Present status of the JAEA-AMS-TONO (2023FY)

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.

Validation of crystal surface scattering method for downsizing accelerator mass spectrometry

Jinno, Satoshi; Matsubara, Akihiro*; Fujita, Natsuko; Kimura, Kenji

Nuclear Instruments and Methods in Physics Research B, 557, p.165545_1 - 165545_4, 2024/12

https://doi.org/10.1016/j.nimb.2024.165545

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.

Present status of the JAEA-AMS-TONO (2023FY)

Fujita, Natsuko; Miyake, Masayasu; Matsubara, Akihiro*; Ishii, Masahiro*; Takahashi, Yuto*; Watanabe, Takahiro; Jinno, Satoshi; Nishio, Tomohiro*; Ogawa, Yumi; Kimura, Kenji; et al.

Dai-25-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.

Development of a downsized AMS system at JAEA-AMS-TONO

Fujita, Natsuko; Matsubara, Akihiro*; Jinno, Satoshi; Kimura, Kenji

Hoshasen (Internet), 48(4), p.137 - 138, 2024/02

https://doi.org/10.11470/houshasen.48.4_137

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.

Alloy design and characterization of a recrystallized FeCrAl-ODS cladding for accident-tolerant BWR fuels; An Overview of research activity in Japan

Ukai, Shigeharu; Sakamoto, Kan*; Otsuka, Satoshi; Yamashita, Shinichiro; Kimura, Akihiko*

Journal of Nuclear Materials, 583, p.154508_1 - 154508_24, 2023/09

https://doi.org/10.1016/j.jnucmat.2023.154508

Updates to the AMUR code for R-matrix analyses on heavy nuclei

Kunieda, Satoshi; Endo, Shunsuke; Kimura, Atsushi

EPJ Web of Conferences, 281, p.00017_1 - 00017_6, 2023/03

https://doi.org/10.1051/epjconf/202328100017

The AMUR code, which is based on the multi-channel/multi-level R-matrix theory, is under development for the cross-section evaluation with the covariance data in the resolved resonance energy region. Although, the code was initially designed for the analysis of the light-nuclei, the authors extended its capability toward the analysis of heavier nuclei by introducing the Reich-Moore approximation and the free-gas approximation for the Doppler broadening. In this work, we challenge a resonance analysis of neutron cross-section data measured in J-PARC/ANNRI with AMUR, in which the resolution functions and the double-bunching effects were taken into account inside the code. In this presentation, let us show results of resonance analysis on some of the J-PARC/ANNRI measurements together with covariance of the resonance parameters and cross-sections, for the first time. We also plan to discuss differences of correlation matrices among approximations of the R-matrix theory to understand physics underlying on the resonant reaction.

Superconducting fluctuation effect on epitaxially layered films of superconductor NbN and half-metallic Heusler alloy CoMnSi

Shigeta, Iduru*; Oku, Shuta*; Kubota, Takahide*; Kimura, Shojiro*; Seki, Takeshi*; Shinozaki, Bunju*; Awaji, Satoshi*; Takanashi, Koki; Hiroi, Masahiko*

AIP Advances (Internet), 13(2), p.025116_1 - 025116_5, 2023/02

https://doi.org/10.1063/9.0000584

Project for development of a downsized AMS system based on the surface stripper technique

Fujita, Natsuko; Matsubara, Akihiro; Kimura, Kenji; Jinno, Satoshi; Kokubu, Yoko

Nuclear Instruments and Methods in Physics Research B, 532, p.13 - 18, 2022/12

https://doi.org/10.1016/j.nimb.2022.09.011

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.

Effect of bacterial siderophore on cesium dissolution from biotite

Kimura, Tatsuki*; Fukutani, Satoshi*; Ikegami, Maiko*; Sakamoto, Fuminori; Kozai, Naofumi; Grambow, B.*; Yoneda, Minoru*

Chemosphere, 276, p.130121_1 - 130121_7, 2021/08

https://doi.org/10.1016/j.chemosphere.2021.130121

The adsorption of cesium (Cs) on biotite and dissolution of Cs from Cs-bearing biotite using a siderophore were investigated aiming to contribute to the elucidation of radiocesium migration mechanisms in the soil environment. Cs was adsorbed on a hardly weathered biotite powder sample. A siderophore was extracted and purified from the bacterial culture medium, and the purified siderophore was used in five consecutive dissolution experiments of the biotite samples. The major components of the biotite (Al, Fe, and Mg) were dissolved almost stoichiometrically, strongly suggesting that the siderophore selectively dissolves the broken edges of the biotite. The Cs adsorbed on the broken edges was dissolved rapidly as the siderophore dissolved the broken edges, and then, the Cs adsorbed on the outer planar surface of the biotite particles was slowly dissolved.

Quasifree neutron knockout reaction reveals a small -Orbital component in the Borromean nucleus B

Yang, Z. H.*; Kubota, Yuki*; Corsi, A.*; Yoshida, Kazuki; Sun, X.-X.*; Li, J. G.*; Kimura, Masaaki*; Michel, N.*; Ogata, Kazuyuki*; Yuan, C. X.*; et al.

Physical Review Letters, 126(8), p.082501_1 - 082501_8, 2021/02

AA2020-0819.pdf:1.29MB

https://doi.org/10.1103/PhysRevLett.126.082501

A quasifree (,) experiment was performed to study the structure of the Borromean nucleus B, which had long been considered to have a neutron halo. By analyzing the momentum distributions and exclusive cross sections, we obtained the spectroscopic factors for and orbitals, and a surprisingly small percentage of 9(2)% was determined for . Our finding of such a small component and the halo features reported in prior experiments can be explained by the deformed relativistic Hartree-Bogoliubov theory in continuum, revealing a definite but not dominant neutron halo in B. The present work gives the smallest - or -orbital component among known nuclei exhibiting halo features and implies that the dominant occupation of or orbitals is not a prerequisite for the occurrence of a neutron halo.