Theoretical models often differ significantly from measured data in their predictions of the magnitude of nuclear reactions that produce radionuclides for medical, research, and national security applications. In this paper, we compare a priori predictions from several state-of-the-art reaction modeling packages (CoH, EMPIRE, TALYS, and ALICE) to cross sections measured using the stacked-target activation method. The experiment was performed using the Lawrence Berkeley National Laboratory 88-Inch Cyclotron with beams of 25 and 55 MeV protons on a stack of iron, copper, and titanium foils. Thirty-four excitation functions were measured from 4–55 MeV, including the first measurement of the independent cross sections for \(^{\mathrm{nat}}\hbox {Fe}\)(p,x)\(^{49,51}\hbox {Cr}\), \(^{51,{\mathrm{52m}},{\mathrm{52g}},56}\hbox {Mn}\), and \(^{{\mathrm{58m,58g}}}\hbox {Co}\). All of the models, using default input parameters to assess their predictive capabilities, failed to reproduce the isomer-to-ground state ratio for reaction channels at compound and pre-compound energies, suggesting issues in modeling the deposition or distribution of angular momentum in these residual nuclei.

理论模型在预测产生用于医疗，研究和国家安全应用的放射性核素的核反应的幅度时，通常与实测数据存在显着差异。在本文中，我们将几种最先进的反应建模程序包（CoH，EMPIRE，TALYS和ALICE）与使用堆叠目标激活方法测得的横截面进行先验预测进行比较。实验是使用劳伦斯伯克利国家实验室88英寸回旋加速器在铁，铜和钛箔叠层上用25和55 MeV质子束进行的。从4–55 MeV测量了34个激发函数，包括对\（^ {\ mathrm {nat}} \ hbox {Fe} \）（p，x）的独立横截面的首次测量\（^ {49,51} \ hbox {Cr} \），\（^ {51，{\ mathrm {52m}}，{\ mathrm {52g}}，56} \ hbox {Mn} \）和\ （^ {{\ mathrm {58m，58g}}} \ hbox {Co} \）。所有使用默认输入参数评估其预测能力的模型均未能重现化合物和预化合物能量下反应通道的异构体与基态之比，从而提示了在这些角动量的沉积或分布建模时存在的问题残留核。