Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
上羽 智之; 伊藤 昌弘*; 石谷 行生*
JAEA-Technology 2025-002, 25 Pages, 2025/06
JAEA-Technology-2025-002.pdf:2.06MB
ワイヤスペーサ型の高速炉燃料集合体では、バンドル-ダクト相互作用(Bundle-DuctInteraction; BDI)が厳しくなると、ワイヤを介して被覆管に加わる接触荷重によって被覆管断面の扁平化が生じるようになる。特に、バンドル最外周のピンは、ワイヤを介してダクトから被覆管に加わる荷重が大きくなって、この扁平化が顕著になることがある。この場合、扁平化はワイヤが被覆管にめり込んで被覆管が局所的に窪む状態となる。このような被覆管の局所変形をモデル化し、BDI解析コード"BAMBOO"のピンバンドル変形解析において被覆管の局所変形を考慮できるようにした。炉外バンドル圧縮試験では、バンドル最外周ピンとダクトの間にワイヤが存在するにもかかわらずピンとダクトの隙間がワイヤ径を下回ることが確認されているが、被覆管の局所変形モデルを組込んだBAMBOOコードによるバンドル圧縮試験の解析においても、バンドル最外周ピンの被覆管の局所変形によってバンドル圧縮試験結果と同様の傾向を再現できた。
Hartzell, S.*; Furutani, K. M.*; Parisi, A.*; 佐藤 達彦; 加瀬 優紀*; Deglow, C.*; Friedrich, T.*; Beltran, C. J.*
Radiation (Internet), 5(2), p.21_1 - 21_24, 2025/06
Microdosimetry is essential in particle therapy for understanding the biological effects of treatments by quantifying energy depositions within microscopic volumes. The calculation of the microdosimetric distributions can be carried out with physical models such as the Kiefer-Chatterjee (KC) track structure function and the Sato analytical microdosimetric function (AMF). Comprehensive comparisons across these physical models are lacking. The AMF is calculated for spherical domains, while the KC is traditionally calculated for a cylindrical domain. This study introduces a novel version of the KC function for spherical domains, allowing a direct comparison with AMF. The influence of each function on the calculation of the relative biological effectiveness (RBE) in carbon ion radiotherapy (CIRT) was evaluated.
rays in the 
La(
)
La reaction奥泉 舞桜*; Auton, C. J.*; 遠藤 駿典; 藤岡 宏之*; 広田 克也*; 猪野 隆*; 石崎 貢平*; 木村 敦; 北口 雅暁*; 古賀 淳*; et al.
Physical Review C, 111(3), p.034611_1 - 034611_6, 2025/03
被引用回数：0 パーセンタイル：0.00(Physics, Nuclear)The observed enhancement of Parity Violation in the vicinity of p-wave compound nuclear resonances for a variety of medium-heavy nuclei can be understood using the sp-mixing model. The sp-mixing model predicts several neutron energy-dependent angular correlations between the spin and momentum of neutron and -ray emitted from (n,) reactions. In this work, the correlation term 
in the La(
,)La
reaction was measured precisely and a significant transverse asymmetry was found in the transition to the excited states of La.
鈴木 誠也; 勝部 大樹*; 矢野 雅大; 津田 泰孝; 寺澤 知潮; 小澤 孝拓*; 福谷 克之; Kim, Y.*; 朝岡 秀人; 柚原 淳司*; et al.
