  The threshold displacement energy (TDE) is the minimum amount of kinetic
energy required to displace an atom from its lattice site. The magnitude of the
TDE displays significant variance as a function of the crystallographic
direction, system temperature and applied strain, among a variety of other
factors. It is critically important to determine an accurate value of the TDE
in order to calculate the total number of displacements due to a given
irradiation condition, and thus to understand the materials response to
irradiation. In this study, molecular dynamics simulations have been performed
to calculate the threshold displacement energy in body-centered cubic iron as a
function of strain and temperature. With applied strain, a decrease of the TDE
of up to approximately 14 eV was observed. A temperature increase from 300 K to
500 K can result in an increase of the TDE of up to approximately 9 eV.
