Performance Evaluation of the New AMS System at Accium BioSciences

Abstract

ABSTRACT.A new compact accelerator mass spectrometry (AMS) system dedicated to the measurement of radiocarbon has been commissioned at the Accium BioSciences headquarters in Seattle. The entire facility (including ancillary laboratories for the preparation of graphite targets) has been designed to handle samples with a wide range of 14 C concentrations. In this paper, we discuss the technical details of the new facility and present performance test results demonstrating state-of-theart capabilities. In particular, modern samples can be readily measured with 0.3% precision and accuracy, machine background levels are consistently in the low 10 -16 ( 14 C/ 12 C), and chemical background is approximately equivalent to a fraction of modern of 0.004. In addition, when 100-times-modern samples were processed, no increase in background was observed, either during sample processing or during AMS measurement. This corresponds to a dynamic range for 14 C analysis of 6 orders of magnitude.

Radiocarbon AMS Data Analysis: From Measured Isotopic Ratios to 14C Concentrations

“…Increasing the number of dimensions would require a corresponding increase in measurement points through which to fit the efficiency function. The experience collected at Accium BioSciences with the NEC 1.5SDH-1 Pelletron AMS system (Zoppi et al 2007) suggests that, if the reproducibility of the Accium AMS system can be increased, it can be done using a " 13 C current-measurement time" correction. Such an approach becomes essential when 13 C-enriched carbon carrier is added to biological samples to simultaneously determine total carbon masses and 14 C concentrations (Zoppi and Arjomand 2009).…”

XCAMS: The compact 14C accelerator mass spectrometer extended for 10Be and 26Al at GNS Science, New Zealand

“…Fourteen of these systems were built by National Electrostatic Corporation (NEC). Several of these systems have been described, including customizations and performance details [4][5][6][7][8][9]. The experience with and further development of these systems have contributed significantly to enhanced performance in later models.…”

Archaeological Data Recovery at Fish Creek Slough Site (41DL436)

“…Radiocarbon samples were analyzed by DirectAMS/Accium Biosciences in Seattle (Zoppi et al 2007). The collagen samples were combusted and reduced to graphite in sealed vials and measured using a National Electrostatics Corporation Model 1.5SDH-1 Pelletron Accelerator.…”

“…The collagen samples were combusted and reduced to graphite in sealed vials and measured using a National Electrostatics Corporation Model 1.5SDH-1 Pelletron Accelerator. The Direct/AMS laboratory has an overall precision and accuracy of 0.3 to 0.5 percent for modern samples (Zoppi et al 2007). Table 2 presents the results of the analysis.…”