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遠藤 駿典; 木村 敦; 中村 詔司; 岩本 修; 岩本 信之; Rovira Leveroni, G.
EPJ Web of Conferences, 281, p.00012_1 - 00012_5, 2023/03
In resonance analysis, experimental uncertainties affect the accuracy of resonance parameters. A resonance analysis code REFIT can consider the statistical uncertainty of the experimental data in evaluation of the resonance parameter uncertainty. On the other hand, since the systematic uncertainties of the sample thickness and normalization, which is proportional to the cross-section, are not independent at each measurement point, they must be treated differently from the statistical uncertainty. However, their treatment has not been discussed in detail so far. In this study, we evaluated the effect of the systematic uncertainties of experimental data on deduced resonance parameters by varying sample-thickness values used for the REFIT code. Covariance of resonance parameters ascribed to systematic uncertainties were evaluated from the neutron transmission data of natural zinc measured at the J-PARC MLF ANNRI. We will introduce this evaluation method and discuss the feature of obtained correlations.
櫻井 洋亮*; 佐藤 博隆*; 足立 望*; 諸岡 聡; 戸高 義一*; 加美山 隆*
Applied Sciences (Internet), 11(11), p.5219_1 - 5219_17, 2021/06
被引用回数：3 パーセンタイル：30.84(Chemistry, Multidisciplinary)As a new method for evaluating single crystal and oligocrystal, pulsed neutron Bragg-dip transmission analysis/imaging method is being developed. In this study, a single Bragg-dip profile fitting analysis method was newly developed, and applied for analyzing detailed inner information in a crystalline grain position-dependently. In the method, the spectrum profile of a single Bragg-dip is analyzed at each position over a grain. As a result, it is expected that changes of crystal orientation, mosaic spread angle and thickness of a perfect crystal can be evaluated from the wavelength, the width and the integrated intensity of the Bragg-dip, respectively. For confirming this effectiveness, the method was applied to experimental data of position-dependent Bragg-dip transmission spectra of a Si-steel plate consisting of oligocrystals. As a result, inner information of multiple crystalline grains could be visualized and evaluated. The small change of crystal orientation in a grain, about 0.4
, could be observed by imaging the Bragg-dip wavelengths. By imaging the Bragg-dip widths, both another grain and mosaic block in a grain were detected. Furthermore, imaging results of the integrated intensities of Bragg-dips were consistent with the results of Bragg-dip width imaging. These small crystallographic changes have not been observed and visualized by previous Bragg-dip analysis methods.
Ma, F.; Kopecky, S.*; Alaerts, G.*; 原田 秀郎; Heyse, J.*; 北谷 文人; Noguere, G.*; Paradela, C.*; 
alamon, L.*; Schillebeeckx, P.*; et al.
Journal of Analytical Atomic Spectrometry, 35(3), p.478 - 488, 2020/03
被引用回数：3 パーセンタイル：22.14(Chemistry, Analytical)The use of Neutron Resonance Transmission Analysis to characterize homogeneous samples not fulfilling good transmission geometry conditions is discussed. Analytical expressions for such samples have been derived and implemented in the resonance shape analysis code REFIT. They were validated by experiments at the time-of-flight facility GELINA using a set of metallic natural copper samples. The expressions were used to derive sample characteristics by a least squares adjustment to experimental transmission data. In addition, the resonance parameters of Cu for energies below 6 keV, which are reported in the literature and recommended in evaluated data libraries, were verified. This research was implemented under the subsidiary for nuclear security promotion of MEXT.
