Oxygen and Titanium Sputtering Yields as Determined by Laser Fluorescence and Auger Electron Spectroscopy for Monolayer Oxygen Coverage of Polycrystalline Ti

摘要

The presence of an oxide layer can strongly influence the charge-state of species ejected from ion-bombarded metal surfaces, as well as the total sputtering yield. These quantities directly affect the influx of metallic impurities from the wall region into the plasmas of fusion devices. Surface coverage can also modify the distribution of sputtered atoms among electronic states and thus the apparent impurity density detected by the laser fluorescence spectroscopy (LFS) technique. The measurements reported here provide LFS data on number density and electronic state populations for the species Ti and Ti exp + as a function of surface oxygen coverage in a laboratory apparatus providing for direct monitoring by Auger analysis. (ERA citation 08:022699)