A Molecular Dynamics Study of Helium-Vacancy Clusters Production due to Cascades in α-Iron
Molecular dynamics (MD) methods are utilized to study the displacement cascades in α-Fe containing different concentrations of substitutional He atoms. Primary knock-on atom (PKA) energies, Ep, from o.5 keV to 20 keV are considered at a temperature of 100 K and 600 K, and the results are compared with those performed in pure α-Fe. There are distinct differences in the number and size of defect clusters within displacement cascades with and without substitutional helium atoms. Particularly, the number and size of helium-vacancy clusters generally increase with increasing helium concentration and PKA energy. However, the number of He-vacancy (He-V) clusters increases with increasing temperature, the mean size of He-V clusters is independent on temperature for the same He concentration and energy recoils.
Young Won Chang, Nack J. Kim and Chong Soo Lee
L. Yang et al., "A Molecular Dynamics Study of Helium-Vacancy Clusters Production due to Cascades in α-Iron", Materials Science Forum, Vols. 561-565, pp. 1753-1756, 2007