※ 半角英数字
 年 ~ 
検索結果: 26 件中 1件目~20件目を表示


Initialising ...



Initialising ...


Initialising ...


Initialising ...


Initialising ...


Initialising ...


Initialising ...


Initialising ...



New material exploration to enhance neutron intensity below cold neutrons; Nanosized graphene flower aggregation

勅使河原 誠; 池田 裕二郎*; Yan, M.*; 村松 一生*; 須谷 康一*; 福住 正文*; 能田 洋平*; 小泉 智*; 猿田 晃一; 大竹 淑恵*

Nanomaterials (Internet), 13(1), p.76_1 - 76_9, 2023/01

 被引用回数:0 パーセンタイル:0.05(Chemistry, Multidisciplinary)



Improvement of neutron diffraction at compact accelerator-driven neutron source RANS using peak profile deconvolution and delayed neutron reduction for stress measurements

岩本 ちひろ*; 高村 正人*; 上野 孝太*; 片岡 美波*; 栗原 諒*; 徐 平光; 大竹 淑恵*

ISIJ International, 62(5), p.1013 - 1022, 2022/05

 被引用回数:0 パーセンタイル:0(Metallurgy & Metallurgical Engineering)

Neutron diffraction is a powerful non-destructive method for evaluating the microscopic structure and internal stress of metal plates as a bulk average. Precise neutron diffraction measurements with a high intensity neutron beam have already been carried out at large-scale neutron facilities. However, it is not easy to provide users with enough experimental opportunities. We are working on upgrading the neutron diffractometer with techniques of time-of-flight to enable stress measurements at RIKEN accelerator-driven compact neutron source (RANS). To improve neutron diffraction resolution, delayed neutrons, which expand neutron beam pulse width, should be suppressed. However, it is difficult to separate the delayed neutrons experimentally. In this study, a new analysis method has been proposed to deconvolute the diffraction peak from the delayed neutron component. Moreover, a new collimator system, called decoupled collimator system, has been developed to reduce the number of delayed neutrons. The diffraction patterns from a powder sample of pure body-centered cubic iron were measured with the decoupled collimator and the diffraction peak of {211} reflection was analyzed by the new analysis method using a model function of a single exponential decay function convoluted with a Gaussian function. By this method, the decoupled collimator system has been confirmed to achieve a smaller measurement limit of lattice strain $$Delta$$$$varepsilon$$ than a small-aperture polyethylene collimator system and a non-collimator system. The currently available $$Delta$$$$varepsilon$$ was 6.7$$times$$10$$^{-4}$$, this means that the internal stress up to 130 MPa can be well evaluated for steel materials with a Young's modulus of 200 GPa at RANS.


小型加速器中性子源RANSを使用した鋼材特性の分析技術開発; ものづくり現場で中性子線を使った材料分析が可能に

徐 平光; 高村 正人*; 岩本 ちひろ*; 箱山 智之*; 大竹 淑恵*; 鈴木 裕士

Isotope News, (774), p.7 - 10, 2021/04



Optimization of a slab geometry type cold neutron moderator for RIKEN accelerator-driven compact neutron source

Ma, B.*; 勅使河原 誠; 若林 泰生*; Yan, M.*; 橋口 隆生*; 山形 豊*; Wang, S.*; 池田 裕二郎*; 大竹 淑恵*

Nuclear Instruments and Methods in Physics Research A, 995, p.165079_1 - 165079_7, 2021/04

 被引用回数:1 パーセンタイル:0.02(Instruments & Instrumentation)

理研加速器駆動型小型中性子源における冷中性子モデレータの最適化を行った。安全かつ管理の容易な物質であるメシチレンをモレデータ材として選択し、粒子・重イオン輸送計算コードシステム(PHITS)を用いて、20Kメシチレンモデレータに室温ポリエチレン(PE)プレモデレータ組み合わせ、スラブ形状で結合した冷中性子の最適化を行った。冷中性子強度を増加させるために、メシチレンとPEの厚さ, 反射体、及び遮へい配置のパラメータを検討した。中性子発生ターゲットから2mの位置で冷中性子強度1.15$$times$$10$$^{3}$$n/cm$$^{2}$$/$$mu$$Aを達成した。これは現在のPEモデレータの12倍である。メシチレンが冷中性子モデレータ材料として魅力的なモデレータ材であることを示した。


