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Cd
廣瀬 雄介; 本多 史憲*; 土塔 寛*; 河村 直己*; Kvashnina, K. O.*; Amidani, L.*; Uhl
ov
, K.*; Koloren
, J.*; Havela, L.*
Physical Review B, 113(24), p.L241103_1 - L241103_6, 2026/06
被引用回数：1The regime of valence fluctuations, known from anomalous rare-earth systems with slow fluctuations between two different fn states, has not yet been identified by microscopic techniques at any Uranium compound. The reason may be in the predominant band character of U intermetallic compounds. Here we present U-L3 and M4 X-ray absorption spectra taken on UPdCd, which is a heavy-Fermion antiferromagnet. Although it has only one type of U site, the spectra obtained in the High Energy Resolution Fluorescence Detection mode display two edges, each associated with different valence states, 5f2 and 5f3. This is strongly suggestive of slow f2 - f3 fluctuations on the timescale longer than the characteristic time of the spectroscopy technique. Unlike 4f systems in which such fluctuations lead to a destruction of magnetism due to involvement of one non-magnetic state, the f2 and f3 states in U are both possibly magnetic, allowing for the magnetic ordering in the fluctuating state. Such a new situation can bring more light into emergent phenomena observable in U systems at the verge of 5f localization.
Kyriakou, I.*; Papadopoulos, A.*; Polopetrakis, I.*; Kotroumbelou, C.*; Plante, I.*; 松谷 悠佑; 甲斐 健師; Qiu, R.*; Li, J.*; Kundrt, P.*; et al.
Physics in Medicine & Biology, 71(8), p.085009_1 - 085009_25, 2026/04
被引用回数：0 パーセンタイル：0.00(Engineering, Biomedical)過去40年間にわたり、液体の水を対象としたモンテカルロ飛跡構造(MCTS)コードが世界中で数多く開発されてきたが、相互作用断面積は大きく異なる。本研究では、6種類の異なるMCTSコードの使用による、液相水中の低エネルギー電子輸送の物理的特性(電子阻止能、経路長、dose-point-kernel、微視的線量付与)の不確実性を評価することを目指した。コード間比較の結果により、特に100eV以下の低エネルギー領域において、MCTSコード間で大きな差異があることが明らかになり、電子線が重要な役割を果たすDNA損傷シミュレーションの精度に影響を与えることが示された。本研究は、液相水中の低エネルギー電子輸送計算に伴う不確実性を低減するために、MCTSコードで使用される物理モデルの更なる開発の必要性を浮き彫りにしている。
Guerinoni, E.*; 上田 祐生; 元川 竜平; Zemb, T.*; Pellet-Rostaing, S.*; Dourdain, S.*
Langmuir, 42(12), p.8313 - 8321, 2026/03
被引用回数：0 パーセンタイル：0.00(Chemistry, Multidisciplinary)Third phase formation in liquid-liquid extraction poses operational challenges by inducing organic phase separation, limiting extraction efficiency and process safety. Here, we employ combined ultra-small-angle X-ray (USAXS) and neutron scattering (USANS) to elucidate pre-transitional structures occurring during uranium extraction by tri-octylamine (TOA) in octane as diluent. SAXS highlights uranium-filled aggregates, while SANS captures all aggregates, regardless of uranium content. Extending the q-range from 0.004 to 3 
reveals two distinct populations: small spherical reverse micelle-like aggregates (radius 11 AA) and larger fluctuating domains exceeding 150 nm, consistent with Ornstein-Zernike critical fluctuations. Increasing TOA concentration amplifies these superstructures until divergence, the formation of a third phase. This study demonstrates that phase instability originates from the hierarchical condensation of water-filled aggregates around uranium-filled aggregates, rather than from simple micelle growth. Predicting such instability therefore requires accounting for the complete distribution of species, including water. The U-U distance in neighboring aggregate forming a supercluster is evidenced without ambiguity. Understanding such multiscale pre-transitional phenomena offers new routes to predict and mitigate phase separation in solvent extraction processes critical for nuclear fuel recycling.
Zn
Mo
O
Bao, S.*; Liao, J.*; Huang, Z.*; Shangguan, Y.*; Ma, Z.*; Zhang, B.*; Cheng, S.*; Xu, H.*; Song, Z.*; Dong, S.*; et al.
