Low energy and low fluence helium implantations in tungsten: Molecular dynamics simulations and experiments

• Published in: Journal of nuclear materials Vol. 470; pp. 44 - 54
• Main Authors: Pentecoste, L., Brault, P., Thomann, A.-L., Desgardin, P., Lecas, T., Belhabib, T., Barthe, M.-F., Sauvage, T.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-03-2016; Elsevier
• Subjects: Atomic properties; Engineering Sciences; Helium; Helium retention; Implantation; Low energy; Materials; Molecular dynamics; Plasma-wall interactions; Plasmas; Saturation; Simulation; Tungsten; Molecular dynamics; Plasma-wall interactions; Helium retention; Molecular Dynamics; plasma-wall interactions
• ISSN: 0022-3115; 1873-4820
• DOI: 10.1016/j.jnucmat.2015.12.017

300 eV Helium implantation process into tungsten at 300 K has been studied with molecular dynamic simulations (MD). Predicted retention doses were compared to that obtained from experiments performed in equivalent conditions. A saturation phenomenon of the helium retention was evidenced for a number of impinging He atoms and a retention dose similar in both, experiments and simulations. From MD simulations it is learnt that observed Helium diffusion, formation and coalescence of clusters are the phenomena leading to the flaking of the substrate. These processes could explain the saturation of the Helium retention observed experimentally at low energies.
•MD simulations give He retention rate decreasing with increasing incident He number.•MD simulations reveal He saturation level in W close to experiments.•MD simulations show W flaking due to He accumulation.•MD simulations show stratification phenomena of the He depth distribution in W.