Molecular dynamics simulation is an important tool for gaining insight into radiation damage eff­­ects in a way which is often not possible in experiments. Systems of interest include materials used in nuclear and future fusion reactors as well as materials to be used for safe encapsulation of nuclear waste. High-energy radiation damage in these systems has not been studied so far, yet it is important to simulate1. New energy and time scales will give a more realistic view of the phenomena that take place during the irradiation and possibly lead to observations of new effects.

DL_POLY MD code2, in combination with the massive parallel computing facilities of HECToR3, UK’s National Supercomputer, set the stage for simulating systems with up to 1 billion atoms, and therefore open the possibility to model radiation damage due to high energy recoils in the range between 100 keV up to 1 MeV.
We study the effects of high-energy radiation damage in iron4 and zirconia. We simulate recoil energies of 200-500 keV in systems of 20-300 million atoms. We investigate the dependence of the damage creation, evolution and recovery on time as well as the nature of the defects in the system.

1. M. Stoneham, J. R. Matthews and I. J. Ford, J. Phys.: Condens. Matter 16, S2597 (2004).
2. I.T. Todorov, W. Smith, K. Trachenko & M.T. Dove, `J. Mater. Chem.’, 16, 1911-1918 (2006).
3. http://www.hector.ac.uk
4. Nature of high-energy radiation damage in iron: Modelling results, E. Zarkadoula, M. T. Dove, K. Trachenko, et al, submitted for publication