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Villagrasa, C.*; Baiocco, G.*; Chaoui, Z.-E.-A.*; Dingfelder, M.*; Incerti, S.*; Kundr
t, 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
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。
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
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：2 パーセンタイル：92.08(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
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。
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：0 パーセンタイル：0.00Anodic 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：0 パーセンタイル：0.00Liquid-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
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.
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.
Chauvin, N.*; Martin, P.*; 尾形 孝成*; Calabrese, R.*; Janney, D.*; 廣岡 瞬; 加藤 正人; Staicu, D.*; McClellan, K.*; White, J.*; et al.
NEA/NSC/R(2024)1 (Internet), 289 Pages, 2025/07
OECD/NEAのWorking Party on Scientific Issues of Advanced Fuel Cycles(WPFD)/Expert Group on Innovative Fuel Elementsでは、各国の核燃料研究の専門家による協力のもとで、酸化物及び金属燃料を対象とした推奨燃料物性値を取りまとめ、燃料照射挙動解析コードのベンチマークに反映する活動を行ってきた。本報告は、公開文献をベースに推奨燃料物性値を取りまとめたものであり、格子定数、融点、熱膨張、熱伝導率、比熱、弾性率、酸素ポテンシャル及び相変化について、物性値、評価式及びそれらの適用範囲を示す。
青山 高士; Choudhary, S.*; Pandaleon, A.*; Burns, J. T.*; Kokaly, M.*; Restis, J.*; Ross, J.*; Kelly, R. G.*
Corrosion, 81(6), p.609 - 621, 2025/06
被引用回数：1 パーセンタイル：58.04(Materials Science, Multidisciplinary)This study presents a new test method for inducing controlled corrosion damage within simulated fastener holes of aluminum alloys, aimed at pretreating fatigue test specimens. The method involves insulating the outer surface while exposing the fastener hole surface to electrolytes containing 0.66 M NaCl + 0.1 M AlCl 
with varying concentrations of K 
S O 
. The evolution of corrosion damage within the fastener hole was examined as a function of exposure duration, electrolyte composition, and volume, as well as the effect of galvanic coupling with a SS316 cathode. Results indicate that fissure depth increases with an increase in K S O concentration but does not progress further after 24-48 hours of exposure in the chemical, or freely-corroding, exposure test. In contrast, galvanic coupling with a SS316 plate significantly accelerates corrosion, leading to much deeper fissures in a shorter time. The importance of electrolyte replenishment has been explored using electrochemical measurements, revealing the impact of evolving electrolyte chemistry. Beyond its application in fatigue specimen pretreatment, this method provides a simple yet effective approach for studying localized corrosion and evaluating mitigation strategies for fastener holes in aerospace structures.
InPatel, D.*; Srivastava, P. C.*; 清水 則孝*; 宇都野 穣
Physical Review C, 111(6), p.064303_1 - 064303_13, 2025/06
被引用回数：0 パーセンタイル：0.00In同位体は陽子数50の魔法数から1つだけ少ない陽子数をもつため、陽子の一粒子エネルギーを強く反映しているとされている。これらの同位体に対し、大規模殻模型計算を行った結果、これまでは重要でないと考えられていた
軌道や
軌道の配位混合が第一励起準位を正しく得るのに大きな役割を果たすことがわかった。最近測定された磁気モーメント、四重極モーメントや、分光学的因子もよく再現されるとともに、この描像がよく成り立つことがわかった。
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.
neutron imaging and diffraction analysis revealing spatial lithiation phase evolution in an ultra-thick graphite electrodeStrobl, M.*; Baur, M. E.*; Samothrakitis, S.*; Molamud, F.*; Zhang, X.*; Tung, P. K. M.*; Schmidt, S.*; Woracek, R.*; Lee, J.*; 鬼柳 亮嗣; et al.
Advanced Energy Materials, 15(20), p.2405238_1 - 2405238_9, 2025/05
被引用回数：2 パーセンタイル：86.29(Chemistry, Physical)Energy-efficient, safe, and reliable Li-ion batteries (LIBs) are required for a wide range of applications. The introduction of ultra-thick graphite anodes, desired for high energy densities, meets limitations in internal electrode transport properties, leading to detrimental consequences. Yet, there is a lack of experimental tools capable of providing a complete view of local processes. Here, a multi-modal measurement approach is introduced, enabling quantitative spatio-temporal observations of Li concentrations and intercalation phases in ultra-thick graphite electrodes. Neutron imaging and diffraction concurrently provide correlated multiscale information from the scale of the cell down to the crystallographic scale. In particular, the evolving formation of the solid electrolyte interphase (SEI), observation of gradients in total lithium content, as well as in the formation of ordered Li
C
phases and trapped lithium are mapped throughout the first charge-discharge cycle of the cell. Different lithiation stages co-exist during charging and discharging; delayed lithiation and delithiation processes are observed in central regions of the electrode, while the SEI formation, potential plating, and dead lithium are predominantly found closer to the interface with the separator. The study emphasizes the potential to investigate Li-ion diffusion and the kinetics of lithiation phase formation in thick electrodes.
under pressureKnafo, W.*; Thebault, T.*; Raymond, S.*; Manuel, P.*; Khalyavin, D. D.*; Orlandi, F.*; Ressouche, E.*; Beauvois, K.*; Lapertot, G.*; 金子 耕士; et al.
