Nuclear uncertainties in the s-process simulation  

作　　者：ZHANG YouJin CHEN YongShou GUO JianYou HOU SuQing LI ZhiHong SHI JianRong 

机构地区：[1]School of Physics and Material Science,Anhui University [2]China Institute of Atomic Energy [3]Institute of Modern Physics,Chinese Academy of Sciences [4]National Astronomical Observatories,Chinese Academy of Sciences

出　　处：《Science China(Physics,Mechanics & Astronomy)》2013年第5期859-865,共7页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 11021504, 11175258, 11275068 and 11175001);the Major State Basic Research Development Program of China (Grant No.2013CB834406)

摘　　要：The heavy elements in the Universe are formed during the s- and r-processes mainly in AGB stars and supernovae, respectively. Simulation of s- and r-nucleosynthesis critically depends on the neutron capture and weak decay rates for all the nuclei on the reaction chain. The present work analyzes systematically the neutron capture rates (cross sections) for the s-process nuclei, including ～3000 rates on ～200 nuclei. The network calculations for the constant temperature s-process have been performed using the different data sets selected as the nuclear inputs to investigate the uncertainties in the predicted s-abundances. We show that the available cross sections of neutron capture on many s-process nuclei still carry large uncertainties, which lead to low accuracy in the determination of s-process isotope abundances. We analyze the neutron capture cross section data for the same unique isobar nucleus accorded by year from previous work. Such an analysis indicates that the s-process has been studied for more than fifty years and there exist two research stages around 1976 and 2002, respectively. The needs and opportunities for future experiments and theoretical tools are highlighted to remove the existing shortcomings in the neutron capture rates.The heavy elements in the Universe are formed during the s- and r-processes mainly in AGB stars and supernovae, respectively. Simulation of s- and r-nucleosynthesis critically depends on the neutron capture and weak decay rates for all the nuclei on the reaction chain. The present work analyzes systematically the neutron capture rates （cross sections） for the s-process nuclei, includ- ing -3000 rates on ~200 nuclei. The network calculations for the constant temperature s-process have been performed using the different data sets selected as the nuclear inputs to investigate the uncertainties in the predicted s-abundances. We show that the available cross sections of neutron capture on many s-process nuclei still carry large uncertainties, which lead to low accuracy in the determination of s-process isotope abundances. We analyze the neutron capture cross section data for the same unique isobar nucleus accorded by year from previous work. Such an analysis indicates that the s-process has been studied for more than fifty years and there exist two research stages around 1976 and 2002, respectively. The needs and opportunities for future experiments and theoretical tools are highlighted to remove the existing shortcomings in the neutron capture rates.

关 键 词：NUCLEOSYNTHESIS neutron capture reaction S-PROCESS nuclear reaction network 

分 类 号：O571[理学—粒子物理与原子核物理]