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Kokubu, Yoko; Fujita, Natsuko; Watanabe, Takahiro; Matsubara, Akihiro; Ishizaka, Chika; Miyake, Masayasu*; Nishio, Tomohiro*; Kato, Motohisa*; Ogawa, Yumi*; Ishii, Masahiro*; et al.
Nuclear Instruments and Methods in Physics Research B, 539, p.68 - 72, 2023/06
Times Cited Count：2 Percentile：28.72(Instruments & Instrumentation)The JAEA-AMS-TONO facility at the Tono Geoscience Center, JAEA has an accelerator mass spectrometer (JAEA-AMS-TONO-5MV). The spectrometer enabled us to use a multi-nuclide AMS of carbon-14 (
C), beryllium-10, aluminium-26 and iodine-129, and we have recently been proceeding test measurement of chlorine-36. In response to an increase of samples, we installed a state-of-the-art multi-nuclide AMS with a 300 kV Tandetron accelerator 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 C has been attempted using an automated graphitization equipment equipped with an elemental analyzer.
Kokubu, Yoko; Matsubara, Akihiro; Fujita, Natsuko; Kuwabara, Jun; Kinoshita, Naoki
JAEA-Technology 2021-028, 33 Pages, 2022/02
JAEA-Technology-2021-028.pdf:2.18MB
Japan Atomic Energy Agency (JAEA) has two facilities of accelerator mass spectrometry, JAEA-AMS-TONO and JAEA-AMS-MUTSU at Tono Geoscience Center and Aomori Research and Development Center, respectively. In this report, characteristics of each facility and results of standard samples in the inner-comparison test of carbon isotope measurement will be described. Both facilities have been used for research by not only JAEA's staff but also researchers who belong to universities and other institutes on the shared use program of JAEA facilities. Recently, researchers trend to use both facilities with the expansion of demand for the carbon isotope measurement by using the accelerator mass spectrometer (AMS). However, each facility has a spectrometer made by a different manufacturer and equipped with different mechanical components. There is a difference in each ability to the carbon isotope measurement such as background level. This is, for example, due to different ion injection system adapted at each spectrometer. Further, each facility uses a different analytical method adjusted to each main research field. When a researcher uses both facilities, the researcher understands more about the characteristics and need to make a suitable choice of a facility for samples and the analytical method. The report presents a detailed information of characteristics of the spectrometer, sample preparation method and analytical method, and of ability of the measurement based on the inner-comparison test.
Kokubu, Yoko; Fujita, Natsuko; Miyake, Masayasu; Watanabe, Takahiro; Ishizaka, Chika; Okabe, Nobuaki; Ishimaru, Tsuneari; Matsubara, Akihiro*; Nishizawa, Akimitsu*; Nishio, Tomohiro*; et al.
Nuclear Instruments and Methods in Physics Research B, 456, p.271 - 275, 2019/10
Times Cited Count：6 Percentile：48.20(Instruments & Instrumentation)JAEA-AMS-TONO has been in operation at the Tono Geoscience Center, Japan Atomic Energy Agency since 1998 and 20 years have passed from the beginning of its utilization. The AMS system is a versatile system based on a 5 MV tandem Pelletron type accelerator. The system has been used to measure carbon-14 (C), beryllium-10 (
Be) and aluminium-26 (
Al). In addition, the development of measurement of iodine-129 (
I) has been started. The main use is measurement of C in geological samples for dating studies in neotectonics and hydrogeology. In order to increase the speed of sample preparation, we introduced the automated graphitization equipment and made a gas-strip line to collect dissolved inorganic carbon in groundwater samples. Measurement of Be and Al has been used for geoscience studies and the detection limit in the measurement of Be was improved by 
Be-counting suppression. Recently tuning of measurement condition of I has been progressed.
I/
I ratio at JAEA-AMS-TONOOkabe, Nobuaki; Fujita, Natsuko; Matsubara, Akihiro*; Miyake, Masayasu; Nishio, Tomohiro*; Nishizawa, Akimitsu*; Isozaki, Nobuhiro*; Watanabe, Takahiro; Kokubu, Yoko
JAEA-Conf 2018-002, p.51 - 54, 2019/02
no abstracts in English
Kokubu, Yoko; Fujita, Natsuko; Matsubara, Akihiro*; Nishizawa, Akimitsu*; Nishio, Tomohiro; Miyake, Masayasu; Ishimaru, Tsuneari; Watanabe, Takahiro; Ogata, Nobuhisa; Shimada, Akiomi; et al.
