• Accelerator Mass Spectrometry with Fully Stripped 36Cl Ions

      Haberstock, Günther; Heinzl, Johann; Korschinek, Gunther; Morinaga, Haruhiko; Nolte, Eckehart; Ratzinger, Ulrich; Kato, Kazuo; Wolf, Manfred (American Journal of Science, 1986-01-01)
      A description of accelerator mass spectrometry (AMS) measurements with the long-lived radioisotope 36Cl is given. All measurements were made at the Munich tandem accelerator laboratory. Results are presented for 36Cl measurements in ground waters, in the meteorite Bjurböle, in ice-core samples of the Vernagtferner, Austria, and in granite samples from Hiroshima, Japan, irradiated by the atomic bomb explosion in 1945.
    • Laser Resonance Ionization Mass Spectrometry for Krypton-81 Analysis

      Lehmann, B. E.; Loosli, H. H.; Oeschger, Hans; Rauber, Dominique; Hurst, G. S.; Allman, S. L.; Chen, C. H.; Kramer, S. D.; Thonnard, Norbert; Willis, R. D. (American Journal of Science, 1986-01-01)
      A new laser-based analytical technique is described for isotope selective noble gas atom counting. The method has been used to detect 81Kr atoms in a groundwater sample.
    • Measurement of 10Be and 26Al with a Tandetron Accelerator Mass Spectrometer Facility

      Yiou, Francoise; Raisbeck, Grant M.; Bourles, Dider; Lestringuez, Jacques; Deboffle, Dominique (American Journal of Science, 1986-01-01)
      A description is given of the use of a Tandetron accelerator mass spectrometer system for measuring the isotopes10Be and 26Al.
    • The Chemical Preparation of AgCl for Measuring 36Cl in Polar Ice with Accelerator Mass Spectrometry

      Conard, N. J.; Elmore, David; Kubik, P. W.; Gove, H. E.; Tubbs, L. E.; Chrunyk, B. A.; Wahlen, Martin (American Journal of Science, 1986-01-01)
      A method of chemical separation and purification of chloride from relatively small samples (500 to 2100g) of glacial ice is presented. With this procedure the first successful measurements of pre-bomb levels of 36Cl in Greenland ice have been made. Emphasis is placed on methods of reducing sulfur, which causes interference in the accelerator mass spectrometry, and in maximizing the yield. Data regarding the selection of materials for sample holders and the use of metal powders for extending the lifetime of the sample are also presented.
    • Toward a Thesaurus of Radiocarbon Dating and Related Terms

      Polach, Dilette (American Journal of Science, 1986-01-01)
      The development of a Thesaurus of Radiocarbon Dating and Related Terms was undertaken to provide a basic common vocabulary of terms for the purpose of indexing an Annotated Bibliography of Radiocarbon Dating (1948-68) and form the basis of a language for information storage and retrieval in 14C dating and related term areas. The interdisciplinary nature of 14C dating dictates that selected terms have meanings in the context of archaeology, geology, earth sciences, oceanography, and environmental sciences, to name but a few, as well as chemistry and nuclear instrumentation on which the technique of 14C determinations is based. This paper describes the method used for selection of terms and explains the structure of the proposed thesaurus. A limited edition Draft Thesaurus was distributed to a selected panel of colleagues for critical evaluation.
    • Trends of 13C/12C Ratios in Pinyon Tree Rings of the American Southwest and the Global Carbon Cycle

      Leavitt, S. W.; Long, Austin (American Journal of Science, 1986-01-01)
      An accurate atmospheric 13C/12C chronology can provide important constraints to models of the global carbon cycle. Trees accumulate carbon from atmospheric CO2 into growth rings and offer potential for 13C/12C reconstructions, but results have not been reproducible. This paper presents 5 degree C curves from 5 sites, representing 20 pinyon (Pinus edulis) trees, where cores of 4 trees from each site have been pooled into a composite sample. Isotopic analysis of cellulose in 5-yr ring groups produces curves with a general trend of decreasing 5 degree C after 1800, but with pronounced short-term fluctuations superimposed upon the trend. Evidence indicates the fluctuations are strongly related to moisture availability (drought). A mean curve of the 5 delta-13C chronologies from which the fossil-fuel component is subtracted suggests a substantial biospheric CO2 contribution to the atmosphere since 1800.