Molecular dynamics simulation of hyperthermal neutrals generated by energetic ion impact on a metal plate

A hyperthermal neutral beam (HNB) source is one of candidate methods to reduce plasma-induced damage problems. The HNB is generated by vertical collisions between energetic ions and a reflector composed of a tungsten plate. We perform a HNB generation simulation using a molecular dynamics algorithm. The roughness of the reflector surface is experimentally measured and the surface structure is taken into consideration in the simulation. The energy and angular distributions of the HNB are obtained by the simulation and the energy yield of the reflected neutral particles is found to be in good agreement with experimental data.