Impurity measurements of the 28Si crystal used for the determination of the Avogadro constant are essential to prevent biased results or under-estimated uncertainties. A review of the existing data confirmed the high-purity of silicon with respect to a large number of elements. In order to obtain a direct evidence of purity, we developed a relative analytical method based on neutron activation. As a preliminary test, this method was applied to a sample of the Avogadro natural silicon crystal WASO 04. The investigation concerned twenty-nine elements. The mass fraction of Au was quantified to be (1.03 ± 0.18) X 10-12. For the remaining twenty-eight elements, the mass fractions were below the detection limits, which ranged between 1 X 10-12 and 1 X 10-5
Elemental characterization of the Avogadro silicon crystal WASO04 by neutron activation analysis
GIORDANI, LAURA FRANCA;ODDONE, MASSIMO
2012-01-01
Abstract
Impurity measurements of the 28Si crystal used for the determination of the Avogadro constant are essential to prevent biased results or under-estimated uncertainties. A review of the existing data confirmed the high-purity of silicon with respect to a large number of elements. In order to obtain a direct evidence of purity, we developed a relative analytical method based on neutron activation. As a preliminary test, this method was applied to a sample of the Avogadro natural silicon crystal WASO 04. The investigation concerned twenty-nine elements. The mass fraction of Au was quantified to be (1.03 ± 0.18) X 10-12. For the remaining twenty-eight elements, the mass fractions were below the detection limits, which ranged between 1 X 10-12 and 1 X 10-5I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
