We present our first 14 C in-situ results for calibration and system blanks from the recently completed Australian Nuclear Science and Technology Organisation (ANSTO) - University of Wollongong (UOW) in-situ 14 C extraction system. System performance parameters and quality is evidenced by low 14 C blanks and good reproducibility for multiple targets from different reference materials. The 14 C extraction scheme exploits the high temperature phase transformation of quartz to cristobalite in order to quantitatively extract the carbon as CO 2 . The in-situ 14 C extraction system comprises three independently operated and modular units that are used for initial in-vacuo removal of meteoric 14 C, followed by offline high-temperature heating of quartz to release trapped cosmogenic in-situ 14 C, and finally CO 2 gas purification and mass measurement. The design allows for rapid sample throughput of about 6 samples per week with samples masses ranging between 0.5 and 4 g of clean quartz. Other features include single-pass catalytic oxidation using mixed copper (I,II) oxide as catalyst, use of UHV-compatible components and of vacuum annealed copper tubing. We present results for sets of purified quartz samples prepared from CRONUS-A, CRONUS-R and CRONUS-N inter-comparison materials, with final averages consistent with published values. Following extraction and cleaning, CO 2 gas aliquots for some of the samples were analysed using the ETH Zürich CO 2 gas ion source at the ETH MICADAS AMS facility in addition to CO 2 being graphitised using the ANSTO laser-heated graphitisation micro-furnace and then analysed on ANSTO's ANTARES AMS facility. System blanks using either CO 2 or graphite ion-sources at both facilities are on the order of ∼1 x 10 4 atoms.
Publication Details Citation
Fulop, R. H., Fink, D., Yang, B., Codilean, A. T., Smith, A. M., Wacker, L., Levchenko, V., & Dunai, T. J. (2018). The ANSTO - University of Wollongong in-situ 14C extraction laboratory. Faculty of Science, Medicine and Health - Papers: Part B. https://doi.org/10.1016/j.nimb.2018.04.018. Retrieved from https://ro.uow.edu.au/smhpapers1/76
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