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Gd and 
Gd in the thermal energy region with the Li-glass detectors and NaI(Tl) spectrometer installed in J-PARC
MLFANNRI木村 敦; 中村 詔司; 遠藤 駿典; Rovira Leveroni, G.; 岩本 修; 岩本 信之; 原田 秀郎; 片渕 竜也*; 寺田 和司*; 堀 順一*; et al.
Journal of Nuclear Science and Technology, 60(6), p.678 - 696, 2023/06
被引用回数：2 パーセンタイル：53.91(Nuclear Science & Technology)Neutron total and capture cross-section measurements of Gd and Gd were performed in the ANNRI at the MLF of the J-PARC. The neutron total cross sections were determined in the energy region from 5 to 100 meV. At the thermal neutron energy, the total cross sections were obtained to be 59.4
1.7 and 251.94.6 kilobarn for Gd and Gd, respectively. The neutron capture cross sections were determined in the energy region from 3.5 to 100 meV with an innovative method by taking the ratio of the detected capture event rate between thin and thick samples. At the thermal energy, the capture cross sections were obtained as 59.02.5 and 247.43.9 kilobarn for Gd and Gd, respectively. The present total and capture cross sections agree well within the standard deviations. The results for Gd were found to be consistent with the values in JENDL-4.0 and the experimental data given by Mastromarco et al. and Leinweber et al. within one standard deviation. Moreover, the present results for Gd agreed with the evaluated data in JENDL-4.0 and the experimental data by M
ller et al. within one standard deviation and agreed with the data by Mastromarco et al. within 1.4 standard deviations. However, they disagree (11% larger) with the experimental result by Leinweber et al.
片渕 竜也*; 岩本 修; 堀 順一*; 木村 敦; 岩本 信之; 中村 詔司; Rovira Leveroni, G.; 遠藤 駿典; 芝原 雄司*; 寺田 和司*; et al.
EPJ Web of Conferences, 281, p.00014_1 - 00014_4, 2023/03
Long-lived minor actinides (MA) in nuclear waste from nuclear power plants are a long-standing issue to continue nuclear energy production. To solve the issue, researchers have suggested nuclear transmutation, in which long-lived radionuclides are transmuted into stable or shorter-life nuclides via neutron-induced nuclear reactions. Development of nuclear transmutation systems as an accelerator-driven system requires accurate neutron nuclear reaction data. The present research project entitled "Study on accuracy improvement of fast-neutron capture reaction data of long-lived MAs for development of nuclear transmutation systems" have been conducted as a joint collaboration, including Tokyo Tech, Japan Atomic Energy Agency and Kyoto University. This project focuses on the neutron capture reaction of MAs, especially 
Np, 
Am and 
Am, in the fast neutron energy region. The final goal of this project is to improve the accuracies of the neutron capture cross sections of Np, Am and Am employing a high-intensity neutron beam from a spallation source of the Japan Proton Accelerator Research Complex (J-PARC) that reduces uncertainties of measurement. To achieve the goal, a neutron beam filter system in J-PARC, sample characteristic assay, and theoretical reaction model study were developed. In this contribution, the overview and results of the project will be presented.
Au with a Cr-filtered neutron beam at the ANNRI beamline of MLF/J-PARCRovira Leveroni, G.; 木村 敦; 中村 詔司; 遠藤 駿典; 岩本 修; 岩本 信之; 片渕 竜也*; 児玉 有*; 中野 秀仁*; 佐藤 八起*; et al.
Journal of Nuclear Science and Technology, 59(5), p.647 - 655, 2022/05
被引用回数：1 パーセンタイル：16.35(Nuclear Science & Technology)Cr-filtered keV-neutron experiments were performed in the Accurate Neutron-Nucleus Reaction Measurement Instrument (ANNRI) beamline in the Materials and Life Science (MLF) facility of the Japan Proton Accelerator Research Complex (J-PARC) to measure the neutron capture cross-section of Au. The energy range of the neutron filtering system at ANNRI was extended through the use of 15 cm of 
Cr as filter material to tailor quasi-monochromatic neutron peaks with averaged neutron energies of 133.4 and 45.0 keV. The performance of the Cr filter assembly was evaluated by means of experimental capture and transmission analyses, together with the use of Monte-Carlo simulations. The present Au neutron capture cross-section results provide agreement within uncertainties with the JENDL-4.0 standard evaluated library and the IAEA standard data library further demonstrating the capabilities of the neutron filtering system at ANNRI.
