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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.
Osawa, Takahito; Nagasawa, Shunsaku*; Ninomiya, Kazuhiko*; Takahashi, Tadayuki*; Nakamura, Tomoki*; Wada, Taiga*; Taniguchi, Akihiro*; Umegaki, Izumi*; Kubo, Kenya*; Terada, Kentaro*; et al.
ACS Earth and Space Chemistry (Internet), 7(4), p.699 - 711, 2023/04
Times Cited Count：4 Percentile：93.95(Chemistry, Multidisciplinary)The concentrations of carbon and other major elements in asteroid samples provide very important information on the birth of life on the Earth and the solar-system evolution. Elemental analysis using muonic X-rays is one of the best analytical methods to determine the elemental composition of solid materials, and notably, is the only method to determine the concentration of light elements in bulk samples in a non-destructive manner. We developed a new analysis system using muonic X-rays to measure the concentrations of carbon and other major elements in precious and expectedly tiny samples recovered from the asteroid Ryugu by spacecraft Hayabusa2. Here we report the development process of the system in 4 stages and their system configurations, The analysis system is composed of a stainless-steel analysis chamber, an acrylic glove box for manipulating asteroid samples in a clean environment, and Ge semiconductor detectors arranged to surround the analysis chamber. The performance of the analysis system, including the background level, which is crucial for the measurement, was greatly improved from the first stage to the later ones. Our feasibility study showed that the latest model of our muonic X-ray analysis system is capable of determining the carbon concentration in Hayabusa2's sample model with an uncertainty of less than 10 percent in a 6-day measurement.
Kumagai, Tomohisa*; Miura, Yasufumi*; Miura, Naoki*; Marie, S.*; Almahdi, R.*; Mano, Akihiro; Li, Y.; Katsuyama, Jinya; Wada, Yoshitaka*; Hwang, J.-H.*; et al.
Journal of Pressure Vessel Technology, 144(1), p.011509_1 - 011509_18, 2022/02
Times Cited Count：1 Percentile：20.34(Engineering, Mechanical)To predict fracture behavior for ductile materials, some ductile fracture simulation methods different from classical approaches have been investigated based on appropriate models of ductile fracture. For the future use of the methods to overcome restrictions of classical approaches, the applicability to the actual components is of concern. In this study, two benchmark problems on the fracture tests supposing actual components were provided to investigate prediction ability of simulation methods containing parameter decisions. One was the circumferentially through-wall and surface cracked pipes subjected to monotonic bending, and the other was the circumferentially through-wall cracked pipes subjected to cyclic bending. Participants predicted the ductile crack propagation behavior by their own approaches, including FEM employed GTN yielding function with void ratio criterion, are FEM employed GTN yielding function, FEM with fracture strain or energy criterion modified by stress triaxiality, XFEM with J or delta J criterion, FEM with stress triaxiality and plastic strain based ductile crack propagation using FEM, and elastic-plastic peridynamics. Both the deformation and the crack propagation behaviors for monotonic bending were well reproduced, while few participants reproduced those for cyclic bending. To reproduce pipe deformation and fracture behaviors, most of groups needed parameters which were determined toreproduce pipe deformation and fracture behaviors in benchmark problems themselves and it is still difficult to reproduce them by using parameters only from basic materials tests.
Be; Particle size distribution and chemical composition of Be-carrying aerosols in the atmosphere in JapanNarazaki, Yukinori*; Sakoda, Akihiro; Takahashi, Shunta*; Momoshima, Noriyuki*
Journal of Environmental Radioactivity, 237, p.106690_1 - 106690_7, 2021/10
Times Cited Count：3 Percentile：20.86(Environmental Sciences)The particle size distributions of airborne aerosols with Be were measured using cascade impactors at Dazaifu, a city in western Japan, in 2018 to observe their seasonal variation. Be was found to be attached to aerosols with a particle size of less than 2.1 
m; in general, particles sized 0.43-0.65 m had the highest Be activity concentrations. The activity median aerodynamic diameter (AMAD) of Be was in the range of 0.39-0.52 m, which is the size range of particles that can reach human alveoli, and had an annual mean of 0.43
0.035 m. The activity concentrations of Be were significantly lower in summer, which affected its activity concentrations in the particle size distributions of Be. The particle size distribution of Be-carrying aerosols was also affected by that of the aerosol particles in the atmosphere. Finally, findings suggest that Be was mainly attached to sulfate aerosols (particularly ammonium sulfate aerosols).
Sr in cattle bone and tooth samples by inductively coupled plasma mass spectrometryKoarai, Kazuma; Matsueda, Makoto; Aoki, Jo; Yanagisawa, Kayo*; Terashima, Motoki; Fujiwara, Kenso; Kino, Yasushi*; Oka, Toshitaka; Takahashi, Atsushi*; Suzuki, Toshihiko*; et al.
