The effect of electron–ion interactions on radiation damage simulations

Abstract

Classical cascade simulations of radiation damage generally neglect the effect of energy exchange between the lattice and the electrons; however electronic effects increase with increasing radiation energy. Indeed, even for low energy radiation events the electrons contribute to heat transport and increase the cooling rate, particularly in materials with strong electron–ion interactions. We use a method described in an earlier publication to include these effects in a series of 10 keV cascades in Fe, for a range of electron–ion interaction strengths. We find a non-monotonic relationship between the number of residual defects and the strength of the electron–ion interactions and we discuss the mechanisms involved.

Development of an electron-temperature-dependent interatomic potential for molecular dynamics simulation of tungsten under electronic excitation

“…This relates to the framework currently used in two-temperature model molecular dynamics ͑2TM-MD͒ simulations. [36][37][38][39][40][41][42][43][44] In such treatments, the electronic temperature is typically defined within coarse-grained electron temperature cells ͑Refs. 42-44͒, each of which contains approximately 10 2 -10 3 atoms.…”

Simulating electronically driven structural changes in silicon with two-temperature molecular dynamics

“…It follows from the fluctuation-dissipation theorem [42][43][44] that when the electrons and nuclei are in thermal equilibrium with each other, μ = 2γ k B T e , where k B is Boltzmann's constant. As with previous work [45,46], we make the assumption that this relation holds true even out of equilibrium. The damping parameter γ may then be chosen such that the electronic and nuclear temperatures converge on a desired timescale after being driven from equilibrium.…”

Atomistic simulation of laser ablation of gold: The effect of electronic pressure

“…Molecular dynamics (MD) models of the twotemperature (2T) system proposed in [9,10,11] consist in considering the ES as a continuum. The energy transfer from the ES to the IS is implemented using a Langevin thermostat.…”

“…is the Langevin force that models the electron-ion energy transfer [11], the last term in (2) is the blast force [13,14] and n i is the locally averaged ionic density. Note that the local variations of the ETD-potential with T e change the local properties of the IS (e.g.…”