Molecular dynamics simulations have been performed to investigate the defect structure evolution at different development stages of atomic displacement cascades with energies up to 50 keV in iron crystallites in the temperature range from 300 to 900 K. The number of surviving radiation defects in iron crystallites increases according to a power law with increasing energy of the primary knocked-on atom. An increase in the crystallite temperature slightly increases the number of surviving defects. It is found that atomic displacement cascades can lead to radiation-induced grain boundary migration due to the melting and crystallization of the radiation-damaged region. The crystallographic orientation of the irradiated free surface strongly affects the radiation damage behavior. Craters with adatom islands are formed on the (111) free surface, and vacancy loops are nucleated in the (110) near-surface region. Point defects aggregate into clusters of various types during the evolution of atomic displacement cascades. It is shown that the number of surviving point defect clusters can significantly decrease under uniaxial elastic compression.

中文翻译：

---

辐照下具有晶界的金属中点缺陷簇的形成

已进行分子动力学模拟以研究在 300 至 900 K 温度范围内，铁微晶中能量高达 50 keV 的原子位移级联不同发展阶段的缺陷结构演变。铁微晶中幸存的辐射缺陷数量增加随着初级碰撞原子的能量增加，服从幂律。微晶温度的增加略微增加了残留缺陷的数量。研究发现，由于辐射损伤区域的熔化和结晶，原子位移级联会导致辐射诱导的晶界迁移。受辐照自由表面的晶体取向强烈影响辐射损伤行为。在（111）自由面上形成具有吸附原子岛的陨石坑，和空位环在（110）近地表区域成核。在原子位移级联的演化过程中，点缺陷聚集成各种类型的簇。结果表明，在单轴弹性压缩下，幸存的点缺陷簇的数量可以显着减少。