Small Methods, 9(3), p.2400863_1 - 2400863_9, 2025/03
被引用回数：1 パーセンタイル：25.90(Chemistry, Physical)For group 14 monoelemental two-dimensional materials, such as silicene, germanene, and stanene, oxidation is a severe problem that alters or degrades their physical properties. This study shows that the oxidized germanene on Ag(111)/Ge(111) can be reformed to germanene by simple heating around 500 
C in a vacuum. The key reaction in reforming germanene is the desorption of GeO and GeO
during heating around 350 C. After removing surface oxygen, Ge further segregates to the surface, resulting in germanene. The reformed germanene has the same crystal structure, a (7
7) R19.1 supercell with respect to Ag(111), and has equivalent high quality to that of as-grown germanene on Ag(111)/Ge(111). Even after air oxidation, germanene can be reformed by annealing in a vacuum. On the other hand, the desorption of GeO and GeO at high temperatures was not suppressed even in the O backfilling atmosphere. This instability of oxidized germanene/Ag(111)/Ge(111) at high temperatures contributes to the ease of germanene reformation without oxygen. In other words, the present germanene reformation, as well as the segregation of germanene on Ag(111)/Ge(111), is a highly robust process as a synthesis method of germanene.
伊藤 健吾*; 高橋 真*; 加藤 千図*; 福谷 哲*; 松村 達郎; 藤井 俊行*
Journal of Radioanalytical and Nuclear Chemistry, 334, p.2467 - 2475, 2025/02
被引用回数：0 パーセンタイル：0.00(Chemistry, Analytical)本研究では、スズ、特に高レベル廃液に含まれるSn-126について、6種類の抽出剤による硝酸溶液からの溶媒抽出挙動について評価した。試験を行った抽出剤のうちHAAは高い効率を示したが、現状では工業的な応用に十分なデータは得られていない。塩酸を硝酸に加えた軽では、TBPとTEDTAにおいて、スズの分配比が1以上となった。しかしながら、工業的な応用に向けた実用的な課題と言う観点では、特に0.0008Mと言った低いスズ濃度におけるHAAによる抽出は、スズの回収についてより効果的である可能性がある。
能崎 幸雄*; 介川 裕章*; 渡邉 紳一*; 柚木 清司*; 洞口 泰輔*; 中山 颯人*; 山野井 一人*; Wen, Z.*; He, C.*; Song, J.*; et al.
Science and Technology of Advanced Materials, 26(1), p.2428153_1 - 2428153_39, 2025/02
被引用回数：0 パーセンタイル：0.00(Materials Science, Multidisciplinary)We present a novel method for generating spin currents using the gyromagnetic effect, a phenomenon discovered over a century ago. This effect, crucial for understanding the origins of magnetism, enables the coupling between various macroscopic rotational motions and electron spins. While higher rotational speeds intensify the effect, conventional mechanical rotations, typically, below 10,000 RPM, produce negligible results comparable to geomagnetic fluctuations, limiting applied research. Our studies demonstrate that spin current generation comparable to that of rare metals can be achieved through atomic rotations induced by GHz- range surface acoustic waves and the rotational motion of conduction electrons in metallic thin films with nanoscale gradient modulation of electrical conductivity. These effects, termed the acoustic gyromagnetic effect and the current-vorticity gyromagnetic effect, are significant in different contexts.
伊藤 健吾*; 守田 美咲*; 荒木 優太*; 加藤 千図*; 福谷 哲*; 松村 達郎; 藤井 俊行*
Solvent Extraction Research and Development, Japan, 32(1), p.53 - 62, 2025/00
高レベル廃液中のロジウム(Rh)とパラジウム(Pd)は主要な核分裂生成物である。本研究では、これらの白金族元素(PGEs)の新規な抽出剤HONTA及びADAAMによる溶媒抽出挙動を理解することを目的とした。これらの抽出剤はPdに親和性を示し、その分配係数は1を有意に超えPd分離に対する有効性を示している。これに対して、Rhの分配係数は、一貫して10
を下回っており、硝酸からの抽出効率が低いことを示している。しかし、硝酸カルシウム水和物を用いた塩析効果により、HONTAによるRhの分配係数約570を達成した。HONTAによる白金族元素の逆抽出の困難さを克服するため、HEDTA及びチオ尿素を用いた実験を行った。高濃度硝酸(
2M)におけるHEDTAによる逆抽出では約90%のPdが抽出されていたが、硝酸系におけるチオ尿素による逆抽出では、抽出されていたRhは約40%であり塩酸系では最大62.7%であった。
下村 浩一郎*; 幸田 章宏*; Pant, A. D.*; 砂川 光*; 藤森 寛*; 梅垣 いづみ*; 中村 惇平*; 藤原 理賀; 反保 元伸*; 河村 成肇*; et al.
