Excitation functions and isomeric cross section ratios of the 63Cu(n, alpha )60Com,g, 65Cu(n, alpha )62Com,g, and 60Ni(n,p)60Com,g processes from 6 to 15 MeV.
Excitation functions and isomeric cross section ratios of the 63Cu(n, alpha )60Com,g, 65Cu(n, alpha )62Com,g, and 60Ni(n,p)60Com,g processes from 6 to 15 MeV.
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DOI：
10.1103/physrevc.49.1525
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发表时间：
1994-03
影响因子：
3.1
通讯作者：
Cserpák;Sudár;Csikai;Qaim
中科院分区：
文献类型：
--
作者：
Cserpák;Sudár;Csikai;Qaim
测量了Cu 63 (n, α) 60 Co m、Cu 65 (n, α) 62 Co m和Cu 65 (n, α) 62 Co g反应在6.3 ~ 14.8 MeV中子能量范围内的激发函数。将活化技术与高分辨率γ射线光谱技术相结合。中子是通过在可变能量紧凑回旋加速器（en = 6.3-11.9 MeV）上使用氘气体靶的h2 (d, n) 3 He反应和在中子发生器（en = 13.7-14.8 MeV）上使用固体Ti-T靶的h3 (d, n) 4 He反应产生的。根据已有的实验数据，测定了Cu 63 （n, α）和Ni 60 （n, p）反应中Co m对的同分异构体截面比为60 g， Cu 65 （n, α）反应中Co m对的同分异构体截面比为62 g。考虑到预复合效应的统计模型计算对产物的异构体和基态的形成进行了计算。（n, p）和（n, α）总截面的计算结果与实验数据吻合较好；然而，在同分异构体状态的情况下，会出现一些偏差。计算得到的实验同分异构体截面比只能近似再现；在15mev时，能级密度的自旋分布对计算有显著影响。对于低洼能级，同分异构体截面比强烈地依赖于所涉及能级的自旋，而不是它们的激发能。在给定的中子能量下，（n, α）反应中高自旋同分异构体的居群高于（n, p）反应。
Excitation functions were measured for the Cu 63 (n, α) 60 Co m, Cu 65 (n, α) 62 Co m, and Cu 65 (n, α) 62 Co g reactions over the neutron energy range of 6.3 to 14.8 MeV. Use was made of the activation technique in combination with high resolution γ-ray spectroscopy. The nuetrons were produced via the H 2 (d, n) 3 He reaction using a deuterium gas target at a variable energy compact cyclotron (E n= 6.3–11.9 MeV) and via the H 3 (d, n) 4 He reaction using a solid Ti-T target at a neutron generator (E n= 13.7–14.8 MeV). From the available experimental data isomeric cross section ratios were determined for the isomeric pair Co m, 60 g in Cu 63 (n, α) and Ni 60 (n, p) reactions, and for the pair Co m, 62 g in the Cu 65 (n, α) reaction. Statistical model calculations taking into account precompound effects were performed for the formation of both the isomeric and ground states of the products. The calculational results on the total (n, p) and (n, α) cross sections agree well with the experimental data; in the case of isomeric states, however, some deviations occur. The experimental isomeric cross section ratios are reproduced only approximately by the calculation; at 15 MeV the spin distribution of the level density has a significant effect on the calculation. For low-lying levels the isomeric cross section ratio depends strongly on the spins of the levels involved and not on their excitation energies. At a given neutron energy the population of the higher spin isomer appears to be higher in the (n, α) process than in the (n, p) reaction.