Journal of Analytical Atomic Spectrometry, 36(8), p.1678 - 1682, 2021/08
Times Cited Count：5 Percentile：55.72(Chemistry, Analytical)Rapid analysis of Sr in bone and tooth samples of cattle were achieved by an inductively coupled plasma mass spectrometry (ICP-MS) coupled with mass shift and solid phase extraction techniques. Limit of detection (LOD) in the ICP-MS measurement of 0.1 g samples was lower than that of the radioactivity measurement. Analytical time of the ICP-MS method was reduced from 20 days to 11 hours, compared with the radiometric method. Therefore, the ICP-MS method can be rapid and useful procedure of Sr in small bone and tooth samples derived from terrestrial animals.
Miao, P.*; Tan, Z.*; Lee, S. H.*; Ishikawa, Yoshihisa*; Torii, Shuki*; Yonemura, Masao*; Koda, Akihiro*; Komatsu, Kazuki*; Machida, Shinichi*; Sano, Asami; et al.
Physical Review B, 103(9), p.094302_1 - 094302_18, 2021/03
Times Cited Count：2 Percentile：17.84(Materials Science, Multidisciplinary)The layered perovskite PrBaCo
O
demonstrates a strong negative thermal expansion (NTE) which holds potential for being fabricated into composites with zero thermal expansion. The NTE was found to be intimately associated with the spontaneous magnetic ordering, known as magneto-volume effect (MVE). Here we report with compelling evidences that the continuous-like MVE in PrBaCoO is intrinsically of discontinuous character, originating from an magnetoelectric transition from an antiferromagnetic insulating large-volume (AFILV) phase to a ferromagnetic less-insulating small-volume (FLISV) phase. Furthermore, the magnetoelectric effect (ME) shows high sensitivity to multiple external stimuli such as temperature, carrier doping, hydrostatic pressure, magnetic field etc. In contrast to the well-known ME such as colossal magnetoresistance and multi-ferroic effect which involve symmetry breaking of crystal structure, the ME in the cobaltite is purely isostructural. Our discovery provides a new path way to realizing the ME as well as the NTE, which may find applications in new techniques.
CsCl-supplemented diet to evaluate the effects of low dose-rate exposureTanaka, Sota; Kinouchi, Tadatoshi*; Fujii, Tsuguru*; Imanaka, Tetsuji*; Takahashi, Tomoyuki*; Fukutani, Satoshi*; Maki, Daisuke*; Notomi, Akihiro*; Takahashi, Sentaro*
Scientific Reports (Internet), 10, p.16055_1 - 16055_7, 2020/09
Times Cited Count：7 Percentile：49.75(Multidisciplinary Sciences)Since the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, morphological abnormalities of the lepidopteran insects have been reported. However, it is unclear whether the abnormalities were caused directly by radiation because they did not study on absorbed dose and dose-effect relationship. In this study, we conducted an internal exposure experiment on silkworm using CsCl-supplemented artificial diet and estimated the absorbed dose to evaluate the morphological abnormalities in silkworm. The ratio of wing to whole body of pupae was compared between the CsCl-exposured and control groups and no significant differences were observed between the groups. This result suggest that morphological abnormalities in lepidopterans are unlikely due to direct radiation effects from Cs contamination after the FDNPP accident.
Wu, H.-Y.*; Takahashi, Shigeo*; Miyamura, Hiroko; Ozahata, Satoshi*; Nakao, Akihiro*
Electronic Imaging, 2017(1), p.118 - 130, 2017/01
Extracting hierarchical structures from networks provides us with an effective means of visualizing them, especially when they contain complicated node connectivities such as those in traffic and distributed networks. This paper presents an algorithm for inferring such partial orders by optimizing the network hierarchies along flow paths that are given as input. We study several network examples to demonstrate the feasibility of the proposed approach including course dependency charts, railway networks, and P2P networks.
Wu, H.-Y.*; Takahashi, Shigeo*; Miyamura, Hiroko; Ozahata, Satoshi*; Nakao, Akihiro*
Journal of Imaging Science and Technology, 60(6), p.060407_1 - 060407_13, 2016/11
Times Cited Count：0 Percentile：0.02(Imaging Science & Photographic Technology)Extracting hierarchical structures from networks provides us with an effective means of visualizing them, especially when they contain complicated node connectivities such as those in traffic and distributed networks. This paper presents an algorithm for inferring such partial orders by optimizing the network hierarchies along flow paths that are given as input. We study several network examples to demonstrate the feasibility of the proposed approach including course dependency charts, railway networks, and P2P networks.
