160 keV 26Al-AMS with a single-stage accelerator mass spectrometer

Richard P Shanks,Stewart P.H.T Freeman

doi:10.1016/j.nimb.2015.07.121

Abstract

Proof-of-principle 26Al-AMS analysis is achieved with a single-stage accelerator mass spectrometer (SSAMS) utilising very low ion energy. The SSAMS operates by discriminating against atomic isobar interference in a negative ion source and suppressing molecules with thick gas stripper. Resulting 1+ ions counting is with a surface barrier detector. The NEC designed SSAMS for 14C analysis is a popular model accelerator mass spectrometer and the developed further capability might be a significant addition to established 26Al-AMS capacity. Measurements at these energies should also be sufficient for alternative 26Al positive-ion mass spectrometry (PIMS).

Highlights

26Al is a cosmogenic and anthropogenic radionuclide with diverse applications in geological, environmental and biological sciences [1,2,3,4,5,6]
The MV tandem accelerator mass spectrometers typically employed in 26Al measurements will be capable of 10Be detection
This measurement of in situ produced terrestrial cosmogenic radionuclides is normally preferred because of the correspondingly larger ions beams that can be made from common sample material

Summary

Introduction

Sensitive accelerator mass spectrometry (AMS) is able to detect 26Al as low as 1 atom in 1016 total sample Al atoms, but the technique sufferers from the low electron affinity of aluminium. The MV tandem accelerator mass spectrometers typically employed in 26Al measurements will be capable of 10Be detection. This measurement of in situ produced terrestrial cosmogenic radionuclides is normally preferred because of the correspondingly larger ions beams that can be made from common sample material. Developing aluminium AMS on small radiocarbon spectrometers could promote Al-AMS and it applications by expanding the installed base of capable instruments, with implications for analysis cost reductions. Interferences to 14C with ion energy of

Experiments

Results

Conclusion

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Discussion