k0-Neutron Activation Analysis at CDTN, Brazil: 27 years of history, development and main achievements

Neutron Activation Analysis is an analytical technique to assay the chemical elemental composition in samples of various matrices. It has been applied by the Laboratory for Neutron Activation Analysis, located at Nuclear Technology Development Centre/Brazilian Commission for Nuclear Energy, CDTN/CNEN, since the starting up of the TRIGA Mark I IPR-R1 reactor in 1960. Among the methods of this technique, the k 0 -method, which was established at CDTN in 1995 and re-established and improved in 2003 as k 0 -standardized method, is the most efficient multielemental concentration determination. The results of participation in proficiency testings indicated which unsatisfactory data produced by k 0 -method should be improved over the years. This paper is about the history of the development of k 0 -method at the laboratory and the main achievements.