  We used a molecular dynamics simulation with the modified Brenner reactive
empirical bond order potential to investigate the erosion of a graphite surface
due to the incidence of hydrogen, deuterium, and tritium atoms. Incident
particles cause pressure on the graphite surface, and the chemical bond between
graphene layers then generates heat to erode the graphite surface. We evaluated
the speed of surface destruction by calculating the pseudo-radial distribution
function. The speed of surface destruction due to incident hydrogen isotopes
was higher than that due to hydrogen atoms. The surface destruction increased
exponentially and its decay time constant was a power function of the incident
energy. We measured the erosion yield, which indicated a steady state for the
graphite erosion. The erosion yield flux in the steady state increased linearly
with the incident energy. The erosion yield flux was almost independent of the
type of incident particle, and the erosion yield start time was smaller for
hydrogen isotopes than for hydrogen atoms.
