Atomic displacement damage energy model up to high recoil energy

Current analytical displacement damage models are derived for recoil energy below 24.9AZ4/3 keV. The present work studies the damage energy beyond this theoretical limit using SRIM Full Cascade (FC) and DART calculations. Notably, the three damage energies computed with different methods from the same SRIM simulation are not equal, whereas they are believed to be the same in principle. The method of directly subtracting the ionization energy from total recoil energy is recommended for both FC and Quick Calculation (QC) options. It is also observed that the damage energy seems to unphysically depend on the density of monatomic material in SRIM FC. While the classical analytical models imply the saturated damage energy for high recoil energy, this saturation is not observed in SRIM FC nor in the numerical solution of the Lindhard equation using reasonable electronic stopping powers.