Rovira Leveroni, G.; 岩本 修; 木村 敦; 中村 詔司; 岩本 信之; 遠藤 駿典; 片渕 竜也*; 寺田 和司*; 児玉 有*; 中野 秀仁*; et al.
JAEA-Conf 2021-001, p.156 - 161, 2022/03
A neutron filtering system has been designed in order to bypass the double-timed structure of the beam. Filter materials were introduced into the rotary collimator of the ANNRI beamline in order to produce quasi-monoenergetic neutron filtered beams. Filter assemblies consisting of Fe with a thickness of 20 cm, and Si with thicknesses of 20 cm and 30 cm of Si were used separately to produce filtered neutron peaks with energies of 24 keV (Fe) and of 54 and 144 (Si). In this study, the characteristics and performance of the neutron filtering system at ANNRI using Fe and Si determined from both measurements and simulations are presented. The incident neutron flux was tested and analyzed by means of transmission and capture experiments. Moreover, simulations using the PHITS code were performed in order to determine the energy distribution of the integrated filtered peaks and assess the reliability of experimental results. Finally, preliminary results of the capture cross section of Au at the filtered energies of 24, 54 and 144 keV are also presented using the NaI(Tl) spectrometer alongside the neutron filtering system.
Am around 23.5 keV児玉 有*; 片渕 竜也*; Rovira Leveroni, G.; 木村 敦; 中村 詔司; 遠藤 駿典; 岩本 信之; 岩本 修; 堀 順一*; 芝原 雄司*; et al.
Journal of Nuclear Science and Technology, 58(11), p.1159 - 1164, 2021/11
被引用回数：4 パーセンタイル：56.94(Nuclear Science & Technology)The neutron capture cross section of Am was measured with a pulsed neutron beam from a spallation neutron source of the Japan Proton Accelerator Research Complex. A Fe neutron beam filter was used to make the incident neutron beam mono-energetic around 23.5 keV. The neutron capture 
-rays were detected with a NaI(Tl) detector. The pulse height weighting technique was employed to derive the neutron capture cross section from the pulse height spectrum. The cross section was determined relative to the capture cross section of Au of JENDL-4.0. The neutron capture cross section of Am was determined with a smaller uncertainty than previous measurements. The previous measurements and the JENDL-4.0 cross sections were found to be lower than the present result.
Rovira Leveroni, G.; 木村 敦; 中村 詔司; 遠藤 駿典; 岩本 修; 岩本 信之; 片渕 竜也*; 寺田 和司*; 児玉 有*; 中野 秀仁*; et al.
Nuclear Instruments and Methods in Physics Research A, 1003, p.165318_1 - 165318_10, 2021/07
被引用回数：4 パーセンタイル：57.13(Instruments & Instrumentation)A neutron filtering system has been introduced in the Accurate Neutron-Nucleus Reaction Measurement Instrument (ANNRI) beamline in the Material and Life Science (MLF) building of the Japan Proton Accelerator Research Complex (J-PARC) in order to produce quasi-monoenergetic neutron beams. The filtered neutron spectrum by the filter assemblies was analyzed by means of capture and transmission measurements and also by Monte Carlo simulations using PHITS. The characteristics of the filtered neutron beam are discussed alongside its viability in future applications for neutron cross-section measurements in the fast neutron region.
He spin filter at a pulsed neutron source奥平 琢也; 上田 祐生; 廣井 孝介; 元川 竜平; 稲村 泰弘; 高田 慎一; 奥 隆之; 鈴木 淳市*; 高橋 慎吾*; 遠藤 仁*; et al.
Journal of Applied Crystallography, 54(2), p.548 - 556, 2021/04
被引用回数：2 パーセンタイル：33.1(Chemistry, Multidisciplinary)Heスピンフィルタを中性子スピン解析子として使用することにより、パルス中性子源での中性子小角散乱実験において、偏極解析を行うことに成功した。本実験に使用したHeスピンフィルタは中性子小角散乱実験を行うために十分な立体角をカバーすることができ、He偏極緩和時間も数日と長く、これは実験を完遂するために十分な性能である。水素原子による非干渉性散乱は非常に大きく、試料の組成から計算によって非干渉性散乱量を見積もる試みが行われていたが、正確に非干渉性散乱量を決定することは難しかった。しかし本研究では試料内での中性子の多重散乱を考慮した偏極解析実験を行うことで、干渉性散乱と非干渉性散乱を正確に分離することが可能となった。現在までパルス中性子源での中性子小角散乱では、偏極解析の手法が確立されていなかったが、本成果によって、様々な種類の試料に対して干渉性散乱と非干渉性散乱を正確に分離することができるようになると予想される。
片渕 竜也*; 堀 順一*; 岩本 信之; 岩本 修; 木村 敦; 中村 詔司; 芝原 雄司*; 寺田 和司*; 登坂 健一*; 遠藤 駿典; et al.
