• Accelerator Mass Spectrometry: From Nuclear Physics to Dating

      Kutschera, Walter (American Journal of Science, 1983-01-01)
    • Tandem Accelerator Measurements of 10Be Deposition Rates

      Nelson, D. E.; Korteling, R. G.; Southon, J. R.; Vogel, J. S.; Nowikow, I.; Ku, T. L.; Kusakabe, Masashi; Reyss, J. L. (American Journal of Science, 1983-01-01)
      A Tandem Van de Graaff accelerator has been modified for use in the direct measurement of natural abundances of 10Be and 14C. A description of the system is given and some 10Be results on oceanographic samples are discussed.
    • Technological Advances in the University of Washington Accelerator Mass Spectrometry System

      Farwell, G. W.; Grootes, P. M.; Leach, D. D.; Schmidt, F. H. (American Journal of Science, 1983-01-01)
      During the past year we have continued to work toward greater stability and flexibility in nearly all elements of our accelerator mass spectrometry (AMS) system, which is based upon an FN tandem Van de Graaff accelerator, and have carried out measurements of 14C/12C and 10Be/9Be isotopic abundance ratios in natural samples. The principal recent developments and improvements in the accelerator system and in our sample preparation techniques for carbon and beryllium are discussed, and the results of a study of 10Be cross-contamination of beryllium samples in the sputter ion source are presented.
    • Temporal 10Be Variations in Ice

      Beer, Jürg; Andree, Michael; Oeschger, Hans; Stauffer, Bernhard; Balzer, Richard; Bonani, Georges; Stoller, Christian; Suter, Martin; Wölfli, Willy; Finkel, Robert C. (American Journal of Science, 1983-01-01)
    • The Radon Problem in 14C Dating

      Nydal, Reidar (American Journal of Science, 1983-01-01)
      Due to traces of radium and uranium in most 14C samples, radon appears as a radioactive contamination in the CO2 prepared by combustion. This contamination must be removed by an active purification prodecure or by storing the CO2 prior to measurement. No effective electronic discrimination against radon and its daughter elements can be performed. The necessary storage time until radon has decayed varies widely, especially for marine shells. The latter material, collected from Norway and Svalbard, has been a main object for the present investigation. In a few cases, a measureable amount of radon may be left even after eight weeks. The behavior of radon and its daughter elements in a CO2 proportional counter has been studied.