Interactions (Internet), 245(1), p.31_1 - 31_6, 2024/12
J-PARC Muon Facility: MUSE (Muon Science Establishment) is responsible for the inter-university user program and the operation, maintenance, and construction of the muon beamlines, namely D-line, S-line, U-line, and H-line, along with the muon source at J-PARC Materials and Life Science Facility (MLF). In this paper, recent developments are briefly presented.
石川 諒尚; 田中 浩基*; 中村 哲志*; 熊田 博明*; 櫻井 良憲*; 渡辺 賢一*; 吉橋 幸子*; 棚上 裕生*; 瓜谷 章*; 鬼柳 善明*
Journal of Radiation Research (Internet), 65(6), p.765 - 775, 2024/11
被引用回数：0 パーセンタイル：0.00(Biology)From the viewpoints of the advantage depths (ADs), peak tumor dose, and skin dose, we evaluated the effect of neutron beam properties, namely, the ratio between thermal and epithermal neutron fluxes (thermal/epithermal ratio), fast neutron component, and -ray component on the dose distribution. Several parameter surveys were conducted with respect to the beam properties of neutron sources for boron neutron capture therapy assuming boronophenylalanine as the boron agent using our dose calculation tool, called SiDE. The ADs decreased by 3% at a thermal/epithermal ratio of 20% - 30% compared with the current recommendation of 
. The skin dose increased with the increasing thermal/epithermal ratio, reaching a restricted value of 14 Gy-eq at a thermal/epithermal ratio of 
. The fast neutron component was modified using two different models, namely, the "linear model," in which the fast neutron intensity decreases log-linearly with the increasing neutron energy, and the "moderator thickness (MT) model," in which the fast neutron component is varied by adjusting the moderator thickness in a virtual beam shaping assembly. Although a higher fast neutron component indicated a higher skin dose, the increment was 
at a fast neutron component of 
Gy cm
for both models. Furthermore, in the MT model, the epithermal neutron intensity was 
higher at a fast neutron component of 
Gy cm compared with the current recommendation of 
Gy cm. The -ray component also caused no significant disadvantages up to several times larger compared with the current recommendation.
Lim, G.-C.*; 福谷 克之; 他8名*
Journal of the American Chemical Society, 146(46), p.32013 - 32021, 2024/11
被引用回数：3 パーセンタイル：60.46(Chemistry, Multidisciplinary)We investigate ultrahigh concentration doping of hydrogen (H) into rutile-TiO(100) single crystals by low-energy (2.5 keV) hydrogen ion beam irradiation at low temperature (LT). While the hydrogen concentration was limited to H
TiO at 300 K, in situ nuclear reaction analysis (NRA) revealed ultrahigh concentration doping of hydrogen up to H
TiO by the LT irradiation at 50 K. The large (
8.2%) expansion of the out-of-plane lattice constant suggests that hydrogen occupies interstitial sites in rutile TiO. Hydrogens of early stage irradiation act as electron donors and induce a large increase in conductivity, which is consistent with theoretical studies in the dilute limit. The nature of excess H was investigated in situ by transport and photoemission measurements. After LT excess H doping and postannealing to room temperature, unusual electrical transport properties were observed while maintaining the ultrahigh H concentration. In situ photoemission measurements show that the excessively doped hydrogens by LT irradiation generate a deeper in-gap state (IGS) of metastable nature. Density functional theory predicts the formation of double neighboring interstitial hydrogens as a possible mechanism for the deeper IGS.
