载能氢原子与石墨(001)面碰撞过程中的能量传递行为的分子动力学研究

本文采用分子动力学方法研究了单一载能氢原子与石墨碰撞时氢原子被石墨反射、 吸附和石墨被氢原子穿透的发生系数以及碰撞中的能量传递机理. 研究发现: 与单层石墨相比, 多层石墨之间的长程相互作用增加了氢原子发生反射的能量范围, 尤其当入射能量大于20.0 eV时, 对反射过程的影响很明显; 当氢原子的入射能量大于25.0 eV时, 有一定的概率穿透四层石墨; 当氢原子入射能量高于28.0 eV时, 载能氢原子的能量传递给第二层石墨烯的比传递给第一层石墨烯的多. 这些结果对理解聚变反应中, 碳基材料的化学腐蚀及氚滞留有重要意义.

Molecular dynamics simulation of energy exchanges between single hydrogen and graphite(001)

Molecular dynamics simulation is applied to the investigation of energy exchanges between single hydrogen and graphite (001). In addition to energy transfer efficiency, in this paper we analyse various kinds of possible processes, which are the absorption on the upside graphite surface, reflection, absorption on the downside graphite surface and penetration, during the course of a hydrogen atom bombarding the crystalline graphite containing four graphene sheets. The simulation results show that the interlayer interaction has a big influence on the reflection, especially when the incident energy is larger than 20.0 eV. The reflection coefficient increases evidently compared with that in single graphene sheet case. If the incident hydrogen has a kinetic energy more than 25.0 eV, it can penetrate the four- sheet graphite at some striking locations. When the incident energy is larger than 28.0 eV, the energy transferring to the first graphene sheet is more than to the second graphene sheet. These results will be helpful for understanding the chemical erosion of carbon based materials and the tritium retention occurring in fusion devices.