In-house texture measurement using a compact neutron source

徐 平光; 池田 義雅*; 箱山 智之*; 高村 正人*; 大竹 淑恵*; 鈴木 裕士

Journal of Applied Crystallography, 53(2), p.444 - 454, 2020/04


 被引用回数:6 パーセンタイル:64.69(Chemistry, Multidisciplinary)

In order to improve the instrumental accessibility of neutron diffraction technique, the emerging compact neutron sources and in-house neutron diffractometers as a good complementary way have caused wide attention while their analysis precision seems problematic for the practical application. As a challenging project, the RIKEN accelerator-driven compact neutron source (RANS) was employed to establish the technical environment for texture measurement, and the recalculated pole figures and the orientation distribution function (ODF) of an interstitial-free (IF) steel sheet obtained from RANS were compared with the results from another two neutron diffractometers well-established for texture measurement. Moreover, the parameter "square integration of ODF difference" originally for evaluating the numerical error between the measured and simulated textures was generalized here to examine the reliability of RANS texture measurement. These quantitative comparisons revealed that the precise neutron diffraction texture measurement at RANS has been realized successfully and the following technical optimizations are much valuable, including the thickness selection of polyethylene moderator, the sample-to-detector distance, the B$$_{4}$$C shielding sheets for the reduced background noise, and the fine region division of the neutron detector panel. Moreover, the Rietveld texture analysis improves the texture reliability through avoiding the unfavorable influence of the uncertain diffraction intensity involved in the low counting, long wavelength incident neutrons at large scattering angles. Above technical results may accelerate the development of other easily accessible engineering materials evaluation techniques using compact neutron source, and also help to improve the data-collecting efficiency for various time-sliced scattering experiments at large neutron facilities.


Convergence behavior in line profile analysis using convolutional multiple whole-profile software

熊谷 正芳*; 内田 知宏*; 村澤 皓大*; 高村 正人*; 池田 義雅*; 鈴木 裕士; 大竹 淑恵*; 浜 孝之*; 鈴木 進補*

Materials Research Proceedings, Vol.6, p.57 - 62, 2018/10

 被引用回数:0 パーセンタイル:0.2

The convergence behavior of the parameters related to microstructural characteristics $$a$$-$$e$$ was studied during optimizations in a common line profile analysis software program based on the convolutional multiple whole profile (CMWP) method. The weighted sums of squared residual (WSSR) was a criterion of the optimization. The parameters $$b$$ and $$d$$, which are related to the dislocation density and to the crystallite size, respectively, strongly affect the line profile shape. Therefore, the distributions of WSSRs on the space parameters $$b$$ and $$d$$ were first observed. The variation trajectory of parameters $$b$$ and $$d$$ during iterative calculations with several values of parameter $$e$$ was then observed, along with the variations when all of the parameters were variable. In the case where only three parameters were variable, we found that a smaller initial value of $$e$$ should be chosen to ensure stability of the calculations. In the case where all parameters were variable, although all of the results converged to similar values, they did not precisely agree. To attain accurate optimum values, a two-step procedure is recommended.


Determination approach of dislocation density and crystallite size using a convolutional multiple whole profile software

村澤 皓大*; 高村 正人*; 熊谷 正芳*; 池田 義雅*; 鈴木 裕士; 大竹 淑恵*; 浜 孝之*; 鈴木 進補*

Materials Transactions, 59(7), p.1135 - 1141, 2018/07

 被引用回数:7 パーセンタイル:43.07(Materials Science, Multidisciplinary)

Neutron diffraction profile analysis using the whole profile fitting method is useful for obtaining microscopic information on metallic materials. To determine an appropriate fitting approach for obtaining reasonable and non-arbitrary results, we applied diffraction line profile analyses using the Convolutional Multiple Whole Profile (CMWP) method to diffraction patterns obtained using the Engineering Materials Diffractometer (TAKUMI, BL19) at the Materials and Life Science Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC). The tensile specimens of 780 MPa grade bainitic steel were uniaxially stretched until the plastic strain reached a value of 0.05. We performed CMWP analyses on the obtained diffraction patterns during tensile test with various initial parameters of dislocation density and crystallite size. These parameters were optimized in the fitting procedures to minimize the weighted sums of squared residuals (WSSRs). Following this approach, we found that unsuitable initial parameter values resulted in unreasonable convergence. Therefore, initial fitting parameters should be chosen to ensure that the initial profiles are as broad as possible. Reasonable results were obtained following this suggestive approach even when the strain anisotropy parameter is set to arbitrary values.



