For a few decades now, molecular dynamics (MD) simulations have been extensively used for studying primary damage formation in collision cascades in materials exposed to fast particle irradiation. Because of the stochastic nature of defect production phenomena, it is vital to model collision cascades in batches with the same set of essential simulation parameters that includes primary knock-on atom (PKA) energy and target temperature in the first instance. No generally accepted practice has been established so far to determine the optimal size of the sampling set of MD simulations of collision cascades. The suggested simple a posteriori sampling set size validation method is based on reviewing the dependence of the average and median number of Frenkel pairs generated in collision cascades on the amount n of simulated cascades in a series with identical simulation parameters. As the average and median number of Frenkel pairs converges with raising n, the optimal sampling set size is determined as a function of the simulation conditions. It is shown how it depends on the PKA energy, irradiation temperature, alloy composition and the interaction of collision cascades with the free surfaces.

几十年来，分子动力学（MD）模拟已广泛用于研究暴露于快速粒子辐照的材料中碰撞级联中主要损伤的形成。由于缺陷产生现象的随机性质，至关重要的是，使用相同的一组基本仿真参数（首先包括主敲除原子（PKA）能量和目标温度）来批量建模碰撞级联。迄今为止，尚未建立公认的实践来确定碰撞级联的MD模拟的采样集的最佳大小。建议的简单后验采样集大小验证方法是基于对碰撞级联中生成的Frenkel对的平均值和中位数对数量的依赖关系一系列具有相同模拟参数的模拟级联中的n个。随着Frenkel对的平均数和中位数随着n的增加而收敛，根据模拟条件确定最佳采样集大小。它显示了它如何取决于PKA能量，辐照温度，合金成分以及碰撞级联与自由表面的相互作用。