伊藤 大介*; 佐藤 博隆*; 齊藤 泰司*; Parker, J. D.*; 篠原 武尚; 甲斐 哲也
Journal of Visualization, 22(5), p.889 - 895, 2019/06
被引用回数：1 パーセンタイル：7.41(Computer Science, Interdisciplinary Applications)Solidification process of lead-bismuth eutectic (LBE) is one of the key phenomena to prevent flow channel blockage accident in an LBE-cooled accelerator-driven system. However, the solidification of liquid metal cannot be observed optically and it is difficult to detect noninvasively. In this study, the one-dimensional solidification process of the LBE was visualized by pulsed neutron transmission imaging. Neutrons have higher transmittivity to the LBE than X-ray and neutron transmission spectrum of the LBE sample can be obtained by pulsed neutron imaging technique. The solid and liquid phases of the LBE were identified during the solidification process by the presence or absence of Bragg edge in the measured neutron transmission spectrum, and the transient behavior of the solid-liquid interface could be visualized. In addition, the characteristic spatial distribution of the crystalline structure was found in Bragg-edge transmission image after the solidification.
石川 裕卓*; 甲斐 哲也; 佐藤 博隆*; 加美山 隆*
Journal of Nuclear Science and Technology, 56(2), p.221 - 227, 2019/02
被引用回数：3 パーセンタイル：31.89(Nuclear Science & Technology)We simultaneously measured neutron spectra and the temperature of a polyethylene moderator at the Hokkaido University Neutron Source (HUNS) driven by a compact electron accelerator to observe the effect of any temperature change on the reliability of spectroscopic transmission measurement. The ratio of the neutron effective temperature and the moderator temperature was constant in HUNS case, although both increased by 4-5 K within one hour after the start of accelerator-operation. This indicated that the neutron effective temperature was well estimated by the moderator temperature. The effect of the temperature change can be easily avoided by excluding data collection before the moderator warms up. These results suggested that the monitoring of moderator temperature is recommended in such neutron sources with a thermal neutron moderator to guarantee reliability of spectroscopic transmission measurement without sacrifices of cost, simplicity and maintainability.
奥地 拓生*; 富岡 尚敬*; Purevjav, N.*; 柴田 薫
Journal of Applied Crystallography, 51, p.1564 - 1570, 2018/12
被引用回数：2 パーセンタイル：20.9(Chemistry, Multidisciplinary)中性子準弾性散乱(QENS)は、鉱物結晶格子内で起こる原子スケール水素拡散プロセスを分析するための新規かつ有効な方法であることが実証されている。この方法は、凝縮体中の拡散性が高い水素原子または水分子の拡散頻度および距離を分析するために敏感であると以前から考えられていた。本論文では、水酸基として結晶格子に結合している非常に遅い運動の水素原子の拡散運動を分析する応用研究の結果が示されている。ブルーサイト鉱物( brucite)、Mg(OH)
では、水素原子の単一の二次元層面内でのジャンプとそれに最も近い次の層へのジャンプの2種類の水素拡散プロセスが観察された。ブルーサイトの結晶構造内で観察されるこれらの拡散プロセスは、層状構造を有する様々な種類の酸化物およびミネラル内で起こる水素拡散現象にQENS測定が適用可能であることを示している。
北谷 文人; 土屋 晴文; 藤 暢輔; 堀 順一*; 佐野 忠史*; 高橋 佳之*; 中島 健*
KURRI Progress Report 2017, P. 99, 2018/08
As a non-destructive analytical technique for nuclear material in the field of nuclear security and nuclear nonproliferation, a neutron resonance transmission analysis (NRTA) attracts attention of researchers. It is important to downsize a NRTA system when it is deployed at various facilities. For this aim, we have developed a compact NRTA system which utilizes a D-T neutron generator. Its pulse width of 10
s is much longer than that of a large electron beam accelerator. It is necessary to understand the influence of pulse widths on the NRTA measurement. Therefore, we conducted the experiments of the simulated nuclear fuel pin samples to evaluate how the NRTA measurement is influenced by the pulse width of neutron beam. Experiments were performed in Kyoto University. The simulated fuel pellet sample was made from metallic powders of Ag (around 1%) and Al (around 99%). The energy of the irradiation neutron is determined by a Time of Flight technique. We used three pulse widths of the neutron beam of 0.1, 1 and 4 s. A resonance dip of 
Ag at 5.19 eV is observed in the all spectra. And the dip of the TOF spectrum shifts towards low energy, with pulse width changed to a longer one. In this work, we confirmed that neutron pulse width affected the NRTA measurement of the fuel pin sample. On the basis of this work, we will be able to quantify the effects of long-pulse width in a resonance analysis.
