Abstract

The process of the photoemission of one, two, three and four neutrons from the ²⁰⁹Bi nuclei with producing, respectively, ²⁰⁸Bi, ²⁰⁷Bi, ²⁰⁶Bi and ²⁰⁵Bi daughter radioisotopes was investigated at the end-point energies of \(E_{\gamma }^{{\max }}\) = 30 and 40 MeV of bremsstrahlung photons at the AANL (YerPhI) linear electron accelerator. Particularly, for the relative yields of ²⁰⁸Bi/²⁰⁷Bi, ²⁰⁶Bi/²⁰⁷Bi and ²⁰⁵Bi/²⁰⁷Bi the following values were obtained: 10.8 ± 2.2, 0.060 ± 0.002 and (1.45 ± 0.53)×10^–4 at \(E_{\gamma }^{{\max }}\) = 30 MeV and 6.1 ± 0.5, 0.120 ± 0.006 and 0.0216 ± 0.0016 at \(E_{\gamma }^{{\max }}\) = 40 MeV, respectively. It is shown that the predictions of the TALYS model, as well as the model which is contained in the GEANT4 package are in a contradiction with the experimental data. For instance, the predictions of GEANT4 at \(E_{\gamma }^{{\max }}\) = 40 MeV for relative yields of ²⁰⁸Bi/²⁰⁷Bi and ²⁰⁵Bi/²⁰⁷Bi and the prediction of TALYS for ²⁰⁵Bi/²⁰⁷Bi about twice are smaller than the experimental values. At \(E_{\gamma }^{{\max }}\) = 30 MeV, the predictions of both models for ²⁰⁵Bi/²⁰⁷Bi about two order of magnitude are smaller than the experimental values.

中文翻译：

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铋中一个或多个中子光发射反应的研究

摘要

研究了从²⁰⁹ Bi核中分别产生²⁰⁸ Bi，²⁰⁷ Bi，²⁰⁶ Bi和²⁰⁵ Bi子放射性同位素的²⁰⁹ Bi核中的一个，两个，三个和四个中子的光发射过程，其终点能量为\（E_ { \ gamma} ^ {{{\ max}} \） =在AANL（YerPhI）线性电子加速器上的30致辐射光子的30和40 MeV。特别是，对于相对产率²⁰⁸的Bi / ²⁰⁷的Bi，²⁰⁶铋/ ²⁰⁷ Bi和²⁰⁵的Bi / ²⁰⁷的Bi，得到以下值：10.8±2.2，0.060±0.002和（1.45±0.53）×10 ^-4在\（E _ {\ gamma} ^ {{\\ max}} \） = 30 MeV和\（E _ {\ gamma} ^ {{{\ max}} \） = 40时的6.1±0.5、0.120±0.006和0.0216±0.0016 MeV，分别。结果表明，TALYS模型的预测以及GEANT4软件包中包含的模型与实验数据相矛盾。例如，对于²⁰⁸ Bi / ²⁰⁷ Bi和²⁰⁵ Bi / ²⁰⁷ Bi的 相对产量，在\（E _ {\ gamma} ^ {{\\ max}} \） = 40 MeV处的GEANT4的预测和对于²⁰⁵ Bi的TALYS的预测/ ²⁰⁷ Bi大约两倍于实验值。在\（E _ {\ gamma} ^ {{\\ max}} \）在30 MeV = 30 MeV的情况下，两个模型对²⁰⁵ Bi / ²⁰⁷ Bi的大约两个数量级的预测小于实验值。