The Electron Microprobe, obtained
through an NSF Instrumentation Grant to Susan Swapp and
Jimm Myers, is housed in the Department of Geology & Geophysics
at the University of Wyoming.
This instrument is optimized for
quantitative, non-destructive chemical analysis of solid materials.
Elements present in concentrations of at least 0.10 wt. % can usually be quantified to
within ±1%
of the measured abundance, and elements present in smaller concentrations can be measured
with
somewhat less precision. Any number of elements can be included in an analysis.
This instrument is
also capable of high-precision x-ray mapping of spatial variations in chemical
compositions. Both Energy
Dispersive Spectroscopy (EDS) and Wavelength Dispersive Spectroscopy (WDS) mapping are
available,
depending on your requirements.
Our instrument is a JEOL JXA-8900 Electron Microprobe
with 5 fully automated crystal spectrometers, a
fully integrated solid state x-ray detector, backscattered and secondary electron
detectors capable of "real-time"
imaging, fully automated sample stage capable of accomodating a wide variety of sample
sizes and shapes
(up to 6 standard petrographic thin sections), and also includes an HP700i series
workstation and peripherals
for controlling data acquisition and data processing.
For optimal results, samples should be stable in a vacuum
of 10-6 torr, suitable for polishing
to 1 micron
smoothness, include no more than one element of atomic number less than 5, and have
individual particles at
least 5 microns in diameter. Smaller particles, unpolished samples, and samples with
several light elements
can be analyzed, but require special procedures; ask us about YOUR samples.