土屋 晴文; 北谷 文人; 藤 暢輔; Paradela, C.*; Heyse, J.*; Kopecky, S.*; Schillebeeckx, P.*
Proceedings of INMM 59th Annual Meeting (Internet), 6 Pages, 2018/07
In fields of nuclear safeguards and nuclear security, non-destructive assay (NDA) techniques are needed in order to quantify special nuclear materials (SNMs) in nuclear fuels. Among those techniques, active NDA ones would be preferable to passive ones. One candidate of active NDA techniques is neutron resonance transmission analysis (NRTA). In fact, experiments done at GELINA have shown that NRTA has high potential enough to quantify SNMs in complex materials. Currently, such a NRTA system requires a large electron accelerator facility to generate intense neutron sources. In other words, it is very difficult to perform NRTA at various facilities that need to measure SNMs. Thus, downsizing a NRTA system would be one solution of its difficulty. In order to realize a compact NRTA system, we develop a prototype with a D-T neutron generator that has a pulse width of 10 s. For this aim, numerical calculations to optimize the compact NRTA system were done. In addition, NRTA measurements with simulated fuel pins were made at neutron time-of-flight facilities such as GELINA. In this presentation, we present results of the numerical calculations and the experimental results. On the basis of those results we discuss a future prospect of a compact NRTA system that would be applicable to SNM quantification. This research was implemented under the subsidiary for nuclear security promotion of MEXT.
勅使河原 誠; 池田 裕二郎; 大井 元貴; 原田 正英; 高田 弘; 柿白 賢紀*; 野口 学*; 島田 翼*; 清板 恭一*; 村島 大亮*; et al.
Nuclear Materials and Energy (Internet), 14, p.14 - 21, 2018/01
被引用回数：0 パーセンタイル：0.01(Nuclear Science & Technology)J-PARCの1MWパルス中性子源では、中性子パルスの成形に用いるデカップラとして、異なる共鳴吸収材から構成し、1eVと高い中性子吸収エネルギーを有するAg-In-Cd合金を開発した。このデカップラによりパルス成形された中性子は、粉末解析の実験装置において最高分解能を更新したが、中性子照射によって生成される長半減期の108mAgの放射能が高いため使用済み機器の取扱においては短所であった。そこで、放射能を大幅に減らす代替材としてAuを使用したAu-In-Cd材の開発を行ってきた。しかしながら、実機のモデレータ・反射体に実用化する上で、大型のAu-In-Cd板と構造材のA5083材とをHIP接合し十分な接合強度を得ることが課題であった。本研究では、Au-In-Cd材の表面状態、大型化した熱容量の変化による接合部界面温度に関わる検討を行い、実規模大のHIP接合において、最適接合条件を見つけることができた。この結果、反射体へのAu-In-Cd材の実用化に成功し、中性子性能を損なわず、大幅な放射能低減の見通しを得た。
北谷 文人; 土屋 晴文; 小泉 光生; 高峰 潤; 堀 順一*; 佐野 忠史*
EPJ Web of Conferences, 146, p.09032_1 - 09032_3, 2017/09
被引用回数：0 パーセンタイル：0.08(Nuclear Science & Technology)The use of a short flight path is effective in the neutron resonance analysis. On the other hand, such a short path would reduce a time resolution in Time-Of-Flight (TOF) measurements. In order to investigate the effect of neutron flight-path length, we carried out Neutron Resonance Transmission Analysis (NRTA) experiments with a short neutron flight path at the Kyoto University Research Reactor Institute - Linear Accelerator (KURRI-LINAC). In measurements of Neutron Resonance Densitometry, the quantity of nuclear materials is determined from TOF spectra obtained in the neutron energy range below 30 eV. Performing NRTA experiments with a 7-m flight path at KURRI-LINAC, we examined effects of flight path and pulse width on a TOF spectrum. A resonance dip of 
W at 27 eV in a TOF spectrum was successfully observed with an electron pulse width less than 2 s. In this presentation, we will discuss importance of the pulse width and short flight path to study design of a compact TOF facility to quantify nuclear materials.
