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Oxyen isotopic measurements on the CAMECA
NanoSIMS 50
Slodzian G., Hillion F., Stadermann F. J., and Horreard
F. (2003) Applied Surface Science, 203-204, p. 798 -
801.
doi:10.1016/S0169-4332(02)00826-7
ABSTRACT
The CAMECA NanoSIMS 50 has been designed to provide for
parallel detection along a focal plane over a large mass
range but spacing between adjacent mass lines makes it
necessary to use miniature EMs (electron multipliers). A new
version of a miniature EM, designed to reduce aging effects,
has been tested. Means to characterize aging effects are
presented. Data are interpreted by simulations with a simple
model. Consequences of aging on isotopic measurements in a
parallel detection context are examined in the special case
of oxygen. Measurements of the most abundant isotope with a
Faraday cup (FC) and weak isotopes with EMs are reported.
Advantages of FC are emphasized: no dead time correction and
no quasi-simultaneous arrivals to account for in a situation
where high collection efficiencies (8% for O- for
instance) leads to large corrections.
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