Developing a single-aliquot protocol for measuring equivalent dose in biogenic carbonates

R. J. Stirling*, G. A. T. Duller, H. M. Roberts

*Awdur cyfatebol y gwaith hwn

Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

17 Dyfyniadau (Scopus)

Crynodeb

Exploiting biogenic carbonates as thermoluminescence dosimeters requires an understanding of trap kinetics and an appropriate sequence with which to measure equivalent dose. The trap kinetics of two high temperature peaks (peaks II and III) from calcitic snail opercula have been investigated resulting in the calculation of lifetimes of 7.4 × 10 7 and 1.4 × 10 11 years for the two peaks respectively. Two measurement sequences, based upon changes in the application and measurement of a test dose, have been applied to peaks II and III, and though both methods were equally successful in dose recovery and production of a dose response curve some differences were observed. Primarily, the use of method 1 lead to dose dependant sensitivity change implying competition effects occurring during irradiation; method 2 did not experience this phenomenon. As a consequence method 2 was chosen as the most appropriate protocol for single-aliquot dating of this material. When assessing the TL behaviour of the two peaks, peak II performed poorly in dose recovery experiments recovering a dose 60-100% larger than that applied. Disproportionate growth of peak II in response to a beta dose applied prior to measurement, compared to growth following regeneration doses indicated that peak II was not suitable for use in single-aliquot protocols. However, dose recovery results for peak III were all within errors of unity of the given dose, and peak III was therefore chosen as the most appropriate peak for TL dosimetry in these single-aliquot procedures. The lifetime of charge in peak III is sufficient to date over many millions of years, and furthermore using the chosen method 2 the dose response curve has a D 0 of 3,250 ± 163 Gy allowing dating to over 3 million years.

Iaith wreiddiolSaesneg
Tudalennau (o-i)725-731
Nifer y tudalennau7
CyfnodolynRadiation Measurements
Cyfrol47
Rhif cyhoeddi9
Dyddiad ar-lein cynnar31 Ion 2012
Dynodwyr Gwrthrych Digidol (DOIs)
StatwsCyhoeddwyd - Medi 2012
DigwyddiadProceedings of the 13th International Conference on Luminescence and Electron Spin - Toruń, Gwlad Pŵyl
Hyd: 10 Gorff 201114 Gorff 2011

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