Oxygen determination in metal foils using backscattering spectrometry

Backscattering spectrometry employing 4 MeV proton beam has been used to nondestructively measure the oxygen concentration in holmium, thulium and thorium metal foils. Such foils are used as targets for nuclear physics experiments. Significant amount of oxygen was found in these metallic targets due to their oxidation by atmospheric oxygen. Tungsten oxide was used as a standard to determine the scattering cross-section of 4 MeV protons by oxygen.