Abstract

The weighted-average cross sections for \({}^{179m2}\)Hf and \({}^{180m}\)Hf population in (\(\gamma,\gamma^{\prime}\)) reactions induced by gamma rays of bremsstrahlung spectrum with endpoint energies of 17.5, 37, and 55 MeV were measured for the first time. A second maximum in the excitation function for the \(K\) forbidden isomers of \({}^{179}\)Hf and \({}^{180}\)Hf was found in the energy range between 20 and 35 MeV. A respective simulation was performed within the model of pre-equilibrium processes and within the statistical model by employing the TALYS-1.9 and EMPIRE-3.2 codes. It is shown that the integrated cross sections for (\(\gamma,\gamma^{\prime}\)) reactions in the energy range between 20 and 55 MeV are described in the statistical limit of the compound-nucleus volume (TALYS-1.9 code).

中文翻译：

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$ {K} $$异构体$$ {} ^ {{179m2}} $$ Hf和$$ {} ^ {{180m}} $$ Hf在（$$ {\ gamma，\ gamma ^ {\ prime}} $$）反应

摘要

（\（\ gamma，\ gamma ^ {\ prime} \））反应中\（{} ^ {179m2} \） Hf和\（{} ^ {180m} \） Hf群体的加权平均横截面首次通过endpoint致辐射光谱的伽玛射线测量了终点能量为17.5、37和55 MeV。在20至35的能量范围内，发现了\（{} ^ {179} \） Hf和\（{} ^ {180} \） Hf的\（K \）禁用异构体的激发函数中的第二个最大值MeV。通过使用TALYS-1.9和EMPIRE-3.2代码，在预平衡过程模型内和统计模型内分别进行了模拟。显示了（\（\ gamma，\ gamma ^ {\ prime} \）的集成横截面在20到55 MeV的能量范围内的反应在化合物核体积的统计极限中描述（TALYS-1.9代码）。