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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
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.
岩本 修; 岩本 信之; 国枝 賢; 湊 太志; 中山 梓介; 安部 豊*; 椿原 康介*; 奥村 森*; 石塚 知香子*; 吉田 正*; et al.
Journal of Nuclear Science and Technology, 60(1), p.1 - 60, 2023/01
The fifth version of Japanese Evaluated Nuclear Data Library, JENDL-5, was developed. JENDL-5 aimed to meet a variety of needs not only from nuclear reactors but also from other applications such as accelerators. Most of the JENDL special purpose files published so far were integrated into JENDL-5 with revisions. JENDL-5 consists of 11 sublibraries: (1) Neutron, (2) Thermal scattering law, (3) Fission product yield, (4) Decay data, (5) Proton, (6) Deuteron, (7) Alpha-particle, (8) Photonuclear, (9) Photo-atomic, (10) Electro-atomic, and (11) Atomic relaxation. The neutron reaction data for a large number of nuclei in JENDL-4.0 were updated ranging from light to heavy ones, including major and minor actinides which affect nuclear reactor calculations. In addition, the number of nuclei of neutron reaction data stored in JENDL-5 was largely increased; the neutron data covered not only all of naturally existing nuclei but also their neighbor ones with half-lives longer than 1 day. JENDL-5 included the originally evaluated data of thermal scattering law and fission product yield for the first time. Light charged-particle and photon induced reaction data were also included for the first time as the JENDL general purpose file.
rays in the 
Sn(
)
Sn reaction遠藤 駿典; 奥平 琢也*; 安部 亮太*; 藤岡 宏之*; 広田 克也*; 木村 敦; 北口 雅暁*; 奥 隆之; 酒井 健二; 嶋 達志*; et al.
Physical Review C, 106(6), p.064601_1 - 064601_7, 2022/12
被引用回数：0 パーセンタイル：0.02(Physics, Nuclear)熱外中性子入射により形成される複合核において観測された、空間反転対称性の破れの大きな増幅は、今のところ複合核状態の入射チャネルにおけるパリティの異なる部分波の混合の結果として説明されている。さらに時間反転対称性の破れも同様のメカニズムで増幅されることが示唆されている。この入射チャネルにおける混合は、複合核共鳴から放出される個々のガンマ線のエネルギー依存なスピン-角相関を引き起こす。本研究ではJ-PARC・MLF・ANNRIにて偏極熱外中性子ビームを用い、Sn()Sn反応におけるガンマ線強度分布が、中性子の偏極方向に依存することを確認した。
atomic X-ray spectroscopy using a counter-emulsion hybrid method藤田 真奈美; 長谷川 勝一; 細見 健二; 市川 真也; 市川 裕大; Kim, S.; 七村 拓野; 佐甲 博之; 田村 裕和; 山本 剛史; et al.
Progress of Theoretical and Experimental Physics (Internet), 2022(12), p.123D01_1 - 123D01_17, 2022/12
被引用回数：0 パーセンタイル：0.01(Physics, Multidisciplinary) atomic X-ray spectroscopy is one of the most useful methods for investigation of the 
-nucleus strong interaction. Since the X-ray energy is shifted and/or broadened due to the -nucleus strong interaction compared to those calculated from electromagnetic interaction alone, the measurement of the energy shift, 
E, and the width, 
, give us information on the -nucleus potential. A serious problem in the measurement is the significant background derived from in-flight decay. A novel method of identifying stopped events using the nuclear emulsion was developed to realize the first atomic X-ray spectroscopy experiment as the J-PARC E07 experiment, which also aimed at searching for 
and hypernuclei in the emulsion. The X-rays emitted from Br and Ag atoms were measured using germanium detectors. No clear peaks were observed in the obtained spectra. However, we succeeded in reducing the background to 1/170 by this method employing coincidence measurements using nuclear emulsion and X-ray detectors.
atoms (J-PARC E03, E07 and future)山本 剛史; 藤田 真奈美; 後神 利志*; 原田 健志*; 早川 修平*; 細見 健二; 市川 裕大; 石川 勇二*; 鎌田 健人*; 叶内 萌香*; et al.