小澤 孝拓*; 福谷 克之; 他7名*
Nature Communications (Internet), 15, p.9558_1 - 9558_8, 2024/11
被引用回数：0 パーセンタイル：0.00(Multidisciplinary Sciences)Hydrogen, the smallest and lightest element, readily permeates a variety of materials and modulates their physical properties. Identification of the hydrogen lattice location and its amount in crystals is key to understanding and controlling the hydrogen-induced properties. Combining nuclear reaction analysis (NRA) with the ion channeling technique, we experimentally determined the locations of H and D in epitaxial nanofilms of titanium hydrides from the analysis of the two-dimensional angular mappings of NRA yields. Here we show that 11 at% of H are located at the octahedral site with the remaining H atoms in the tetrahedral site. Density functional theory calculations revealed that the structures with the partial octahedral site occupation are stabilized by the Fermi level shift and Jahn-Teller effect induced by hydrogen. In contrast, D was found to solely occupy the tetrahedral site owing to the mass effect on the zero-point vibrational energy. These findings suggest that site occupation of hydrogen can be controlled by changing the isotope mixture ratio, which leads to promising manifestation of novel hydrogen-related phenomena.
Kiliyankil, V. A.*; 福谷 克之; 他10名*
Journal of Materials Chemistry A, 12(42), p.28731 - 28743, 2024/10
被引用回数：0 パーセンタイル：0.00(Chemistry, Physical)The hydrogen evolution reaction (HER) on platinum (Pt) electrocatalysts involves the generation of hydrogen atoms and the formation of hydrogen molecules. It is commonly believed that the sites on the surfaces of the terrace (111, 110, and 100) domains are responsible for the formation of hydrogen molecules. However, the electrochemistry of the hydrogen atom generation is not well understood. We created edge-rich platinum electrocatalysts using nano-fabrics comprising entire single-walled carbon nanotubes (SWCNTs) as templates and supports. We then conducted the HER on the edge-rich Pt/SWCNT hybridized electrocatalysts and gained new insights into the electrochemical properties and functions of the edge sites. We propose that the edge sites are oxidized and serve two important functions: they act as atomic barriers, allowing electrons to accumulate within the terrace (111, 110, and 100) domains, and they transfer the electrons to the hydronium ions in the electrical double layer through discharge. Enhancing the discharge capability of the electrocatalysts is an efficient way to reduce the amount of platinum required, and this can be applied to various precious metal-based electrocatalysts to enhance their electrocatalytic activities and durability.
伊藤 健吾*; 川上 貴大*; 加藤 千図*; 福谷 哲*; 松村 達郎; 藤井 俊行*
Journal of Radioanalytical and Nuclear Chemistry, 333(10), p.5183 - 5189, 2024/10
被引用回数：1 パーセンタイル：46.79(Chemistry, Analytical)高レベル廃液からのウラン、プルトニウム、マイナーアクチノイド及び希土類元素の分離プロセスで使用される複数の抽出剤を用いて、硝酸溶液からのSe(VI)の溶媒抽出挙動を調べた。すべての抽出剤が分配比
1であったことから、プロセス中においてSeは残留水溶液中に残存することが明らかとなった。一方、希硝酸( 2M HNO
)、有機相としてオクタノール、濃硝酸(8M HNO)中において、抽出剤o-フェニレンジアミンではSeの分配比は1以上であった。濃硝酸(8M HNO)で逆抽出したところ、Seの新しい単一分離プロセスと回収の可能性が示唆された。
shetta lakes in the Soya Coast region and their paleoenvironmental significance with glacial isostatic adjustment in East Antarctica井上 源喜*; 本田 英介*; 伊東 敬祐*; Kang, I.*; 瀬戸 浩二*; 谷 幸則*; 渡邊 隆広; 鹿島 薫*; 大谷 修司*; 山中 寿朗*; et al.
