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OKondo, 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
Times Cited Count：6 Percentile：93.26(Multidisciplinary Sciences)no abstracts in English
Ne at the transition into the island of inversion; Detailed structure study of NeWang, 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
Times Cited Count：2 Percentile：83.53(Astronomy & Astrophysics)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.
Yamamoto, Kazami; Kinsho, Michikazu; Hayashi, Naoki; Saha, P. K.; Tamura, Fumihiko; Yamamoto, Masanobu; Tani, Norio; Takayanagi, Tomohiro; Kamiya, Junichiro; Shobuda, Yoshihiro; et al.
Journal of Nuclear Science and Technology, 59(9), p.1174 - 1205, 2022/09
Times Cited Count：5 Percentile：87.42(Nuclear Science & Technology)In the Japan Proton Accelerator Research Complex, the purpose of the 3 GeV rapid cycling synchrotron (RCS) is to accelerate a 1 MW, high-intensity proton beam. To achieve beam operation at a repetition rate of 25 Hz at high intensities, the RCS was elaborately designed. After starting the RCS operation, we carefully verified the validity of its design and made certain improvements to establish a reliable operation at higher power as possible. Consequently, we demonstrated beam operation at a high power, namely, 1 MW. We then summarized the design, actual performance, and improvements of the RCS to achieve a 1 MW beam.
Mo/
Tc generator by (n, ) method, 4Fujita, Yoshitaka; Seki, Misaki; Ngo, M. C.*; Do, T. M. D.*; Hu, X.*; Yang, Y.*; Takeuchi, Tomoaki; Nakano, Hiroko; Fujihara, Yasuyuki*; Yoshinaga, Hisao*; et al.
KURNS Progress Report 2021, P. 118, 2022/07
no abstracts in English
Seki, Misaki; Fujita, Yoshitaka; Fujihara, Yasuyuki*; Zhang, J.*; Yoshinaga, Hisao*; Sano, Tadafumi*; Hori, Junichi*; Nagata, Hiroshi; Otsuka, Kaoru; Omori, Takazumi; et al.
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 29(1), p.2 - 9, 2022/06
no abstracts in English
Al
GaO
scintillators by gamma-ray-induced positron annihilation lifetime spectroscopyFujimori, Kosuke*; Kitaura, Mamoru*; Taira, Yoshitaka*; Fujimoto, Masaki*; Zen, H.*; Watanabe, Shinta*; Kamada, Kei*; Okano, Yasuaki*; Kato, Masahiro*; Hosaka, Masahito*; et al.
Applied Physics Express, 13(8), p.085505_1 - 085505_4, 2020/08
Times Cited Count：5 Percentile：32.24(Physics, Applied)To clarify the existence of cation vacancies in Ce-doped GdAlGaO (Ce:GAGG) scintillators, we performed gamma-ray-induced positron annihilation lifetime spectroscopy (GiPALS). GiPAL spectra of GAGG and Ce:GAGG comprised two exponential decay components, which were assigned to positron annihilation at bulk and defect states. By an analogy with Ce:YAl
O, the defect-related component was attributed to Al/Ga-O divacancy complexes. This component was weaker for Ce, Mg:GAGG, which correlated with the suppression of shallow electron traps responsible for phosphorescence. Oxygen vacancies were charge compensators for Al/Ga vacancies. The lifetime of the defect-related component was significantly changed by Mg co-doping. This was understood by considering aggregates of Mg
ions at Al/Ga sites with oxygen vacancies, which resulted in the formation of vacancy clusters.
Seki, Misaki; Ishikawa, Koji*; Sano, Tadafumi*; Nagata, Hiroshi; Otsuka, Kaoru; Omori, Takazumi; Hanakawa, Hiroki; Ide, Hiroshi; Tsuchiya, Kunihiko; Fujihara, Yasuyuki*; et al.
KURNS Progress Report 2019, P. 279, 2020/08
no abstracts in English
Seki, Misaki; Ishikawa, Koji*; Nagata, Hiroshi; Otsuka, Kaoru; Omori, Takazumi; Hanakawa, Hiroki; Ide, Hiroshi; Tsuchiya, Kunihiko; Sano, Tadafumi*; Fujihara, Yasuyuki*; et al.