EPJ Web of Conferences, 271, p.03001_1 - 03001_5, 2022/11
X-ray spectroscopy of hadronic atoms give us various information on the strong interaction between hadrons and nuclei. At J-PARC, we are aiming for the world-first detection of the X rays from atoms with a doubly strange hyperon, . Recently, two experiments, J-PARC E07 and J-PARC E03, have been performed for the detection of X rays from atoms. Overview and status of these measurements will be presented. We will also discuss future plan of X-ray spectroscopy on -atoms, which can be performed together with high resolution hyper nuclear spectroscopy using newly constructed S-2S spectrometer. Preparation status will be shown in this contribution.
atomic X-rays藤田 真奈美; 細見 健二; 石川 勇二*; 叶内 萌香*; 小池 武志*; 小椋 裕*; 田村 裕和; 谷田 聖; 鵜養 美冬*; 山本 剛史
Nuclear Instruments and Methods in Physics Research A, 1042, p.167439_1 - 167439_9, 2022/11
被引用回数：1 パーセンタイル：71.47(Instruments & Instrumentation) atomic X-ray spectroscopy is a powerful method of studying the N interaction, for which very limited experimental data are currently available. For this reason, we constructed a germanium (Ge) detector array referred to as Hyperball-X and conducted the first-ever atomic X-ray measurements in 2016 and 2017 at J-PARC. We developed a novel method for in-beam energy calibration of Ge detectors. Three rays (202 keV, 307 keV, and 511 keV) from 
Lu in LSO scintillation counters and 
Na source were used as reference. The 
and 
coincidence detection using the Ge detectors and LSO counters allows for continuous in-beam calibration with this new calibration method, and the calibration uncertainty is reduced to less than 
100 eV for energies ranging from 202 to 511 keV.
山本 誠士郎*; 大平 直也*; 伊藤 大介*; 伊藤 啓*; 齊藤 泰司*; 今泉 悠也; 松場 賢一; 神山 健司
Proceedings of 12th Japan-Korea Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS12) (Internet), 4 Pages, 2022/10
To develop a microscopic pressure drop prediction model based on detailed measurement data of gas liquid two-phase flow, the pressure drop was measured in the vertical upward gas-liquid two-phase flow formed in quasi-2D test section. The measurement results showed that the pressure drop in the quasi-2D test section was much smaller than that in the ordinal packed bed system, which suggests that the pressure drop mechanism in the quasi-2D test section could be different from that in the ordinal packed bed system due to differences in two-phase flow characteristics in the two systems. The void fraction distribution was also measured in the quasi-2D test section by the X-ray imaging technique, which revealed that there was a local distribution of the void fraction in the channel unit structure of the closest packed bed.
rays from the 
-wave resonance of Sn古賀 淳*; 高田 秀佐*; 遠藤 駿典; 藤岡 宏之*; 広田 克也*; 石崎 貢平*; 木村 敦; 北口 雅暁*; 新實 裕大*; 奥平 琢也*; et al.
Physical Review C, 105(5), p.054615_1 - 054615_5, 2022/05
被引用回数：1 パーセンタイル：67.14(Physics, Nuclear)J-PACR MLFのパルス中性子源及びBL04 ANNRIに設置されたゲルマニウム検出器を用いて、Sn(n,)反応により生じるガンマ線の中性子エネルギー依存する角度分布を測定した。Snの複合核状態からSnの基底状態への遷移で発生する9327keVのガンマ線に関して、角度によって1.33eVの波共鳴の形状が変わることが明らかに確認できた。この共鳴の低エネルギー側の積分値と高エネルギー側の積分値をそれぞれ
で表したとき、非対称性
は
cos
という角度依存をし、それぞれのパラメータ値が
、
であることがわかった。
吉田 寿雄*; 山本 旭*; 細川 三郎*; 山添 誠司*; 吉川 聡一*; 原 賢二*; 中村 充孝; 蒲沢 和也*; 田中 庸裕*
Topics in Catalysis, 64(9-12), p.660 - 671, 2021/08
被引用回数：2 パーセンタイル：11.96(Chemistry, Applied)Inelastic neutron scattering (INS) enables direct and selective observation of H species due to the extremely large incoherent neutron scattering cross section of a hydrogen atom. In the present study, the adsorbed H species on some heterogeneous precious metal catalysts supported by alumina and carbon black were investigated by in situ INS spectroscopy with a newly designed sample cell. Three alumina-supported metal catalysts having Pt, Pd, and Rh metal nanoparticles with different particle sizes exhibited different INS spectra in intensities and band distribution. Observation of the H species on the metal nanoparticles and the alumina surface revealed their properties. In addition, the H atoms stored in Pd nanoparticles were observed as palladium hydride. In contrast, the H species on a Pt catalyst supported by carbon black were found to be strongly adsorbed on the carbon support.