岡 弘; 丹野 敬嗣; 大塚 智史; 矢野 康英; 上羽 智之; 皆藤 威二; 大沼 正人*
Nuclear Materials and Energy (Internet), 9, p.346 - 352, 2016/12
被引用回数：21 パーセンタイル：88.83(Nuclear Science & Technology)The effect of thermo-mechanical treatments (TMTs) on the evolution of nano-structure in an oxide dispersion strengthened (ODS) ferritic/martensitic steel (Fe-9Cr-2W-0.22Ti-0.36YO
) was investigated. TMTs involve hot extruding and subsequent forging, which are expected to be part of a future industrial-scale manufacturing process of the ODS steel. It was shown that the ODS steel was composed of two phases - a fine-grained residual ferrite phase and a transformable martensite phase. The number density of the nano-sized particles in the residual ferrite phase was significantly higher than that in the martensite phase. The TMTs did not significantly affect the number density, but slightly affected the size distribution of the nano-sized particles in both ferrite phase and martensite phase. Moreover, the volume fraction of the residual ferrite phase decreased after TMTs. In summary, the TMT conditions could be a parameter which affects the nano-structure of the ODS steel.
大場 洋次郎*; 諸岡 聡; 佐藤 博隆*; 佐藤 信浩*; 井上 倫太郎*; 杉山 正明*
波紋, 26(4), p.170 - 173, 2016/11
Based on the time-of-light (TOF) technique, new generation pulsed neutron sources enable novel neutron scattering experiments. Using small-angle neutron scattering (SANS) at the pulsed neutron sources, simultaneous measurements of SANS and Bragg edge transmission can be performed. From the SANS profiles, the precipitates and inclusions in metals and alloys are characterized, while the Bragg edge transmission spectra give crystallographic information about the matrix. This is a powerful tool for quantitative characterization of the microstructures in the metals and alloys. The neutron transmission experiments have potential for further development. Magnetic Bragg edge transmission analysis will be useful for magnetic materials. These new neutron scattering techniques enhance the usability and flexibility of neutron scattering experiments.
大場 洋次郎*; 諸岡 聡; 大石 一城*; 佐藤 信浩*; 井上 倫太郎*; 足立 望*; 鈴木 淳市*; 土山 聡宏*; Gilbert, E. P.*; 杉山 正明*
Journal of Applied Crystallography, 49(5), p.1659 - 1664, 2016/10
被引用回数：13 パーセンタイル：66.73(Chemistry, Multidisciplinary)Pulsed neutron sources enable the simultaneous measurement of small-angle neutron scattering (SANS) and Bragg edge transmission. This simultaneous measurement is useful for microstructural characterization in steel. Since most steels are ferromagnetic, magnetic scattering contributions should be considered in both SANS and Bragg edge transmission analyses. An expression for the magnetic scattering contribution to Bragg edge transmission analysis has been derived. The analysis using this expression was applied to Cu steel. The ferrite crystallite size estimated from this Bragg edge transmission analysis with the magnetic scattering contribution was larger than that estimated using conventional expressions. This result indicates that magnetic scattering has to be taken into account for quantitative Bragg edge transmission analysis. In the SANS analysis, the ratio of magnetic to nuclear scattering contributions revealed that the precipitates consist of body-centered cubic Cu
Fe
and pure Cu, which probably has 9R structure including elastic strain and vacancies. These results show that effective use of the magnetic scattering contribution allows detailed analyses of steel microstructure.
