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Lee, J.; Rossi, F.; 児玉 有; 弘中 浩太; 小泉 光生; 佐野 忠史*; 松尾 泰典*; 堀 順一*
Annals of Nuclear Energy, 211, p.111017_1 - 111017_7, 2025/02
被引用回数：0 パーセンタイル：0.00(Nuclear Science & Technology)Silica glass has been used as a base and host material in vitrified radioactive waste and lithium glass scintillator for neutron detection because of its superb transparency, high heat resistance, and excellent chemical inertness. Therefore, an accurate total cross section of the silica glass is important to evaluate the criticality safety for the vitrified wastes and to understand the neutron response for lithium glass scintillators accurately. In the present study, to provide the accurate total cross section in the thermal and epithermal energy range, the neutron transmission measurements were carried out by a pulsed neutron beam with the time-of-flight method at the Kyoto University Institute for Integrated Radiation and Nuclear Science - Linear Accelerator. We obtained the neutron total cross section of the silica glass in the energy region from 0.002 eV to 25 eV. The obtained results were compared and discussed with the previous results and the evaluated data.
小手川 恒*; 中村 彰良*; Huyen, V. T. N.*; 新井 祐樹*; 藤 秀樹*; 菅原 仁*; 林 純一*; 武田 圭生*; 田端 千紘; 金子 耕士; et al.
Physical Review B, 110(21), p.214417_1 - 214417_8, 2024/12
被引用回数：0 パーセンタイル：0.00(Materials Science, Multidisciplinary)In this study, we show that the orthorhombic system TaMnP exhibits a large anomalous Hall conductivity (AHC) in spite of the small net magnetization. Neutron scattering experiment and the observation of the AH effect comprehensively suggest a dominant AF structure in TaMnP is represented by 
. The AHC is one of the largest among those observed in AF materials at zero fields. First-principles calculations suggest that the spin-orbit interaction originating in nonmagnetic Ta-5
electrons significantly contributes to the enhancement of Berry curvatures in the momentum space. We found that the AF domain switching is triggered by the magnetic fields along all the crystal axes. This indicates that the AF domain determining the sign of the Hall response can be controlled even through the small net magnetization symmetrically different.
Lan, Z.*; 有川 安信*; Mirfayzi, S. R.*; Morace, A.*; 早川 岳人*; 佐藤 博隆*; 加美山 隆*; Wei, T.*; 巽 湧太*; 小泉 光生; et al.
Nature Communications (Internet), 15, p.5365_1 - 5365_7, 2024/07
被引用回数：5 パーセンタイル：75.95(Multidisciplinary Sciences)The temperature measurement of material inside of an object is one of the key technologies for control of dynamical processes. For this purpose, various techniques such as laser-based thermography and phase-contrast imaging thermography have been studied. However, it is, in principle, impossible to measure the temperature of an element inside of an object using these techniques. One of the possible solutions is measurements of Doppler brooding effect in neutron resonance absorption (NRA). Here we present a method to measure the temperature of an element or an isotope inside of an object using NRA with a single neutron pulse of approximately 100 ns width provided from a high-power laser. We demonstrate temperature measurements of a tantalum (Ta) metallic foil heated from the room temperature up to 617 K. Although the neutron energy resolution is fluctuated from shot to shot, we obtain the temperature dependence of resonance Doppler broadening using a reference of a silver (Ag) foil kept to the room temperature. A free gas model well reproduces the results. This method enables element(isotope)-sensitive thermometry to detect the instantaneous temperature rise in dynamical processes.
