Comparison of ⁴¹Ca analysis on 0.5 MV and 5 MV-AMS systems

Schulze-Konig, T., Maden, C., Denk, E., Freeman, S. , Stocker, M., Suter, M., Synal, H.A. and Walczyk, T. (2010) Comparison of ⁴¹Ca analysis on 0.5 MV and 5 MV-AMS systems. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 268, pp. 752-755. (doi: 10.1016/j.nimb.2009.10.022)

Abstract

A comparative study was made between the compact AMS system at the PSI/ETH Laboratory of Ion Beam Physics in Zurich with 0.5 MV terminal voltage and the 5 MV-AMS system at the Scottish Universities Environmental Research Centre (SUERC), Glasgow. Overall 34 urinary samples with ⁴¹Ca/⁴⁰Ca ratios in the range from 4x10^-11 to 3x10^-10 were processed to CaF2 and aliquots of the same material were measured on both instruments. Measurements on the compact AMS system were performed in charge state 3+ achieving a transmission of 4% at 1.7 MeV beam energy. Under these conditions a suppression of the interference ⁴¹K is virtually impossible. However, samples with an excess of potassium can be identified by a shift of the ⁴¹Ca/⁴¹K peak in the DE E histogram of the gas ionization detector employed and a criterion for data rejection can be defined. An overall precision of 4% and a ⁴¹Ca/⁴⁰Ca background level of 5 1012 have been reached. For studies with higher demands on the detection limit AMS systems like the one at SUERC are attractive: in charge state 5+ and using a gas stripper beam energy of 27 MeV, a transmission of 5%, a ⁴¹K suppression factor of 500 and a ⁴¹Ca/⁴⁰Ca background level of 3x10^-14 are achieved. We demonstrate that both systems are well suited for large-scale ⁴¹Ca biomedical applications.

• Item Type: Articles
• Keywords: compact AMS; biomedical AMS; 41Ca; Ca41; Accelerator Mass Spectrometry
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Freeman, Professor Stewart
• Authors: Schulze-Konig, T., Maden, C., Denk, E., Freeman, S., Stocker, M., Suter, M., Synal, H.A., and Walczyk, T.
• Subjects: G Geography. Anthropology. Recreation > GE Environmental Sciences
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
• Publisher: Elsevier
• ISSN: 0168-583X
• Published Online: 08 October 2010