JAEA-Conf 2020-001, p.5 - 9, 2020/12
A research project entitled "Study on accuracy improvement of fast-neutron capture reaction data of long-lived MAs for development of nuclear transmutation systems" has been ongoing since 2017. The project aims at improving accuracy of neutron capture cross sections of long-lived minor actinides (MAs; Np and 
Am) in the fast neutron energy region which are very important for development of nuclear transmutation systems. In order to improve the capture reaction data of MAs, measurements using an intense pulsed neutron beam from a spallation neutron source of J-PARC are planned. The project consists of four parts: (1) development of neutron beam filter system, (2) cross section measurement, (3) sample characteristic assay, and (4) theoretical study. The filter system is designed to solve a double bunch issue in J-PARC. The sample characteristic assay lowers systematic uncertainties originating the samples. In the theoretical study, a nuclear reaction model is applied to analyzing cross sections and -ray spectra measured in experiments. The outline of the project and the current progress will be presented.
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：10 パーセンタイル：79.13(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.
中島 健次; 川北 至信; 伊藤 晋一*; 阿部 淳*; 相澤 一也; 青木 裕之; 遠藤 仁*; 藤田 全基*; 舟越 賢一*; Gong, W.*; et al.
Quantum Beam Science (Internet), 1(3), p.9_1 - 9_59, 2017/12
J-PARC物質・生命科学実験施設の中性子実験装置についてのレビューである。物質・生命科学実験施設には23の中性子ビームポートがあり21台の装置が設置されている。それらは、J-PARCの高性能な中性子源と最新の技術を組み合わせた世界屈指の実験装置群である。このレビューでは、装置性能や典型的な成果等について概観する。
Yagmur, A.*; 内田 健一*; 井原 和紀*; 井岡 郁夫; 吉川 貴史*; 小野 円佳*; 遠藤 純一*; 柏木 王明*; 中島 哲也*; 桐原 明宏*; et al.
Applied Physics Letters, 109(24), p.243902_1 - 243902_4, 2016/12
被引用回数：3 パーセンタイル：14.94(Physics, Applied)スピンゼーベック効果(SSE)に基づく熱電素子の線抵抗性を調べるため、約3
10
Gyの線照射試験を実施した。SSE素子には、Pt/Ni
Zn
Fe
O
/GlassとPt/Bi
Y
Fe
O
/Gd
GaOを用いた。SSE素子の熱電特性,磁気特性、構造は、線照射により影響されないことを確認した。この結果は、SSE素子が厳しい照射環境でさえ熱電素子として適用可能なことを示した。
豊岡 淳一; 遠藤 寛*; 飛田 吉春; 高橋 実*
日本原子力学会和文論文誌, 13(2), p.35 - 50, 2014/05
本研究では、次世代ナトリウム冷却高速増殖炉として、炉心損傷事故時に溶融燃料を炉心外に排除することにより再臨界を回避する目的で燃料集合体内部に溶融燃料を流出する経路(内部ダクト)を設けたFAIDUS集合体を採用しているJSFRについて、FAIDUS集合体の再臨界排除機能の原理的有効性を確認し、内部ダクト壁の早期・高熱流束破損に関する伝熱機構を明らかにすることを目的とし、溶融燃料を内部ダクトの破損により排除する機能を確認するための実機模擬性の高い試験での試験データに基づいた解析的研究を実施した。その結果、初めて機構論的なモデルでID1試験の早期ダクト破損を説明できる結果を得た。また、本試験解析を通じて、高速炉の再臨界問題を解決するうえで重要となるダクト破損に至る過程の物理メカニズムの解明を進めた