池田 義雅*; 高村 正人*; 箱山 智之*; 大竹 淑恵*; 熊谷 正芳*; 鈴木 裕士

鉄と鋼, 104(3), p.138 - 144, 2018/03

 被引用回数:4 パーセンタイル:21.11(Metallurgy & Metallurgical Engineering)



Development of multi-colored neutron talbot-lau interferometer with absorption grating fabricated by imprinting method of metallic glass

關 義親; 篠原 武尚; Parker, J. D.*; 矢代 航*; 百生 敦*; 加藤 宏祐*; 加藤 秀実*; Sadeghilaridjani, M.*; 大竹 淑恵*; 鬼柳 善明*

Journal of the Physical Society of Japan, 86(4), p.044001_1 - 044001_5, 2017/03

 被引用回数:13 パーセンタイル:69.61(Physics, Multidisciplinary)

パルス中性子源において効率的な位相イメージングを行うために、複数波長で機能する多色Talbot-Lau干渉計を設計・開発した。J-PARC物質・生命科学実験施設のエネルギー分解型中性子イメージング装置「螺鈿」において、中心波長0.25, 0.50, 0.75nmそれぞれに由来する異なるビジビリティーのモアレ縞を同一セットアップで確認することで、その動作原理の実証を行った。さらに、入射波長の波長分解能を18%から50%まで変化させながら、モアレ縞のビジビリティーの減衰を測定し、高波長分解能が実現できるパルスビームの利点を示した。さらに、中心波長0.5nmを用いて、アルミニウム、鉛、銅のロッドをテストサンプルとしたイメージングも行い、吸収像に加えて、境界がエンハンスされた微分位相像、ビジビリティー像も取得することに成功した。この干渉計では、アナライザー用吸収格子の製作方法として、初めて金属ガラスのインプリント法を採用した。中心波長でのモアレ縞のコントラストは68%と良好であり、従来のガドリニウムの斜め蒸着法を用いた格子と比較すると、形状の精密なコントロールが可能である。


Prospect for application of compact accelerator-based neutron source to neutron engineering diffraction

池田 義雅*; 竹谷 篤*; 高村 正人*; 須長 秀行*; 熊谷 正芳*; 大場 洋次郎*; 大竹 淑恵*; 鈴木 裕士

Nuclear Instruments and Methods in Physics Research A, 833, p.61 - 67, 2016/10

 被引用回数:37 パーセンタイル:97.31(Instruments & Instrumentation)



Texture evaluation in ductile fracture process by neutron diffraction measurement

須長 秀行*; 高村 正人*; 池田 義雅*; 大竹 淑恵*; 浜 孝之*; 熊谷 正芳*; 鈴木 裕士; 鈴木 進補*

Journal of Physics; Conference Series, 734(Part B), p.032027_1 - 032027_4, 2016/09

 被引用回数:0 パーセンタイル:0.03



Non-destructive texture measurement of steel sheets with compact neutron source "RANS"

高村 正人*; 池田 義雅*; 須長 秀行*; 竹谷 篤*; 大竹 淑恵*; 鈴木 裕士; 熊谷 正芳*; 浜 孝之*; 大場 洋次郎*

Journal of Physics; Conference Series, 734(Part B), p.032047_1 - 032047_4, 2016/08

 被引用回数:4 パーセンタイル:84.1



Compact neutron sources for energy and security

上坂 充*; 小林 仁*; 呉田 昌俊; 糠塚 重裕*; 西村 和哉*; 井頭 政之*; 堀 順一*; 鬼柳 善明*; 田儀 和浩*; 關 善親*; et al.

Reviews of Accelerator Science and Technology, 8, p.181 - 207, 2015/00



Design of neutron beamline for fundamental physics at J-PARC BL05

三島 賢二*; 猪野 隆*; 酒井 健二; 篠原 武尚; 広田 克也*; 池田 一昭*; 佐藤 広海*; 大竹 淑恵*; 大森 整*; 武藤 豪*; et al.

