INTO THE MICRO-WORLD: 10 YEARS OF UNDERGRADUATE EPMA FOR TEACHING AND RESEARCH

In 2010, Concord University established an electron microprobe (EPMA) laboratory, an unusual step for a primarily undergraduate, liberal-arts university. Operating major research instrumentation has advantages, and the laboratory has been a key tool in supporting innovations in undergraduate teaching and research for the past decade.

The core instrument is an upgraded ARL SEMQ electron microprobe located in a dedicated climate-controlled laboratory. In its current configuration, the microprobe is equipped with 6 WDS spectrometers, a modern 30mm² silicon drift detector EDS spectrometer with light element capability, a large high-sensitivity backscattered electron detector, digital image acquisition, re-designed sample positioning, and a vibration isolation platform. Beam current is well-regulated with all-day drift typically under 0.5%. Automation and data acquisition are provided by Probe for EPMA and Bruker Esprit running on current PC hardware. The instrument is supplemented by a sample preparation laboratory, Horiba XGT-5200 micro-XRF, petrographic microscopes, high-resolution scanner for full thin section scans, and a collection of more than three hundred micro-analytical reference materials for calibration and quality control. Major and trace-element analysis, electron imaging, and EDS x-ray mapping are conducted routinely with excellent results. Development of these capabilities has been possible through numerous small grants, lab revenues, and institutional funds.

The instrument affords outstanding opportunities for our students who have taken to the available capabilities with enthusiasm. The microprobe is integrated into the curriculum at all levels and is used in multiple disciplines, including geology, chemistry, and physics. It is used regularly in introductory level, general education science courses, and it is key to supporting an innovative 5-course multi-year research-embedded undergraduate curriculum. The instrument also supports independent research by students, faculty, and visitors including e.g. volcanic ash (including fine distal cryptotephras), igneous and metamorphic petrology, and frictional melts and microstructures. All of this demonstrates that major instrumentation can be truly viable with a large impact at undergraduate institutions.