KURNS Progress Report 2018, P. 257, 2019/08
no abstracts in English
Shirai, Nobutoshi; Miura, Yasushi; Tachibana, Ikuya; Omori, Satoru; Wake, Junichi; Fukuda, Kazuhito; Nakano, Takafumi; Nagasato, Yoshihiko
JAEA-Technology 2016-007, 951 Pages, 2016/07
JAEA-Technology-2016-007-01.pdf:11.93MBJAEA-Technology-2016-007-02.pdf:4.7MB
The periodic safety review of TRP is to confirm the safety activities and get effective additional measures the facility safety and its reliability. We implemented 4 items; for (1) evaluation of safety activity implementation, we confirmed we are adequately expanding its safety activities by the necessary documents and schemes. For (2) evaluation of status of safety activities reflecting the latest technical knowledges, we confirmed we reflect latest knowledges for improvement of safety and reliability. For (3) technical evaluation about aging degradation, we can keep the safety of the facilities important to safety and the sea discharge line, under assumption of the present maintenance, because of "focuses for aging degradation". For (4) planning measures about a 10-years-plan that the operator shall implement to keep the facility condition, by the technical evaluation, we found no additional safety plans into maintenance strategies.
Yoshida, Masafumi; Hanada, Masaya; Kojima, Atsushi; Kashiwagi, Mieko; Umeda, Naotaka; Hiratsuka, Junichi; Ichikawa, Masahiro; Watanabe, Kazuhiro; Grisham, L. R.*; Tsumori, Katsuyoshi*; et al.
Review of Scientific Instruments, 87(2), p.02B144_1 - 02B144_4, 2016/02
Times Cited Count：9 Percentile：42.47(Instruments & Instrumentation)Time evolution of spatial profile of negative ion production during an initial conditioning phase has been experimentally investigated in the JT-60 negative ion source. Up to 0.4 g Cs injection, there is no enhancement of the negative ion production and no observation of the Cs emission signal in the source, suggesting the injected Cs is mainly deposited on the water-cooled wall near the nozzle. After 0.4 g Cs injection, enhancement of the negative ion production appeared only at the central segment of the PG. The calculation of the Cs neutral/ion trajectories implied that a part of Cs was ionized near the nozzle and was transported to this area. The expansion of the area of the surface production was saturated after ~2 g Cs injection corresponding to 6000 s discharge time. From the results, it is found that Cs ionization and its transport plays an important role for the negative ion production.
He/
He ratios along a high strain rate zone, central JapanUmeda, Koji; Kusano, Tomohiro; Ninomiya, Atsushi*; Asamori, Koichi; Nakajima, Junichi*
Journal of Asian Earth Sciences, 73, p.95 - 102, 2013/09
Times Cited Count：4 Percentile：12.21(Geosciences, Multidisciplinary)A linear zone with high strain rates along the Japan Sea coast, the Niigata-Kobe Tectonic Zone (NKTZ), is considered to be associated with rheological heterogeneities in the lower crust and/or upper mantle. Helium isotope variations along the NKTZ reveal a close association with the geophysical evidence for rheological heterogeneities in the crust and mantle. In the northern NKTZ where two large inland earthquakes occurred recently, there appear to be many samples with He/He ratios significantly higher than those observed in the fore-arc side of northeast Japan. A plausible source of mantle helium could be attributed to upward mobilization of aqueous fluids generated by dehydration of the subducting Pacific Plate slab.
TiO(110) film electrode for lithium batteriesKim, K.-S.*; Tojigamori, Takeshi*; Suzuki, Kota*; Taminato, So*; Tamura, Kazuhisa; Mizuki, Junichiro; Hirayama, Masaaki*; Kanno, Ryoji*
Denki Kagaku Oyobi Kogyo Butsuri Kagaku, 80(10), p.800 - 803, 2012/10
Times Cited Count：13 Percentile：29.85(Electrochemistry)Electrochemical properties and structure changes of nano-sized LiTiO during lithium (de)intercalation wereinvestigated using a two-dimensional thin film electrode. LiTiO thin films were deposited on a Nb:SrTiO(110)substrate by a pulsed laser deposition technique. In situ X-ray diffraction measurements clarified the drastic structural changes of the LiTiOfilm upon soaking in the electrolyte and during the first intercalation and deintercalation processes. The surfaceregion of LiTiO had a different structure from the bulk during electrochemical cycling and could cause the nanosizedLiTiO electrodes to have high capacities and poor stabilities.
