Hostname: page-component-77c89778f8-cnmwb Total loading time: 0 Render date: 2024-07-17T09:47:32.990Z Has data issue: false hasContentIssue false

Effect of Beam Transmission of Stable Isotopes on Online δ13C for SSAMS

Published online by Cambridge University Press:  23 July 2019

G V Ravi Prasad*
Affiliation:
Center for Applied Isotope Studies, University of Georgia, 120 Riverbend Rd., Athens, GA 30602, USA
Alexander Cherkinsky
Affiliation:
Center for Applied Isotope Studies, University of Georgia, 120 Riverbend Rd., Athens, GA 30602, USA
Randy Culp
Affiliation:
Center for Applied Isotope Studies, University of Georgia, 120 Riverbend Rd., Athens, GA 30602, USA
*
*Corresponding author. Email: gvrp@uga.edu.

Abstract

It is known that 12C beam transmission through the accelerator decreases at high beam currents. This effect depends on machine design and varies across different types of AMS instruments. For beam currents of about 100 μA, the effect is small on the 500 kV tandem CAMS unit, whereas beam saturation is observed for similar high beam currents on the 250 kV SSAMS unit. While this effect is very evident for high 12C beam currents, we have also observed that even the 13C beam is found to suffer modest transmission loss with beam current. As a result, the 13C/12C ratio does not remain constant with beam current. By correcting for the effects of 12C beam saturation and decreased 13C transmission, we have obtained online δ13C values that are more accurate and precise at moderately high beam currents for SSAMS.

Type
Conference Paper
Copyright
© 2019 by the Arizona Board of Regents on behalf of the University of Arizona 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

Selected Papers from the 23rd International Radiocarbon Conference, Trondheim, Norway, 17–22 June, 2018

References

REFERENCES

Bard, E, Tuna, T, Fagault, Y, Bonvalot, L, Wacker, L, Fahrni, S, Synal, HA. 2015. AixMICADAS, the accelerator mass spectrometer dedicated to 14C recently installed in Aix-en-Provence, France. Nuclear Instruments and Methods in Physics Research B 361:8086.CrossRefGoogle Scholar
Calvo, EC, Santos, FJ, Lopez-Gutierrez, JM, Padilla, S, Garcia-Leon, M, Heinemeier, J, Schnabel, C, Scognamiglio, G. 2015. Status report of the 1 MV AMS facility at the Centro Nacional de Aceleradores. Nuclear Instruments and Methods in Physics Research B 361:1319.CrossRefGoogle Scholar
Freeman, SPHT, Dougans, A, McHargue, L, Wilcken, KM, Xu, S. 2008. Performance of the new single stage accelerator mass spectrometer at the SUERC. Nuclear Instruments and Methods in Physics Research B 266:22252228.CrossRefGoogle Scholar
Freeman, SPHT, Cook, GT, Dougans, A, Naysmith, P, Wilcken, KM, Xu, S. 2010. Improved SSAMS performance. Nuclear Instruments and Methods in Physics Research B 268:715717.10.1016/j.nimb.2009.10.012CrossRefGoogle Scholar
Linares, R, Macario, KD, Santos, GM, Carvalho, C, dos Santos, HC, Gomes, PRS, Castro, MD, Oliveira, FM, Alves, EQ. 2015. Radiocarbon measurements at LAC-UFF: recent performance. Nuclear Instruments and Methods in Physics Research B 361:341345.10.1016/j.nimb.2015.05.025CrossRefGoogle Scholar
Prasad, GVR, Noakes, JE, Cherkinsky, A, Culp, R, Dvoracek, D. 2013. The new 250kV single stage AMS system at CAIS, university of Georgia: performance comparison with a 500kV compact tandem machine. Radiocarbon 55:319324.CrossRefGoogle Scholar
Prasad, GVR, Cherkinsky, A, Culp, R, Dvoracek, D. 2015. Two years since SSAMS: Status of 14C AMS at CAIS. Nuclear Instruments and Methods in Physics Research B 361:697110.1016/j.nimb.2015.06.033CrossRefGoogle Scholar
Prasad, GVR, Culp, R, Cherkinsky, A. 2019. δ13C correction to AMS data: values derived from AMS vs IRMS values. Nuclear Instruments and Methods in Physics Research B 455:244249CrossRefGoogle Scholar
Skog, G. 2007. The single stage AMS machine at Lund University: status report. Nuclear Instruments and methods in Physics Research B 259:16.10.1016/j.nimb.2007.01.190CrossRefGoogle Scholar
Skog, G, Rundgren, M, Skold, P. 2010. Status of the Single Stage AMS machine at Lund University after 4 years of operation. Nuclear Instruments and Methods in Physics Research B 268:895897.CrossRefGoogle Scholar
Synal, HA, Stocker, M, Suter, M. 2007. MICADAS: a new compact radiocarbon AMS system. Nuclear Instruments and Methods in Physics Research B 259:713.CrossRefGoogle Scholar