Nuclear Instruments and Methods in Physics Research A, 600, p.342 - 345, 2009/02

 被引用回数:25 パーセンタイル:84.57(Instruments & Instrumentation)

J-PARC、物質$$cdot$$生命科学実験施設(MLF)のBL05ポートに基礎物理実験のための新しいビームラインを建設している。このビームラインは中性子光学の高度な技術を駆使して設計されており、NOP(Neutron Optics and Physics)と名づけられている。中性子モデレータから供給される中性子ビームは、マルチチャンネルのスーパーミラーで曲げられ、低発散, 高強度, 高偏極という3本の特徴あるビームブランチに分岐された後、実験エリアに引き出され、中性子干渉, 散乱, 崩壊という基礎物理実験に各々利用される。本研究では、モンテカルロシミュレーションコードである"PHITS"を使って中性子光学素子構成及び遮蔽設計の最適化を実施し、低発散ブランチで$$9.2 times 10^5/$$cm$$^2/mu$$str$$/$$s$$/$$MW、高強度ブランチで$$1.2 times 10^9/$$cm$$^2/$$s$$/$$MW、高偏極ブランチではビーム偏極率99.8%を保った状態で$$4.0 times 10^8/$$cm$$^2/$$s$$/$$MWのビーム強度を得ることができるという評価結果を得た。


Neutron diffraction bulk texture measurement using compact neutron source

徐 平光; 角田 龍之介*; 高村 正人*; 大竹 淑恵*; 鈴木 裕士

no journal, , 

Neutron diffraction is a powerful probe to acquire the bulk averaged information for better bridging the microscopic crystal lattice with the macroscopic properties, in contrast with the X-ray and electron diffractions which are capable for investigating the surface/very limited local regions of polycrystalline materials. In Japan, the RIKEN compact accelerator-driven neutron source facility (RANS) has been developing to improve the instrumental accessibility of neutron diffraction experimental studies, which were mostly carried out on large-scale neutron source facilities. Here, our latest technical progress in RANS neutron diffraction bulk texture measurement will be reported. The comparable study between RANS and another large-scale neutron diffraction facility suggests that the high stereographic resolution realized through the proper fine division of neutron detector panel is valuable to improve the precision and reliability of texture measurement, together with the careful scattering intensity correction of neutron patterns.


Energy resolution evaluation of decoupled neutron moderator for stress measurements via neutron diffraction with compact neutron source

角田 龍之介*; 高村 正人*; 徐 平光; 岩本 ちひろ*; 高梨 宇宙*; 大竹 淑恵*; 栗原 諒*; 高橋 進*; 鈴木 裕士

no journal, , 

During the production of high-strength steel structural parts, the residual stress is necessary to be well controlled for the better dimensional accuracy and the longer service life. The neutron diffraction measurement is a good candidate to monitor the microscopic lattice strain of polycrystalline materials in bulk average. RANS (Riken Accelerator-driven Compact Neutron Source) has been developed and upgraded aiming at in-house, on-site and on-demand measurements to meet with industrial needs. Recently, the phase volume fractions and the bulk textures of steel materials have been measured successfully at RANS. In order to measure the lattice strain at RANS, it is required to improve the energy resolution to observe slight peak shift, and the decoupled moderator is thought as a good solution method for that. In this study, a new decoupled moderator consisting of polyethylene with 20 cmm thickness and B$$_{4}$$C rubber was designed and fabricated, and its neutron beam characteristic was investigated in order to improve the time energy resolution to realize in-house neutron stress measurement at RANS. Here, the preliminary results of the resolutions comparing between the new decoupled moderator and the traditional coupled moderators with 20 and 40 mm thickness polyethylene will be reported together with the scattering angle dependent instrumental resolution of the linear neutron position-sensitive detector.



徐 平光; 高村 正人*; 池田 義雅*; 角田 龍之介*; 高橋 進*; 箱山 智之*; 岩本 ちひろ*; 大竹 淑恵*; 鈴木 裕士

no journal, , 

自動車の軽量化のために使用されている高張力薄鋼板は、プレス成形による加工性が低いことから、生産不良が多い。そのため、プレス成形性を向上させる手段の一つとして、鋼材の集合組織制御に期待が寄せられている。実用に供される金属材料の微視組織は不均一な集合組織を有している。圧延板の加工性など金属材料のマクロな特性を議論する際には、金属材料のバルク平均の集合組織を考慮することが適切だと考えられる。中性子線を用いた集合組織測定は、高い透過性と大きなゲージ体積という特徴を生かして、加工性に直結する金属材料のバルク平均情報を容易に測定することができる。しかしながら、日本国内に限らず、世界中には、集合組織が測定できる中性子回折装置が極めて少ない。そこで、我々は研究用原子炉施設(JRR-3)の定常中性子源と大強度陽子加速器施設(J-PARC)のパルス中性子源を用いた集合組織測定技術を確立し、世界トップレベルの測定精度を有する集合組織測定装置を開発した。近年、中性子評価技術をより広く普及するため、理化学研究所が"いつでも、どこでも、手軽に利用できる"をキャッチフレーズとした小型中性子源(RANS)の開発を進めており、我々がこれまでに培ってきたノウハウを最大限に生かして、RANSを用いた粉末回折技術や集合組織測定技術の開発に挑戦してきた。本発表では、JRR-3, J-PARCおよびRANSで開発した鉄鋼材料の集合組織測定技術を簡単に紹介するとともに、中性子回折による集合組織測定研究に関して大型中性子施設と小型中性子源との連携案について議論する。


