ABSTRACT To estimate the structural damages of materials in accelerator facilities, displacement per atom (dpa) is widely employed as a damage index, calculated based on the displacement cross-section obtained using a calculation model. Although dpa is applied as standard, the experimental data of the displacement cross-section for a proton in the energy region above 20 MeV are scarce. Among the calculation models, difference of about factor 8 exist, so that the experimental data of the cross-section are crucial to validate the model. To obtain the displacement cross-section, we conducted experiments at the Japan Proton Accelerator Research Complex (J-PARC). The displacement cross-section of copper and iron was successfully obtained for a proton projectile with the kinetic energies, 0.4, 0.8, 1.3, 2.2, and 3 GeV. The results were compared with those obtained using the widely utilized Norgertt–Robinson–Torrens (NRT) model and the athermal–recombination–corrected dpa (arc-dpa) model based on molecular dynamics (MD). It was found that the NRT model overestimates the present displacement cross-section by 3.5 times. The calculation results obtained using with the arc-dpa model based on the Nordlund parameter show remarkable agreement with the experimental data. It can be concluded that the arc-dpa model must be employed for the dpa calculation for the damage estimation of copper and iron.

中文翻译：

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测量动能范围为 0.4 – 3 GeV 的质子的铜和铁的位移截面

摘要 为了估计加速器设施中材料的结构损伤，每原子位移 (dpa) 被广泛用作损伤指数，基于使用计算模型获得的位移截面进行计算。尽管 dpa 作为标准应用，但质子在 20 MeV 以上能量区域的位移截面的实验数据很少。在计算模型中，存在大约 8 倍的差异，因此横截面的实验数据对于验证模型至关重要。为了获得位移截面，我们在日本质子加速器研究中心 (J-PARC) 进行了实验。成功获得了动能为 0.4、0.8、1.3、2.2 和 3 GeV 的质子弹丸的铜和铁的位移截面。将结果与使用广泛使用的 Norgertt-Robinson-Torrens (NRT) 模型和基于分子动力学 (MD) 的无热复合校正 dpa (arc-dpa) 模型获得的结果进行比较。发现 NRT 模型高估了当前的位移截面 3.5 倍。使用基于Nordlund参数的arc-dpa模型得到的计算结果与实验数据非常吻合。可以得出结论，对于铜和铁的损伤估计，dpa 计算必须采用arc-dpa 模型。使用基于Nordlund参数的arc-dpa模型得到的计算结果与实验数据非常吻合。可以得出结论，对于铜和铁的损伤估计，dpa 计算必须采用arc-dpa 模型。使用基于Nordlund参数的arc-dpa模型得到的计算结果与实验数据非常吻合。可以得出结论，对于铜和铁的损伤估计，dpa 计算必须采用arc-dpa 模型。