CALIBRATING A MULTIMODEL APPROACH TO DEFECT PRODUCTION IN HIGH-ENERGYCOLLISION CASCADES

A multi-model approach to simulating defect production processes at th e atomic scale is described that incorporates molecular dynamics (MD), binary collision approximation (BCA) calculations and stochastic anne aling simulations. The central hypothesis is that the simple, fast com puter codes capable of simulating large numbers of high energy cascade s (e.g., BCA codes) can be made to yield the correct defect configurat ions when their parameters are calibrated using the results of the mor e physically realistic MD simulations. The calibration procedure is in vestigated using results of MD simulations of 25 keV cascades in coppe r. The configurations of point defects are extracted from the MD casca de simulations at the end of the collisional phase, thus providing inf ormation similar to that obtained with a binary collision model. The M D collisional phase defect configurations are used as input to the ALS OME annealing simulation code, and values of the ALSOME quenching para meters are determined that yield the best fit to the post-quenching de fect configurations of the MD simulations.