Magnus Hedberg oral presentation (FN2-Tue1-1-1)
Latest improvements in isotopic uranium particle analysis by LG-SIMS for nuclear safeguards purposes
1 European Commission, Hermann-von-Helmholtz-Platz 1, 76125 Karlsruhe, Germany
2 CAMECA, 29 quai des Grésillons, 92622 Gennevilliers Cedex, France
It has been demonstrated that Large Geometry Secondary Ion Mass Spectrometry (LG-SIMS) can be used efficiently to search for individual uranium particles among a large matrix of other particles by performing automated sample screening measurements. These screening measurements are typically followed by more precise and accurate micro beam measurements of both the major and minor uranium isotopes on individual particles. The quality of this work is essential when analysing uranium aerosol particles collected in dust samples from nuclear facilities in the search for undeclared nuclear activities.
This paper describes the latest developments that have been undertaken to enhance the detection limits and to improve the uranium isotope measurement accuracy and precision. It includes improvements in the analytical protocol as well as in the instrument acquisition software and data reduction method. Recent useful yield measurements have been performed on uranium mono dispersed particles using different primary bombardment conditions to compare to previously obtained data. Comparison of uranium isotope measurements when using pyrolytical graphite or silica planchets as a sample substrate will also be presented.