Physical Review Letters, 136(9), p.096502_1 - 096502_8, 2026/03
被引用回数：1 パーセンタイル：82.83(Physics, Multidisciplinary)Lattice vibrations can carry angular momentum and magnetic moments under broken inversion or time-reversal symmetry, forming so-called chiral phonons. While such excitations have been explored in nonmagnetic systems via optical probes, their direct detection in magnetic materials and coupling to spin excitations remain largely unexplored. Here, using neutron spectroscopy, sensitive to both nuclear and magnetic scattering, we reveal the magnetic signature of chiral phonons in ferrimagnetic FeZnMoO with Curie temperature 
K. Below 
, we observe enhanced magnetic scattering of phonons at small momenta, arising from strong magnon-phonon coupling. In addition, out-of-plane intensity modulation, phonon mode splitting, and field-induced Zeeman shifts are observed, all closely associated with the ferrimagnetic order. These features vanish above , where phonon spectra are dominated by nuclear scattering. These observations demonstrate the existence of chiral phonons carrying substantial magnetic moments that directly contribute to magnetic scattering, and establish neutron spectroscopy as a powerful, momentum-resolved probe of their magnetic character.
Wells, S. R.*; 岩田 圭弘; 宮部 昌文; 長谷川 秀一*
Applied Physics B, 132(3), p.32_1 - 32_8, 2026/02
被引用回数：0 パーセンタイル：0.00(Optics)全角運動量J:0-1-0のレーザー共鳴イオン化スキームを用いて、直線偏光レーザーによるカルシウム原子の偶奇同位体選択性を調べた。2本のレーザー偏光を互いに直交させることで、主要同位体
Caのイオン化を抑制し、奇数同位体
Caが選択的にイオン化されることを確認した。Ca奇数同位体の分離係数は最大
程度と得られた。
C filler; Surfactant-driven interfacial and microstructural controlNiu, X.*; Elakneswaran, Y.*; 菊池 亮佑*; Li, A.*; Seralathan, S.*; 平木 義久; 佐藤 淳也; 大杉 武史; 加美山 隆*; Walkley, B.*
Cement and Concrete Research, 200, p.108096_1 - 108096_17, 2026/02
被引用回数：1 パーセンタイル：27.19(Construction & Building Technology)The incorporation of boron (B) as a neutron absorber into metakaolin-based geopolymers for the remediation of radioactive debris following nuclear accidents has attracted considerable attention. In this study, boron carbide (BC) was employed as a functional filler, while cetyltrimethylammonium bromide (CTAB) acted as both a dispersant and a stabiliser to enhance the neutron shielding properties of metakaolin-based geopolymers. Although the addition of BC improved processability via a roller-ball effect and had no discernible impact on the geopolymerisation process, its weakly polar, negatively charged surface led to the formation of a loose, weak-shell interfacial transition zone (ITZ) between the filler and the matrix, thereby reducing mechanical strength and chemical stability. In contrast, CTAB self-assembled into an interdigitated monolayer on the BC surface, reversing its surface charge to positive and promoting its uniform dispersion within the matrix. This work offers a promising approach for engineering high-performance, multifunctional geopolymer composites for nuclear and environmental applications.
Yao, X.*; Chen, P.*; Verma, R.*; Zhao, X.*; Yang, H.-Y.*; DeBeer-Schmitt, L.*; Aczel, A. A.*; Wu, C.-M.*; Alba Venero, D.*; 大原 高志; et al.
Physical Review Letters, 136(8), p.086702_1 - 086702_6, 2026/02
被引用回数：1 パーセンタイル：82.83(Physics, Multidisciplinary)We demonstrate that a multi-k incommensurate magnetic state in the Weyl semimetal CeAlGe gives rise to a singular angular magnetoresistance (SAMR), which is an electrical transport signature capable of detecting magnetic field direction with exceptional precision. In contrast, its sister compound CeAlSi is devoid of both multi-k order and SAMR. We reveal that both phenomena appear upon 57% Ge substitution in CeAlSi1-xGex and coincide with electronic structure changes that soften the single-ion in-plane anisotropy and enhance Weyl-mediated magnetic interactions. These results unveil a remarkable connection between band topology, electronic transport, and collective magnetism in Weyl semimetals.
Villagrasa, C.*; Baiocco, G.*; Chaoui, Z.-E.-A.*; Dingfelder, M.*; Incerti, S.*; Kundrt, P.*; Kyriakou, I.*; 松谷 悠佑; 甲斐 健師; Parisi, A.*; et al.
