Nondestructive assay (NDA) of /sup 233/U in quantities up to 15 grams containing 7 ppM /sup 232/U age 2 years was investigated with a random driver. A passive singles counting technique showed a reproducibility within 0.2% at the 95% confidence level. This technique would be applicable throughout a process in which all of the /sup 233/U had the same /sup 232/U content at the same age. Where the /sup 232/U content varies, determination of /sup 233/U fissile content would require active NDA. Active coincidence counting utilizing a /sup 238/Pu, Li neutron source and a plastic scintillator detector system showed a reproducibility limit within 15% at the 95% confidence limit. The active technique was found to be very dependent on the detector system resolving time in order to make proper random coincidence corrections associated with the high gamma activity from the /sup 232/U decay chain.

Techniques for conditioning of Ta filaments for improved bonding and emission with a Ta metal powder-Ta/sub 2/O/sub 5/ mixture are described. A porous Ta metal layer is deposited which restricts sample to the filament. Metal- oxide ion emission is enhanced with additional Ta/sub 2/O/sub 5/ to the porous layer. Reduction of fractionation through action of liquid Ta/sub 2/O/sub 5/ is discussed in particular for Sr+ emission. Use of conditioned filaments for rapid U concentration analysis with a single-filament mass spectrometer is emphasized. (auth)

The specific activity of 94Nb has been determined by counting and mass-analysing two samples of reactor-irradiated niobium. The β-half-life of 94Nb is (2·03 ± 0·16) × 104 years. 94Nb emits 703 ± 5 keV and 874 ± 5 keV γ-rays with 100 per cent abundance; the 1580 keV crossover γ-ray has an abundance of <0·05 per cent. The K electron capture branching of 94Nb is < 6 per cent of the β-decay. The γ-spectrum of 6·6 min 94mNb has also been studied.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTUranium Determination by Isotope Dilution TechniquePaul. Goris, W. E. Duffy, and F. H. TingeyCite this: Anal. Chem. 1957, 29, 11, 1590–1592Publication Date (Print):November 1, 1957Publication History Published online1 May 2002Published inissue 1 November 1957https://pubs.acs.org/doi/10.1021/ac60131a006https://doi.org/10.1021/ac60131a006research-articleACS PublicationsRequest reuse permissionsArticle Views115Altmetric-Citations10LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts