Imperial College London
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DrDylanRood

Faculty of Engineering, Department of Earth Science & Engineering

Senior Lecturer
 
 
 
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Contact

 

+44 (0)20 7594 7461d.rood

 
 
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Location

 

4.43Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Wilcken:2022:10.5194/gchron-4-339-2022,
author = {Wilcken, KM and Codilean, AT and Fülöp, R-H and Kotevski, S and Rood, AH and Rood, DH and Seal, AJ and Simon, K},
doi = {10.5194/gchron-4-339-2022},
journal = {Geochronology},
pages = {339--352},
title = {Technical note: Accelerator mass spectrometry of 10Be and 26Al at low nuclide concentrations},
url = {http://dx.doi.org/10.5194/gchron-4-339-2022},
volume = {4},
year = {2022}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Accelerator mass spectrometry (AMS) is currently the standard technique to measure cosmogenic 10Be and 26Al concentrations, but the challenge with measuring low nuclide concentrations is to combine high AMS measurement efficiency with low backgrounds. The current standard measurement setup at ANSTO uses the 3+ charge state with Ar stripper gas at 6 MV for Be and 4 MV for Al, achieving ion transmission through the accelerator for 10Be3+ and 26Al3+ of around 35 % and 40 %, respectively. Traditionally, 26Al measurement uncertainties are larger than those for 10Be. Here, however, we show that 26Al can be measured to similar precision as 10Be even for samples with 26Al  27Al ratios in the range of 10−15, provided that measurement times are sufficiently long. For example, we can achieve uncertainties of 5 % for 26Al  27Al ratios around , typical for samples of late Holocene age or samples with long burial histories. We also provide empirical functions between the isotope ratio and achievable measurement precision, which allow predictive capabilities for future projects and serve as a benchmark for inter-laboratory comparisons. For the smallest signals, not only is understanding the source of 10Be or 26Al background events required to select the most appropriate blank correction method but also the impact of the data reduction algorithms on the obtained nuclide concentration becomes pronounced. Here we discuss approaches to background correction and recommend quality assurance practices that guide the most appropriate background correction method. Our sensitivity analysis demonstrates a 30 % difference between different background correction methods for samples with 26Al  27Al ratios below 10−14. Finally, we show that when the measured signal is small and the number of rare isotope counts is also low, differing 26Al or 10Be concentrations may be obtained from the same data if al
AU  - Wilcken,KM
AU  - Codilean,AT
AU  - Fülöp,R-H
AU  - Kotevski,S
AU  - Rood,AH
AU  - Rood,DH
AU  - Seal,AJ
AU  - Simon,K
DO  - 10.5194/gchron-4-339-2022
EP  - 352
PY  - 2022///
SN  - 2628-3719
SP  - 339
TI  - Technical note: Accelerator mass spectrometry of 10Be and 26Al at low nuclide concentrations
T2  - Geochronology
UR  - http://dx.doi.org/10.5194/gchron-4-339-2022
UR  - https://gchron.copernicus.org/articles/4/339/2022/
UR  - http://hdl.handle.net/10044/1/101624
VL  - 4
ER  -
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