In loosely coupled or large-scale problems with high dominance ratios,slow fission source convergence can take extremely long time,reducing Monte Carlo(MC)criticality calculation efficiency.Although various accelerati...In loosely coupled or large-scale problems with high dominance ratios,slow fission source convergence can take extremely long time,reducing Monte Carlo(MC)criticality calculation efficiency.Although various acceleration methods have been developed,some methods cannot reduce convergence times,whereas others have been limited to specific problem geometries.In this study,a new fission source convergence acceleration(FSCA)method,the forced propagation(FP)method,has been proposed,which forces the fission source to propagate and accelerate fission source convergence.Additionally,some stabilization techniques have been designed to render the method more practical.The resulting stabilized method was then successfully implemented in the MC transport code,and its feasibility and effectiveness were tested using the modified OECD/NEA,one-dimensional slab benchmark,and the Hoogenboom full-core problem.The comparison results showed that the FP method was able to achieve efficient FSCA.展开更多
Near 50 years history of the development of radioisotope neutron sources in China is briefly reviewed.The structure design,preparing technology and production status of routine neutron sources including 210Po-Be sourc...Near 50 years history of the development of radioisotope neutron sources in China is briefly reviewed.The structure design,preparing technology and production status of routine neutron sources including 210Po-Be sources,210Po mock fission sources,241Am-Be sources,238Pu-Be sources,252Cf spontaneous fission sources and other special-shape neutron sources are summarized.In addition,the prospects of development on radioisotope neutron source in China are predicted from the needs of nuclear power construction,oil well-logging,neutron moisture gauge and neutron brachytherapy.展开更多
基金supported by the National Natural Science Foundation of China(Nos.11775126,11545013,11605101)the Young Elite Scientists Sponsorship Program by CAST(No.2016QNRC001)+1 种基金Science Challenge Project by MIIT of China(No.TZ2018001)Tsinghua University,Initiative Scientific Research Program。
文摘In loosely coupled or large-scale problems with high dominance ratios,slow fission source convergence can take extremely long time,reducing Monte Carlo(MC)criticality calculation efficiency.Although various acceleration methods have been developed,some methods cannot reduce convergence times,whereas others have been limited to specific problem geometries.In this study,a new fission source convergence acceleration(FSCA)method,the forced propagation(FP)method,has been proposed,which forces the fission source to propagate and accelerate fission source convergence.Additionally,some stabilization techniques have been designed to render the method more practical.The resulting stabilized method was then successfully implemented in the MC transport code,and its feasibility and effectiveness were tested using the modified OECD/NEA,one-dimensional slab benchmark,and the Hoogenboom full-core problem.The comparison results showed that the FP method was able to achieve efficient FSCA.
文摘Near 50 years history of the development of radioisotope neutron sources in China is briefly reviewed.The structure design,preparing technology and production status of routine neutron sources including 210Po-Be sources,210Po mock fission sources,241Am-Be sources,238Pu-Be sources,252Cf spontaneous fission sources and other special-shape neutron sources are summarized.In addition,the prospects of development on radioisotope neutron source in China are predicted from the needs of nuclear power construction,oil well-logging,neutron moisture gauge and neutron brachytherapy.
