Isotope ratio determination in microgram levels of osmium by deuteron activation analysis

The feasibility of determining isotope ratios in very small samples of osmium by deuteron activation in the Livermore Tandem Van de Graaf accelerator was demonstrated. The method involves determination of cross-section ratios by using several osmium isotope mixtures carefully prepared from electromagnetically enriched osmium isotopes. The accuracy of this method was checked by a determination of the isotope ratios in naturally-occurring osmium. The analysis demonstrated that an osmium specimen removed from a sample of commercial grade perrhenic acid contained only 0.4% natural osmium, the rest being radiogenic sup(187)Os. (author)