Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
江連 俊樹; 松下 健太郎; 佐々木 啓介; 田中 正暁
第29回動力・エネルギー技術シンポジウム講演論文集(インターネット), 5 Pages, 2025/06
ナトリウム冷却タンク型高速炉の実証炉(以下、実証炉)では、概念設計段階で取り組むべき研究課題の一つとして、炉心上部のホットプレナム部におけるガス巻込みの防止が挙げられている。これに関連して、われわれは、ガス巻込み評価手法(StreamViewer)の開発を進めている。本研究では、実証炉設計でのホットプレナム部ガス巻込み評価へのStreamViewer適用に向けて、評価手法の開発計画をまとめた。さらに、StreamViewerの妥当性確認を目的として実施予定の縮尺水流動試験の検討結果について報告する。
田中 圭*; 工藤 利博
マリンエンジニアリング, 60(2), p.21 - 26, 2025/04
令和6年5月31日に原子力船「むつ」の原子力動力推進システム及び同技術資料が「マリンエンジニアリングの航跡-未来へ続く先達の航跡-」に認定されたことを受け、日本マリンエンジニアリング学会より原子力船「むつ」に係る概要等に関する解説記事の投稿依頼を受け作成を行った。
田口 美岐*; 宮田 登*; 宮崎 司*; 青木 裕之; Ozawa, Satoru*; 長谷川 龍一 *; 盛満 裕真*; 川口 大輔*; 山本 悟*; 田中 敬二*
Polymer Journal, 7 Pages, 2025/03
被引用回数：0 パーセンタイル：0.00(Polymer Science)Polyrotaxane (PR) exhibits unique mechanical properties due to the ability of its cyclic molecules to move or slide along the axial chain. Thus, to design advanced polymer-based composite materials and organic devices, it is crucial to better understand the aggregation states at the surface and substrate interface in polymer films containing PR. Here, we report the depth profile of PR along the direction normal to the interface when it is mixed with polystyrene (PS). Neutron reflectivity and X-ray photoelectron spectroscopy revealed that PS and PR segregated at the surface and substrate interface, respectively, and that the extent of segregation depended on the length of PS. The surface enrichment of PS is driven by both energy and entropy, whereas the enrichment of PR at the substrate interface is energy driven.
Liu, Y.*; 宮田 登*; 宮崎 司*; 春藤 淳臣*; 川口 大輔*; 田中 敬二*; 青木 裕之
ACS Applied Materials & Interfaces, 8 Pages, 2025/00
The performance of structural adhesives is strongly influenced by the interfacial structure between the adhesive and adherend. In this study, we developed a nanometric stable interfacial layer derived from an epoxy resin system containing excess hardener. This layer, formed on solid substrates, exhibited excellent structural stability, even after extensive solvent washing. Neutron reflectometry (NR) was employed to investigate its structure under both dry and humid conditions, revealing a robust and well-defined interface that suppressed moisture accumulation at the adherend interface. FT-IR spectroscopy confirmed an excess of unreacted amino groups in the adsorbed layer, enabling further curing reactions with freshly applied epoxy resin. Re-coating experiments demonstrated that the adsorbed layer remained intact after thermal curing, suggesting strong interfacial compatibility. Notably, the presence of the adsorbed layer led to a significant enhancement in adhesive performance. Lap shear tests showed that the adhesion strength of the epoxy resin nearly doubled when the adsorbed layer was introduced at the interface. This approach does not rely on external coupling agents or primers, but instead utilizes a homologous material system to tailor interfacial properties through molecular-level design. The strategy presented here offers a practical and scalable method for improving adhesion in epoxy systems. By directly engineering the adhesive interface using components intrinsic to the epoxy formulation, this method enables reliable and enhanced bonding performance without altering the bulk material.
渡辺 賢一*; 須貝 優介*; 長谷川 創大*; 田中 清志朗*; 人見 啓太朗*; 野上 光博*; 篠原 武尚; Su, Y. H.; Parker, J. D.*; Kockelmann, W.*
Scientific Reports (Internet), 14, p.25224_1 - 25224_13, 2024/10
被引用回数：0 パーセンタイル：0.00(Multidisciplinary Sciences)Thallium bromide (TlBr) semiconductor detectors are being developed as promising candidates for high-detection-efficiency, high-energy-resolution, and room-temperature gamma-ray spectrometers. This study presents methods for evaluating TlBr crystal quality and carrier transport characteristics using neutron Bragg-dip imaging and the time-of-flight method for pulsed-laser-induced carriers, respectively. In this study, two samples obtained from both the upstream and downstream region in the crystal ingot were evaluated.
