Atomic scale computer simulations are used to investigate the intracas
cade evolution of the defect populations produced in cascades in coppe
r over macroscopic time scales. Starting with cascades generated using
molecular dynamics, the diffusive transport and interactions of the d
efects are followed for hundreds of seconds in stochastic annealing si
mulations. The temperature dependencies of annihilation, clustering an
d free defect production are determined for individual cascades, espec
ially including the effects of the subcascade structure of high energy
cascades. The subcascade structure is simulated by closely spaced gro
ups of lower energy MD cascades. The simulation results illustrate the
strong influence of the defect configuration existing in the primary
damage state on subsequent intracascade evolution. Other significant f
actors affecting the evolution of the defect distribution are the larg
e differences in mobility and stability of vacancy and interstitial de
fects and the rapid one-dimensional diffusion of small, glissile inter
stitial clusters produced directly in cascades. Annealing simulations
are also performed on high-energy, subcascade-producing cascades gener
ated with the binary collision approximation and calibrated to MD resu
lts. (C) 1997 Elsevier Science B.V.