problems, such as how to get the optical model parameters of deformed nuclei and phonon amplitudes, are discussed.