Nakamura, Shoji; Terada, Kazushi; Shibahara, Yuji*; Uehara, Akihiro*; Fujii, Toshiyuki*; Sano, Tadafumi*; Takahashi, Yoshiyuki*; Hori, Junichi*
KURRI Progress Report 2015, P. 67, 2016/08
The activation measurements of Np-237 were performed with neutron sources at KURRI-Linac. It was found that activation measurements supported the evaluated cross-section data of JENDL-4.0.
Terunuma, Akihiro; Mimura, Ryuji; Nagashima, Hisao; Aoyagi, Yoshitaka; Hirokawa, Katsunori*; Uta, Masato; Ishimori, Yuu; Kuwabara, Jun; Okamoto, Hisato; Kimura, Yasuhisa; et al.
JAEA-Review 2016-008, 98 Pages, 2016/07
JAEA-Review-2016-008.pdf:11.73MB
Japan Atomic Energy Agency formulated the plan to achieve the medium-term target in the period of April 2010 to March 2015(hereinafter referred to as "the second medium-term plan"). JAEA determined the plan for the business operations of each year (hereinafter referred to as "the year plan"). This report is that the Sector of Decommissioning and Radioactive Waste Management has summarized the results of the decommissioning technology development and decommissioning of nuclear facilities which were carried out in the second medium-term plan.
pellets for Mo-99 production, 2Nishikata, Kaori; Ishida, Takuya; Yonekawa, Minoru; Kato, Yoshiaki; Kurosawa, Makoto; Kimura, Akihiro; Matsui, Yoshinori; Tsuchiya, Kunihiko; Sano, Tadafumi*; Fujihara, Yasuyuki*; et al.
KURRI Progress Report 2014, P. 109, 2015/07
As one of effective applications of the Japan Materials Testing Reactor (JMTR), JAEA has a plan to produce 
Mo by (n,
) method ((n,)Mo production), a parent nuclide of 
Tc. In this study, preliminary irradiation test was carried out with the high-density molybdenum trioxide (MoO) pellets in the hydraulic conveyer (HYD) of the Kyoto University Research Reactor (KUR) and the Tc solution extracted from Mo was evaluated. After the irradiation test of the high-density MoO pellets in the KUR, Tc was extracted from the Mo solution and the recovery rate of Tc achieved the target values. The Tc solution also got the value that satisfied the standard value for Tc radiopharmaceutical products by the solvent extraction method.
Takasaki, Koji; Yasumune, Takashi; Onishi, Takashi; Nakamura, Keisuke; Ishimi, Akihiro; Ito, Chikara; Osaka, Masahiko; Ono, Masashi*; Hatakeyama, Shuichi*; Takahashi, Hiroyuki*; et al.
JAEA-Research 2013-043, 33 Pages, 2014/01
JAEA-Research-2013-043.pdf:13.81MB
In the Fukushima Daiichi Nuclear Power Plant, it is assumed that the core fuels melted partially or wholly, and the normal technique of accounting for a fuel assembly is not applicable. Therefore, it is necessary to develop the transparent and rational technique of accounting in the process of collection and storage of fuel debris. In this research, an application of the superconducting phase Transition Edge Sensor microcalorimeter (TES microcalorimeter) is studied for the accounting of nuclear materials in the fuel debris. It is expected that the detailed information of nuclear materials and fission products in fuel debris is obtained by using a high-resolution characteristic of TES microcalorimeter. In this report, the principle of TES microcalorimeter, the measurement experiment using TES in JAEA, and the simulated calculation using the EGS5 code system are summarized.
Miyamura, Hiroko; Hu, H.-Y.*; Yoshida, Masahiro*; Ozahata, Satoshi*; Nakao, Akihiro*; Takahashi, Shigeo*
Shingaku Giho, 112(463), p.577 - 582, 2013/03
This report presents a method for visualizing scale-free networks including Overlay networks as an typical example. Visualizing large-scale and complicated networks such as social networks has recently been very popular while conventional network visualization techniques cannot allow us to understand the topological structure of the scale-free networks. This is because the vertex degrees vary at an exponential rate in the scale-free network and thus special attention should be given when visualizing the network connectivity and analyzing the network traffic there. In this report, we employ the hierarchical representation of the scale-free network by referring to their vertex degrees and autonomous system relationships, so that we can clearly visualize the topological structure of the network in 3D space and retrieve the traffic paths over the network.
Tsuji, Tomoyuki; Kameo, Yutaka; Sakai, Akihiro; Hoshi, Akiko; Takahashi, Kuniaki
JAEA-Technology 2012-045, 37 Pages, 2013/02
JAEA-Technology-2012-045.pdf:2.43MB
It is necessary to establish practical evaluation methods to determine radioactivity concentrations of the important nuclides for safety assessment on disposal of radioactive wastes in order to dispose of low-level radioactive wastes generated from various nuclear facilities in JAEA. In this report, the practical evaluation methods such as the scaling factor method for JPDR facilities have been studied for disposal of the low-level radioactive wastes generated from nuclear reactor facilities in JAEA.
