Charge exchange in low energy D + scattering from Mo(111)

Abstract

Energy spectra of deuterium positive ions backscattered from clean and oxygen-saturated Mo(111) surfaces are reported with use of D + and neutral D 0 beams with energies below 1 keV. The D + spectrum from the clean Mo(111) surface shows a clear peak corresponding to Mo with very low background intensity. The spectral peak is far smaller in intensity than that for He + scattering and exhibits characteristics of surface scattering of D + ions surviving neutralization on their incoming and outgoing trajectories. The background increases with increase of the oxygen exposure and is caused by reionization of neutral D 0 scattered after significant penetration into the solid, which is confirmed on the basis of the experiments on ionization of the incident D 0 beam.