Quaternary Science Reviews, 338, p.108822_1 - 108822_18, 2024/08
被引用回数：0 パーセンタイル：0.00(Geography, Physical)本研究では、南極宗谷海岸のルンドボークスヘッタ湖沼(丸湾南池,丸湾大池)の湖底堆積物の地質学的解析、有機成分分析、藻類等の顕微鏡観察及び放射性炭素年代測定を行い、完新世における本地域の環境変動と古陸水学的変遷を推測した。
中村 いずみ*; 滝藤 聖崇; 嶋津 龍弥*; 奥田 幸彦; 酒井 理哉*; 大谷 章仁*; 渡壁 智祥; 奥田 貴大; 渋谷 忠弘*; 白鳥 正樹*
Proceedings of ASME 2024 Pressure Vessels & Piping Conference (PVP 2024) (Internet), 9 Pages, 2024/07
A new seismic design procedure which evaluates the inelastic behavior of piping system by detailed finite element method (FEM) analysis has been developed in Japan (the JSME CC); however, the inelastic behavior is only considered for pipe body in the JSME CC, and the evaluation of inelastic behavior of pipe support structure is still not included. To clarify the current analytical accuracy of inelastic analysis of pipe support structures and to develop an analytical guideline to reasonably include the inelastic behavior of pipe support structure in the seismic design of piping system, a series of benchmark analysis on pipe support structures has been launched in 2022. The benchmark analysis of pipe support structures consists of mainly two stages; the first stage is the analysis of pipe support structures themselves, and the second stage is the analysis of piping system with inelastic support structure. As of January 2024, the first stage of benchmark analysis is in progress. It is confirmed that there are some variabilities in modeling of support structures, stress-strain relationship, and boundary conditions. The load-deflection relationships also show variability even when the support structures are in the elastic region. The effect of these variations to the response of piping system model is remained as future tasks.
molecule generation from dissociatively adsorbed water on TiO through photoexcitation加藤 弘一*; 長塚 直樹*; 福谷 克之
Journal of Physical Chemistry C, 128(20), p.8188 - 8198, 2024/05
被引用回数：2 パーセンタイル：45.97(Chemistry, Physical)The dissociative adsorption of water, migration of hydrogen, and molecular hydrogen generation on anatase and rutile TiO surfaces were studied by first-principles calculations. Whereas dissociated H and OH are adsorbed strongly on both TiO surfaces, the adsorption energies were substantially decreased when H and OH were combined with polarons, which can be generated through photoexcitation. The H atom coupled with a polaron was found to undergo codiffusion. While a large polaron smoothly follows the H atom migration in anatase, a small polaron in rutile stochastically moves and abruptly jumps between neighboring Ti sites during the H atom migration, exerting strong retardation to the H atom migration. The favorable path for two H atoms coupled with polarons to form an H molecule was examined. It was found that the energy barrier is low when an H atom migrates to the H-adsorbed O site to form a 2H-coordinated O atom, followed by H desorption on both anatase and rutile surfaces. The atom of the oxazole forms a more stable 
electronic configuration by the adsorption of two H atoms. The two H atoms on the same O atom, coupled with polarons, possibly tunnel through the energy barrier to a desorbing H molecule. It is also shown that an HO molecule possibly desorbs from the same 2H=O configuration.
寺阪 祐太; 佐藤 優樹; 瓜谷 章*
Nuclear Instruments and Methods in Physics Research A, 1062, p.169227_1 - 169227_6, 2024/05
被引用回数：1 パーセンタイル：48.38(Instruments & Instrumentation)We have developed a new position-sensitive optical fiber radiation sensor that achieves single-end readout and high dose rate application. The sensor determines the incident position of radiation on the optical fiber by using the wavelength dependency of light attenuation within the fiber. Through the analysis of the output wavelength spectrum from the fiber end, the incident position of radiation on the optical fiber can be inversely estimated using the spectrum unfolding procedure. Using this optical fiber sensor, we conducted a measurement of radiation distribution inside the Fukushima Daiichi Nuclear Power Station (FDNPS). The actual trend of incident position of radiation was successfully reproduced in a high dose rate area, with a maximum dose rate exceeding 100 mSv/h. This validates the effectiveness of our new position-sensitive optical fiber radiation sensor.
