Molecular dynamics analysis of volume change in a nuclear glass model subjected to a displacement cascade

In previous work, we presented the structural modifications induced in a si mplified nuclear glass by a displacement cascade generated by an heavy ion. In this work, we try to have a link between the macroscopic volume change of the nuclear glass and the structural modifications at the atomic scale. The analysis of the Voronoi cell volumes distribution for different species in our simplified nuclear glass, highlights that the swelling consecutive to a displacement cascade is concentrated around network modifiers. This ob servation corroborates well the experimental results where it is observed t hat an alkalino bore silicate glass shrinks under alpha radiations in the a bsence of any alkali oxide, and it swells as long as the [Na2O]/[SiO2] rati o increases. (C) 1999 Elsevier Science B.V. All rights reserved.