Rossi, F.; Lee, J.; 児玉 有; 弘中 浩太; 小泉 光生; 堀 順一*; 寺田 和司*; 佐野 忠史*
Proceedings of 65th Annual Meeting of the Institute of Nuclear Materials Management (Internet), 8 Pages, 2024/07
Various non-destructive assay techniques are being used to verify different nuclear material. However, one of the difficulties of current NDA is the measurement of highly radioactive materials. Since 2015, the JAEA has been working on the development of various active non-destructive assay techniques to address some of the current challenges in nuclear safeguards. Among the various technologies proposed, the Neutron Resonance Analysis system combines signatures from NRTA, NRCA and the newly proposed NRFNA. The combination of those techniques can provide accurate information on the small fissile content in a sample. Neutrons are generated by a pulsed neutron source and slowed down into the moderator. Neutrons are collimated using lead and borated polyethylene to reach the sample, where various neutron-induced reactions occur. n/g PSD plastic scintillators are used to measure the captured gamma rays and fission neutrons at sample location. GS20 is used to collect the transmitted neutrons downstream of the source-sample beamline. A first measurement campaign was performed using natural uranium sample. The possibility of using NRFNA to identify fissile materials within a sample was clearly demonstrated, but the detectors used were not sufficient to achieve a good n/g PSD. New PSD scintillators were introduced. A first measurement campaign was performed in 2023. The acquired data are currently being analyzed, but preliminary results show distinct fission resonance peaks of increasing intensity with varying thicknesses of the same natural uranium samples. Currently, an assembly of multiple scintillators is being investigated to provide a better signal. The new setup will be tested starting in early 2024. In this paper, we will describe in detail the NRA project development and the latest results from experimental campaign. This work is supported by MEXT under the subsidy for the "promotion for strengthening nuclear security and the like"
Am neutron capture cross section measurement using the NaI(Tl) spectrometer of the ANNRI beamline of 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*
Journal of Nuclear Science and Technology, 61(4), p.459 - 477, 2024/04
被引用回数：1 パーセンタイル：23.64(Nuclear Science & Technology)The neutron capture cross-section of Am was measured from 10 meV to about 1 MeV using the NaI(Tl) spectrometer of 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). The total energy detection principle was applied in conjunction with the pulse-height weighting technique to derive the neutron capture yield. The present cross-section results were normalized using a 
Au sample measurement by applying the saturated resonance method. The thermal cross section was measured to be 708 
22 b, in agreement within uncertainties to the present evaluation in JENDL-5 of 709 b. Moreover, the results of a shape resonance analysis of the resolved resonance region are also provided in the present dissertation.
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。
金子 耕士; 田端 千紘; 萩原 雅人; 山内 宏樹; 大場 洋次郎; 熊田 高之; 久保田 正人; 児島 佑樹*; 生田目 望; 佐々木 未来; et al.
JPS Conference Proceedings (Internet), 41, p.011015_1 - 011015_6, 2024/03
We will introduce our recent update on low temperature system for neutron diffraction experiments. This is characterized by advantages such as liquid He free and sophisticated automatic temperature control functions, which can be a new standard for low temperature and high magnetic field experiments of neutron scattering.
CoSi山内 宏樹; Sari, D. P.*; 安井 幸夫*; 坂倉 輝俊*; 木村 宏之*; 中尾 朗子*; 大原 高志; 本田 孝志*; 樹神 克明; 井川 直樹; et al.
Physical Review Research (Internet), 6(1), p.013144_1 - 013144_9, 2024/02
-Mn-type family alloys Mn
have three-dimensional antiferromagnetic (AFM) corner-shared triangular network. The antiferromagnet MnRhSi shows magnetic short-range order (SRO) over a wide temperature range of approximately 500 K above the N
el temperature 
= 190 K. MnCoSi has the smallest lattice parameter and the lowest in the family compounds. The quantum critical point (QCP) from AFM to the quantum paramagnetic state is expected near a cubic lattice parameter of 6.15 
of MnCoSi is only 140 K, quantum critical behavior is observed in MnCoSi as the enhancement of the electronic specific heat coefficient 
. We study how the magnetic SRO appears in MnCoSi by using neutron scattering, 
SR, and physical property measurements. The experimental results show that the neutron scattering intensity of the magnetic SRO does not change much regardless of the suppressed magnetic moment in the long-range magnetic ordered state compared to those of MnRhSi. The initial asymmetry drop ratio of SR above becomes small, and the magnetic SRO temperature 
is suppressed to 240 K. The results suggest that the MnCoSi is close to the QCP in the Mn system.
Lee, J.; 児玉 有; Rossi, F.; 弘中 浩太; 小泉 光生; 堀 順一*; 佐野 忠史*
第44回日本核物質管理学会年次大会会議論文集(インターネット), 4 Pages, 2023/11
核不拡散・核セキュリティ総合支援センターでは、試料中に含まれる少量の核分裂性物質を特定し定量する能力を向上させるための技術として、中性子飛行時間法を用いた中性子共鳴核分裂中性子分析(Neutron Resonance Fission Neutron Analysis: NRFNA)の技術開発を進めている。本発表会では、核分裂性物質の非破壊分析のために進めているNRFNA技術の紹介及びその基礎実験の結果について報告する。
Pd using ANNRI at MLF/J-PARC中野 秀仁*; 片渕 竜也*; 寺田 和司*; 木村 敦; 中村 詔司; 遠藤 駿典; Rovira Leveroni, G.; 児玉 有*
EPJ Web of Conferences, 284, p.01032_1 - 01032_3, 2023/05
被引用回数：0 パーセンタイル：0.00(Nuclear Science & Technology)In the present work, the neutron capture cross section measurements were carried out using the Accurate Neutron Nucleus Reaction Measurement Instrument (ANNRI) at the Materials and Life Science Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC). A high intensity pulsed neutron beam from Japan Spallation Neutron Source at the MLF using the 3 GeV proton beam was utilized. NaI(Tl) detectors of ANNRI were used for capture measurements. The time-of-flight (TOF) method was employed to determine the incident neutron energy. Two-dimensional data, TOF and pulse-height (PH), were acquired and the data were analyzed based on a PH weighting technique. Resonance parameters were derived from resonance analysis using the REFIT code.
