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Niwa, Masakazu; Shimada, Koji; Sueoka, Shigeru; Fujita, Natsuko; Yokoyama, Tatsunori; Ogita, Yasuhiro; Fukuda, Shoma; Nakajima, Toru; Kagami, Saya; Ogata, Manabu; et al.
JAEA-Review 2023-017, 27 Pages, 2023/10
This report is a plan of research and development (R&D) on geosphere stability for long-term isolation of high-level radioactive waste (HLW) in Japan Atomic Energy Agency (JAEA), in fiscal year 2023. The objectives and contents in fiscal year 2023 are described in detail based on the JAEA 4th Medium- and Long-term Plan (fiscal years 2022-2028). In addition, the background of this research is described from the necessity and the significance for site investigation and safety assessment, and the past progress. The plan framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques.
Niwa, Masakazu; Shimada, Koji; Sueoka, Shigeru; Ishihara, Takanori; Ogawa, Hiroki; Hakoiwa, Hiroaki; Watanabe, Tsuyoshi; Nishiyama, Nariaki; Yokoyama, Tatsunori; Ogata, Manabu; et al.
JAEA-Research 2023-005, 78 Pages, 2023/10
This annual report documents the progress of research and development (R&D) in the 1st fiscal year of the Japan Atomic Energy Agency 4th Medium- and Long-term Plan (fiscal years 2022-2028) to provide the scientific base for assessing geosphere stability for long-term isolation of high-level radioactive waste. The plan framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques. The current status of R&D activities with previous scientific and technological progress is summarized.
Kondo, Yosuke*; Achouri, N. L.*; Al Falou, H.*; Atar, L.*; Aumann, T.*; Baba, Hidetada*; Boretzky, K.*; Caesar, C.*; Calvet, D.*; Chae, H.*; et al.
Nature, 620(7976), p.965 - 970, 2023/08
no abstracts in English
Wang, H.*; Yasuda, Masahiro*; Kondo, Yosuke*; Nakamura, Takashi*; Tostevin, J. A.*; Ogata, Kazuyuki*; Otsuka, Takaharu*; Poves, A.*; Shimizu, Noritaka*; Yoshida, Kazuki; et al.
Physics Letters B, 843, p.138038_1 - 138038_9, 2023/08
Detailed -ray spectroscopy of the exotic neon isotope Ne has been performed using the one-neutron removal reaction from Ne. Based on an analysis of parallel momentum distributions, a level scheme with spin-parity assignments has been constructed for Ne and the negative-parity states are identified for the first time. The measured partial cross sections and momentum distributions reveal a significant intruder p-wave strength providing evidence of the breakdown of the N = 20 and N = 28 shell gaps. Only a weak, possible f-wave strength was observed to bound final states. Large-scale shell-model calculations with different effective interactions do not reproduce the large p-wave and small f-wave strength observed experimentally, indicating an ongoing challenge for a complete theoretical description of the transition into the island of inversion along the Ne isotopic chain.
Ogata, Misa*; Okawa, Hirotada*; Fujisawa, Kotaro*; Yasutake, Nobutoshi; Yamamoto, Yu*; Yamada, Shoichi*
Monthly Notices of the Royal Astronomical Society, 521(2), p.2561 - 2576, 2023/05
Okawa, Hirotada*; Fujisawa, Kotaro*; Yasutake, Nobutoshi; Ogata, Misa*; Yamamoto, Yu*; Yamada, Shoichi*
Monthly Notices of the Royal Astronomical Society, 520(1), p.24 - 43, 2023/03
Sasao, Eiji; Ishimaru, Tsuneari; Niwa, Masakazu; Shimada, Akiomi; Shimada, Koji; Watanabe, Takahiro; Sueoka, Shigeru; Yokoyama, Tatsunori; Fujita, Natsuko; Ogita, Yasuhiro; et al.
