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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
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.
Watanabe, Takahiro; Fujita, Natsuko; Matsubara, Akihiro; Miyake, Masayasu*; Nishio, Tomohiro*; Ishizaka, Chika; Kokubu, Yoko
Geochemical Journal, 55(4), p.277 - 281, 2021/00
Times Cited Count：1 Percentile：18.67(Geochemistry & Geophysics)Small-mass radiocarbon dating less than 0.1 mg carbon has been developed by Accelerator mass spectrometry (AMS) and manual preparation techniques using the vacuum glass lines. Because geological samples are limited for the dating in many cases, preparation techniques should be improved for small samples and high efficiency analysis. For radiocarbon dating of geological and other organic samples, small-mass graphitization of international standard reference materials (ca. 0.1 and 0.05 mg carbon) was evaluated using the elemental analyzer and automated graphitization equipment 3 (EA-AGE3; IonPlus AG) in our study. Additionally, this paper presents the first data for the small samples by the EA-AGE3. The average radiocarbon concentration of the small-mass international standards (NIST-SRM4990C, IAEA-C5, and C7) prepared by the EA-AGE3 were agreement with the consensus values within 
2
. Therefore, small-mass graphitization using the EA-AGE3 can be adapted for AMS radiocarbon measurements in our case (down to ca. 0.05 mg carbon).
Watanabe, Takahiro; Ishii, Chikako; Ishizaka, Chika; Niwa, Masakazu; Shimada, Koji; Sawai, Yuki*; Tsuchiya, Noriyoshi*; Matsunaka, Tetsuya*; Ochiai, Shinya*; Nara, Fumiko*
Journal of Mineralogical and Petrological Sciences, 116(3), p.140 - 158, 2021/00
Times Cited Count：3 Percentile：49.56(Mineralogy)A portable energy dispersive X-ray fluorescence spectrometer (potable XRF) can be an effective tool for detecting chemical elements in various materials, such as geological, and environmental samples. In this study, working curves were confirmed using reference materials, such as igneous rocks and other geochemical standards, distributed by national and international organizations. Subsequently, quantification and semi-quantification analyses were performed by the portable XRF for inorganic elements in (A) fault rocks, (B) lake sediments from the middle Japan, and (C) soils with paleotsunami deposits from the Pacific coast of northeast Japan. Twenty-four elements (Mg-U) in these geological samples were measured by potable XRF using our working curves. Measured values by the portable XRF of the samples were good agreement with the reported values in almost cases.
Fujita, Natsuko; Matsubara, Akihiro; Miyake, Masayasu*; Watanabe, Takahiro; Kokubu, Yoko; Kato, Motohisa*; Okabe, Nobuaki*; Isozaki, Nobuhiro*; Ishizaka, Chika*; Nishio, Tomohiro; et al.
Proceedings of the 8th East Asia Accelerator Mass Spectrometry Symposium and the 22nd Japan Accelerator Mass Spectrometry symposium (EA-AMS 8 & JAMS-22), p.34 - 36, 2020/00
no abstracts in English
Kokubu, Yoko; Matsushi, Yuki*; Ishizaka, Chika*; Hirao, Noriaki*; Yonaga, Yusuke; Yoshikawa, Kiyotaka*
JAEA-Testing 2019-002, 101 Pages, 2019/11
JAEA-Testing-2019-002.pdf:4.69MB
This report provides a description of sample preparation method for measurement of in-situ belliyum-10 (
Be) and allumium-26 (
Al) in terrestrial quartz using accelerator mass spectrometry at Tono Geoscience Center, Japan Atomic Energy Agency. The report is based on the laboratory manual "Chemistry for in-situ Be and Al measurement for terrestrial quartz by AMS at MALT ver.1.3 and ver.2.2" prepared by ph.D Matsushi at Kyoto University.
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：2 Percentile：26.4(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.
Watanabe, Takahiro; Kokubu, Yoko; Fujita, Natsuko; Ishizaka, Chika*; Nishio, Tomohiro; Matsubara, Akihiro*; Miyake, Masayasu; Kato, Motohisa*; Isozaki, Nobuhiro*; Torazawa, Hitoshi*; et al.
JAEA-Conf 2018-002, p.116 - 119, 2019/02
AMS is widely used for radiocarbon dating of geological samples. However, improvement in efficiency of sample preparation techniques are needed for high-time resolution dataset. In 2016, automated graphitization equipment (AGE3, IonPlus AG) has been installed in Toki Research Institute of Isotope Geology and Geochronology, Tono Geoscience Center, JAEA. Background values and carbon recovery rates during preparation process of AGE3 should be estimated before application in radiocarbon dating. In this study, the AGE3 system was evaluated using the international standard materials (IAEA-C1, C4, C5, C6, C7, C9 and NIST-SRM4990C) at JAEA-AMS-TONO. Graphite samples was prepared by the AGE3 system and radiocarbon concentration of these standards was measured by AMS. The results were agreement with the consensus values. Background values were 0.150.01 pMC (IAEA-C1) using the AGE3 system. Therefore, we concluded that the system can be adapted for radiocarbon dating of geological samples.
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
Fujita, Natsuko; Miyake, Masayasu; Watanabe, Takahiro; Kokubu, Yoko; Matsubara, Akihiro*; Kato, Motohisa*; Okabe, Nobuaki; Isozaki, Nobuhiro*; Ishizaka, Chika*; Torazawa, Hitoshi*; et al.
Dai-31-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.92 - 95, 2018/12
no abstracts in English
Miyawaki, Nobumasa; Okumura, Susumu; Kurashima, Satoshi; Kashiwagi, Hirotsugu; Yoshida, Kenichi; Yuri, Yosuke; Yuyama, Takahiro; Ishibori, Ikuo; Agematsu, Takashi; Ishizaka, Tomohisa; et al.
Proceedings of 4th Annual Meeting of Particle Accelerator Society of Japan and 32nd Linear Accelerator Meeting in Japan (CD-ROM), p.604 - 606, 2007/00
The main probe of the JAEA AVF cyclotron has been modified to measure a beam phase width in the accelerating region without extracting the beam from the cyclotron, which could cause the beam loss at the extraction device. The main probe consists of a carbon block for a beam current measurement and a plastic scintillator for a beam phase measurement. A correlation between the beam phase width and the position of phase slits was confirmed.
Fujita, Natsuko; Matsubara, Akihiro; Miyake, Masayasu*; Watanabe, Takahiro; Kokubu, Yoko; Kato, Motohisa*; Okabe, Nobuaki*; Isozaki, Nobuhiro*; Ishizaka, Chika*; Nishio, Tomohiro; et al.
no journal, ,
no abstracts in English
C dating using EA-AGE3 at JAEA-AMS-TONOWatanabe, Takahiro; Kokubu, Yoko; Fujita, Natsuko; Ishizaka, Chika*; Nishio, Tomohiro; Matsubara, Akihiro; Miyake, Masayasu*; Isozaki, Nobuhiro*; Nishizawa, Akimitsu*
no journal, ,
Accelerator Mass Spectrometry is widely used for radiometric dating of geological samples. However, improvement in efficiency of sample preparation techniques and trace analysis are needed for high-time resolution dataset. To improve in efficiency of sample preparation techniques and trace analysis, the elemental analyzer and automated graphitization equipment 3 (EA-AGE3) were installed at the Tono Geoscience Center, JAEA. In this study, small amount graphitization of international standard reference materials for radiocarbon dating was tested by the EA-AGE3. For the trace analysis, radiocarbon measurements were performed by the AMS system. The radiocarbon concentrations of the standard materials were good agreement with the consensus values by the international radiocarbon conference within 2.