田中 琢朗*; 福岡 将史*; 戸田 賀奈子*; 中西 貴宏; 寺島 元基; 藤原 健壮; 庭野 佑真*; 加藤 弘亮*; 小林 奈通子*; 田野井 慶太朗*; et al.
ACS ES&T Water (Internet), 4(8), p.3579 - 3586, 2024/08
Radioactive cesium released by the Fukushima Daiichi Nuclear Power Plant accident in March 2011 remains in the forest environment and is being transported to the ocean via residential areas by runoff into river systems. Most of the 
Cs in river water exists as suspended forms, being strongly fixed by micaceous clay minerals. If this fraction can change its form into dissolved forms, this results in additional input of bioavailable Cs. In this study, in-situ sampling of Cs at multiple rivers in Fukushima Prefecture was conducted using the DGT (diffusive gradient in thin film) devices to investigate the dynamics of radioactive cesium in river environments. At almost all sampling points, the DGT Cs concentrations exceeded dissolved Cs concentrations, revealing the existence of a flux from the suspended to the dissolved forms. This additional input was found to have higher Cs/ 
Cs ratios, compared those of Cs in the dissolved form. This study demonstrates that the bioavailability of Cs can be underestimated by assessing only the dissolved form due to Cs flux from the suspended particles likely caused by their dissolution.
下北 啓輔*; 山本 勝宏*; 宮田 登*; 柴田 基樹*; 中西 洋平*; 荒川 勝利*; 竹中 幹人*; 木田 拓充*; 徳満 勝久*; 田中 亮*; et al.
Langmuir, 40(30), p.15758 - 15766, 2024/07
被引用回数：0 パーセンタイル：0.00(Chemistry, Multidisciplinary)To investigate the structure of the interface between polyethylene films and substrates, the neutron reflectivity (NR) of deuterated polyethylene (dPE) thin films deposited on Si substrates was measured, demonstrating water accumulation at the interface, even under ambient conditions. After leaching the thermally annealed dPE films in hot p-xylene, NR measurements were conducted on the layers remaining on the substrate, clearly revealing that the adsorption layer of dPE grew during annealing and consisted of two layers, an inner adsorption layer and an outer adsorption layer, as previously proposed for amorphous polymers. The inner adsorption layer was approximately 3.7 nm thick with a density comparable to that of the bulk. The outer adsorption layer was several nanometers thick and appeared to grow insufficiently on top of the inner adsorption layer under the annealing conditions examined in this study. This study clarifying the growth of the adsorption layer of polyethylene at the interface with an inorganic substrate is useful for improving the performance of polymer/inorganic filler nanocomposites due to the wide utility of crystalline polyolefins as polymer matrix materials in nanocomposites.
Kawano, Masayuki*; 盛満 裕真*; Liu, Y.*; 宮田 登*; 宮崎 司*; 青木 裕之; 川口 大輔*; 山本 悟*; 田中 敬二*
Macromolecules, 57(14), p.6625 - 6633, 2024/07
被引用回数：0 パーセンタイル：0.00(Polymer Science)A better understanding of the dynamic behavior of polymer chains on solid surfaces is indispensable for the design and construction of high-performance polymer composites. We herein visualized the in-plane movement of isolated poly(methyl methacrylate) (PMMA) and poly(tert-butyl methacrylate) (PtBMA) single chains on hydrophilic silicon wafers under ambient conditions by atomic force microscopy. Isolated PMMA chains adsorbed to the substrate, whereas PtBMA chains diffused, the degree of which was dependent on the humidity. Neutron reflectivity revealed the formation of a layer of condensed water on the substrate. All-atomistic molecular dynamics simulations implied that the diffusivity difference of the two polymers was based on the submerged depth in which a part of a chain existed. That is, the interaction of a polymer with the surface of the hydrophilic substrate primarily governs its lateral movement, or adsorption behavior, facilitated by the presence of water.
田中 万也; 山路 恵子*; 升屋 勇人*; 富田 純平; 小澤 麻由美*; 山崎 信哉*; 徳永 紘平; 福山 賢仁*; 小原 義之*; Maamoun, I.*; et al.