PLOS ONE (Internet), 21(1), p.e0340500_1 - e0340500_22, 2026/01
被引用回数：3 パーセンタイル：98.80(Multidisciplinary Sciences)電離放射線被ばくの生物学的影響を理解するために重要なナノ線量測定は、分子スケールでの原子相互作用を再現するMonte Carlo Track Structure (MCTS)コードにより評価可能である。数十年にわたり独立して開発された様々なMCTSコードは、生物組織の主成分である液体水中の電子線の相互作用について、異なる物理モデルと断面積データセットを使用してきた。本研究では、様々なMCTSコード内の相互作用断面積の違いによって生じるナノ線量測定計算の不確実性を評価した。7つのMCTSコード(Geant4-DNA, PARTRAC, PHITS, MCwater、およびPTra)の計算結果から、平均電離数や2回以上の電離が起こる確率などの分子スケールの物理量に大きな相違があることが明らかとなった。最も大きな相違が確認されたのは低エネルギー電子で、相互作用断面積の寄与が不確実性の主要因であることがわかった。本成果より、断面積の相違が複雑なDNA損傷などの生物学的影響に無視できない影響を与えることが浮き彫りになった。
FeO
Lenander, E. Y.*; Nielsen, F. B.*; Lass, J.*; Hansen, U. B.*; Krighaar, K. M. L.*; Preuss, A.*; Weber, T.*; Enderle, M.*; Jacobsen, H.*; Stuhr, U.*; et al.
Physical Review B, 113(1), p.014424_1 - 014424_14, 2026/01
被引用回数：1 パーセンタイル：0.00(Materials Science, Multidisciplinary)The frustrated magnet BiFeO has been reported to exhibit complex spin dynamics coexisting with conventional spin wave excitations. The magnetic Fe
(
) ions are arranged into a distorted two-dimensional Cairo pentagonal lattice with weak couplings between the layers, developing long-ranged noncollinear antiferromagnetic order below 245 K. In order to enable studies and modeling of the complex dynamics close to 
, we have reexamined the magnetic excitations across the complete energy scale (
meV) at 10 K. We discover two distinct gaps, which can be explained by introducing, respectively, easy axis and easy plane anisotropy on the two unequivalent Fe sites. We develop a refined spin Hamiltonian that accurately accounts for the dispersion of essentially all spin-wave branches across the full spectral range, except around 40 meV, where a splitting and dispersion are observed. Polarization analysis shows that the system has magnetic anisotropic fluctuations, consistent with our model. A continuum of scattering is observed above the spin wave branches and is found to principally be explained by an instrumental resolution effect. The full experimental mapping of the excitation spectrum and the refined spin Hamiltonian provides a foundation for future quantitative studies of spin waves coexisting with unconventional magnetic fluctuations in this frustrated magnet found at higher temperatures.
Makarov, S. S.*; Zhakhovsky, V. V.*; Grigoryev, S. Yu.*; Chuprov, P.*; Pikuz, T. A.*; Inogamov, N. A.*; Khokhlov, V. A.*; Petrov, Y. V.*; Perov, E. A.*; Shepelev, V. V.*; et al.
Nature Communications (Internet), 16, p.11504_1 - 11504_13, 2025/12
被引用回数：0 パーセンタイル：0.00(Multidisciplinary Sciences)We demonstrate that a single 9-keV pulse from X-ray free-electron-laser can form a nanoscale mm-long cavity in LiF. The laser-generated shock pressure results in channel formation with >1,000 length-to-diameter aspect ratio. The development of void is analyzed via continuum and atomistic simulations revealing a sequence of processes leading to the final long cavity structure. This work presents the study of mm-long nanochannel formation by a single high-brilliance X-ray free-electron laser pulse.
Renaudi
e de Vaux, S.*; Li, S.*; Marrel, A.*; 江連 俊樹; 田中 正暁
Nuclear Engineering and Design, 444, p.114382_1 - 114381_15, 2025/12
被引用回数：0 パーセンタイル：0.00(Nuclear Science & Technology)本研究では、PLANDTL-2において実施した8ケースのナトリウム中自然循環過渡試験結果について報告する。試験パラメータは、一次系の初期条件、二次系停止時の熱慣性および崩壊熱除去システム(DHRS)の運転モードである。試験の結果、DHRSによる急速冷却時にプレナム内の温度成層化の発達に伴う一次系冷却材の逆流がみられることを明らかにするとともに、崩壊熱除去システムの起動から温度成層化の発達までの遅延時間を推定する新たな手法を提案した。さらに、今回明らかになった不安定性を回避するための今後の研究指針を提示した。
C-stainless steel composites using the improved MPS methodAhmed, Z.*; Wu, S.*; Sharma, A.*; Kumar, R.*; 山野 秀将; Pellegrini, M.*; 横山 諒*; 岡本 孝司*
International Journal of Heat and Mass Transfer, 250, p.127343_1 - 127343_17, 2025/11
被引用回数：5 パーセンタイル：82.90(Thermodynamics)The study aims to measure boron concentration through the unidirectional diffusion of boron within the stainless steel (SS) layers while evaluating the updated model ability to replicate melt relocation behavior and geometry. In the current MPS simulations, one scenario employed dummy walls as heat sources, while another scenario used SS surface particles as heat sources to avoid interference with the melt flow as it reached the bottom of the specimen.
