Present status in the preparation methods for radiocarbon dating at JAEA-AMS-TONO

Watanabe, Takahiro   ; Kokubu, Yoko   ; Fujita, Natsuko   ; Matsubara, Akihiro*; Nishio, Tomohiro*; Miyake, Masayasu; Kato, Motohisa*; Isozaki, Nobuhiro*; Torazawa, Hitoshi*; Nishizawa, Akimitsu*; Ishimaru, Tsuneari 

Radiocarbon dating by Accelerator Mass Spectrometry is widely used for earth and environmental sciences. For high-precision analyses, automatic preparation system and standard methods are needed. The preparation system by elemental analyzer (EA) has been reported. However, we should make clear the changes in background level during the preparation. In this study, we continued radiocarbon dating of international standard materials using the EA at JAEA-AMS-TONO. The radiocarbon concentrations of the standard materials were agreement with the consensus values within 2 sigma.