Chemosphere, 355, p.141837_1 - 141837_11, 2024/05
本研究では生物性マンガン酸化物を用いて人形峠坑水からのラジウム除去実験を行った。その結果、7.6mgの生物性マンガン酸化物を用いて3L坑水中から98%以上の
Raを除去することが出来た。これは固液分配係数に換算すると10
mL/gという非常に高い値となり、生物性マンガン酸化物が実際の坑水処理に有効であることを示している。
山口 瑛子; 栗原 雄一*; 永田 光知郎*; 田中 万也; 桧垣 正吾*; 小林 徹; 谷田 肇; 小原 義之*; 横山 啓一; 矢板 毅; et al.
Journal of Colloid and Interface Science, 661, p.317 - 332, 2024/05
被引用回数：6 パーセンタイル：72.77(Chemistry, Physical)ラジウム(Ra)は放射性元素であり、放射性廃棄物処理やウラン鉱山周辺の環境問題で重要なため、環境中Ra挙動の解明は急務である。しかし、Raは安定同位体が存在しないため分子レベルの実験が難しく、環境中で重要と考えられる粘土鉱物への吸着反応についても詳細なデータは得られていない。本研究では、広域X線吸収微細構造(EXAFS)法によりRaの分子レベルの情報を得る手法を確立し、さらに第一原理計算を利用することでRaの粘土鉱物への吸着構造を明らかにした。また、同族元素との比較を行い、粘土鉱物への吸着反応の系統的な理解に資する結果を得た。
Rapp, L.*; 松岡 健之*; Firestein, K. L.*; 寒河江 大輔*; 羽原 英明*; 向井 啓一郎*; 田中 和夫*; Gamaly, E. G.*; 兒玉 了祐*; 瀬戸 雄介*; et al.
Physical Review Research (Internet), 6(2), p.023101_1 - 023101_18, 2024/04
固体表面に超相対論的強度のレーザーパルスを照射すると表面にプラズマが発生し、内部は超高圧状態になることが知られている。本研究ではシリコン単結晶に当該レーザーを照射し、内部に生成された高圧相の結晶構造分析をBL22XU(JAEA-BL)の応力・イメージングステーションの回折システムにより実施した。その結果、内部には体心、菱面体、六方晶、正方晶というシリコンが持つといわれている高圧相の存在が確認された。今後は、さらにデータの蓄積を図り、材料内部の構造、強度、機能性制御への発展を図っていきたいと考えている。
O近藤 洋介*; Achouri, N. L.*; Al Falou, H.*; Atar, L.*; Aumann, T.*; 馬場 秀忠*; Boretzky, K.*; Caesar, C.*; Calvet, D.*; Chae, H.*; et al.
Nature, 620(7976), p.965 - 970, 2023/08
被引用回数：27 パーセンタイル：94.86(Multidisciplinary Sciences)非常に中性子が過剰な原子核Oは、陽子、中性子ともに魔法数であることから古くからその性質に興味が持たれていたが、酸素の最後の束縛核
Oよりも中性子が4個も多いため、これまで観測されてこなかった。この論文では、理化学研究所RIBFにて
Fからの1陽子ノックアウト反応によってOを生成し、そこから放出される中性子を測定することによって初めてその観測に成功した。核構造の観点からは、Oでは二重閉殻が保たれているか興味が持たれていたが、実験で得られた分光学的因子が殻模型計算で予言されて程度の大きいことから、閉殻構造をもたない可能性が高いことがわかった。
Ne at the transition into the island of inversion; Detailed structure study of NeWang, H.*; 安田 昌弘*; 近藤 洋介*; 中村 隆司*; Tostevin, J. A.*; 緒方 一介*; 大塚 孝治*; Poves, A.*; 清水 則孝*; 吉田 数貴; et al.
