Molecular dynamics simulations of helium cluster formation in tungsten

Molecular dynamics simulations of helium implantation into single-crystalline tungsten at 0 and 300 K have been performed. Non-damaging ion energies of 50, 100 and 200 eV were used. Clusters containing up to the order of 100 He atoms were formed. These clusters were nucleated athermally, via the creation of (1 1 1) crowdion interstitials and interstitial dislocation loop punching. Ruptures of He clusters were observed, but no associated ejection of W atoms.