Radiation damage has traditionally been modelled using classical molecular dynamics,
in which the role of the electrons is con�fined to describing bonding via the interatomic
potential. This is generally sufficient for low radiation energies. However high energy
atoms lose a signi�ficant proportion of their energy to electronic excitations, therefore a
simulation of the relaxation of a metallic lattice after a high energy event requires a description
of the energetic interaction between atoms and electrons. The mechanisms of
inelastic collisions between electrons and ions, coupling between electrons and phonons
and the di�ffusion of energy through the electronic system to the rest of the lattice become
signfi�cant.
We have coupled large scale MD simulations of the lattice to a continuum model for
the electronic temperature evolution. Energy lost by the atoms due to elastic and inelastic
electronic collisions is gained by the electronic system and evolves according to a heat
di�ffusion equation. The electronic energy is coupled to the lattice via a modifi�ed Langevin
thermostat, representing electron-phonon coupling.
Results of the simulation of both displacement cascades and ion tracks, representing
the low and high extremes of incident ion energy respectively, are presented. The eff�ect
of annealing of pre-existing damage by electronic excitation is studied and the behaviour
under swift heavy ion irradiation in iron and tungsten is compared. In simulations of
displacement cascades, the strength of coupling between the atoms and electrons emerges
as the main parameter determining residual damage. Our new methodology gives rise
to reduced damage compared to traditional methods in all cases. Ion track simulations
demonstrated that the relaxation dynamics, and hence the residual damage, was dependent
on the magnitude and temperature dependence of the electronic thermal parameters
