The penetration and trapping processes of He +, Ne +, and Ar + ions into a graphite (0001) surface is investigated as a function of impact energy between 10 and 500 eV using the low energy ion surface reactor. The interlayer trapping efficiency increases rapidly in the region 10–100 eV, with a threshold appearing at circa 10 eV for all species. At higher energies the efficiency of He + rises continuously with increasing energy, while those of Ne + and Ar + stay near constant.