This award provides $181,586 in NSF funding over 12 months to acquire three major electron microprobe components; the energy dispersive analytical spectrometer (EDS), the Tracor Northern spectrometer automation system and the PAC X-ray counting electronics which all need replacing on the institution?s EMP. This upgraded instrument will be used for petrologic studies and analyzing archaeological materials. Ultramafic rocks from the Blue Ridge (southern Appalachian Orogen) will be assessed for origin. The PIs will also use the instrument to study fin-grained anhydrites from the Redoubt Volcano, granitic rocks from western North Carolina, crustal melts from South America, hydrous and volatile phases, planetary materials, and metasomatic fluids in the Earth?s mantle. Additionally, the upgrade EMP will be used for understanding mineral composition, zoning and phase proportions. Institutional and outside collaborators will also be analytically-supported. This requested equipment is needed to keep the facility up and running. Historically, the EMP lab has led to approximately 100 research papers, numerous abstracts and more than 30 M.S. theses and Ph.D. dissertations. The EMP facility supports Geology and Chemistry departments at UGA and other geoscience departments in the Southeast. A new initiative outlined in the proposal is to use the facility to support wider participation by students at 4-year institutions in the Southeast who do not have on-campus access to a microprobe facility. The Department of Geology provides a service contract for this instrument and supports a full-time Electron Microprobe Laboratory Coordinator. The technician works with the instrument day-to-day and provides scheduling and training for users.
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The electron microprobe is a critical instrument for characterizing the composition of solid materials with numerous applications in the sciences and the manufacturing industries. The instrument utilizes a tightly focused electron beam to excite X-rays typically from a small area (less than 10 microns diameter) on a thin wafer of a solid material. The wavelengths of the resultant X-rays are determined by the elements in the material, and the intensity of the X-rays are proportional to the abundance of the element in the material. By measuring the intensities of the X-rays generated by the electron beam, the composition of the material can be calculated. For example the instrument can be used to determine if a manufactured metal, such as steel, is chemically homogeneous or the exact composition of a naturally occurring ore of copper. At the University of Georgia (UGA), the JEOL JXA 8600 electron microprobe is a core laboratory facility in the Department of Geology and has been used by our faculty and generations of geology graduate and undergraduate students in their thesis research as well as by faculty and students from other departments at UGA and from neighboring academic institutions. It is the only research electron microprobe in the state of Georgia and only one of a handful in the Southeast. The microprobe was originally purchased in 1988 and the automation software was upgraded (funded by NSF) in 1998. Eventually, a key detector, an energy dispersive spectrometer, used to rapidly identify and measure X-ray intensities failed due to age. Additionally, the electronics associated with wavelength dispersive spectrometers and sample positioning as well as the computerized operating system became obsolete and unstable. The project we are reporting on was funded to replace the obsolete and inoperable components on the microprobe so that it could be used in materials analysis for the next 10-15 years. After evaluating bids from a number of companies, we contracted with an American company, Advanced Microbeam, to supply the necessary components, to install the components and to verify that they were operational. In February, 2012, an engineer from Advanced Microbeam spent 2 weeks at UGA and successfully installed a new EDS detector system, replaced the electronic components that controlled the wavelength dispersive spectrometers, the motors that control spectrometer and sample positioning and the controlling computer and its software. Following installation, the engineer verified that software and mechanical components were operating correctly. The microprobe at UGA has now been updated and is now undergoing final testing. This microprobe will be used in the training and teaching of future generations of geology students at UGA, students from other departments, and students from neighboring institutions. It will also be used in research projects of UGA faculty as well as faculty from other institutions, and is available for industrial applications as needed.
