Takeuchi T
Radioisotopes. 1980 Mar;29(3):119-23. doi: 10.3769/radioisotopes.29.3_119.
Some effects of self-shielding of neutron flux in neutron activation analysis have been investigated. Induced specific activities in dilute samples were compared with those in solid elements irradiated under the same conditions. Two factors affecting the neutron flux were investigated: thermal neutron self-shielding and epithermal neutron self-shielding. The former effect can be computed reasonably accurately, using a well-known approximation. Self-shielding of epithermal neutrons cannot be calculated rigorously, so an empirical approach was used. The self-shielding effects of neutron flux were evaluated for uranium and a maximum permissible weight has been calculated by assuming that the product of the maximum permissible weight and the atom density is a function of the ratio of the resonance integral of the absorbing element to that of uranium.
已对中子活化分析中中子通量的自屏蔽效应进行了一些研究。将稀释样品中的感生比活度与在相同条件下辐照的固体元素中的比活度进行了比较。研究了影响中子通量的两个因素：热中子自屏蔽和超热中子自屏蔽。前一种效应可以使用一种众所周知的近似方法相当准确地计算出来。超热中子的自屏蔽无法严格计算，因此采用了一种经验方法。对铀的中子通量自屏蔽效应进行了评估，并通过假设最大允许重量与原子密度的乘积是吸收元素的共振积分与铀的共振积分之比的函数，计算出了最大允许重量。