豊岡 淳一; 遠藤 寛*; 飛田 吉春; 二ノ方 壽*
日本原子力学会和文論文誌, 12(1), p.50 - 66, 2013/03
本研究では、FBRにおいて炉心損傷事故が発生した場合でも、燃料集合体内に設置した内部ダクトを介して溶融燃料を炉心外に排出し厳しい再臨界を防止する設計対策(FAIDUS)の原理的有効性を確認する観点から、カザフスタンIGR炉で実施されたID1試験結果に伝熱挙動解析コードTAC2D及び炉心損傷事故解析コードSIMMER-IIIを適用し、高温融体と接触したダクト壁の伝熱・破損機構を明らかにする目的で体系的な伝熱挙動評価を行った。本研究で得られた知見から、ID1試験で見いだされたダクト壁の早期の高熱流束破損機構はFAIDUS集合体への要求条件「炉心損傷事故時に燃料集合体のラッパ壁が破損する以前の早期段階においてFAIDUS集合体の内部ダクト壁が破損し、燃料集合体内に生成された溶融燃料が集合体外に流出すること。」を大略満足し、FAIDUS概念の原理的成立性を支持していると判断される。
木下 淳一; 遠藤 誠之; 上坂 貴洋
JAEA-Testing 2012-003, 29 Pages, 2012/11
JAEA-Testing-2012-003.pdf:2.95MB
第2廃棄物処理棟のアスファルト固化装置では原子力科学研究所内から発生する比較的放射能濃度の高い放射性液体廃棄物をアスファルトと混練し、アスファルト固化体を作製しており、作製されたアスファルト固化体は、将来、均質固化体として浅地中埋設処分される予定である。均質固化体の埋設処分にかかわる法令上の技術基準上においては固型化材料と放射性廃棄物を均質に練り混ぜることが要求されており、この要求に対応するためにはアスファルト固化装置が均質な練り混ぜ性能を有することの確認が必要である。本稿は、第2廃棄物処理棟のアスファルト固化装置で混練した混合物の密度及び放射能濃度測定を行い、練り混ぜ性能を確認して、将来の埋設処分の基礎データとして活用するものである。
上坂 貴洋; 小澤 政千代; 松本 潤子; 遠藤 誠之; 木下 淳一; 鈴木 武; 鈴木 久雄; 森下 悟; 坂本 裕
JAEA-Technology 2012-015, 29 Pages, 2012/06
JAEA-Technology-2012-015.pdf:3.22MB
日本原子力研究開発機構原子力科学研究所第2廃棄物処理棟の固体廃棄物処理設備・IIでは、放射線量の高い固体廃棄物の処理を行っている。固体廃棄物は圧縮減容され、封入容器に収納し、必要に応じた補充しゃへい体を選定付加したコンクリートを内巻した200Lのドラム缶若しくは1mのコンクリート製の容器(以下、しゃへい容器という。)に収納している。なお、しゃへい容器は、上部にコンクリートを注入する構造となっている。将来の埋設処分に備え、廃棄体の技術基準に適合させるための対応が可能となるよう、しゃへい容器に収納した固体廃棄物を容易に取り出せる構造とする蓋方式のしゃへい容器への変更が求められたため、蓋式しゃへい容器の変更にあたり、落下解析による蓋締めボルトの評価、しゃへい計算による評価を行い、設計・製作した試作品による落下試験を実施して、新たに使用する蓋式しゃへい容器の健全性を確認した。
Cu
N
O
as seen via resonant inelastic X-ray scattering石井 賢司; 筒井 健二; 池内 和彦*; Jarrige, I.; 水木 純一郎; 平賀 晴弘*; 山田 和芳*; 遠山 貴己*; 前川 禎通; 遠藤 康夫*; et al.
Physical Review B, 85(10), p.104509_1 - 104509_5, 2012/03
被引用回数：3 パーセンタイル：14.91(Materials Science, Multidisciplinary)We perform a resonant inelastic X-ray scattering (RIXS) study of Ni-substituted LaCuO and Cu-substituted LaNiO.Resonantly enhanced charge-transfer excitations are successfully observed by tuning the incident photon energy to the 
-edge of the substituted element. These excitations display a very weak momentum dependence, evidencing their local character. We find a shift in the energy of the onset edge of these features compared with the non-substituted compounds LaCuO and LaNiO. This shift is quantitatively reproduced by exact diagonalization calculations of the RIXS spectra. RIXS is shown to be a powerful tool to probe the electronic states of substituted elements and to understand their interaction with surrounding atoms.
