| 英文摘要: | The acquisition of a new, state-of-the-art electron microprobe at the University of Massachusetts serves to enable numerous NSF funded research projects involving researchers at UMass and the other members of the Five-college community (Smith, Mt. Holyoke, Amherst, and Hampshire colleges), and many other regional and national institutions. This MRI grant supports the acquisition of an instrument that will replace an aging electron probe that was the workhorse micro-analytical tool at UMass for the past 27 years, a significant portion of the 50+ year legacy of electron probe micro-analysis at UMass. Students and researchers have used, and continue to use, the facility for compositional mapping and compositional micro-analysis for research in petrology, geochemistry, climate science, biology, chemistry, materials research, and engineering, and the growing emphasis on high-technology materials will continue to expand this use into exciting new directions in a number of fields of the physical and engineering-related sciences. This grant serves to directly support NSF?s mission to promote the progress of science and advance the national health, prosperity, and welfare as the enabled fundamental research has the potential to greatly enhance our understanding of Earth and planetary processes, processes involving the origin and evolution of life, and in the exploration and development of resources and technology.
The electron probe micro-analyzer (EPMA) provides non-destructive, in-situ analysis of mineral phases on the scale of a micrometer or less by use of a focused electron beam that generates characteristic X-rays from the target sample. The intensity of these X-rays is used to calculate the absolute concentrations of specific elements in the target. Reaction histories and the conditions of formation can be inferred, revealing geologic or other relevant physical/chemical aspects of natural and synthetic systems, everything from the formation of continents to biomineralization architectures (such as crustacean cuticles), to the construction of optical fibers, integrated circuits, or alloys. The new instrument will offer much improved electron beam performance over a higher range of current and voltage, higher resolution sample stage motion, better, cleaner vacuum technology, high counting efficiency spectrometers for improved precision and analytical efficiency, highly improved, more robust electronics for improved reliability and stability, and greatly improved control and analysis software. Current projects supported by NSF include studies of mid and deep-crustal processes, field and experimental studies of magmatic systems from around the world, mineral analysis for spectroscopy and mineralogy; meteoritics, environmental materials analysis, as well as materials testing for researchers from engineering and compositional analysis for soil science. The new microprobe will also play an essential role in a major technique development project at UMass, electron microprobe geochronology. With a new microprobe, the UMass facility will be well positioned to move forward as a regional resource for new development, on-going research, and student training. Many faculty members, and post-docs depend on the UMass electron probe facility, and hundreds of students have interacted with the facility as part of student research, class projects, and/or lab demonstrations. In addition, many outside researchers who visit the laboratory are from non-PhD granting institutions and many bring undergraduate students to participate in the analytical work. The UMass Microprobe Facility has played a major role in training future analysts including practical and theoretical courses at UMass and training of a large number of post-doctoral fellows, graduate students, and undergraduate students. The PIs have run numerous tours, lab demonstrations, workshops, and lectures for UMass, Five-college, and outside college classes, for K-12 classes, for community groups, and for the general public. These activities inspire interest in both science-oriented and non-science oriented people, and reinforce the message that modern Geoscience is a quantitative, high-tech, very relevant endeavor. |