児玉 有*; 片渕 竜也*; Rovira Leveroni, G.; 木村 敦; 中村 詔司; 遠藤 駿典; 中野 秀仁*; 佐藤 八起*; 堀 順一*; 芝原 雄司*; et al.
EPJ Web of Conferences, 284, p.01024_1 - 01024_3, 2023/05
被引用回数：0 パーセンタイル：0.00(Nuclear Science & Technology)The measurements were performed using the Accurate Neutron-Nucleus Reaction Measurement Instrument (ANNRI) beamline at the Japan Proton Accelerator Research Complex (J-PARC). An intense pulsed neutron beam was produced via spallation reaction in the mercury target of the Material and Life Science Experimental Facility by the 3-GeV proton beam of the J-PARC facility. A Time of Flight (TOF) method using a NaI(Tl) detector was employed in this measurements and a pulse-height weighting technique was used to derive a neutron capture yield. A sample of Am-243 with a mass of 38.14 mg (281.8 MBq) was used for the measurements. The neutron energy spectrum was obtained by using the 478 keV gamma-rays from the 
B(n,
)
Li reaction with a boron sample. A preliminary value for the capture cross section of Am-243 will be presented in the contribution.
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*; 児玉 有*; 中野 秀仁*; 堀 順一*; et al.
EPJ Web of Conferences, 284, p.06007_1 - 06007_4, 2023/05
被引用回数：0 パーセンタイル：0.00(Nuclear Science & Technology)A neutron filtering system has been installed at the ANNRI beamline in order to bypass the doublet structure of the incident neutron beam in the keV region. Thick cylindrical slabs of 
Fe, Si and Cr which share the characteristic of a sharp minimum in the neutron total cross section, were separately introduced in an intermediate stage of the beamline, before the NaI(Tl) spectrometer experimental area. The filtered neutron beams were analyzed by means of both neutron capture and transmission experiments. Moreover, further information about the neutron energy distribution within the filtered peaks was derived through the use of Monte-Carlo simulations with the PHITS code. The characteristics of the filtered neutron beams for Fe, i and Cr are presented together with Au standard experimental results to assess the performance of the neutron filtering system in neutron capture cross section experiments.
Am neutron capture cross section in the keV region using Si and Fe-filtered neutron beamsRovira 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*
Journal of Nuclear Science and Technology, 60(5), p.489 - 499, 2023/05
被引用回数：3 パーセンタイル：41.50(Nuclear Science & Technology)The neutron capture cross-section of Am was measured in the keV neutron range using the recently implemented neutron filtering system of 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). Filter arrays consisting of 20 cm of Fe and Si were employed in separate measurements to provide filtered neutron beams with averaged neutron energies of 23.5 (Fe), 51.5 and 127.7 (Si) keV. The present Am results were obtained relative to the Au neutron capture yield by applying the total energy detection principle together with the pulse-height weighting technique. The Am neutron capture cross section was determined as 2.72 0.29 b at 23.5 keV, 2.14 0.26 b at 51.5 keV and 1.32 0.10 b at 127.7 keV with total uncertainties in the range of 8 to 12
, much lower in comparison to the latest time-of-flight experimental data available.
