Scanning Electron Microscope Upgrade to Field Emission with Xray Spectrometry

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Oregon State University (OSU) asks assistance to upgrade a thermionic scanning electron microscope (SEM) to a field emission scanning electron microscope (FESEM) with an integrated x-ray energy spectrometer (XES). This system will replace a 1978 AmRay 1000A SEM acquired in used condition in 1981 and a Kevex 7000 X-ray spectrometer purchased in 1982. OSU has taken over 30,000 micrographs and logged in excess of 6000 beam hours with the now obsolete SEM system. In 1993-94, 165 campus researchers from 24 departments in nine colleges used the Electron Microscope Facility at OSU; the facility is managed by the Department of Botany and Plant Pathology and provides the only access on the OSU Campus to an instrument of this type. Diverse research programs at OSU would benefit from the FESEM/XES which has improved resolution, broader versatility, and significant improvement of capabilities over the thermionic SEM recently co-funded by NSF (BIR-9420049). FESEM offers low voltage high resolution of non-coated biological specimens at 4-5 nm versus 150 nm for thermionic SEM which always requires destructive specimen coating. High voltage allows resolution c 1.5 nm versus 15 nm for a new thermionic SEM and 70 nm for the current system. FESEM/XES allows determination of element compositions in soils and mineral cycles including the new capability to identify nitrogen, boron, oxygen and fluorine and much better resolution of sodium. The biologists at OSU would be primary beneficiaries of this instrument as they constitute 7075% of the SEM use; the remaining 25-30% will be utilized by physical science, associated materials science and engineering programs. Major biological users include Dr. Philip Brownell's research on sensory neurobiology of arthropods which focuses on cuticular sense organs and the correlation of fine structure with sensory function. Dr. Elaine Ingham would utilize the FESEM/XES to determine change in structure and mineral composition of soil under conditi ons of global climate change. Dr. Terri Lomax's research centers on understanding the regulation of plant growth and development at the level of cellular responses to hormonal and environmental signals. Dr. Robert Mason studies the reproductive biology and chemical ecology of reptiles. Dr. Michael Nesson focuses on iron biomineralization and the role of biologically synthesized magnetic minerals. Dr. Barbara Taylor's program investigates intercellular communication between muscles and their innervating nerves during adult development of fruit flies. Most of these researchers have or have had significant NSF funding for their programs. In addition, this SEM/XES system would benefit other major user groups in chemical engineering, geosciences and materials sciences. Representative research programs are described for each of these areas. It will also assist in attracting faculty and students to OSU, contribute to undergraduate and graduate student training, and is essential to many other of OSU's basic and applied research programs in: x biochemistry, botany, chemistry, entomology, geology, microbiology, physics, plant pathology, and zoology; x air, water, and soil ecology, pollution, and resource development and conservation; x forest pathology, productivity, and development and performance of wood products; x foods and nutrition; x engineering, advanced metallic, ceramic, glass, and polymeric materials; development, failure analysis, and tribology.