Yokoyama, Kenichi*; Murata, Yusuke*; Shiimori, Fusae*; Sakai, Junichi*; Yamamoto, Masahiro; Uchiyama, Gunzo; Nojima, Yasuo*; Fujine, Sachio*
Fushoku Boshoku Kyokai Dai-58-Kai Zairyo To Kankyo Toronkai Koenshu, p.11 - 12, 2011/09
Characteristics of hydrogen embrittlement of pure Ti and Ti-5Ta alloys were evaluated by stress loading and constant load tests. Mechanical properties of these materials were affected by hydride formation of surface layers. Although elongation was reduced by hydrogen absorption, embrittlement was observed only in the surface hydride area. It is also suggested that Ti-5Ta alloy was better susceptibility of hydrogen embrittlement than pure Ti.
Shiimori, Fusae*; Sakai, Junichi*; Yokoyama, Kenichi*; Motooka, Takafumi; Uchiyama, Gunzo; Nojima, Yasuo*; Fujine, Sachio*
Fushoku Boshoku Kyokai Dai-58-Kai Zairyo To Kankyo Toronkai Koenshu, p.13 - 14, 2011/09
In reprocessing plants, hydrogen gas was released by radiolysis of aqueous solution. The relationship of the amount of hydrogen gas and the amount of hydrogen absorption to titanium and Ti-5Ta were not clear. In this study, hydrogen was absorbed to titanium by the cathode charging and irradiation. Then, the amount of the hydrogen gas from solutions and the amount of the hydrogen absorbed to titanium was compared. It was found that a very small amount of the hydrogen by radiolysis was absorbed to titanium. It was suggested that the difference of the hydrogen absorption rate was caused by the difference of the hydrogen concentration on the metal surface.
Yada, Hiroki; Tsukimori, Kazuyuki; Maeda, Junichi*
JAEA-Research 2009-045, 64 Pages, 2010/03
JAEA-Research-2009-045.pdf:10.61MBJAEA-Research-2009-045(errata).pdf:11.48MB
In case the electromagnetic pump in the primary sodium purification system of Monju trips up, the sodium flow in the system stops. If we restart the system without stopping the main primary sodium circuit system, the mixing piping structure which connects the branch flow from the purification system to the main flow is subjected to thermal transient load because the cold stagnant sodium is pushed out and the hot sodium from main flow follows. The aim of this study is to assess the fatigue damage of the mixing piping structure in the primary sodium purification system of Monju in case its electromagnetic pump trips up and then it is restarted with keeping plant operation. From the analysis results, we concluded that (1) the fatigue damages were mainly dependent on the temperature difference between the cold sodium at the initial stage and the hot sodium after restart, (2) the fatigue damages were considerably mitigated by preheating and (3) even the severest case allows more than 400 cycles of this events.
Co
O; A New experimental technique using in situ X-ray diffraction and two-dimensional epitaxial film electrodesSakamoto, Kazuyuki*; Hirayama, Masaaki*; Sonoyama, Noriyuki*; Mori, Daisuke*; Yamada, Atsuo*; Tamura, Kazuhisa; Mizuki, Junichiro; Kanno, Ryoji*
Chemistry of Materials, 21(13), p.2632 - 2640, 2009/05
Times Cited Count：41 Percentile：73.88(Chemistry, Physical)Surface and bulk structural changes in LiNiCoO were observed during electrochemical reactions using synchrotron X-ray scattering and a restricted reaction plane of two-dimensional (2D) epitaxial-film electrodes. The bulk structural changes confirmed lithium diffusion through the (110) surface, which is perpendicular to the 2D edges of the layered structure. No (de)intercalation reaction was observed through the (003) surface in the voltage range of 3.0-5.0 V. However, intercalation proceeded below 3.0 V, which indicates unusual three-dimensional lithium diffusion in the 2D structure in the overlithiated state. Structural changes at the electrode surface were different from those in the bulk.