JAEA-Review 2022-022, 29 Pages, 2022/09
This report is a plan of research and development (R&D) on geosphere stability for long-term isolation of high-level radioactive waste (HLW) in Japan Atomic Energy Agency (JAEA), in fiscal year 2022. The objectives and contents in fiscal year 2022 are described in detail based on the JAEA 4th Medium- and Long-term Plan (fiscal years 2022-2028). In addition, the background of this research is described from the necessity and the significance for site investigation and safety assessment, and the past progress. The plan framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques
Nakajima, Toru; Fukuda, Shoma; Ogata, Manabu; Sueoka, Shigeru
Fisshion, Torakku Nyusureta, (34), p.25 - 26, 2021/12
The 17th International Conference on Thermochronology (Thermo2021) was held on September 12-17, 2021 at the Eldorado Resort in downtown Santa Fe, New Mexico, USA. Due to the social situation and the spread of the COVID-19, the event had been postponed. In this paper, I report on the circumstances surrounding our participation in the conference, the contents and trends of the presentations made at the conference, and the tasks for the 2023 and 2025 conferences.
Ishimaru, Tsuneari; Ogata, Nobuhisa; Kokubu, Yoko; Shimada, Koji; Niwa, Masakazu; Shimada, Akiomi; Watanabe, Takahiro; Sueoka, Shigeru; Yokoyama, Tatsunori; Fujita, Natsuko; et al.
JAEA-Research 2021-007, 65 Pages, 2021/10
This annual report documents the progress of research and development (R&D) in the 6th fiscal year during the JAEA 3rd Mid- and Long-term Plan (fiscal years 2015-2021) to provide the scientific base for assessing geosphere stability for long-term isolation of the high-level radioactive waste. The planned framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques. The current status of R&D activities with previous scientific and technological progress is summarized.
Ishimaru, Tsuneari; Kokubu, Yoko; Shimada, Koji; Shimada, Akiomi; Niwa, Masakazu; Watanabe, Takahiro; Sueoka, Shigeru; Yokoyama, Tatsunori; Fujita, Natsuko; Ogita, Yasuhiro; et al.
JAEA-Review 2021-012, 48 Pages, 2021/08
This report is a plan of research and development (R&D) on geosphere stability for long-term isolation of high-level radioactive waste (HLW) in Japan Atomic Energy Agency (JAEA), in fiscal year 2021. The objectives and contents in fiscal year 2021 are described in detail based on the JAEA 3rd Medium- and Long-term Plan (fiscal years 2015-2021). In addition, the background of this research is described from the necessity and the significance for site investigation and safety assessment, and the past progress. The plan framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques.
Mishima, Seiki*; Ogata, Sho*; Inui, Toru*; Yasuhara, Hideaki*; Kishida, Kiyoshi*; Aoyagi, Kazuhei
Dai-15-Kai Iwa No Rikigaku Kokunai Shimpojiumu Koen Rombunshu (Internet), p.215 - 220, 2021/01
When the durability of the geological repository of high-level radioactive waste is evaluated, understanding the cracking behavior within the crystalline/sedimentary rocks during excavation of waste disposal cavities is important. In this study, we performed a numerical analysis that expressed the tunnel excavation carried out 350 m underground at the Horonobe Underground Research Center of the Japan Atomic Energy Agency. Simulated results are agreement with actual trends of fracture propagation, and the measured horizontal convergence of the tunnel was reproduced by the numerical analysis relatively well.
Tanaka, Junki*; Yang, Z.*; Typel, S.*; Adachi, Satoshi*; Bai, S.*; van Beek, P.*; Beaumel, D.*; Fujikawa, Yuki*; Han, J.*; Heil, S.*; et al.
Science, 371(6526), p.260 - 264, 2021/01
Times Cited Count:30 Percentile:99.14(Multidisciplinary Sciences)By employing quasi-free -cluster-knockout reactions, we obtained direct experimental evidence for the formation of clusters at the surface of neutron-rich tin isotopes. The observed monotonous decrease of the reaction cross sections with increasing mass number, in excellent agreement with the theoretical prediction, implies a tight interplay between -cluster formation and the neutron skin.
Ishimaru, Tsuneari; Ogata, Nobuhisa; Shimada, Koji; Kokubu, Yoko; Niwa, Masakazu; Asamori, Koichi; Watanabe, Takahiro; Sueoka, Shigeru; Komatsu, Tetsuya; Yokoyama, Tatsunori; et al.
