It was noted that an extensive computer-simulation study of primary damage in displacement cascades in metals had shown that the total number of defects which was produced was appreciably lower than that predicted by the Norgett-Robinson-Torrens model, and that a large fraction of the self-interstitials formed glissile clusters. However, the poor variety of defect types found in cascade simulations made it difficult to explain the experimental data. Thus, experiments on Cu indicated the production of stacking-fault tetrahedra, but these were not so commonly observed in computer simulations. In order to address this problem, simulations were made of displacement cascades in Cu by using 2 different interatomic potentials. One was a short-range many-body potential and the other was a long-range pair potential. Primary knock-on atom energies of 2 to 20keV, and temperatures of 100 or 600K, were assumed. Particular attention was paid to cascade statistics and to the accuracy of the simulations during the collision stage. The former required many simulations for each energy, whereas the latter involved a modification of the simulation method so as to treat a hot region with greater accuracy by applying a smaller time-step. Results were obtained which indicated the presence of stacking-fault tetrahedra, glissile and sessile interstitial clusters, and faulted or perfect interstitial dislocation loops.

Defect Cluster Formation in Displacement Cascades in Copper. Y.N.Osetsky, D.J.Bacon: Nuclear Instruments and Methods in Physics Research B, 2001, 180[1-4], 85-90