The (n,γ) reaction cross-section of rare earth stable fission products, such as ¹⁵²Sm, ¹⁵⁴Sm and ¹⁵⁰Nd, in the neutron energy range of 0.8 to 2 MeV, obtained from ⁷Li(p,n)⁷Be reaction, was measured by neutron activation followed by off-line gamma-ray spectrometry. Natural strontium (^natSr) has been established as a fast neutron flux monitor in this work, by measuring the ^natSr(n,γ+n,n′)⁸⁷Sr^m reaction cross-section using ¹²⁷I(n,γ)¹²⁸I as monitor reaction. The cross-section for ⁸⁶Sr(n,γ)⁸⁷Sr^m has been determined for the first time to the best of our knowledge. The excellent decay properties of ⁸⁷Sr^m and opposite energy dependence of ⁸⁶Sr(n,γ)⁸⁷Sr^m and ⁸⁷Sr(n,n′)⁸⁷Sr^m reactions makes ^natSr an excellent candidate for neutron flux monitor for wide neutron energy range. The measured (n,γ) cross-section data from the present study has been compared with the literature data, which is very limited along with large scatter in the energy range of 1–2 MeV for these nuclei. The results from the present study, clearly show a need for fresh cross-section evaluations for ¹⁵²Sm(n,γ)¹⁵³Sm. For, ¹⁵⁴Sm(n,γ)¹⁵⁵Sm and ¹⁵⁰Nd(n,γ)¹⁵¹Nd reactions, the present data align with one of the data groups among the two which can be broadly identified having difference of about more than ∼50%. The present experimental data has been compared with TALYS 1.96 theoretical model calculations based on Fermi gas level density prescriptions which shows that the cross section values are close to the experimental data at some of the neutron energies. A comparison of the data on fast neutron capture cross-section for N = 90 isotones from the present study and from the literature showed a systematic decrease in the cross-section value with increasing neutron richness of the target nucleus. The cross-section data could be scaled with neutron-proton asymmetry parameter to show a nearly linear behaviour on a logarithmic scale. The data for ¹⁵⁴Sm (N = 92) was also observed to follow the same trend.

中子能下稀土稳定裂变产物 ¹⁵² Sm、 ¹⁵⁴ Sm、 ¹⁵⁰ Nd的(n,γ)反应截面0.8 至 2 MeV 范围，由 ⁷ Li(p,n) ⁷ Be 反应获得，通过中子活化和离线伽马射线光谱测定来测量。在这项工作中，通过测量 ^nat Sr(n,γ+n,n′) ⁸⁷ 反应截面，使用 ¹²⁷ I(n,γ) ¹²⁸ I 作为监测反应。据我们所知， ⁸⁶ Sr(n,γ) ⁸⁷ Sr ^m 的横截面首次被确定。 ⁸⁷ Sr ^m 具有优异的衰变特性，而 ⁸⁶ Sr(n,γ) ⁸⁷ Sr ^m Sr(n,n′) ⁸⁷ Sr ^m 反应使 ^nat Sr 成为中子通量监测器的绝佳候选者适用于宽中子能量范围。本研究中测得的 (n,γ) 截面数据与文献数据进行了比较，文献数据非常有限，而且这些原子核在 1-2 MeV 的能量范围内分散较大。本研究的结果清楚地表明需要对 ¹⁵² Sm(n,γ) ¹⁵³ Sm 进行新的横截面评估。对于 ¹⁵⁴ Sm(n,γ) ¹⁵⁵ Sm 和 ¹⁵⁰ Nd(n,γ) ¹⁵¹ Nd 反应，现有数据与两个数据组中的一个数据组一致，可以广泛地识别出其差异大约超过~50%。目前的实验数据已与TALYS 1进行了比较。96 基于费米气体能级密度公式的理论模型计算表明，截面值接近于某些中子能量下的实验数据。对本研究和文献中 N = 90 等位素的快中子俘获截面数据进行比较表明，随着目标核中子丰度的增加，截面值会系统性降低。横截面数据可以用中子-质子不对称参数进行缩放，以在对数尺度上显示近线性的行为。 ¹⁵⁴ Sm (N = 92) 的数据也观察到遵循相同的趋势。