TY - JOUR
T1 - Variations of isotopic discrimination in secondary ion mass spectrometry
AU - Jull, A. J.T.
N1 - Funding Information:
The author is grateful to the Max-Planck-Gesellschaft for a fellowship, to Prof_ F. Begemann for the opportunity to work on the Mainz ion micro-pro be, and to S. Specht for invaluable technical assistance. Advice and useful discussions with these and other colleagues in Mainz are dso appreciated.
PY - 1982/1
Y1 - 1982/1
N2 - Isotopic discrimination in a Cameca IMS-3f ion microprobe has been measured as a function of mass, and of primary and secondary ion energy. Discrimination factors were determined for a series of elements (Pb, Mo, Cu, Ni, Cr, Ti and Si) as metallic targets, using an O2+ primary beam. The results show a trend of isotope ratio, and by inference of the fraction of atoms ionized, proportional to M-0.75. Energy-range selection was used to identify a dependence of the measured isotope ratios on the secondary ion energy, favoring the lighter isotopes, ions of lower energy being more fractionated. A small variation with primary ion energy from 0.5 to 13 ke V was also observed fractionation increasing with decreasing primary beam energy. These effects, together with those due to possible instrumental discrimination, must be taken into account for a complete understanding of isotopic measurements obtained by secondary ion mass spectrometry.
AB - Isotopic discrimination in a Cameca IMS-3f ion microprobe has been measured as a function of mass, and of primary and secondary ion energy. Discrimination factors were determined for a series of elements (Pb, Mo, Cu, Ni, Cr, Ti and Si) as metallic targets, using an O2+ primary beam. The results show a trend of isotope ratio, and by inference of the fraction of atoms ionized, proportional to M-0.75. Energy-range selection was used to identify a dependence of the measured isotope ratios on the secondary ion energy, favoring the lighter isotopes, ions of lower energy being more fractionated. A small variation with primary ion energy from 0.5 to 13 ke V was also observed fractionation increasing with decreasing primary beam energy. These effects, together with those due to possible instrumental discrimination, must be taken into account for a complete understanding of isotopic measurements obtained by secondary ion mass spectrometry.
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U2 - 10.1016/0020-7381(82)85030-4
DO - 10.1016/0020-7381(82)85030-4
M3 - Article
AN - SCOPUS:30844435462
SN - 0020-7381
VL - 41
SP - 135
EP - 141
JO - International Journal of Mass Spectrometry and Ion Physics
JF - International Journal of Mass Spectrometry and Ion Physics
IS - 3
ER -