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A Simple, Extremely Stable Single-Tube Liquid Scintillation System for Radiocarbon Dating

Published online by Cambridge University Press:  18 July 2016

Pall Theodórsson
Pall Theodórsson*
Affiliation:
Science Institute, University of Iceland, Dunhaga 3, IS-107 Reykjavík, Iceland. Email: pth@raunvis.hi.is
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Abstract

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This paper describes a simple and compact liquid scintillation radiocarbon dating system, ICELS, and demonstrates its long-term stability and reproducibility to a precision level rarely presented before, better than 0.04% (3 14C yr). Inexpensive systems of this kind may, in the future, help to meet increasing demand for high precision (±16 to ±20 14C yr) and strict quality control. ICELS comprises a compact detector unit, where a 3-mL dome-shaped vial, with an optimal light reflector, sits on the top of a vertical 30-mm photomultiplier tube. Sample changing is manual. The high voltage is set at the balance point for each sample, securing maximal counting stability. The quench correction method used (spectrum restoration) corrects with 0.04% precision for all parameters that can normally shift the 14C spectrum. For 3 mL of benzene at 71% 14C counting efficiency (recent carbon 23 cpm), the background is 1.72 cpm behind a 5-cm-thick shield of lead (27 kg) and 1.53 cpm behind 10 cm of lead. The background count rate corrected for atmospheric pressure variations was completely stable over 47- and 57-d testing periods for the 2 systems.

Type
Articles
Information
Radiocarbon , Volume 47 , Issue 1 , 2005 , pp. 89 - 97
Copyright
Copyright © 2005 by the Arizona Board of Regents on behalf of the University of Arizona 

References

Einarsson, S. 1992. Evaluation of a prototype low-level liquid scintillation multisample counter. Radiocarbon 34(3):366–73.Google Scholar
Einarsson, S, Theodórsson, P. 1995. Stability of a new, multichannel, low-level liquid scintillation counter system, Kvartett. Radiocarbon 37(2):727–36.Google Scholar
Gupta, SK, Polach, HA. 1985. Radiocarbon Dating Practices at ANU. Canberra: Australian National University. 94 p.Google Scholar
Kojola, H, Polach, H, Nurmi, J, Oikari, T, Soini, E. 1984. High-resolution low-level liquid scintillation beta-spectrometer. International Journal of Applied Radiation and Isotopes 35(10):949–52.Google Scholar
McCormac, FG. 1992. Liquid scintillation counter characterization, optimization and benzene purity correction. Radiocarbon 34(1):37–45.Google Scholar
Noakes, JE, Valenta, RJ. 1989. Low background liquid scintillation counting using an active sample holder and pulse discrimination electronics. Radiocarbon 31(3):332–41.Google Scholar
Pearson, GW. 1979. Precise 14C measurement by liquid scintillation counting. Radiocarbon 21(1):1–21.Google Scholar
Pearson, GW. 1983. The development of high-precision 14C measurements and its application to archaeological time scale problems [PhD dissertation]. Belfast: Queen's University Belfast.Google Scholar
Theodórsson, P. 1998. Norse settlement of Iceland—close to AD 700? Norwegian Archaeological Review 31: 29–38.Google Scholar
Theodórsson, P, Ingvarsdottir, S, Gudjonsson, GI. 2003. Balanced window in 14C liquid scintillation counting. Radiocarbon 45(1):113–22.CrossRefGoogle Scholar