Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-26T08:52:34.116Z Has data issue: false hasContentIssue false

The Statistics of Low-Level Counting Using the New Generation of Packard Liquid Scintillation Counters

Published online by Cambridge University Press:  18 July 2016

G. T. Cook
Affiliation:
Scottish Universities Research and Reactor Centre, East Kilbride G75 0QU Scotland
E. M. Scott
Affiliation:
Department of Statistics, University of Glasgow, Glasgow G12 8QW Scotland
E. M. Wright
Affiliation:
Department of Statistics, University of Glasgow, Glasgow G12 8QW Scotland
Robert Anderson
Affiliation:
Scottish Universities Research and Reactor Centre, East Kilbride G75 0QU Scotland
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We consider the suitability of commonly used Poisson counting statistics applied to background count rates measured in the new generation of low-background Packard liquid scintillation spectrometers. We also investigate the stability of these systems over long time intervals. Undetected instability will result in an underestimation of the precision of any result (i.e., the calculated error will be too small), and, in the presence of a systematic source, could lead to inaccurate results. The work described here forms only a small part of a project to investigate the statistical criteria that should be applied to the performance of such counters. The procedures to be discussed here include the Poisson index of dispersion, x and s control charts and the MSSD test for detection of drift. These are illustrated on background count rates derived from the Packard 2260XL and 2000CA/LL.

Type
I. Sample Preparation and Measurement Techniques
Copyright
Copyright © The American Journal of Science 

References

Cox, D. R. and Lewis, P. A. W. 1966 The Statistical Analysis of a Series of Events. London, Methuen Monograph.Google Scholar
Currie, L. A. 1972 The limit of precision in nuclear and analytical chemistry. Nuclear Instruments and Methods 100: 387395.Google Scholar
Hooton, K. A. H. and Parsons, M. L. 1973 Equipment stability in x-ray fluorescence spectrometry and radioactive counting – a statistical approach. Analytical Chemistry 45(13): 22182227.CrossRefGoogle Scholar
Kotz, S., Johnston, N. L. and Read, C. B. 1986 Encyclopedia of Statistical Sciences, Vol. 7. New York, Wiley - Interscience.Google Scholar
Long, A. and Kalin, R. M. 1990 A suggested quality assurance protocol for radiocarbon dating laboratories. In Scott, E. M., Long, A. and Kra, R. S., eds., Proceedings of the International Workshop on Intercomparison of 14C Laboratories. Radiocarbon 32(3): 329334.Google Scholar
Noakes, J. E. and Valenta, R. J. 1989 Low background liquid scintillation counting using an active sample holder and pulse discrimination electronics. In Long, A. and Kra, R. S., eds., Proceedings of the 13th International 14C Conference. Radiocarbon 31(3): 332341.Google Scholar
Pearson, G. W. 1979 Precise 14C measurements by liquid scintillation counting. Radiocarbon 21(1): 121.Google Scholar
Ryan, T. P. 1989 Statistical Methods for Quality Improvement. New York, John Wiley & Sons Inc. Google Scholar
Switsur, R. 1990a A consideration of some basic ideas for quality assurance in radiocarbon dating. In Scott, E. M., Long, A. and Kra, R. S., eds., Proceedings of the International Workshop on Intercomparison of 14C Laboratories. Radiocarbon 32(3): 342346.Google Scholar
Switsur, R. 1990b Statistical quality control graphs in radiocarbon dating. In Scott, E. M., Long, A. and Kra, R. S., eds., Proceedings of the International Workshop on Intercomparison of 14C Laboratories. Radiocarbon 32(3): 347354.Google Scholar