A combined BCA-MD method with adaptive volume to simulate high-energy atomic-collision cascades in solids under irradiation.

Graphical abstract Highlights • A BCA-MD method with adaptive volume to simulate cascades in solids is proposed. • The MD cell is adapted and optimized for each cascade using BCA results. • The BCA-MD reproduces very well the different phases of cascades. • The speedup of MD calculations achieved by the BCA-MD increases with the PKA energy. • A speedup of ×312 was estimated for a PKA energy of 0.5 MeV in Fe. Abstract We present a method combining the Binary Collision Approximation (BCA) and Molecular Dynamics (MD) with adaptive volume to simulate high-energy collision cascades in solids under irradiation. The results obtained with the BCA-MD method with adaptive volume are in very good agreement with those obtained with full MD calculations. The BCA-MD predicts very well in a broad range of Primary Knock-on Atom (PKA) energies the different phases of evolution of the cascade, the number of Frenkel pairs, the fraction of point defects in clusters and their size distribution. The BCA-MD method proposed here achieves a considerable acceleration of MD simulations with a speedup factor that increases with the PKA energy. For a PKA energy of 80 keV in Fe, the speedup measured is higher than 30. For a PKA energy of 0.5 MeV in Fe, by comparison with MD simulations performed by other authors, we estimate that the BCA-MD accelerates MD simulations by a factor 312. [ABSTRACT FROM AUTHOR]