He neutron spin filter in Japan吉良 弘; 坂口 佳史; 奥 隆之; 鈴木 淳市; 中村 充孝; 新井 正敏; 遠藤 康夫; Chang, L.-J.; 加倉井 和久; 有本 靖*; et al.
Journal of Physics; Conference Series, 294, p.012014_1 - 012014_5, 2011/06
被引用回数：11 パーセンタイル：94.52(Physics, Applied)The pulsed neutron source of J-PARC has started to operate in 2008 in Japan. To study structure of magnetic material and soft matters, polarized neutron scattering techniques are very important and powerful tools. It is urgently necessary for us to develop neutron spin polarizers for pulsed neutron scattering experiments. So we began the development of the in-situ SEOP system aiming to use it as a NSF for incident beam polarization and polarization analysis. In previous test performed by Ino et al., the He polarization reached 50% and not saturated yet. After that experiment, we began improving the SEOP system by installing the high power laser diode, the prism beam splitter and optimizing the beam-transform optics. By using this improved system, we performed the polarization test at BL10 in J-PRC and achieved the He polarization of 73%. We keep improving this in-situ SEOP system aiming to use it s an incident neutron polarizer at J-PARC.
He neutron spin filters on the small-angle neutron scattering spectrometer SANS-J-II坂口 佳史; 吉良 弘; 奥 隆之; 篠原 武尚; 鈴木 淳市; 酒井 健二; 中村 充孝; 相澤 一也; 新井 正敏; 能田 洋平; et al.
Journal of Physics; Conference Series, 294(1), p.012017_1 - 012017_7, 2011/06
被引用回数：2 パーセンタイル：65.52(Physics, Applied)A polarized He neutron spin filter has been applied to polarization analysis on the small-angle neutron scattering spectrometer SANS-J-II at JRR-3. Measurements were taken on silver behenate, which has several coherent peaks in the small-angle region with a background of spin incoherent hydrogen scattering. Here we demonstrate that the coherent and spin incoherent scattering were successfully separated by the polarization analysis using the He spin filter on the instrument.
He neutron spin filter cells坂口 佳史; 吉良 弘; 奥 隆之; 篠原 武尚; 鈴木 淳市; 酒井 健二; 中村 充孝; 鈴谷 賢太郎; 相澤 一也; 新井 正敏; et al.
Journal of Physics; Conference Series, 294(1), p.012004_1 - 012004_7, 2011/06
被引用回数：2 パーセンタイル：65.52(Physics, Applied)In spin-exchange optical pumping, there is unknown excess relaxation, called the X-factor, that limits attainable He polarization. It is known that the X-factor depends on the glass containers. Hence, it is expected that there are cell-to-cell variations in microscopic structure among the cells and that these variations affect the attainable He polarization. However, microscopic structure of the glasses for He neutron spin filters has not been clarified yet. In this paper, we have performed precise X-ray diffraction measurements for the glasses at SPring-8 using synchrotron radiation. The structural differences are observed between several types of glasses, and also, between the GE180 glass pieces with different thermal treatment. Based on the results, the structural influence on the performance of He neutron spin filters is discussed.
吉良 弘; 坂口 佳史; 奥 隆之; 鈴木 淳市; 中村 充孝; 新井 正敏; 加倉井 和久; 遠藤 康夫; 有本 靖*; 猪野 隆*; et al.
Physica B; Condensed Matter, 406(12), p.2433 - 2435, 2011/06
被引用回数：8 パーセンタイル：36.17(Physics, Condensed Matter)Polarized neutron scattering techniques are very important and powerful tools to study the fundamental structures of magnetic materials and soft matters. He has a very large absorption cross section for only neutrons in opposite spin state to that of the He nucleus. The scattering cross section of He is small. These two features allow nuclear spin polarized He gas to work as a NSF. Compared with other spin filters such as Heusler alloys and magnetic supermirrors, the He gas NSF have following advantages: it can polarize various energy of neutron such as cold, thermal and hot neutrons, it can work for broadband neutrons and it can be used for wide area and large divergence neutron beams. These characteristics of polarized He are convenient in use with J-PARC as NSF. We began the development of the on beam SEOP system aiming to use it s a NSF for incident beam polarisation and polarisation analysis. In this paper, we report the current development of SEOP system in Japan.
