Analysis and mapping of detailed inner information of crystalline grain by wavelength-resolved neutron transmission imaging with individual Bragg-dip profile-fitting analysis

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

https://doi.org/10.3390/app11115219

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.

Visualization of phase distribution in lead-bismuth eutectic during one-dimensional solidification process

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

https://doi.org/10.1007/s12650-019-00572-7

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.

Magnetic scattering in the simultaneous measurement of small-angle neutron scattering and Bragg edge transmission from steel

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

https://doi.org/10.1107/S1600576716013133

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 CuFe 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.

Diffractometer for neutron crystallography in biology

新村 信雄; 田中 伊知朗*; 峯崎 善章; 唐沢 裕子*; 田中 勲*; 三木 邦夫*; 佐藤 衛*; 日高 昌則*; 皆川 宣明; 森井 幸生

Physica B; Condensed Matter, 213-214, p.786 - 789, 1995/00

https://doi.org/10.1016/0921-4526(95)00280-M

タンパク質・DNA等の生体物質の水素の位置及び、それらの配位水の水素の位置を決定するための装置が生体物質中性子回折計である。生体物質中性子回折計では、試料位置での中性子束が強く、かつ、ビーム分散の小さい中性子束が必要で、そのためのモノクロメーターが開発された。又、結晶からのBragg反射を出来るだけ多く観測できるように大面積の中性子検出器を設置した。その他種々の工夫を凝らした生体物質中性子回折計を製作し、卵白リゾチーム単結晶からのbragg反射パタンを得ることに成功した。

高エネルギーX線領域でのサジタルフォーカシング・モノクロメータの特性

柏原 泰治*

JAERI-M 91-008, 48 Pages, 1991/02

JAERI-M-91-008.pdf:0.86MB

8GeV級ストレージリングから放射される高エネルギーの光を単色化し、試料位置に集光するのに、サジタルフォーカシング・モノクロメータが利用される。この論文では、入射X線と結晶表面とのなす角、およびX線動力学理論から導かれるダーウィン幅を10~100keVのエネルギー範囲で、Si(111)、Si(311)、Si(333)、Ge(111)、Ge(311)、Ge(333)についてそれぞれ求めた。サジタルフォーカシング・モノクロメータを用いた集光配置では、発散した入射ビームの入射角は、ブラッグ角からはずれる。それゆえ、発散したビームの入射角とブラッグ角のずれを種々の幾何学配置で求めた後、発散ビームがモノクロメータから散乱される条件とダーウィン幅の数値結果を用いて検討した。

Bragg Curve Ionization Chamber for Particle Identification

村上 哲也*; 池添 博; 冨田 芳明; 鹿園 直基

JAERI-M 9514, 20 Pages, 1981/06

JAERI-M-9514.pdf:0.68MB

ブラッグカーブ電離箱を粒子弁別用検出器として開発した。この検出器は、陰極、フリッシュグリッドそれに、陽極より成り、陰極窓を通過して入射する粒子をフリッシュグリッドと陰極間のガス中で止める。ガス中で電離した電子は陰極・フリッシュグリッド間の一様電場の中を陽極に向って動き、集められ、入射粒子のブラッグ曲線が陽極からの電流信号として得れる。ブラッグ曲線のピーク値は原子番号を与え、積分値は入射粒子のエネルギーを与える。又、その曲線の全幅は飛程を与える。これら3つの量は同時に測定され、粒子弁別のために使用された。この結果、原子番号の分解能Z/ZZは、ブラッブピーク値対飛程スペクトルの解析より、約50であった。

X-ray emission spectra induced by ion-atom collisions, 2; Effects of chemical bonding and multiple ionization on X-ray spactra

川面 澄

Rev.Phys.Chem.Jpn., 47(2), p.69 - 79, 1977/02

H(0.3-1.8MeV),He(0.25-2.0MeV),N(0.3-1.1Mev),Ne(0.3-0.85Mev)及びAr(0.3-1.8MeV)イオン衝撃によって、Be及びBeOのBe KX線B及びBNのB KX線及び酸化物のO KX線スペクトルとCr,Mn,Fe及びCoのL X線スペクトルを高分解能のBraggスペクトロメータで測定した。Kの主、衛星及び超衛星線やその遷移エネルギーは化学結合や入射イオンによって大きい影響を受ける。特に重イオンで励起された場合にこの効果は著しい。更に、K及びLX線の多重内殻電離効果は入射イオンの核電荷に大きく依存することが示された。

Applications of optical fiber remote strain measurement in nuclear energy maintenance

西村 昭彦

no journal, , 

This paper reports on the achievements and prospects of remote strain measurement based on FBG sensing in nuclear applications. In 2020, JAEA began technology transfer to deltfiber.jp for the fabrication of FBG sensors using picosecond laser precision machining. test machining was performed using a laser system, a microscope machining device, and a high-precision linear stage. The radiation resistance and polarization-maintaining characteristics of the optical fiber used for laser machining were evaluated to select the optimal fiber. FBG sensors can be implemented in a variety of applications. Current applications include heavy machinery such as cranes deployed at decommissioning sites, drum cams for conveniently holding drums, manipulators for handling radioactive materials, and monitoring earthquake-induced deformation of cooling pipes.

Strain and microstructure distributions around a fatigue crack tip by neutron Bragg-edge imaging and diffraction

Su, Y. H.; Parker, J. D.*; 篠原 武尚; 及川 健一; 甲斐 哲也; Gong, W.; Harjo, S.; 川崎 卓郎; 相澤 一也; 鬼柳 善明*

no journal, , 

Fatigue damage is known as one of the major concerns in maintaining the integrity of large-scale engineering components. The nonlinear strain/stress distribution around a fatigue crack tip has a great impact to understand the fatigue and crack growth behavior of engineering component. We consider that it is possible to reveal local variations in strain and microstructure around a fatigue crack tip throughout the thickness of the material by using the non-destructive Bragg-edge imaging and diffraction probes. To investigate the influence of austenitic and ferritic phases on the changes in the strain and microstructure of steels during cyclic fatigue, we selected a typical single austenite stainless steel SUS304 and a duplex stainless steel SUS329J4L. The fatigue tests on the compact-tension samples were conducted with a servo-hydraulic fatigue testing machine. The pulsed Bragg-edge imaging experiment on the fatigued samples was performed at BL22 RADEN in MLF/J-PARC. The time-of-flight neutron diffraction strain mapping was performed at BL19 TAKUMI in MLF/J- PARC. Two-dimensional maps of inhomogeneous residual strain and microstructure for the samples, which had been under different fatigue loading conditions, were determined by Bragg-edge spectral analysis. The obtained Bragg-edge imaging results were quantitatively compared with those determined by diffraction. Surface strains measured by digital image correlation during the fatigue tests will also be presented.