In the present research,molecular dynamics simulation is applied to study the interactions between tungsten dusts and a beryllium plasma-facing material surface.Calculation results show that it is quite difficult for ...In the present research,molecular dynamics simulation is applied to study the interactions between tungsten dusts and a beryllium plasma-facing material surface.Calculation results show that it is quite difficult for nanometer-size dust particles to damage the plasma-facing material surface,which is different from the micrometer-size ones.The reason may be the size difference between dust and crystal grains.The depth of dust penetration into plasma-facing materials is closely related to the incident velocity,and the impacting angle also plays an important role.Dust and material surface damage is also investigated.Results show that both incident velocity and angle can significantly influence the damage.展开更多
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 be...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.展开更多
Classical molecular dynamics has been used to study the interactions between tung- sten （W） plasma-facing materials （PFMs） and dust grains. The impact velocity of dust grains is in the range from 324 m/s to 3240 m...Classical molecular dynamics has been used to study the interactions between tung- sten （W） plasma-facing materials （PFMs） and dust grains. The impact velocity of dust grains is in the range from 324 m/s to 3240 m/s. The main effect of dust grains with low impact velocity is deposition. However, a material surface can be damaged by high velocity dust grains. The cumulative damage of impacting dust grains has also been take into account. When the impact velocity is low, no significant damage is detected but a porous firm forms on the surface. Serious damage can be produced on PFMs if the impact velocity is high.展开更多
基金supported by the National Magnetic Confinement Fusion Science Program of China(Nos.2013GB105001,2013GB105002,and 2015GB109001)National Natural Science Foundation of China(Nos.11205198,11305213 and 11405201)Technological Development Grant of Hefei Science Center of CAS(No.2014TDG-HSC003)
文摘In the present research,molecular dynamics simulation is applied to study the interactions between tungsten dusts and a beryllium plasma-facing material surface.Calculation results show that it is quite difficult for nanometer-size dust particles to damage the plasma-facing material surface,which is different from the micrometer-size ones.The reason may be the size difference between dust and crystal grains.The depth of dust penetration into plasma-facing materials is closely related to the incident velocity,and the impacting angle also plays an important role.Dust and material surface damage is also investigated.Results show that both incident velocity and angle can significantly influence the damage.
基金supported by National Natural Science Foundation of China(Nos.51171008 and 11405201)the National Magnetic Confinement Fusion Program of China(No.2013GB1090)
文摘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.
基金supported by National Natural Science Foundation of China(No.11075186)National Magnetic Confinement Fusion Science Program of China(No.2013GB107004)
文摘Classical molecular dynamics has been used to study the interactions between tung- sten （W） plasma-facing materials （PFMs） and dust grains. The impact velocity of dust grains is in the range from 324 m/s to 3240 m/s. The main effect of dust grains with low impact velocity is deposition. However, a material surface can be damaged by high velocity dust grains. The cumulative damage of impacting dust grains has also been take into account. When the impact velocity is low, no significant damage is detected but a porous firm forms on the surface. Serious damage can be produced on PFMs if the impact velocity is high.