rays in the 
La(
)
La
reaction奥平 琢也*; 遠藤 駿典; 藤岡 宏之*; 広田 克也*; 石崎 貢平*; 木村 敦; 北口 雅暁*; 古賀 淳*; 新實 裕大*; 酒井 健二; et al.
Physical Review C, 104(1), p.014601_1 - 014601_6, 2021/07
被引用回数：2 パーセンタイル：53.07(Physics, Nuclear)Neutron energy-dependent angular distributions were observed for individual rays from the 0.74 eV -wave resonance of La+
to several lower excited states of La. The -ray signals were analyzed in a two dimensional histogram of the -ray energy, measured with distributed germanium detectors, and neutron energy, determined with the time-of-flight of pulsed neutrons, to identify the neutron energy dependence of the angular distribution for each individual rays. The angular distribution was also found for a photopeak accompanied with a faint -wave resonance component in the neutron energy spectrum. Our results can be interpreted as interference between 
- and -wave amplitudes which may be used to study discrete symmetries of fundamental interactions.
酒井 健二; 奥 隆之; 奥平 琢也; 甲斐 哲也; 原田 正英; 廣井 孝介; 林田 洋寿*; 加倉井 和久*; 清水 裕彦*; 広田 克也*; et al.
JPS Conference Proceedings (Internet), 33, p.011116_1 - 011116_6, 2021/03
中性子基礎物理学において、パリティ非保存(PNC)項や時間反転非保存項と干渉する中性子スピン
と標的核スピン
の相関項
は重要な研究テーマである。中性子共鳴ピーク付近でPNC項の増大が測定され、スピン交換光ポンピング(SEOP)法により
の偏極が得られるキセノン(Xe)は、本研究にとって興味深い原子核である。我々は小型SEOPシステムを用いた偏極Xe標的を開発し、核破砕中性子源で得られる大強度の熱外中性子ビームを利用した項の研究を計画している。その第一段階として、我々は
Xeの9.6eV共鳴ピーク付近でのXe偏極時と非偏極時の中性子透過率比の変化
を捕らえることで、項に起因する中性子偏極能力の測定をJ-PARC物質・生命科学実験施設(MLF)のBL10で試みた。実験では、本測定系がドップラーブロードニングの影響(
)を検知できることを実証した上で、初期結果として有意なの値を得ている。現在はをより詳細に評価するために、核磁気・電子スピン共鳴法によるXe偏極度の導出を進めている。
identification method by the 
reaction for a 
scattering experiment at J-PARC坂尾 珠和*; 藤田 真奈美; 長谷川 勝一; 細見 健二; 市川 真也; 市川 裕大; 今井 憲一*; 七村 拓野; 成木 恵; 佐甲 博之; et al.
JPS Conference Proceedings (Internet), 33, p.011133_1 - 011133_6, 2021/03
The reaction is an important elementary process to produce from a proton target and is a key for a scattering experiment where the momentum of should be tagged from the missing momentum of the 
reaction. However, the spectroscopy method has not been established yet due to the difficulty of the 
detection. Therefore, we have proposed a new detection method where 
and 
from the decay are measured by a forward magnetic spectrometer and a detector cluster surrounding the target, respectively. The feasibility of the detection method was confirmed by analyzing the J-PARC E40 data taken with such a detector system. In the analysis, 's were successfully identified in the missing mass spectrum of the 
reaction.
