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Minamitani, Fumina; Nishio, Tomohiro; Fujita, Natsuko; Maeta, Yusuke; Miyake, Masayasu*; Matsubara, Akihiro*; Jinno, Satoshi; Ogita, Yasuhiro; Watanabe, Takahiro
Nuclear Instruments and Methods in Physics Research B, 579, p.166245_1 - 166245_7, 2026/10
Times Cited Count：0 Percentile：0.00(Instruments & Instrumentation)The Tono Geoscience Centre has started to build up a small analysis of radiocarbon using cementite. It is characterised by homogeneous target synthesis and stable measurements with high accuracy and low background. In order to establish the optimum cementite preparation method at the centre, the type of iron, conditions of use, reaction yield, reproducibility of measurement and background were investigated. In sample preparation, target production in high yield was successfully achieved by devising the conditions for the use of iron catalysts. Although the measurement conditions are still under investigation, the beam intensity was found to be sufficient for the measurement and the prescisions were relatively high. This presentation will report on the characteristics of small-scale analysis with cementite at this centre.
Minamitani, Fumina; Nishio, Tomohiro; Fujita, Natsuko; Maeta, Yusuke; Miyake, Masayasu*; Matsubara, Akihiro*; Kitano, Toshihiko*; Jinno, Satoshi; Watanabe, Takahiro
Dai-26-Kai AMS Shimpojiumu Hokokushu (Internet), p.11 - 16, 2026/06
no abstracts in English
Fujita, Natsuko; Maeta, Yusuke; Miyake, Masayasu*; Matsubara, Akihiro*; Uno, Sadanori*; Omae, Akiomi*; Jinno, Satoshi; Minamitani, Fumina; Watanabe, Takahiro; Nishio, Tomohiro; et al.
Dai-37-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.22 - 25, 2026/03
no abstracts in English
Jinno, Satoshi; Matsubara, Akihiro*; Fujita, Natsuko; Kimura, Kenji
Isotope News, (801), p.2 - 5, 2025/10
Accelerator Mass Spectrometry (AMS) is widely used in archaeology and geosciences, and since the 2000s, downsized AMS with an acceleration voltage of 200
500 kV has been put to practical use mainly for 
C dating. However, the beam divergence due to collisions with gases increases at accelerating energies below 100 keV, resulting in a decrease in transmittance. Therefore, we are investigating charge conversion and dissociation of interfering molecules on KCl, SnTe, and Au crystal surfaces using the crystal surface stripper method we have developed. In this article, we report on the position of our research and the current progress.
Fujita, Natsuko; Miyake, Masayasu; Matsubara, Akihiro*; Ishii, Masahiro*; Jinno, Satoshi; Watanabe, Takahiro; Nishio, Tomohiro*; Ogawa, Yumi; Omae, Akiomi*; Kimura, Kenji; et al.
Dai-36-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.90 - 92, 2025/03
The JAEA-AMS-TONO facility at the Tono Geoscience Center, JAEA has three accelerator mass spectrometers. We report the present status of the JAEA-AMS-TONO.
Minamitani, Fumina; Nishio, Tomohiro*; Fujita, Natsuko; Maeta, Yusuke; Miyake, Masayasu; Matsubara, Akihiro*; Uno, Sadanori*; Omae, Akiomi*; Jinno, Satoshi; Watanabe, Takahiro
Dai-25-Kai AMS Shimpojiumu Hokokushu (Internet), 4 Pages, 2025/00
no abstracts in English
Jinno, Satoshi; Matsubara, Akihiro*; Fujita, Natsuko; Kimura, Kenji
Nuclear Instruments and Methods in Physics Research B, 557, p.165545_1 - 165545_4, 2024/12
Times Cited Count：1 Percentile：21.51(Instruments & Instrumentation)This study introduces the development of a downsized Accelerator Mass Spectrometry (AMS) system aiming to enhance accessibility and cost-effectiveness in radiocarbon analysis. The "crystal surface stripper method" is introduced as a solution to challenges in AMS downsizing, demonstrating effective ion detection with a smaller angular spread compared to conventional gas stripper methods. The experimental results provide insights into charge conversion capabilities, scattering angle broadening, and energy loss associated with surface scattering.
Fujita, Natsuko; Miyake, Masayasu; Matsubara, Akihiro*; Ishii, Masahiro*; Takahashi, Yuto*; Watanabe, Takahiro; Jinno, Satoshi; Nishio, Tomohiro*; Ogawa, Yumi; Kimura, Kenji; et al.
