Discovering highly radiation resistant plasma facing materials (PFM) is an urgent target for nuclear fusion reactor. In our previous work, a new PFM (nanochannel tungsten film) that consists of many tungsten crystal columns was found having excellent radiation tolerant properties. In the present work, three tungsten columns whose top surfaces are {100}, {110} and {111} -oriented were studied by molecular dynamics simulations and density functional theory calculations. We find that the tungsten columns whose top surfaces are {100}-oriented retain fewer helium atoms than the tungsten columns whose top surfaces are {110} or {111}-oriented. Moreover, the microstructural changes of tungsten columns whose top surfaces are {100}-oriented are smaller than others after high helium fluence exposure, which indicates that the nanochannel tungsten film maybe more suitable than bulk tungsten for plasma facing material in releasing helium atoms and delaying the formation of “fuzz” structure. The results reported here can help us to design a better radiation resistant plasma facing material in the future.

对于核聚变反应堆而言，发现具有高度抗辐射性的等离子体材料（PFM）是一个紧迫的目标。在我们以前的工作中，发现一种由许多钨晶体柱组成的新型PFM（纳米通道钨膜）具有出色的耐辐射性能。在目前的工作中，通过分子动力学模拟和密度泛函理论计算研究了三个顶面为{100}，{110}和{111}取向的钨柱。我们发现，顶表面为{100}取向的钨柱所保留的氦原子少于顶表面为{110}或{111}取向的钨柱。此外，经过高氦通量暴露后，其顶面为{100}取向的钨柱的微观结构变化较小，这表明，纳米通道钨膜可能比散装钨膜更适合于面向等离子体的材料释放氦原子并延迟“绒毛”结构的形成。此处报告的结果可以帮助我们将来设计更好的抗辐射等离子体表面材料。