The study of sputtering by concentration modulated absorption spectroscopy and the study of internal energy effects on collision induced decomposition mass spectrometry

• Main Author: Naylor, J. C.
• Published: Swansea University 1999
• Subjects: 530.417
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.638299

The measurement of the absolute concentration of sputtered neutrals from a metal Li surface and polycrystalline NaC1 target has been achieved using the technique of concentration modulated absorption spectroscopy. The dependence of the amount sputtered on the target temperature, ion energy and target density has been investigated. The atomic density of the plume has been mapped in two dimensions under varying sputtering conditions. Utilising a previous theory describing a radial sputter distribution function the experiments have yielded values for the sputter yield of lithium and sodium. The profiling of sputtered neutrals across a planar glow discharge under varying cell conditions and discharge gases has been achieved using the laser spectroscopic technique. These experiments show that the sticking coefficient, α, of Li atoms on Li metal is non-unity. The experiments have been fitted using a Monte-Carlo model to generate values of α. An analytical model has also been developed to fit the experimental data. The model yields useful physical parameters concerning the plasma. This includes sticking coefficient data. The model has been compared with the computer-based method. High-energy collision induced decomposition mass spectrometry has been to investigate the possible effect of the internal energy of the precursor ion on the appearance of the spectra. Deuterated ethanol and the protonated deuterium counterpart were specifically produced in the ion source isomerically pure and to eliminate the presence of isotope scrambling. The experiments show that the spectra do vary significantly depending on the reaction conditions of temperature and pressure under which the protonated ethanol or the deuterated equivalent is produced.