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Fujita, Natsuko; Miyake, Masayasu*; Matsubara, Akihiro; Kokubu, Yoko; Klein, M.*; Scognamiglio, G.*; Mous, D. J. W.*; Columna, E. L.*; Shimada, Akiomi; Ishimaru, Tsuneari
Nuclear Instruments and Methods in Physics Research B, 533, p.91 - 95, 2022/12
Times Cited Count：0 Percentile：0.02(Instruments & Instrumentation)In the Tono Geoscience Center, Japan Atomic Energy Agency, investigation of deep underground environments for R&D program related to the geological disposal of High-Level Radioactive Waste has been performed by using various dating systems including an AMS system. In response to the increasing demand for our AMS measurements especially from a newly established R&D program supporting development of technology for geological disposal of HLW, a state-of-the-art multi-nuclide AMS system was installed. This system is equipped with a 300 kV AMS. The system has capability to measure four nuclides: carbon-14, beryllium-10, aluminium-26 and iodine-129. The system structure and features, as well as the results of performance test will be presented.
Fujita, Natsuko; Matsubara, Akihiro; Kimura, Kenji; Jinno, Satoshi; Kokubu, Yoko
Nuclear Instruments and Methods in Physics Research B, 532, p.13 - 18, 2022/12
Times Cited Count：0 Percentile：0.02(Instruments & Instrumentation)Over the last decade, significant technological advances were made to downsize the AMS systems. Japan Atomic Energy Agency has started a project for developing a prototype downsized AMS system (with the footprint of the system is 1.9 m 
1.9 m) based on the surface stripper technique. Although the system configuration using an ion source, magnets, and detectors is similar to that in conventional systems, there is no tandem accelerator as well as a gas stripper. The ion acceleration is provided in the ion source (maximum ion energy 40 keV). For proof-of-principle experiments, we have planned two steps: (1) Observation of the specular reflection and the dissociation by using a compact electrostatic analyzer located just behind the stripper, and (2) Demonstration of 
C measurement, along with the experimental confirmation of the isobar suppression capability of the surface stripper.
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.
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：21.63(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).
Matsubara, Akihiro*; Fujita, Natsuko; Ishii, Kunikazu*; Kimura, Kenji*
Hoshasen (Internet), 45(3), p.134 - 138, 2020/04
no abstracts in English
Kokubu, Yoko; Nishio, Tomohiro; Fujita, Natsuko; Matsubara, Akihiro
Proceedings of the 8th East Asia Accelerator Mass Spectrometry Symposium and the 22nd Japan Accelerator Mass Spectrometry symposium (EA-AMS 8 & JAMS-22), p.91 - 93, 2020/00
no abstracts in English
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
2 mMatsubara, Akihiro; Fujita, Natsuko; Kimura, Kenji
Proceedings of the 8th East Asia Accelerator Mass Spectrometry Symposium and the 22nd Japan Accelerator Mass Spectrometry symposium (EA-AMS 8 & JAMS-22), p.57 - 59, 2020/00
no abstracts in English
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：27.27(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.
C ages and calendar years of Japanese nails measured with accelerator mass spectrometryNagata, Kazahiro*; Furunushi, Yasuko*; Matsubara, Akihiro*; Kokubu, Yoko; Nakamura, Toshio*
Tetsu To Hagane, 105(4), p.488 - 491, 2019/04
Times Cited Count：1 Percentile：7.95(Metallurgy & Metallurgical Engineering)The Japanese nails had been produced by the traditional ironmaking way of Tatara until the Edo period since the late of 6 Century. The quality of the Japanese nails is affected from steel produced by Tatara in each age. The C ages of 3 Japanese nails collected at shrines and temples at their repair were measured with accelerator mass spectrometry and calibrated to calendar years. Each C age provided plural calendar year periods with definite probabilities, and one of the periods determined in comparison with the history of temples and their repair records. The production ages of nails used in the Daibutuden of the Todaiji temple, the living quarters of the Manjuin temple and the Zaoudo of the Yoshino-Kongoji temple are before 1692, the 12 Century and before 1592, respectively, when they were repaired or reconstructed.
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.
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
Matsubara, Akihiro*; Fujita, Natsuko; Miyake, Masayasu; Isozaki, Nobuhiro*
JAEA-Conf 2018-002, p.68 - 71, 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
Fujita, Natsuko; Miyake, Masayasu; Watanabe, Takahiro; Kokubu, Yoko; Ishimaru, Tsuneari; Matsubara, Akihiro*; Nishio, Tomohiro*; Kato, Motohisa*; Isozaki, Nobuhiro*; Torazawa, Hitoshi*; et al.
JAEA-Conf 2018-013, p.96 - 99, 2019/02
no abstracts in English
Matsubara, Akihiro*; Fujita, Natsuko; Miyake, Masayasu; Isozaki, Nobuhiro*; Nishizawa, Akimitsu*
JAEA-Conf 2018-013, p.135 - 139, 2019/02
no abstracts in English
Matsubara, Akihiro*; Fujita, Natsuko; Miyake, Masayasu; Isozaki, Nobuhiro*
Dai-31-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.108 - 111, 2018/12
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
Matsubara, Akihiro*; Fujita, Natsuko; Ishii, Kunikazu*
Nuclear Instruments and Methods in Physics Research B, 437, p.81 - 86, 2018/12
Times Cited Count：1 Percentile：13.39(Instruments & Instrumentation)no abstracts in English
Saito, Hiroshi; Nozawa, Takashi; Takemiya, Hiroshi; Seki, Akiyuki; Matsubara, Takeshi; Saito, Kimiaki; Kitamura, Akihiro
JAEA-Review 2017-040, 34 Pages, 2018/03
JAEA-Review-2017-040.pdf:9.52MB
The accidents at Fukushima Daiichi Nuclear Power Station on March 11th 2011, released significant amount of radionuclide to the environment. It has migrated to the human habitation and raised concerns of possible effect on human health, and for that a lot of researches have been performed. JAEA created and opened "Database for Radioactive Substance Monitoring Data" for usage of obtained data. For accurate modelling and future forecast using numerical code and the data, "Supporting Environment for Processing Simulation Codes" has been operated. In addition, research results have been opened as Q&A style "Knowledge Base for Environmental Remediation" in JAEA's website. The "Comprehensive Evaluation System" composed of these components, should act more interrelated and integrated as one system. Besides, information dissemination is not enough to the outside. The report summarizes the current status, remaining issues and expected improvement of each component and the system.
