title: Fast and accurate dating of nuclear events using La-140/Ba-140 isotopic activity ratio.
abstract: This study reports on a fast and accurate assessment of zero time of certain nuclear events using La-140/Ba-140 isotopic activity ratio. For a non-steady nuclear fission reaction, the dating is not possible. For the hypothesis of a nuclear explosion and for a release from a steady state nuclear fission reaction the zero-times will differ. This assessment is fast, because we propose some constants that can be used directly for the calculation of zero time and its upper and lower age limits. The assessment is accurate because of the calculation of zero time using a mathematical method, namely the weighted least-squares method, to evaluate an average value of the age of a nuclear event. This was done using two databases that exhibit differences between the values of some nuclear parameters. As an example, the calculation method is applied for the detection of radionuclides La-140 and Ba-140 in May 2010 at the radionuclides station JPP37 (Okinawa Island, Japan).
authors.affiliation: Université de Ouagadougou (UO), BP 7021 Ouagadougou, Burkina Faso. Electronic address: fairlir@yahoo.fr.
authors.forename: Kassoum
authors.initials: K
authors.lastname: Yamba
authors.affiliation: Centre National de Recherche Scientifique et Technologique (CNRST), Ouagadougou, Burkina Faso.
authors.forename: Oumar
authors.initials: O
authors.lastname: Sanogo
authors.affiliation: Comprehensive nuclear Test-Ban Treaty Organization (CTBTO), Vienna, Austria.
authors.forename: Martin B
authors.initials: MB
authors.lastname: Kalinowski
authors.affiliation: Comprehensive nuclear Test-Ban Treaty Organization (CTBTO), Vienna, Austria.
authors.forename: Mika
authors.initials: M
authors.lastname: Nikkinen
authors.affiliation: Université de Ouagadougou (UO), BP 7021 Ouagadougou, Burkina Faso.
authors.forename: Jean
authors.initials: J
authors.lastname: Koulidiati
keywords: Ba-140; CTBTO; Isotopic activity ratio; La-140; Zero time