Dai-24-Kai AMS Shimpojiumu Hokokushu (Internet), 3 Pages, 2024/03
The JAEA-AMS-TONO facility at the Tono Geoscience Center, JAEA has three accelerator mass spectrometers. We report the present status of the JAEA-AMS-TONO.
Fujita, Natsuko; Miyake, Masayasu; Matsubara, Akihiro*; Ishii, Masahiro*; Watanabe, Takahiro; Jinno, Satoshi; Nishio, Tomohiro*; Ogawa, Yumi; Kimura, Kenji; Shimada, Akiomi; et al.
Dai-35-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.17 - 19, 2024/03
The JAEA-AMS-TONO facility at the Tono Geoscience Center, JAEA has three accelerator mass spectrometers. We report the present status of the JAEA-AMS-TONO.
Fujita, Natsuko; Matsubara, Akihiro*; Jinno, Satoshi; Kimura, Kenji
Hoshasen (Internet), 48(4), p.137 - 138, 2024/02
We have been developing a downsized AMS with a size of about 2 m 
2 m. This AMS is developed to demonstrate a new method of separating same-mass molecules, which are interfering nuclides during AMS measurement of carbon-14, using ion channeling.
-alkane mixed adsorbed film on counterion distribution and surface dilational viscoelasticity studied by total reflection XAFS and surface quasi-elastic light scatteringMatsubara, Satoshi*; Funatsu, Teruko*; Tanida, Hajime; Aratono, Makoto*; Imai, Yosuke*; Matsubara, Hiroki*
Langmuir, 39(22), p.7759 - 7765, 2023/06
Times Cited Count：4 Percentile：23.24(Chemistry, Multidisciplinary)Matsubara, Akihiro*; Fujita, Natsuko; Miyake, Masayasu; Ishii, Masahiro*; Watanabe, Takahiro; Kokubu, Yoko; Nishio, Tomohiro*; Ogawa, Yumi; Jinno, Satoshi; Kimura, Kenji; et al.
JAEA-Conf 2022-002, p.55 - 62, 2023/03
We report the present status of the JAEA-AMS-TONO. Particularly, the destructions of varistors used in the beamline equipment will be presented. The cause of the destruction as well as implementation of the safety measures are mentioned.
Fujita, Natsuko; Miyake, Masayasu; Matsubara, Akihiro*; Ishii, Masahiro*; Watanabe, Takahiro; Jinno, Satoshi; Nishio, Tomohiro*; Ogawa, Yumi; Yamamoto, Yusuke; Kimura, Kenji; et al.
Dai-23-Kai AMS Shimpojiumu Hokokushu, p.1 - 4, 2022/12
The JAEA-AMS-TONO facility at the Tono Geoscience Center, JAEA has three accelerator mass spectrometers. We report the present status of the JAEA-AMS-TONO.
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：2 Percentile：24.05(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.
Nakada, Akira; Nakano, Masanao; Kanai, Katsuta; Seya, Natsumi; Nishimura, Shusaku; Nemoto, Masashi; Tobita, Keiji; Futagawa, Kazuo; Yamada, Ryohei; Uchiyama, Rei; et al.
JAEA-Review 2021-062, 163 Pages, 2022/02
JAEA-Review-2021-062.pdf:2.87MB
Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of Japan Atomic Energy Agency, Chapter IV - Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged from the plant to the atmosphere and the sea during April 2020 to March 2021. In this report, some data include the influence of the accidental release from the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Co., Inc. (the trade name was changed to Tokyo Electric Power Company Holdings, Inc. on April 1, 2016) in March 2011. Appendices present comprehensive information, such as monitoring programs, monitoring methods, monitoring results and their trends, meteorological data and discharged radioactive wastes. In addition, the data which were influenced by the accidental release and exceeded the normal range of fluctuation in the monitoring, were evaluated.
Nakano, Masanao; Fujii, Tomoko; Nemoto, Masashi; Tobita, Keiji; Seya, Natsumi; Nishimura, Shusaku; Hosomi, Kenji; Nagaoka, Mika; Yokoyama, Hiroya; Matsubara, Natsumi; et al.
