Towards a standardised methodology of radiation damage defect distributions for microstructure evolution models

We have developed a model that integrates molecular dynamics (MD) and binary collision approximation (BCA) results to reconstruct the irradiation damage caused by ions of any energy in different materials. The methodology is designed as a standardized tool for introducing defects into microstructure evolution models, such as object kinetic Monte Carlo or cluster dynamics. Our approach combines primary knock-on atom (PKA) energy and position data from the BCA code SRIM with the CascadesDB database of MD cascade debris. For energies below the database energy limit, the fer-arc-dpa model (Yang, 2021) is employed to estimate Frenkel pair production; and for energies above it, SRIM is run iteratively. The code also incorporates methods for defect and cluster identification, facilitating detailed analysis of the MD database and the reconstructed damage. We demonstrate its application by comparing defect production to displacement per atom models and analysing cluster distributions for self-ion irradiation at 1 and 5 MeV in Fe and W. While focused on ion irradiation, the framework is adaptable to neutron irradiation, provided that the PKA data are available; and it can be extended to other MD databases or BCA codes.