, Zr, and stainless steel and leaching behavior of the fission products and matrix elements頓名 龍太郎*; 佐々木 隆之*; 児玉 雄二*; 小林 大志*; 秋山 大輔*; 桐島 陽*; 佐藤 修彰*; 熊谷 友多; 日下 良二; 渡邉 雅之
Nuclear Engineering and Technology, 55(4), p.1300 - 1309, 2023/04
被引用回数：6 パーセンタイル：84.29(Nuclear Science & Technology)UO・Zr・ステンレス鋼を出発物質として模擬デブリを合成し、形成された固相の分析と浸漬試験を行った。主要なU含有相は合成条件に依存し、不活性雰囲気下・1473KではUO相が維持されていた。1873Kでは(U,Zr)O固溶体相の形成が観測された。酸化性雰囲気では、1473Kの場合にはU
O
と(Fe,Cr)UO
相の混合物が得られ、1873Kでは(U,Zr)Oが形成された。浸漬試験により金属イオンの溶出挙動を調べるため、中性子照射により核分裂生成物を導入する、もしくは出発物質への添加によりその安定同位体を導入する処理を行った。試験の結果、Uの溶出挙動は、模擬デブリの性状や浸漬液の液性に依存することが確認された。CsやSr, Baは模擬デブリの固相組成に依存せず顕著な溶出を示した。一方で、多価イオンとなるEuとRuの溶出は抑制されることが観測され、模擬デブリ中でウラン相に固溶ないしは包含されたことによる影響が推察される。
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.
余語 覚文*; Lan, Z.*; 有川 安信*; 安部 勇輝*; Mirfayzi, S. R.*; Wei, T.*; 森 隆人*; Golovin, D.*; 早川 岳人*; 岩田 夏弥*; et al.
Physical Review X, 13(1), p.011011_1 - 011011_12, 2023/01
被引用回数：28 パーセンタイル：96.01(Physics, Multidisciplinary)Neutrons are powerful tools for investigating the structure and properties of materials used in science and technology. Recently, laser-driven neutron sources (LDNS) have attracted the attention of different communities, from science to industry, in a variety of applications, including radiography, spectroscopy, security, and medicine. However, the laser-driven ion acceleration mechanism for neutron generation and for establishing the scaling law on the neutron yield is essential to improve the feasibility of LDNS. In this paper, we report the mechanism that accelerates ions with spectra suitable for neutron generation. We show that the neutron yield increases with the fourth power of the laser intensity, resulting in the neutron generation of 
in 
at a maximum, with 
Wcm
, 900 J, 1.5 ps lasers. By installing a "hand-size" moderator, which is specially designed for the LDNS, it is demonstrated that the efficient generation of epithermal (0.1-100 eV) neutrons enables the single-shot analysis of composite materials by neutron resonance transmission analysis (NRTA). We achieve the energy resolution of 2.3% for 5.19-eV neutrons 1.8 m downstream of the LDNS. This leads to the analysis of elements and isotopes within sub-s times and allows for high-speed nondestructive inspection.
中野 秀仁*; 片渕 竜也*; Rovira Leveroni, G.; 児玉 有*; 寺田 和司*; 木村 敦; 中村 詔司; 遠藤 駿典
Journal of Nuclear Science and Technology, 59(12), p.1499 - 1506, 2022/12
被引用回数：2 パーセンタイル：28.39(Nuclear Science & Technology)A neutron monitoring detection system was developed for neutron capture cross section measurement using a spallation neutron source. A combination of a plastic scintillator and a thin 
LiF foil was adopted for the detector. The detector system was tested to study the feasibility of the system. Neutron irradiation experiments were conducted with the Accurate Neutron-Nucleus Reaction Measurement Instrument in the Materials and Life Science facility of the Japan Proton Accelerator Research Complex. A neutron time-of-flight spectrum was successfully measured without significant count loss or detector paralysis. The statistical uncertainty reached 0.7% at neutron energies around 6 meV.
Am neutron capture cross section measurement and resonance analysisRovira 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*
JAEA-Conf 2022-001, p.91 - 96, 2022/11
Neutron capture cross section measurements were performed in the Accurate Neutron Nucleus Reaction Measurement Instrument (ANNRI) at the Materials and Life Science Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC). The time-of-flight (TOF) methodology was employed in a non-filter condition experiment to determine the neutron capture cross section from thermal to about 100 eV. Moreover, experiments were performed using the neutron filtering system to determine the neutron capture cross section at the energy of 23.5 keV using Fe as filter material. In this study, the preliminary results of the Am neutron capture cross section from 10 meV to about 100 eV determined in TOF experiments and at 23.5 keV from Fe filter experiments are presented. In the TOF experiments, the Am neutron capture cross section was normalized by means of the saturated resonance method using a Au sample with a mass of 1.5 g. In addition, for the Fe filter experiments, the capture cross section of Am at the energy of 23.5 keV was determined relative to the Au yield obtained from a measurement using the same Au sample. Moreover, early-stage results of a resonance analysis of the Am capture resonances are also 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：9.64(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.
