This award will support research aimed at improving the level of accuracy attainable in the quantitative analysis of elements via the electron microprobe. The electron microprobe is a very widely used instrument capable of chemically analyzing for major, minor and trace elements in solid samples with a spatial resolution of one micrometer on polished sample surfaces. The analytical method for determining the concentration of elements depends on the generation of characteristic X-radiation from atoms near the surface due to collisions with a finely focused beam of electrons. The complicated interactions of electrons and photons that determine the intensity of the emerging X-radiation are the key to correcting raw intensity data into accurate quantitative analyses. The staff of the electron microprobe laboratory in the Department of Geological and Planetary Sciences at Caltech, under the direction of the Principal Investigator, have extensive experience the electron microprobe technique and its application to the quantitative analysis of geological samples. This project will produce improvements in the procedures for quantitative analysis that will be disseminated throughout the interested scientific research
