Determination of oxygen by activation analysis with 14 MeV fast neutrons

A method for the determination of oxygen in steel and other metals by the 16O (n, p) 16N reaction with 14MeV neutrons has been investigated. Parameters such as instrumental conditions, sample size, and interferences from other elements can be recognized and their effects are evaluated and experimentally controlled.The sample size is important to obtain a good precision and accuracy. For the industrial routine analysis a preference is given to cylindrical samples of diameter 12·5mm and thickness 10mm. In order to ensure a reliable pneumatic transport and minimize the error in counting, tolerances on the size must be kept within ± 0·2mm as strictly as possible.Interferences by B and F on the oxygen analysis are experimentally investigated. B and F of 0·1% correspond to oxygen of 70 and 420ppm, respectively.The long-term coefficient of variation for analysis of a given sample over a period of 10 days is 4 to 10%.The accuracy of this method is checked by comparison of the results with those of the vacuum fusion method. The agreement of the results obtained by the two methods is satisfactory.The determination of oxygen in various powder samples such as acid insoluble residue in steel and iron powder is also demonstrated with satisfactory results.