Ground-state and isomeric-state cross sections for the 138Ce(n,2n)137Ce reaction from its threshold to 20 MeV
Ground-state and isomeric-state cross sections for the 138Ce(n,2n)137Ce reaction from its threshold to 20 MeV
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DOI：
10.1515/ract-2015-2402
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发表时间：
2015-01
影响因子：
1.8
通讯作者：
Junhua Luo;L. An;Li Jiang
中科院分区：
文献类型：
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作者：
Junhua Luo;L. An;Li Jiang
摘要：采用活化技术测定了138Ce(n, 2n)137m、gCe反应在13.5 ~ 14.8 MeV三个中子能量范围内的截面及其同分异构体截面比σm/σg。将CeO2样品和Nb监测箔一起活化，测定反应截面和入射中子通量。单能中子束通过3H(d, n)4He反应形成。用高分辨率γ射线能谱仪测定了反应产物的活性。纯基态截面由亚稳态绝对截面和残余核衰变分析得到。在中子能量从反应阈值到20 MeV的范围内，用核模型程序TALYS-1.6对不同能级密度的截面进行了估计。对结果进行了讨论，并与相应的文献数据进行了比较。
Abstract The cross sections of the 138Ce(n, 2n)137m,gCe reactions and their isomeric cross section ratios σm/σg were measured at three neutron energies between 13.5 and 14.8 MeV using the activation technique. CeO2 samples and Nb monitor foils were activated together to determine the reaction cross section and the incident neutron flux. The monoenergetic neutron beams were formed via the 3H(d, n)4He reaction. The activities induced in the reaction products were measured using high-resolution γ-ray spectroscopy. The pure cross section of the ground-state was derived from the absolute cross section of the metastable state and the residual nuclear decay analysis. The cross sections were also estimated using the nuclear model code, TALYS-1.6 with different level density options at neutron energies varying from the reaction threshold to 20 MeV. Results are discussed and compared with the corresponding literature data.