Physics Letters B, 843, p.138038_1 - 138038_9, 2023/08
被引用回数：4 パーセンタイル：69.46(Astronomy & Astrophysics)Neからの1中性子除去反応を用いて、Neの詳細な
線分光を行った。平行運動量分布の解析に基づき、Neの準位構造とスピンパリティを決定し、初めて負のパリティ状態を同定した。測定された断面積と運動量分布から、N=20とN=28のシェルギャップの消失の証拠となる有意なintruder p-wave強度が明らかになった。束縛状態については、弱いf-waveの可能性のある強度が観測された。いくつかの有効相互作用を用いた大規模殻模型計算では、実験的に観測された大きなp-wave強度と小さなf-wave強度は再現されず、Ne同位体に沿った反転の島への遷移の完全な理論的記述への挑戦が続いていることを示している。
Liu, Y.*; 宮田 登*; 宮崎 司*; 春藤 淳臣*; 川口 大輔*; 田中 敬二*; 青木 裕之
Langmuir, 39(29), p.10154 - 10162, 2023/06
被引用回数：11 パーセンタイル：74.82(Chemistry, Multidisciplinary)Water absorbed by epoxy resins from a humid atmosphere considerably influences their structure and properties. Examining the effects of absorbed water on epoxy resins at their interfaces with solid substrates is crucial because of their adhesive applications in various fields. The spatial distribution of absorbed water in epoxy resin thin films under high humidity was investigated in this study by neutron reflectometry. Water molecules were found to accumulate at the SiO
/epoxy resin interface after exposure at a relative humidity of 85% for 8 h. The formation of an ca.1 nm-thick condensed water layer was observed, and the thickness of this layer varied with curing conditions of epoxy systems. Furthermore, the water accumulation at the interface was noted to be affected by high-temperature and high-humidity environments. The formation of the condensed water layer is presumed to be related to the features of the polymer layer near the interface. The construction of the interface layer of epoxy resin would be affected by the interface constraint effect on the cross-linked polymer chain during the curing reaction. This study provides essential information for understanding the factors influencing the accumulation of water at the interface in epoxy resins. In the practical application, the process of improving the construction of epoxy resin near the interface would be a reasonable solution to resist the water accumulation in the interface.
野本 恭信; 水田 直紀; 守田 圭介; 青木 健; 沖田 将一朗; 石井 克典; 倉林 薫; 安田 貴則; 田中 真人; 井坂 和義; et al.
Proceedings of 30th International Conference on Nuclear Engineering (ICONE30) (Internet), 7 Pages, 2023/05
JAEA initiated an HTTR heat application test plan to develop for coupling technology between HTGR and hydrogen production facility. The principal objective of this test plan is to establish the high safety coupling technology for coupling a hydrogen production facility to HTGR through the demonstration of a hydrogen production by the proven technology of methane steam reforming method utilizing the HTTR as a high temperature heat source. The other objective is to develop for coupling equipment such as a high temperature isolation valve, a helium gas circulator and a high temperature insulation pipe. This paper describes the overview of an HTTR heat application test plan such as a draft test schedule and test targets for the demonstration of a hydrogen production. This paper also presents basic specifications of an HTTR heat application test facility such as the HTTR modification strategy, overall system configuration and heat and mass balance at rated test operation for the demonstration of a hydrogen production. Furthermore, the operation plan during the normal start-up and shut-down processes is proposed.
水田 直紀; 守田 圭介; 青木 健; 沖田 将一朗; 石井 克典; 倉林 薫; 安田 貴則; 田中 真人; 井坂 和義; 野口 弘喜; et al.
Proceedings of 30th International Conference on Nuclear Engineering (ICONE30) (Internet), 6 Pages, 2023/05
High temperature gas-cooled reactor (HTGR) is expected to extend the use of nuclear heat to a wider spectrum of industrial applications such as hydrogen production, high efficiency power generation, etc., due largely to high temperature heat supply capability as well as inherent safe characteristics. Japan Atomic Energy Agency (JAEA) have been contracted by the Agency for Natural Resources and Energy, part of the Ministry of Economy, Trade and Industry (METI) of Japan, to conduct its Hydrogen Production Demonstration Project Utilizing Very High Temperature. The primary objective of this project is to establish "coupling technology" between HTGR and hydrogen production facility in accordance with "Green Growth Strategy Through Achieving Carbon Neutrality in 2050". From this fiscal year, JAEA initiated a program to produce hydrogen using an HTTR (High Temperature Engineering Test Reactor) to develop coupling technologies between HTGR and hydrogen production facility required for a massive, cost-effective and carbon-free hydrogen production technology. This paper describes the development plan for coupling equipment which is required for an HTTR heat application test as coupling technologies between an HTTR and a hydrogen production facility. The coupling equipment is composed of a high temperature isolation valve to prevent the ingress of the flammable gas and/or the leakage of radioactive materials for nuclear facility, a secondary helium gas circulator to feed a high temperature helium gas, and a high temperature insulation pipe to transport of a high temperature helium gas from an Internal Heat Exchanger (IHX) to a hydrogen production facility. The development plan of coupling equipment contains each target and draft schedule.
