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The NEC accelerator produces beams of
protons or alpha particles at energies up
to 3.4 MeV for protons or 5 MeV
for alpha particles at currents up to
100 nA. Standard techniques, including
RBS (Rutherford Backscattering), PIXE
(particle-induced X-ray emission), and NRA
(nuclear reaction analysis), are routinely
performed. RBS provides detailed
composition and thickness information from
the top few micrometers of a sample, and is
especially sensitive for heavy films on
light substrates. PIXE provides both major
element and trace element chemical analysis
non-destructively and is also sensitive to
heavy elements in a light matrix; minimum
detectability is 100 ppm
concentrations in most cases. It is also
possible to bring the beam out of the
vacuum system to perform PIXE on large,
unusually shaped solids (such as Egyptian
artifacts from the Middle Kingdom belonging
to the Cleveland Museum of Art!) or gaseous
samples. NRA is used to detect and measure
light elements such as boron or fluorine,
or for isotopically labeled samples, such
as oxides enriched in 18O.
This material is based upon
work supported by the National Science
Foundation under Grant No. DMR94-08720. Any
opinions, findings, and conclusions or
recommendations expressed in this material
are those of the author(s) and do not
necessarily reflect the views of the
National Science Foundation.
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