Field Emission-Electron Probe Micro Analyzer (FE-EPMA)

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In this proposal, we ask for support for the acquisition of a Field-Emission Electron Probe Micro Analyzer (FE-EPMA), which will be configured with 5 wavelength dispersive spectrometers and mainly L-type (larger) Bragg-crystals that will offer the best possible configuration for the user groups involved in this proposal. It will be further equipped with a panchromatic Cathodoluminescence, Secondary- and Backscattered Electron detectors and an Energy dispersive X-Ray-Detector (EDS). For the past 50 years EPMA-Analysis was an important collar of the research at the Institute of Geosciences at Mainz University and it was intensively used by a large number of users from many workgroups. This led to many important developments for the microprobe analysis community, as, for instance, the development of the “flank-method” for the determination of the oxidation state of iron in garnet or the development of the “point-logger” system, that is now a common tool in most laboratories around the world. Over the past five decades the Institute of Geosciences was receiving funds for the purchase of three Electron Microprobes, one of which was applied jointly with the Max Planck-Institute of Chemistry. The technical innovations of the last years led the development of reliable Schottky emitter microprobes that are shifting boundaries and help us to increase the fields of application. The improved minimum excitation volume offers a much wider range of capabilities. For example, the fields of experimental Petrology and Volcanology have become important areas of research and they would massively profit from the better spatial resolution of the FE-EPMA, as run products from high pressure experiments are often rather small in dimension and can be represented by zoned phases and tiny textural patterns. The better spatial resolution will also help to improve the capabilities for the measurement of mineral intergrowths in nano-composite materials or growth lamella in carbonate organisms that are used for paleo-climate reconstructions.