Evaluation of threshold displacement energy of tungsten by molecular dynamics simulation

Threshold displacement energy (TDE) is an important quantity to determine the number of defects formed by irradiation of high-energy particles. For tungsten, different values of TDE have been reported in several studies, which caused discrepancy in calculated damage amounts. In the present study, we evaluated TDE using molecular dynamics simulation, where TDE is defined as the average value of minimum displacement energies to create a stable defect over all directions. In order to determine it accurately, effects of some calculation settings such as simulation cell size, the number of displacement directions and recoil energy increment value for average TDE calculating were analyzed. As a result, we obtained 83 eV as TDE of tungsten. This value is close to the one recommended value by American Society for Testing and Materials (ASTM) which is 90 eV. (authors)