Mishima, Kenji*; Ino, Takashi*; Sakai, Kenji; Shinohara, Takenao; Hirota, Katsuya*; Ikeda, Kazuaki*; Sato, Hiromi*; Otake, Yoshie*; Omori, Hitoshi*; Muto, Suguru*; et al.
Nuclear Instruments and Methods in Physics Research A, 600, p.342 - 345, 2009/02
Times Cited Count：29 Percentile：84.89(Instruments & Instrumentation)A new beamline for a fundamental physics experiment is under construction at BL05 port in the Materials and Life Science Facility (MLF) at Japan Proton Accelerator Research Complex (J-PARC), this beamline is designed using novel techniques of neutron optics and it is termed "Neutron Optics and Physics". The beam from the moderator is deflected by multi-channel supermirrors and split into three branches for individual experiments. In this study, we have optimized the design of the beam optics and shields using the Monte Carlo simulation package PHITS. The neutron fluxes of beams are expected to be 
cm
str
sMW, 
cm
sMW, 
cmsMW, with polarization of 99.8%.
Yoshimoto, Masahiro; Ueno, Tomoaki; Togashi, Tomohito; Takeda, Osamu; Kanazawa, Kenichiro; Watanabe, Masao; Yamazaki, Yoshio; Kamiya, Junichiro; Takayanagi, Tomohiro; Kuramochi, Masaya; et al.
IEEE Transactions on Applied Superconductivity, 18(2), p.297 - 300, 2008/06
Times Cited Count：4 Percentile：30.85(Engineering, Electrical & Electronic)
X-ray reflectometry and LiNiCoO epitaxial film electrode synthesized by pulsed laser deposition methodHirayama, Masaaki*; Sakamoto, Kazuyuki*; Hiraide, Tetsuya*; Mori, Daisuke*; Yamada, Atsuo*; Kanno, Ryoji*; Sonoyama, Noriyuki*; Tamura, Kazuhisa; Mizuki, Junichiro
Electrochimica Acta, 53(2), p.871 - 881, 2007/12
Times Cited Count：44 Percentile：66.81(Electrochemistry)An experimental technique was developed for detecting structure changes at the electrode/electrolyte interface of lithium cell using synchrotron X-ray reflectometry and two-dimensional model electrodes with a restricted lattice plane. The electrode was constructed with an epitaxial film of LiNiCoO synthesized by the pulsed laser deposition method. These films provided an ideal reaction field suitable for detecting structure changes at the electrode/electrolyte interface during the electrochemical reaction. The X-ray reflectometry indicated a formation of a thin-film layer at the LiNiCoO (1 1 0)/electrolyte interface during the first charge-discharge cycle, while the LiNiCoO (0 0 3) surface showed an increase in the surface roughness without forming the surface thin-film layer.
Motojima, Osamu*; Yamada, Hiroshi*; Komori, Akio*; Oyabu, Nobuyoshi*; Muto, Takashi*; Kaneko, Osamu*; Kawahata, Kazuo*; Mito, Toshiyuki*; Ida, Katsumi*; Imagawa, Shinsaku*; et al.
Nuclear Fusion, 47(10), p.S668 - S676, 2007/10
Times Cited Count：34 Percentile：73.64(Physics, Fluids & Plasmas)The performance of net-current free heliotron plasmas has been developed by findings of innovative operational scenarios in conjunction with an upgrade of the heating power and the pumping/fuelling capability in the Large Helical Device (LHD). Consequently, the operational regime has been extended, in particular, with regard to high density, long pulse length and high beta. Diversified studies in LHD have elucidated the advantages of net-current free heliotron plasmas. In particular, an internal diffusion barrier (IDB) by a combination of efficient pumping of the local island divertor function and core fuelling by pellet injection has realized a super dense core as high as 5
10
m
, which stimulates an attractive super dense core reactor. Achievements of a volume averaged beta of 4.5% and a discharge duration of 54 min with a total input energy of 1.6 GJ (490 kW on average) are also highlighted. The progress of LHD experiments in these two years is overviewed by highlighting IDB, high-beta and long pulse.
