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  • 1 Universidade de São Paulo Centro de Energia Nuclear na Agricultura Caixa Postal 96 13400-970 Piracicaba Brazil
  • 2 Delft University of Technology Interfaculty Reactor Institute Mekelweg 15 2629 JB Delft The Netherlands
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Abstract  

The effectiveness of a Compton suppression system (CSS) for instrumental neutron activation analysis of plant materials was evaluated. Suppression factors were measured with 137Cs sources. Five certified reference materials were analyzed and the detection limits calculated from both suppressed and unsuppressed spectra were compared. The CSS demonstrated to be useful for lowering the detection limits of ten out of sixteen elements tested, showing a maximum improvement factor of 3.9. The system performance was strongly influenced by the sample composition and also by the measurement conditions, indicating the importance of testing each individual sample type and analytical protocol.