The confusing issue of the neutron capture cross-section to use in thermal neutron self-shielding computations
The confusing issue of the neutron capture cross-section to use in thermal neutron self-shielding computations
复制标题
热中子自屏蔽计算中使用的中子俘获截面的令人困惑的问题
DOI：
10.1016/0168-9002(94)01316-0
复制
发表时间：
1995
影响因子：
1.4
通讯作者：
M. Blaauw
中科院分区：
文献类型：
--
作者：
M. Blaauw
在没有散射的情况下，如果材料的宏观热吸收截面已知，就可以修正中子活化实验中出现的热中子自屏蔽。人们普遍认为，用于此目的的平均截面〈Σ〉与速度为2200m/S的中子的平均截面Σ相差φ2倍。在本文中，证明了在薄样情况下使用的正确因子不是φ2，而是2φ。文中还给出了计算中厚样品自屏蔽系数的经验公式。
In the absence of scattering, the thermal neutron self-shielding as occurs in neutron activation experiments can be corrected for if the macroscopic thermal absorption cross-section of the material is known. It is generally accepted that the average cross-section 〈 Σ 〉 to be used for this purpose differs from the cross-section Σ0for neutrons with a velocity of 2200 m/s by a factor of φ 2 . In this paper, it is shown that the correct factor to use in the case of thin samples is not φ 2 , but 2 φ . An empirical formula for the computation of self-shielding factors for samples of intermediate thickness is also presented.