小澤 孝拓*; 福谷 克之; 他4名*
Journal of Vacuum Science and Technology A, 42(2), p.023402_1 - 023402_6, 2024/03
被引用回数：0 パーセンタイル：0.00(Materials Science, Coatings & Films)We synthesized an epitaxial film of high-entropy perovskite oxide (HEPO) consisting of three elements (Ca, Sr, Ba) in the A site and 12 elements (Si, Ti, Cr, Mn, Fe, Co, Ni, Ge, Zr, Sn, Ce, Hf) in the B site of ABO, and investigated hydrogen absorption properties in the HEPO film. The hydrogen depth profile was measured by nuclear reaction analysis via the 
H(
N, 
)
C reaction, showing the hydrogen absorption in the HEPO film with a maximum atomic concentration of 0.3 in the ABO unit. The diffusion coefficient of H in the film was analyzed from the H depth profile, and the activation barrier for diffusion was estimated to be (0.54
0.13) eV. An absorption band was observed at 3290 cm in the infrared absorption spectrum, which corresponds to the O-H stretching vibration. Simultaneous measurements of nuclear reaction and resistance revealed that the HEPO film remained electrically insulating regardless of the hydrogen concentration. We demonstrated that hydrogen is incorporated in HEPO forming OH species while keeping HEPO electrically insulating.
Zhou, X.*; 福谷 克之; 他9名*
Applied Physics Letters, 124(8), p.082103_1 - 082103_7, 2024/02
被引用回数：6 パーセンタイル：85.00(Physics, Applied)Electron-doping Mottronics within correlated vanadium dioxide opens up a paradigm to abruptly regulate the Mottronic phase transitions via adjusting the 
-orbital occupancy and configuration. Nevertheless, the potential impact of high-valence elementary substitution in the hydrogen-associated Mottronic transitions of VO is yet unclear. Herein, we demonstrate the role of high-valence elementary substitution in regulating the hydrogen-triggered Mottronic transitions of VO, assisted by quantitative hydrogen analysis using the nuclear reaction analysis. Substituting vanadium with a high-valence transitional metal within doped-VO largely reduces the hydrogen incorporation compared to the intrinsic VO under the low temperature hydrogenation process. Therefore, in contrast to hydrogen-induced electron localization of intrinsic VO upon low-temperature hydrogenation, only the hydrogen-triggered metallic state is observed within the hydrogen-associated phase diagram of W
V
O, as further probed by the near-edge X-ray absorption fine structure analysis and X-ray photoelectron spectroscopy. The present work reveals the overlooked role associated with the donor substitutions that largely influences the competitive equilibrium between the two rival hydrogen-induced Mottronic transitions within VO toward either the metallic or the highly insulating phase.
小澤 孝拓*; 福谷 克之; 他4名*
Journal of Physics and Chemistry of Solids, 185, p.111741_1 - 111741_7, 2024/02
被引用回数：3 パーセンタイル：30.38(Chemistry, Multidisciplinary)Hydrogen (H), the lightest element, exhibits quantum nature. Because the quantum tunneling is almost independent of temperature, H diffusion shows a transition from thermal hopping to quantum tunneling at low temperature. The role of the nuclear quantum effects on H diffusion, however, has not been clarified around the crossover region. Hence, we elucidate the hopping mechanism at intermediate temperature by a combination of accurate experimental data on H hopping rates and theoretical calculations for quantum states of H. We derived H hopping rates in Pd from the resistance evolution due to the H ordering associated with the 50 K anomaly. A gradual transition from thermal hopping to quantum tunneling was observed around 65 K. Three-dimensional quantum-mechanical analysis for the H quantum states revealed that the gradual transition is attributed to the resonant tunneling between the discrete vibrational states in the octahedral site and the tetrahedral site via the thermal vibrational excitation. Based on the results at different H concentrations and deuterium, we demonstrated that the tunneling rate is tuned by energy level matching and the resonance nature is manifested as the abruptness of the transition from thermal to quantum hopping.