Hoshina, Hiroyuki; Kasai, Noboru; Shibata, Takuya*; Aketagawa, Yasushi*; Takahashi, Makikatsu*; Yoshii, Akihiro*; Tsunoda, Yasuhiko*; Seko, Noriaki
Radiation Physics and Chemistry, 81(8), p.1033 - 1035, 2012/08
Times Cited Count：4 Percentile：31.96(Chemistry, Physical)Tsuji, Tomoyuki; Kameo, Yutaka; Sakai, Akihiro; Amazawa, Hiroya; Takahashi, Kuniaki
JAEA-Technology 2011-028, 66 Pages, 2011/11
JAEA-Technology-2011-028.pdf:3.16MB
In order to dispose of low-level radioactive wastes generated from various nuclear facilities in JAEA, we need to establish practical evaluation methods to determine radioactivity concentrations of the important nuclides for safety assessment on disposal of radioactive wastes. In this report, we have studied on establishing the practical evaluation methods such as the scaling factor method for bituminized products generated at Nuclear Science Research Institute and also summarized subjects for establishment of the practical evaluation methods for the bituminized products.
Hoshi, Akiko; Tsuji, Tomoyuki; Tanaka, Kiwamu; Yasuda, Mari; Watanabe, Koichi; Sakai, Akihiro; Kameo, Yutaka; Kogure, Hiroto; Higuchi, Hidekazu; Takahashi, Kuniaki
JAEA-Data/Code 2011-011, 31 Pages, 2011/10
JAEA-Data-Code-2011-011.pdf:1.7MB
Simple and rapid methods to evaluate the radioactivity concentrations are required to be established for the near surface disposal of radioactive wastes generated from research facilities at Japan Atomic Energy Agency. In order to establish the methods to evaluate the radioactivity concentrations of miscellaneous solid wastes generated from research and testing reactors, we collected and analyzed samples from miscellaneous solid wastes generated by the decommissioning of JPDR (Japan Power Demonstration Reactor). In the present paper, we summarized data (262 data) about the radioactivity concentrations of the 7 important nuclides (
H, 
C, 
Co, 
Ni, 
Ni, Sr, Cs) which accumulated by the analysis.
Shiraki, Fumiya*; Yoshikawa, Taeko*; Oshima, Akihiro*; Oshima, Yuji*; Takasawa, Yuya*; Fukutake, Naoyuki*; Oyama, Tomoko*; Urakawa, Tatsuya*; Fujita, Hajime*; Takahashi, Tomohiro*; et al.
Nuclear Instruments and Methods in Physics Research B, 269(15), p.1777 - 1781, 2011/08
Times Cited Count：8 Percentile：53.37(Instruments & Instrumentation)The graded energy deposition of heavy ion beam irradiation to polymeric materials was utilized to synthesize a novel proton exchange membrane (PEM) with the graded density of sulfonic acid groups toward the thickness direction. Stacked Poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP) films were irradiated by Xe
ion beam with the energy of 6 MeV/u under a vacuum condition. Irradiated films were grafted with styrene monomer and then sulfonated. The membrane electrode assembly (MEA) fabricated by the function graded PEM showed improved fuel cell performance in terms of voltage stability. It was expected that the function-graded PEM could control the graded concentration of sulfonic acid groups in PEM.
Okubo, Satoshi*; Takahashi, Tomohiro*; Takasawa, Yuya*; Gowa, Tomoko*; Sasaki, Takashi*; Nagasawa, Naotsugu; Tamada, Masao; Oshima, Akihiro*; Tagawa, Seiichi*; Washio, Masakazu*
Journal of Photopolymer Science and Technology, 23(3), p.393 - 397, 2010/11
Times Cited Count：4 Percentile：13.82(Polymer Science)Microfabrication of biodegradable polymers such as poly(butylene succinate-
-adipate) (PBSA) and poly(
-caprolactone) (PCL) were demonstrated using focused ion beam (FIB) with maskless direct etching. As the result, the micro structures of PBSA and PCL were obtained. The etching depth of both PBSA and PCL were increased with increasing FIB fluence, and the etching rates were estimated to be about 1.3 
10
m/(ions cm
) and 1.2 10 m/(ions cm), respectively. Moreover, very thin films of PBSA and PCL were made by spin-coating method. The thicknesses of the spin-coated samples were about 200 nm, and the surface roughness was less than 10 nm (RMS). The fine structures such as micro-gear of PBSA and PCL were obtained without solid debris. The line width of the fabricated structure was about 250 nm.