JAEA-Review 2020-069, 163 Pages, 2021/02
JAEA-Review-2020-069.pdf:4.78MB
Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of Japan Atomic Energy Agency, Chapter IV - Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged from the plant to the atmosphere and the sea during April 2019 to March 2020. In this report, some data include the influence of the accidental release from the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Co., Inc. (the trade name was changed to Tokyo Electric Power Company Holdings, Inc. on April 1, 2016) in March 2011. Appendices present comprehensive information, such as monitoring programs, monitoring methods, monitoring results and their trends, meteorological data and discharged radioactive wastes. In addition, the data which were influenced by the accidental release and exceeded the normal range of fluctuation in the monitoring, were evaluated.
Kato, Masaru*; Fujibayashi, Natsuki*; Abe, Daiki*; Matsubara, Naohiro*; Yasuda, Satoshi; Yagi, Ichizo*
ACS Catalysis, 11(4), p.2356 - 2365, 2021/02
Times Cited Count：59 Percentile：86.06(Chemistry, Physical)Fe-N-C oxygen reduction reaction catalyst is a key materials in polymer electrolyte fuel cell. However, the many Fe-N-C electrocatalysts still suffer from product selectivity due to the production of H
O as the byproduct. In this work, we synthesized an ORR electrocatalyst of Cu
, Fe, and N-doped carbon nanotubes. This heterobimetallic catalyst showed the selective four electron reduction of O to HO. Kinetic analysis of the electrocatalytic ORR and hydrogen peroxide reduction reaction in acidic media revealed that Cu, Fe-N-doped catalyst showed two orders of magnitude higher rate constants for the direct four electron reduction of O to HO than those for the two electron reduction of O to HO, whereas a monometallic Fe-N-doped catalyst showed the same order of magnitude, indicating that the heterometallic cooperativity had a drastic impact on the ORR kinetics.
F from 
O
?Tang, T. L.*; Uesaka, Tomohiro*; Kawase, Shoichiro; Beaumel, D.*; Dozono, Masanori*; Fujii, Toshihiko*; Fukuda, Naoki*; Fukunaga, Taku*; Galindo-Uribarri, A.*; Hwang, S. H.*; et al.
Physical Review Letters, 124(21), p.212502_1 - 212502_6, 2020/05
Times Cited Count：20 Percentile：71.03(Physics, Multidisciplinary)The structure of a neutron-rich F nucleus is investigated by a quasifree (
) knockout reaction. The sum of spectroscopic factors of 
orbital is found to be 1.0 
0.3. The result shows that the O core of F nucleus significantly differs from a free O nucleus, and the core consists of 35% O
, and 65% excited O. The result shows that the O core of F nucleus significantly differs from a free O nucleus. The result may infer that the addition of the 
proton considerably changes the neutron structure in F from that in O, which could be a possible mechanism responsible for the oxygen dripline anomaly.
Nakano, Masanao; Fujii, Tomoko; Nemoto, Masashi; Tobita, Keiji; Kono, Takahiko; Hosomi, Kenji; Nishimura, Shusaku; Matsubara, Natsumi; Maehara, Yushi; Narita, Ryosuke; et al.
JAEA-Review 2019-048, 165 Pages, 2020/03
JAEA-Review-2019-048.pdf:2.69MB
Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of Japan Atomic Energy Agency, Chapter IV - Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged from the plant to the atmosphere and the sea during April 2018 to March 2019. In this report, some data include the influence of the accidental release from the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Co., Inc. (the trade name was changed to Tokyo Electric Power Company Holdings, Inc. on April 1, 2016) in March 2011. Appendices present comprehensive information, such as monitoring programs, monitoring methods, monitoring results and their trends, meteorological data and discharged radioactive wastes. In addition, the data which were influenced by the accidental release and exceeded the normal range of fluctuation in the monitoring, were evaluated.
Nakano, Masanao; Fujita, Hiroki; Mizutani, Tomoko; Nemoto, Masashi; Tobita, Keiji; Kono, Takahiko; Hosomi, Kenji; Hokama, Tomonori; Nishimura, Tomohiro; Matsubara, Natsumi; et al.
JAEA-Review 2018-025, 171 Pages, 2019/02
JAEA-Review-2018-025.pdf:3.81MB
Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of Japan Atomic Energy Agency, Chapter IV - Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged from the plant to the atmosphere and the sea during April 2016 to March 2017. In this report, some data include the influence of the accidental release from the Fukushima Daiichi Nuclear Power Station of Electric Power Company Holdings, Inc. in March 2011. Appendices present comprehensive information, such as monitoring programs, monitoring methods, monitoring results and their trends, meteorological data and discharged radioactive wastes. In addition, the data which were influenced by the accidental release and were exceeded the normal range of fluctuation in the monitoring, were evaluated.
