Status report of JAEA-AMS-TONO: research and technical development in the last four years
Dr Yoko Saito-Kokubu1, Dr Natsuko Fujita1, Dr Takahiro Watanabe1, Dr Akihiro Matsubara1, Ms Chika Ishizaka1, Mr Masayasu Miyake2, Mr Tomohiro Nishio2, Mr Motohisa Kato2, Ms Yumi Ogawa2, Mr Masahiro Ishii3, Dr Kenji Kimura1, Mr Akiomi Shimada1, Mr Nobuhisa Ogata1
1Japan Atomic Energy Agency, Toki, Gifu, Japan, 2PESCO Co., Ltd., Toki, Gifu, Japan, 3Beam Operation Co., Ltd., Takasaki, Gunma, Japan
The JAEA-AMS-TONO facility at the Tono Geoscience Center, Japan Atomic Energy Agency has an accelerator mass spectrometer (JAEA-AMS-TONO-5MV) with a 5 MV Pelletron™ accelerator (15SDH-2, National Electrostatics Corp., US). The JAEA-AMS-TONO-5MV has been used to measure radiocarbon (¹⁴C) in geological samples since the installation at 1997 . In this past decade, the spectrometer enabled us to use a multi-nuclide AMS of ¹⁴C, beryllium-10, aluminium-26 and iodine-129, and we have recently been proceeding test measurement of chlorine-36. In-house projects mainly utilize the spectrometer to determine the age of geological samples in studies into long-term geological stability as a basic research and development related to the geological disposal of high-level radioactive waste. In addition, the spectrometer is also available to the JAEA’s common-use facility program, which is shared use of the AMS for researchers belonging to other research organizations. In response to an increase of samples, we installed a state-of-the-art multi-nuclide AMS with a 300 kV Tandetron™ accelerator (4103Bo-AMS, High Voltage Engineering, Europa B.V., Netherlands) in 2020. Recently, we are driving the development of techniques of isobar separation in AMS and of sample preparation. Ion channeling is applied to remove isobaric interference and we are building a prototype AMS based on this technique for downsizing of AMS. The small sample graphitization for ¹⁴C has been attempted using an automated graphitization equipment (AGE3, Ionplus, Switzerland) equipped with an elemental analyzer (Vario Micro cube, Elementar Analysensysteme GmbH, Germany) .
“Yoko Kokubu is a principal scientist at Japan Atomic Energy Agency.
I develop analytical techniques using AMS and manage the JAEA-AMS-TONO facility.
Our facility with 2 AMSs is used for measurement of C-14, Be-10, Al-26 and I-129 in geological samples etc.
I will report the status of our facility.