^(197) Au中子辐射俘获过程中γ射线 强度函数与能谱研究

Study on γ-Ray Strength Functions and Energy Spectra in the Neutron Radiative Capture of ^(197)Au

文章假定在复合核首次和级联γ退激过程中，除包含巨偶极共振模式外，还存在６Ｈｅ，６Ｌｉ，６Ｂｅ，７Ｌｉ和７Ｂｅ等粒子集团的激发态的退激过程，并据此建立了包括这些过程的γ射线强度函数，计算了入射中子能量在０．０１—３ＭｅＶ能区的中子辐射俘获反应：１９７Ａｕ（ｎ，γ）的反应截面和γ能谱，得到了与实验数据较好符合的结果．特别是，很好地解释了γ能谱中５．５ＭｅＶ之后的反常突起．

The aim of this paper is to explain theoretically the abnormal protuberances near and after 5 .5 MeV in the gamma spectra of the (n, γ) reactions for the nulei in the regions of 110 ≤ A≤140 and 180 ≤ A ≤210. Supposing that in the primary and cascade gamma de-excitation processes of the compound nu- cleus, besides the giant dipole resonance model, there exist the deexcitation processes of the excited states of 6He, 6li,6Be, 7Li and 7Be particle Clusters, the γ-ray strength function in which these pro- cesses are contained was constructed. The (n ,γ) reaction cross sections and the gamma energy spec- tra in the neutron incident energy region from 0 .01 MeV to 3MeV for 197 Au were calculated. The re- suIts are in better coincidence with the experiments. Especially for the gamma energy spectra, the abnormal protuberances near and after 5 .5MeV were reproduced very well.