JAEA-Conf 2018-002, p.5 - 8, 2019/02
no abstracts in English
Ishimaru, Tsuneari
JAEA-Conf 2018-013, p.13 - 16, 2019/02
In the Tono Geoscience Center, JAEA-AMS-TONO was introduced in March 1997 and it will be the 20th year in this year. After introduction, we maintained the carbon-14 measurement first and we were able to steadily accumulate results.
Matsubara, Akihiro; Fujita, Natsuko; Miyake, Masayasu*; Nishizawa, Akimitsu*; Kokubu, Yoko
Dai-17-Kai AMS Shimpojiumu Hokokushu, p.40 - 45, 2015/12
no abstracts in English
Be analysis and morphometric aspect in Sangun catchment Area, Fukuoka Prefecture, JapanPachri, H.*; Mitani, Yasuhiro*; Ikemi, Hiroaki*; Nakanishi, Ryunosuke*; Kokubu, Yoko
Journal of Geological Resource and Engineering, 3(4), p.163 - 172, 2015/09
Recently, the contributions of slope failures have been difficult to quantify over the time scales of the sediment concentrations in Sangun catchment area, Fukuoka Prefecture. This paper describes how cosmogenic nuclide methods have provided information about the geomorphic process by utilizing Be. The Be/
Be ratios were measured by AMS. We assume that the cosmogenic nuclide concentrations stored in the sediment of a river can increase or decrease, depending on the amount of mixing of sediments during transport through the fluvial system. As results, the Be concentrations have been calculated to determine the short term sediment mixing rate in the catchment area. Therefore, the relationship between the morphometrics of the drainage basin, the sediment concentration by Be analysis and the contribution of landslides to landscape changes over timescales of several years have been investigated in Sangun catchment area.
Matsubara, Akihiro; Fujita, Natsuko; Nishizawa, Akimitsu*; Miyake, Masayasu*; Nishio, Tomohiro*; Owaki, Yoshio*; Sanada, Katsuki*; Kokubu, Yoko; Ishimaru, Tsuneari
Dai-27-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.47 - 51, 2015/03
Steady progress has been made in the development of a multi-nuclide AMS system for measurement of rare radionuclides (Be, C, and Al) to apply geochronological dating methods. In this article we will report the current status of the JAEA-AMS-TONO.
Yasue, Kenichi; Hirouchi, Daisuke*; Matsubara, Akihiro; Kokubu, Yoko
no journal, ,
no abstracts in English
Be and Al by AMSKokubu, Yoko; Matsubara, Akihiro; Fujita, Natsuko; Nishio, Tomohiro*; Owaki, Yoshio*; Sanada, Katsuki*; Nishizawa, Akimitsu*; Miyake, Masayasu*
no journal, ,
Cosmogenic nuclides of Be and Al are used for studies such as estimation of exposure age and erosion rate of rock. In order to measure traces of Be and Al by accelerator mass spectrometry (AMS) in these studies, reagents with low levels of Be and Al are needed. In this study, ratios of Be/Be or Al/
Al in several reagents were compared. The reagents were oxides for evaluation of blank in measurement and standard solutions for atomic absorption spectrometry (AAS) or inductively coupled plasma optical emission / mass spectrometry (ICP) for carrier and evaluation of process blank. The ratios were measured in JAEA-AMS-TONO. The ratios of Be/Be in the Be oxides and the Be standard solutions were approximately 10
10
levels. The Be Standard solutions for AAS and ICP supplied by Merck had lower ratios of Be/Be than those supplied by Wako and Kanto chemical.
Ikemi, Hiroaki*; Pachri, H.*; Kokubu, Yoko; Mitani, Yasuhiro*; Kuroki, Takahito*
no journal, ,
One of issues in the comprehensive river-sediment management is to develop how to estimate a sediment production from a mountainous stream. In this study, beryllium isotopes of quartz extracted from sediment samples have been analyzed by JAEA-AMS-TONO to clarify a sediment dynamics in mountain streams. The sediment samples have been collected at four riverbeds and one hillslope in two different sub-catchments (A and B) of a Mesozoic granitic block located in the Umi-kawa river basin, Fukuoka. The sample of the catchment B shows a little bit higher value in Be-content than those of catchment A. This result indicates that the river sediment in the catchment B includes quartz grains that have been exposed on a ground surface for a long time compared with the catchment A. It is also possible that the river sediment in the catchments A contains more landslide materials because the landslide materials, which have come from a deeper part, might have a lower value in Be-content.