山本 直樹*; 古府 麻衣子; 中島 健次; 中川 洋; 柴山 修哉*
Journal of Physical Chemistry Letters (Internet), 12(8), p.2172 - 2176, 2021/03
被引用回数：3 パーセンタイル：48.7(Chemistry, Physical)水和水は、機能発現に必要な蛋白質のダイナミクスを活性化するために重要な役割を果たしている。しかし、水和水がどのようにして蛋白質のダイナミクスと結びついているのか、その詳細は不明である。水和水の氷形成の温度ヒステリシスは、凍結不可能な水和水と凍結可能な水和水のどちらのタイプの水和水が蛋白質ダイナミクスの活性化に重要な役割を果たしているのかを理解するための鍵となる現象である。中性子散乱を用いて、凍結可能な水和水の氷の回折ピークに温度ヒステリシス現象が観測されたのに対し、蛋白質ダイナミクスでは温度ヒステリシスは観測されなかった。これらの結果から、蛋白質のダイナミクスは凍結可能な水和水のダイナミクスとは連動しておらず、蛋白質のダイナミクスの活性化には凍結不可能な水和水が不可欠であることが明らかになった。
-
N system早川 修平; 藤田 真奈美; 長谷川 勝一; 橋本 直; 細見 健二; 市川 裕大; 今井 憲一*; 七村 拓野; 成木 恵; 佐甲 博之; et al.
Physical Review Letters, 126(6), p.062501_1 - 062501_6, 2021/02
被引用回数：27 パーセンタイル：97.14(Physics, Multidisciplinary)In an emulsion-counter hybrid experiment performed at J-PARC, a absorption event was observed which decayed into twin single- hypernuclei. Kinematic calculations enabled a unique identification of the reaction process as 
N
Be + 
He. For the binding energy of the 
hyperon in the -N system a value of 
MeV was deduced. The energy level of is likely a nuclear 
state which indicates a weak 
- coupling.
O by 
inelastic neutron scattering and their reactivity with ethylene山添 誠司*; 山本 旭*; 細川 三郎*; 福田 良一*; 原 賢二*; 中村 充孝; 蒲沢 和也*; 佃 達哉*; 吉田 寿雄*; 田中 庸裕*
Catalysis Science & Technology, 11(1), p.116 - 123, 2021/01
被引用回数：4 パーセンタイル：43.05(Chemistry, Physical)Hydrogen (H) species adsorbed on catalyst surfaces are key intermediates in catalytic hydrogenation reactions over supported metal catalysts. However, individual identification of H species on the metal catalysts has not been established to date. Here, we elucidated the H species on Pt/AlO by the combination of inelastic neutron scattering (INS) and density functional theory (DFT). Several H species in the presence of H were successfully identified at different sites on the Pt surface and AlO support. The INS and FT-IR measurements revealed that the hydride/atop Pt-H, bridged perimeter/terrace Pt-H-Pt, and threefold Pt-H are active intermediates in the CH
hydrogenation reaction, whereas the edge Pt-H-Pt is a rather inert species. In addition, the measurements indicate that the AlO itself acts as hydrogen storage material by mediating AlO-H and Al-H-Al species, which serve H species in the CH hydrogenation reaction.
hypernuclear spectroscopy with the 
reaction後神 利志*; 藤田 真奈美; 長谷川 勝一; 細見 健二; 今井 憲一*; 市川 裕大; 七村 拓野; 成木 恵; 佐甲 博之; 佐藤 進; et al.
Journal of Physics; Conference Series, 1643, p.012133_1 - 012133_6, 2020/12
被引用回数：0 パーセンタイル：0.09We performed hypernuclear spectroscopy with the reaction at J-PARC to investigate the 
interaction (J-PARC E05). A new experiment (J-PARC E70) in which a better energy resolution could be achieved is now being prepared. In this article, an analysis status of J-PARC E05 and a preparation status of J-PARC E70 are described.
interaction from the 
scattering experiment at J-PARC三輪 浩司*; 藤田 真奈美; 長谷川 勝一; 細見 健二; 市川 真也; 市川 裕大; 今井 憲一*; 七村 拓野; 成木 恵; 佐甲 博之; et al.
Journal of Physics; Conference Series, 1643, p.012174_1 - 012174_6, 2020/12
被引用回数：2 パーセンタイル：88.4A high statistics scattering experiment has been performed at the K1.8 beamline in the J-PARC Hadron Experimental Facility. Data for momentum-tagged 
beam running in a liquid hydrogen target were accumulated by detecting the 
reaction with a high intensity beam of 20 M/spill. The number of the beam was about 
in total. The 
elastic scattering and the 
inelastic scattering events were successfully observed with about 100 times larger statistics than that in past experiments.
