This grant provides support to upgrade the electron microprobe laboratory at Northern Arizona University. The instrument, an ETEC Autoprobe dating from the 1970's, will be outfitted with modern detector electronics and a video optical system. At present, the instrument is equipped with original ETEC preamplifiers, pulse-height analyzers, detector high-voltage power supplies, and rate meters. All are at least 20 years old and have become unstable over the course of operation. Newer components are not available because ETEC is no longer in business. The old components will be replaced with modern off-the-shelf components and the electronic feed-throughs will be modified to accept these new components. These upgrades will indefinitely extend the lifetime of the instrument, increase instrument stability, and allow for easy repair. The existing light optical microscope will be supplemented with a video system consisting of a video camera, monitor, image-capture board, and PC. This upgrade will enhance teaching and training capabilities of the machine appreciably, allowing a number of people to simultaneously observe analytical operations. The image-capture system will allow accurate real-time records of the locations of analyzed points to be generated. The lab serves the northern Arizona and southern Nevada region and is used by faculty from the Departments of Anthropology and Geology at Northern Arizona University, the Department of Geology at the University of Nevada, Las Vegas, and researchers from the U.S. Geological Survey Flagstaff Field Office, and the Navajo Nation Archaeology Department. The lab supports varied research in igneous and metamorphic petrology, archaeology, and anthropology. ***