Physical Review X, 15(2), p.021075_1 - 021075_16, 2025/05
被引用回数：0 パーセンタイル：94.37(Physics, Multidisciplinary)The discovery of multiple superconducting phases in UTe boosted research on correlated-electron physics. This heavy-fermion paramagnet was rapidly identified as a reference compound to study the interplay between magnetism and unconventional superconductivity with multiple degrees of freedom. The proximity to a ferromagnetic quantum phase transition was initially proposed as a driving force to triplet-pairing superconductivity. However, we find here that long-range incommensurate antiferromagnetic order is established under pressure. The propagation vector k
= (0.07, 0.33, 1) of the antiferromagnetic phase is close to a wavevector where antiferromagnetic fluctuations have previously been observed at ambient pressure. These elements support that UTe is a nearly-antiferromagnet at ambient pressure. Our work appeals for theories modelling the evolution of the magnetic interactions and electronic properties, driving a correlated paramagnetic regime at ambient pressure to a long-range antiferromagnetic order under pressure. A deeper understanding of itinerant-f-electrons magnetism in UTe will be a key for describing its unconventional superconducting phases.
Hartzell, S.*; Parisi, A.*; 佐藤 達彦; Beltran, C. J.*; Furutani, K. M.*
Physics in Medicine & Biology, 70(10), p.105010_1 - 105010_19, 2025/05
被引用回数：0 パーセンタイル：68.59(Engineering, Biomedical)In this study, we presented the implementation of the Analytical Microdosimetric Function (AMF) within the TOPAS Monte Carlo platform as an efficient and accurate surrogate for track structure simulations. The AMF extension demonstrated strong agreement with TOPAS nBio track structure simulations for ions relevant to particle therapy and space applications, while offering significant computational advantages.
西 剛史*; 松本 早織*; 山野 秀将; 林 喜一郎*; 遠藤 理恵*; Bell
, M. R.*; Neubert, L.*; Volkova, O.*
Steel Research International, 96(5), p.2300766_1 - 2300766_6, 2025/05
被引用回数：5 パーセンタイル：79.07(Metallurgy & Metallurgical Engineering)ニッケル基超合金について、密度は最大気泡圧法、粘度はるつぼ振動法、表面張力は最大気泡圧法により、測定データを得た。
Neubert, L.*; Bell, M. R.*; 山本 泰生*; 西 剛史*; 山野 秀将; Ahrenhold, F.*; Volkova, O.*
Steel Research International, 96(5), p.2400237_1 - 2400237_8, 2025/05
被引用回数：2 パーセンタイル：32.08(Metallurgy & Metallurgical Engineering)Density, surface tension, and viscosity of various liquid electrical steels are measured at different temperatures, varying in their silicon content between 3 and 6mass%.
Niu, X.*; Elakneswaran, Y.*; Li, A.*; Seralathan, S.*; 菊池 亮佑*; 平木 義久; 佐藤 淳也; 大杉 武史; Walkley, B.*
Cement and Concrete Research, 190, p.107814_1 - 107814_17, 2025/04
被引用回数：2 パーセンタイル：88.59(Construction & Building Technology)Metakaolin-based geopolymers have attracted significant interest in decontaminating radioactive debris from the Fukushima nuclear accident. This study explored the incorporation of boron (B) into geopolymers using boric acid as the source, with the goal of developing B-enriched geopolymers for enhanced radionuclide immobilisation and neutron capture potential.
Md produced in the 
He + 
Es reaction西尾 勝久; 廣瀬 健太郎; 牧井 宏之; Orlandi, R.; Kean, K. R.*; 塚田 和明; 豊嶋 厚史*; 浅井 雅人; 佐藤 哲也; Chiera, N. M.*; et al.
Physical Review C, 111(4), p.044609_1 - 044609_12, 2025/04
被引用回数：0 パーセンタイル：70.48(Physics, Nuclear)In spontaneous fission (SF) it is found that the mass-asymmetric fission of well-known actinides suddenly changes to the symmetric fission when nucleus has a mass number 
larger than 257. We have measured for the first time fission-fragment mass and total-kinetic-energy (TKE) distributions of the excited compound nucleus Md, populated in the reaction He+Es, using the rare isotope Es with a short half-life, 
=276 days. The fission of Md can be interpreted as involving 3 fission modes: an mass-asymmetric mode and two modes of mass-asymmetric fissions, the latter two are manifested by different TKE values. Predominantly symmetric fission was obtained at the excitation energy of 15.0 MeV. By increasing the energy to 18.0 MeV, the asymmetric fission mode dominates. Both such a strong change of fission modes within a small increase of excitation energy and the enhancement of asymmetric split are new phenomena in fission.