小泉 光生; 原田 秀郎; Schillebeeckx, P.*
日本原子力学会誌ATOMO
, 58(9), p.563 - 567, 2016/09
東京電力福島第一原子力発電所における冷却材喪失過酷事故により、1-3号炉では炉心溶融が起きたと考えられている。溶融燃料(デブリ)は、一定の冷却期間をおいて取り出される計画となっている。通常の原子炉では、燃料集合体を単位とした核物質計量管理を行っているが、今回のように燃料集合体が溶融した場合、取り出した核物質量を何らかの測定を行った上で計量管理することが求められる可能性がある。そうした中、粒子状溶融燃料中の核物質量を定量可能とする非破壊測定技術として中性子共鳴濃度分析法を考案し、平成24年度より3年間、文部科学省による核不拡散・核セキュリティ分野における新規技術開発課題として技術開発を進めてきた。本解説では、開発した技術を概説するとともに、国際原子力機関等の専門家が集まるワークショップで行った技術実証試験について報告する。
原田 秀郎; 木村 敦; 北谷 文人; 小泉 光生; 土屋 晴文; Becker, B.*; Kopecky, S.*; Schillebeeckx, P.*
Journal of Nuclear Science and Technology, 52(6), p.837 - 843, 2015/06
被引用回数：3 パーセンタイル：25.85(Nuclear Science & Technology)Neutron resonance densitometry (NRD) is a non-destructive analysis method, which can be applied to quantify special nuclear materials (SNM) in small particle-like debris of melted fuel that is formed in severe accidents of nuclear reactors such as the Fukushima Daiichi Nuclear Power Plants. NRD uses neutron resonance transmission analysis (NRTA) to quantify SNM and neutron resonance capture analysis (NRCA) to identify matrix materials and impurities. In order to generalize NRD for the characterization of arbitrary-shaped thick materials, a generalized method to analyze NRTA data has been developed. The method has been applied on data resulting from transmission through non-uniform thick samples with varying areal density of SNM up to 0.253 at/b (
100 g/cm
). The investigation shows that NRD could be used to quantify SNM in not only uniform samples made of small particle-like debris but also non-uniform samples made of large rock-like debris with high accuracy by utilizing the generalized analysis method for NRTA.
瀬谷 道夫; 小林 直樹; 直井 洋介; 羽島 良一; 曽山 和彦; 呉田 昌俊; 中村 仁宣; 原田 秀郎
Book of Abstracts, Presentations and Papers of Symposium on International Safeguards; Linking Strategy, Implementation and People (Internet), 8 Pages, 2015/03
原子力機構では、2011年度より次の3つのプログラムからなる先進核物質非破壊測定技術の基礎開発を実施している。(1)レーザー・コンプトン散乱
線(大強度単色線)を使う核共鳴蛍光NDA技術開発、(2)ZnS/BOセラミックシンチレータによる中性子検出技術開発、(3)中性子共鳴透過分析(NRTA)及び中性子共鳴捕獲分析(NRCA)による中性子濃度分析法(NRD)技術開発。これらのプログラムは2014年度に終了する予定であり、2015年2-3月に実証試験を行う予定である。
