中文摘要：

Hydrogen(H) defect interactions have been investigated by molecular statics simulations in tungsten(W),including H-H interactions and interactions between H and W selfinterstitial atoms.The interactions between H and small H-vacancy clusters are also demonstrated;the binding energies of an H,a vacancy and a self-interstitial W to an H-vacancy cluster depend on the H-to-vacancy ratio.We conclude that H bubble formation needs a high concentration of H in W for the H bubble nucleation and growth,which are also governed by the H-to-vacancy ratio of the cluster.The vacancy first combines with H atoms and a cluster forms,then the H-vacancy cluster goes through the whole process of vacancy capture,H capture,and vacancy capture again,and as a result the H-vacancy cluster grows larger and larger.Finally,the H bubble forms.

英文摘要：

Hydrogen （H） defect interactions have been investigated by molecular statics sim- ulations in tungsten （W）, including H-H interactions and interactions between H and W self- interstitial atoms. The interactions between H and small H-vacancy clusters are also demonstrated; the binding energies of an H, a vacancy and a self-interstitial W to an H-vacancy cluster depend on the H-to-vacancy ratio. We conclude that H bubble formation needs a high concentration of H in W for the H bubble nucleation and growth, which are also governed by the H-to-vacancy ratio of the cluster. The vacancy first combines with H atoms and a cluster forms, then the H-vacancy cluster goes through the whole process of vacancy capture, H capture, and vacancy capture again, and as a result the H-vacancy cluster grows larger and larger. Finally, the H bubble forms.