Song, K.*; 伊藤 啓*; 伊藤 大介*; 大平 直也*; 齊藤 泰司*; 松下 健太郎; 江連 俊樹; 田中 正暁
Proceedings of 30th International Conference on Nuclear Engineering (ICONE30) (Internet), 10 Pages, 2023/05
自由表面渦によるガス巻込み現象はナトリウム冷却高速炉の炉出力を擾乱させる原因となり得る。そのため、ナトリウム冷却高速炉の実用的な安全設計のために、ガス巻込み現象によるガス巻込み流量を正確に評価する必要がある。本研究では、ガス巻込み現象の正確な評価のためのCFD解析の適用性について検討することを目的に、吸い込み管を有する円筒容器における自由表面渦およびそれに伴うガス巻込み現象のシミュレーションにCFD解析を適用し、CFD解析結果とガス巻込み現象の実験データとを比較した。その結果、CFD解析結果と実験結果とで吸い込み管内部の二相流形態がよく一致し、かつ自由液面における渦のガスコアの形状もよく一致した。よって、CFD解析によって、自由表面渦によって引き起こされるガス巻込み現象を許容誤差の範囲内で適切かつ正確に予測できることが確認された。
Fe
O
grown on AlO
; Effects of postdeposition annealing studied by XMCD野中 洋亮*; 若林 勇希*; 芝田 悟朗; 坂本 祥哉*; 池田 啓祐*; Chi, Z.*; Wan, Y.*; 鈴木 雅弘*; 田中 新*; 田中 雅明*; et al.
Physical Review Materials (Internet), 7(4), p.044413_1 - 044413_10, 2023/04
被引用回数：5 パーセンタイル：50.30(Materials Science, Multidisciplinary)We study the electronic and magnetic states of as-grown and annealed FeO(111)/AlO3(111) (
Co, Ni) thin films with various thicknesses grown on Si(111) substrates with the -AlO(111)buffer layers by using X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD), to investigate magnetically dead layers in these films. Although the magnetically dead layers in the as-grown samples are formed near the interface with the AlO buffer layer, we reveal that ferrimagnetic order is partially recovered by postdeposition annealing at 973 K for 48 hours in air. By analyzing the line shapes of the XAS and XMCD spectra, we conclude that, in the dead layers, there are a significant number of vacancies at the 
sites of the spinel structure, which may be the microscopic origin of the degraded ferrimagnetic order in the FeO thin films.
high energy resolution XAFS山本 直生*; 松村 大樹; 萩原 悠人*; 田中 啓偉*; 長谷川 優太*; 石井 賢司*; 田中 裕久*
Journal of Power Sources, 557, p.232508_1 - 232508_10, 2023/02
被引用回数：8 パーセンタイル：50.96(Chemistry, Physical)Oxygen Reduction Reaction (ORR) is one of the key electrochemical reactions, especially in Polymer Electrolyte Fuel Cells (PEFCs). In this work, the reaction pathway and intermediate species such as molecular-type oxygen during ORR were discussed. High energy resolution X-ray absorption fine structure spectra at the Pt L
-edge were obtained to observe the electronic structure of Pt catalyst. Carbon-supported Pt nanoparticles as powder catalysts were used for measurement as more realistic conditions, and the species adsorbed on the Pt nanoparticles were analyzed while controlling under the potentials in acidic electrolyte solution with N or O gas bubbling. Molecular-type oxygen adsorption species is observed only in the O-bubbled electrolyte solution. This intermediate adsorption species is assigned to a hydrogen superoxide.
TaSのX線磁気円二色性による研究; FeTiSとの比較芝田 悟朗; Won, C.*; Kim, J.*; 野中 洋亮*; 池田 啓祐*; Wan, Y.*; 鈴木 雅弘*; 小出 常晴*; 田中 新*; Cheong, S.-W.*; et al.
Photon Factory Activity Report 2022 (インターネット), 2 Pages, 2023/00
Feをインターカレートした遷移金属ダイカルコゲナイド化合物FeTiSおよびFeTaSは、巨大な保磁力および垂直磁気異方性を示す強磁性体になることが知られている。我々は以前、FeTiSについてのX線磁気円二色性(XMCD)実験の結果から、Fe
の凍結していない軌道磁気モーメントが結晶場の1次摂動によって直接磁気異方性エネルギーを生むことを明らかにした。今回、FeTiSよりもさらに強い磁気異方性を示す遷移金属ダイカルコゲナイドFeTaSについて同様にXMCD実験を行い、磁気異方性の強さが何によって左右されているかを探ることを試みた。