Neutron diffraction with RANS for industrial "on-site" applications

高村 正人*; 岩本 ちひろ*; 徐 平光; 角田 龍之介*; 栗原 諒*; 箱山 智之*; 池田 義雅*; 鈴木 裕士; 大竹 淑恵*

no journal, , 

High strength steels are becoming more and more important in automotive body structures for good weight reduction, providing further requirement in the balance between strength and formability. Numerical models in forming simulations taking into account the texture evolution may accurately analyze macroscopic plastic behavior, through referring to local surface texture measurement using Electron backscatter diffraction or X-ray diffraction. In contrast, neutron diffraction may measure the microstructure factors including bulk-averaged texture, enable to more deeply understand the mechanisms of deformation behavior. Such neutron diffraction studies usually require large-scale experimental facilities like a reactor and a large accelerator, so meet certain difficulty in the instrumental accessibility. To solve these problems, Riken Accelerator-driven Compact Neutron Source (RANS) has been developed. On-site evaluation of microstructural factors enables us to analyze metal deformation processes more efficiently. Authors have recently succeeded in accurately measuring the texture evolution of an IF steel and also in determining the retained austenite volume fraction of multi-phase steels, by optimizing the beam condition and layout of collimators, samples, detectors, etc. These results show the possibility of practical use of an in-house compact neutron source in laboratories of universities, research institutes and industrial firms.


In-house texture measurement using RIKEN accelerator-driven compact neutron source

徐 平光; 高村 正人*; 池田 義雅*; 角田 龍之介*; 岩本 ちひろ*; 箱山 智之*; 大竹 淑恵*; 鈴木 裕士

no journal, , 

Neutron diffraction is known as a powerful probe to determine the bulk averaged microstructural factors of metals and alloys. Compact neutron sources are being paid much attention for providing wide instrumental accessibility towards many potential on-site neutron diffraction applications, because of less technical complexity compared with large-scale neutron facilities. Here, the RIKEN Accelerator-Driven Compact Neutron Source (RANS) has been developed to establish the in-house technical environment of engineering diffraction for texture measurements. The measured texture of an interstitial-free (IF) steel sheet at RANS was found well consistent with the corresponding result obtained from a large-scale high-resolution time-of-flight neutron diffractometer. Such comparison suggests that RANS may be used to evaluate the ex situ texture characteristics of steel materials. Moreover, the increment of the output power and the addition of the neutron detector will be carried out in near future to enable rapid microstructural factor measurement of other high value-added metallic materials.


ものづくり現場における小型中性子源の利用; 金属加工への活用

高村 正人*; 岩本 ちひろ*; 徐 平光; 上野 孝太*; 栗原 諒*; 鈴木 裕士; 大竹 淑恵*

no journal, , 

Plastic forming processes of metallic sheets, ${it e.g.}$, forging, rolling, bending, pressing, drawing, and extruding, are important manufacturing methods to produce complex mechanical parts. Numerical simulation using the finite element method based on the crystal plasticity theory has been thought valuable to improve the forming accuracy and reduce the forming defects, especially for high strength automotive metallic sheets. For the realization of reliable numerical modelling and the development of strength-formability well-balanced novel metallic sheets, the bulk average microstructure information closely related to the mechanical characteristics is highly expected to be on-site available, or at least may be measured in time through neutron diffraction. Towards these on-site neutron diffraction measurement requirements from forming process designers and materials researchers, RIKEN has developed an accelerator-driven compact neutron source (RANS) and realized the texture and phase fraction measurement at a good precision level. Recently, a novel residual measurement technique using RANS is being carried out.

26 件中 1件目~20件目を表示