JAEA-Review 2020-010, 46 Pages, 2020/07
This report is a plan of research and development (R&D) on geosphere stability for long-term isolation of high-level radioactive waste (HLW) in Japan Atomic Energy Agency (JAEA), in fiscal year 2020. The objectives and contents in fiscal year 2020 are described in detail based on the JAEA 3rd Medium- and Long-term Plan (fiscal years 2015-2021). In addition, the background of this research is described from the necessity and the significance for site investigation and safety assessment, and the past progress. The plan framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques.
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:14 Percentile:74.77(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.
Ogata, Sho*; Yasuhara, Hideaki*; Aoyagi, Kazuhei; Kishida, Kiyoshi*
Proceedings of 53rd US Rock Mechanics/Geomechanics Symposium (USB Flash Drive), 6 Pages, 2019/06
Minato, Futoshi; Iwamoto, Osamu; Minomo, Kosho*; Ogata, Kazuyuki*; Iwamoto, Nobuyuki; Kunieda, Satoshi; Furutachi, Naoya
EPJ Web of Conferences, 146, p.12032_1 - 12032_4, 2017/09
Times Cited Count:1 Percentile:61.28Phenomenological optical potential is known to be able to describe the elastic scattering process. It is applied widely to the nuclear data evaluation of the cross section. Many kinds of the optical potential have been studied so far. However, the parameters in the phenomenological optical potentials are determined so as to reproduce existing experimental data, so that use of it for unmeasured nuclei such as neutron-rich nuclei is not necessarily reliable. Recently, a new optical potential derived from the microscopic effective reaction theory (MERT) was proposed. Since the formulation of MERT is based on the NN effective interaction, any parameterizations in the optical potential aren't needed. Therefore, it is capable of calculating nuclei whose scattering cross section isn't measured. We incorporate the optical potentials of MERT in code CCONE and start nuclear data evaluation of several nuclei. In this work, we discuss difference of cross sections evaluated by MERT's optical potentials and conventional phenomenological ones.
Fukui, Tokuro; Ogata, Kazuyuki*; Minomo, Kosho*; Yahiro, Masanobu*
JPS Conference Proceedings (Internet), 14, p.020513_1 - 020513_3, 2017/02
Times Cited Count:0 Percentile:0.03Lee, J.*; Liu, H.*; Doornenbal, P.*; Kimura, Masaaki*; Minomo, Kosho*; Ogata, Kazuyuki*; Utsuno, Yutaka; Aoi, Nori*; Li, K.*; Matsushita, Masafumi*; et al.
Progress of Theoretical and Experimental Physics (Internet), 2016(8), p.083D01_1 - 083D01_7, 2016/08
Times Cited Count:6 Percentile:44.94(Physics, Multidisciplinary)no abstracts in English
Hayakawa, Takehito; Shizuma, Toshiyuki; Miyamoto, Shuji*; Amano, Sho*; Takemoto, Akinori*; Yamaguchi, Masashi*; Horikawa, Ken*; Akimune, Hidetoshi*; Chiba, Satoshi*; Ogata, Kazuyuki*; et al.
Physical Review C, 93(4), p.044313_1 - 044313_4, 2016/04
Times Cited Count:7 Percentile:49.44(Physics, Nuclear)We have measured the azimuthal anisotropy of neutrons emitted from the Fe(, n)Fe reaction with a linearly polarized ray beam generated by laser Compton scattering at NewSUBARU. Neutron yields at the polar angle of 90 have been measured as a function of the azimuthal angle between the detector and the linear polarization plane of the ray beam. The azimuthal anisotropy of neutrons measured at seven angles has been well reproduced using a theoretically predicted function of + cos(2).
Nakayama, Shinsuke*; Araki, Shohei*; Watanabe, Yukinobu*; Iwamoto, Osamu; Ye, T.*; Ogata, Kazuyuki*
Energy Procedia, 71, p.219 - 227, 2015/05
Times Cited Count:10 Percentile:98.41A calculation code system for evaluation of deuteron nuclear data is extended so that the stripping reaction to bound states in the residual nucleus can be taken into account properly using a conventional zero-range DWBA approach. The code system is applied to deuteron induced-reactions on Al for incident energies up to 100 MeV. It is found that the spectroscopic factors derived from the present DWBA analysis have incident energy dependence. The calculation using the extended code system reproduced experimental double-differential (d,xp) cross sections at 25.5, 56, and 100 MeV, and production cross sections of Al in the incident energy range from the threshold to 20 MeV.