Modelling radiation damage and He production in tungsten

Tungsten is a candidate material for the divertor and for first wall armor of future thermonuclear fusion reactors (ITER and DEMO). In such irradiation conditions, it is well known that the microstructure, and as a result the properties of the materials, will evolve. In this perspective, the fate of irradiation-induced defects (helium atoms, vacancies, self-interstitials and the complexes they can form) has to be understood. In particular, He migration properties are of fundamental as well as practical interest, as they can affect the microstructure evolution and eventually influence physical and mechanical properties, the most significant example being high-temperature helium embrittlement. In this work, we show how our ab initio parameterized object kinetic Monte Carlo code LAKIMOCA can model the evolution, during implantation, of the point defect population in the track region of 800 keV He-3 atoms implanted in W samples. We also discuss possible improvements of the model.