Molecular Dynamics simulation of high energy cascades in β-SiC and metals

Results on displacement cascades simulation produced by primary recoil atoms (PKA) in β-SiC and metals (Au, Fe) are presented. Since β-Sic is expected to be a very serious candidate to become a structural component of blankets and fusion reactor walls, the necessity to study the behaviour of the latter under intense irradiation conditions is developed. Calculations have been performed with MDCASK code, making use of the Tersoff semi-empirical potential for covalent β-SiC, and Embedded Atom Model (EAM) for metals. The displacement effect of 3 and 5 keV PKA's at 300 and 1300 K has been simulated, obtaining not just the size of the corresponding cascades, but also conclusions on the excitation effect and on the different defects that appear in the two existing sub-lattices (C and Si) of the material. In addition, results of the accumulation of 25 PKA's, introduced within a 3 ps sequence with energies of 0.5 and 1 KeV, are enclosed. Whether simulated conditions resemble or not those existing in the material if it were submitted to irradiations such as those coming from inertial fusion targets micro-explosions,is discussed as well. As a consequence of a current programme of atomic basic simulation of radiation effects on steels, displacement threshold energies and Fe Cascades (BCC) simulations, along with results that lead to parameters necessary for subsequent Monte Carlo diffusion simulations, are presented. The Au case implies the embodiment of a high Z-FCC-like-material. (Author) 2 refs