SiO
(GPS) scintillator-based alpha imaging detector for rapid plutonium detection in high-radon environments森下 祐樹; 井崎 賢二; 金子 純一*; 山本 誠一*; 樋口 幹雄*; 鳥居 建男
IEEE Transactions on Nuclear Science, 67(10), p.2203 - 2208, 2020/10
被引用回数：6 パーセンタイル：67.23(Engineering, Electrical & Electronic)GdSiO(GPS)シンチレータベースの
線イメージング検出器を開発し、実際のプルトニウム(Pu)粒子と
Rn子孫核種を測定することにより、Rn子孫核種存在下でのPu粒子検知の有効性を実証した。GPSシンチレータプレートの外形寸法は5
5cmで、シンチレータ層は厚さ3mmの高透明ガラス上に構成され、シンチレータ層の厚みは約50ミクロンであった。シンチレータプレートは、位置感知型光電子増倍管にシリコーングリースで光学的に結合した。開発した線イメージング検出器は良好な感度の均一性を示した。Pu粒子の放射能を検出器上の14か所の異なる位置で評価した。測定した線のカウントから放射能は正確に評価され、その差異は6%以内となった。Pu同位体の線エネルギー領域にエネルギーウィンドウを適用することにより、ラドン222子孫核種のカウントを65.3%減少することができた。Pu/Rn子孫放射能比は1/51であったが、Pu粒子は5分測定でRn子孫核種から識別された。したがって、開発した線イメージング検出器は、高いラドンバックグラウンド環境下でのでのPu粒子の汚染のモニタリングに有効である。
He neutron spin filter at J-PARC奥平 琢也; 奥 隆之; 猪野 隆*; 林田 洋寿*; 吉良 弘*; 酒井 健二; 廣井 孝介; 高橋 慎吾*; 相澤 一也; 遠藤 仁*; et al.
Nuclear Instruments and Methods in Physics Research A, 977, p.164301_1 - 164301_8, 2020/10
被引用回数：8 パーセンタイル：83(Instruments & Instrumentation)We are developing a neutron polarizer with polarized He gas, referred to as a He spin filter, based on the Spin Exchange Optical Pumping (SEOP) for polarized neutron scattering experiments at Materials and Life Science Experimental Facility (MLF) of Japan Proton Accelerator Research Complex (J-PARC). A He gas-filling station was constructed at J-PARC, and several He cells with long spin relaxation times have been fabricated using the gas-filling station. A laboratory has been prepared in the MLF beam hall for polarizing He cells, and compact pumping systems with laser powers of 30 W and 110 W, which can be installed onto a neutron beamline, have been developed. A He polarization of 85% was achieved at a neutron beamline by using the pumping system with the 110 W laser. Recently, the first user experiment utilizing the He spin filter was conducted, and there have been several more since then. The development and utilization of He spin filters at MLF of J-PARC are reported.
佐藤 伸*; 大野 宏和; 棚井 憲治; 山本 修一*; 深谷 正明*; 志村 友行*; 丹生屋 純夫*
地盤工学ジャーナル(インターネット), 15(3), p.529 - 541, 2020/09
本検討は、幌延深地層研究センターで実施中の人工バリア性能確認試験を対象に、熱・水・応力連成解析を実施した。再冠水時の熱・水・応力連成挙動は、間隙水の加熱により生じる水蒸気や、間隙圧の上昇により生じる気相の液相への溶解等の相変換の影響を受けると考えられる。そこで、相変換可能な熱・水・応力連成解析を実施し、水蒸気の発生や間隙空気の間隙水への溶解が再冠水挙動にどのような影響を及ぼすのか考察した。その結果、水蒸気を考慮することにより、ヒーター周辺の間隙率が増大し、乾燥密度の分布が生じた。さらに、気液二相流パラメータを変化させると緩衝材の応力状態が変化し、それに伴い、膨潤による緩衝材の膨出量にも影響を及ぼした。このため、緩衝材の長期挙動評価のうち再冠水挙動を模擬するには、相変換を考慮する必要があり、さらに、精緻な予測を行うためには、気液二相流パラメータの評価が重要であることが分かった。