志賀 基之; Elsner, J.*; Behler, J.*; Thomsen, B.
Journal of Chemical Physics, 163(13), p.134119_1 - 134119_13, 2025/10
被引用回数：3 パーセンタイル：61.88(Chemistry, Physical)水は高い熱容量などの特異な性質を持ち、生命や気候に重要な役割を果たしている。その熱容量の微視的起源を第一原理から理解するには、核の量子効果を考慮した高精度な経路積分分子動力学(PIMD)シミュレーションが必要であるが、計算コストが非常に高い。本研究では、密度汎関数理論(DFT)に基づいた高次元ニューラルネットワークポテンシャル(HDNNP)を用いることで、この課題を克服している。さらに、高効率なPIMDアルゴリズムを導入し、熱容量の収束データを得ることに成功した。特にrevPBE0-D3汎関数を用いた結果は実験と良く一致し、本手法が水の熱力学的性質の定量的理解に有効であることを示している。
-wave magnet with commensurate spin helix山田 林介*; Birch, M. T.*; Baral, P. R.*; 奥村 駿*; 中野 遼太*; Gao, S.*; 江澤 雅彦*; 野本 拓也*; Masell, J.*; 石原 由貴*; et al.
Nature, 646(8086), p.837 - 842, 2025/10
被引用回数：24 パーセンタイル：98.19(Multidisciplinary Sciences)Antiferromagnetic states with spin-split electronic structure give rise to novel spintronic, magnonic, and electronic phenomena despite (near-) zero net magnetization. The simplest odd-parity spin splitting, -wave, was originally proposed to emerge from a collective instability in interacting electron systems. Recent theory identifies a distinct route to realise -wave spin-split electronic bands without strong correlations, termed p-wave magnetism. Here we demonstrate an experimental realisation of a metallic -wave magnet.
三上 奈生; 相澤 康介; 植木 祥高*; Michel, F.*; Fache, J.*
Proceedings of 2025 International Congress on Advances in Nuclear Power Plants (ICAPP 2025) (Internet), 10 Pages, 2025/09
The present study evaluates the basic feasibility of an ensemble deep learning model to detect leakage from multi-channel acoustic signals in a steam generator (SG) of a sodium-cooled fast reactor (SFR). The acoustic signals from the bubbling and the gas blowout are measured by an array sensor in a basic experimental apparatus for SG to simulate noise and leak signals. Time-frequency representations (TFRs) are produced from these acoustic signals as the inputs of convolutional neural networks (CNNs). Three typical CNNs are introduced as candidates for the base model of ensemble deep learning. The proposed ensemble deep learning model reaches an accuracy of 95.43%, improved by 4.90% from the solo deep learning model. This result indicates that the proposed ensemble deep learning model has the potential to detect leakage more precisely in an actual SG of SFR.
Karimi, V.*; Qvistgaard, C. H.*; Schmidt, S.*; Wolfertz, A.*; Parker, J. D.*; 甲斐 哲也; 林田 洋寿*; 篠原 武尚; Angelis, S. D.*; Tengattini, A.*; et al.
ACS Applied Materials & Interfaces, 17(36), p.50742 - 50752, 2025/08
被引用回数：5 パーセンタイル：70.01(Nanoscience & Nanotechnology)Anodic Ti-based porous transport layers (PTLs) are paramount for advancing high-efficiency proton exchange membrane water electrolyzers (PEMWEs). One of the major challenges with the development of PEMWE is the PTL/catalyst layer interface passivation, which is commonly alleviated by coating precious metals such as Pt. Herein, we report, for the first time, the usage of polarized neutron imaging (PNI) on a half-half PTL approach to investigate current distribution inside the PTL layer under the influence of Ti passivation under PEMWE operando condition. First, the electrochemical study of PEMWE reveals an obvious advantage of Pt coating in preventing Ti passivation by showing 822 mV less overpotential at 1 A cm
(1.771 V) for the superior sample (Pt-coated PTL) compared to the PEMWE with pristine Ti PTL (2.539 V). Second, it is confirmed that using ex situ electronic and structural characterizations, Ti passivation cannot be recognized, suggesting a temporary passivation process in an operating PEMWE. Employing PNI for operando mapping of the current distribution inside the PEMWE shows that most of the electrical current favors the Pt-coated PTL, perfectly aligned with the results obtained from the high-resolution operando neutron radiography in which around 60% of the produced oxygen was found in the Pt-coated PTL.
