Liquid drop model and effects of electronic energy loss on radiation damage cascades

Abstract

We present two aspects of the thermal behaviour of cascades, related to the mechanisms of heat transport. The first aspect concerns the PKA energy range where subcascades are produced and discusses the thermal interaction between them. For this description we couple the results of the Binary Collision Approximation (BCA) to a simplified solution of the heat equation. Comparison with Molecular Dynamics (MD) results when available supports this approach. However this analysis only considers lattice conductivity, neglecting the possible effects of electronic transport. In the second part of this presentation we consider the effects of the electronic energy loss on the dynamics of thermal spikes in Cu. This study is based on a simple model of the stopping power and the electron phonon interaction in the framework of the Embedded Atom Model (EAM) for MD. This approach is only valid for weak-coupling systems, like Cu, where we obtain quantitative information on the effect.

Key Words:

• radiation damage
• computer simulations
• collision cascades
• stopping power