Materials characterization using ion bombardment and multiphoton resonance ionization

The combination of energetic ion bombardment with multiphoton resonance ionization (MPRI) spectroscopy has proven to be an important advancement in surface science. The goal of this project is continuing the development of MPRI of desorbed neutrals as a surface analytical tool. The method for accomplishing this is a detailed examination of the factors which govern a measurement and the implementation of the optimum experimental approach. Initially, a review of the progress in laser post-ionization of desorbed neutral particles is presented. This is followed by a description of the newly redesigned instrument, emphasizing detailed characterization of the high current ion source and the reflecting time-of-flight mass spectrometer. Using the new apparatus, the quantitative aspects of the measurement are examined and the fractions of desorbed ions and neutrals are determined using several matrices. The In concentration in a set of silicon wafers is measured, yielding a detection limit of 9 parts-per-trillion. Finally, the prospects for employing this experiment for measuring the half-life of the rare double beta decay of 136Xe to 136Ba are assessed