Particle-induced erosion of materials at elevated temperature

The experimentally measured erosion rate of surfaces exposed to energetic particle bombardment at an elevated temperature exceeds that predicted by a summation of the physical sputtering rate and the thermodynamic sublimation/evaporation rate. A model based on the creation of surface adatoms, due to the energetic projectile bombardment of surfaces, and their subsequent sublimation/evaporation is developed to explain the enhanced erosion. Molecular dynamics simulations of beryllium confirm that the experimentally measured evaporation energy is consistent with the binding energy of adatoms. Experimental data of temperature-dependent erosion from both solid (beryllium) and liquid (lithium) samples are in agreement with the radiation activated adatom sublimation model.