代谷 誠治*; 三澤 毅*; 宇根崎 博信*; 市原 千尋*; 小林 圭二*; 中村 博*; 秦 和夫*; 今西 信嗣*; 金澤 哲*; 森 貴正
JAERI-Tech 2004-025, 93 Pages, 2004/03
JAERI-Tech-2004-025.pdf:6.69MB
本研究では、京都大学原子炉実験所の将来計画に関連して、(1)高エネルギー中性子の物質透過実験,(2)京都大学臨界集合体実験装置(KUCA)における加速器駆動未臨界炉(ADSR)模擬実験,(3)MCNP-Xコードによる京都大学原子炉(KUR)型ADSRの概念的核設計を行い、ADSR型の研究用中性子源の実現に資するとともに、ADSR一般の開発に向けた炉物理的課題を抽出することを目的とした。本研究を通じて、ADSRの基本的特性の概略を理論的,実験的に把握することができ、今後の研究を推進するうえで必要な基礎的知見が得られた。その知見をあえて一言で表現すれば、予想に違わず、ADSRの基本特性は未臨界炉の基本特性に大きく左右されるということである。今後、ADSRの実現に向けて、より詳細な研究を着実に積み上げることが必要と考えられるが、そのためには、(1)核データのより一層の精度向上,(2)未臨界度測定や高エネルギーから低エネルギー領域に及ぶ中性子束の絶対値測定などのADSRを対象とした炉物理実験手法の確立,(3)核破砕中性子発生挙動から遅発中性子挙動の取り扱いを含むADSR関連の解析ツールの整備が必要不可欠である。
森岡 篤彦; 佐藤 聡; 落合 謙太郎; 逆井 章; 堀 順一; 山内 通則*; 西谷 健夫; 神永 敦嗣; 正木 圭; 櫻井 真治; et al.
Journal of Nuclear Science and Technology, 41(Suppl.4), p.109 - 112, 2004/03
定常炉心試験装置(JT-60SC)のポート部分の中性子遮へいは、ポリエチレンよりも温度特性に優れたレジン(商標名: KRAFTON)を使用した設計となっている。超伝導コイルの核発熱量低減のための遮へい性能を保ちつつ、ポート重量を軽減させるため、筆者らはレジンに天然ボロンを添加した、ボロン入りレジンを開発した。ボロン添加量を変えた数種類の試料に、DD反応で発生する2.45MeV中性子を照射し、透過中性子を測定し、ボロン入りレジンの遮へい性能を比較した。高速中性子の遮へい性能はボロン添加量に依存せず同じであった。一方、低エネルギー中性子の遮へい性能はボロン2重量%の試験体がボロン1重量%の試験体より約25%良く、ボロン添加の効果が観測された。
Vacik, J.; Hnatowicz, V.*; Cervena, J.*; 楢本 洋; 山本 春也; Fink, D.*
Fullerene Science and Technology, 9(2), p.197 - 209, 2001/05
本研究では、RBS法,NDP法及びアルファ粒子分光法を用いて、1H, 3H, 4Heや7Liがフラーレン薄膜に入射した時のstopping cross sectionsが測定された。測定値は系統的に計算値よりも大きくなった。この原因としては、イオン入射によるフラーレン薄膜の化学的状態変化と関連していると考えられる。一方energy stragglingに関しても、Bohrによる計算値よりも大きい値が得られた。これに関しては、試料薄膜の厚さの変動によるものと想定される。
高田 弘; 明午 伸一郎; 仁井田 浩二*
Advanced Monte Carlo for Radiation Physics, Particle Transport Simulation and Applications, p.949 - 954, 2001/00
原研とKEKによる統合計画の大強度加速器施設の核設計に用いるため、核子・中間子輸送コードNMTC/JAMについて、高エネルギー核反応計算モデルの導入に関連して、発生するすべての中間子、バリオン、レプトンの輸送を取り扱う拡張を加えたほか、核子-原子核散乱断面積及び弾性散乱角度分布をより正確に扱えるように系統式を修正した。また、ビーム照射による損傷評価のためはじき出し損傷断面積評価計算機能を評価した。改良したNMTC/JAMを用いて、中性子の遮蔽体透過実験解析や厚いターゲットにおける反応率分布測定の解析を行った。前者について、NMTC/JAMによる計算結果は透過成分及び周辺への散乱成分ともに実験値とよく一致した。またGeV領域に陽子入射に関して、中性子生成量が従来よりも増加し、反応率分布について実験値との一致度が向上した。
