Recent ORNL measurements of chemical sputtering of ATJ graphite by slow atomic and molecular D ions

We describe here an ORNL Physics Division research activity whose focus is the investigation of chemical sputtering of graphite by atomic and molecular D ions at very low energies that have so far been unexplored. Our initial experimental approach is based on the use of a quadrupole mass spectrometer (QMS) which samples the partial pressure of selected mass species produced in a scattering chamber when the incident ion beam strikes a graphite sample. While most of the ORNL results obtained to date are for D-2(+) ions incident on ATJ graphite, preliminary results are shown for D+ projectiles incident at energies down to 10 eVD(-1), and for D-3(+) ions incident at 10 and 4.5 eVD(-1). The possibility of obtaining complementary information using a time-of-flight approach is discussed as well.