Context:
A new atomic simulation method for submicrometer scale simulation is developed for the investigation of plasma-wall interaction. Our group has been studying the interaction between carbon divertors and hydrogen plasmas by molecular dynamics (MD) simulation. Although the MD simulation is one of the powerful tools for the investigation of plasma-wall interaction, the problem with computation time limits the size of the simulatable system to nanometer and nanosecond scales. Because polycrystalline graphite materials are employed for the divertor plates in LHD, the influence of the grain boundary on the retention process of tritium is not neglected. To perform simulations with the structure of polycrystalline graphite which include grain boundaries, the simulation in submicrometer scale is necessary. Our group succeeds in performing the simulation in submicrometer scale by combining the MD simulation code with binary collision approximation code called AC∀T.