Guerinoni, E.*; Zemb, T.*; 元川 竜平; 上田 祐生; 青柳 登; Pellet-Rostaing, S.*; Dourdain, S.*
Journal of Physical Chemistry B, 129(32), p.8210 - 8217, 2025/08
被引用回数：2 パーセンタイル：61.68(Biophysics)Liquid-liquid extraction of uranium involves an acidic aqueous phase in contact with an oil phase containing aliphatic amines and a linear alkane. Excess electrolyte in the oil phase leads to a third phase, hindering metal ion extraction and stripping. We determine the largest admissible extractant concentration (LOC) before macroscopic phase separation. Using small-angle X-ray scattering (SAXS) and small-angle neutron scattering (SANS), we analyze the microstructure of the phases. In all aliphatic diluents, the third phase consists of weak water-in-oil (w/o) aggregates with interdigitated hydrocarbon chains. Even after centrifugation, SANS detects residual deuterated solvent molecules. A fraction of these w/o aggregates contains uranium(VI) cations (U-loaded aggregates), which exhibit stronger attractive interactions than unloaded aggregates. This leads to the segregation of U-loaded aggregates into large clusters, detected as a Porod-type decay in SAXSbut absent in SANS at a low q-values.
- and 
-decay spectroscopy of 
AuMi
t, J.*; Andel, B.*; Andreyev, A. N.; 他61名*
Physical Review C, 112(2), p.024328_1 - 024328_16, 2025/08
被引用回数：0 パーセンタイル：0.00(Physics, Nuclear)An - and -decay study of laser-ionized and mass-separated Au (
=79, 
=103) was conducted at the ISOLDE Decay Station at CERN. 
- analysis significantly extended the level scheme of the daughter nucleus Pt, identifying 125 new levels and 336 new -ray transitions. The -decay scheme of Au was also extended, an -decay branching ratio of 0.129(11)% was measured and a spin-parity assignment for the 
Ir ground state was proposed.
Metzger, T. W. J.*; Fischer, P.*; 吉川 貴史; 齊藤 英治*; Kimel, A. V.*; Bossini, D.*
Physical Review Letters, 135(7), p.076702_1 - 076702_9, 2025/08
被引用回数：3 パーセンタイル：74.19(Physics, Multidisciplinary)Femtosecond laser excitation of nanometer thin heterostructures comprising a heavy metal and a magnetically ordered material is known to result in the emission of terahertz radiation. However, the nature of the emitted radiation from heavy metal/antiferromagnet heterostructures has sparked debates and controversies in the literature. Here, we unambiguously separate spin and charge contributions from Pt/NiO heterostructures by introducing an unprecedented methodology combining high external magnetic fields with a symmetry analysis of the emitted terahertz polarization. We observe two distinct mechanisms of terahertz emission, which we identify as optical difference frequency generation and ultrafast laser-induced quenching of the magnetization. We emphasize the absence of spin transport effects and signatures of coherent magnons. Overall, our Letter provides a general experimental methodology to separate spin and charge contributions to the laser-induced terahertz emission from heterostructures comprising a magnetically ordered material, thus holding great potential for advancing terahertz spintronics and establishing terahertz orbitronics.
C-stainless steel composite under severe reactor conditionsAhmed, Z.*; Kumar, R.*; 横山 諒*; 岡本 孝司*; Pellegrini, M.*; 山野 秀将
Proceedings of 21st International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-21) (Internet), 15 Pages, 2025/08
Scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) and X-ray photoelectron spectroscopy (XPS) confirmed the formation of metal carbides and the presence of boron in the eutectic melt. Characterizations results tell that not only boron, but carbon too diffuses in the eutectic melt which is a concern of recriticality. The current findings confirm the relocation of the BC-SS eutectic mixture with diffusion and precipitation of both boron and carbon, conditions likely to occur under extreme reactor conditions.
