摘要
Computer simulations are routinely performed to model the response of materials to extreme environments,such as neutron(or ion)irradiation.The latter involves high-energy collisions from which a recoiling atom creates a so-called atomic displacement cascade.These cascades involve coordinated motion of atoms in the form of supersonic shockwaves.These shockwaves are characterized by local atomic pressures 415 GPa and interatomic distances o2Å.Similar pressures and interatomic distances are observed in other extreme environment,including short-pulse laser ablation,high-impact ballistic collisions and diamond anvil cells.Displacement cascade simulations using four different force fields,with initial kinetic energies ranging from 1 to 40 keV,show that there is a direct relationship between these high-pressure states and stable defect production.An important shortcoming in the modeling of interatomic interactions at these short distances,which in turn determines final defect production,is brought to light.
